Tue·Mar 25, 2025Tuesday·March 25, 2025

1. 01*

   Probing the general axion-nucleon interaction in water Cherenkov experiments

   Mael Cavan-Piton🇫🇷 · Diego Guadagnoli🇫🇷 · Axel Iohner🇫🇷 · Pablo Fernandez-Menendez🇪🇸 · Ludovico Vittorio🇫🇷

   We consider an axion flux on Earth consistent with emission from the Supernova explosion SN 1987A. Using Chiral Perturbation Theory augmented with an axion, we calculate the energy spectrum of $a+N\to N+\gamma$ as well as $a+N\to N+{\pi }^0$, where $N$ denotes a nucleon in a water tank, such as the one planned for the Hyper-Kamiokande neutrino detection facility. Our calculations assume the most general axion-quark interactions, with couplings constrained either solely by experimental data, or by specific theory scenarios. We find that even for the QCD axion -- whose interaction strength with matter is at its weakest as compared with axion-like particles -- the expected Čherenkov-light spectrum from neutrino-nucleon interactions is modified in a potentially detectable way. Furthermore, detectability appears significantly more promising for the $N+{\pi }^0$ final state, as its spectrum peaks an order of magnitude higher and at energies twice as large compared to the $N+\gamma$ counterpart. Given the rarity of SN events where both the neutrino and the hypothetical axion burst are detectable, we emphasize the importance of identifying additional mechanisms that could enhance such signals.

   hep-phastro-ph.HEJHEP(2025)·6 citations
2. 02*

   Higgs portal vector dark matter at a low reheating temperature

   Sarif Khan🇰🇷 · Jongkuk Kim🇰🇷 · Hyun Min Lee🇰🇷

   In this study, we explore vector dark matter (DM) production in the early Universe focusing on a scenario with a low reheating temperature. One can achieve low reheat temperature in many ways, for example, by considering a longer lifetime of the inflaton field. We analyze the impact of various model parameters on DM production, including gauge coupling and reheat temperature, while incorporating all relevant constraints from DM relic density, collider bounds, and DM direct and indirect detection experiments. Our results reveal a strong correlation between DM mass and reheat temperature, with viable parameter space requiring $T_R/M_{W_D}\sim 0.1$. While DM production from decays is generally subdominant, we identify a regime where freeze-in production from decay is dominant due to the phase space suppression. For DM masses below 100 GeV, production is primarily driven by SM fermions, whereas higher masses come due to the Higgses annihilation. The enhanced coupling strength in our framework enables potential detection in direct and indirect detection and collider experiments. The direct detection experiments have already explored some parts of the region and future DARWIN will explore the further region whereas for indirect detection, the detection prospects for the present case are futile. We found that a very narrow region of the parameter space has been explored by the DM direct detection contrary to the WIMP DM case where most of the parameter space has been ruled out.

   hep-phJCAP(2025)·17 citations
3. 03*

   High-precise determination of critical exponents in holographic QCD

   Fei Sun🇨🇳 · Xun Chen🇨🇳 · Shuang Li🇨🇳 · Akira Watanabe🇨🇳

   The precise determination of critical exponents is crucial for understanding the properties of strongly interacting matter under extreme conditions. These exponents are fundamentally linked to the system's behavior near the critical end point (CEP), making precise localization of the CEP essential. However, precisely identifying the CEP within the framework of AdS/CFT correspondence presents considerable challenges. In this study, we explore critical phenomena and critical exponents within a holographic QCD model. We achieve high-precision calculations of the CEP's position and dynamically analyze the behavior of the critical exponent as it approaches the CEP using limiting methods. Our results indicate that linear fitting is only appropriate in regions very close to the CEP. Furthermore, we find that although the values of the critical exponents vary when approaching the CEP from different directions, they ultimately converge to a single fixed value, revealing a universal behavior among these exponents. Our research underscores the importance of precisely determining the CEP, selecting the fitting region, and considering the direction of the approach when predicting critical exponents. These findings establish a vital benchmark for identifying critical phenomena and their associated exponents.

   hep-ph5 citations
4. 04*

   Lam-Tung relation breaking effects and weak dipole moments at lepton colliders

   Guanghui Li🇨🇳 · Xu Li🇮🇹 · Bin Yan🇨🇳

   The breaking of the Lam-Tung relation in the Drell-Yan process at the LHC exhibits a long-standing tension with the Standard Model (SM) prediction at $\mathcal{O}({\alpha }_s^3)$ accuracy. This tension could be explained by weak dipole interactions of leptons and quarks, associated with the $Z$-boson within the framework of the Standard Model Effective Field Theory (SMEFT). In this paper, we propose to cross-check these weak dipole interactions by measuring the violation effects of the Lam-Tung relation at future lepton colliders through the processes $e^{+}{e}^{-}\to Z\gamma \to \ell \bar{\ell }\gamma$ and $e^{+}{e}^{-}\to Z\gamma \to q\bar{q}\gamma$. By considering different decay modes of the $Z$-boson, these channels exhibit distinct sensitivities to various dipole operators, providing a way to disentangle their individual effects. Additionally, the high flavor-tagging efficiencies at lepton colliders could provide strong constraints on the dipole interactions of heavy quarks, such as $b$ and $c$ quarks, which are challenging to probe in the Drell-Yan process at the LHC due to the suppression of parton distribution functions.

   hep-phhep-exPLB(2025)·8 citations
5. 05*

   ${\eta }_c$ leading-twist distribution amplitude and the $B_c\to {\eta }_c\ell {\bar{\nu }}_{\ell }$ semileptonic decays using QCD Sum Rules

   Long Zeng🇨🇳 · Xing-Gang Wu🇨🇳 · Dan-Dan Hu🇨🇳 · Yu-Jie Zhang🇨🇳 · Hai-Bing Fu🇨🇳 · Tao Zhong🇨🇳

   In this paper, we investigate the semileptonic decays $B_c\to {\eta }_c\ell {\bar{\nu }}_{\ell }$ using the quantum chromodynamics(QCD) sum rules within the framework of Standard Model (SM). We further explore the potential to probe signatures of new Physics (NP) beyond the SM through these decays. First, we derive the $\xi$-moments $⟨{\xi }_{2;{\eta }_c}^n⟩$ of the ${\eta }_c$-meson leading-twist distribution amplitude ${\varphi }_{2;{\eta }_c}$ using the QCD sum rules within the background field theory. Considering contributions from the vacuum condensates up to dimension-six, the first two nonzero $\xi$-moments at the scale of $4$ GeV are found to be $⟨{\xi }_{2;{\eta }_c}^2⟩=0.103_{-0.009}^{+0.009}$ and $⟨{\xi }_{2;{\eta }_c}^4⟩=0.031_{-0.003}^{+0.003}$. Using these moments, we then fix the Gegenbauer expansion series of ${\varphi }_{2;{\eta }_c}$ and apply it to compute the $B_c\to {\eta }_c$ transition form factors (TFFs) using QCD light cone sum rules. Second, we extrapolate those TFFs to physically allowable $q^2$-range via a simplified series expansion, and we obtain $R_{{\eta }_c}{|}_{\mathrm{SM}}=0.308_{-0.062}^{+0.084}$. Furthermore, we explore the potential impacts of various NP scenarios on $R_{{\eta }_c}$. Specifically, we compute the forward-backward asymmetry ${\mathcal{A}}_{\mathrm{FB}}(q^2)$, the convexity parameter ${\mathcal{C}}_F^{\tau }(q^2)$, and the longitudinal and transverse polarizations ${\mathcal{P}}_L(q^2)$ and ${\mathcal{P}}_T(q^2)$ for $B_c\to {\eta }_c$ transitions within both the SM and two types of NP scenarios. Our results contribute to a deeper understanding of $B_c$-meson semileptonic decays and provide insights into the search for the NP beyond the SM.

   hep-phPRD(2025)·2 citations
6. 06*

   Search for doubly charmed dibaryons in baryon-baryon scattering

   Yao Cui🇨🇳 · Yuheng Wu🇨🇳 · Xinmei Zhu🇨🇳 · Hongxia Huang🇨🇳 · Jialin Ping🇨🇳

   We perform a systematical investigation of the doubly charmed dibaryon system with quantum numbers $IJ=01$, and strangeness numbers $S=0$, $-2$ and $-4$ in the framework of the chiral quark model. Two resonance states with strangeness numbers $S=-2$ is obtained in the $\Lambda {\Omega }_{cc}$ scattering channel, which are ${\Xi }_{cc}^{\ast }\Xi$ with resonance mass 5081 MeV and decay width 0.3 MeV, and the ${\Xi }_c{\Xi }_c^{\ast }$ state with the mass 5213 MeV and decay width 19.8 MeV, respectively. These two predicted charmed dibaryon candidates are worth searching for experimentally. Besides, we would like to emphasize that the multi-channel coupling calculation is important to confirm the existence of multiquark states. The coupling can shift the energy of the resonance, give the width to the resonance and even destroy the resonance. Therefore, to provide the necessary information for experiments to search for exotic hadron states, the coupling calculation between the bound channels and open channels is indispensable.

   hep-phhep-exhep-latnucl-thPRD(2025)·2 citations
7. 07*

   Chiral Anomaly Cancellation and Neutral Triple Gauge Boson Vertices in the SM EFT

