Fri·Nov 1, 2024Friday·November 1, 2024

1. 01*

   Dark Matter Candidates and Searches

   Nassim Bozorgnia🇨🇦 · Joseph Bramante🇨🇦 · James M. Cline🇨🇦 · David Curtin🇨🇦 · David McKeen🇨🇦 · David E. Morrissey🇨🇦 · Adam Ritz🇨🇦 · Simon Viel🇨🇦 · Aaron C. Vincent🇨🇦 · Yue Zhang🇨🇦

   Astrophysical observations suggest that most of the matter in the cosmos consists of a new form that has not been observed on Earth. The nature and origin of this mysterious dark matter are among the most pressing questions in fundamental science. In this review we summarize the current state of dark matter research from two perspectives. First, we provide an overview of the leading theoretical proposals for dark matter. And second, we describe how these proposals have driven a broad and diverse global search program for dark matter involving direct laboratory searches and astrophysical observations. This review is based on a Green Paper on dark matter prepared as part of the 2020 Astroparticle Community Planning initiative undertaken by the Canadian Subatomic Physics community but has been significantly updated to reflect recent advances.

   hep-phCan.J.Phys.(2025)·58 citations
2. 02*

   QGSJET-III: predictions for extensive air shower characteristics and the corresponding uncertainties

   Sergey Ostapchenko🇩🇪

   The physics content of the QGSJET-III Monte Carlo model of high energy hadronic interactions is briefly described. The predictions of the model for extensive air shower characteristics are presented in comparison to the corresponding results of other Monte Carlo generators of cosmic ray interactions. The results of a recent quantitative analysis of uncertainties for such predictions are discussed, notably, regarding possibilities to enhance the muon content of extensive air showers or to delay the air shower development.

   hep-phastro-ph.HE1 citation
3. 03*

   Likelihood and Correlation Analysis of Compton Form Factors for Deeply Virtual Exclusive Scattering on the Nucleon

   Douglas Q. Adams🇺🇸 · Joshua Bautista🇺🇸 · Marija Cuic🇺🇸 · Adil Khawaja🇺🇸 · Saraswati Pandey🇺🇸 · Zaki Panjsheeri🇺🇸 · Gia-Wei Chern🇺🇸 · Yaohang Li🇺🇸 · Simonetta Liuti🇺🇸 · Marie Boer🇺🇸 · Michael Engelhardt🇺🇸 · Gary R. Goldstein🇺🇸 · Huey-Wen Lin🇺🇸 · Matthew D. Sievert🇺🇸

   A likelihood analysis of the observables in deeply virtual exclusive photoproduction off a proton target, $ep\to e^{\prime }{p}^{\prime }{\gamma }^{\prime }$, is presented. Two processes contribute to the reaction: deeply virtual Compton scattering, where the photon is produced at the proton vertex, and the Bether-Heitler process, where the photon is radiated from the electron. We consider the unpolarized process for which the largest amount of data with all the kinematic dependences are available from corresponding datasets with unpolarized beams and unpolarized targets from Jefferson Lab. We provide and use a method which derives a joint likelihood of the Compton form factors, which parametrize the deeply virtual Compton scattering amplitude in QCD, for each observed combination of the kinematic variables defining the reaction. The unpolarized twist-two cross section likelihood fully constrains only three of the Compton form factors (CFFs). The impact of the twist-three corrections to the analysis is also explored. The derived likelihoods are explored using Markov chain Monte Carlo (MCMC) methods. Using our proposed method we derive CFF error bars and covariances. Additionally, we explore methods which may reduce the magnitude of error bars/contours in the future.

   hep-ph9 citations
4. 04*

   Chiral transition and meson melting within improved holographic soft wall models

   Alfonso Ballon-Bayona🇧🇷 · Sean Bartz🇺🇸 · Luis A. H. Mamani🇧🇷 · Diego M. Rodrigues🇧🇷

   We describe the chiral transition for the quark condensate and the melting of scalar and vector mesons in two-flavor holographic QCD. This is done by extending the improved holographic soft wall models proposed in [1] to finite temperature, by means of introducing an asymptotically AdS black brane. We find that the chiral transition is second order in the chiral limit and a crossover for physical quark masses, as expected in two-flavor QCD. We investigate the melting of vector and scalar mesons in the deconfined plasma through the calculation of hadronic spectral functions. Fixing the model parameters by the meson spectrum at zero temperature, we find that the mesons melt at temperatures between $90$ and $110$ MeV and the chiral transition occurs around $129$ MeV. We also provide a prediction for the hydrodynamic diffusion constant associated with a flavor current in the deconfined plasma.

   hep-phhep-lathep-thPRD(2025)·6 citations
5. 05*

   QCD phase transition with non-extensive NJL model in the strong magnetic field

   Jia Zhang🇨🇳 · Xin-Jian Wen🇨🇳

   In this work we make use of the Nambu-Jona-Lasinio model to investigate thermodynamic properties of magnetized three-flavor quark matter. The non-equilibrium Tsallis distribution is characterized by a dimensionless non-extensive parameter $q$. We find that the system always undergoes a crossover transition for all given $q$ values and the pseudo-critical temperature decreases with the increasing non-extensive parameter. We show that the variation of the pressure and its anisotropy in parallel and perpendicular directions. However, the diamagnetic nature appears within a certain temperature range at zero chemical potential. Moreover, strong magnetic fields can affect the property of a non-extensive system by changing the magnetization significantly. At high temperatures, the paramagnetic nature always occur no matter how strong the magnetic field is. Finally, we study the effects of non-extensive parameter $q$ on the trace anomaly and the speed of sound of the system.

