HEP Phenomenology·hep-ph

Tue·Jul 21, 2026Tuesday·July 21, 2026

47 papers—31 primary·16 cross-listed

01
Earth as a transducer for ultralight bosonic dark-matter detection
Saarik Kalia🇺🇸 · Ibrahim A. Sulai🇺🇸
Ultralight bosonic dark matter (UBDM) that couples to electromagnetism can generate an oscillating magnetic-field signal at the Earth's surface. This is referred to as the ``Earth transducer" effect, as the Earth converts UBDM into a detectable magnetic field. Similar DM-induced fields in laboratory experiments typically scale with the size $L$ of the experiment. Because the Earth transducer signal instead scales with the large radius of the Earth, $R$ , it is one of the most powerful direct probes of UBDM with masses $m_{DM} ≲ 1/ R \sim 3 \times 1 0^{- 14} eV$ . It has many other favorable properties, such as high spatial and temporal coherence and robustness to atmospheric modeling. In this review, we derive the Earth transducer effect and its properties for multiple UBDM models, and discuss current and future prospects to detect it.
hep-phastro-ph.COUniverse(2026)·0 citations
02
Transverse Charge Distribution as a Probe of Nucleon Transversity
Wanchen Li🇨🇳 · Xiaohui Liu🇨🇳 · Ding Yu Shao🇨🇳
We introduce the transverse charge distribution as a spin-sensitive charge-flow probe for fragmentation and nucleon tomography. By measuring the angular distribution of net electric charge around a fragmenting quark, this observable relies entirely on the tracking of charged-particle directions and charge signs, strictly bypassing the need for calorimetric energy measurements. At leading twist, the distribution decomposes into an unpolarized charge monopole and a chiral-odd transverse charge dipole. We derive the operator product expansion of these distributions onto charge-weighted collinear moments: a charge monopole and a charge dipole governed by the Collins effect and couples directly to transversity. Applying this formalism to transversely polarized $p^{↑} p$ collisions at RHIC, we show that charge weighting suppresses the unpolarized monopole background and causes the spin-dependent dipoles from oppositely charged hadrons to add coherently. This coherence strongly enhances the resulting azimuthal asymmetries, establishing a theoretically clean and experimentally precise track-only avenue for extracting transversity.
hep-phhep-exnucl-exnucl-th1 citation
03
Attractodynamics in 0+1D
Jean F. Du Plessis🇺🇸 · Bruno Scheihing-Hitschfeld🇺🇸 · Rachel Steinhorst🇺🇸
Hydrodynamics is a macroscopic theory of long-wavelength dynamics around local thermal equilibrium. We develop attractodynamics, the analogous construction around a far-from-equilibrium attractor. Dynamics near a far-from-equilibrium attractor retains some non-hydrodynamic microscopic information, which attractodynamics systematically organizes. We move towards this general structure by starting in 0+1D, and consider a model for which an anisotropic far-from-equilibrium attractor solution is exactly known. This setting provides a clean benchmark in which the ideal attractodynamic equations and a leading transient residual extension can be compared directly with the full kinetic evolution. The resulting hierarchy gives an improvable description of near-attractor dynamics: the ideal theory captures evolution close to the attracting manifold, while retaining the leading off-attractor moments extends the regime of agreement until the finite truncation breaks down. This example identifies the ingredients needed for local 3+1D attractodynamics and for macroscopic attractodynamic theories not derived from an underlying kinetic description.
hep-phhep-thnucl-th1 citation
04
Particle productions during collisions of highly boosted bubble walls
Haipeng An🇨🇳 · Hongyi Jiang🇨🇳
We investigate the production of particles much heavier than the characteristic scale of a cosmological first-order phase transition through collisions of highly boosted bubble walls. Using the scalar order-parameter field, we derive the ultraviolet behavior of its Fourier-space profile for both elastic and inelastic collisions. In the regime $χ \equiv ω^{2} - k^{2} ≫ M_{h}^{2}$ , we find the universal result $ϕ ~ (χ) = - 2 V^{'} (2 v_{ϕ}) χ^{- 2} + O (χ^{- 3}),$ implying that the spectral density scales as $F (χ) \propto [V^{'} (2 v_{ϕ})]^{2} χ^{- 4}$ . Thus, heavy-particle production is localized near the instant of collision and, at leading order, depends on the scalar potential only through $V^{'} (2 v_{ϕ})$ . We verify this behavior using high-precision numerical solutions of the trapping equation, carefully suppressing spectral leakage from the finite integration domain, and obtain agreement over a broad ultraviolet range. We then derive analytical production rates for general heavy-particle thresholds and for fermion pairs, together with their cosmological number density and yield. Finally, we extend the analysis to $(3 + 1)$ dimensions and incorporate the finite bubble radius, finding an order-one suppression relative to the parallel-wall approximation. Our results revise the ultraviolet scaling used in previous treatments and have direct implications for superheavy dark-matter production and baryogenesis from bubble collisions.
hep-phastro-ph.CO4 citations
05
Long-Lived Dark Hadrons at the Electron-Ion Collider
Hooman Davoudiasl🇺🇸 · Hongkai Liu🇺🇸 · Ethan T. Neil🇺🇸
We study a dark non-Abelian gauge sector with GeV-scale confinement. The dark sector is assumed to couple only feebly to the Standard Model, while its low-energy spectrum may contain long-lived flavor-diagonal dark pions. Signals of these states are particularly well suited to the Electron-Ion Collider (EIC), where the absence of a hard trigger requirement and the capability to record soft final-state particles offer a complementary probe of dark hadronization dynamics. We present a benchmark portal construction, discuss the mixing between an axion-like mediator and dark pions, and identify the resulting displaced-decay signature.
hep-phhep-exnucl-ex0 citations
06
Light-front diagnostics in the 't Hooft model: II. Boundary cancellations, ERBL spectral sums, and analyticity of the EMT form factor
Arkadiy I. Syamtomov🇺🇦
A diagonal light-front overlap contains near-forward energy-momentum-tensor (EMT) information but is not itself a local matrix element. In the large- $N_{c}$ 't Hooft model we complete the second GPD moment with its ERBL contribution and follow how the two support regions combine. Boundary exponents generate fractional powers and, at $β = 1/2$ , resonant logarithms in the separate terms. We show that these structures cancel, including the interference of the leading and next indicial families. At the resonance, cancellation of the double and single logarithms also yields an inverse-mass-squared residue sum rule; above it, the two regions combine into a finite fourth-order coefficient. The complete EMT form factor is therefore analytic through curvature order. The ERBL sector leaves the slope unchanged but is essential for curvature and higher derivatives. We extract stable canonical and heavy curvatures, estimates with systematic envelopes for the second and third light excitations, and the longitudinal trace radius. The intermediate-state decomposition further shows how constituent mass and excitation redistribute pole strength and generate removable poles and interference zeros.
hep-phhep-th0 citations
07
Exact constraints on family-separated seesaw relations and their phenomenological consequences
Jianlong Lu🇸🇬
Working at tree level and at a common renormalization scale, we examine the family-separated seesaw ansatz of Z.-z.~Xing, arXiv:2605.27049v2. For a fixed light-heavy pairing, imposing $m_{i} U_{α i} U_{β i} + M_{i} R_{α i} R_{β i} = 0$ together with $U U^{†} + R R^{†} = 1$ yields the general exact solution $U = V D^{- 1/2}$ and $R = iV E diag (r_{i} / (1 + r_{i}))$ , where $r_{i} = m_{i} / M_{i}$ , $D = diag (1 + r_{i})$ , $V$ is unitary, and $E = diag (η_{i})$ with $η_{i} = \pm 1$ . Consequently, $U^{†} U$ and $R^{†} R$ are diagonal, and distinct columns are exactly orthogonal. An exact unitary completion gives, in a convenient sterile basis, $M_{R} = D_{N} - D_{ν}$ and $Y_{ν} = (i / v) V E (D_{ν} D_{N})^{1/2}$ , so that $Y_{ν}^{†} Y_{ν} = D_{ν} D_{N} / v^{2}$ is diagonal. In the canonical domain $M_{i} > m_{i}$ , the singlet masses relevant to the unbroken-phase decay description are $M_{i} = M_{i} - m_{i} > 0$ , distinct from the broken-phase heavy eigenvalues $M_{i}$ . Hence, at the scale of exact alignment, all standard unflavored and flavored nonresonant one-loop decay asymmetries vanish in the nondegenerate perturbative regime. For $m_{i} = 0$ , the paired Yukawa column and decay width vanish instead. The flavor-summed rephasing-invariant combination used in the proposed asymmetry also cancels identically, although individual CP-odd invariants may remain nonzero. Thus the proposed correlation between low-energy CP violation and these decay asymmetries does not follow from exact family separation. This result does not address radiative misalignment, resonant or coherent dynamics, or thermal and higher-loop sources. We also correct the proposed heavy-mass reconstruction formulas and clarify the implications for neutrinoless double-beta decay, Yukawa scaling, parameter counting, and light-heavy mass orderings.