   Dimitrios Beis🇬🇷 · Athanasios Dedes🇬🇷

   We demonstrate the cancellation of chiral anomalies in the Standard Model Effective Field Theory (SM EFT), achieved through by a consistent choice of loop momentum routing in triangle diagrams with dimension-6 operator insertions. By enforcing gauge invariance and Bose symmetry, we show that Goldstone boson contributions cancel anomalies arising from massive gauge boson vertices, preserving the consistency of the SM EFT. We compute neutral triple gauge boson vertices at one loop, revealing dominant contributions from dimension-6 operators at all energies below the EFT cutoff. A UV-complete anomaly-free model with a heavy vector-like electron validates our approach, illustrating how heavy fermion decoupling generates SM EFT operators while maintaining anomaly cancellation. Our results highlight the phenomenological relevance of these vertices for probing new physics at colliders, particularly through dimension-6 effects that scale as the inverse of the centre of mass energy squared, 1/s, offering a viable pathway for experimental detection.

   hep-phPRD(2025)·1 citation
8. 08*

   Phenomenology of Spin-1 resonances at the LH

   W. Porod🇩🇪

   Spin-1 resonances are among the states predicted by composite Higgs models and one expects them the have masses in the range of a few TeV. We focus here on models based on an underlying gauge-fermion description which predict QCD-coloured vector and axial-vector states as well as states charged under the electroweak gauge groups. The former can come as triplet, sextet and octet representation depending on the model details. All models considered have a colour octet vector state in common which can be singly produced at hadron colliders as it mixes with the gluon. We summarize here their LHC phenomenology and comment also on aspects relevant for future colliders.

   hep-phPoS(2025)·0 citations
9. 09*

   New physics from atmosphere: light sgoldstino case

   S.V. Demidov🇷🇺

   In a supersymmetric model with low scale supersymmetry breaking light sgoldstinos can appear in decays of mesons abundantly produced in atmospheric showers. We obtain bounds on parameter space of such a scenario from the Super-Kamiokande atmospheric neutrino oscillation data and estimate future sensitivity of the Hyper-Kamiokande project. We find that the bounds from the Super-Kamiokande results are weaker than constraints from existing searches by other experiments while the Hyper-Kamiokande detector can probe a still allowed part of the model parameter space.

   hep-phInt.J.Mod.Phys.A(2025)·1 citation
10. 10*

    Dynamical dark energy from an ultralight axion

    Hoang Nhan Luu🇪🇸 · Yu-Cheng Qiu🇨🇳 · S.-H. Henry Tye🇺🇸

    Recently the Dark Energy Survey (DES) Collaboration presented evidence that the equation of state $w$ of the dark energy is varying, or $w\simeq -0.948$ if it is constant. In either case, the dark energy cannot be due to a cosmological constant alone. Here we study an ultralight axion (or axion-like particle) with mass $m_{\varphi }\simeq 2\times 10^{-33}$ eV that has properties that can explain the new $w$ measurement. In particular, $w\ge -1$ and a negative cosmological constant $\Lambda <0$ is preferred in this model. We also present a simple formula for $w$ for the model to ease data fitting.

    hep-phastro-ph.COPRD(2025)·25 citations
11. 11*

    Gravitational Waves from Resonant Transitions of Tidally Perturbed Gravitational Atoms

    Antonios Kyriazis🇺🇸 · Fengwei Yang🇺🇸

    Light bosons can form a gravitational atom (GA) around a spinning black hole through the superradiance process. Considering the black hole to be part of a binary system, the tidal potential of the companion periodically perturbs the GA such that an ``atomic'' transition occurs between two of its energy eigenstates. The resonant transition is modeled by the Landau-Zener system, where the orbital frequency of the companion determines the relevant transition. In this work, we study a novel quasi-monochromatic gravitational wave signal originating directly from the level transition of the GA in a binary system. We derive the analytical formulae of both the strain waveform and frequency spectrum of the signal. We further investigate the GA-binary systems that can have a large signal-to-noise ratio in the milli-Hz to deci-Hz frequency band. Using the future space-based gravitational wave observatory DECIGO, we find the signal-to-noise ratio is $\mathcal{O}(10-200)$ for the fine-structure constant $\alpha \simeq 0.3$, host black hole mass $M=150M_{\odot }$ and boson mass $\mu \simeq 10^{-13}\mathrm{eV}$ at a distance within 100 kpc. Given astrophysical uncertainties about the black hole's initial spin, the degeneracy with other monochromatic signals and the small merger rate at those distances, we conclude that the detection of the signal would be challenging.

    hep-phastro-ph.COgr-qcJHEP(2025)·12 citations
12. 12*

    Open database for GPD analyses

    V.D. Burkert (1)🇺🇸 · A. Camsonne (1)🇺🇸 · P. Chatagnon (1 and 2)🇫🇷 · K. Cichy (3)🇵🇱 · M. Constantinou (4)🇺🇸 · H. Dutrieux (5)🇺🇸 · I. M. Higuera-Angulo (1)🇺🇸 · C. Mezrag (2)🇫🇷 · D. Richards (1)🇺🇸 · P. Sznajder (6) ((1) Thomas Jefferson National Accelerator Facility, Newport News, USA, (2) Irfu, CEA, Université Paris-Saclay, Gif-sur-Yvette, France, (3) Faculty of Physics and Astronomy, Adam Mickiewicz University, Poznań, Poland, (4) Department of Physics, Temple University, Philadelphia, Philadelphia, USA, (5) Physics Department, William & Mary, Williamsburg, USA, (6) National Centre for Nuclear Research, NCBJ, Warsaw, Poland)🇵🇱

    This article summarizes the main ideas behind creating an open database proposed for use in the exploration of generalized parton distributions (GPDs). This lightweight database is well suited for GPD phenomenology and is designed to store both experimental and lattice-QCD data. It can also aid in benchmarking GPD-related developments, such as GPD models. The database utilizes a new data format based on the YAML serialization language, enabling the storage of essential information for modern analyses, such as replica values. It includes interfaces for both Python and C++, allowing straightforward integration with analysis codes.

    hep-phEPJC(2025)·6 citations
13. 13*

    Scalable architecture for dark photon searches: Superconducting-qubit proof of principle

    Runqi Kang🇨🇳 · Qingqin Hu🇨🇳 · Xiao Cai🇨🇳 · Wenlong Yu🇨🇳 · Jingwei Zhou🇨🇳 · Xing Rong🇨🇳 · Jiangfeng Du🇨🇳

    The dark photon is a well-motivated candidate of dark matter due to its potential to open the window of new physics beyond the Standard Model. A fundamental mass-range-sensitivity dilemma is always haunting the dark photon searching experiments: The resonant haloscopes have excellent sensitivity but are narrowband, and vice versa for the non-resonant ones. A scalable architecture integrating numerous resonant haloscopes will be a desirable solution to this dilemma. However, even the concept of scalable searching remains rarely explored, due to the size limitation of conventional haloscopes imposed by the dark photon wavelength. Here we propose and demonstrate a novel architecture using superconducting qubits as sub-wavelength haloscope units. By virtue of the scalability of superconducting qubits, it is possible to integrate multiple qubits with different frequencies on a chip-scale device. Furthermore, the frequencies of the qubits can be tuned to extend the searching mass range. Thus, our architectures allow for searching for dark photons in a broad mass range with high sensitivity. As a proof-of-principle experiment, we designed and fabricated a three-qubit chip and successfully demonstrated a scalable dark-photon searching. Our work established constraints on dark photons in the mass range of 15.632 $\mu$eV$\sim$15.638 $\mu$eV, 15.838 $\mu$eV$\sim$15.845 $\mu$eV, and 16.463 $\mu$eV$\sim$16.468 $\mu$eV, simultaneously, and the constraints are much more stringent than the cosmology constraints. Our work can be scaled up in the future to boost the scrutiny of new physics and extended to search for more dark matter candidates, including dark photons, axions and axion-like particles.

    hep-phquant-phPRL(2025)·7 citations
14. 14*

    Magnetic Monopoles and Exotic States in $SU(4{)}_c\times SU(2{)}_L\times SU(2{)}_R$

    Thomas W. Kephart🇺🇸 · Qaisar Shafi🇺🇸

    In the Pati-Salam gauge symmetry $SU(4{)}_c\times SU(2{)}_L\times SU(2{)}_R$ (4-2-2, for short), the observed quarks and leptons of each family reside in the bi-fundamental representations $(4,2,1)$ and $(\bar{4},1,2)$. There exist, however, the fundamental representations $(4,1,1)$, $(1,2,1)$ and $(1,1,2)$ and their hermitian conjugates, which show the presence, in principle, of yet to be discovered color triplets that carry electric charge $\pm e/6$, and color singlet particles with charges of $\pm e/2$. These Standard Model charges are in full accord with the fact that the 4-2-2 model predicts the presence of a topologically stable finite energy magnetic monopole that carries two quanta of Dirac magnetic charge, i.e., $4\pi /e$, as well as color magnetic charge that is screened beyond the quark confinement scale. The 4-2-2 model therefore predicts the existence of exotic baryons, mesons and leptons that carry fractional ($\pm e/2$) electric charges. Since their origin lies in the fundamental representations of 4-2-2, these exotic particles may turn out to be relatively light, in the TeV mass range or so. The 4-2-2 magnetic monopole mass depends on the 4-2-2 symmetry breaking scale which may be as low as a few TeV.

    hep-phastro-ph.HEhep-thPRD(2025)·4 citations
15. 15*

    Finite-temperature effects on the threshold cusps in $\pi \pi$ and $D{\bar{D}}^{\ast }$ scatterings from relativistic heavy-ion collisions

