HEP Phenomenology·hep-ph

Wed·Aug 19, 2026Wednesday·August 19, 2026

32 papers—22 primary·10 cross-listed

01
Effective propagators of flavor neutrinos
Maxim Dvornikov🇷🇺
We analyze the possibility to construct propagators of flavor neutrinos, which are particles with indefinite masses. This kind of propagators was used previously while studying neutrino flavor oscillations in frames of the quantum field theory (QFT) based approach. Starting with the operator and the path integral formulations of the QFT, we obtain that the naive derivation of propagators for flavor neutrinos violates the basic principles of the QFT. Nevertheless, we can still construct the effective propagator of flavor neutrinos considering the mass mixing term as a perturbation. In this situation, the effective propagator arises from the solution of a Dyson-like equation. We use the derived effective propagator to rederive the quantum mechanical transition probability for neutrino oscillations in vacuum in frames of the QFT. The application of the obtained results to neutrino oscillations in background matter is also considered.
hep-phhep-th0 citations
02
Quadruple-Higgs boson production at the high-luminosity LHC
Andreas Papaefstathiou🇺🇸 · Gilberto Tetlalmatzi-Xolocotzi🇩🇪
We investigate the production of four Higgs bosons via gluon fusion at the high-luminosity LHC. We construct a phenomenological analysis of the eight- $b$ -jet final state and use a multivariate analysis to derive expected simultaneous constraints on the triple and quartic Higgs boson self-coupling modifications. At 95% confidence level, the resulting region projects onto $- 10.3 < c_{3} < 11.2$ and $- 222 < d_{4} < 234$ , where $c_{3} = κ_{3} - 1$ and $d_{4} = κ_{4} - 1$ . We also examine how quadruple-Higgs boson production can enter a triple-Higgs boson signal region requiring at least six $b$ -tagged jets. In addition, we consider two extensions of the Standard Model scalar sector: a one-real-singlet extension yielding the direct resonant process $pp \to S \to hhhh$ , and a two-real-singlet extension yielding the cascade $pp \to h_{3} \to h_{2} h_{2} \to (hh) (hh)$ , where $S$ , $h_{2}$ and $h_{3}$ are new scalar resonances. For these processes, we derive expected upper limits on the quadruple-Higgs boson production cross sections as functions of the new scalar masses.
hep-phhep-ex1 citation
03
Probing the Internal Structure of $X (3872)$ via Magnetic Moment: Distinguishing Color-Singlet and Compact Configurations
M. Monemzadeh🇮🇷 · N. Tazimi🇮🇷
The nature of the $X (3872)$ exotic hadron remains one of the most debated questions in hadron spectroscopy. We calculate its magnetic moment within a non-relativistic quark model that includes the three-body force arising from the cubic Casimir operator of $S U (3)_{C}$ with consistent dimensional analysis. Unlike previous works that used an uncontrolled large coupling, we fix the three-body strength using the realistic value of $\sim 10$ -- $20$ MeV extracted from the recent analysis of Noh et al.~(2024) based on lattice QCD and baryon spectroscopy. We find that the magnetic moment predictions fall into two distinct regions: the pure color-singlet configuration yields $μ_{X} = - 0.99 \pm 0.02 μ_{N}$ , while the compact configurations yield $μ_{X} = - 1.17$ to $- 1.23 μ_{N}$ . The difference between the two compact scenarios ( $0.06 μ_{N}$ ) is comparable to the systematic uncertainty of the model ( $\sim 0.15 μ_{N}$ ) and should be interpreted with caution. However, the distinction between the pure color-singlet and the compact scenarios ( $\sim 0.18$ -- $0.24 μ_{N}$ ) is larger than the estimated model systematic uncertainty and may provide a qualitative structural indicator. We emphasize that the pure color-singlet configuration is a simplified proxy for a molecule and does not represent a physical $D^{0} D ˉ^{* 0}$ molecule with large spatial extent. A full molecular treatment would require coupled-channel dynamics and long-range pion-exchange potentials, which are beyond the scope of this work. We also resolve a long-standing dimensional inconsistency in the cubic Casimir three-body force formulation and demonstrate through a detailed sensitivity and uncertainty analysis that our conclusions are robust for the physically relevant range of the three-body coupling.
hep-phhep-th0 citations
04
$C P$ -odd form factor in the $H W W$ vertex
A.I. Hernández-Juárez🇲🇽 · G. Tavares-Velasco🇲🇽 · J. Martínez-Ramón🇲🇽
We revisit the $C P$ -odd form factor in the $H W W$ vertex within the Standard Model (SM), which is induced only at the one-loop level when one of the $W$ bosons is off-shell. To the best of our knowledge, the numerical evaluation of this form factor is presented for the first time. The relevant contributions from quark loops are of order $1 0^{- 5}$ , well below the current experimental sensitivity. The phenomenological implications are studied through asymmetries in unpolarized and polarized observables in three-body decays.