hep-ph0 citations
08
The semileptonic decays of $B_{Q_{1} Q_{2}} (\frac{1}{2}^{+}) \to B_{Q_{1}}^{*} (\frac{3}{2}^{+})$ in QCD sum rules
Guo-Liang Yu🇨🇳 · Zhi-Gang Wang🇨🇳 · Jie Lu🇨🇳 · Bin Wu🇨🇳 · Peng Yang🇨🇳 · Ze Zhou🇨🇳
In the framework of QCD sum rules, we systematically analyze the weak transition process $B_{Q_{1} Q_{2}} (\frac{1}{2}^{+}) \to B_{Q_{1}}^{*} (\frac{3}{2}^{+})$ . When doing the operator product expansion in the QCD side, we consider the contributions of perturbative part and vacuum condensate terms up to dimension 6. In the phenomenological side, we eliminate the interferences of the low spin states and negative parity states by employing 16 different dirac structures. As an application, these form factors are finally used to analyze the semileptonic decays of $B_{Q_{1} Q_{2}} (\frac{1}{2}^{+}) \to B_{Q_{1}}^{*} (\frac{3}{2}^{+}) l ν$ , where these decays are driven by the transition processes $c \to d / s + l^{+} + ν_{l}$ and $b \to u + l^{-} + ν_{l}$ . The predicted physical quantities include not only the partial widths, ratios of $Γ_{L} / Γ_{T}$ and the branching fractions, but also some observables such as the forward-backward asymmetry parameter $A_{F B}^{l}$ of lepton, the $P_{z}^{F}$ component of the polarization vector for daughter baryon and the longitudinal polarization of the lepton $P_{z}^{l}$ . We hope all of these theoretical predictions about the weak decays will be helpful for studying the properties of doubly heavy baryons in experiments in the future.
hep-ph0 citations
09
Could $Λ ˉ_{c}$ and $Λ_{c}$ form bound hadronic molecule with explicit $P - w a v e$ ?
Xiu-Wu Wang🇨🇳 · Zhi-Gang Wang🇨🇳
In this article, the explicit $P - w a v e$ of the $Λ ˉ_{c} Λ_{c}$ dibaryon states with the $J^{P C} = 0^{-\pm}$ and $1^{-\pm}$ are studied via twelve interpolated currents. Results show that the positive and negative charge conjugations for the studied states do not have too much difference, the contribution of the gluon from covariant derivative of the current with $P - w a v e$ could be neglected. The numerical results of the masses of the $P - w a v e$ $Λ ˉ_{c} Λ_{c}$ are high above the threshold of the two $Λ ˉ_{c}$ and $Λ_{c}$ baryon constituents, $Λ ˉ_{c}$ and $Λ_{c}$ are unlikely to form the bound molecules with explicit $P - w a v e$ . Pole residues of the related states are also calculated.
hep-ph0 citations
10
The muon collider: expected physics, technological solutions, and the prospect of a 21 km ring at the UNK site
L. V. Dudko🇷🇺
A multi-TeV muon collider has emerged as one of the most compelling options for the post-LHC energy frontier. Because the muon is an elementary particle that radiates $\sim 1 0^{9}$ times less synchrotron power than an electron of the same energy, a circular muon collider delivers the full beam energy to the hard collision in a remarkably compact ring, combining the energy reach of a $100$ ~TeV-class proton machine with the clean final states of a lepton collider. This review summarizes the expected physics results -- Higgs couplings and self-couplings, electroweak and vector-boson-fusion processes, the top quark, a broad beyond-the-Standard Model programme, and a near-complete closure of the thermal window for electroweak WIMP dark matter -- and the status of the enabling technologies, emphasizing for each challenge how it is being solved and where the solution is documented: muon production, ionization cooling (demonstrated in the transverse plane by MICE), rapid acceleration, high-field HTS magnets, the machine-detector interface, and the neutrino-flux constraint. Building on this foundation, this review examines the prospect of housing a muon collider in the existing 21~km UNK tunnel near Protvino, where the magnetic-rigidity relation maps realistic arc fields onto a centre-of-mass energy of order $10$ - $20$ TeV -- reaching the IMCC 10~TeV reference with conventional dipoles and exceeding it with high-temperature-superconductor dipoles. It closes with a discussion of non-collider applications of the intense muon beams such a facility would develop -- muon-catalyzed fusion, muography, muonic-atom isotopic analysis, and muon spin spectroscopy -- several with a long tradition in the Russian physics institutes.
hep-ph0 citations
11
Geometric Scaling and the Odderon
Michal Praszalowicz🇵🇱
Based on geometric scaling of elastic $pp$ and possibly $p p ˉ$ cross-sections, we derive simple formulae for the complex crossing-even and crossing-odd scattering amplitudes in terms of two interaction radii: $R (s)$ and $Q (s)$ , respectively. Employing the COMPETE parametrization of the total cross-sections, we reproduce $ρ^{pp}$ and $ρ^{p p ˉ}$ parameters with high accuracy, however we miss the 13~TeV TOTEM and ATLAS points. We show that a slight modification of the $p p ˉ$ total cross-section corresponding to the Odderon, allows to accommodate $ρ^{pp}$ 13~TeV data.
hep-ph0 citations
12
Imprints of Higgs-portal fermionic dark matter on neutron-star tidal deformability and the mass-radius slope
Monmoy Molla🇮🇳 · Mehedi Kalam🇮🇳 · Tuhin Malik🇵🇹
We investigate the structure of neutron stars (NSs) admixed with fermionic dark matter (DM) using three density-dependent relativistic mean-field (DDRMF) functionals (DDME, DDB, and GDFM) for $β$ -equilibrated nucleonic matter. Modeling DM as the lightest neutralino interacting via Higgs exchange, we treat the DM Fermi momentum $k_{F}^{DM}$ as a control parameter in the range $0.02$ - $0.06$ GeV. We solve the coupled mean-field and Tolman-Oppenheimer-Volkoff equations to obtain the mass-radius relation, maximum mass $M_{max}$ , radial sound speed profile $c_{s}^{2}$ , and tidal deformability $Λ$ . In all models, DM softens the equation of state, systematically reducing $M_{max}$ , the radius $R_{1.4}$ (at $1.4 M_{⊙}$ ), and the tidal deformability $Λ_{1.4}$ (at $1.4 M_{⊙}$ ) as $k_{F}^{DM}$ increases. Consequently, the $2 M_{⊙}$ pulsar limit and NICER data place a model-dependent upper limit on the DM content, while the GW170817 tidal bound requires a minimal DM content for the stiffest functional. Using a recent Bayesian inference of the DDRMF equation of state as the nucleonic reference band, we evaluate if this DM imprint can be distinguished from nucleonic uncertainties using only measureable quantities. Analyzing the tidal deformability $Λ$ and mass-radius slope $d R / d M$ at fixed mass, we find that $Λ$ is a sharp discriminator: at $1.4 M_{⊙}$ and $k_{F}^{DM} = 0.06$ GeV, the DM-induced reduction of $Λ$ reaches $≃ 8$ times the nucleonic $1 σ$ width (model-independently $7.5$ - $7.8 σ$ ). The DM track leaves the nucleonic $1 σ$ band for $k_{F}^{DM} ≳ 0.03$ - $0.04$ GeV, whereas $d R / d M$ becomes diagnostic only for the heavier ( $1.8$ - $2.0 M_{⊙}$ ) branch.
