Tue·Jan 20, 2026Tuesday·January 20, 2026

1. 01*

   Minkowski Space Dynamics and Light-Front Projection

   Wayne de Paula🇧🇷 · Tobias Frederico🇧🇷

   We explore the connection between the four-dimensional Minkowski-space Bethe-Salpeter equation and its light-front projection, emphasizing the implications for bound-state dynamics. Our approach incorporates dressed particles, such as quarks, via the integral representation of the corresponding propagator. We analyze the light-front dynamics of the valence component of the physical state using a hierarchical set of Green's functions, which reveals its coupling to higher Fock components when dressed particles are considered. We also present the light-front Faddeev-Bethe-Salpeter equations for three-body systems with dressed constituents. Furthermore, we discuss formal developments that are central to connecting the three-dimensional light-front dynamics onto the null-plane and the four-dimensional Minkowski-space framework, based on the Nakanishi integral representation. Selected applications to hadron structure are also reviewed.

   hep-phhep-thnucl-thEur.Phys.J.ST(2026)·2 citations
2. 02*

   Testing a Linear Relation: Short-Range Correlations and the EMC Effect for Gluons and Quarks in Nuclei

   Shu-Man Hu🇨🇳 · Wei Wang🇨🇳 · Ji Xu🇨🇳 · Xing-Hua Yang🇨🇳 · Shuai Zhao🇨🇳

   In this work, we focus on the possible linear relation between short-range correlations (SRCs) and the EMC effect for partons in nuclei. First, we test a linear relationship pertaining to gluons in bound nuclei; it is manifested as a correlation between the slope of the reduced cross section ratio in deep inelastic scattering (DIS) and the cross section of sub-threshold $J/\psi$ photoproduction. For comparison, the results from four different global analyses groups of nuclear parton distribution functions (nPDFs) are utilized. These results show a good linear correlation between the gluons in bound nuclei and the slope of the reduced cross section ratio, consistent with the possible presence of nuclear effects in the gluon distributions. Second, we investigate the linear relationship of quarks in the proton-induced Drell-Yan process. The corresponding results for quarks show strong sensitivity to the parameterization forms adopted by the different groups. These findings enhance our understanding of the substructure in bound nuclei and provide valuable reference for future global fitting of nPDFs.

   hep-phCPC(2026)·1 citation
3. 03*

   Examining possible doubly topped baryon configurations

   M. Shekari Tousi🇮🇷 · K. Azizi🇮🇷

   We present a comprehensive theoretical assessment of the masses of possible baryonic configurations characterized by the presence of two heavy top quarks, including ${\Xi }_{ttu}$, ${\Xi }_{ttd}$, ${\Omega }_{tts}$, ${\Omega }_{ttc}$, and ${\Omega }_{ttb}$ systems. This analysis is rigorously executed within the specialized framework of two-point $\mathrm{QCD}$ sum rules, focusing on their predicted ground state masses. Our interest in these systems arises from recent CMS and ATLAS reports indicating a pseudoscalar excess close to $t\bar{t}$ threshold. Our evaluation incorporates both perturbative terms and nonperturbative effects, including condensate contributions up to dimension eight. Based on our results, the extracted central masses for all channels are slightly above the sum of the constituent quark masses, which is consistent with the inherent uncertainties of the method. These quantitative predictions provide a useful first-principle theoretical reference, which may help future experimental searches for such heavy configurations at the LHC and inform sensitivity studies at next-generation facilities such as the FCC.

   hep-phhep-exhep-latInt.J.Theor.Phys.(2026)·2 citations
4. 04*

   Prospects for discovering strongly decaying doubly heavy $T_{bc}$ tetraquark states at LHCb