hep-ph0 citations
05
Forward--backward asymmetry in the $H \to Z γ \to f f γ$ decay
A.I. Hernández-Juárez🇲🇽 · G. Tavares-Velasco🇲🇽 · A. Fernández-Téllez🇲🇽 · D. Watko🇲🇽
We study the forward--backward asymmetry in the three-body decay process $H \to Z γ \to f f γ$ , induced by complex form factors in the $H Z γ$ vertex. To estimate its magnitude, we derive constraints on the real and imaginary parts of the $C P$ -violating form factor $h_{3}^{Z γ}$ using current LHC measurements, obtaining upper limits of about $0.9$ GeV. These bounds are of the same order of magnitude as those derived from electric dipole moments (EDM). We find that the asymmetry can reach values of order $1 0^{- 1}$ and may be accessible at the HL-LHC.
hep-ph0 citations
06
The high-energy behavior of tree-level scattering in finite-temperature QCD: estimates of theoretical systematic uncertainty in jet-medium Monte Carlo simulations
Lukas Opitz🇨🇦 · Hemanth Regi🇨🇦 · Gojko Vujanovic🇨🇦
We examine the behavior of tree-level scattering in thermal QCD at high energies and find significant deviations away from the commonly used approximations [Phys. Rev. D 44, 1298 (1991), Phys. Rev. D 44, R2625 (1991), Phys. Rev. D.77, 014015 (2008), Phys. Rev. D. 77.114017 (2008)]. These deviations in the scattering rate also affect jet-medium transport coefficients at the partonic level, leading to a different kinematic dependence of the transverse momentum broadening per unit length $q^$ . As scattering rates and $q^$ are used by large-scale Monte Carlo simulations of jets in the quark-gluon plasma (QGP), such as [Phys. Rev. C 111,054913 (2025)], current constraints on $q^$ are biased owing to the approximations used therein. Besides theoretically improving $q^$ , the differences between the $q^$ herein and the approximate $q^$ used in jet Monte Carlo simulations are used to construct a theoretical systematic uncertainty, which in turn can be employed to devise a covariance matrix for $q^$ and enables updating the uncertainty bands on $q^$ obtained by Bayesian analysis.
hep-phnucl-exnucl-th0 citations
07
Closed-form expressions for tree-level gluon-gluon scattering: a framework for obtaining theoretical systematic uncertainties for jet-medium Monte Carlo simulations
Lukas Opitz🇨🇦 · Hemanth Regi🇨🇦 · Gojko Vujanovic🇨🇦
Modern Bayesian theory-to-data comparisons for jet-medium interactions, such as [Phys. Rev. C 111,054913 (2025)], are lacking the careful accounting of theoretical systematic uncertainties included within their uncertainty budget. Tree-level gluon-gluon scattering is revisited to establish a framework capable of quantifying theoretical systematic uncertainties to be used in Bayesian jet-medium constraints. The behavior of tree-level scattering in thermal QCD is examined in detail, finding deviations away from the commonly used approximations. Deviations in the scattering rate affect jet-medium transport coefficients at the partonic level, leading to a more intricate kinematic dependence for $q^$ and $e^$ than, say, the well-known logarithmic behavior. These deviations away from well-known behavior are used to estimate theoretical systematic uncertainties in Bayesian analysis.
hep-phnucl-exnucl-th0 citations
08
Reply to "Revisiting bounds on neutrino dark matter interaction at spikes"
James M. Cline🇨🇦 · Matteo Puel🇨🇦
We respond to arXiv:2607.08904, which commented on our previous work constraining neutrino-dark matter interactions from IceCube observations of neutrinos from active galactic nuclei.
hep-ph0 citations
09
Lepton flavor violating decays $l_{j} \to l_{i} γ$ in the $U (1)_{X}$ VLFM
Shuang Di🇨🇳 · Wei-Hang Zhang🇨🇳 · Zi-Xuan Su🇨🇳 · Guo-Zhu Ning🇨🇳 · Xing-Xing Dong🇨🇳 · Shu-Min Zhao🇨🇳
In the $U (1)_{X}$ vector-like fermion model ( $U (1)_{X}$ VLFM), the Standard Model(SM) gauge group is extended with an additional $U (1)_{X}$ symmetry. Vector-like fermions and right-handed neutrinos are introduced, providing new sources of lepton flavor violation(LFV). In this paper, we perform a detailed study of the LFV decays $l_{j} \to l_{i} γ$ (with $j = τ, μ$ ; $i = μ, e$ ; $i \neq = j$ ) in this model. The numerical results show that, in certain parameter regions, the branching ratios of these processes can become large enough to be probed in future experiments. This work provides important theoretical guidance and constraints for exploring new physics beyond the SM.
