HEP Phenomenology·hep-ph

Tue·Jul 28, 2026Tuesday·July 28, 2026

58 papers—41 primary·17 cross-listed

01
Application of flavor moonshine
Hirotaka Sugawara🇯🇵
In our previous paper [1], we presented the application of Moonshine to the flavor physics based on the work of Cohn and Deutsch [2] and Bagger and West. Conway and S. Norton [3] and T.Eguchi, H.Ooguri and Y.Tachikawa[4]. We present here the extension of our previous paper [1] by including the supersymmetry and the modular symmetry. We calculate all the lepton masses and the quark masses and their super partner masses by using the one input particle mass for each family. The two valued modular function is defined in equation(7). We define the two valued modular function of degree K in equation (7). We use K = 1 two valued modular function for the charged leptons and k = 2 two valued modular function for the neutrino and for the up quarks and k = 3 two valued modular function for the down quarks. We emphasize that we have three particle masses which can be measured by the existing accelerators such as KEK B factory or CERN LHC. One is super electron mass "Me,s =847 MeV" which is slightly lower than the proton mass. The Super d, s and b quark masses are 0 GeV, 5.56 GeV, and 2193.4 GeV. Super down quark mass is 0 and super strange quark mass can be measured both in KEKB and in CERN LHC. The super bottom quark mass can be measured only in LHC.
hep-phhep-th0 citations
02
Axion isocurvature and the model-building problem of low-scale inflation
Sarunas Verner🇺🇸
The pre-inflationary QCD axion is often said to require low-scale inflation. We derive a general isocurvature bound for a light axion with a scale-invariant spectrum, treating its inflationary normalization $f_{I}$ independently of the late-time decay constant $f_{a}$ and allowing for an arbitrary axion dark matter fraction, nontrivial perturbation transfer, and the full anharmonic abundance response. In the minimal benchmark, where axions constitute all of the dark matter, $f_{I} = f_{a} \leq M_{Pl}$ , and the angular perturbation is conserved, the least restrictive CMB limit considered gives the 95% C.L. upper bound $H_{I} < 1.25 \times 1 0^{10} GeV$ on the inflationary Hubble scale. For an initial misalignment angle $θ_{i} = 1$ , the bound strengthens to $H_{I} < 2.2 \times 1 0^{7} GeV$ , with still stronger constraints near the hilltop. Combining the isocurvature and tensor spectra yields axion-tensor and axion-conditioned Lyth bounds. If the observed curvature perturbation is generated by a canonical cold single-field slow-roll inflaton and the tensor amplitude varies slowly across the observable CMB window, these relations limit the inflaton excursion to $Δ ϕ_{CMB} / M_{Pl} ≲ 1 0^{- 7} - 1 0^{- 4}$ and require $∣ M_{Pl} V^{'} / V ∣ \sim 1 0^{- 8} - 1 0^{- 5}$ while $M_{Pl}^{2} V^{''} / V \sim - 1 0^{- 2}$ . This hierarchy favors models with independent control of the inflationary scale, potential derivatives, exit, and reheating, including hybrid, running-mass, and inflection-point models. Reheating and the requirement of Peccei-Quinn non-restoration sharpen these conditions, while nonminimal scenarios can relax them by modifying the primordial fluctuation, its transfer, or the relic abundance.
hep-phastro-ph.COgr-qc0 citations
03
Agentic Re-Casting using Agentic Re-Simulations
Sascha Diefenbacher🇩🇪 · Tilman Plehn🇩🇪 · Daniel Schiller🇩🇪 · Nikita Schmal🇩🇪
Analysis re-casting at the LHC is highly standardized and nevertheless requires resources, time, and physics input. Building on the new MadAgents.v3, we show how a global SFitter analysis can be updated by an agentic system with a physicist in the loop. The agentic interface allows us to make the advanced SFitter methodology available to a wider audience. All physical and technical aspects of this agentic re-casting study can be trivially generalized beyond SFitter.
hep-ph3 citations
04
$SNuDD$ : Solar Neutrinos for Direct Detection
Dorian W. P. Amaral🇪🇸 · David Cerdeño🇪🇸 · Andrew Cheek🇨🇳 · Valeria Costa🇪🇸 · Patrick Foldenauer🇪🇸
We introduce Solar Neutrinos for Direct Detection ( $SNuDD$ ): an open-source Python package that enables the computation of the solar neutrino rate spectrum at direct detection experiments. $SNuDD$ can be used to determine the differential rate for both nuclear and electron recoils within the Standard Model and in the presence of beyond Standard Model physics effects, such as those arising from neutral-current non-standard interactions (NSI). The package accounts for matter effects during neutrino propagation through both the Sun and the Earth and for modifications to the scattering cross sections at the interaction site. We employ $SNuDD$ to place new limits on the effective NSI couplings using results from the xenon-based direct detection experiments LZ, XENONnT, and PandaX-4T, and we project the sensitivity of a future xenon detector based on the planned XLZD and PandaX-xT observatories. We find that current direct detection experiments are rapidly approaching sensitivities comparable to those of dedicated neutrino experiments and that future xenon detectors can provide leading constraints. We recommend that $SNuDD$ be used to combine incoming direct detection data with those from neutrino experiments in future global fits, placing direct detection within the broader landscape of neutrino physics.
hep-phastro-ph.CO0 citations
05
Properties of $Ω_{cc b}$ and $Ω_{bb c}$ baryons in a quark-diquark model
Chaitanya Anil Bokade🇮🇳 · Bhaghyesh
In this work, we investigate the mass spectra and radiative transitions of $Ω_{cc b}$ and $Ω_{bb c}$ baryons within a relativistic screened potential model using the quark-diquark approximation to capture key aspects of their internal structure. The model describes the $S$ -, $P$ -, and $D$ -wave excitations, provides corresponding mass predictions, and offers a comparison with other theoretical approaches. Our findings suggest that excitations involving the diquark occur at lower energies than those requiring relative motion between the quark and diquark, challenging conventional assumptions about the rigidity of heavy diquark systems. Analysis of radiative decays of these states, shows that spin-flip transitions within the same orbital multiplet are suppressed, while transitions involving orbital or radial changes dominate with significantly larger widths. The model offers subtle distinctions in excitation dynamics and highlights its value for future studies and for interpreting potentially upcoming experimental results on triply heavy baryons.
hep-ph0 citations
06
Exact Phenomenology of the Neutrino Cuboid: Normal Mass Ordering, the Tribimaximal Limit, and Cosmological Constraints
Jianlong Lu🇸🇬
We investigate the exact phenomenology of a geometric neutrino cuboid defined by $m_{1} = m_{0} sin ξ$ , $m_{2} = m_{0} cos ξ sin ζ$ , and $m_{3} = m_{0} cos ξ cos ζ$ , whose cubic point corresponds to mass degeneracy and the tribimaximal values of the solar and atmospheric mixing angles. Imposing the mass-mixing alignment $ξ = θ_{12}$ and $ζ = θ_{23}$ , we derive closed-form consistency relations without relying on an expansion about the cubic limit. These relations show that the observed condition $sin^{2} θ_{12} < 1/3$ selects normal mass ordering and, in the resulting normal-ordering regime, the physical condition $0 < Δ m_{21}^{2} /Δ m_{31}^{2} < 1$ requires $θ_{23}$ to lie in the lower octant. Representative JUNO-based inputs give $sin^{2} θ_{23} ≃ 0.440$ , $(m_{1}, m_{2}, m_{3}) ≃ (0.0938, 0.0942, 0.1063) eV$ , and $\sum_{i} m_{i} ≃ 0.294 eV$ . We demonstrate that the first-order expansion around the tribimaximal point is numerically unstable for the solar-to-atmospheric mass-splitting ratio because of a leading-order cancellation. Present atmospheric-angle data yield only mild tension with exact alignment, whereas stringent neutrino-mass bounds in baseline $Λ$ CDM cosmology strongly disfavor it; its viability under extended cosmological models remains model dependent. We finally formulate geometric alignment residuals as general null-test observables, providing a systematic framework for testing the neutrino cuboid with future oscillation and absolute-mass measurements.
hep-ph0 citations
07
Testing selectively enhanced QCD axions couplings as an explanation of the RX J1856.5-3754 hard X-ray excess
Charul Rathod🇮🇳 · Madhukar Mishra🇮🇳 · P.K Das🇮🇳
We explore the possibility of explaining hard X-ray data obtained from one of the Magnificent Seven (M7) neutron-stars (NSs) employing QCD axion-converted photons. The emission of thermal axions along with neutrinos from the core has been considered. We adopt the nucleon-nucleon bremsstrahlung process as the baseline axion production mechanism and Cooper-pair breaking and formation (PBF) as an additional process. We investigate here whether the selectively enhanced QCD axion coupling model can better explain the hard X-ray excess than the commonly used KSVZ axion model. Our results suggest that meV-mass QCD axions cannot explain the hard X-ray observation within the adopted framework. The enhanced selective model in the micro-eV scale provides closer agreement with the hard X-ray data. We thus conclude that the emission of hard X-rays in the $2 - 8$ keV range from isolated M7 stars could be explained by QCD axions under an enhanced coupling scenario.