   Mingjie Feng🇨🇳 · Yiming Li🇨🇳 · Hua-Sheng Shao🇫🇷

   We investigate the discovery potential of the $T_{bc}$ state with $J^P=0^{+}$ in proton-proton ($pp$) collisions at LHCb at a center-of-mass energy of $\sqrt{s}=13\mathrm{TeV}$. The study focuses on the decay channel $T_{bc}\to B^{-}{D}^{+}$. A phenomenological approach is employed to construct the background model based on the associated production of $B$ and $D$ mesons, incorporating previously published LHCb results. Background processes are simulated using $\text{MadGraph5\_aMC@NLO}$ and $\text{Pythia8.3}$. We explore the parameter space of the $T_{bc}$ mass, width, production cross section, and the effective double-parton scattering cross section (${\sigma }_{\mathrm{eff}}$) relevant for the $BD$ meson background. The integrated luminosity required for a $5\sigma$ discovery at LHCb is evaluated under various assumptions. In particular, we consider three representative $T_{bc}$ production cross section scenarios: an optimistic estimate of $103\mathrm{nb}$, an intermediate value of $18\mathrm{nb}$ obtained by scaling from the $T_{cc}^{+}$ production cross section, and a conservative lower bound of $0.3\mathrm{nb}$. We find that a $5\sigma$ observation is achievable for a production cross section of $103\mathrm{nb}$, which is expected to be within reach during Run~4. In contrast, the more realistic cross section estimate of $18\mathrm{nb}$ requires the full Run~5 dataset ($300{\mathrm{fb}}^{-1}$) under the most favorable parameter choices. For the conservative scenario, no significant signal would be observable even with $300{\mathrm{fb}}^{-1}$. In addition, we estimate the minimum observable $\sigma (T_{bc})\times BR(T_{bc}\to B^{-}{D}^{+})$ for a $5\sigma$ discovery under different luminosity scenarios, providing guidance for future experimental searches at LHCb.

   hep-phhep-exCPC(2026)·0 citations
5. 05*

   Neutral scalar pair productions through $W$-boson fusion at multi--TeV muon colliders

   Khiem Hong Phan (DTU)🇻🇳 · Quang Hoang-Minh Pham (HCMUS)🇻🇳

   Full one-loop electroweak radiative corrections to ${\mu }^{-}{\mu }^{+}\to W^{\pm }{W}^{\mp }\to hh$ in the Standard Model are computed for the first time in this work. We then evaluate neutral scalar pair production through vector boson fusion at multi--TeV muon colliders within Two-Higgs-Doublet Model (THDM). In the phenomenological analysis, the enhancement factor, defined as the ratio of the cross sections for SM-like Higgs pair production in the THDM with respect to the corresponding ones in the SM, is examined over the viable regions of the parameter space in the Type-X and Type-Y THDMs. Our findings show that this ratio can reach a factor of $3$ in several regions within the valid parameter space of the Type-X THDM, whereas it ranges from $0.91$ to $0.96$ over the entire parameter space of the Type-Y THDM. Finally, we scan the cross sections for double CP-odd Higgs production over the updated parameter space of the Type-X and Type-Y THDMs. In the Type-Y case at $\sqrt{s}=10$~TeV with an integrated luminosity of $\mathcal{L}=10000{\text{fb}}^{-1}$, CP-odd Higgs pair production in the $t\bar{t}b\bar{b}$ final state, with subsequent top-quark decays into leptons and bottom quarks taken into account, can be tested with a statistical significance exceeding the $2\sigma$ level at several viable parameter points.

   hep-phCPC(2026)·0 citations
6. 06*

   Open charm production and ${\Lambda }_c^{+}/D^0$ ratio in pp and Au+Au collisions at the RHIC

   Bijun Fan🇨🇳 · Chao Zhang🇨🇳 · Liang Zheng🇨🇳 · Shusu Shi🇨🇳

   We study open charm hadrons production in pp and Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}=200$~GeV using an improved a multi-phase transport (AMPT) model. Specifically, we show the transverse-momentum spectra and nuclear modification factors $R_{\mathrm{AA}}$ of $D^0$ mesons and ${\Lambda }_c^{+}$ baryons, as well as the ${\Lambda }_c^{+}/D^0$ ratio in pp and Au+Au collisions. The results obtained from the AMPT model simulations are compared with the STAR experimental data and found to be consistent. We further investigate the ${\Lambda }_c^{+}/D^0$ ratio by evaluating contributions from coalescence, fragmentation, and the combined coalescence+fragmentation mechanisms, and we find that fragmentation alone underestimates the pronounced enhancement in Au+Au relative to pp at low and intermediate $p_{\mathrm{T}}$, whereas the coalescence+fragmentation mechanism reproduces the observed trend significantly better. These results indicate that coalescence plays a key role in charm baryon productions and helps constrain the relative importance of different hadronization mechanisms in the ultra-relativistic nuclear collisions.