hep-ph0 citations
10
From the universal Lindblad equation to Boltzmann equations: in-QGP quarkonium dynamics
Aoumeur Daddi Hammou🇫🇷 · Pol Bernard Gossiaux🇫🇷
Recently, a set of coupled singlet-octet universal Lindblad equations (ULEs) was derived within the framework of non-relativistic QCD (NRQCD) to describe quarkonium dynamics in the quark-gluon plasma (QGP). These equations provide a unified quantum description spanning the quantum Brownian and quantum optical regimes. In this work, we further develop this framework and establish its connection with semiclassical transport. We first derive the universal Lindblad equations within the potential non-relativistic QCD (pNRQCD) effective field theory and show that they coincide with the small-dipole limit of the NRQCD ULEs. We then derive the semiclassical limit of the NRQCD ULEs, obtaining a set of coupled singlet-octet Boltzmann equations. To our knowledge, this is the first derivation of Boltzmann transport equations directly from the universal Lindblad framework. The resulting equations are valid beyond the small-dipole approximation, allowing the evolution of heavy-quark pairs from compact to widely separated configurations. Taking their small-dipole limit allows a direct comparison with the Boltzmann equations of Yao et al. [Phys. Rev. D 99, 096028 (2019)], which were derived within pNRQCD from the Davies secular equation, relying on the rotating-wave approximation (RWA). While the singlet equations are found to be in near-complete agreement, the octet equation contains an additional collision term describing transitions within the continuum of octet scattering states, which is absent from the RWA-based derivation. Finally, we derive the leading quantum correction to the singlet Boltzmann equation. Our results establish a more general and systematic theoretical foundation for the semiclassical transport description of quarkonium in the QGP.
hep-phhep-thnucl-thquant-ph0 citations
11
Seeding baryonic dark matter
Domenec Espriu🇪🇸
It has been proposed that primordial quark pellets or PQPs --ultra-dense quark-matter mini- stars-- formed at $T \sim 1$ GeV maybe a good candidate accounting for the dark matter of the universe. If correct, dark matter would consist of very compact objects with a maximum mass of $1 0^{- 2} M_{⊙}$ and radii of approximately 100 m, although smaller objects would be much more abundant and encompass the bulk of the dark matter content. Here we describe a viable formation mechanism based on the enhancement of the local baryon density when supra-horizon Peccei-Quinn domain walls formed at an earlier epoch sweep and accumulate quarks and gluons before entering the horizon. Assuming an efficient baryon concentration by contracting Peccei-Quinn domain walls, we derive the resulting primordial quark pellet mass spectrum, minimum mass and cosmological abundance The results confirm that PQPs potentially constitute a conservative, Standard-Model-based, and observationally viable solution to the dark-matter puzzle.
hep-phastro-ph.CO0 citations
12
Static and dynamic properties of Triply Heavy Baryons
Kinjal Patel🇮🇳 · Kaushal Thakkar🇮🇳
In this study, we investigate the ground-state masses, magnetic moments, transition magnetic moments, radiative decays, and heavy-to-heavy semileptonic decay rates, including their corresponding branching fractions of triply heavy baryons (THBs). The ground-state masses of the involved baryons are evaluated by numerically solving the six-dimensional hyperradial Schrödinger equation within the hypercentral constituent quark model (hCQM), incorporating both hyper-Coulomb and linear confinement potentials along with spin-dependent interactions. The electromagnetic properties are calculated using the spin-flavour wave functions and the effective constituent quark masses of the baryon. The semileptonic $b \to c$ decay widths are computed using the Isgur--Wise function within the heavy-quark spin symmetry, from which the corresponding branching ratios and lepton flavour universality ratios are also determined.
hep-ph0 citations
13
Characterize the properties of $D_{s}^{+}$ -meson decay constant and leptonic decays by using QCD sum rules within background field theory framework
Jian-Qi Chen🇨🇳 · Ya-Xiong Wang🇨🇳 · Hai-Bing Fu🇨🇳
The leptonic decays of the $D_{s}^{+}$ -meson have received considerable attention in recent years. In this work, we perform a precise calculation of the decay constant $f_{D_{s}^{+}}$ using the QCD sum rules method within the background field theory framework. In our calculation, we fully include the quark propagator contributions up to dimension-six condensates. By adopting two different constraint schemes, we obtain $f_{D_{s}^{+}}^{(I)} = 253. 0_{- 3.1}^{+ 3.3} MeV$ and $f_{D_{s}^{+}}^{(II)} = 251. 8_{- 1.3}^{+ 1.4} MeV$ , respectively, both of which are in good agreement with existing theoretical and experimental results. The conventional scheme follows the standard Borel window criteria, while the derivative scheme reduces the dependence of the decay constant on the Borel parameter through an auxiliary function. Based on these decay constants and incorporating the NLO electroweak radiative corrections, we further calculate the branching fractions for the three leptonic decay channels for both schemes. Combined with the latest branching fraction $B (D_{s}^{+} \to μ^{+} ν_{μ})$ from the PDG, we extract the CKM matrix elements $∣ V_{cs} ∣^{(I)} = 0.967 \pm 0.012$ and $∣ V_{cs} ∣^{(II)} = 0.970 \pm 0.005$ from the two schemes, respectively.