   hep-phPRD(2024)·3 citations
6. 06*

   Direct Detection of Dark Baryons Naturally Suppressed by $\mathcal{H}$-parity

   Pouya Asadi🇺🇸 · Graham D. Kribs🇺🇸 · Chester J. Hamilton Mantel🇺🇸

   We identify symmetries in a broad class of vector-like confining dark sectors that forbid the leading electromagnetic moments that would ordinarily mediate dark baryon scattering with the Standard Model. The absence of these operators implies dark baryon dark matter has much smaller cross sections for elastic scattering off nuclei, leading to suppressed direct detection signals. In the confined description, we identify an ``$\mathcal{H}$-parity'' symmetry that exists in any dark sector with dark quarks transforming under a vector-like representation of a new confining SU($N_c$) gauge theory as well as a vector-like representation of the electroweak group SU(2)${}_L$. The parity is independent of $N_c$ and $N_f$, though it is essential that the dark quarks are neutral under hypercharge. This parity forbids dark hadron electric and magnetic dipole moments, charge radius, and anapole moment, while permitting dimension-7 operators that include polarizability, electroweak loop-induced interactions, as well as lower dimensional electromagnetic $\text{transition}$ moments between different neutral dark baryon states. We work out an explicit example, $N_c=N_f=3$, that is the most minimal theory with fermionic dark baryons. In this specific model, we use the non-relativistic quark model to show the magnetic dipole moment and charge radius vanish while the transition moments are non-zero, consistent with $\mathcal{H}$-parity. We discuss the implications of a suppressed direct detection signal, emphasizing that this broad class of models provide a well-motivated target for future colliders.

   hep-phPRD(2025)·8 citations
7. 07*

   Polarization-dependent observables in $H\to {\ell }^{+}{\ell }^{-}\gamma$ in the SM

   Usman Hasan🇵🇰 · A. Uzair🇵🇰 · M. Junaid🇵🇰 · Bilal Tariq🇵🇰 · Ishtiaq Ahmed🇵🇰 · Shahin Iqbal🇵🇰

   The rare three body decay of a Higgs boson to a lepton-anti lepton pair and a photon has begun to attract attention, after the first evidence for the $H\to Z\gamma$ at CMS and ATLAS, which is a sub process of $H\to {\ell }^{+}{\ell }^{-}\gamma$ . To investigate some important features of this process, we suggest that the polarized forward-backward and the photon polarization asymmetries could be useful to probe its important properties, such as the behavior of Yukawa coupling, resonance, and non-resonance contributions. Our analysis introduces a comprehensive framework to evaluate the aforementioned polarization-dependent observables. By analyzing the polarization effects of the final-state photon and lepton separately on forward-backward asymmetries, we demonstrate that loop-induced contributions play a significant role to investigate these asymmetries. Unlike the unpolarized case, where the interference effects of resonance and non-resonance effects are minimal, we show that polarization dependent observables offer a powerful tool to analyze these features of this decay mode. Furthermore, these observables can provide a handy tool for probing possible signatures of physics beyond the SM.

   hep-phPTEP(2025)·1 citation
8. 08*

   Phenomenology of a singlet-doublet-triplet scotogenic framework

   Ugo de Noyers🇫🇷 · Maud Sarazin🇨🇴 · Björn Herrmann🇫🇷

   We present an extensive phenomenological study of a scotogenic framework including a scalar singlet, a scalar doublet, a fermionic doublet, and two generations of a fermionic triplet, allowing to provide three non-zero neutrino masses and three viable dark matter candidates. Using a Markov Chain Monte Carlo numerical technique, we probe the parameter space of the model in view of numerous constraints stemming from dark matter, the neutrino sector, and lepton-flavour violating transitions. The dark matter mass distribution of phenomenologically viable scenarios exhibits three very predictive peaks at 550 GeV, 1080 GeV, and 2300 GeV. In all viable parameter regions, the observed relic density is achieved through dominant co-annihilations. Future experiments will be able to probe a large number of the currently viable parameter space, while certain parameter configurations promise interesting collider signatures. For related studies, five typical parameter configurations are given in SLHA format.

   hep-phEPJC(2025)·5 citations
9. 09*

   Hadronization in small and large systems

   Andrea Beraudo🇮🇹

   Recent results on particle production in hadronic collisions at the LHC, from proton-proton (pp) to nucleus-nucleus (AA), challenge the traditional paradigm of hadronization as a universal late-time process which can be factorized from the partonic description of the rest of the event. If the violation of this description in nuclear collisions has been accepted for long -- with several hadronic observables finding a natural interpretation assuming some form of recombination of partons from a deconfined medium -- this same occurrence came as a surprise in proton-proton collisions. Actually, strong indications that hadronization cannot be simply described by universal fragmentation fractions/functions were already found in fixed-target experiments, but limited to specific kinematic regions close to the beam rapidity, so that a complete change of paradigm did not look necessary. Here we show that a wide set of observables finds a natural interpretation assuming that in all high-energy hadronic collisions, from pp to AA, a deconfined medium is formed, acting as a reservoir in which a parton can undergo local color neutralization (LCN) through recombination with an opposite color charge. Hadronization, belonging to the non-perturbative domain of QCD, will always, inevitably, require some amount of educated modelling. However, some commong features to the various proposed model in the literature can be identified, which look necessary in order to describe the most recent data. Here we decide to focus on heavy-flavor (HF) production, since in this case the origin of at least one of the consituent quarks of the final hadron is well known and attributed to an initial hard partonic process.

   hep-phnucl-thPoS(2025)·2 citations
10. 10*

    Disentangling data contributions to the precision measurement of the largest leptonic mixing angle