   hep-phnucl-thPRC(2026)·1 citation
7. 07*

   Forbidden dark matter assisted by first-order phase transition and associated gravitational waves

   Satyabrata Mahapatra🇮🇳 · Partha Kumar Paul🇮🇳 · Narendra Sahu🇮🇳

   We propose a simple yet testable framework for light fermion dark matter (DM) with mass in the MeV--GeV range, charged under a dark $U(1{)}_D$ gauge symmetry. Before symmetry breaking, DM annihilates excessively into massless dark gauge bosons, resulting in an under-abundant relic and hence creating severe tension with cosmic microwave background (CMB) and indirect detection constraints. This is naturally remedied by a strongly first-order phase transition (FOPT) in the dark sector, triggered by a scalar field $\Phi$, which gives rise to masses for the dark gauge boson ($X_D$) and the physical scalar ($\varphi$). To achieve the correct relic abundance while evading indirect detection constraints, the $s$-wave annihilation channel $\chi \bar{\chi }\to X_D\varphi$ is strictly maintained in the kinematically forbidden regime. Crucially, due to the $U(1{)}_D$ gauge structure, the usual $\chi \bar{\chi }\to \varphi \varphi$ annihilation is strictly absent at tree level and only arises at the one-loop level. Within this framework, we explore two distinct possibilities. When the loop-induced $\chi \bar{\chi }\to \varphi \varphi$ channel is also kinematically forbidden, it predominantly determines the relic density. Conversely, when the $\chi \bar{\chi }\to \varphi \varphi$ channel is kinematically allowed, a rich interplay emerges between the tree-level forbidden $\chi \bar{\chi }\to X_D\varphi$ process and the loop-level allowed $\chi \bar{\chi }\to \varphi \varphi$ process, with the dominant contribution being dictated sensitively by the DM mass and gauge coupling. The late-time annihilations are highly suppressed in both of these channels, either by the energetic threshold of the forbidden channel or the $p$-wave velocity suppression of the loop-induced $\chi \bar{\chi }\to \varphi \varphi$ final state process, rendering the scenario entirely safe from CMB and indirect search bounds...

   hep-phastro-ph.CO5 citations
8. 08*

   Molecular pentaquarks composed of a ground-state octet baryon and a $P-$wave anticharmed meson

   Yu-Yue Cui🇨🇳 · Rui Chen🇨🇳 · Qi Huang🇨🇳

   In this work, we investigate the interactions between an excited anticharm meson doublet $({\bar{D}}_1,{\bar{D}}_2^{\ast })$ and ground-state octet baryons $(N,\Lambda ,\Sigma ,\Xi )$ with the aim of identifying possible molecular pentaquark states. A systematic analysis is performed within the one-boson-exchange model, which incorporates both $S$ and $P$-wave interactions, $S$-$D$ mixing, and coupled-channel effects. By solving the Schrödinger equations, we can predict a rich spectrum of loosely bound anticharm molecular pentaquarks with strangeness $|S|=0,1,2$. Our results provide specific quantum number assignments and mass range predictions to guide future experimental searches at facilities such as LHCb and Belle II. The discovery of such states would significantly enrich the hadron spectrum and serve as a critical test of theoretical models for hadronic interactions.

   hep-phPRD(2026)·1 citation
9. 09*

   PDF at small $x$ in the non-perturbative region

   M. L. Nekrasov🇷🇺

   Parton distribution function (PDF) at small $x$ in a fast-moving proton is investigated within an upgraded parton model that includes parton splitting with branching cascades and parton fusion. In the region of moderately small $x$, we obtain a power-law behavior of the parton density $xf(x)$ with an exponent proportional to the logarithm of the probability of parton splitting. Taking into account parton fusion leads to a nonlinear equation for the PDF. In the region of very small $x$, the phenomenon of saturation of the parton density is detected and a model estimate of its value in this regime is obtained. The results are compared with those obtained previously based on the analysis of equations in logarithmic approximations of perturbative QCD.