hep-phastro-ph.HE0 citations
08
High-frequency gravitational waves from axion inflation in the weak-backreaction regime
Xun-Jie Xu🇨🇳 · Junyu Zhu🇨🇳
Axion inflation, characterized by a Chern-Simons interaction between the inflaton and a gauge field, provides a powerful mechanism for generating primordial gravitational waves (GWs) through tachyonic enhancement of the gauge field. While recent literature has predominantly focused on the Strong Backreaction (SB) regime to maximize GW signals for future interferometers, this regime suffers from computational complexities as well as the risk of overproducing scalar perturbations. In this work, we investigate gauge field amplification and GW production strictly within the theoretically safer Weak Backreaction (WB) regime, with a particular focus on the largely unexplored non-instantaneous reheating phase. Because the tachyonic enhancement during slow-roll typically increases as inflation approaches its end, it is crucial to investigate how the production of GWs behaves at the very end of inflation and thereafter. By continuously tracking the evolution from slow-roll through reheating to radiation domination, we present a complete picture of inflationary and post-inflationary GW production in this framework. A particularly interesting feature of the post-inflationary phase is that the oscillatory behavior of the inflaton during reheating leads to frequent sign-flips of the instability parameter $ξ$ , exciting both helical modes of the gauge field. Our analysis reveals that axion inflation can naturally generate one of the strongest known primordial GW signals at high-frequency bands. The yield is relevant for future precision measurements of the effective number of neutrino species, $N_{eff}$ , and also strongly motivates the development of novel high-frequency GW detectors.
hep-phastro-ph.CO0 citations
09
Quasi-two-body decays $B_{c}^{+} \to χ_{c 0, c 1} [ρ (K^{*}) \to] π π (K π)$ in the PQCD approach
Jun Deng🇨🇳 · Xian-Qiao Yu🇨🇳
We study the quasi-two-body decays $B_{c}^{+} \to χ_{c 0, c 1} [ρ (K^{*}) \to] π^{+} π^{0} (K^{0} π^{+})$ in the perturbative QCD framework at leading order. The $π π$ and $K π$ pairs are produced via the P-wave resonances $ρ (770)$ , $ρ (1450)$ , $ρ (1700)$ , and $K^{*} (892)$ , parametrized by the Gounaris-Sakurai and relativistic Breit-Wigner models. The $ρ$ channels, dominated by the $ρ (770)$ resonance, yield $B (B_{c}^{+} \to χ_{c 0} π^{+} π^{0}) = 7.33 \times 1 0^{- 4}$ and $B (B_{c}^{+} \to χ_{c 1} π^{+} π^{0}) = 1.02 \times 1 0^{- 3}$ , with constructive $ρ$ interference making the coherent total $\sim 26%$ -- $30%$ larger than the $ρ (770)$ contribution alone. The Cabibbo-suppressed $K π$ channels yield branching ratios roughly a factor of five below those of the $π π$ modes, $B (B_{c}^{+} \to χ_{c 0} K^{0} π^{+}) = 1.49 \times 1 0^{- 4}$ and $B (B_{c}^{+} \to χ_{c 1} K^{0} π^{+}) = 1.94 \times 1 0^{- 4}$ , the Cabibbo suppression being only partially compensated by the narrow $K^{*} (892)$ resonance and the normalization factor $N_{K^{*}} = 1.48$ . For $χ_{c 1}$ modes, $f_{L} \approx 93%$ dominates and decreases with increasing resonance mass. The ratio $R_{χ_{c 1} / χ_{c 0}}^{π π} \approx 1.38$ reflects the common resonant $ρ$ production mechanism shared by $χ_{c 0}$ and $χ_{c 1}$ , with the charmonium decay-constant hierarchy and phase space determining the relative yield of P-wave charmonia. The analogous ratio in the Cabibbo-suppressed $K π$ channel, $R_{χ_{c 1} / χ_{c 0}}^{K π} \approx 1.30$ , is consistent with this value, confirming that the spin ratio is governed by charmonium-side dynamics.
hep-ph0 citations
10
Novel Multilepton Signatures from the Fermionic Portal to Vector Dark Matter
Alexander Belyaev🇬🇧 · Manimala Chakraborti🇬🇧 · Claire Shepherd-Themistocleous🇬🇧 · Chang-Yuan Yao🇬🇧
We perform a collider study of a novel multilepton signature arising from pair production of heavy vector-like leptons followed by cascade decays through a dark sector. In the muonic realisation of the Fermionic Portal to Vector Dark Matter, this process can lead to final states with four, six, eight, or ten visible muons, depending on the dark-sector spectrum and branching pattern. We identify the six-muon channel as the most powerful target: it remains sizeable over a broad region of parameter space, while being less rate-suppressed than the higher-multiplicity channels and much cleaner and more reconstructable than the four-muon final state. The signal arises from Drell--Yan pair production of vector-like muons, $pp \to μ^{' +} μ^{' -}$ , followed by decays through the dark vector $V^{'}$ and the dark scalar $H_{D}$ . The six-muon final state receives contributions from symmetric decay topologies in which each $μ^{'}$ yields three visible muons, and from the asymmetric topology in which one chain yields one muon and the other yields five. The six-lepton signature from vector-like-lepton pair production has not previously been explored at the LHC. We therefore develop a topology-based reconstruction which exploits the repeated dimuon, trimuon, and five-muon resonance structure of the signal. We simulate signal and Standard Model backgrounds at detector level, including a dedicated treatment of rare heavy-flavour muons. The resulting background after the six-muon selection and topology reconstruction is negligible. Existing Run-2 multilepton searches already constrain part of the low-mass parameter space, but they do not exploit the repeated resonance structure of the signal. A dedicated six-muon search can substantially extend the reach. At the HL-LHC, the proposed analysis can probe vector-like muon masses up to about $1.9$ TeV for favourable spectra.
hep-ph0 citations
11
A Chromomagnetic Mechanism for the Rotational Phase Transition of Gluonic Matter
Zhibin Li🇨🇳 · Yidian Chen🇨🇳 · Mei Huang🇨🇳
Rotation serves as a pivotal control parameter for QCD matter, yet effective models and lattice QCD yield conflicting predictions regarding its effect on the deconfinement transition. Using a rotation-magnetic correspondence within a holographic framework, we investigate the rotational response of pure gluonic matter. Calibrated against lattice QCD data at imaginary angular velocity, we find real rotation enhances chromomagnetic string tension and raises deconfinement temperature, consistent with lattice QCD analytic-continuation predictions. The temperature dependence of chromomagnetic string tension dominates the system's Barnett response: weak low-temperature tension induces the negative Barnett effect, and slightly above the transition, spin contributions prevail to generate an anomalous negative total moment of inertia. Since growing angular velocity further strengthens chromomagnetic string tension and suppresses spin-dominated inversion, this anomalous regime only survives at weak real rotation and vanishes at large angular velocity. At high temperature, fully restored strong string tension stabilizes conventional Barnett behavior. Stemming from the melting and thermal restoration of nonperturbative chromomagnetic flux tubes, our results establish the chromomagnetic-induced inertia inversion (CII) mechanism as the microscopic origin of this anomalous rotational response.
hep-phhep-th1 citation
12
Status of light inflaton: from inflation to laboratory
Niloy Mondal🇮🇳 · Shashwat Sharma🇮🇳 · Mathew Thomas Arun🇮🇳 · Basabendu Barman🇮🇳
We investigate the viability of the light inflaton scenario in light of the latest inflationary constraints from the Atacama Cosmology Telescope (ACT), together with bounds from collider and intensity-frontier experiments searching for a feebly coupled light scalar with a sub-GeV mass. Assuming a quartic inflaton potential, we identify the region of parameter space consistent with the ACT observations and derive constraints on the inflaton mass and inflaton-Higgs mixing using results from NA62, KOTO, BaBar, Belle, LHCb, MATHUSLA, FASER2, SHiP, and neutral meson oscillations. We also explore the prospects for dark matter production during reheating within this framework, while remaining consistent with the inflationary observables.
hep-phastro-ph.COhep-th0 citations
13
Faddeev description of baryons in two-dimensional QCD with $N_{c} = 3$ . I. Chiral spectrum, isospin, and strangeness
Ismail Zahed🇺🇸 · Haocheng Zhang🇺🇸
We develop a light-front Faddeev description of baryons in two-dimensional QCD at $N_{c} = 3$ , in which an exact coupled-channel representation identifies the quark--diquark picture as a single-channel truncation, and solve it variationally with exact matrix elements. In the chiral limit we find an exactly massless lightest baryon, in agreement with the classic valence solutions, DLCQ, and bosonization; the excitation tower reproduces Webber's spectrum state by state and sets the valence gap $1.371 M_{mes}^{*}$ . The channel content distinguishes these states: the massless baryon is single-channel, the gapped states are genuinely multi-channel, and all baryon Regge trajectories are of the meson class. The calculation is anchored at both ends of the coupling range: the meson-to-baryon mass ratio agrees with strong-coupling bosonization to $0.3$ -- $4.3%$ , while the valence masses reproduce the full discretized light cone quantization (DLCQ) masses to $0.04%$ (meson) and $0.15%$ (baryon) at weak coupling. Extending to two degenerate flavors, we find the massless baryon to be the $Δ$ -like quartet, while the $N$ -like doublet at $0.977 M_{mes}^{*}$ is an exact $50 : 50$ superposition of good- and bad-diquark channels. Adding a massive strange quark, we obtain, to our knowledge for the first time at the valence three-quark level, the hyperon spectroscopy of QCD $_{2}$ : $Σ$ -like states fall below $Λ$ -like ones, inverting the four-dimensional ordering, the chiral thresholds count two kaon units per strange quark, and the Gell-Mann--Okubo relation is protected in mass squared. With all three quark masses non-degenerate, the proton-like state falls below the neutron-like one, $Σ^{0}$ -- $Λ$ mixing appears, and the Coleman--Glashow relation holds at the percent level.