hep-ph0 citations
13
Neutrino lines and photon continua from cascade dark matter decay
Jun Guo🇨🇳 · Shi-ying Zhao🇨🇳 · Bin Zhu🇨🇳
We investigate the two-body decay of fermionic dark matter, $χ (χ ˉ) \to X + ν (ν ˉ)$ , where the light mediator $X$ subsequently decays into photons. We consider two benchmark models: an axion-like particle with $a \to γ γ$ , and a kinetically mixed dark vector with $A^{'} \to 3 γ$ . This decay topology produces a monochromatic neutrino line from the primary decay together with a broad secondary photon continuum. A key feature of the scenario is that the photon signal depends on the mediator decay length, whereas the neutrino line is produced promptly and is insensitive to the subsequent propagation of $X$ . We derive dark matter lifetime limits from current and projected MeV gamma-ray and neutrino searches, including both Galactic and delayed extragalactic photon contributions. We find that photon constraints generally dominate for short-lived mediators, while neutrino-line searches can become competitive or provide the leading sensitivity in regions where mediator propagation substantially suppresses the photon signal. This conclusion remains stable under conservative extragalactic-only limits and a simplified treatment of Galactic spatial smearing.
hep-ph0 citations
14
Holographic spectral functions of exotic spin-1 mesons
Yan-Qing Zhao🇨🇳 · Zhou-Run Zhu🇨🇳
We develop a general holographic framework for computing thermal spectral functions of exotic spin--1 mesons. A bulk Proca mass encodes the canonical ultraviolet dimension of the interpolating operator, allowing channels with different ultraviolet scaling to be treated within a unified membrane-flow formalism in the zero-spatial-momentum limit. We test this framework in a soft-wall model with a gluon-condensate background for the hybrid $π_{1}$ and tetraquark-like $Z_{c}$ channels. The results show that dissociation temperatures of both channels lie below the phase transition temperatures. Increasing $c$ delays dissociation in both channels, but through different effects: both the vacuum-mass shift and thermal spectral deformation contribute in the $π_{1}$ channel, whereas the latter dominates in the $Z_{c}$ channel. Nevertheless, for the same environment, the $Z_{c}$ resonance dissociates at a lower temperature than the $π_{1}$ resonance.
hep-ph0 citations
15
Detailed study of the dual symmetry of dense quark matter within the effective action formalism
T. G. Khunjua🇬🇪 · K. G. Klimenko🇷🇺 · R. N. Zhokhov🇷🇺
The symmetry properties of the phase diagram of dense quark matter composed of $u$ and $d$ quarks with three colors have been investigated in the framework of massless (3+1)-dimensional Nambu--Jona-Lasinio (NJL) and QCD models. It turns out that in the presence of baryon $μ_{B}$ , isospin $μ_{I}$ , chiral $μ_{5}$ and chiral isospin $μ_{I 5}$ chemical potentials, the Lagrangians of these models are invariant under the so-called dual transformation $D$ . In this paper, it has been shown that the path integration measure of the corresponding partition functions is also invariant under $D$ . Consequently, the entire NJL model (or QCD) thermodynamic potentials are dually symmetric. In particular, it means that in the total $(μ_{B}, μ_{I}, μ_{5}, μ_{I 5})$ -phase portraits of these models the chiral symmetry breaking (CSB) and charged pion condensation (PC) phases are arranged dually conjugate (or symmetrically) to each other. Dual symmetry between CSB and charged PC phases of quark matter is a fundamental property of massless dense QCD; it should be observed in the framework of any approximation to the QCD phase diagram, and have important implications for studies of the phase structure.
hep-phhep-th0 citations
16
Scrutinizing lepton flavor universality and transition form factor correlation from charmed meson semileptonic decay into light strange vector $K^{*}$ meson
Sheng-Bo Wu🇨🇳 · Dong Huang🇨🇳 · Fang-Ping Peng🇨🇳 · Hai-Bing Fu🇨🇳 · Long-Zeng
In this paper, we calculate the transition form factors (TFFs) $A_{1, 2} (q^{2})$ and $V (q^{2})$ of $D_{s}^{+} \to K^{* 0}$ decays by using the QCD light-cone sum rule (QCD LCSR) and constructing a correlation function containing the usual current, in which the twist-2 transverse and longitudinal light-cone distribution amplitudes (LCDAs) $ϕ_{2; K^{* 0}}^{λ} (x, μ_{0})$ with $λ = (⊥, ∥)$ of the $K^{* 0}$ meson constitute the main source of theoretical uncertainty. Based on this, we construct these LCDAs using the light-cone harmonic oscillator model. Subsequently, the TFFs obtained in the large recoil region are $A_{1} (0) = 0.57 9_{- 0.028}^{+ 0.024}$ , $A_{2} (0) = 0.41 4_{- 0.023}^{+ 0.021}$ , and $V (0) = 0.83 0_{- 0.020}^{+ 0.020}$ , and the corresponding ratios are obtained to be $r_{V} = 1.43 3_{- 0.090}^{+ 0.110}$ and $r_{2} = 0.71 5_{- 0.067}^{+ 0.075}$ . Furthermore, we predict the correlation of TFFs and their corresponding ratios. Then, we extrapolate the TFFs over the whole physical $q^{2}$ -region and calculate the decay widths and branching fractions for the semileptonic decays $D_{s}^{+} \to K^{* 0} ℓ^{+} ν_{ℓ}$ . The results are $B (D_{s}^{+} \to K^{* 0} e^{+} ν_{e}) = (2.0 5_{- 0.16}^{+ 0.13}) \times 1 0^{- 3}$ and $B (D_{s}^{+} \to K^{* 0} μ^{+} ν_{μ}) = (1.9 5_{- 0.15}^{+ 0.13}) \times 1 0^{- 3}$ . Meanwhile, we calculated the branching fraction ratio $R_{μ / e}^{K^{* 0}}$ to be $0.95 0_{- 0.002}^{+ 0.004}$ . In addition, we extract values of the CKM matrix element, obtaining $∣ V_{c d} ∣_{(e -Channel)} = 0.22 5_{- 0.005}^{+ 0.005}$ and $∣ V_{c d} ∣_{(μ -Channel)} = 0.22 7_{- 0.004}^{+ 0.011}$ . Finally, we calculated the forward-backward asymmetry parameters for the $D_{s}^{+} \to K^{* 0} ℓ^{+} ν_{ℓ}$ decay.
hep-ph0 citations
17
Breaking the Democratic Limit in the Generalized Friedberg-Lee Model: Implications for Neutrino Masses and Mixing
N. Razzaghi🇮🇷
We investigate a generalized Friedberg--Lee (FL) framework for neutrino masses, focusing on the singular parameter space at Point D ( $α = β = - 1/3$ ). At this limit, the neutrino mass matrix exhibits a democratic texture governed by the $S_{3}$ permutation symmetry. Although theoretically profound, the exact democratic limit is phenomenologically excluded as it predicts a degenerate mass spectrum and a vanishing reactor angle ( $θ_{13} = 0$ ). To reconcile this high-symmetry limit with experimental observations, we introduce a minimal and systematic perturbation that preserves the Twisted Friedberg--Lee (TFL) symmetry. This mechanism effectively lifts the mass degeneracy and breaks the magic and $μ$ -- $τ$ symmetries in a controlled manner. Our derivation avoids \textit{ad hoc} parameters, establishing a robust framework that yields a realistic inverted mass hierarchy ( $m_{3} = 0$ ), a non-zero $θ_{13}$ , and intrinsic CP violation. We demonstrate that the model predicts maximal atmospheric mixing and a significant Dirac CP phase. The obtained numerical ranges for the neutrino masses and the Jarlskog invariant show excellent agreement with global fit data, providing a theoretically motivated foundation for neutrino flavor physics within the TFL scheme.