    P.T.Quyen🇻🇳 · Son Cao🇻🇳 · N.T.Hong Van🇻🇳

    This study examines the precise measurement of the largest leptonic mixing angle ${\theta }_{23}$ through the analysis of neutrino oscillation data samples. Our findings indicate that, contrary to common understanding, the ${\nu }_{\mu }({\bar{\nu }}_{\mu })\to {\nu }_e({\bar{\nu }}_e)$ appearance samples, rather than the ${\nu }_{\mu }({\bar{\nu }}_{\mu })\to {\nu }_{\mu }({\bar{\nu }}_{\mu })$ disappearance samples, are sensitive to test the hypothesis of maximal mixing ${\theta }_{23}=\pi /4$, particularly if ${\theta }_{23}$ resides in the higher octant and ${\sin }^2{\theta }_{23}<0.54$. The former serves as the primary source for determining the octant of the ${\theta }_{23}$ mixing angle; however, the latter remains relevant if ${\theta }_{23}$ is indeed in the lower octant with ${\sin }^2{\theta }_{23}<0.42$. In a joint T2HK and DUNE analysis, utilizing only appearance sub-samples can exclude the maximal-mixing and determine the actual octant for about 60\% of the currently allowed range of the ${\theta }_{23}$ angle. We argue that, despite the presence of parameter degeneracy, the precise measurement of ${\theta }_{23}$ exhibits minimal dependence on other unknown factors, including the CP-violation phase and neutrino mass ordering.

    hep-phPTEP(2025)·1 citation
11. 11*

    Evidence of the existence of the six-quark component of the deuteron in the energy spectra of photons emitted in proton-deuteron collisions

    A.S.Khrykin

    We present evidence of the existence of the six-quark component of the deuteron ($d_{6q}$) found in the experimental photon energy spectra of the proton deuteron bremsstrahlung measured at the proton incident energy of 200 MeV by the Grenoble group and of 195 MeV by the Michigan state group. A comparison of these spectra with the theoretically predicted ones revealed that the experimental spectra significantly exceed the theoretical ones. We show that the excess of photons in the experimental spectra was caused by contributions of new mechanisms for the photon production in $pd$ collisions, which are due to the existence of $d_{6q}$. The mechanisms comprise the process $p+d_{6q}\to p^{\prime }+d_{6q}^{\star }$, where $p^{\prime }$ is the scattered proton and $d_{6q}^{\star }$ is the $d_{6q}$ excited state, which has the total energy below the threshold for its decay by pion emission and the quantum numbers forbidden for the $NN$ system, that experiences then either the radiative decay $d_{6q}^{\star }\to p+n+\gamma$ or $d_{6q}^{\star }\to d+\gamma$. By assuming that $d_{6q}^{\star }$ is the $NN$-decoupled dibaryon $d_1^{\star }(1956)$, we calculated the expected contribution of these mechanisms to the most precisely measured energy spectrum of photons emitted at $90^0$ for an incident proton energy of 195 MeV. After a simple subtraction of this contribution from the experimental spectrum, we found that the experimetally and theoretically predicted spectra are in good agreement.

    hep-ph0 citations
12. 12*

    Electric, Magnetic and Quadrupole Form Factors and Charge Radii of Vector Mesons: From Light to Heavy Sector in a Contact Interaction

    R. J. Hernández-Pinto🇲🇽 · L. X. Gutiérrez-Guerrero🇲🇽 · M. A. Bedolla🇲🇽 · A. Bashir🇲🇽

    We present a detailed survey of electric, magnetic and quadrupole form factors of light and heavy spin-1 vector mesons. It complements our analogous analysis of the electromagnetic form factors of pseudoscalar and scalar mesons reported earlier. Our formalism is based upon the Schwinger-Dyson equations treatment of a vector $\times$ vector contact interaction and the Bethe-Salpeter equation description of relativistic two-body bound states. We compute the form factors, associated moments and charge radii, comparing these quantities to earlier theoretical studies and experimental results if and when possible. We also investigate the quark-mass dependence of the charge radii and find the anticipated hierarchy such that it decreases with increasing dressed quark masses. In addition, our analysis shows that the magnetic moment is independent of the mass of the light and heavy mesons. Our results agree with most measurements reported earlier, finding a negative quadrupole moment, implying the charge distribution is oblate.

    hep-phnucl-thPRD(2024)·24 citations
13. 13*

    Azimuthal asymmetries in lepton and heavy-quark pair production in UPCs

    Daniël Boer🇳🇱 · Luca Maxia🇳🇱 · Cristian Pisano🇮🇹

    Azimuthal modulations in lepton and heavy-quark pair production in ultraperipheral collisions (UPCs) of highly charged ions are investigated. The modulations in the azimuthal angles of the sum and difference of the transverse momenta of the pair of particles in the final state, as well as of the transverse impact parameter, arise from the collisions of unpolarized and polarized photons. A full description of the cross section in terms of Generalized Transverse Momentum Dependent parton distributions (GTMDs) for photons is given including a careful consideration of the Fourier transform to impact parameter space. In particular, this leads to a feed-in mechanism among harmonics of different orders, which in principle generates harmonics of all (even) orders. Wherever comparable, our analytical results for the azimuthal modulations agree with those presented in other papers on this topic. Compared to these other works, we separate effects that arise from the anisotropies of the GTMDs from those that do not and retain terms proportional to the mass of the produced particles, as they are relevant for muon, charm and bottom quark production. We show that the normalized differential cross section changes considerably with the produced particle mass, which should be discernible in UPCs at RHIC and LHC. For the numerical results we adopt several models for the photon GTMD correlator, and find that all of them are in fairly good agreement with each other and with UPC data from STAR. We also present results for various azimuthal modulations for RHIC kinematics, where we compare $e^{+}{e}^{-}$ production with the production of heavier particles, and for LHC kinematics, focusing on ${\mu }^{+}{\mu }^{-}$ production. These results exhibit interesting mass-dependent features in the asymmetries that may help study the anisotropies arising from the underlying photon GTMD description.