hep-ph0 citations
14
Simultaneous Color Glass Condensate fit to deep inelastic scattering and forward hadron production at HERA, RHIC, and the LHC
Piotr Korcyl🇵🇱 · Truong My Hau Le · Farid Salazar🇺🇸 · Tomasz Stebel🇵🇱
We present the first simultaneous fit to deep inelastic scattering (DIS) reduced cross sections from HERA and forward single inclusive hadron production (SIHP) from RHIC and the LHC in which the dipole amplitude is obtained from Balitsky--Kovchegov (BK) evolution within the Color Glass Condensate effective theory. We demonstrate that, using the LO BK equation with running coupling (with or without kinematical constraint) and a constant per-collider $K$ -factor accounting for higher-order corrections, a global $χ^{2} / d.o.f.$ close to unity is achieved in both schemes. The required $K$ -factors are about a factor of two larger at RHIC than at the LHC, remarkably in agreement with threshold-resummed one-loop studies of forward production. In our setup and with the data available, we find the two observables to be complementary: the SIHP data tighten the constraint on the evolution speed of the dipole amplitude without introducing tension with the DIS description. We further quantify the dependence of the $K$ -factors on the fragmentation-function set and the factorization scale, identifying these as the dominant systematic uncertainties to be addressed in future precision analyses of forward hadron production. We perform a full uncertainty analysis using the Hessian method, validated against a Monte Carlo Bayesian inference study.
hep-ph1 citation
15
Effects of flavor-mixings on charged kaon and pion parton distribution functions
Fabio L. Braghin🇧🇷 · Parada T. P. Hutauruk🇯🇵
We investigate the charged kaon and pion parton distribution functions (PDFs) in the U(3) Nambu--Jona-Lasinio (NJL) model, considering a novel flavor-mixing interaction arising from vacuum polarization that differs from the instanton-induced 't~Hooft interaction. In this work, the proper-time regularization scheme is employed, and, effectively, it might take quark confinement into account. The gap equations, the meson masses, and the meson--quark coupling constants are calculated in the presence of flavor mixing interactions. The valence-quark distributions of the charged kaon and pion are calculated and compared with existing experimental data and JAM analysis results at scales $μ^{2} =$ 4 and 27 GeV $^{2}$ . The strength of mixing effects on the PDFs is found to be proportional to the quark effective masses and their differences. We further find that the dominant flavor mixing effects in the pion valence up-quark distribution at scales $μ^{2} =$ 27 and 4 GeV $^{2}$ are around $x ≃ 0.3$ and $x ≃ 0.8$ , while for the kaon, the effects are shown at around $x ≃ 0.2$ and $x ≃ 0.7$ . We also find similar strength of mixing effects on the PDFs at both scales $μ^{2} = 4$ and 27 GeV $^{2}$ ; however, it certainly improves the pion and kaon PDFs.
hep-phhep-exhep-latnucl-th1 citation
16
Probing collective behaviour of Heavy Quarks through $p_{T}$ -differential radial flow $v_{0} (p_{T})$
Salvatore Plumari🇮🇹 · Maria Lucia Sambataro🇮🇹 · Santosh K. Das🇮🇳 · Vincenzo Greco🇮🇹
We discuss the $p_{T}$ -differential radial flow $v_{0} (p_{T})$ of charmed hadrons within a Langevin dynamics coupled to relativistic Boltzmann transport approach in an event-by-event basis. We propose heavy flavour $v_{0} (p_{T})$ as a novel observable to probe the strength of the interaction of heavy quarks with the expanding Quark-Gluon Plasma. By comparing different temperature dependence for the spatial diffusion coefficient $D_{s} (T)$ we show that the $v_{0} (p_{T})$ keep a strong sensitivity to the heavy-quark transport coefficients at intermediate $p_{T}$ . At low $p_{T}$ , the observable is also sensitive to hadronization where we observe a larger $v_{0} (p_{T})$ for $Λ_{c}$ baryons than for $D$ mesons.
hep-ph0 citations
17
Neural Control Variates at LO and NLO
Theo Heimel🇧🇪 · Tilman Plehn🇩🇪 · Rebecca Revelli🇩🇪 · Sophia Vent🇩🇪 · Ramon Winterhalder🇮🇹
We employ neural control variates to minimize the range of event weights and avoid negative weights for phase-space integration and event generation. A signed control variate, built from two normalizing flows, fulfills both tasks. Combined with neural importance sampling, it significantly reduces the computational cost of LO and NLO predictions. For the NLO case, our conditional neural control variate can be viewed as a trainable subtraction term, complementing the established physics subtraction schemes for enhanced sampling performance.
hep-ph4 citations
18
Mass and Decay Properties of Toponium Using SUSY QM Factorization Method
Bhavishya Tepan🇮🇳 · Manan Shah🇮🇳 · P C Vinodkumar🇮🇳
The Supersymmetric quantum mechanics (SUSY QM) factorization method is applied to study the Cornell potential in the context of toponium $(t t ˉ)$ , the heaviest quarkonium system. The method is successfully applied to determine the mass, binding energy, and spin-dependent hyperfine splitting, giving pseudoscalar $(η_{t})$ and vector $(Θ_{t})$ state masses of 344.114 GeV and 344.141 GeV, respectively. The decay properties of both the pseudoscalar and vector states are also investigated through their respective decay widths, highlighting the crucial role of the bound-state wavefunction. Among the decay channels, the di-gluonic $(η_{t} \to g g)$ mode is found to be dominant, with an estimated decay width of 2.57 MeV. In addition, the spatial characteristics of toponium are examined by evaluating the mean radius, root-mean-square (RMS) radius, and most probable radius, all of which are found to lie within the range of $0.015 - 0.025 fm$ .
hep-ph0 citations
19
T-odd transverse momentum dependent gluon distributions for tensor polarized deuteron in a spectator model
Xiupeng Xie🇨🇳 · Zhun Lu🇨🇳
We present a model calculation of the T-odd transverse momentum dependent distribution functions (TMDs) for gluons inside a tensor polarized deuteron. The model is built on the assumption that an on-shell deuteron can emit a time-like off-shell gluon, with the residual system treated as a single on-shell spectator particle. The spectator mass is described via a spectral function, which allows it to take real values over a continuous range. The final-state interaction required to generate nonvanishing T-odd functions are implemented via single-gluon exchange between the spectator and the outgoing parton. We derive analytical expressions for six T-odd gluon TMDs, and present numerical results characterizing their dependence on the longitudinal momentum fraction $x$ and the transverse momentum $k_{T}$ .
hep-ph0 citations
20
Radiative decays $J / ψ, ψ (2 S) \to γ η^{(')}$ in perturbative QCD with relativistic corrections
Jun-Kang He🇨🇳 · Chao-Jie Fan🇨🇳 · Cong Wang🇨🇳
We present the first calculation of the radiative decays $J / ψ, ψ (2 S) \to γ η^{(')}$ in perturbative QCD that includes the order- $q^{2}$ relativistic corrections in all three short-distance contributions, namely the quark-antiquark, two-gluon, and QED contributions. The amplitudes are found to be remarkably insensitive to the light-cone distribution amplitude and to the light-quark mass, a robustness that persists through order $q^{2}$ and makes the predictions correspondingly reliable. The relativistic correction enhances the $J / ψ$ branching ratios by roughly a factor of two, narrowing their shortfall from experiment, whereas for the $ψ (2 S)$ it is about twice as large as for the $J / ψ$ and the low-order expansion converges poorly. In two representative $η$ -- $η^{'}$ mixing schemes, the ratio $R_{1 S} = B (γ η^{'}) / B (γ η)$ proves sharply sensitive to the mixing angle and favours the smaller of the two. The predicted $ψ (2 S)$ rates lie well above the data in both channels, already at leading order, and most severely for the anomalously small $γ η$ channel. Such a discrepancy suggests that a mechanism beyond the hard perturbative process is at work. As a physically motivated attempt, we explore the $η_{c}$ -mixing contribution, which adds coherently to the perturbative one and is comparable to it in the $γ η$ channel, and find that the interference can bring the $ψ (2 S)$ rates into agreement with the data, although its extraction is limited by a strong sensitivity to the mixing parameters.
hep-ph0 citations
21
The Higgs boson decay $h \to b s$ in the NB-LSSM
Cai Guo🇨🇳 · Xing-Xing Dong🇨🇳 · Zhan Cao🇨🇳 · Song Gao🇨🇳 · Shu-Min Zhao🇨🇳 · Tai-Fu Feng🇨🇳
Within the framework of the next to minimum B-L supersymmetric model (NB-LSSM), we investigate the flavor transition process $B ˉ \to X_{s} γ$ . Building upon this foundation, we further discuss the Higgs decay process $h \to b s$ under the constraint from the $B ˉ \to X_{s} γ$ process. Our study reveals that the branching ratio of $h \to b s$ can significantly deviate from the Standard Model (SM) expectation, depending on the values of the new parameters introduced in the model. This finding highlights the modulation of new physics parameters on the Higgs flavor-violating decay and provides important theoretical grounds for exploring new physics beyond the SM through flavor observables.