hep-phhep-th0 citations
18
Heavy meson chiral perturbation theory constraints on a charm-coupled GeV-scale QCD axion
Bo-Qiang Lu🇨🇳
The QCD axion with charm-only Peccei-Quinn coupling evades the isospin-violation problem of light-quark models in $χ$ PT. Since $m_{c} > Λ_{QCD}$ , we employ heavy meson chiral perturbation theory (HMChPT) to constrain this GeV-scale axion, including its CP-even radial partner $σ$ and the axion $a$ . In HMChPT, $σ$ enters at leading order with $O (1)$ coupling, while $a$ couples only at $O (1/ m_{c})$ and manifests via axion-pion mixing with $θ_{aπ} ≃ f_{π} / f_{a} \sim 0.04$ . We analyze $D$ -meson masses, $D$ - $D^{*}$ splitting, charmonium, $D$ - $D$ scattering, $B_{s}$ mixing, rare $D$ decays, and the channels $K^{+} \to π^{+} a$ , $B \to K a$ . No fatal HMChPT constraint emerges, unlike the $χ$ PT isospin issue. The strongest bound is from $σ$ -mediated $B_{s}$ - $B ˉ_{s}$ mixing; axion-pion mixing opens testable rare decays, though rates are slightly below current sensitivity.
hep-phgr-qchep-exhep-th1 citation
19
Kapitza Inspired Effective Interaction for the Exotic State X(3872): A Coupled-Channel Potential Model Study
M.Monemzadeh🇮🇷 · N.Tazimi🇮🇷
The X(3872) remains one of the most intriguing exotic hadrons, lying extremely close to the $D^{0} D ˉ^{* 0}$ threshold. We construct an effective potential consisting of Coulomb, linear confinement and a Kapitza-inspired term representing the averaged effect of fast gluonic fluctuations. Numerical solution of the Schrödinger equation shows that this term provides effective attraction in the intermediate-distance region, yielding a ground-state mass of $3871.7 \pm 0.9$ MeV in excellent agreement with experiment. Coupled-channel analysis indicates a dominant molecular component ( $\sim 65% - 72%$ ) with a significant compact tetraquark core ( $\sim 28% - 35%$ ). We also present predictions for low-lying excited states. The model offers a physically motivated mechanism for threshold tuning.
hep-ph0 citations
20
Relative enhancement of low-mass vector-boson exchange in higher waves matrix elements: parity non-conservation in hydrogen
V. A. Dzuba🇦🇺 · V. V. Flambaum🇦🇺 · G. K. Vong🇦🇺
Models of unification predict additional $Z^{'}$ boson, which contributes to parity non-conservation (PNC) in atoms. If $Z^{'}$ boson is light, ratio of $Z^{'}$ boson contribution to the Standard Model $Z$ boson contribution to atomic PNC increases with decreasing nuclear charge $Z$ faster than $1/ Z^{2}$ . This motivated our previous study of PNC in hydrogen and deuterium proportional to the weak interaction matrix elements $< s ∣ W ∣ p >$ . An enormous additional relative enhancement appears in the matrix elements between higher waves, such as $< p_{1/2, 3/2} ∣ W ∣ d_{3/2, 5/2} >$ , since $p_{3/2}$ and $d_{3/2, 5/2}$ wave functions vanish at $r \to 0$ , suppressing matrix elements of the contact $Z$ boson mediated contact electron-nucleus interaction. Measurements of $< p_{1/2, 3/2} ∣ W ∣ d_{3/2, 5/2} >$ will simplify disentanglement of the $Z^{'}$ contribution from the Standard Model background.
hep-phphysics.atom-ph0 citations
21
Heavy quark mass dependence of the $Λ_{Q}$ light-cone distribution amplitude in QCD
Yu-Ji Shi🇨🇳 · Ji Xu🇨🇳 · Shuai Zhao🇨🇳
We study the heavy quark mass dependence of the leading-twist light-cone distribution amplitude (LCDA) of the $Λ_{Q}$ baryon in QCD. Starting from the factorization formula that relates the QCD LCDA to the boosted heavy-quark effective theory (bHQET) LCDA, we derive a first-order partial differential equation governing this mass dependence in the peak region. The equation is solved analytically, and the explicit factor connecting LCDAs at different heavy quark masses is presented. We further incorporate Borel-resummed perturbative corrections from a renormalon model into the factorization. The impact of these renormalon corrections on the mass dependence is studied, and a numerical analysis using a simple LCDA model is performed to illustrate the behavior and to assess the uncertainties arising from the corrections, thereby providing a numerical estimate of the associated power corrections to the mass dependence. Our results provide an essential tool for extrapolating lattice QCD calculations of heavy-baryon LCDAs from smaller simulated masses to the physical bottom quark mass.
hep-phhep-lat1 citation
22
Analysis of the hidden-charm pentaquark candidates in the $J / ψ Σ^{*}$ mass spectrum via the QCD sum rules
Zhi-Gang Wang🇨🇳 · Yang Liu🇨🇳
In this work, we study the diquark-diquark-antiquark type $uu sc c ˉ$ pentaquark states in the light-flavor $10$ representation via the QCD sum rules in details. We exhaust the lowest five-quark configurations and obtain the spectroscopy of the $uu sc c ˉ$ pentaquark states with the quantum numbers $I J^{P} = 1 \frac{1}{2}^{-}$ , $1 \frac{3}{2}^{-}$ , $1 \frac{5}{2}^{-}$ , and suggest to investigate them in the decay chain $Σ_{b}^{+} \to P_{cs}^{+} ϕ \to J / ψ Σ^{*+} ϕ$ experimentally.
hep-ph0 citations
23
Vector mesons leading-twist longitudinal distribution amplitudes and related semi-leptonic decays within QCD sum rules
Wan-Bing Luo🇨🇳 · Ru-Meng Pan🇨🇳 · Ya-Xiong Wang🇨🇳 · Tao Zhong🇨🇳
In this work, we focus on the light vector meson leading-twist longitudinal distribution amplitudes (DAs) $ϕ_{2; V}^{∥} (x, μ)$ with $V = ρ, K^{*}, ϕ$ . In order to obtain their accurate behaviors, a new scheme of QCD sum rule research with respect to DA suggested in 2021 by us is adopted. With an improved sum rule formula, the $ξ$ -moments $⟨ ξ^{n} ⟩_{2; V}^{∥}$ up to tenth order are calculated. In which, $⟨ ξ^{2} ⟩_{2; ρ}^{∥} = 0.22 5_{- 0.012}^{+ 0.013}$ , $⟨ ξ^{1} ⟩_{2; K^{*}}^{∥} = - 0.022 8_{- 0.0040}^{+ 0.0042}$ , $⟨ ξ^{2} ⟩_{2; K^{*}}^{∥} = 0.21 7_{- 0.007}^{+ 0.007}$ , $⟨ ξ^{2} ⟩_{2; ϕ}^{∥} = 0.20 9_{- 0.020}^{+ 0.020}$ , and the corresponding Gegenbauer moments $a_{2; ρ}^{2; ∥} = 0.07 4_{- 0.036}^{+ 0.039}$ , $a_{2; K^{*}}^{1; ∥} = - 0.03 8_{- 0.007}^{+ 0.007}$ , $a_{2; K^{*}}^{2; ∥} = 0.05 0_{- 0.019}^{+ 0.020}$ , $a_{2; ϕ}^{2; ∥} = 0.02 7_{- 0.058}^{+ 0.058}$ at the scale $μ = 1 GeV$ , respectively. By fitting those $⟨ ξ^{n} ⟩_{2; V}^{∥} (n = 1, 2, \dots, 10)$ with the least squares method, the behaviors of leading-twist longitudinal DAs for $ρ, K^{*}, ϕ$ are determined. Further, we recalculate the transition form factors and branching ratio of the $D \to (ρ, K^{*})$ , $D_{s} \to ϕ$ semi-leptonic decay processes.