    hep-phhep-exnucl-exJHEP(2025)·1 citation
14. 14*

    Large neutrino mass in cosmology and keV sterile neutrino dark matter from a dark sector

    Cristina Benso🇩🇪 · Thomas Schwetz🇩🇪 · Drona Vatsyayan🇪🇸

    We consider an extended seesaw model which generates active neutrino masses via the usual type-I seesaw and leads to a large number of massless fermions as well as a sterile neutrino dark matter (DM) candidate in the $\mathcal{O}(10-100)\mathrm{keV}$ mass range. The dark sector comes into thermal equilibrium with Standard Model neutrinos after neutrino decoupling and before recombination via a U(1) gauge interaction in the dark sector. This suppresses the abundance of active neutrinos and therefore reconciles sizeable neutrino masses with cosmology. The DM abundance is determined by freeze-out in the dark sector, which allows avoiding bounds from X-ray searches. Our scenario predicts a slight increase in the effective number of neutrino species $N_{\mathrm{eff}}$ at recombination, potentially detectable by future CMB missions.

    hep-phastro-ph.COJCAP(2025)·23 citations
15. 15*

    Non-holomorphic modular $A_5$ symmetry for lepton masses and mixing

    Cai-Chang Li🇨🇳 · Jun-Nan Lu🇨🇳 · Gui-Jun Ding🇨🇳

    We perform a comprehensive bottom-up study of all the simplest lepton models based on non-holomorphic $A_5$ modular flavor symmetry, in which neutrinos are assumed to be Majorana particles and their masses are generated by the Weinberg operator or the type I seesaw mechanism. In the case that the generalized CP (gCP) symmetry is not considered, we find that 21 Weinberg operator models and 174 seesaw models can accommodate the experimental data in lepton sector, and all of them depend on six dimensionless free parameters and two overall scales. If gCP symmetry compatible with $A_5$ modular symmetry is imposed, one more free parameter would be reduced. Then only 4 of the 21 Weinberg operator models and 100 of the 174 seesaw models agree with the experimental data on lepton masses and mixing parameters. Furthermore, we perform a detailed numerical analysis for two example models for illustration.

    hep-phJHEP(2024)·30 citations
16. 16*

    Dirac Leptogenesis in Left-Right Symmetric Models

    K.S. Babu🇺🇸 · Ajay Kaladharan🇺🇸

    Left-right symmetric models which employ a generalized seesaw mechanism to generate quark and charged lepton masses are known to solve the strong CP problem via parity symmetry, without the need for the axion. These models lead to naturally light Dirac neutrinos with their masses arising through radiatve corrections. In this work, we show how baryogenesis via Dirac leptogenesis can be implemented in this framework. A pair of left-right symmetric scalar doublets ${\varphi }_{L,R}$ carrying $(B-L)$ charge of $3$ is introduced for this purpose, which preserves the parity solution to the strong CP problem. Small neutrino masses are generated through one-loop diagrams mediated by these scalars. The decay of vector-like leptons ($E_i$) involved in the seesaw mechanism to generate charged lepton masses, $E_i\to {\overline{\nu }}_{jR}{\varphi }_R^{-}$, creates a right-handed neutrino (${\nu }_R$) asymmetry, while preserving total lepton number. The compensating lepton asymmetry is converted to baryon asymmetry via electroweak sphalerons. We show that for a large range of model parameters successful baryogenesis can be realized, with the $W_R^{\pm }$ gauge boson mass of order $10^{11}$ GeV.

    hep-phastro-ph.COPRD(2025)·12 citations
17. 17*

    A generalized picture of colour decoherence in dense QCD media

    Samuel Abreu🇨🇭 · Xoán Mayo López🇪🇸 · Guilherme Milhano🇵🇹 · Alba Soto-Ontoso🇪🇸

    We revisit the calculation of the soft gluon emission probability off a colour-singlet $q\bar{q}$ system that evolves in a quark-gluon plasma. The $q\bar{q}$ antenna is created in the presence of a medium and then emits a soft gluon outside. The gluon emission probability is modified with respect to the vacuum baseline due to interactions with the medium during the formation of the antenna and its propagation. Previous studies disregarded the former effect and found that the medium modification to the interference pattern of the antenna was controlled by the so-called critical angle ${\theta }_c$, that exclusively depends on medium properties. We find that accounting for medium interactions during the antenna formation enhances the total rate of emissions off the $q\bar{q}$ antenna. Interestingly, it also promotes the notion of a critical angle to a dynamic quantity, denoted ${\tilde{\theta }}_c$, that depends on both the medium and the antenna properties and is thus different for every splitting. As a consequence, depending on the region of parameter space, colour decoherence can either be delayed or accelerated with respect to previous estimates.

    hep-phhep-exnucl-thJHEP(2025)·20 citations
18. 18*

    Progress in top-quark pair production cross section calculations and impact on parton distribution functions of the proton

    Alim Ablat🇨🇳 · Sayipjamal Dulat🇨🇳 · Marco Guzzi🇺🇸 · Tie-Jiun Hou🇨🇳 · Nikolaos Kidonakis🇺🇸 · Ibrahim Sitiwaldi🇨🇳 · Alberto Tonero🇺🇸 · Keping Xie🇺🇸 · C.-P. Yuan🇺🇸