hep-ph0 citations
22
Electromagnetic form factors of singly charmed baryons $Σ_{c}$ and $Λ_{c}$ in a covariant quark-diquark model
Ye Cao🇨🇳 · Cheng Chen🇨🇳 · Dongyan Fu🇨🇳 · Ju-Jun Xie🇨🇳
We present a systematic study of the spacelike electromagnetic form factors of the ground-state singly charmed baryons, $Σ_{c}$ ( $Σ_{c}^{++}, Σ_{c}^{+}, Σ_{c}^{0}$ ) and $Λ_{c}^{+}$ , within a covariant quark-diquark model. Based on this framework, we obtain their magnetic moments as well as electric charge and magnetic moment radii. Such observables are important to understand the internal structure and the inner dynamics of these heavy baryon states. Our theoretical calculations are in qualitative agreement with available lattice QCD results of $Σ_{c}^{++}$ and $Σ_{c}^{0}$ baryons. We also discuss the mechanism behind the dependence of the numerical results on the charm quark and light diquark. A key finding is that the electric form factors of the singly charmed baryons fall off much more slowly with momentum transfer $Q^{2}$ than that of the proton, indicating a more compact electric charge distribution, which is attributed to the heavy charm quark acting as a localized core. More importantly, we observe a striking difference in the magnetic structure: while the magnetic form factors of $Σ_{c}$ are dominated by the light axial-vector diquark, those of $Λ_{c}^{+}$ are unexpectedly governed by the charm quark due to the vanishing contribution of the scalar diquark. This highlights the decisive role of the light-diquark spin configuration in determining the magnetic properties. Finally, using an empirical asymptotic relation connecting the spacelike and timelike regions, we predict the total cross section for $e^{+} e^{-} \to Σ_{c} Σ ˉ_{c}$ . Our findings can be tested at existing facilities including the BESIII, Belle II and LHCb, as well as the proposed Super Tau-Charm Facility.
hep-phhep-exhep-lat0 citations
23
Effects of Axion Interactions on Quark Stars in 4D Einstein-Gauss-Bonnet Gravity
Rui Zhou🇨🇳 · Ming-zheng-xuan Wu🇨🇳 · Xin-ran Yang🇨🇳 · Chong-long Xie🇨🇳 · Min Zhou🇨🇳 · Zhi-yang Liu🇨🇳 · Shi-jun Mao🇨🇳 · Guo-yun Shao🇨🇳
We explore the properties of quark stars by combining the microscopic axion-extended Polyakov--Nambu--Jona-Lasinio model with the macroscopic framework of four-dimensional Einstein-Gauss-Bonnet (4D EGB) gravity. Our results show that the inclusion of axion-induced interactions stiffens the equation of state of quark matter, thereby increasing the sound speed and the maximum mass of quark stars. The inclusion of the 4D EGB correction effectively weakens gravitational compression and further modifies the stellar structure, allowing for larger radii and higher maximum masses while reducing the compactness and surface gravitational redshift. Notably, the combined effects yield mass-radius sequences that are more compatible with current observational constraints than those obtained under standard general relativity with conventional quark-matter equations of state. These findings suggest that the interplay between axion dynamics and 4D EGB gravity may provide a viable phenomenological framework for describing massive quark stars.
hep-ph0 citations
24
Electroweak Baryogenesis: Advances in Sphaleron Rate Calculations and Implications of Thermal Phase Transitions
Yanda Wu🇨🇳
This thesis reviews recent advances in calculating the sphaleron rate, with particular emphasis on electroweak baryogenesis. It also provides pedagogical introductions to sphaleron- and instanton-induced baryon-number violation, the vacuum structure of non-Abelian gauge theories, and other topological field configurations, and suggests "an zi" as a possible Chinese term for "sphaleron" (see p. 3). Broader implications of first-order phase transitions for collider searches and primordial black hole formation are also discussed.
hep-phhep-th0 citations
25
Quantum entanglement within quarkonium
Wenyu Zhang🇨🇳 · Yiyu Zhou🇨🇳 · Yang Li🇨🇳 · Qun Wang🇨🇳
We investigate quark-antiquark entanglement in heavy quarkonium within a nonperturbative light-front Hamiltonian framework. By tracing over the antiquark degrees of freedom in the hadronic state vector, we construct the reduced density matrix of the quark subsystem and compute the associated von Neumann entropy. For spin-0 quarkonia, we show that this entropy reduces to the Shannon entropy of the unpolarized transverse momentum dependent parton distribution (TMD), up to constant color and spin contributions. For spin-1 quarkonia, we derive the explicit polarization dependence of the entropy and connect it to polarized and tensor-polarized TMDs. Using light-front wave functions obtained via basis light-front quantization (BLFQ), we evaluate the entanglement entropy for charmonium and bottomonium states, revealing a pronounced sensitivity to the polarization of vector mesons. Furthermore, we resolve the infrared parameter by matching the momentum-space entropy to a harmonic-oscillator representation. Ultimately, these results establish entanglement entropy as a novel probe of nonperturbative quarkonium structure, forging a direct link between quantum information measures and partonic observables.
hep-phquant-ph1 citation
26
Prospects for observing the $η_{t}$ $\to$ $W^{+} W^{-}$ decay at the HL-LHC
Yueling Yang🇨🇳 · Bingbing Yang🇨🇳 · Junfeng Sun🇨🇳
Motivated by the recent observation of the pseudoscalar toponium $η_{t}$ at the LHC and by the ongoing interest in its properties, we phenomenologically investigate the $η_{t}$ $\to$ $W^{+} W^{-}$ process, one of the characteristic decays of toponium $η_{t}$ . The branching ratio for the $η_{t}$ $\to$ $W^{+} W^{-}$ decay is estimated with two scenarios of the decay constant $f_{η_{t}}$ . It is found that tens of dilepton events from the cascade decays, $η_{t}$ $\to$ $W^{+} W^{-}$ $\to$ $ℓ^{-} ν ˉ_{ℓ} ℓ^{' +} ν_{ℓ^{'}}$ with $ℓ$ , $ℓ^{'}$ $=$ $e$ and $μ$ , could be experimentally observed, when considering the realistic identification efficiency of the charged lepton and assuming more than $3 \times 1 0^{7}$ $η_{t}$ events available at the future HL-LHC. We propose searching for $η_{t}$ via the $η_{t}$ $\to$ $W^{+} W^{-}$ $\to$ $ℓ^{-} ν ˉ_{ℓ} ℓ^{' +} ν_{ℓ^{'}}$ channel, which features no $b$ -jets and clean dilepton signatures, thus offering a complementary and potentially more sensitive probe.
hep-phhep-exEPJC(2026)·0 citations
27
Studying the tensor resonance contributions in $B \to P P ℓ^{+} ℓ^{-}$ and $B \to P V ℓ^{+} ℓ^{-}$ decays
Ru-Min Wang🇨🇳 · Xiu-Ping Fan🇨🇳 · Si-Yu Xu🇨🇳 · Yi Qiao🇨🇳 · Xiao-Dong Cheng🇨🇳 · Yuan-Guo Xu🇨🇳
We analyze the semileptonic $B \to T ℓ^{+} ℓ^{-}$ , $B \to T (\to P P) ℓ^{+} ℓ^{-}$ , and $B \to T (\to P V) ℓ^{+} ℓ^{-}$ decays with $ℓ = e, μ, τ$ based on flavor SU(3) analysis in the standard model ( $T$ denotes the light tensor meson, $P$ denotes the light pseudoscalar meson, and $V$ denotes the light vector meson). The hadronic amplitudes of the $B \to T ℓ^{+} ℓ^{-}$ decays are related by the nonperturbative parameters, and all branching ratios of the $B \to T ℓ^{+} ℓ^{-}$ decays are obtained by the experimental data of the branching ratio of $B_{s}^{0} \to f_{2}^{'} (1525) μ^{+} μ^{-}$ in three cases, and then the branching ratios of the $B \to T (\to P P) ℓ^{+} ℓ^{-}$ and $B \to T (\to P V) ℓ^{+} ℓ^{-}$ decays are predicted by the narrow width approximation and further considering finite width effects of the intermediate resonances. Compared with the narrow width results, the finite width effects slightly reduce the branching fractions for most decays. However, sizeable finite width effects are found in some near threshold modes. For the subthreshold $K_{2}^{*} (1430) \to K η^{'}$ relevant channels, the finite width of the tensor resonance can open a nonzero contribution. Compared with the measured $B \to P P ℓ^{+} ℓ^{-}$ and $B \to P V ℓ^{+} ℓ^{-}$ decays, we find that the branching ratios with the tensor resonance states are small. Therefore, other resonances, for example, the vector mesons, the scalar mesons, the axial-vector mesons or their excited states, might give the dominant contributions to the relevant decays. Our results might be tested in current and future experiments.
hep-ph0 citations
28
Ultraviolet boundary condition and the Higgs mass
Jinku Guo🇨🇳 · Junqiang Bai🇨🇳
Within the emergence framework, in which infrared physics is not fixed by ultraviolet Lagrangian parameters, the hypothesis that the Higgs quartic coupling vanishes at the Planck scale is tested within the full two-loop Standard Model. With lambda(M_P) = 0 imposed as the sole boundary condition and all other inputs fixed by experiment, a Higgs mass of m_h = 121.99 GeV is obtained from complete two-loop renormalisation-group evolution and full two-loop threshold matching. This lies 3.21 GeV (2.6%) below the measured value of 125.20 GeV. The dominant theoretical uncertainty, +/- 1.5 GeV, arises from unknown three-loop effects and is estimated by perturbative power counting. The calculation tests the simplest ultraviolet boundary condition consistent with the emergence framework of Ref. [1]. The agreement is meaningful at the available precision, since the hypothesis could easily have been excluded by a wide margin. A sharper test requires a complete three-loop calculation and an improved top-quark mass measurement.