hep-ph0 citations
14
An Exact Analytical Bridge from Complex Yukawa Couplings to Fermion Masses and CKM/PMNS Mixing
Chilong Lin🇰🇷
The origin of fermion masses and flavor mixing is often obscured by standard Euler-angle parameterizations, which mask the underlying connection between physical observables and Yukawa couplings. We prove that introducing a single, remarkably weak yet physically grounded commutation hypothesis, $[M_{R}^{2}, M_{I}^{2}] = 0$ , on the Hermitian mass-squared matrix $M^{2} = M \cdot M^{†}$ systematically reduces a general 18-parameter complex mass matrix $M$ down to a 5-parameter form per sector that admits \emph{exact} analytic diagonalization. The resulting mass eigenvalues are closed-form algebraic expressions that completely bypass the transcendental Cardano trigonometric reduction required for generic Hermitian matrices, while the diagonalizing unitary matrix $U_{f}$ depends solely on two parameters that form a dimensionless 2D geometric flavor-ratio vector $v_{f} = (x, y)$ . Combining two such sectors yields the physical CKM/PMNS mixing matrix directly as $V = U_{1}^{†} (v_{1}) \cdot U_{2} (v_{2})$ , establishing a direct, first-principles analytical bridge from raw Yukawa couplings to fermion masses and mixing matrices without intermediate phenomenological inputs. Finally, we highlight that this exact leading-order baseline enforces an exact four-fold moduli degeneracy among mixing elements, pointing directly toward non-commuting extensions for full phenomenological precision.
hep-ph0 citations
15
Anomaly-Induced Phenomena with Massive Fermions: Higher-Landau-Level Dominance from Spatially Modulated Electric Fields
Koichi Hattori🇨🇳 · Kazuya Mameda🇯🇵 · Takeru Uchiyama🇯🇵 · Di-Lun Yang🇹🇼
We investigate the axial Ward identity for massive fermions under a constant magnetic field at arbitrary strength, maintaining an arbitrary spacetime configuration of a perturbative electric field. We show that a spatially modulated electric field prevents the exact cancellation between the anomaly and pseudoscalar terms, generating a local axial-charge source even in the adiabatic regime where the frequency is subthreshold to massive-fermion production. Remarkably, unlike conventional magnetic responses, this charge generation is dominated not by the contribution of the lowest Landau level, but by those of the higher Landau levels. Our findings provide a microscopic foundation for anomaly-induced transport and anomalous optical responses in gapped systems. In particular, we find that the spatially modulated chiral magnetic effect in weakly gapped Weyl semimetals that exhibits a linear suppression of the magneto-resistance by the magnetic-field strength instead of the renowned quadratic suppression.
hep-phcond-mat.mes-hallhep-th0 citations
16
Precise Measurement of $δ$ at LBL Experiments Using Only The Neutrino Sector
Emilio Ciuffoli🇨🇳
Currently, the CP-violating phase $δ$ is the least precisely known among the neutrino mixing parameters. In the coming years, accelerator neutrino experiments such as DUNE and Hyper-K will measure $δ$ , significantly increasing the precision. Such a measurement is usually performed by comparing the oscillation probabilities in the neutrino and antineutrino sectors, thereby directly observing the CP violation. This approach, however, has some downsides: in particular, it is more challenging to obtain good statistics in the antineutrino sector, leading to increased statistical errors. In principle, however, it is possible to determine $δ$ by looking only at the neutrino sector, studying the energy dependence of the oscillation probability. We investigate this possibility in detail; we find that, if this approach is used, the main issue would be the degeneracies with other mixing parameters, which affect the sensitivity to $δ$ . Those parameters, however, have already been measured with great precision, which will increase even more in the next few years; if those constraints are taken into account by introducing Gaussian penalty terms in the $χ^{2}$ , it is possible to achieve better results focusing only on the neutrino sector, rather than using the standard approach. Those degeneracies could also be broken by exploring a wider range of $L / E$ : this can be achieved, for instance, by increasing the neutrino energy. In this way, the total beam intensity could also increase due to the relativistic boost (however, the conversion efficiency could decrease, affecting the total luminosity). We find that if the relativistic boost increases the number of events in the high-energy configuration, the best performance would be achieved in such a set-up; otherwise, the optimal approach would be to focus only on the neutrino mode without changing the beam energy.