    Ying Zhang🇨🇳 · Atsushi Hosaka🇯🇵 · Qian Wang🇨🇳 · Shigehiro Yasui🇯🇵

    We investigate how the temperature influences the threshold cusps in meson-meson scatterings, i.e., $\pi \pi$ and $D{\bar{D}}^{\ast }$ (or $D^{\ast }\bar{D}$) scatterings, using the production rates and propagators obtained at finite temperature. The lineshape of production rate of $\pi \pi$ at different temperatures demonstrates that the cusp structure in $\pi \pi$ scattering is mildly enhanced as the temperature increases. As for the $\pi \pi$ propagator, which includes the isospin symmetry breaking, its lineshape displays a unique plateau-like structure and this structure will also be enhanced as the temperature increases. For comparison, the lineshape of the $D{\bar{D}}^{\ast }$ propagator including the isospin symmetry breaking is also investigated at different temperatures. As the temperature increases, its lineshape shows a similar plateau-like structure but with some different properties when the temperature modifications to the masses and widths of $D$ and ${\bar{D}}^{\ast }$ are considered.

    hep-phPRC(2026)·0 citations
16. 16*

    Non-perturbative suppression of the Chiral Magnetic Effect in Quark Gluon Plasma

    Ruslan A. Abramchuk🇮🇱

    In this paper the non-perturbative suppression of the Chiral Magnetic Effect (CME) is investigated in the deconfined region of the QCD phase diagram (as a model for Quark-Gluon Plasma (QGP) emerging in Heavy Ion Collisions (HIC)), using the Kubo formula to calculate a linear response to the chiral imbalance, and the Field Correlator Method to address the strong interaction in QCD. The estimate suggests that CME is severely suppressed in most of the QCD phase diagram, except within a narrow strip at baryon densities above nuclear and temperatures just above the deconfinement transition. The result suggests refining the conditions under which the CME might be observable -- prioritizing the conditions at lower energy RHIC-BES, SPS and upcoming FAIR, NICA, J-PARC-HI, which supposedly produce high baryon density QGP, over the higher energy RHIC and LHC, which produce high temperature QGP.

    hep-phhep-exhep-lathep-th1 citation
17. 17*

    Isotropic cosmic birefringence from string axion domain walls without cosmic strings, and DESI results

    Junseok Lee🇯🇵 · Kai Murai🇯🇵 · Fuminobu Takahashi🇯🇵 · Wen Yin🇯🇵

    Recently, results from the Atacama Cosmology Telescope (ACT) DR6 have shown a preference for isotropic cosmic birefringence, consistent with previous analyses based on Planck and WMAP data. Separately, the Dark Energy Spectroscopic Instrument (DESI) DR2 results suggest that dark energy evolves over cosmic history, pointing to new physics in the late-time universe. In this paper, we propose that domain walls associated with the string axion can naturally explain the isotropic cosmic birefringence, focusing on the case in which the axion starts near a hilltop. Interestingly, to avoid the domain wall problem, these walls must form well after recombination. The predicted rotation angle, $\beta \approx 0.21c_{\gamma }$ degrees (with anomaly coefficient $c_{\gamma }\approx 1$), is in excellent agreement with observations. This scenario can be further tested by probing anisotropic birefringence of photons emitted long after recombination, as well as gravitational waves. Moreover, starting the axion oscillation from a hilltop naturally enhances its abundance via anharmonic effects, thus contributing to the dark energy component. We discuss how this hilltop axion scenario may connect with the DESI results.

    hep-phastro-ph.COPRD(2025)·30 citations
18. 18*

    Future Collider Measurements for Cosmic Ray Induced Air Shower Modelling

    Clara E. Leitgeb · Robert D. Parsons🇩🇪 · Andrew Taylor🇩🇪 · Kenneth Ragan🇨🇦 · David Berge🇩🇪 · Cigdem Issever

    The identification of gamma-ray induced air showers with Cherenkov telescopes suffers from contamination with a specific class of cosmic ray induced air showers. The predictions for this background show strong discrepancies between the available event generators. In this study, we identify collision events of cosmic rays with atmospheric nuclei in which a large fraction of the original beam energy is transmitted to the electromagnetic part of the shower as the main source for this background. Consequently, we define a pseudorapidity region of interest for hadron collider experiments that corresponds to this background, taking into account the center-of-mass energy. This region of interest is compared with the available datasets and the pseudorapidity coverage of the detectors that recorded it. We find that the LHCf and RHICf detectors are the only ones covering substantial parts of this region of interest and suggest a measurement of the energy spectra of reconstructed neutral pions to be made with this data. Such results could serve as valuable constraints for a future parameter tuning of the event generators to improve the background estimation uncertainties for gamma-ray induced air shower identification.

    hep-phastro-ph.HEastro-ph.IMActa Phys.Polon.Supp.(2025)·1 citation
19. 19*

    Dark Matter and Collider Phenomenology in Radiative Type-III Seesaw Model with Two Inert Doublets

    Tapender🇮🇳 · Labh Singh🇮🇳 · Surender Verma🇮🇳

    We investigate a minimal Type-III scotogenic model featuring two inert scalar doublets and a hyperchargeless triplet fermion. The scalar sector, in addition to the Standard Model Higgs, includes a rich spectrum of dark scalars comprising two CP-even, two CP-odd, and two charged states. This framework gives rise to two viable dark matter candidates: the lightest CP-even dark scalar and the neutral component of the triplet fermion. We perform a comprehensive analysis of both dark matter scenarios, carefully examining their viability under the umbrella of theoretical consistency conditions and experimental constraints. Beyond the conventional collider signatures anticipated in the Type-III scotogenic model with a single inert doublet, our extended framework predicts distinctive and novel signatures.

    hep-phPhys.Dark Univ.(2025)·2 citations
20. 20*

    Mixed CP Violation and Natural Alignment in 2HDMs

    Neda Darvishi🇬🇧 · Apostolos Pilaftsis🇬🇧

    We present a new form of CP violation (CPV) that can be realised in Two-Higgs Doublet Models (2HDMs) and was studied recently in [1]. By examining the vacuum manifold of a generic (convex) 2HDM potential, we identify scenarios that exhibit Mixed Spontaneous and Explicit CP Violation (MCPV), in which at least two non-degenerate CP-violating local minima coexist. We illustrate how this identification is achieved at the tree level by determining the magnitude and phase of a novel complex parameter, which we call $r_{\mathrm{CP}}$. Since explicit CP Violation vanishes in 2HDMs where SM Higgs alignment is enforced through global continuous symmetries, we investigate how to maximise CPV in such scenarios by introducing soft or explicit breaking of the relevant symmetries. In doing so, we derive upper bounds on key CP-violating parameters that characterise misalignment with the SM, subject to constraints from the non-observation of the electron electric dipole moment. Finally, we delineate the region of the CP-violating parameter space in such constrained 2HDMs that can be further tested at the CERN Large Hadron Collider.

    hep-phPoS(2025)·3 citations
21. 21*

    Constraints on $\Delta L=2$ Vector Bosons with Tree Couplings to SM Particles

    Zhong-Lv Huang🇨🇳 · Xiao-Gang He🇨🇳

    We investigate phenomenological implications of vector bosons $V$ transforming as (1, 2, -3/2) under the standard model (SM) product gauge group $SU(3{)}_C$, $SU(2{)}_L$ and $U(1{)}_Y$. These vector bosons can couple to two SM leptons at tree-level forming dimension-4 operators. These operators dictate $V$ to have two units of global lepton number, $\Delta L=2$. The operators generated conserve the global lepton number but can violate generational lepton numbers. We study constraints on the couplings $Y$ of $V$ to SM particles using tree-level processes such as $l_{\alpha }^{-}\to l_{\beta }^{+}{l}_{\rho }^{-}{l}_{\sigma }^{-}$, muonium and antimuonium oscillation, neutrino trident scattering, inverse muon decay, $e^{-}{e}^{+}\to l^{-}{l}^{+}$, and also one-loop level processes such as the magnetic dipole moment of a charged lepton and $l_i\to l_j\gamma$. Strong constraints are obtained from $l_{\alpha }^{-}\to l_{\beta }^{+}{l}_{\rho }^{-}{l}_{\sigma }^{-}$ with $\left|Y_{ee}{Y}_{\mu e}^{\ast }\right|<3.29\times 10^{-11}{\left(m_V/\mathrm{GeV}\right)}^2,\left|Y_{ee}{Y}_{e\mu }^{\ast }\right|<3.29\times 10^{-11}{\left(m_V/\mathrm{GeV}\right)}^2$ and from $l_i\to l_j\gamma$ with $\left|Y_{\tau e}{Y}_{\mu \tau }^{\ast }\right|<3.46\times 10^{-12}(m_V/\mathrm{GeV}{)}^2,\left|Y_{e\tau }{Y}_{\tau \mu }^{\ast }\right|<3.46\times 10^{-12}{\left(m_V/\mathrm{GeV}\right)}^2$, respectively. Interestingly, the imaginary part of the coupling constant in our model induces CP violation, which is constrained by experimental limits on the electric dipole moment.