hep-ph1 citation
29
A High-Precision Numerical Framework for Time-Varying Solar Neutrino Flux with Full Earth Matter Oscillation Corrections for Global Underground Laboratories
Keyu Han🇨🇳 · Isabella Yin🇨🇳 · Kaoru Yagi🇺🇸 · Kevin Yifan Jiang🇨🇳 · Xiangpan Ji🇨🇳 · Shaomin Chen🇨🇳
Solar neutrinos have been studied for over half a century to test both the Standard Solar Model and the electroweak sector of the Standard Model of particle physics. Contemporary experiments are now entering an era of high-precision measurements, demanding corresponding theoretical predictions with sub-percent accuracy to enable meaningful comparison. In this paper, we identify and analyze the essential physical and computational components required to compute solar neutrino fluxes with high fidelity, and present a unified, computationally efficient framework. This framework incorporates: (i) the time-varying Earth-Sun distance; (ii) Earth matter effects modeled using both one-dimensional (1D) and three-dimensional (3D) Earth electron-density profiles; and (iii) a fast, Strang-splitting-based implementation of the Mikheyev-Smirnov-Wolfenstein (MSW) neutrino propagation formalism, enabling rapid, large-scale scans over neutrino trajectories and energy grids. We deliver site-specific predictions for the China Jinping Underground Laboratory (CJPL) and other underground laboratories actively engaged in solar neutrino programs.
hep-phastro-ph.SRhep-ex0 citations
30
Revisiting relativistic corrections to inclusive $J / ψ$ production at B factories: Complete expansion for three-body quarkonium production
Sheng-Juan Jiang🇨🇳 · Sai Cui🇨🇳 · Guang-Zhi Xu🇨🇳 · Kui-Yong Liu🇨🇳
We revisit the calculations of relativistic corrections to inclusive $J / ψ$ production at B factories. For quark-level subprocesses with three-body final states, we carry out a full expansion of the final-state kinematic parameters. The resulting cross sections are theoretically self-consistent and independent of the choice of integration variables. In the high-energy limit, both cross-section magnitudes and the line shapes of correction curves for energy and momentum distributions agree remarkably well with fragmentation-function calculations. We find that $O (v^{2})$ corrections suppress the cross section by roughly $14.55%$ in the $J / ψ + X_{c c ˉ}$ channel and enhance it by approximately $12.18%$ for the $J / ψ + X_{non- c c ˉ}$ channel. After incorporating published $O (α_{s})$ corrections, color-octet contributions, two-photon production channels, and feed-down effects, tension persists between theoretical predictions and experimental measurements. This indicates that complete prompt-quarkonium calculations through $O (α_{s}, v^{2})$ , or evaluations incorporating higher-order corrections, are required to resolve this tension.
hep-ph1 citation
31
Constraints from the SM-like Higgs boson in a flavor-dependent $U (1)$ extension of the Standard Model
Duong Van Loi🇻🇳 · N. T. Duy🇻🇳
This work presents a phenomenological study of the Standard Model-like Higgs boson $H$ in a flavor-dependent $U (1)_{X}$ extension of the Standard Model, where the $X$ charge is assigned according to fermion flavors. In particular, we analyze the interactions of $H$ with Standard Model particles as well as with new charged scalar bosons. In addition, the parameter $\ka_{\ga}$ , which characterizes the $H \to \ga \ga$ decay at the one-loop level, is investigated. The results show that the model predicts $\ka_{\ga}$ values consistent with the ATLAS and CMS constraints at the $1 σ$ level, while satisfying several bounds derived from flavor, collider and dark matter studies.
hep-phJ.Phys.Conf.Ser.(2026)·0 citations
32
Generation-separated hypercharges and dark charges: origin of flavor, neutrino masses, and dark matter
Duong Van Loi🇻🇳
We study a framework with generation-separated hypercharges and dark charges. After the extended hypercharge symmetry $U (1)_{Y 1} \otimes U (1)_{Y 2} \otimes U (1)_{Y 3}$ is spontaneously broken to the Standard Model $U (1)_{Y}$ , hierarchical masses of charged fermions and small quark mixing can arise from higher-dimensional operators involving hyperon fields. Several realizations with different hyperon sectors are presented to illustrate possible flavor structures. Focusing on the realization with four hyperons, we examine neutrino mass generation through either a seesaw or a scotoseesaw mechanism, which can accommodate tiny neutrino masses and large neutrino mixing. The breaking of the dark gauge symmetry $U (1)_{D}$ leaves a residual $Z_{2}$ symmetry that stabilizes dark matter, allowing either fermionic or scalar candidates with viable TeV-scale parameter regions consistent with the observed dark matter relic abundance and current direct detection constraints.
hep-phJ.Phys.Conf.Ser.(2026)·0 citations
33
Implications of $K \to π ν ν ˉ$ for new physics in $B$ decays
Lukas Allwicher🇩🇪 · Marzia Bordone🇩🇪
The new measurement of the $K^{+} \to π^{+} ν ν ˉ$ branching ratio by the NA62 collaboration represents an important milestone in precision flavour physics. Under different flavour assumptions on beyond the standard model physics, this decay mode can be related to many other observables with underlying flavour-changing currents, such as $B \to K ν ν ˉ$ or $B_{s} \to μμ$ , effectively providing an additional handle in our exploration of flavour-violating new physics effects. We study the impact of this new result, under the hypotheses that deviations from the standard model arise from modified $Z$ couplings, or from effects in semileptonic interactions. Finally, we review the implications of our scenarios for the yet to be measured partner mode $K_{L} \to π^{0} ν ν ˉ$ .
hep-ph2 citations
34
Light Dark Matter Discovery Potential and Model Selection at LDMX
Adam Berger🇸🇪 · Riccardo Catena🇸🇪 · Jan Conrad🇸🇪 · Taylor R. Gray🇸🇪
Light dark matter (DM) is a compelling scenario for the observed relic abundance, with accelerator-based searches as a powerful discovery strategy. The upcoming Light Dark Matter eXperiment (LDMX) is designed to probe light DM by measuring the energy and transverse momentum of recoil electrons in high-intensity electron-nucleus collisions. We evaluate the discovery potential of LDMX to light DM at four benchmark points along the thermal target for complex scalar DM mediated by a dark photon, for different background assumptions, and assess its model selection power at a representative benchmark. We find that LDMX has strong projected 5 $σ$ discovery potential along the relic target across both background scenarios for certain benchmarks, and we further compute projected 90% C.L. exclusion limits assuming no measured signal events. The normalization and shape of the two-dimensional recoil electron distribution encodes the coupling and dark photon mass, respectively, enabling parameter inference in the event of a signal excess. We perform parameter estimation on simulated data and find that both parameters are recovered within their uncertainties along the relic target. We assess whether the data can distinguish between competing dark sector hypotheses, in particular, dark photons with additional higher electromagnetic moment interactions. We demonstrate that model comparison using the Bayes factor allows dark sector hypotheses to be statistically distinguished, with the two-dimensional analysis affording substantially greater discriminating power than the one-dimensional analysis. These results are obtained within a likelihood-based statistical framework, incorporating signal and background modelling with their associated systematic uncertainties and employing both frequentist and Bayesian methods. The framework is designed for direct application to real LDMX data.
hep-phhep-ex1 citation
35
Decay constants of the two-pole $D_{0}^{*} (2300)$
Qi-Wei Yuan🇨🇳 · Jia-Ting Zhang🇨🇳 · Ming-Zhu Liu🇨🇳
The nature of the scalar charmed meson $D_{0}^{*} (2300)$ remains one of the most intriguing states in hadron spectroscopy. A prominent interpretation is a two-pole structure generated by the coupled channels $D π$ , $D η$ , $D_{s} K ˉ$ , and $D η^{'}$ , in which the lower pole couples mainly to $D π$ and the higher pole to $D_{s} K ˉ$ . Following this picture, we calculate the decay constants of these two poles using the effective Lagrangian approach. The resulting values, $f_{D_{0}^{*}}^{(lower)} = 64. 6_{- 1.0}^{+ 0.9} MeV$ and $f_{D_{0}^{*}}^{(higher)} = 80. 8_{- 5.3}^{+ 9.6} MeV$ , are substantially smaller than those predicted by conventional $c q ˉ$ excited-state scenarios. This difference suggests that decay constants can serve as a sensitive probe to discriminate between different internal structures of the $D_{0}^{*} (2300)$ . As a phenomenological application, we further predict the branching fractions for the Cabibbo-favored decays $B_{s} \to D_{s} D_{0}^{*}$ , $Λ_{b} \to Λ_{c} D_{0}^{*}$ , and $Ξ_{b} \to Ξ_{c} D_{0}^{*}$ within the factorization approach. These predictions provide crucial tests to validate the two-pole interpretation of the $D_{0}^{*} (2300)$ .
hep-ph0 citations
36
Invisible decay of solar neutrinos at dark matter experiments
Martina Beccaria🇮🇹 · Veronica Beligotti🇮🇹 · Valentina De Romeri🇪🇸 · Giulia Pagliaroli🇮🇹 · Dimitrios K. Papoulias🇩🇪 · Federica Pompa🇮🇹 · Christoph A. Ternes🇮🇹
The combination of the long baseline and characteristic energies of solar neutrinos offers an ideal framework to probe invisible neutrino decay. In this work we present the first constraint on invisible solar-neutrino decay using coherent elastic neutrino-nucleus scattering, recently observed in dark matter direct detection experiments. Through a combined analysis of nuclear-recoil data from XENONnT, PandaX-4T, and LUX-ZEPLIN, we constrain the lifetime of the neutrino mass state $ν_{2}$ , obtaining a bound already comparable in strength to that from the Sudbury Neutrino Observatory. We further evaluate the sensitivity that could be reached by a future xenon-based dark matter detector. For this projection, we extend the analysis to electronic-recoil data, estimating the impact of detecting lower-energy solar neutrinos from the $pp$ -chain via elastic scattering off electrons. This channel would allow us to place strong constraints on the lifetimes of both the $ν_{1}$ and $ν_{2}$ mass eigenstates. Our results show that, with nominal future exposures, nuclear-recoil data would improve the current bound by about one order of magnitude, while electronic-recoil data would open a new detection channel for low-energy solar neutrinos, surpassing existing dedicated solar-neutrino bounds by 1 to 2 orders of magnitude.