hep-ph0 citations
24
A Gauge Model for Quasi-Dirac Neutrinos
Zhao-Xing Fan🇨🇳 · Chun Liu🇨🇳
In a model with $L_{μ} - L_{τ}$ Abelian gauge symmetry, anomaly-free chiral fermions, which are Standard Model singlets, are introduced as the origin of right-handed neutrinos. This $U (1)$ symmetry keeps the right-handed neutrinos Majorana massless. Tiny nonvanishing Dirac masses of neutrinos are due to higher-dimensional operators with natural coupling constants. After gauge symmetry breaking, a quasi-Dirac neutrino scenario naturally appears, and realistic neutrino physics can be produced. Phenomenological and cosmological aspects of the model are discussed.
hep-ph0 citations
25
Quantum numbers of excited $Ξ_{c}^{'}$ and $Ω_{c}$ baryons and the $P$ -wave $Σ_{c}$ spectrum
Xuan Luo🇨🇳 · Shu-Wei Zhang🇨🇳 · Hua-Xing Chen🇨🇳 · Hui-Min Yang🇨🇳
Recent precision measurements of excited heavy baryons, combined with systematic theoretical studies, make it possible to resolve the fine structure of their spectra. We calculate the masses and strong-decay properties of the $P$ -wave charmed baryons using QCD sum rules and light-cone sum rules within heavy quark effective theory (HQET). Although seven states are allowed in each flavor sector, we find that only four $Σ_{c}$ , four $Ξ_{c}^{'}$ , and five $Ω_{c}$ states are expected to be experimentally resolvable. The similar mass-splitting patterns of $Ξ_{c} (2882)$ , $Ξ_{c} (2923)$ , $Ξ_{c} (2939)$ , and $Ξ_{c} (2965)$ and of $Ω_{c} (3000)$ , $Ω_{c} (3050)$ , $Ω_{c} (3066)$ , and $Ω_{c} (3090)$ , together with our theoretical results, lead to the successive quantum-number assignments $J^{P} = 1/ 2^{-}, 3/ 2^{-}, 3/ 2^{-}$ , and $5/ 2^{-}$ . We tentatively interpret $Ω_{c} (3119)$ as a predominantly $ρ$ -mode excitation with $J^{P} = 3/ 2^{-}$ . We also predict the masses, widths, and dominant decay modes of four resolvable $P$ -wave $Σ_{c}$ states, which may overlap within the observed $Σ_{c} (2800)$ and $Σ_{c} (2900)$ structures. Precision spectroscopy of the narrow $Ξ_{c}$ and $Ω_{c}$ states thus provides a route to resolving the $P$ -wave $Σ_{c}$ spectrum.
hep-ph2 citations
26
Benchmarking Machine Learning Architectures for ttH Multilepton Signal Sensitivity
Lukáš Viceník🇨🇿 · André Sopczak🇨🇿 · Oleksandr Shekhovtsov🇨🇿
Statistical testing for signal discovery and signal-strength estimation in high-energy physics increasingly relies on machine-learning models trained on simulated data. We present a synthetic dataset for $t t ˉ H$ multilepton signal--background classification and perform a systematic evaluation of machine-learning models ranging from the widely used XGBoost for tabular data to LorentzNet, which processes events with built-in Lorentz symmetry. Existing studies often differ in feature definitions, training procedures, and evaluation metrics, making it difficult to isolate the impact of model architecture on performance. To address this, we apply standardized training and hyperparameter-optimization procedures, construct a controlled hierarchy of feature sets, and perform a comprehensive comparison of the models. In addition to the analysis-driven metric of signal-strength uncertainty, we report the commonly used ROC AUC metric and show that under realistically weighted training, it correlates well with the uncertainty-based ranking of models. We further investigate model performance as a function of input feature set, training-set size, and the choice between channel-specific and unified multi-channel training. Our results establish the superiority of Particle Transformer and LorentzNet within the considered setup. We also identify potential avenues for further improvement, including more expressive architectures, joint training across additional analysis channels, and larger simulated datasets. Although this study focuses on a specific Higgs-boson analysis, we expect the main conclusions to generalize to a broader class of searches and measurements at the LHC and HL-LHC.
hep-ph0 citations
27
The $Υ (n S) \to B_{(c)}$ transition form factors and their applications to semileptonic and nonleptonic weak decays
You-Ya Yang🇨🇳 · Zhi-Qing Zhang🇨🇳 · Zhi-Jie Sun🇮🇷
The semileptonic and nonleptonic decays of the $Υ (n S)$ with $n = 1, 2, 3, 4$ are investigated within the covariant light-front quark model (CLFQM). Using the form factors of the transitions $Υ (n S) \to B_{(c)}$ obtained from the CLFQM, we calculate the branching ratios of the decays $Υ (n S) \to B_{(c)} ℓ ν_{ℓ}$ and $Υ (n S) \to B_{(c)} M$ with $ℓ = e, μ, τ$ and $M$ referring to $π (ρ), K^{(*)}, D^{(*)}, D_{s}^{(*)}$ . One can find that the branching ratios of the decays $Υ (3 S) \to B_{c} ℓ ν_{ℓ}$ are the largest among those of considered semileptonic decays and can amount to $1 0^{- 9}$ ; As to the nonleptonic decays, $Υ (3 S) \to B_{c} ρ$ and $Υ (3 S) \to B_{c} D_{s}^{(*)}$ have the largest branching ratios, which reach up to $1 0^{- 10}$ . Given the identification and detection efficiency of final states, searching for these weak decay modes should be fairly challenging in future experiments. The forward-backward asymmetry $A_{F B}$ and the longitudinal polarization fraction $f_{L}$ are also calculated for those semileptonic decays.
hep-phhep-ex0 citations
28
Wide binaries in ultra-faint dwarf galaxies as a probe of extended dark objects
María Olalla Olea-Romacho🇬🇧
Wide stellar binaries are sensitive dynamical probes of dark matter substructure. We generalize existing point-mass disruption constraints to spherical extended dark objects and apply the resulting framework to the population of wide-binary candidates identified in the ultra-faint dwarf galaxy Bootes I. We derive 95% confidence limits on the dark matter fraction as a function of the perturber mass, the radius enclosing 90% of the mass, and the density profile, considering Navarro-Frenk-White, r^-3/2, and r^-9/4 models. Sufficiently compact objects converge to the point-mass limit, whereas finite size suppresses binary disruption when the perturber becomes comparable to the relevant encounter and binary scales. The constraints remain sensitive to dark matter fractions well below unity over a broad region of the mass-radius plane and extend to objects substantially larger than those accessible to conventional microlensing searches. As an application, we map the r^-3/2 results onto ultracompact minihalos and derive an illustrative constraint on the primordial curvature power spectrum. Ultra-faint-dwarf wide binaries therefore offer a purely gravitational probe of the abundance of extended dark matter objects and of the small-scale primordial curvature power spectrum.
hep-phastro-ph.CO2 citations
29
Correlated comagnetometry for precision measurements
Yossi Rosenzweig🇮🇱 · Yevgeny Kats🇮🇱 · Eli Sarid🇮🇱 · Menachem Givon🇮🇱 · Yonathan Japha🇮🇱 · Ron Folman🇮🇱
Magnetometers are among the most widely used probes in science and technology. Comagnetometers increase sensitivity by self-cancellation of magnetic noise, but only at low frequencies. We suggest a correlated measurement of two alkali species in one cell to cancel the magnetic background also at high frequencies. The inter-species phase difference of the light-matter interaction response function is found to be calibration free and insensitive to common-mode intensity noise. Utilizing a dark-matter signal as a testcase, the method achieves a thirtyfold background suppression, raising the signal-to-noise ratio by an order of magnitude or more, depending on the coupling to the different subatomic particles. We show that the method also provides model differentiation. The higher sensitivity and model differentiation open a path to novel probes for precision measurements in general and exotic fields in particular.