hep-ph0 citations
17
An axion constraint from the diffuse supernova neutrino background indicated by Super-Kamiokande
Kanji Mori🇯🇵 · Tomoya Takiwaki🇯🇵 · Kazunori Kohri🇯🇵 · Masamitsu Mori🇯🇵
Recently, the Super-Kamiokande Collaboration reported an indication of the diffuse supernova neutrino background (DSNB) with a statistical significance of $2.6 σ$ . Motivated by this possible discovery, we investigate the impact of axion cooling on the DSNB flux on the basis of long-term neutrino-radiation hydrodynamic simulations. We compare the observed flux and our models and obtain a $1 σ$ upper limit $∣ g_{a p} ∣ < 1.3 \times 1 0^{- 9}$ on the axion-proton coupling constant, which is comparable to the conventional limit based on the SN 1987A neutrino burst. In contrast to the SN 1987A bound, the DSNB constraint does not rely on the properties of a single observed supernova, because the DSNB represents the cumulative neutrino emission from a cosmic population of core-collapse events. More generally, this approach can be applied to other feebly interacting particles that modify protoneutron-star cooling.
hep-phastro-ph.COastro-ph.HE0 citations
18
Entanglement of back-to-back gluon pair
Lei Yang🇨🇳 · Wen-Hao Yao🇨🇳 · Yu-Kun Song🇨🇳 · Shu-Yi Wei🇨🇳
We investigate the polarization correlation of back-to-back gluon pairs in unpolarized $pp$ collisions and compute their density matrix. For gluon pairs produced through $q q ˉ$ annihilation, the linear polarization correlation is sizable, even reaching unity when the final-state gluons are emitted perpendicular to the beam direction in the $q q ˉ$ rest frame. Combining with the fact that their helicity remains maximally correlated across different scattering angle, the gluon pair system thus resides in a maximally entangled Bell state in this configuration. In contrast, for the $g g \to g g$ channel, both the helicity and linear polarization correlations are considerably suppressed, producing a separable state. Nonetheless, it still retains an appreciable linear polarization correlation of about $11%$ at central scattering in unpolarized collisions. The linearly polarization correlation of the back-to-back gluon pair can further increase when the incoming gluons are circularly polarized. Employing the anisotropy of energy correlators, we demonstrate that the linear polarization correlation of gluon pairs can be extracted from the $cos 2ΔΦ$ modulation.
hep-phhep-ex0 citations
19
VERaiPHY -- Validation & Evaluation for Robust AI in PHYsics
Gaia Grosso🇺🇸 · Ramon Winterhalder🇮🇹 · Lydia Brenner🇳🇱 · Louis Lyons🇬🇧 · Tilman Plehn🇩🇪
Modern machine learning is leading to substantial gains in precision, flexibility, and computational efficiency in fundamental physics. Statistical validation, uncertainty quantification, and robustness assessment are less systematically addressed. The VERaiPHY initiative (Validation & Evaluation for Robust AI in PHYsics) is a series of articles developed within the PHYSTAT programme, aimed at establishing statistical standards for the development, evaluation, and deployment of ML techniques. Each article focuses on a specific methodological domain from a statistics perspective and clarifies statistical questions, tests, and the interpretation of results. This opening article establishes the probabilistic, statistical, and machine learning foundations that the later contributions assume, together with the notation used throughout.
hep-phastro-ph.COhep-exphysics.data-an+11 citation
20
Bound-state spectra of $χ_{c J}$ in finite nuclei and the universal pattern of mass levels
Tian-Le Gao🇨🇳 · Ze-Hua Zhang🇨🇳 · Xiang Liu🇨🇳
In this work, we investigate possible $χ_{c J}$ --nuclear bound states with $J = 0, 1, 2$ using in-medium mass shifts generated by virtual $D^{(*)} D ˉ^{(*)}$ loops within an unquenched framework. The resulting $χ_{c J}$ --nucleus potentials are constructed in the local density approximation, and the bound state spectra are calculated for $^{12} C$ , $^{16} O$ , $^{40} Ca$ , $^{90} Zr$ , $^{197} Au$ , and $^{208} Pb$ . Bound states are obtained for all systems considered. The $χ_{c 0} (1 P)$ and $χ_{c 1} (1 P)$ spectra are nearly degenerate, whereas the larger in-medium mass shift of $χ_{c 2} (1 P)$ leads to deeper binding. Although the absolute bound state energies depend appreciably on the cutoff parameter, the energy differences relative to the $1 s$ level are considerably less sensitive to it and exhibit a regular pattern that decreases approximately as $A^{- 2/3}$ with increasing nuclear mass number. A cosh-type potential with a common nuclear geometry provides a compact description of these spectra. The predicted bound-state structures and level-spacing systematics could be investigated in future high-statistics near-threshold photoproduction experiments at the upgraded JLab facility.