hep-ph0 citations
37
Global analyses of helicity-dependent parton distribution functions
Emanuele R. Nocera🇮🇹
Helicity-dependent, or polarised, parton distribution functions describe the longitudinal polarisation of quarks, antiquarks, and gluons inside a polarised nucleon. They encode how the spin of a fast-moving proton or neutron is shared among its partonic constituents and are therefore central to the modern understanding of nucleon spin structure in Quantum Chromodynamics. Helicity PDFs are extracted from global QCD analyses of polarised hard-scattering data, including inclusive deep-inelastic scattering, semi-inclusive deep-inelastic scattering, and polarised proton-proton collisions. This article reviews the definition and physical interpretation of polarised PDFs, the perturbative QCD framework used to determine them, the experimental observables that constrain the different parton flavours, and the statistical methodology of global analyses. The state of the art in polarised PDF determination is presented, together with the impact expected from future measurements at the Electron-Ion Collider.
hep-phhep-exhep-th2 citations
38
Next-to-leading order FsQED corrections to radiative pion pair production
Carlo M. Carloni Calame🇮🇹 · Marco Ghilardi🇮🇹 · Andrea Gurgone🇮🇹 · Guido Montagna🇮🇹 · Mauro Moretti🇮🇹 · Oreste Nicrosini🇮🇹 · Fulvio Piccinini🇮🇹 · Francesco P. Ucci🇮🇹
We compute the next-to-leading order corrections to the radiative return process $e^{+} e^{-} \to π^{+} π^{-} γ$ within the FsQED approach to embed the pion form factor in the calculation of loop integrals. We compare our results with those of the factorised scalar QED approach, as well as with previous predictions obtained by us in the generalised vector meson dominance model. We show the numerical impact of the structure-dependent corrections on various observables of interest for radiative return experiments at flavour factories. Following recent input from the literature, we include in our calculation also leading corrections beyond FsQED and we provide a first estimate of such contributions. We also investigate additional mechanisms contributing to final-state radiation at center-of-mass energies around the $ϕ$ -meson resonance, such as radiative $ϕ$ decays, presenting numerical results that are relevant for the KLOE experiment. These novel features are implemented in the Monte Carlo event generator BabaYaga@NLO, which can now be used to evaluate the impact of the modelling of pion-photon interaction in radiative return measurements.
hep-phhep-ex1 citation
39
Electromagnetic structure of charged and neutral strange vector mesons
Parada T. P. Hutauruk🇯🇵
We investigate the electromagnetic form factors of the charged $K^{*+} (892)$ ( $u s ˉ$ ) and neutral $K^{0} (896)$ ( $d s ˉ$ ) strange vector mesons within the covariant Nambu--Jona-Lasinio model, employing the Schwinger proper-time regularization scheme to regularize ultraviolet divergences while incorporating the QCD aspect of quark confinement. To this end, we evaluate the charge (electric) $G_{C} (Q^{2})$ , magnetic $G_{M} (Q^{2})$ , and quadrupole $G_{Q} (Q^{2})$ form factors, as well as the charge radii, of the charged $K^{+} (892)$ and neutral $K^{0} (896)$ strange vector mesons. We find the charge radii to be $⟨ r^{2} ⟩_{K^{+}} = 0.45 fm^{2}$ and $⟨ r^{2} ⟩_{K^{0}} = - 0.04 fm^{2}$ , respectively, while the corresponding magnetic moments are $μ_{K^{+}} = 2.67, μ_{N}$ and $μ_{K^{* 0}} = 0.032, μ_{N}$ . These results are consistent with other theoretical calculations and lattice QCD simulations.
hep-phnucl-thPRD(2026)·1 citation
40
The Operational Resistance of Neutrinos: Epistemic Maturity vs. Technological Utility
Neda Razzaghi🇮🇷
Neutrinos represent a quintessential dichotomy in contemporary physics because they are epistemically mature components of our physical theories yet remain remarkably resistant to broad technological deployment. This paper examines the underlying structural asymmetry between scientific reality and technological utility. We argue that epistemic maturity, characterized by precise measurement and theoretical integration, does not automatically confer technological operability. Operability requires the reproducible construction of a signal recovery chain, which, in the case of neutrinos, is systematically hindered by their weak interaction cross sections. To formalize this limitation, we introduce a dimensionless operability index denoted as $O$ , which synthesizes the simultaneous constraints of source power, detector scaling, and information throughput. Through this diagnostic lens, we demonstrate that neutrino based systems are not fundamentally impossible but are instead relegated to a regime of intrinsic engineering inefficiency. We conclude that neutrinos should be understood as epistemically central yet operationally resistant entities, whose engineering value remains limited to niche, strategic applications rather than general purpose communication.
hep-ph0 citations
41
Symbolic Extraction of Non-Perturbative Transverse-Momentum-Dependent Distributions from Drell-Yan Data
Cole Granger🇺🇸 · Alessandro Bacchetta🇮🇹 · Valerio Bertone🇫🇷 · Chiara Bissolotti🇺🇸 · Matteo Cerutti🇫🇷 · Marco Radici🇮🇹 · Simone Rodini🇮🇹 · Lorenzo Rossi🇮🇹 · Cristiano Fanelli🇺🇸
We present an analytical parametrization of the non-perturbative transverse-momentum-dependent (TMD) parton distribution function of unpolarized quarks, extracted from Drell-Yan data using a combination of neural-network fitting and symbolic regression. A factorized neural network is trained directly against experimental cross-section data from fixed-target, Tevatron, RHIC, and LHC experiments at next-to-next-to-next-to-leading logarithmic accuracy, and symbolic regression is subsequently applied to each network component to discover compact analytical expressions. The final formula is selected from a Pareto front in the space of expression complexity and experimental $χ^{2}$ , yielding a closed-form non-perturbative function with 9 free numerical constants that achieves $χ^{2} / ndf = 1.040$ over 482 data points. A non-trivial $x$ - $b_{T}$ cross term is retained even under a sparsity prior that biases it toward zero, indicating a mild but genuine correlation between the longitudinal momentum fraction and the transverse momentum. This work demonstrates that symbolic regression is a viable tool for bridging flexible machine-learning fits and interpretable analytical TMD parametrizations, and opens a systematic path toward data-driven discovery of specific features of non-perturbative QCD.
hep-phnucl-thphysics.data-an0 citations
42
Accurate method for ultralight axion CMB and matter power spectra
Rayne Liu🇺🇸 · Wayne Hu🇺🇸 · Daniel Grin🇺🇸
Ultralight axions (ULAs) with masses $1 0^{- 33} ≲ m / eV ≲ 1 0^{- 12}$ are well motivated in string-inspired models and can be part or all of the dark energy or the dark matter in this range. Since the ULA field oscillates at a frequency $m$ that can be much larger than the expansion rate $H$ , accurate and efficient calculation of cosmological observables requires an effective time averaged treatment. While these are well established for $m ≫ 10 H_{eq}$ , the Hubble rate at matter radiation equality, here we extend and develop these techniques to cover the mass range $1 0^{- 33} ≲ m / eV ≲ 1 0^{- 18}$ . We implement this technique in a full cosmological Boltzmann code ( $AxiECAMB$ ) with numerical precision sufficiently accurate for current and next-generation cosmic microwave background, as well as large-scale structure data analysis. New effects including the time averaging of metric perturbations and hydrostatic equilibrium of the effective fluid result in many orders of magnitude improvements for power spectra accuracy over some previous treatments such as $axionCAMB$ in some extreme regions of parameter space and order unity changes of the ULA effects near $Λ$ CDM models. These improvements may impact the specific model parameters that have been suggested might resolve various tensions in $Λ$ CDM at a comparable level.
↳ astro-ph.COhep-phPRD(2025)·18 citations
43
Fermi--Born--Infeld electrodynamics: a nonlinear theory with physical gauge
Renato Vieira dos Santos🇧🇷
We construct a nonlinear extension of Fermi's electrodynamics by incorporating a Born--Infeld structure that depends directly on the four-potential $A_{μ}$ rather than on the field strength $F_{μν}$ . The resulting theory, which we call Fermi--Born--Infeld (FBI) electrodynamics, eliminates the $U (1)$ gauge redundancy by elevating the Lorenz gauge to a dynamical condition. The Lagrangian is built from the determinant of a metric-like tensor $g_{μν} = η_{μν} + 2 κ \partial_{(μ} A_{ν)}$ , ensuring that the canonical energy--momentum tensor and the spin density remain unique and free of gauge ambiguities. We derive the field equations, which reduce to $\partial_{ν} (- g g^{μν}) = 0$ , and show that the Lorenz condition $\partial_{μ} A^{μ} = 0$ emerges dynamically from retarded boundary conditions and the requirement of a positive-energy spectrum. The nonlinearities modify the propagation of longitudinal modes; we argue, via a Vainshtein-like mechanism, that the nonlinear self-interactions may stabilize the longitudinal mode, opening the possibility of a stable massive scalar photon under extreme field conditions. We also compute the spin density from the Noether current and discuss its properties. The FBI theory preserves the physical gauge of Fermi's original formulation while incorporating the regularization features of Born--Infeld electrodynamics, making it a candidate for describing electromagnetic phenomena in strong-field regimes.