    hep-phJHEP(2025)·4 citations
22. 22*

    Analysis of three-body hadronic $D$-meson decays

    Xu-Da Zhou🇨🇳 · Si-Hong Zhou🇨🇳

    Motivated by recent experimental advances in three-body hadronic $D$ decays from BESIII, we present a systematic analysis of $D_{(s)}\to P_1(V\to )P_2{P}_3$ decay processes, where $V$ denotes vector resonances ($\rho ,K^{\ast },\omega$, $\varphi$) and $P_{1,2,3}$ are light pseudoscalar mesons ($\pi ,K,{\eta }^{(\prime )}$). Using the factorization-assisted topological-amplitude (FAT) approach we calculate the intermediate subprocesses $D_{(s)}\to P_{1}V$, incorporating relativistic Breit-Wigner distributions to model the subsequent $V\to P_2{P}_3$ strong decays. By comprehensively including all relevant resonances ($\rho ,K^{\ast },\omega ,\varphi$), we calculate branching fractions for these decay modes as well as the Breit-Wigner-tail effects in $D_{(s)}\to P_1(\omega \to )KK$ processes. Our framework comprehensively incorporates both factorizable and nonfactorizable contributions, significantly improving theoretical predictions in the nonperturbative regime where conventional methods face challenges due to the limited mass scale of charm mesons. The FAT approach yields results in good agreement with experimental data, demonstrating its effectiveness in capturing nonfactorizable contributions with improved precision. Our predictions for yet-unobserved decay modes, particularly those with branching fractions in the order of $10^{-4}$ to $10^{-3}$, are expected to be tested in future high-precision experiments at BESIII and LHCb.

    hep-phPRD(2025)·4 citations
23. 23*

    QCD sum rules study on weak decays ${\Omega }_c^0\to {\Omega }^{-}({\pi }^{+},{\rho }^{+},l^{+}{\nu }_l)$

    Yu-Ji Shi🇨🇳 · Jun Zeng🇨🇳

    We study the weak decays of the charmed baryon ${\Omega }_c^0$ to the ${\Omega }^{-}$ baryon within the framework of QCD sum rules. A three-point correlation function is defined for calculating eight form factors governing the ${\Omega }_c^0\to {\Omega }^{-}$ transition. The cutting rules are employed to extract the double imaginary parts of the correlation functions, enabling their expression in the form of dispersive integrals. These form factors are then used to determine the branching fractions for the hadronic decays ${\Omega }_c^0\to {\Omega }^{-}{\pi }^{+}$ and ${\Omega }_c^0\to {\Omega }^{-}{\rho }^{+}$, as well as the semi-leptonic decay ${\Omega }_c^0\to {\Omega }^{-}{\ell }^{+}{\nu }_{\ell }$. Our results are compared with existing theoretical predictions and experimental data, providing a comprehensive analysis of ${\Omega }_c^0$ decays and offering valuable insights into the dynamics of charmed baryon decays.

    hep-phhep-exEPJC(2025)·3 citations
24. 24*

    No-scale Brans-Dicke Gravity -- ultralight scalar boson & heavy inflaton

    Muzi Hong🇯🇵 · Kyohei Mukaida🇯🇵 · Tsutomu T. Yanagida🇯🇵

    It is very much intriguing if the Planck scale $M_{\mathrm{Pl}}$ is not a fundamental parameter. The Brans-Dicke gravity is nothing but the theory where the Planck scale $M_{\mathrm{Pl}}$ is indeed an illusional parameter. The theory predicts a massless scalar boson whose exchanges between matters induce unwanted long range forces. We solve this problem imposing there is no dimensionful parameter in the theory, even at the quantum level. We further extend the theory by including a $R^2$ term and a non-minimal coupling of the Standard Model Higgs to gravity, as their coefficients are dimensionless. This extension provides a heavy inflaton field that is consistent with all cosmological observations, with a potential very similar to that of the Starobinsky model. The inflaton necessarily decays into the massless scalar bosons, resulting in a non-negligible amount of dark radiation in the present universe. We demonstrate that the inflation model yields a sufficiently high reheating temperature for successful leptogenesis, and we also discuss a possible candidate for dark matter.

    hep-phastro-ph.COgr-qchep-thJCAP(2025)·7 citations
25. 25*

    Probing Pion Valence Quark Distribution with Beam-charge Asymmetry of Pion-induced $J/\psi$ Production

    Wen-Chen Chang🇹🇼 · Marco Meyer-Conde🇯🇵 · Jen-Chieh Peng🇺🇸 · Stephane Platchkov🇫🇷 · Takahiro Sawada🇯🇵

    We consider the beam-charge asymmetry of the $J/\psi$ production cross sections in ${\pi }^{-}$- versus ${\pi }^{+}$-induced reactions on proton or nuclear targets. We show that the $J/\psi$ production cross section difference between ${\pi }^{-}$ and ${\pi }^{+}$ beams impinging on a proton target has a positive sign with a magnitude proportional to the product of pion's valence quark distribution, $V_{\pi }$, and proton's up and down valence quark distribution difference, $u^V-d^V$. The existing $J/\psi$ production data for ${\pi }^{-}+p$ and ${\pi }^{+}+p$ at 39.5 and 200 GeV/c are consistent with the expected positive beam-charge asymmetry. The magnitude of the asymmetry is compared with calculations performed within two theoretical frameworks, the Color Evaporation Model (CEM) and the Non-Relativistic QCD (NRQCD) formalism. We also examine the beam-charge dependence for pion-induced $J/\psi$ production cross sections measured on the neutron-rich platinum target, and find good agreement between the data and theory for both the negative sign and the magnitude of the beam-charge asymmetry. The comparison between data and theoretical calculations for both proton and platinum targets suggests that the beam-charge asymmetry in pion-induced $J/\psi$ production is a viable method of accessing the valence quark distribution of the pion.

    hep-phhep-exnucl-exPLB(2025)·1 citation
26. 26*

    Higher Axion Strings

    Vazha Loladze🇬🇧 · Arthur Platschorre🇬🇧 · Mario Reig🇬🇧

    We study the minimal requirements to obtain axion strings for axions with exponentially good quality. These ingredients appear in theories where an axion coming from a higher-form gauge field mixes with the phase of a complex scalar field in a situation that resembles higher-groups. The resulting axion is perturbatively massless and inherits a high-quality shift symmetry from the global higher-form symmetry while being compatible with a post-inflationary axion scenario. Due to differences and resemblances with both, extra-dimensional and field theory axions, we call this field the higher axion. To this end, we study a toy model on a 5-dimensional manifold with boundary. The boundary hosts the complex scalar that provides axion strings through standard mechanisms. In addition, we study how these scenarios may arise in heterotic string theory and type II string compactifications.

    hep-phJHEP(2025)·24 citations
27. 27*

    Femtoscopy correlation functions and hadron-hadron scattering amplitudes in presence of Coulomb potential

    M. Albaladejo🇪🇸 · A. Garcia-Lorenzo🇪🇸 · J. Nieves🇪🇸

    This work addresses the incorporation of Coulomb interactions into femtoscopy correlation functions (CFs) used to probe hadron interactions. Combining strong contact potentials with Coulomb effects, the derived scattering amplitudes and wave functions are used to compute CFs, accounting for both interactions coherently. Next, we analyze the nature of the corrections due to the finite range of the strong interaction, closely linked to off-shell effects, and propose an approximate method to account for them. We show how these corrections turn out to be essential to accurately extract the strong hadron-hadron scattering amplitudes from CF data. We compare the obtained expressions for the CFs with those reported in previous theoretical frameworks. Also, using proton-proton systems as a case study, we obtain a good comparison of our results with previous realistic theoretical calculations and with accurate recent data from the ALICE experiment. The framework enables precise CF calculations without numerical solution of the Schrödinger equation, offering a practical tool for femtoscopy analyses involving charged hadrons. In addition, the scheme allows for an easy connection with scattering amplitudes obtained from Effective Field Theories.

    hep-phnucl-thPTEP(2025)·9 citations
28. 28*

    A detailed study on the prospects for a $\mathrm{t}\overline{\mathrm{t}}$ threshold scan in ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$ collisions

    Matteo M. Defranchis🇨🇭 · Jorge de Blas🇪🇸 · Ankita Mehta🇨🇭 · Michele Selvaggi🇨🇭 · Marcel Vos🇪🇸

    A scan of the beam energy across the top quark pair ($\mathrm{t}\overline{\mathrm{t}}$) production threshold is part of the program of future Higgs, top, and electroweak factory projects. In this paper, we provide projections for the achievable precision in the top quark mass ($m_{\mathrm{t}}$), width (${\Gamma }_{\mathrm{t}}$), and Yukawa coupling ($y_{\mathrm{t}}$) at the electron-positron (${\mathrm{e}}^{+}{\mathrm{e}}^{-}$) stage of the Future Circular Collider (FCC-ee). The study includes a detailed assessment of parametric and systematic uncertainties, as well as a rigorous estimate of the effect of point-to-point correlations. We project that $m_{\mathrm{t}}$ and ${\Gamma }_{\mathrm{t}}$ can be determined with an experimental precision of about 6.8 and 11.5 MeV, respectively, when $m_{\mathrm{t}}$ is defined in the potential-subtracted (PS) scheme. The impact of theoretical uncertainties due to missing higher orders is found to be of about 35 (25) MeV on $m_{\mathrm{t}}$ (${\Gamma }_{\mathrm{t}}$) at N${}^3$LO in non-relativistic QCD. Therefore, improvements in the theoretical accuracy, which is an active area of development, are key to match the achievable experimental precision at a future ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$ collider. Finally, we explore the prospects for a measurement of $y_{\mathrm{t}}$ at FCC-ee via a dedicated run above the $\mathrm{t}\overline{\mathrm{t}}$ production threshold.