hep-phhep-exnucl-exnucl-th0 citations
21
Resolved Photon Processes: A Tribute to Rohini Godbole
Manuel Drees🇩🇪
Hadrons are particles composed of elementary quarks and gluons, which have strong interactions described by Quantum Chromodynamics (QCD); examples are protons and neutrons, which bind to form atomic nuclei. In contrast, photons are usually thought of as the elementary force carriers of quantum electrodynamics (QED). However, at the quantum level a photon can fluctuate into a quark antiquark pair. At sufficiently high energies these virtual quarks can become real, physical particles by interacting with other particles, in particular with other hadrons. In this way photons with energies exceeding a few GeV acquire properties of a hadron. Resolved photon processes are reactions that probe these hadronic properties. These processes often dominate the production of hadronic final states, including jets (sprays of collimated hadrons), at electron--proton and electron--positron colliders. Implications of this for backgrounds at future high--energy lepton colliders remain poorly understood.
hep-ph0 citations
22
Can $γ γ$ collisions rival $e^{-} e^{+}$ in probing doubly charged Higgs bosons?
Abdesslam Arhrib🇲🇦 · Rachid Benbrik🇲🇦 · Mohammed Boukidi🇵🇱 · Mohamed Chabab🇲🇦 · Khalid Goure🇲🇦 · Stefano Moretti🇬🇧
High-energy $γ γ$ collisions, realizable as an operational mode of future lepton linear colliders such as the ILC and CLIC, provide a promising environment to probe extended Higgs sectors. We investigate the sensitivity of such colliders to doubly charged Higgs bosons within the 2-Higgs Doublet Model with type-II seesaw (2HDMcT). Focusing on the three-body production channels $γ γ \to H^{\pm\pm} H_{1}^{\mp} H_{1}^{\mp}$ and $γ γ \to H^{\pm\pm} H_{1}^{\mp} W^{\mp}$ , we perform a parameter space scan consistent with theoretical constraints as well as current collider, flavor, and electroweak precision observables (EWPOs). We show that $γ γ$ collisions can rival the discovery potential of the conventional $e^{+} e^{-}$ mode for probing doubly charged Higgs bosons through a $4 ℓ + E_{T}^{mi ss}$ signature ( $ℓ = e, μ$ ). Despite the reduced effective luminosity resulting from the photon spectrum, the significantly enhanced production cross sections, exceeding those in electron-positron collisions by more than one order of magnitude, compensate for this limitation. By performing a detailed signal-to-background analysis at center-of-mass energies of $s = 830$ and $1245$ GeV, we demonstrate that a discovery significance at the $5 σ$ level can be achieved for viable benchmark points (BPs).
hep-ph0 citations
23
Deconfinement-Higgs continuity in $SU (2)$ adjoint Higgs model at finite temperature
Yui Hayashi🇯🇵 · Masashi Kawahira🇯🇵 · Hiromasa Watanabe🇯🇵
We study the finite-temperature phase structure of the four-dimensional $SU (2)$ adjoint Higgs model, focusing on a possible \textit{deconfinement-Higgs continuity}: the conjecture that the high-temperature deconfined phase of Yang-Mills theory and the finite-temperature Higgs phase form a single thermodynamic phase. We first perform a global-symmetry analysis, showing that the Higgs and deconfined regimes are expected to share the same symmetry pattern, which is distinct from that of the confined phase. This suggests deconfinement-Higgs continuity, but does not exclude the possibility that the deconfined phase and the Higgs phase are separated by a phase transition not associated with the global symmetries. We then perform a deformation analysis, which yields an explicit continuous path between the ``deconfined symmetric'' and ``deconfined Higgs'' regions in a reduced three-dimensional lattice model. These results indicate that the Higgs and deconfined regimes can be continuously connected, while the confined phase remains distinct.
↳ hep-thhep-lathep-ph0 citations
24
Composite worldline instantons and the nonperturbative particle decay in constant external electric and magnetic fields
Alexander Gorsky🇷🇺 · Ivan Poluboyarinov🇷🇺
In this paper, we discuss the validity of the composite worldline instanton approach for the nonperturbative decay of charged particles in constant electric and magnetic fields. It is shown that the instanton results in the leading exponential approximation in the different limits agree with the ones obtained by the imaginary part of the self-energy in the external field and by overlap of the wave functions. We comment on the possible application of our results for the estimation of the decay rate of the proton in the external electric and magnetic field in the leading exponential approximation. The effects of entanglement of the particles in the final state are briefly mentioned.