    We discuss the impact of eligible top-quark pair production differential cross-section measurements at the LHC with a collision energy of 13 TeV on the parton distribution functions (PDFs) of the proton as well as the impact of approximate next-to-next-to-next-to-leading order (aN${}^3$LO) QCD corrections combined with next-to-leading order (NLO) electroweak (EW) corrections on $t\bar{t}$ observables. We illustrate the effects on the gluon PDF at large $x$ from an optimal baseline selection of data in NNLO global fits, and show comparisons between the theory prediction for $t\bar{t}$ total and differential cross sections at aN${}^3$LO QCD combined with NLO EW and recent measurements from the ATLAS and CMS collaborations at the LHC.

    hep-phPoS(2025)·3 citations
19. 19*

    Light states in real multi-Higgs models with spontaneous CP violation

    Carlos Miró🇪🇸 · Miguel Nebot🇪🇸 · Daniel Queiroz (Valencia U., IFIC)🇪🇸

    In models with extended scalar sectors consisting of multiple Higgs doublets that trigger spontaneous electroweak symmetry breaking, it might be expected that the abundance of dimensionful quadratic couplings in the scalar potential could allow for a regime where, apart from the would-be Goldstone bosons and a neutral Higgs-like state, all new scalars have masses much larger than the electroweak scale. In the case of models where CP invariance holds at the lagrangian level but is broken by the vacuum, we show that such a reasonable expectation does not hold. When perturbativity requirements are placed on the dimensionless quartic couplings, the spectrum of the new scalars includes one charged and two additional neutral states whose masses cannot be much larger than the electroweak scale.

    hep-phPRD(2025)·8 citations
20. 20*

    Accurate and robust methods for direct background estimation in resonant anomaly detection

    Ranit Das🇺🇸 · Thorben Finke🇩🇪 · Marie Hein🇩🇪 · Gregor Kasieczka🇩🇪 · Michael Krämer🇩🇪 · Alexander Mück🇩🇪 · David Shih🇺🇸

    Resonant anomaly detection methods have great potential for enhancing the sensitivity of traditional bump hunt searches. A key component of these methods is a high quality background template used to produce an anomaly score. Using the LHC Olympics R&D dataset, we demonstrate that this background template can also be repurposed to directly estimate the background expectation in a simple cut and count setup. In contrast to a traditional bump hunt, no fit to the invariant mass distribution is needed, thereby avoiding the potential problem of background sculpting. Furthermore, direct background estimation allows working with large background rejection rates, where resonant anomaly detection methods typically show their greatest improvement in significance.

    hep-phhep-exphysics.data-anPRD(2025)·3 citations
21. 21*

    Constraints on dark matter with future MeV gamma-ray telescopes

    Kayla E. O'Donnell🇺🇸 · Tracy R. Slatyer🇺🇸

    A number of new balloon or space-based $\gamma$-ray observatories have been proposed to close a "MeV gap" in sensitivity to $\gamma$ rays in the MeV-GeV energy band. One aspect of the science case for these instruments is their ability to constrain or discover decaying or annihilating dark matter. In this work, we forecast the sensitivity of these instruments for dark matter annihilation or decay for a range of possible Standard Model final states and compare to existing bounds.

    hep-phastro-ph.HEPRD(2025)·27 citations
22. 22*

    Improving the Global SMEFT Picture with Bounds on Neutrino NSI

    Pilar Coloma🇪🇸 · Enrique Fernández-Martínez🇪🇸 · Jacobo López-Pavón🇪🇸 · Xabier Marcano🇪🇸 · Daniel Naredo-Tuero🇪🇸 · Salvador Urrea🇫🇷

    We analyze how neutrino oscillation and coherent elastic neutrino-nucleus scattering data impact the global SMEFT fit. We first review the mapping between the SMEFT parameters and the so-called NSI framework, commonly considered in the neutrino literature. We also present a detailed discussion of how the measurements for the normalization of neutrino fluxes and cross sections, that will also be affected by the new physics, indirectly impact the measured oscillation probabilities. We then analyze two well-motivated simplified scenarios. Firstly, we study a lepton flavour conserving case, usually assumed in global SMEFT analyses, showing the complementarity of neutrino oscillation and CE$\nu$NS experiments with other low-energy observables. We find that the inclusion of neutrino data allows to constrain previously unbounded SMEFT operators involving the tau flavour and confirm the improvement of the constraint on a combination of Wilson coefficients previously identified. Moreover, we find that neutrino oscillation constraints on NSI are improved when embedded in the global SMEFT framework. Secondly, we study a lepton flavour violating scenario and find that neutrino data also improves over previously derived global constraints thanks to its sensitivity to new combinations of Wilson coefficients.

    hep-phhep-exJHEP(2025)·15 citations
23. 23*

    Machine Learning Electroweakino Production

    Rafał Masełek🇵🇱 · Mihoko M. Nojiri🇯🇵 · Kazuki Sakurai🇵🇱

    The system of light electroweakinos and heavy squarks gives rise to one of the most challenging signatures to detect at the LHC. It consists of missing transverse energy recoiled against a few hadronic jets originating either from QCD radiation or squark decays. The analysis generally suffers from the large irreducible Z + jets $(Z\to \nu \bar{\nu })$ background. In this study, we explore Machine Learning (ML) methods for efficient signal/background discrimination. Our best attempt uses both reconstructed (jets, missing transverse energy, etc.) and low-level (particle-flow) objects. We find that the discrimination performance improves as the pT threshold for soft particles is lowered from 10 GeV to 1 GeV, at the expense of larger systematic uncertainty. In many cases, the ML method provides a factor two enhancement in $S/\sqrt{(S+B)}$ from a simple kinematical selection. The sensitivity on the squark-elecroweakino mass plane is derived with this method, assuming the Run-3 and HL-LHC luminosities. Moreover, we investigate the relations between input features and the network's classification performance to reveal the physical information used in the background/signal discrimination process.