↳ physics.class-phhep-ph0 citations
44
Relativistic Chiral MHD with application to the early Universe
Deepen Garg🇨🇭 · Jennifer Schober🇨🇭
We present a systematic derivation of the equations of relativistic chiral magnetohydrodynamics (MHD) for a plasma of charged fermions in an expanding universe. Through a combination of a coordinate transformation and a rescaling of the dynamical variables, we bring the full system to the same form as in the Minkowski metric, with the Hubble expansion surviving only in the chirality-flipping rate and the kinematic viscosity. Retaining all four contributions to both the electric and the axial current yields terms absent from standard chiral MHD: charge-density corrections to the evolution equations for the chemical potentials, and an electric current proportional to the charge chemical potential $μ$ and the bulk velocity. The latter is mandated by current conservation, requires no chirality imbalance, and drives the charge-flow instability studied in a companion paper. For the radiation-dominated era, we evaluate all the coefficients in physical units and use them to estimate the magnetic Reynolds number, the attainable magnetic field strength, and the minimum temperature at which the chiral dynamo can operate. The resulting equations are cast in a form ready for direct numerical implementation.
↳ astro-ph.COastro-ph.HEhep-phphysics.plasm-ph0 citations
45
Stability in Axion Inflation with Strong Backreaction from a Massive Vector Boson
Michael J. Baker🇺🇸 · Joaquim Iguaz Juan🇺🇸 · Lorenzo Sorbo🇺🇸
We study a modification of the model of axion inflation coupled to a $U (1)$ gauge field where the vector field is massive. In the conventional scenario with a massless gauge field, the onset of the regime where the gauge field strongly backreacts on the inflaton displays an instability whose nonlinear evolution and endpoint remain poorly understood. We argue that, if the gauge field is massive enough, the transition to the strong backreaction regime instead occurs smoothly, avoiding this instability. This observation suggests that axion inflation with massive gauge fields admits a controllable strong backreaction regime, so that a phenomenologically viable realization of inflation might be possible in this class of models.
↳ astro-ph.COhep-phhep-th3 citations
46
Cosmic microwave background temperature cosmography
C. J. A. P. Martins🇵🇹
The temperature-redshift relation, $T (z) = T_{0} (1 + z)$ , is a cornerstone of the standard cosmological model, but it is violated in many physically motivated extensions thereof, e.g. when photon number is not conserved. We apply the methodology of cosmography, a model-independent approach to cosmology, to this observable, and use astrophysical Sunyaev-Zeldovich and high-resolution spectroscopic measurements spanning the redshift range $0 \leq z \leq 6.34$ , to constrain violations of the standard relation. We explore the impact of different cosmographic approaches and expansion variable choices and also compare the cosmographic constraints with those obtained, with the same data, in the canonical adiabatic extension model of Lima. While these choices have some impact, overall we find that such violations are constrained to percent level, and that a single non-standard parameter suffices to describe them. We also show that the directly fitted slope of the temperature-redshift relation is compatible with (but slightly smaller than) the one inferred from FIRAS, and that standard cosmography lore, based on scale factor expansions, does not apply to this observable, e.g. Padé approximants have no meaningful advantage over plain Taylor series.
↳ astro-ph.COgr-qchep-ph0 citations
47
Standard Model Effective Field Theory and Oscillons
Z. Drogosz🇵🇱 · E.I. Sfakianakis🇺🇸 · K. Slawinska🇵🇱 · A. Wereszczynski🇵🇱
We show that the inclusion of a dimension-six operator in the Higgs potential has a dramatic impact on the stability of oscillons in the $S U (2)$ bosonic sector of the Standard Model, extending their lifetime by orders of magnitude. This happens for the physical value of the ratio between the Higgs and W boson masses, $m_{H} / m_{W} = 1.556$ and for the dimension-six operator $O_{6} = (Φ^{†} Φ)^{3}$ whose coupling constant is below the current upper bound.
↳ hep-thhep-phnlin.PS0 citations
48
The Pull of Stasis: A Study of the Dynamics of the Thermal Stasis Attractor
Jonah Barber🇺🇸 · Keith R. Dienes🇺🇸 · Brooks Thomas🇺🇸
Cosmological stasis, a surprising phenomenon in which the abundances of different energy components in the universe with different equations of state remain constant despite cosmological expansion, has been a focus of recent attention. This behavior emerges as the consequence of an attractor that governs the dynamics of the corresponding cosmological system and pulls it towards stasis even if the system is not initially in this state. However, while some systems actually reach stasis in finite time, it is also possible for such systems to spend considerable time under the influence of this attractor, continually heading towards stasis without ever quite reaching it. This too represents behavior that is entirely unexpected within standard cosmological scenarios. In this paper, we present an explicit model which realizes both of these behaviors in a thermal context while satisfying all relevant phenomenological and cosmological constraints. Within this model, we then examine how the attractor influences the cosmological dynamics and explore the potential consequences for the early universe.
↳ astro-ph.COhep-ph0 citations
49
ALAverse: A falsifiable anthropic model from the string landscape
Zhiqi Huang🇨🇳
We combine the axiverse with a negative cosmological constant $Λ$ , both originating from the string landscape, and apply an observation-time-weighted anthropic argument. Adopting a uniform prior on $Λ$ and a typical string-motivated axion decay constant comparable to the reduced Planck scale, this framework predicts a $\sim 40%$ probability of observing $0.1 < Ω_{m} < 0.9$ , thereby naturally resolving the long-standing fine-tuning and coincidence problems of dark energy. Unlike many scalar-field dark energy models, the anthropic Lambda-axion universe (ALAverse) statistically disfavors slow-roll dynamics, as slow-roll requires fine-tuning of the initial field displacement. Moreover, the negative cosmological constant renders fast-roll scenarios anthropically unfavorable, since they typically yield only a very brief observational window with positive dark energy density. Having ruled out both extremes, the ALAverse characteristically predicts a moderate-roll dynamics. We derive a two-parameter parametrization in terms of $δ_{Ω}$ and $∣ ε_{s} ∣$ that covers ALAverse solutions as well as a broad class of canonical and phantom field models. Current observational data yield $δ_{Ω} = - 0.0498 \pm 0.0186$ , corresponding to a $2.7 σ$ rejection of $Λ$ CDM ( $δ_{Ω} = 0$ ) and phantom models ( $δ_{Ω} > 0$ ). The data also show a mild preference for the ALAverse over slow-roll quintessence, a trend that can be conclusively tested with future high-precision measurements of the Hubble diagram.
↳ astro-ph.COgr-qchep-phhep-th0 citations
50
Study the Longitudinal Entropy Deposition using d+Au Collision
Zhu Meng🇨🇳 · Weiyao Ke🇨🇳 · Long-Gang Pang🇨🇳
Relativistic hydrodynamics successfully describes bulk observables in symmetric heavy-ion collisions, but struggles to reproduce charged-particle rapidity distributions in asymmetric systems such as d+Au collisions. To address this challenge, we introduce two key improvements to the initial-state modeling: sampling deuteron configurations from an ab initio wavefunction, and developing a new longitudinal entropy deposition model that incorporates a transverse entropy deposition coefficient $β$ and a rapidity loss term scaling with the number of binary collisions $n_{BC}$ . Using the (3+1)-dimensional viscous hydrodynamic model CLVisc coupled with the SMASH afterburner, we simulate d+Au collisions at $s_{NN} = 200$ GeV and successfully reproduce the experimental charged-particle pseudorapidity distributions across five centrality classes with $β = 0.35$ , as well as the transverse momentum spectra and anisotropic flow $v_{n}$ . The entropy deposition coefficient $β$ and the $n_{BC}$ -dependent rapidity loss are found to play crucial roles in achieving this agreement. Furthermore, this longitudinal entropy deposition framework demonstrates excellent universality, as validated in p+Au, $^{3}$ He+Au, and Au+Au collisions. Our entropy deposition mechanism could be widely applied to recent light-nucleus collisions such as O+O, Ne+Ne, and asymmetric systems like Pb+Ne at LHC energies, thereby better constraining the nuclear structure of light nuclei through an improved longitudinal description.
↳ nucl-thhep-ph0 citations
51
Dynamical Quarks in the Ensemble of Center Vortices with Monopole Defects: Color Confinement Beyond External Probes
Luis E. Oxman🇧🇷
We consider the interaction of dynamical quarks with the ensemble of oriented and nonoriented center vortices proposed to describe flux-tube formation between quark probes in pure Yang-Mills theory. The quark sector is described in terms of bosonized color currents. Within this fluid-like framework, the infrared vortex--monopole condensate restricts finite-energy configurations to be color neutral. Furthermore, neutral distributions of constituent color densities embedded in the condensate generate frustrated regions, providing a mechanism for their localization into finite-size configurations. The resulting picture is consistent with lattice evidence indicating that center vortices play a central role in shaping the hadron spectrum.
↳ hep-thhep-lathep-ph0 citations
52
Exploring the Effects of Color Reconnection on Net-Charge Fluctuations in $pp$ Collisions at $s = 2.76 TeV$ using PYTHIA Monash
Dibakar Dhar · Tumpa Biswas🇮🇳 · Zubayer Ahammed🇮🇳 · Prabir Kumar Haldar🇮🇳
This work explores the effects of various color reconnection (CR) configurations on the net charge fluctuations of charged particles generated in $pp$ collisions at a center-of-mass energy of $s$ = 2.76 TeV, simulated with the PYTHIA Monash using the variable $ν_{(+, -, dyn)}$ . The results are compared with experimental data from ALICE, revealing that the current PYTHIA simulation settings overestimate the net charge fluctuations relative to the experimental observations. Furthermore, $ν_{(+, -, dyn)}$ exhibits a clear dependence on the MPICR range parameter, where increasing the range leads to more negative $ν_{(+, -, dyn)}$ values, suggesting the geometric extent of CR directly modulates the strength of local charge correlation. To ensure these effects are not a trivial consequence of particle density, a comparison with a retuned NoCR baseline at fixed multiplicity was performed. This analysis confirms that CR induces a genuine dynamical shift in fluctuations that persists independently of the average charged-particle density. The study also shows that the net charge and net pion channels display the strongest suppression in $⟨ N_{ch} ⟩ ν_{(+-, dyn)}$ compared to the net kaon and net proton channels. Overall, the study offers a useful benchmark against experimental results and sheds light on the underlying dynamics of the PYTHIA Monash.