↳ hep-thcond-mat.stat-mechhep-ph0 citations
25
Spectral Fingerprints Beyond Degeneracies in Primordial Gravitational-Wave Sources
Subhasis Maiti🇮🇳
Stochastic gravitational-wave backgrounds from different primordial mechanisms can produce identical peak frequencies and amplitudes, obscuring their physical origin. We show that the broadband spectral shape breaks this degeneracy. Comparing scalar-induced and gauge-field-induced gravitational waves for identical primordial spectral profiles and cosmological evolution, we find that their spectra retain distinct source-dependent signatures even after matching both the peak frequency and amplitude. While the two mechanisms share a universal deep-infrared behavior, their tensor-source kernels generate different peak morphologies and ultraviolet asymptotic scalings. In particular, the ultraviolet spectrum provides a direct diagnostic of the underlying source mechanism that is insensitive to the overall normalization. Our analysis shows that broadband spectral information contains additional source-dependent signatures that are inaccessible from peak observables alone.
↳ astro-ph.COhep-ph1 citation
26
Astrophysical Graviton Squeezing Can Be Hidden in the Far-Field
Cheng-Jun Fang🇨🇳 · Zong-Kuan Guo🇨🇳 · Zhen-Hong Lyu🇨🇳 · Jing Shu🇨🇳 · Yu-Heng Sun🇨🇳 · Zi-Zheng Zhou🇨🇳
While localized astrophysical sources can generate macroscopic graviton squeezing, their observable quantum signatures at far-field detectors remain unresolved. In this work, we investigate the propagation dynamics of the squeezed states using spatial quantum optics methods to evaluate correlation functions accessible to a local observer. Crucially, we reveal a severe kinematic conflict in same-cone measurements, which highly suppresses local quantum coherence. Consequently, these macroscopically squeezed states appear classically thermal to a single detector. Our results demonstrate that global squeezing does not guarantee local observability, and the measurable quantum signatures may be significantly weaker than what would be expected from the overall squeezing parameter of the state.
↳ gr-qchep-phquant-ph0 citations
27
Block Encoding Non-Abelian Lattice Gauge Theory
Patrick Draper🇺🇸
Gauge theories like lattice QCD present a complex problem for quantum simulation. In a basis where the electric part of the Hamiltonian is simple, the magnetic part, generally expressed as a sum over the plaquette operators of the lattice, is quite complicated, producing correlated transitions between several link and site degrees of freedom. We provide an efficient block encoding of the plaquette operator in the irrep basis, a refinement of the electric basis where the internal gauge-variant degrees of freedom are integrated out. The construction removes the plaquette matrix element scaling wall which has been a significant barrier for other approaches in this basis. The algorithm leverages a convenient factorization property of the matrix elements, cheap classical precomputation, and quantum oracles built from lookup tables and programmed rotations.
↳ quant-phhep-lathep-ph1 citation
28
Ostrogradsky's Theorem is Incompatible with Background Independence in Quantum Gravity
Ken-ji Hamada🇯🇵
Ostrogradsky's theorem shows that higher-derivative dynamical systems inevitably yields a Hamiltonian featuring a ghost mode that is unbounded from below. However, we argue that this theorem is inapplicable to gravitational systems, as the Hamiltonian constraint, which encodes background independence by dictating that the total Hamiltonian vanishes, holds strictly. The ghost mode obeying this constraint constitutes an indispensable component in the construction of space and time. Nevertheless, it should be underscored that the use of the weak-field (graviton) approximation, being a background-dependent scheme presupposing the existence of absolute time, invokes this theorem; consequently, it is allowed only in the domain below the Planck scale, where second derivative terms dominate.
↳ gr-qchep-phhep-thphysics.hist-ph0 citations
29
Density-induced dark-baryon conversion in $Δ -$ admixed hypernuclear neutron stars
Niyar Prabhat Kalita🇮🇳 · Vivek Baruah Thapa🇮🇳 · Bhanu Prakash Pant🇮🇳 · Anil Kumar🇵🇱 · Partha Konar🇮🇳
We investigate density-induced conversion of neutrons into a neutral dark baryon $χ$ in cold, charge-neutral, $β$ -equilibrated neutron-star matter containing hyperons and all $Δ (1232)$ quartet. The hadronic sector is modeled within a density-dependent covariant density-functional framework using the DDME2 parametrization. A scalar Higgs portal is included as a possible interaction channel between the visible and dark sectors, although its mean-field contribution is negligible for the couplings adopted here. Unlike fixed dark-matter admixture models or scenarios in which nucleon-to-DM conversion is driven by Higgs exchange, the $χ$ abundance is determined self-consistently from chemical equilibrium and baryon-number conservation. We find that hyperons and $Δ$ resonances alter the neutron chemical potential, delay the onset of $χ$ , and suppress its abundance relative to nucleonic matter. This competition induces characteristic changes in the equation of state, particle fractions, sound speed, and adiabatic index. For $m_{χ} = 1250$ , $1300$ , and $1400$ MeV, the maximum masses of the complete $N + Y + Δ + χ$ configurations are $1.806$ , $1.899$ , and $2.024, M_{⊙}$ , respectively, indicating that the massive-pulsar constraint disfavors the lighter dark-baryon benchmarks. The radial profiles further show that for $m_{χ} = 1400$ MeV, $χ$ is confined to the inner core of the most massive stars, while canonical configurations remain essentially unaffected. Thus, the stellar modifications arise primarily from conversion-induced rearrangement of the equilibrium composition rather than from Higgs-mediated interactions. These results highlight the importance of treating conventional non-nucleonic degrees of freedom and density-generated dark baryons on an equal footing when assessing the astrophysical viability of dark-sector extensions of dense matter.