    hep-phhep-exEPJC(2025)·2 citations
24. 24*

    Maximal value for trilinear Higgs coupling in a 3-3-1 EFT

    Adriano Cherchiglia🇧🇷 · Leonardo J. Ferreira Leite🇧🇷

    Recent efforts, both theoretical and experimental, have increasingly focused on the scalar potential of the Standard Model, with a highlight on the trilinear Higgs coupling. This parameter has long been recognized for its potential to test Beyond-Standard-Model (BSM) theories and its significance in understanding early cosmological dynamics. In order to broadly map BSM scenarios, a powerful tool is to devise its effective field theory (EFT) version for low-energies. In this work, we obtain a consistent EFT for a class of models based on the gauge group $SU(3{)}_c\times SU(3{)}_L\times U(1{)}_Y$. After properly matching the UV-complete theory at one-loop, we show that the EFT is a Two-Higgs-Doublet Model (2HDM), where some of the quartic couplings are naturally small. By imposing bounds from electroweak precision observables, collider, flavor, as well as theoretical considerations, we obtain that the maximum value of the trilinear Higgs coupling is more than four times larger than the SM prediction, potentially testable at the LHC Hi-Lumi upgrade and other future colliders. Moreover, we find that such large values are only attainable if one considers an out-of-alignment scenario, even if the deviation is very small.

    hep-phJHEP(2025)·7 citations
25. 25*

    Why detect forward muons at a muon collider

    Maximilian Ruhdorfer🇺🇸 · Ennio Salvioni🇬🇧 · Andrea Wulzer🇪🇸

    We survey the opportunities offered by the detection of the forward muons that accompany the creation of neutral effective vector bosons at a muon collider, in different kinematic regimes. Vectors with relatively low energy produce the Higgs boson and the extended muon angular coverage enables studies of the Higgs properties, such as the measurement of the inclusive production cross section and of the branching ratio to invisible final states. New heavy particles could be produced by vectors of higher energy, through Higgs portal interactions. If the new particles are invisible, the detection of the forward muons is essential in order to search for this scenario. The angular correlations of the forward muons are sensitive to the quantum interference between the vector boson helicity amplitudes and can be exploited for the characterisation of vector boson scattering and fusion processes. This is illustrated by analysing the CP properties of the Higgs coupling to the Z boson. Our findings provide a physics case and a set of benchmarks for the design of a dedicated forward muon detector.

    hep-phhep-exPRD(2025)·28 citations
26. 26*

    A functional treatment of small instanton-induced axion potentials

    Pablo Sesma🇫🇷

    We present a functional method to perform complete one-instanton calculations of the axion potential. This is done for an $SU(N)$ gauge theory with a matter content in any representation of the gauge group. This type of computation requires the expression of the fermion zero modes of the theory. We construct them for all representations of $SU(2)$, which serve as building blocks for obtaining the fermion zero modes for arbitrary representations of $SU(N)$. The method is applied to the Minimal Supersymmetric $SU(5)$ model and its low-energy counterpart, the Minimal Supersymmetric Standard Model extended with two color triplets.

    hep-phhep-thJHEP(2025)·11 citations
27. 27*

    Systematic Interpretability and the Likelihood for Boosted Top Quark Identification

    Andrew J. Larkoski🇺🇸

    Identification of boosted, hadronically-decaying top quarks is a problem of central importance for physics goals of the Large Hadron Collider. We present a theoretical analysis of top quark tagging, establishing zeroth-order, minimal assumptions that should be satisfied by any purported top-tagged jet, like existence of three hard subjets, a bottom-tagged subjet, total mass consistent with the top quark, and a pairwise subjet mass consistent with the W boson. From these minimal assumptions, we construct the optimal discrimination observable, the likelihood ratio, for the binary discrimination problem of top quark-initiated versus bottom quark-initiated jets through next-to-leading order in the strong coupling. We compare and compute corresponding signal and background efficiencies both analytically and from simulated data, validating an understanding of the relevant physics identified and exploited by the likelihood. In the process, we construct a method for systematic interpretability of the likelihood ratio for this problem, and explicitly establish a hard floor on possible discrimination power. These results can correspondingly be applied to understanding and interpreting machine learning studies of this problem.

    hep-phhep-ex5 citations
28. 28*

    Exploring vector dark matter via effective interactions

    Hrishabh Bharadwaj🇮🇳

    We explore the properties of self-conjugate dark matter (DM) particles that predominantly interact with Standard Model electroweak gauge bosons, using an effective field theory approach. The study emphasizes effective contact interactions, invariant under the Standard Model gauge group, between vector DM and SM-neutral electroweak gauge bosons. Focusing on interaction terms up to dimension-8, we establish constraints on the model parameters based on the observed DM relic density and indirect detection signals. We also examine the prospects for dark matter-nucleon scattering in direct detection experiments. In addition, we analyze the sensitivity of low-energy LEP data to the pair production of light DM particles (with masses up to 80 GeV). Finally, we assess the potential of the proposed International Linear Collider (ILC) to probe these effective operators through the detection of DM particles produced in association with mono-photons.

    hep-phCPC(2025)·0 citations
29. 29*

    Cheshire $\theta$ terms, Aharonov-Bohm effects, and axions

    Shi Chen🇺🇸 · Aleksey Cherman🇺🇸 · Gongjun Choi🇺🇸 · Maria Neuzil🇺🇸

    We discuss unusual $\theta$ terms that can appear in field theories that allow global vortices. These `Cheshire $\theta$ terms' induce Aharonov-Bohm effects for some particles that move around vortices. For example, a Cheshire $\theta$ term can appear in QCD coupled to an axion and induces Aharonov-Bohm effects for baryons and leptons moving around axion strings.