    hep-phhep-exJHEP(2025)·17 citations
29. 29*

    Superheavy Supersymmetric Dark Matter for the origin of KM3NeT Ultra-High Energy signal

    Yongsoo Jho🇰🇷 · Seong Chan Park🇰🇷 · Chang Sub Shin🇰🇷

    We propose an explanation for the recently reported ultra-high-energy neutrino signal at KM3NeT, which shows no clear association with known astrophysical sources. While decaying dark matter in the Galactic Center is a natural candidate, the observed arrival direction strongly suggests an extragalactic origin. We introduce a multicomponent dark matter scenario in which the components are part of a supermultiplet, with supersymmetry ensuring a nearly degenerate mass spectrum among the fields with different spins. In this setup, a cosmologically long-lived fermionic state decays into a slightly lighter bosonic dark matter state, producing a boosted neutrino spectrum with energy $E_{\nu }\sim 100$ PeV, determined by the mass difference. The heavy-to-light decay occurs at a cosmological redshift of $z\sim \text{a few}$ or higher, leading to an isotropic directional distribution of the signal.

    hep-phastro-ph.HEPRD(2025)·22 citations
30. 30*

    Gravitational form factor of the kaon in holographic QCD

    Zhibo Liu🇯🇵 · Akira Watanabe🇨🇳

    The gravitational form factor (GFF) of the kaon is investigated in a bottom-up holographic QCD model, in which the strange quark mass breaks the SU(3) flavor symmetry. The probe energy ($Q^2$) dependence of the kaon GFF is explicitly shown and compared to that of the pion. It is presented that our result shows the $1/Q^2$ behavior in the high energy region, which is consistent with the perturbative QCD prediction. The gravitational radius of the kaon is also calculated, and it is found that the result is quite close to that of the pion but slightly smaller.

    hep-phnucl-thPRD(2025)·9 citations
31. 31*

    QCD corrections for subleading powers in $1/m_b$ for the nonleptonic $b\to c\bar{c}s$ transition

    Thomas Mannel🇩🇪 · Daniel Moreno🇨🇭 · Alexei A. Pivovarov🇩🇪

    We compute next-to-leading order QCD corrections to the $1/m_b^2$ terms of the Heavy Quark Expansion for the contribution to inclusive nonleptonic bottom hadron decays induced by the charged-current operators mediating the transitions $b\to c\bar{c}q$ ($q=s,d$). Their contributions to lifetimes are Cabibbo favoured and have large Wilson coefficents, but have not been computed before, since the presence of two heavy quarks in the final state makes this calcuation technically demanding. It finally adds the last missing piece of the full NLO terms at $1/m_b^2$ in the heavy quark expansion of $B$-hadron lifetimes. We obtain analytical results with full dependence on the final-state charm quark mass, which we provide in the supplemental file "coefbccs.m".

    hep-phPRD(2025)·9 citations
32. 32*

    Dark matter induced by neutrino mixing and flavor vacuum condensate probed by neutrino capture on tritium

    Antonio Capolupo🇮🇹 · Simone Monda🇮🇹 · Gabriele Pisacane🇮🇹 · Raoul Serao🇮🇹 · Aniello Quaranta🇮🇹

    We show that experiments designed to capture low energy neutrinos, like PTOLEMY are sensitive to the specific neutrino model. In particular, they might show a signature of the condensed flavor vacuum, featured in the flavor Fock space model, and allow to test the hypothesis according to which a possible dark matter component is determined by neutrino mixing.

    hep-phJ.Phys.Conf.Ser.(2025)·2 citations
33. 33*

    Warm Inflation with the Standard Model

    Kim V. Berghaus🇺🇸 · Marco Drewes🇧🇪 · Sebastian Zell🇧🇪

    We show for the first time that warm inflation is feasible with Standard Model (SM) gauge interactions alone. Our model consists of a minimal extension of the SM by a single scalar inflaton field with an axion-like coupling to gluons and a monomial potential. The effects of light fermions, which were previously argued to render warm inflation with the SM impossible, are alleviated by Hubble dilution of their chiral chemical potentials. Our model only features one adjustable combination of parameters and accommodates all inflationary observables. We briefly discuss implications for axion experiments, dark matter, and the strong CP-problem.

    hep-phastro-ph.COPRL(2025)·42 citations
34. 34*

    Higher-dimensional operators at finite-temperature affect gravitational-wave predictions

    Fabio Bernardo🇨🇭 · Philipp Klose🇨🇭 · Philipp Schicho🇨🇭 · Tuomas V. I. Tenkanen🇫🇮

    We investigate the effect of higher-dimensional marginal operators on the thermodynamics of cosmological phase transitions. Using the Abelian Higgs model as a representative for radiatively-generated one-step transitions, we systematically match these operators, which arise at higher orders in the underlying high-temperature expansion of thermal effective field theory, and use field redefinitions to construct a complete, minimal, and gauge-invariant operator basis. The Abelian Higgs model shares the essential infrared structure of more realistic gauge-Higgs theories at high temperatures, allowing us to test the validity of dimensional reduction in a simplified setting. We argue that for strong transitions, temporal gauge modes, which enhance the transition strength, should be treated on equal footing with spatial ones. Marginal operators are found to weaken the transition and introduce significant uncertainties for strong transitions. For transitions strong enough to produce gravitational waves detectable by LISA, our findings suggest that the high-temperature expansion may break down entirely. This would limit the applicability of effective theory techniques, including their use in non-perturbative lattice studies.

    hep-phJHEP(2025)·39 citations
35. 35*

    Observing Dark Matter Decays to Gravitons via Graviton-Photon Conversion

    David I. Dunsky🇺🇸 · Gordan Krnjaic🇺🇸 · Elena Pinetti🇺🇸

    Since dark matter is only known to have gravitational interactions, it may plausibly decay to gravitons on cosmological timescales. Although such a scenario can be easily realized, there are currently no known limits on this possibility based on indirect detection searches. We find that the gravitons produced in dark matter decays can convert to photons in large-scale magnetic fields along the line of sight to an observer. These conversions primarily occur within cosmological filaments which occupy a large (order unity) volume fraction and contain $\sim 10-100$ nG fields with $\sim$ Mpc coherence lengths. Thus, dark matter decays to gravitons predict an irreducible population of extragalactic $\text{photons}$, which we constrain using the extragalactic gamma-ray background measured by the $\text{Fermi}$-LAT telescope. Using this conservative method, we place the first limits on the dark matter lifetime in the $0.1\mathrm{GeV}-10^8$ GeV mass range, assuming only decays to gravitons. We also make projections for the Advanced Particle-astrophysics Telescope, which can improve sensitivity to this DM decay channel by an order of magnitude beyond those we set using $\text{Fermi}$-LAT data.

    hep-phastro-ph.COPRD(2026)·8 citations
36. 36*

    Anisotropic pressure and novel first-order phase transition in SU(3) Yang-Mills theory on ${\mathbb{T}}^2\times {\mathbb{R}}^2$

    Daisuke Fujii🇯🇵 · Akihiro Iwanaka🇯🇵 · Masakiyo Kitazawa🇯🇵 · Daiki Suenaga🇯🇵

    We investigate the thermodynamic behavior and phase diagram of $SU(3)$ Yang-Mills theory on ${\mathbb{T}}^2\times {\mathbb{R}}^2$ in Euclidean spacetime using an effective model. In our approach, the Polyakov loops along the compactified directions are treated as dynamic variables, and the model is calibrated to match lattice simulation results for thermodynamic observables on ${\mathbb{T}}^2\times {\mathbb{R}}^2$. Our analysis reveals a novel first-order phase transition in the deconfined phase that ends at critical points, which appear to belong to the two-dimensional $Z_2$ universality class. This transition is driven by the interplay between the two Polyakov loops, introduced via a cross-term in the Polyakov-loop potential.

    hep-phhep-lathep-th0 citations
37. 37*

    Impact of new invisible particles on $B\to K^{(\ast )}{E}_{\mathrm{miss}}$ observables

    Patrick D. Bolton🇸🇮 · Svjetlana Fajfer🇸🇮 · Jernej F. Kamenik🇸🇮 · Martín Novoa-Brunet🇪🇸

    Motivated by a recent Belle~II measurement that suggests an excess in the rare decay $B\to K{E}_{\mathrm{miss}}$, and building upon our recent differential decay rate likelihood analysis of the existing experimental information, we investigate possible new physics (NP) scenarios in which light invisible states participate in flavour-changing $b\to s$ transitions. In particular, we consider the total and differential $B\to K^{\ast }{E}_{\mathrm{miss}}$ decay rates and $K^{\ast }$ polarisation effects in each NP scenario preferred by the $B\to K{E}_{\mathrm{miss}}$ measurement. We show that future measurements of these $B\to K^{\ast }{E}_{\mathrm{miss}}$ observables will offer decisive discrimination among the different NP explanations. Our results highlight the strong complementarity of the rare semi-invisible $b$-hadron decay observables, and underline the importance of analysing their momentum transfer spectra when probing extensions of the Standard Model that feature new light degrees of freedom.

    hep-phhep-exPRD(2025)·23 citations
38. 38*

    Minimal renormalizable $SO(10)$, spontaneous CP violation, and flavor implications