hep-phphysics.atom-ph1 citation
30
HyperIso: A general BSM calculator for flavour observables
T. Reymermier🇫🇷 · N. Fardeau🇫🇷 · F. Mahmoudi🇫🇷
We present HyperIso, a new standalone program for the evaluation of flavour physics observables across a wide variety of Standard Model (SM) and Beyond-the-Standard-Model (BSM) scenarios. The code builds on the physics heritage of SuperIso, but is implemented as a new modular software package with a modern C++ core and multiple user interfaces. In addition to native implementations for established scenarios such as the SM, the general Two-Higgs-Doublet Model (THDM), and supersymmetric models, HyperIso interfaces with the MARTY framework to compute automatically BSM Wilson coefficients at leading order. This design makes it possible to study user-defined BSM models while keeping the observable calculation, uncertainty propagation and statistical interpretation in a common backend. The software provides C++, Python, command-line and graphical interfaces. It supports the evaluation of key observables such as the branching ratios and, where available, angular observables, for radiative, leptonic, and semileptonic B decays, as well as for the relevant kaon and D-meson decays, together with the muon anomalous magnetic moment (g-2). The inputs can be provided through JSON/YAML configuration files and Les Houches Accord files, either supplied by the user or generated by external spectrum calculators. HyperIso therefore provides a flexible and extensible tool for flavour studies, phenomenological scans and the validation of BSM scenarios.
hep-ph0 citations
31
Theoretical uncertainties in reconstructing model parameters with gravitational waves from supercooled phase transitions
Maciej Kierkla🇸🇪 · Marek Lewicki🇵🇱 · Philipp Schicho🇨🇭 · Daniel Schmitt🇩🇪 · Bogumila Swiezewska🇵🇱
Future interferometers may detect a gravitational-wave (GW) signal from a cosmological first-order phase transition. Reconstructing the underlying particle-physics model from such a signal requires theoretical control over the map from microphysics to the spectrum. For classically scale-invariant extensions of the Standard Model, which generically predict strongly supercooled transitions and strong GW signals, this map depends sensitively on the treatment of quantum and thermal corrections to the nucleation rate. Taking the classically conformal $U (1)_{X}$ model as representative of this class, we scan its parameter space and compare two resummation schemes. The first is a high-temperature effective field theory, matched at two-loop level and including next-to-leading-order corrections to the bounce action, with the nucleation-rate prefactor given by the full one-loop functional determinants. The second is a commonly employed daisy-resummed effective potential, with the prefactor estimated on dimensional grounds. Reconstructing the fundamental model parameters through a Fisher-matrix analysis of injected GW signals at LISA, we find that the daisy-resummation scheme is strongly disfavored, as its theoretical error dominates over the reconstruction uncertainty.
hep-phastro-ph.COgr-qchep-th2 citations
32
Wounded parton scaling of multiplicities in ultra-relativistic light- and heavy-ion collisions
Rupam Samanta🇵🇱 · Piotr Bozek🇵🇱 · Wojciech Broniowski🇵🇱
Multiplicities of charged particles produced in O+O, Ne+Ne, Xe+Xe, and Pb+Pb collisions at $s_{N N} \sim 5$ ~TeV are studied in a uniform way within a wounded parton Glauber framework with overlaid negative binomial fluctuations. In this model, the nucleon's inelastic interaction is modeled via its constituent partons, whose number is a parameter, with best description obtained with four partons per nucleon. We fit directly the experimental multiplicity distributions (histograms), using {\it the same model parameters} for each reaction. The fit is performed in the c=1--80 $%$ centrality range. Avoiding the most peripheral events makes the method insensitive to the normalization issues caused by the difficulty in separating the Coulomb interactions, whereas the most central collisions may involve a different particle production mechanism. We find a proper model description of multiplicity distributions across all the studied systems for $c ≲ 1%$ .
↳ nucl-thhep-phnucl-ex0 citations
33
Particle accelerators as a path to intergovernmental collaboration: the case of the first electron positron collider and the power of theoretical physics
Giulia Pancheri🇮🇹
I rivisit the history of the first matter-antimatter collider built in Italy in 1960 and carried to success through an inter-European collaboration with France, underlying the foundational role of the Austrian born theoretical physicist Bruno Touschek. Touschek's life path through Europe before and after World War II is briefly recalled. The role of CERN in jump-starting this international collaboration between the Frascati National Laboratories in Italy and the Orsay Linear Accelerator Laboratory in France, is highlighted through historical documents, and contributions from interviews with the main protagonists of Touschek's game-changing proposal.
↳ physics.hist-phhep-ph0 citations
34
Electric field fluctuations and renormalization group flows in a self-interacting scalar field theory
Melanie Martínez🇪🇸 · Enrique Muñoz🇨🇱 · Marcelo Loewe🇨🇱
We consider a self interacting charged scalar field represented by the complex {\lambda}{\phi}4 model, embedded in a background electric field exhibiting classical stochastic fluctuations. We studied the effects of the classical stochastic noise on the physical parameters of the scalar field theory, for both weak and ultra strong electric field regimes. The stochastic background electric field is included in the Schwinger propagator through the covariant derivative, and the generating functional of the theory is found by means of the replica trick in order to compute the statistical average over electric fluctuations. As a result of the averaging process, an effective interaction between charged currents emerges, with a coupling constant proportional to the magnitude of the auto-correlation function of the electric field fluctuations. We obtained the dressed propagators, the interaction vertices, and the renormalization group equations of the theory, along with the corresponding streamplots in the manifold of interaction couplings.
↳ hep-thhep-ph0 citations
35
How many degrees of freedom describe a quantum N-particle state?
Matthew J. Lake🇷🇴 · Marek L. Miller🇩🇰
In Newtonian spacetime, the canonical description of a classical $N$ -particle system requires $3 N$ degrees of freedom. Not all of these are physical, however, since the conservation of the net momentum implies that only $3 (N - 1)$ accelerations are independent. Hence, three constraints can be used to eliminate the unphysical centre-of-mass variables, at the level of the Lagrangian, leaving only the subset of observable displacements and momenta, which are relational. Imposing the constraints does not change the dynamics of these variables, at the classical level, and is analogous to a gauge-fixing procedure, which removes redundancy in the description of the system. In classical physics, therefore, the number of physical degrees of freedom equals the number of independent relational degrees of freedom. Here, we show that this is not the case in quantum mechanics. While an operator-analogue of the classical net momentum exists, it cannot be used to impose constraints that restrict the degrees of freedom in the theory, without a loss of physical information. This means that all $3 N$ canonical degrees of freedom are physical, even though only $3 (N - 1)$ of them are relational. We explore the physical consequences of the non-relational variables and show that they give rise to generalised uncertainty relations (GURs), for the relational quantities that define the quantum reference frame (QRF). Hence, it is shown that the non-relational degrees of freedom refer to the frame itself and that the non-Heisenberg terms in the GURs define its Galilean-invariant spreads, in both real space and momentum space. The implications of this result for recent work on relational models, including the ``perspective neutral'' framework for QRFs, are discussed. Its implications for the wider relational program, and, in particular, the relevance of the latter to quantum gravity research, are also critically assessed
↳ quant-phgr-qchep-ph0 citations
36
Kaon-induced $ϕ Σ$ production off the proton
Sang-Ho Kim🇰🇷 · Myung-Ki Cheoun🇰🇷
We investigate the reaction mechanism of $K^{-} p \to ϕ Σ^{0}$ within a hybrid Regge approach based on effective Lagrangians. The nonresonant background includes Reggeized $t$ -channel $K$ and $K^{*}$ exchanges, together with ground-state $Σ$ and nucleon exchanges in the $s$ and $u$ channels, respectively. To describe the structures observed at $3.0 ⩽ P_{Lab} ⩽ 4.5$ GeV, we include the high-mass $Σ (2620)$ and $Σ (3000)$ resonances and examine the spin-parity assignments $J^{P} = 1/ 2^{\pm}$ , $3/ 2^{\pm}$ , and $5/ 2^{\pm}$ . The $K^{*}$ -Reggeon exchange dominates the forward-angle cross sections, whereas the smaller $K$ -Reggeon contribution is important for the total cross section at low energies and for the spin-density matrix elements. The nonresonant background alone is not sufficient to reproduce the local structures in the total cross section or the differential cross sections at large $- t^{'}$ . Including the two resonances, particularly the $Σ (3000)$ , substantially improves the agreement with the available data. The $J^{P} = 5/ 2^{-}$ assignment for the $Σ (3000)$ provides a reasonable overall description, although the present data do not permit a definitive determination.