    ↳ hep-thhep-phPRD(2025)·10 citations
30. 30*

    Gravitational Polarizability of Schwarzschild Black Holes

    Gabriel Vidal🇧🇷 · Gabriel M. Dantas🇧🇷 · Riccardo Sturani🇧🇷 · Gabriel Menezes🇧🇷

    The linear response of a Schwarzschild black hole to an external quadrupolar perturbation is studied in analogy to a mechanical electrodynamical system, with the goal to describe the gravitational polarizability. Its causality properties imply dispersion relations that relate fluctuation and dissipative properties. We review and combine results obtained via the Regge-Wheeler equation on one side and a perturbative, worldline effective field theory description on the other, obtaining a consistent description of the dispersion relations for the gravitational polarizability of a Schwarzschild black hole. We find that the classical part of the 2-point correlation function of the black hole multipole depends on the boundary conditions of the space-time the black hole is immersed in, which is relevant for the dispersion relations considered.

    ↳ gr-qchep-phhep-th3 citations
31. 31*

    Growth of Gravitational Wave Spectrum from Sound Waves in a Universe with Generic Expansion Rate

    Yang Xiao🇨🇳 · Huai-Ke Guo🇨🇳 · Jiahang Hu🇨🇳 · Jin Min Yang🇨🇳 · Yang Zhang🇨🇳

    We derive a compact analytical expression for the growth factor ${\rm Y}$, which characterizes how the gravitational wave spectrum sourced by sound waves evolves in a universe with a generic expansion history. Assuming the dominant energy density scales as $\rho \propto a^{-3(1+w)}$, we obtain ${\rm Y}=\frac{2[1-y^{3(w-1)/2}]}{3(1-w)}$, where $y=a(t)/a(t_s)$ is the ratio of the scale factor at a later time $t$ to that at $t_s$ when gravitational wave production from sound waves starts. This general result reduces to known forms in radiation-and matter-dominated eras, thereby extending previous formulas to a broader class of cosmological backgrounds. The derivation assumes only that the source is stationary, making ${\rm Y}$ a universal factor that captures gravitational wave growth in various scenarios-not limited to phase transitions.

    ↳ gr-qcastro-ph.COhep-phPRD(2025)·7 citations
32. 32*

    Utility of a hybrid approach to the hadronic vacuum polarisation contribution to the muon anomalous magnetic moment

    C. T. H. Davies🇬🇧 · A. S. Kronfeld🇺🇸 · G. P. Lepage🇺🇸 · C. McNeile🇬🇧 · R. S. Van de Water🇺🇸

    An accurate calculation of the leading-order hadronic vacuum polarisation (LOHVP) contribution to the anomalous magnetic moment of the muon ($a_{\mu }$) is key to determining whether a discrepancy, suggesting new physics, exists between the Standard Model and experimental results. This calculation can be expressed as an integral over Euclidean time of a current-current correlator $G(t)$, where $G(t)$ can be calculated using lattice QCD or, with dispersion relations, from experimental data for $e^{+}{e}^{-}\to \text{mbox}hadrons$. The BMW/DMZ collaboration recently presented a hybrid approach in which $G(t)$ is calculated using lattice QCD for most of the contributing $t$ range, but using experimental data for the largest $t$ (lowest energy) region. Here we study the advantages of varying the position $t=t_1$ separating lattice QCD from data-driven contributions. The total LOHVP contribution should be independent of $t_1$, providing both a test of the experimental input and the robustness of the hybrid approach. We use this criterion and a correlated fit to show that Fermilab/HPQCD/MILC lattice QCD results from 2019 strongly favour the CMD-3 cross-section data for $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ over a combination of earlier experimental results for this channel. Further, the resulting total LOHVP contribution obtained is consistent with the result obtained by BMW/DMZ, and supports the scenario in which there is no significant discrepancy between the experimental value for $a_{\mu }$ and that expected in the Standard Model. We then discuss how improved lattice results in this hybrid approach could provide a more accurate total LOHVP across a wider range of $t_1$ values with an uncertainty that is smaller than that from either lattice QCD or data-driven approaches on their own.

    ↳ hep-lathep-phPRD(2025)·6 citations
33. 33*

    Mode analysis of Nambu-Goldstone modes in U(1) charged first-order relativistic viscous hydrodynamics

    Atsuhisa Ota🇨🇳

    We conduct a mode analysis of a general $U(1)$-charged first-order relativistic hydrodynamics within the framework of effective field theory for dissipative fluids in flat Minkowski spacetime. We derive the most general quadratic action for hydrodynamic modes, including stochastic noise, and analyze the corresponding dispersion relations in a consistent gradient expansion. We argue that spontaneous breaking of spacetime symmetry arises in the presence of a local thermal state specified by a local timelike four-vector. We demonstrate that hydrodynamical perturbations can be identified as Nambu-Goldstone (NG) modes, analogous to their embedding in global $U(1)$-invariant theories. We find that frame-invariant combinations of hydrodynamic transport coefficients determine the first-order dispersion relations in the low-energy limit, making the mode analysis manifestly independent of the choice of hydrodynamic frame. Assuming local Kubo-Martin-Schwinger (KMS) symmetry and unitarity of the underlying UV theory, we show that first-order hydrodynamics is stable if the enthalpy density is positive.