    Xiyuan Gao🇩🇪

    In these proceedings, we summarize our recent findings on a minimal renormalizable $SO(10)$ grand unified theory. With the assumption of spontaneous $CP$ violation, the low-energy theory becomes a constrained two-Higgs-doublet model, whose mass spectrum has an upper bound of 545 GeV. High-luminosity collider experiments may find its flavor violating signals and reveal hidden mixing parameters, enabling new predictions for proton decay. There is a possibility that a hint of minimal $SO(10)$ can appear soon in near future experiments.

    hep-phhep-exPoS(2025)·0 citations
39. 39*

    Cross section Measurements for ${}^{12}$C$(K^{-},K^{+}{\Xi }^{-})$ and ${}^{12}$C$(K^{-},K^{+}\Lambda \Lambda )$ Reactions at 1.8 GeV$/c$

    Woo Seung Jung🇰🇷 · Yudai Ichikawa🇯🇵 · Byung Min Kang🇰🇷 · Jung Keun Ahn🇰🇷 · Sung Wook Choi🇰🇷 · Manami Fujita🇯🇵 · Takeshi Harada🇯🇵 · Shoichi Hasegawa🇯🇵 · Shuhei Hayakawa🇯🇵 · Sang Hoon Hwang🇰🇷 · Kenneth Hicks🇺🇸 · Ken'ichi Imai🇯🇵 and 21 other authors

    We present a measurement of the production of ${\Xi }^{-}$ and $\Lambda \Lambda$ in the ${}^{12}$C$(K^{-},K^{+})$ reaction at an incident beam momentum of 1.8 GeV/$c$, based on high-statistics data from J-PARC E42. The cross section for the ${}^{12}$C$(K^{-},K^{+}{\Xi }^{-})$ reaction, compared to the inclusive ${}^{12}$C$(K^{-},K^{+})$ reaction cross section, indicates that the ${\Xi }^{-}$ escaping probability peaks at 70\% in the energy region of $E_{\Xi }=$100 to 150 MeV above the ${\Xi }^{-}$ emission threshold. A classical approach using eikonal approximation shows that the total cross sections for ${\Xi }^{-}$ inelastic scattering ranges between 42 mb and 23 mb in the ${\Xi }^{-}$ momentum range from 0.4 to 0.6 GeV/c. Furthermore, based on the relative cross section for the ${}^{12}$C$(K^{-},K^{+}\Lambda \Lambda )$ reaction, the total cross section for ${\Xi }^{-}p\to \Lambda \Lambda$ is estimated in the same approach to vary between 2.2 mb and 1.0 mb in the momentum range of 0.40 to 0.65 GeV/c. Specifically, a cross section of 1.0 mb in the momentum range of 0.5 to 0.6 GeV/c imposes a constraint on the upper bound of the decay width of the ${\Xi }^{-}$ particle in infinite nuclear matter, revealing ${\Gamma }_{\Xi }<\sim 0.6$ MeV.

    ↳ nucl-exhep-phPTEP(2025)·3 citations
40. 40*

    Stochastic origin of primordial fluctuations in the Sky

    Sayantan Choudhury🇵🇱

    We provide a study of the effects of the Effective Field Theory (EFT) generalisation of stochastic inflation on the production of primordial black holes (PBHs) in a model-independent single-field context. We demonstrate how the scalar perturbations' Infra-Red (IR) contributions and the emerging Fokker-Planck equation driving the probability distribution characterise the Langevin equations for the ``soft" modes in the quasi-de Sitter background. Both the classical-drift and quantum-diffusion-dominated regimes undergo a specific analysis of the distribution function using the stochastic-$\delta N$ formalism, which helps us to evade a no-go theorem on the PBH mass. Using the EFT-induced alterations, we evaluate the local non-Gaussian parameters in the drift-dominated limit.

    ↳ gr-qcastro-ph.COhep-phhep-thInt.J.Mod.Phys.D(2025)·14 citations
41. 41*

    Measurements of the branching fractions of ${\Xi }_c^{+}\to {\Sigma }^{+}{K}_S^0$, ${\Xi }_c^{+}\to {\Xi }^0{\pi }^{+}$, and ${\Xi }_c^{+}\to {\Xi }^0{K}^{+}$ at Belle and Belle II

    Belle · Belle II Collaborations: I. Adachi · J. K. Ahn · Y. Ahn · N. Akopov · S. Alghamdi · M. Alhakami · N. Althubiti · K. Amos · N. Anh Ky · C. Antonioli · D. M. Asner and 346 other authors

    Using 983.0 ${\mathrm{fb}}^{-1}$ and 427.9 ${\mathrm{fb}}^{-1}$ data samples collected with the Belle and Belle II detectors at the KEKB and SuperKEKB asymmetric energy $e^{+}{e}^{-}$ colliders, respectively, we present studies of the Cabibbo-favored ${\Xi }_c^{+}$ decays ${\Xi }_c^{+}\to {\Sigma }^{+}{K}_S^0$ and ${\Xi }_c^{+}\to {\Xi }^0{\pi }^{+}$, and the singly Cabibbo-suppressed decay ${\Xi }_c^{+}\to {\Xi }^0{K}^{+}$. The ratios of branching fractions of ${\Xi }_c^{+}\to {\Sigma }^{+}{K}_S^0$ and ${\Xi }_c^{+}\to {\Xi }^0{K}^{+}$ relative to that of ${\Xi }_c^{+}\to {\Xi }^{-}{\pi }^{+}{\pi }^{+}$ are measured for the first time, while the ratio $\mathcal{B}({\Xi }_c^{+}\to {\Xi }^0{\pi }^{+})/\mathcal{B}({\Xi }_c^{+}\to {\Xi }^{-}{\pi }^{+}{\pi }^{+})$ is also determined and improved by an order of magnitude in precision. The measured branching fraction ratios are $\frac{\mathcal{B}({\Xi }_c^{+}\to {\Sigma }^{+}{\mathcal{K}}_{\mathcal{S}}^0)}{\mathcal{B}({\Xi }_c^{+}\to {\Xi }^{-}{\pi }^{+}{\pi }^{+})}=0.067\pm 0.007\pm 0.003$, $\frac{\mathcal{B}({\Xi }_c^{+}\to {\Xi }^0{\pi }^{+})}{\mathcal{B}({\Xi }_c^{+}\to {\Xi }^{-}{\pi }^{+}{\pi }^{+})}=0.251\pm 0.005\pm 0.010$, $\frac{\mathcal{B}({\Xi }_c^{+}\to {\Xi }^0{\mathcal{K}}^{+})}{\mathcal{B}({\Xi }_c^{+}\to {\Xi }^{-}{\pi }^{+}{\pi }^{+})}=0.017\pm 0.003\pm 0.001$. Additionally, the ratio $\mathcal{B}({\Xi }_c^{+}\to {\Xi }^0{K}^{+})/\mathcal{B}({\Xi }_c^{+}\to {\Xi }^0{\pi }^{+})$ is measured to be $0.068\pm 0.010\pm 0.004$. Here, the first and second uncertainties are statistical and systematic, respectively. Multiplying the ratios by the branching fraction of the normalization mode, $\mathcal{B}({\Xi }_c^{+}\to {\Xi }^{-}{\pi }^{+}{\pi }^{+})=(2.9\pm 1.3)\%$, we obtain the following absolute branching fractions $\mathcal{B}({\Xi }_c^{+}\to {\Sigma }^{+}{K}_S^0)=(0.194\pm 0.021\pm 0.009\pm 0.087)$, $\mathcal{B}({\Xi }_c^{+}\to {\Xi }^0{\pi }^{+})=(0.728\pm 0.014\pm 0.027\pm 0.326)$, $\mathcal{B}({\Xi }_c^{+}\to {\Xi }^0{K}^{+})=(0.049\pm 0.007\pm 0.003\pm 0.022)$.

    ↳ hep-exhep-phJHEP(2025)·7 citations
42. 42*

    Why the DESI Results Should Not Be A Surprise

    Robert Brandenberger (McGill University)🇨🇦

    The recent DESI results provide increasing evidence that the density of dark energy is time-dependent. I will recall why, from the point of view of fundamental theory,, this result should not be surprising.

    ↳ astro-ph.COgr-qchep-phhep-th28 citations
43. 43*

    The Large Hadron electron Collider as a bridge project for CERN

    F. Ahmadova🇩🇪 · K. André🇨🇭 · N. Armesto🇪🇸 · G. Azuelos🇨🇦 · O. Behnke🇩🇪 · M. Boonekamp🇫🇷 · M. Bonvini🇮🇹 · D. Britzger🇩🇪 · O. Brüning🇨🇭 · T. A. Bud🇨🇭 · A. M. Cooper-Sarkar🇬🇧 · J. D'Hondt🇳🇱 and 30 other authors

    The LHeC is the project for delivering electron-nucleon collisions at CERN using the HL-LHC beams. An Energy Recovery Linac in racetrack configuration will provide 50 GeV electrons to achieve centre-of-mass energies around 1 TeV/nucleon and instantaneous luminosities around $10^{34}$ cm${}^{-2}$s${}^{-1}$. The LHeC program elaborated in the CDR of 2021 included a phase with concurrent operation of electron-hadron and hadron-hadron collisions, followed by a standalone phase of electron-hadron collisions only. In view of the current HL-LHC schedule, in this paper we have examined the possibilities of a program after the regular HL-LHC program with only electron-proton operation. In this operation mode, the LHeC would serve as an impactful bridge project between major colliders at CERN. The standalone physics program comprises electroweak, Higgs, top-quark, BSM and strong-interaction physics. In addition, it empowers the physics analyses at the HL-LHC by retrofitting measurements and searches with significantly more precise knowledge of the proton structure and ${\alpha }_s$. The accelerator technology deployed in the Energy Recovery Linac for the LHeC is a major stepping-stone for the performance, cost reduction and training for future colliders. The capital investments in the LHeC electron accelerator can be reused in a cost-efficient way as the injector for the FCC-ee. Finally, data from the LHeC are essential to enable the physics potential of any new high-energy hadron collider. The operational plan of 6 years easily fits in the period between two major colliders at CERN. Similar to the LHeC empowering the HL-LHC physics program, the FCC-eh would be an impactful addition to the FCC physics program.