↳ nucl-thhep-ph0 citations
37
Coulomb interaction in the diffraction description of the $^{12}$ C(d,p)X reaction
Yaroslav D. Krivenko-Emetov🇦🇹 · Boris I. Sydorenko
Within the Glauber-Sitenko diffraction multiple-scattering theory, we calculate Coulomb corrections to the invariant cross section for inclusive deuteron breakup in the $^{12}$ C(d,p)X reaction at small proton emission angles. Extending our previous analysis of the longitudinal momentum transfer $Q_{z}$ and the transverse relative momentum of the final $p n$ pair, we include the proton--nucleus electromagnetic interaction, Coulomb-nuclear interference, and the Coulomb correction to double $p n$ rescattering. For a finite nuclear charge distribution, we derive the Coulomb phase and relate its spatial scale to the measured charge radius. Closed and Yukawa-screened expressions for the proton Coulomb term are obtained. The two-dimensional correction to $p n$ rescattering is reduced to a one-dimensional integral without an independent Gaussian approximation to the full transition form factor. Calculations with the $S$ -wave components of the K2 and Nijm-I deuteron wave functions show that the Coulomb effect is concentrated near the quasifree peak. Its interference with the strong amplitude increases the peak height but decreases rapidly with relative momentum. It therefore cannot explain the experimental enhancement at $0.3$ -- $0.5$ GeV/ $c$ , where final-state interactions, relativistic corrections, and nonnucleonic components may be important.
↳ nucl-thhep-ph0 citations
38
Scalar glueball- $s s ˉ$ mixing in one flavor lattice QCD
Long-Cheng Gui🇨🇳 · Wei Sun🇨🇳 · Ying Chen🇨🇳 · Ming Gong🇨🇳 · Geng Li🇨🇳 · Zhaofeng Liu🇨🇳
We investigate the mixing between the lowest-lying scalar glueball and the $s s$ meson in $N_{f} = 1$ lattice quantum chromodynamics (QCD) utilizing an anisotropic $1 6^{3} \times 128$ lattice ensemble at a lattice spacing $a_{s} \approx 0.148 fm$ . By solving a generalized eigenvalue problem (GEVP) for the optimized glueball and $s s$ scalar operators in the $J^{PC} = 0^{++}$ channel, the masses of the two lowest-lying eigenstates are determined to be $m_{1} = 1.290 (20) GeV$ and $m_{2} = 1.777 (49) GeV$ . By extracting the couplings of these mass eigenstates to the glueball and $s s ˉ$ operators, we determine a substantial mixing angle $∣ θ ∣ \approx 40.7 (2.7)^{\circ}$ and a large mixing energy $x_{s} = 239 (24)$ MeV. These results indicate a strong glueball- $s s ˉ$ mixing in the scalar sector, providing important non-perturbative inputs for understanding the nature of the experimental isoscalar scalar mesons. The continuum limit of the mixing energy and its quark mass dependence need to be investigated in the future.
↳ hep-lathep-exhep-ph0 citations
39
Rapidity-even Dipolar Flow in Relativistic Heavy-Ion Collisions
Niseem Magdy🇺🇸
Rapidity-even directed flow, ( $v_{1}^{e v e n}$ ), provides a sensitive probe of fluctuation-driven dipolar asymmetry in the initial state of relativistic heavy-ion collisions. Its extraction is complicated by large first-harmonic non-flow correlations, particularly those induced by global momentum conservation (GMC). In this work, we study ( $v_{1}^{e v e n}$ ) and its multi-particle correlations in Au+Au collisions at ( $s_{N N} = 200$ ) GeV using the AMPT and HIJING models. An ( $η$ )-dependent weighting procedure is employed to suppress the leading GMC contribution. HIJING is used as a non-collective baseline, while AMPT is used to investigate sensitivity to final-state partonic transport. The GMC-corrected HIJING results are strongly reduced for most ( $v_{1}$ )-related observables, indicating that the leading HIJING-like recoil contribution is effectively mitigated. The AMPT calculations reproduce the characteristic sign-changing ( $p_{T}$ ) dependence of ( $v_{1}^{e v e n}$ ) and show sensitivity to the partonic scattering strength. Mixed-harmonic and normalized correlations involving ( $v_{1}$ ), ( $v_{2}$ ), and ( $v_{3}$ ) suggest that the dipolar mode is correlated with both the elliptic geometry and fluctuation-driven triangular structure. These results demonstrate that GMC-suppressed rapidity-even dipolar-flow correlations provide a promising framework for constraining initial-state fluctuations and final-state transport in heavy-ion collisions.
↳ nucl-thhep-ph0 citations
40
The next-to-next-to-leading order BFKL eigenvalue at odd conformal spin in planar N=4 super Yang-Mills
Alexander Prygarin🇮🇱 · Claudelle Capasia Madjuogang Sandeu🇮🇱
We give the next-to-next-to-leading order color-singlet BFKL eigenvalue of planar N=4 super Yang-Mills at odd conformal spin n in closed form. At the two lower orders the nested harmonic sums appear only at the two conjugate points z=(|n|-1)/2+i nu and zbar. At three loops they are evaluated on a ladder of integer-shifted arguments from the reflected point -zbar up to z, with one further point past it, the coefficient at a rung fixed by its two distances to the ladder ends. Seven families are the exception: their coefficients need a ladder sum whose summand shifts with the summation index. Rules uniform in the conformal spin produce all forty-seven families at every odd n>=3; no per-spin coefficient is tabulated in the definition, and the n=1 boundary block is supplied separately. Those rules are a reconstruction from the computed spins, exact at every one of them, verified over the range n<=99 and at the holdout spin n=101, and not proved at arbitrary odd n. Each atom-table coefficient is a rational combination of 1, pi^2 and zeta_3, coefficient and atom sharing the transcendental weight five. Along nu=0 the intercepts match the Quantum Spectral Curve values at each computed odd spin up to n=91, which tests the integrand and the reduction together at one point of each spin, and for most of them for the first time. Away from that line the closed form gives the collinear behavior of the block uniformly in the spin, which the intercepts alone do not fix.
↳ hep-thhep-ph1 citation
41
Repulsive dark matter from Hosotani mechanism
Philippe Brax🇫🇷 · Patrick Valageas🇫🇷
We build an ultralight dark matter model with repulsive self-interactions, starting from a 5D action that only includes a $U (1)$ gauge field and several massive and charged free fermions. The dark matter scalar field corresponds to the fifth component of the gauge field, after compactification to 4D. Although the single-fermion case only leads to attractive self-interactions, two fermions can already give rise to repulsive self-interactions, thanks to a Scherk-Schwarz twist around the fifth dimension. We check the observational and theoretical self-consistency of this scenario, from the inflation stage to the current time. We find that large ranges of model parameters are allowed. For scalar masses below $1 0^{- 12}$ eV the self-interactions are negligible and the model behaves as fuzzy dark matter. For higher masses the repulsive self-interactions govern the formation of solitons of astrophysical size. Larger sizes require a large initial misalignment or small masses in the fuzzy dark matter regime.