    ↳ hep-thcond-mat.stat-mechgr-qchep-ph+1PRD(2026)·4 citations
34. 34*

    A two-body femtoscopy approach to the proton-deuteron correlation function

    Juan M. Torres-Rincon🇪🇸 · Angels Ramos🇪🇸 · Joel Rufí🇪🇸

    The proton-deuteron correlation function measured by the ALICE collaboration in high multiplicity p+p collisions shows a momentum dependence which is in contradiction with the predictions of the Lednický-Lyuboshitz formalism of the two-body interaction. This result motivated a more sophisticated three-body description in terms of a composite deuteron. Encouraged by the good description of other deuteron observables in the context of heavy-ion collisions, we revisit this correlation function under the two-body approximation without relying on the Lednický-Lyuboshitz approximation, but using the solution of the Schrödinger equation by incorporating both strong and Coulomb interactions. The two-body description provides a reasonable agreement to ALICE data for natural values of the source size. Interpreting the previously assumed attractive character of the $(L,S)=(0,3/2)$ channel of the $pd$ interaction into a more-likely repulsion, the results agree better not only with the ALICE measurements but also with recent STAR data in Au+Au collisions.

    ↳ nucl-thhep-phnucl-exPRC(2025)·18 citations
35. 35*

    Progress on Holographic Vacuum Misalignment

    Ali Fatemiabhari🇬🇧 · Daniel Elander🇵🇹 · Maurizio Piai🇬🇧

    We summarise highlights from an ongoing research programme that aims, in the long run, at the ambitious goal of building a realistic, complete holographic composite-Higgs model. This contribution focuses on vacuum misalignment, by showing how to unify its description, as a phenomenon arising from weak coupling considerations, in the holographic description of a strongly coupled field theory in terms of a dual gravity theory. This is achieved by a non-trivial treatment of boundary-localised terms in the gravity action. The gravity backgrounds considered are completely regular and smooth. We provide numerical examples showing that the mass spectrum of particles in the four-dimensional theory is free of pathologies, and that a small hierarchy arises naturally, between the light states that, in this simplified set up, are analogous to the standard-model particles, and all the other, new composite states emerging in the strongly coupled theory.

    ↳ hep-lathep-phhep-thPoS(2025)·0 citations
36. 36*

    Quantum Inhomogeneous Field Theory: Unruh-Like Effects and Bubble Wall Friction

    Jeongwon Ho🇰🇷 · O-Kab Kwon🇰🇷 · Sang-Heon Yi🇰🇷

    In this paper, we study a free scalar field in a specific (1+1)-dimensional curved spacetime. By introducing an algebraic state that is locally Hadamard, we derive the renormalized Wightman function and explicitly calculate the covariantly conserved quantum energy-momentum tensor up to a relevant order. From this result, we show that the Hadamard renormalization scheme, which has been effective in traditional quantum field theory in curved spacetime, is also applicable in the quantum inhomogeneous field theory. As applications of this framework, we show the existence of an Unruh-like effect for an observer slightly out of the right asymptotic region, as well as the vanishing of quantum frictional effect in the leading order ($e^{-bx}$) on the bubble wall expansion during the electroweak phase transition in the early universe.

    ↳ hep-thgr-qchep-phJHEP(2025)·3 citations
37. 37*

    Precise prediction of the decay rate for ${\eta }_b\to \gamma \gamma$ from lattice QCD

    Brian Colquhoun🇬🇧 · Christine T. H. Davies🇬🇧 · G. Peter Lepage🇺🇸

    We calculate the decay rate for ${\eta }_b\to \gamma \gamma$ in lattice QCD for the first time, providing a precise prediction for the Belle II experiment. Our calculation includes $u$, $d$, $s$ and $c$ quarks in the sea, using gluon field configurations generated by the MILC collaboration, at three values of the lattice spacing from $0.06\mathrm{fm}$ to $0.03\mathrm{fm}$. All quarks are treated in the Highly Improved Staggered Quark formalism, which enables us to reach the $b$ quark mass for our valence quarks on these fine lattices. We calculate quark-line connected correlation functions only. By working at additional heavy quark masses between those of $c$ and $b$ we map out the behaviour of the ratio $f_{{\eta }_h}/(M_{{\eta }_h}^2{F}_{{\eta }_h}(0,0))$, where $f$ is the decay constant, $M$, the mass and $F(0,0)$, the form factor for decay to two on-shell photons for the pseudoscalar heavyonium meson, ${\eta }_h$. This ratio takes the approximate value 0.5 in leading-order non-relativistic QCD (NRQCD) but we are able to give a much more accurate analysis than this. Focussing on the $b$ quark mass, we find a ratio of $0.467(11)$, giving $\Gamma ({\eta }_b\to \gamma \gamma )=0.559(32{)}_{\text{fit}}(1{)}_{\text{syst}}\mathrm{keV}$. Combined with a value for the branching fraction from NRQCD, our result can be used to determine the total width of the ${\eta }_b$ with a $6\%$ uncertainty.

    ↳ hep-lathep-phPRD(2025)·5 citations
38. 38*

    A New Class of Three Nucleon Forces and their Implications

    V. Cirigliano🇺🇸 · M. Dawid🇺🇸 · W. Dekens🇺🇸 · S. Reddy🇺🇸

    We identify a new class of three-nucleon forces that arises in the low-energy effective theory of nuclear interactions including pions. We estimate their contribution to the energy of neutron and nuclear matter and find that it can be as important as the leading-order three-nucleon forces previously considered in the literature. The magnitude of this force is set by the strength of the coupling of pions to two nucleons and is presently not well constrained by experiments. The implications for nuclei, nuclear matter, and the equation of state of neutron matter are briefly discussed.

    ↳ nucl-thastro-ph.HEhep-lathep-phPRL(2025)·16 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.