    ↳ hep-exhep-ph17 citations
44. 44*

    Strongly Coupled Sectors in Inflation: Gapless Theories and Unparticles

    Guilherme L. Pimentel🇮🇹 · Chen Yang🇮🇹

    We compute correlation functions of the primordial density perturbations when they couple to a gapless, strongly coupled sector of spectator fields -- ``unparticles" -- during inflation. We first derive a four-point function of conformally coupled scalars for all kinematic configurations in de Sitter, which exchanges an unparticle at tree-level, by performing direct integration using the Mellin-Barnes method. To obtain inflationary bispectra and trispectra, we apply weight-shifting operators to the conformally coupled scalar correlator. We show that the correlators solve differential equations determined by the additional symmetries enjoyed by the unparticle propagator. Based on these differential equations, we are able to discuss the spinning-unparticle exchanges, focusing on two possible cases where the currents or the stress tensor of unparticles are coupled to inflatons, with the help of spin-raising operators. Finally, we study the phenomenology of the resulting shape functions. Depending on the value of the unparticle scaling dimension, we classify three characteristic shapes for the inflationary bispectra, including near-equilateral, near-orthogonal, and a novel shape which appears when the scaling dimensions are close to half-integers. More generally, we find that the leading order squeezed limits are insufficient to conclusively determine the detection of a light particle or unparticle. Only the full shapes of bispectra and trispectra can break this degeneracy.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2026)·29 citations
45. 45*

    Charge-dependent nucleon-nucleon interaction at N${}^3$LO in nuclear lattice effective field theory

    Chengxin Wu🇨🇳 · Teng Wang🇨🇳 · Bing-Nan Lu🇨🇳 · Ning Li🇨🇳

    The nuclear lattice effective field theory (NLEFT) is an efficient tool for solving nuclear many-body problems, which takes high-fidelity lattice chiral interactions as input and computes nuclear low-energy observables via quantum Monte Carlo techniques. In this work, we present the first next-to-next-to-next-to-leading order (N${}^3$LO) chiral forces on the lattice with the isospin-breaking effects fully taken into account. We focus on both the charge-independence breaking (CIB) and charge-symmetry breaking (CSB) effects. Specifically, we include the isospin-breaking effect from the mass difference between the charged and neutral pions in the one-pion-exchange potential (OPEP), the Coulomb force for the $pp$ interaction and the contribution of two additional charge-dependent contact operators. We also explicitly incorporate the two-pion-exchange potentials which was mostly neglected in previous NLEFT calculations. With these improvements, we are able to accurately reproduce the $np$ and $pp$ scattering phase shifts up to relative momentum $p\sim 200$ MeV as well as the deuteron properties. The construction of these charge-dependent lattice nuclear forces establishes a solid foundation for future high-precision nuclear ab initio calculations within the NLEFT framework.

    ↳ nucl-thhep-lathep-phnucl-exPRC(2025)·7 citations
46. 46*

    Asymptotic states of fast neutrino-flavor conversions in the three-flavor framework

    Jiabao Liu🇯🇵 · Hiroki Nagakura🇯🇵 · Masamichi Zaizen🇯🇵 · Lucas Johns🇺🇸 · Shoichi Yamada🇯🇵

    There has been growing evidence that mu and tau neutrinos are noticeably different due to the emergence of muons in core-collapse supernovae (CCSNe) and binary neutron star mergers (BNSMs). Recent theoretical studies also suggest that all flavors of neutrinos and antineutrinos inevitably experience some flavor mixing instabilities including fast neutrino flavor conversions (FFC), which corresponds to one of the collective neutrino oscillations powered by neutrino self-interactions. This represents a need for quantum kinetic treatment in the numerical modeling of neutrino dynamics, which is, however, a formidable computational challenge. In this paper, we present an approximate method to predict asymptotic states of FFC without solving a quantum kinetic equation under a three-flavor framework, in which mu and tau neutrino distributions are not necessarily identical to each other. The approximate method is developed based on a Bhatnagar-Gross-Krook (BGK) relaxation time prescription, capable of capturing essential features of mixing competitions among three different flavor-coherent states. Our proposed scheme is computationally inexpensive and easy to implement in any classical neutrino transport scheme.

    ↳ astro-ph.HEhep-phPRD(2025)·23 citations
47. 47*

    Gravitational Wave Signatures of Primordial Black Hole Reheating in Upcoming Interferometry Missions

    Debarun Paul🇮🇳 · Md Riajul Haque🇮🇳 · Supratik Pal🇮🇳

    We investigate the prospects of detecting a stochastic gravitational wave (GW) background from the primordial black hole (PBH) reheating epoch. If PBHs form during a non-standard cosmological phase prior to the radiation-dominated era, they can dominate the energy density of the Universe before evaporating via Hawking radiation. Such PBHs can generate induced GWs that may fall within the detectable range of future interferometry missions: (i) through isocurvature perturbations arising from the inhomogeneous spatial distribution of PBHs, and (ii) through the amplification of adiabatic perturbations triggered by the abrupt transition from PBH domination to radiation domination. We assess the detection prospects of such GW spectra using the signal-to-noise ratio, Fisher forecast analysis, and Markov chain Monte Carlo analysis with mock data from LISA and ET. Our findings reveal that ET exhibits superior sensitivity to both isocurvature- and adiabatic-induced GWs, covering a wide PBH mass range of $M_{\mathrm{in}}\in (0.5-4\times 10^7)$ g. However, we find that the relative uncertainties associated with the parameter of the isocurvature source are quite high. LISA, by contrast, is mostly sensitive to the adiabatic source, with $M_{\mathrm{in}}\in (2\times 10^4-5\times 10^8)$ g. The combined effect of adiabatic and isocurvature sources on ET and LISA provides a multi-stage window into the post-inflationary Universe by constraining PBH mass, energy fraction, and the background equation of state.

    ↳ astro-ph.COhep-phJCAP(2025)·8 citations
48. 48*

    Future Opportunities with Lepton-Hadron Collisions

    Allen Caldwell🇩🇪 · Silvia Dalla Torre🇮🇹 · Rolf Ent🇺🇸 · Aharon Levy🇮🇱 · Paul Newman🇬🇧 · Fred Olness🇺🇸 · Juan Rojo🇳🇱

    Deep Inelastic lepton-hadron Scattering (DIS) is a cornerstone of particle physics discovery and the precision measurement of the structure of matter. This document surveys the international DIS landscape, exploring current and future opportunities to continue this rich heritage, leading to new understandings and enabling discoveries. Of immediate relevance to the future of the field in Europe, the Large Hadron electron Collider (LHeC) offers an impactful bridge between the end of the HL-LHC and the beginning of the next CERN flagship project, both in terms of technology development and new scientific exploration from Higgs physics to the structure of the proton. More generally, the facilities described here cover energies from a few GeV to multiple TeV and address a wide range of topics, with unique sensitivity to Quantum Chromodynamics and hadron structure at their core. Additionally, they enhance the science programmes at hadron-hadron colliders. The fixed-target CEBAF programme at JLab probes nucleon and light ion structure at large x in novel ways, while high energy neutrino DIS is enabled at the FASER and SND@LHC experiments by the intense LHC beams. The Electron Ion Collider (EIC) is on course for deployment at Brookhaven in the early 2030s. Its science includes a 3-dimensional mapping of hadrons, leading to a thorough understanding of the mechanisms behind proton mass and spin. Adding the LHeC provides a Europe-based lepton-hadron frontier, including a complementary Higgs, top and electroweak programme to the HL-LHC, together with precise determinations of proton and nuclear structure in a kinematic range that improves HL-LHC sensitivities. In the longer term, plasma wakefield acceleration and the FCC offer possible major steps forward in centre-of-mass energy, extending into a low parton momentum-fraction domain where new strong interaction discoveries are guaranteed.

    ↳ hep-exhep-phnucl-ex1 citation
49. 49*

    New Tests on Lorentz Invariance Violation Using Energy-Resolved Polarimetry of Gamma-Ray Bursts

    Jun-Jie Wei🇨🇳

    One of the manifestations of Lorentz invariance violation (LIV) is vacuum birefringence, which leads to an energy-dependent rotation of the polarization plane of linearly polarized photons arising from an astrophysical source. Here we use the energy-resolved polarization measurements in the prompt $\gamma$-ray emission of five bright gamma-ray bursts (GRBs) to constrain this vacuum birefringent effect. Our results show that at the 95\% confidence level, the birefringent parameter $\eta$ characterizing the broken degree of Lorentz invariance can be constrained to be $|\eta |<\mathcal{O}(10^{-15}-10^{-16})$, which represent an improvement of at least eight orders of magnitude over existing limits from multi-band optical polarization observations. Moreover, our constraints are competitive with previous best bounds from the single $\gamma$-ray polarimetry of other GRBs. We emphasize that, thanks to the adoption of the energy-resolved polarimetric data set, our results on $\eta$ are statistically more robust. Future polarization measurements of GRBs at higher energies and larger distances would further improve LIV limits through the birefringent effect.