↳ astro-ph.HEhep-phnucl-th0 citations
30
Generative artificial intelligence for reconstructing neutron-star matter
Julia Yu. Panteleeva🇩🇪 · Herzallah Alharazin🇩🇪 · Evgeny Epelbaum🇩🇪
Neutron-star cores hold the only known matter in the universe that is simultaneously cold and strongly interacting, compressed beyond nuclear density into a state of unknown composition. The equation of state links stellar masses, radii and tidal deformabilities to this regime, but recovering this key quantity from sparse observations is an ill-posed inverse problem. Existing analyses bury a prior in a fixed functional form, unevenly weighting admissible solutions and biasing the result. We reconstruct the equation of state with a denoising diffusion model that keeps prior, physics and data separate: it learns an inspectable, physically motivated prior anchored to first-principles nuclear theory, while perturbative-QCD and astrophysical constraints are imposed exactly. Future measurements therefore will update the posterior by reweighting alone, without retraining or resampling. The inferred radius of 12.6 km and tidal deformability of 469 at 1.4 solar masses reproduce Gaussian-process and heavy-ion-informed inferences despite a far broader prior. We find near-conformal but still stiff matter in the heaviest stars, consistent with a gradual hadron-quark crossover and disfavouring a strong first-order phase transition. More broadly, coupling a learned prior to exactly enforced physics establishes a template for ill-posed inverse problems where theory and data constrain different regions.
↳ nucl-thastro-ph.HEastro-ph.IMhep-ph+10 citations
31
Three-qubit entanglement in the Bethe-Heitler process
Haotian Cao🇺🇸 · Yuxun Guo🇺🇸 · Yoshitaka Hatta🇺🇸 · Jakob Schoenleber🇩🇪
The familiar Bethe-Heitler process on the proton target $e + p \to e + p + γ$ is transformed into a laboratory for studying multiparticle entanglement. We discuss how bipartite and genuine tripartite entanglement between the final state electron, proton and photon are built up by successive $1 \to 2$ and $2 \to 2$ elementary interactions. We validate our argument by simulating events. Below 5 GeV center-of-mass energy, we identify more than 900 Greenberger-Horne-Zeilinger (GHZ) states and 1200 W states, each with a fidelty exceeding 99%.
↳ quant-phhep-phnucl-th0 citations
32
Confining density functional approach to the QCD phase diagram at low temperatures and thermal twin stars
David Blaschke🇵🇱 · Oleksii Ivanytskyi🇵🇱
We present a density functional-based equation of state for warm, dense nuclear matter with a transition to deconfined quark matter for applications to simulations of supernova explosions and neutron star mergers, but also for the cosmological evolution of Q-balls. For the quark matter equation of state, we employ a recently developed confining density functional approach while nuclear matter is described within a relativistic density functional model of the DD2 class. The phase transition is obtained by a Maxwell construction at constant entropy per baryon. We discuss the solutions of TOV equations for isentropic hybrid stars for the hybrid equation of state model DDf-SFM (DD2- $χ$ CDF) without (with) color superconductivity and find that at finite temperatures above a critical value of entropy per baryon sequences of disconnected third family branches ("thermal twin stars") may appear for the DDf-SFM model, while they are absent for the color superconducting model and at $T = 0$ . We discuss the relation of this critical entropy per baryon to the Seidov criterion of gravitational instability for $T = 0$ and find that it is a good guide. We suggest that the presence of thermal twin stars may be regarded as an indicator for the core-collapse supernova explodability of massive blue supergiant stars and thus serve as a new criterion for the reliability of hybrid equation of state models. By this argument, strong color superconductivity shall be excluded and it remains to be shown whether models with moderate diquark pairing could fulfill the thermal twin constraint. For the case of symmetric matter, we compare the resulting hybrid EOS with the flow constraint by Danielewicz et al. and find a a sensitivity of the onset density for deconfinement on the presence or absence of color superconductivity.
↳ nucl-thastro-ph.SRhep-ph0 citations

Affiliations

first authorsco-authorsvia INSPIRE