↳ astro-ph.COhep-phhep-th0 citations
42
Renormalization of meson susceptibilities and RG-invariant symmetry ratios in QCD
Ting-Wai Chiu🇹🇼
We analyze the ultraviolet divergence structure of meson susceptibilities in finite-temperature QCD, for lattice formulations with exact chiral symmetry. The bare susceptibility separates into additive divergences and a multiplicative renormalization $Z_{Γ}^{2}$ . The additive divergences are temperature-independent, and are removed by the temperature subtraction. They consist of the leading power divergence $α_{Γ} / (2 a^{2})$ from the identity operator, together with a mass-dependent logarithmic term $\propto m^{2} ln (1/ (am))$ . Exact chiral symmetry forbids all mass-dependent \emph{power} divergences of the susceptibility. The multiplicative factor $Z_{Γ}^{2}$ has a logarithmic dependence on the lattice spacing, controlled by the operator anomalous dimension. We show that the symmetry ratio $κ_{A B} = (χ_{A}^{reg} - χ_{B}^{reg}) / (χ_{A}^{reg} + χ_{B}^{reg})$ , built from temperature-subtracted susceptibilities of symmetry partners, is exactly renormalization-group invariant and scheme-independent. The additive divergence is removed by the subtraction, and the multiplicative factor cancels through the equality $Z_{A} = Z_{B}$ . This equality holds for any number of flavors and any quark masses in a mass-independent scheme, unaffected by spontaneous symmetry breaking or the $U (1)_{A}$ anomaly. We derive the complete $Z$ -factor chains for all meson channels and contrast the divergence structure with that of Wilson fermions, for which the explicit chiral-symmetry breaking induces a chiral-odd power-divergent mixing and spoils the equality $Z_{A} = Z_{B}$ on which the construction relies.
↳ hep-lathep-phhep-th1 citation
43
Leading Yukawa terms in the three-loop anomalous dimension and four-loop $β$ -function of $N = 1$ supersymmetric theories for various renormalization prescriptions
Ratmir Jumanov🇷🇺 · Konstantin Stepanyantz🇷🇺
For an arbitrary renormalizable $N = 1$ supersymmetric theory with a single gauge coupling regularized by higher covariant derivatives we calculate the three-loop contribution to the anomalous dimension of the matter superfields proportional to the sixth powers of Yukawa couplings for a wide class of renormalization prescriptions. Next, taking into account that in the case of using the higher covariant derivatives supplemented by minimal subtractions of logarithms the NSVZ relation is valid in all orders, we calculate the corresponding four-loop contribution to the gauge $β$ -function and investigate its scheme dependence. In particular, we construct the so-called ``minimal'' renormalization prescription for which the renormalization group functions have the simplest possible form provided that the exact equations for the gauge and Yukawa $β$ -functions following from supersymmetry remain valid.
↳ hep-thhep-ph0 citations
44
Magnetically assisted primordial scalar perturbations: Scalar-Induced Gravitational Waves
Arko Bhaumik🇮🇳 · Theodoros Papanikolaou🇮🇹 · Anish Ghoshal🇬🇧
Primordial magnetic fields (PMFs) provide a well-motivated source of cosmological perturbations through their anisotropic stress and may leave observable imprints in both the scalar and tensor sectors. In this work, we study scalar metric perturbations sourced by a PMF evolving through a finite post-inflationary epoch characterized by a constant equation-of-state (EoS) parameter $w$ . Working in a gauge-invariant framework, we derive the sourced evolution equation for the Bardeen gravitational potential in a general constant- $w$ background. Our analysis indicates faster (slower) growth of PMF-sourced scalar perturbations on superhorizon scales for a stiffer $w > 1/3$ (softer $w < 1/3$ ) background compared to the marginal radiation-dominated scenario with $w = 1/3$ . We then derive the scalar-induced gravitational wave (SIGW) background induced at second order by the magnetically generated scalar perturbations. Our analysis indicates a narrow viable parametric region for a kination-like post-inflationary era and a nearly scale-invariant PMF that may give rise to a PMF-sourced SIGW signal dominating over the direct PMF-generated tensor background. Simultaneously, the induced tensor modes are found to be perturbatively small compared to the magnetic sector, which, in turn, exerts negligible backreaction on the background. Interestingly enough, for an inflationary scale $H_{inf} \sim 1 0^{3} - 1 0^{9}$ GeV and duration of reheating in $e$ -folds $N_{reh} \sim 8 - 10$ , the dominant PMF-sourced SIGW signal may be detectable by next-generation terrestrial and space-based interferometric GW detectors spanning the mHz $-$ kHz frequency range.
↳ astro-ph.COgr-qchep-ph3 citations
45
Sensing relativistic quantum fields with minimally perturbing local measurements
F. Daem🇫🇷 · L. Ballesteros Ferraz🇫🇷 · A. Zampeli🇵🇱 · A. Matzkin🇫🇷
We develop a framework for minimally perturbing local measurements in relativistic quantum field theory, with the aim to sense local properties of the field in a non-destructive manner. The field properties are sensed by weakly coupled pointers and encapsulated in conditional expectation values dependent on a postselection of the field state. Our operational protocol uses causally admissible Kraus updates for the field, in line with recent relativistic measurement theories, keeping in mind restrictions related to ``impossible measurements''. We illustrate our approach with three applications: a spacelikeness detector for causal-structure sensing, counting particle-creation densities in a supercritical potential and non-destructive discrimination between entangled states of the field and mixtures.
↳ quant-phhep-phhep-th0 citations
46
Biased Domain Wall Networks and their Gravitational Waves
Davide Barbini🇪🇸 · Alessio Notari🇮🇹 · Oriol Pujolàs🇪🇸 · Fabrizio Rompineve🇪🇸 · Francisco Torrentí🇪🇸
Cosmic Domain Wall networks are among the most interesting sources of a stochastic Gravitational Wave (GW) background from the early Universe. We present a thorough analysis of their annihilation, with a focus on scenarios where the collapse is induced by a population bias, whereby one of two degenerate vacua is initially preferred over the other. Our state-of-the-art $3 + 1$ lattice field theory simulations in the expanding Universe reveal that the network decays around the temperature $T_{ann} \sim T_{s} B_{s}^{0.8}$ , where $B_{s}$ quantifies the preference for one vacuum over the other at the onset of the scaling regime at the temperature $T_{s}$ . Furthermore, we obtain the spectrum of GWs from such networks, and provide a detailed comparison with the alternative potential bias annihilation mechanism that relies on a small explicit symmetry breaking in the potential. En passant, we update results on the evolution of these networks and on their GWs, and clarify existing disagreements in the recent literature. Our results sharpen the phenomenological viability of spontaneously broken discrete symmetries, and provide GW spectra that Pulsar Timing Arrays (PTAs) and ground-based interferometers (LIGO-Virgo-KAGRA) can readily use in their searches for a cosmological GW background.
↳ astro-ph.COhep-ph4 citations
47
Benchmarking wall velocities in cosmological phase transitions: Fluid Ansatz and WallGo
Gláuber C. Dorsch🇧🇷 · Marek Lewicki🇵🇱 · Daniel A. Pinto🇵🇱
A reliable computation of the bubble wall velocity during a cosmological phase transition requires an adequate modeling of the non-equilibrium dynamics in the vicinity of this expanding bubble. This task can be made computationally faster by imposing an \emph{Ansatz} on the shape of the non-equilibrium particle distribution function, thus simplifying the collision terms and making the Boltzmann equation solvable in terms of some out-of-equilibrium fluctuations. Two different \emph{Ansätze} have prevailed in the recent literature: the so-called fluid \emph{Ansatz} and an expansion in a basis of Chebyshev polynomials, consolidated in the public code \texttt{WallGo}. In this work we show that the two approaches yield essentially the same wall velocity in the regime of reasonably mild phase transitions, $α ≲ 0.01$ . Interestingly, the agreement is excellent when only top-quark annihilation is considered, but a noticeable discrepancy appears once scattering processes are included. We also investigate the limitations of linearizing the Boltzmann equation when the fluid \emph{Ansatz} is applied to stronger phase transitions, showing that non-linear contributions induce significant shifts in the predicted terminal velocity as $α \to 1$ , even though the non-linear contribution to the wall pressure remain quantitatively small compared to the equilibrium and linearized non-equilibrium parts. We discuss possible consequences of this result for both \emph{Ansätze}, while also highlighting the possible limitations of the WKB approach itself when applied to the regime of strong transitions. Since strong phase transitions are precisely the primary targets for future gravitational waves observatories, our study emphasizes that not only higher precision computations of $v_{w}$ in the semi-classical approach are required, but a treatment beyond the WKB approximation may be needed.
↳ astro-ph.COhep-ph1 citation

Affiliations

first authorsco-authorsvia INSPIRE