    ↳ astro-ph.HEgr-qchep-phApJ(2025)·0 citations
50. 50*

    Second order fluctuations of conserved charges in external magnetic fields

    Heng-Tong Ding🇨🇳 · Jin-Biao Gu🇨🇳 · Arpith Kumar🇨🇳 · Sheng-Tai Li🇨🇳

    We present a first-principles lattice QCD investigation of second-order fluctuations of and correlations among conserved charges -- baryon number (B), electric charge (Q), and strangeness (S) -- in the presence of external magnetic fields. Our study employs lattice simulations of (2+1)-flavor QCD with physical pion masses using highly improved staggered fermions (HISQ) on $48^3\times 12$ and $32^3\times 8$ lattices, covering a wide range of magnetic field strengths up to $eB\simeq 0.8$ GeV${}^2$. We identify clear signals of magnetic field-induced modifications to these fluctuations and correlations, with the baryon-electric charge correlation, ${\chi }_{11}^{\mathrm{BQ}}$, exhibiting particularly strong sensitivity to the magnetic field. To bridge theoretical predictions with experimental observables, we implement systematic kinematic cuts that emulate detector acceptances of the STAR and ALICE experiments within the hadron resonance gas (HRG) model and construct proxy observables for fluctuations measurable in heavy-ion collision experiments. Our findings highlight ${\chi }_{11}^{\mathrm{BQ}}$ as a promising ``magnetometer" for probing the presence of magnetic fields in QCD matter. Furthermore, we explore experimentally relevant ratios involving ${\chi }_{11}^{\mathrm{BQ}}$, demonstrating their potential in mitigating volume effects and enhancing sensitivity to magnetic fields in collision environments. Additionally, we assess the limitations of the HRG model at strong magnetic fields, revealing deviations that indicate nontrivial modifications to hadronic degrees of freedom. These results offer new insights into the interplay between thermal and magnetic effects in the QCD phase diagram and provide experimentally relevant guidance for the detection of magnetic fields in heavy-ion collisions.

    ↳ hep-lathep-phnucl-exnucl-thPRD(2025)·20 citations
51. 51*

    About testing Bell locality at colliders

    M. Fabbrichesi🇮🇹 · R. Floreanini🇮🇹 · L. Marzola🇪🇪

    High-energy colliders enable the testing of quantum mechanics at its most fundamental level, in the presence of strong and electroweak interactions, with systems that consist of qubits (fermions) and qutrits (massive spin-1 bosons). Quantum state tomography at colliders enables the witnessing of entanglement and Bell non-locality, two defining characteristics of quantum mechanics. We offer a comprehensive explanation of the underlying principles and the methods employed to achieve this remarkable feat.

    ↳ quant-phhep-exhep-phphysics.hist-phFound.Phys.(2025)·16 citations
52. 52*

    Probing Entanglement Dynamics in the SYK Model using Quantum Computers

    Talal Ahmed Chowdhury🇧🇩 · Kwangmin Yu🇺🇸 · Raza Sabbir Sufian🇺🇸

    Quantum computers are expected to be vital for exploring complex dynamics in many-body quantum systems. Thus, validating established results on current quantum computers is essential for evaluating their future utility. Hence, we investigate the entanglement entropy of the Sachdev-Ye-Kitaev (SYK) model, a paradigmatic model of quantum chaos, many-body physics, and holographic duality, in current IBM's superconducting quantum computers. We implement optimized swap-based many-body interference protocol and randomized measurement protocol tailored for IBM quantum computers' limited qubit connectivity. Additionally, we employ quantum multi-programming that parallelizes circuit execution to improve the results obtained by the randomized measurement protocol. Finally, by incorporating the quantum error mitigation techniques into our implementation of the entropy measurement protocols on IBM quantum hardware, we show that the current noisy quantum computer can yield results aligned with theoretical expectations, therefore affirming its capability to explore chaotic quantum dynamics in complex quantum systems.

    ↳ quant-phcond-mat.str-elhep-lathep-ph+1Results Phys.(2025)·8 citations
53. 53*

    Chiral and deconfinement thermal transitions at finite quark spin polarization in lattice QCD simulations

    V. V. Braguta🇷🇺 · M. N. Chernodub🇫🇷 · A. A. Roenko🇷🇺

    We study the effect of finite spin quark density on the chiral and deconfinement thermal crossovers using numerical simulations of lattice QCD with two dynamical light quarks. The finite spin density is introduced by the quark spin potential in the canonical formulation of the spin operator. We show that both chiral and deconfinement temperatures are decreasing functions of the spin potential. We determine the parabolic curvatures of crossover temperatures in a limit of physical quark masses.

    ↳ hep-lathep-phhep-thPRD(2025)·10 citations
54. 54*

    Relativistic ${}^3$He light-front wave function

    V.A. Karmanov🇷🇺 · Zhimin Zhu🇨🇳 · Ziqi Zhang🇨🇳 · Kaiyu Fu🇨🇳

    The relativistic light-front (LF) wave function of ${}^3$He is determined by the three-body LF equation for the Faddeev components in the momentum space. As an interaction, we take the one-meson exchange kernels, without the potential approximation. Within the explicitly covariant formulation of LF dynamics, we calculate the full relativistic ${}^3$He LF wave function, comprising 32 spin-isospin components. In the non-relativistic domain, five of these components dominate and closely resemble their non-relativistic counterparts. Relativistic effects manifest themselves in deviations in relativistic domain of these components from the non-relativistic ones and in appearance of new components.

    ↳ nucl-thhep-phJ.Subatomic Part.Cosmol.(2025)·1 citation
55. 55*

    Generalized relativistic second-order dissipative hydrodynamics: coupling different rank tensors

    Arus Harutyunyan🇦🇲 · Armen Sedrakian🇩🇪

    In this work, we extend the formalism of second-order relativistic dissipative hydrodynamics, developed previously using Zubarev's non-equilibrium statistical operator formalism. By employing a second-order expansion of the statistical operator in terms of hydrodynamic gradients, we demonstrate that new second-order terms emerge due to the coupling of two-point quantum correlators between tensors of differing ranks, evaluated at distinct space-time points. Such terms arise because the presence of the acceleration vector in the system allows Curie's theorem, which governs symmetry constraints, to be extended for constructing invariants from tensors of different ranks evaluated at distinct space-time points. The new terms are identified in the context of a complete set of second-order equations governing the shear-stress tensor, bulk-viscous pressure, and charge-diffusion currents for a generic quantum system characterized by the energy-momentum tensor and multiple conserved charges. Additionally, we identify the transport coefficients associated with these new terms and derive the Kubo formulas expressing the second-order transport coefficients through two- and three-point correlation functions.

    ↳ nucl-thastro-ph.HEhep-phAnnals Phys.(2025)·3 citations
56. 56*

    Interpreting Cosmic Birefringence and DESI Data with Evolving Axion in $\Lambda$CDM

    Shota Nakagawa🇨🇳 · Yuichiro Nakai🇨🇳 · Yu-Cheng Qiu🇨🇳 · Masaki Yamada🇯🇵

    Recent cosmological observations have revealed growing tensions with the standard $\Lambda$CDM model, including indications of isotropic cosmic birefringence and deviations from $w=-1$ in the dark energy equation of state, as suggested by DESI and supernova measurements. In this paper, we point out that such deviations can arise even from a subdominant energy density component. We then propose a unified framework based on a dynamical axion field that simultaneously accounts for both anomalies, providing a simple and natural extension of the standard $\Lambda$CDM model. In our scenario, the axion field with $2H_0\lesssim m\lesssim 6H_0$, where $H_0$ is the current Hubble constant, induces a nonzero rotation of the CMB polarization plane and modifies the present-day dark energy equation of state. This framework accommodates recent observational data with natural parameter choices, even for a string axion with a decay constant of order $10^{17}$GeV.

    ↳ astro-ph.COhep-phhep-thPLB(2025)·20 citations
57. 57*

    The Forward Physics Facility at the Large Hadron Collider

    Luis A. Anchordoqui🇺🇸 · Akitaka Ariga🇨🇭 · Tomoko Ariga🇯🇵 · Alan J. Barr🇬🇧 · Brian Batell🇺🇸 · Jianming Bian🇺🇸 · Jamie Boyd🇨🇭 · Matthew Citron🇺🇸 · Albert De Roeck🇨🇭 · Milind V. Diwan🇺🇸 · Jonathan L. Feng🇺🇸 · Christopher S. Hill🇺🇸 and 12 other authors

    The Forward Physics Facility (FPF) is a proposal developed to exploit the unique scientific potential made possible by the intense hadron beams produced in the far-forward direction at the high luminosity LHC (HL-LHC). Housed in a well-shielded cavern 627 m from the LHC interactions, the facility will enable a broad and deep scientific programme which will greatly extend the physics capability of the HL-LHC. Instrumented with a suite of four complementary detectors -- FLArE, FASER$\nu$2, FASER2 and FORMOSA -- the FPF has unique potential to shed light on neutrino physics, QCD, astroparticle physics, and to search for dark matter and other new particles. This contribution describes some of the key scientific drivers for the facility, the engineering and technical studies that have been made in preparation for it, the design of its four complementary experiments, and the status of the project's partnerships and planning.

    ↳ hep-exhep-ph17 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.