↳ nucl-exhep-ph0 citations
53
Updated 1.1% Precision Values of the Hubble Constant with Corrected Pantheon+ and Dark Energy Survey (DES)-DOVEKIE Type Ia Supernovae
Shouvik Roy Choudhury🇹🇼
We update the Hubble constant measurement with corrected Pantheon+ and DES-DOVEKIE supernovae. The use of DES-DOVEKIE here is the first application of DES-DOVEKIE to a distance-ladder $H_{0}$ determination. Recent reanalyses of supernova datasets have put Pantheon+, DES-DOVEKIE, and Union3.1 samples on the same footing with regard to the evidence of dynamical dark energy ( $3.2$ -- $3.4 σ$ ), and thus an update on the Hubble constant is the next logical step. The $H_{0}$ Distance Network (H0DN) baseline is $73.499 \pm 0.809$ km s $^{- 1}$ Mpc $^{- 1}$ , a $7.1 σ$ tension with the cosmic microwave background (CMB) determination in a $Λ$ cold-dark-matter ( $Λ$ CDM) cosmology, $H_{0}^{CMB, ΛCDM} = 67.24 \pm 0.35$ km s $^{- 1}$ Mpc $^{- 1}$ . A revised host-mass correction applied to the older Pantheon+ changes 114 of the total 1701 apparent-magnitude rows. The calibrator supernovae are not affected, but 52 of the 277 Hubble-flow rows are. Applying only these magnitude corrections, with the H0DN covariance, redshifts, and velocities unchanged, gives $H_{0} = 73.264 \pm 0.806$ km s $^{- 1}$ Mpc $^{- 1}$ and a $6.85 σ$ Hubble tension. This is our main baseline result and the update for the astrophysics community. Alternatively, replacing the complete Hubble-flow treatment with the corrected Pantheon+ data gives $73.139 \pm 0.791$ km s $^{- 1}$ Mpc $^{- 1}$ and $6.82 σ$ . For DES-DOVEKIE, 220 supernovae span $0.025 \leq z_{HD} \leq 0.151$ in Hubble-diagram redshift, and 196 of them overlap with corrected Pantheon+. These overlaps determine the offset used to place the public DES-DOVEKIE distance moduli on the H0DN apparent-magnitude scale. Holding this offset fixed gives $H_{0} = 73.267 \pm 0.828$ km s $^{- 1}$ Mpc $^{- 1}$ and a $6.70 σ$ tension. Extending to $z_{HD} ≃ 0.3$ raises $H_{0}$ . However, both rises are smaller than the H0DN uncertainty. Neither update resolves the Hubble tension. (abridged)
↳ astro-ph.COhep-ph3 citations
54
Dark Matter Searches with Sodium Iodide Detectors
Maria Martinez🇪🇸 · Reina H. Maruyama🇺🇸 · Maria Luisa Sarsa🇪🇸
The search for the identity of dark matter remains one of the most intriguing challenges in physics today, driving innovative advances in experiment and theory. Thallium-doped sodium iodide (NaI) detectors have played a pivotal role in this context. This review outlines the scientific landscape surrounding NaI detectors, emphasizing their role in the broader context of dark matter research. We begin with a brief description of characteristics that make these detectors well-suited for dark matter detection. We then provide a historical overview and explore the results from the DAMA/NaI and DAMA/LIBRA experiments, which have reported annual modulation signals consistent with dark matter interactions--a signal that to date no other experiment has replicated. We discuss recent results from NaI-based experiments launched, in part, to resolve this tantalizing anomaly. We conclude with a summary of the status and prospects for current and future NaI-based dark matter searches.
↳ hep-exastro-ph.IMhep-ph0 citations
55
First constraints on the nonperturbative gluon Collins-Soper kernel
Artur Avkhadiev🇺🇸 · Yang Fu🇺🇸 · Phiala E. Shanahan🇺🇸 · Michael L. Wagman🇺🇸 · Yong Zhao🇺🇸
The gluon Collins-Soper kernel, which encodes the rapidity evolution of transverse-momentum-dependent gluon distributions, is constrained for the first time in the nonperturbative regime, for transverse momentum scales $q_{T} \in [300 MeV, 1.3 GeV]$ . The constraints are determined in lattice QCD at a close-to-physical pion mass $M_{π} = 172 (3) MeV$ , a single lattice spacing $a = 0.15 fm$ , and next-to-next-to-leading logarithmic matching in Large-Momentum Effective Theory. These results represent the first step toward a controlled determination of the gluon Collins-Soper kernel in QCD, with eventual phenomenological import and relevance to present and future experiments sensitive to the gluon structure of hadronic matter.
↳ hep-lathep-phnucl-th1 citation
56
Analytic decomposition of two-body electroweak processes with left-hand cuts
André Baião-Raposo🇩🇪 · Raúl A. Briceño🇺🇸 · Nicolas Lang🇪🇸 · Felipe G. Ortega-Gama🇺🇸 · Bianca Pol🇺🇸
We derive an on-shell representation for electroweak $2 + J \to 2$ transition amplitudes involving two hadrons in both the initial and final state for systems where there are left-hand singularities generated by light-particle exchange, e.g. one-pion exchange. The derivation treats the insertion of the electroweak current perturbatively, keeping only the leading-order contribution in the external field, while the hadronic interactions are treated to all orders, including one-particle exchange effects. We find that, in such processes, the amplitude can have logarithmic singularities, as well as one-particle pole singularities, due to these exchanges. We isolate those contributions, as well as previously identified triangle singularities. The result is expressed in terms of the purely hadronic amplitude, exchange-current kernels, triangle functions, and a class of short-distance transition functions that are real and smooth below unaccounted-for thresholds. While we consider only transitions with spinless particles, this work is an important step toward constraining form factors of systems involving nucleons or vector mesons in the heavy quark sector, where the one-pion-exchange singularity is quite close to threshold.
↳ hep-lathep-phnucl-th1 citation
57
Two-neutrino double-weak decays of $^{126}$ Xe and $^{134}$ Xe from different many-body methods
C. Brase🇩🇪 · L. Jokiniemi🇨🇦 · E. Kauppinen · B. Romeo🇺🇸 · J. Kotila🇫🇮 · J. Menéndez🇪🇸 · A. Schwenk🇩🇪
We calculate the nuclear matrix elements and corresponding half-lives for the two-neutrino double-electron capture of $^{126}$ Xe and the two-neutrino double-beta decay of $^{134}$ Xe. We use different many-body methods: the proton-neutron quasiparticle random-phase approximation, the nuclear shell model, the microscopic interacting boson model, and an effective field theory for heavy nuclei. For both nuclei, all our half-life predictions are generally consistent with each other when including theoretical uncertainties for each method. Interestingly, for all calculations the lower range of the predicted $^{134}$ Xe half-life is shorter than $T_{1/2}^{2 ν} \approx 2 \times 1 0^{24}$ \,y, which may be within the reach of next-generation experiments. For $^{126}$ Xe, our results typically predict one order of magnitude longer half-lives than those for $^{134}$ Xe.
↳ nucl-thhep-phnucl-ex0 citations
58
Measuring Cosmic Neutrino Masses Independently of Dark Energy
Frank J. Qu🇺🇸 · Fei Ge🇨🇳 · Hanyue Wang🇨🇳 · Emmanuel Schaan🇺🇸 · W.L. Kimmy Wu · Alexander Friedland🇺🇸 · Blake D. Sherwin🇬🇧
Neutrino oscillations establish that neutrinos are massive, providing the only laboratory detection of physics beyond the Standard Model. Direct kinematic experiments bound the electron-neutrino mass to $m_{ν_{e}} < 0.45$ eV (KATRIN, 90% CL), implying $\sum m_{ν} ≲ 1.3$ eV. Conversely, cosmology within $Λ$ CDM is highly constraining: Planck CMB, CMB lensing, and DESI DR2 BAO yield $\sum m_{ν} < 0.056$ eV (95% CL), in 2-3 $σ$ tension with the inverted-ordering floor (0.10 eV). However, this bound relies on $Λ$ CDM, while data hint at an evolving dark energy. To determine the model dependence of cosmic neutrino mass bounds, we deconstruct each probe's sensitivity to late-time physics and pursue two robust routes to a $\sum m_{ν}$ bound: (i) The existing dark-energy-marginalized route, retaining all data and marginalizing over $(w_{0}, w_{a})$ , is shown to also be immune to flexible binned and cubic $w (a)$ histories, yielding $\sum m_{ν} < 0.152$ eV, sharpening to $σ (\sum m_{ν}) \approx 0.043$ eV with Simons Observatory lensing and Spec-S5 BAO. (ii) A new late-Universe-free route combines primary CMB, marginalizing over acoustic-peak smoothing via $A_{lens}$ , with the reconstructed lensing spectrum $C_{L}^{κκ}$ , removing late-time expansion dependence by construction. This yields $\sum m_{ν} < 0.41$ eV today, tightening to 0.31 eV (Simons Observatory) and 0.28 eV (cosmic-variance limit) across all tested dark-energy models. These relaxed bounds trade statistical power for model independence. Interestingly, they land in the sensitivity range targeted by next-generation laboratory experiments like Project 8 ( $m_{ν_{e}} \sim 0.1$ eV), motivating vital synergies between future cosmological and terrestrial neutrino measurements.
↳ astro-ph.COhep-exhep-ph0 citations

Affiliations

first authorsco-authorsvia INSPIRE