   hep-phhep-thPLB(2026)·0 citations
10. 10*

    Sensitivity Analysis of Singlet Vector-Like B Quarks via Photon-Induced Processes at FCC--$\mu p$

    Eda Alici🇹🇷

    This study presents a dedicated and systematic sensitivity analysis of a singlet-type vector-like $B$ quark at an FCC--$\mu p$ collider with a center-of-mass energy of $\sqrt{s}=24.5\mathrm{TeV}$ via photon-induced production mechanisms. The analyses are based on the $B\to Zb$ decay and the lepton decay of the $Z$ boson on a clean and selective final state. In this regard, we observed that the applied kinematic cuts suppress the Standard Model backgrounds by several orders of magnitude while maintain high signal efficiency. Also, the obtained results show that for $\mathcal{L}=1000\mathrm{f}{\mathrm{b}}^{-1}$, even small coupling constant values in the mass range $M_B=2$--$3$~TeV are accessible. In this context, an exclusion limit of $g^{\ast }\simeq 0.12$--$0.17$ at 95\% confidence level and a sensitivity in the range of $g^{\ast }\simeq 0.22$--$0.30$ for the $5\sigma$ discovery region are obtained. Moreover, the calculations indicate that scenarios with smaller $\mathrm{BR}(B\to Zb)$ values via increasing integrated luminosity values can be experimentally tested. As a result, the outputs of the study show that the FCC--$\mu p$ environment offers a unique and powerful discovery potential for vector-like quark searches that go beyond the current LHC limits and complement the decreasing sensitivity of the ep and $e^{+}{e}^{-}$ colliders in the high-mass regime. In this context, the findings suggest that the $\mu p$ colliders can be considered not only as a complementary option for the search of heavy new particles in the future accelerator programme, but also as a strategic discovery tool.

    hep-ph0 citations
11. 11*

    QCD-Like Theories with Different Color Numbers

    Toru Kojo🇯🇵

    Quantum chromodynamics (QCD) with a general number of colors, $\text{Nc}$, provides a powerful theoretical laboratory to explore the dynamics of non-Abelian gauge theories. Although $\text{Nc}=3$ does not look a large number, the $1/\text{Nc}$ expansion provides us with a very useful classification and book-keeping scheme for hadronic processes and sharpens conceptions otherwise obscured in real-world QCD with $\text{Nc}=3$. Important applications are dense QCD matter where the first principle methods for QCD are not available and many conceptual issues remain to be clarified. In this chapter we first review hadrons at large $\text{Nc}$ from the viewpoint of quark-gluon dynamics, and then extend the discussions to hot/dense matter, focusing on confinement-deconfinement aspects. We emphasize how the large-$\text{Nc}$ limit provides a unified organizing principle for hadronic and quark degrees of freedom in regimes where first-principle methods are limited. Two-color and isospin QCD, for which lattice simulations at finite density can be performed for a special reason, is reviewed.

    hep-phnucl-th0 citations
12. 12*

    Investigation of deuteron-like singly bottomed dibaryon resonances

    Yuxuan Du🇨🇳 · Yanyue Pan🇨🇳 · Xinmei Zhu🇨🇳 · Zhiyun Tan🇨🇳 · Hongxia Huang🇨🇳 · Jialun Ping🇨🇳

    We perform a systematical investigation of the existence of the deuteron-like singly bottomed dibaryon resonance states with strangeness $S=-1,-3,-5$ in the chiral quark model. Two resonance states with strangeness $S=-1$ are obtained in the baryon-baryon scattering process. The first candidate is $\Sigma {\Sigma }_b$ in the $\Lambda {\Lambda }_b$ and $N{\Xi }_b^{\ast }$ scattering process, with the resonance energy 6974.22 MeV - 6975.37 MeV and the decay width 14.450 MeV, respectively; the other one is $\Sigma {\Sigma }_b^{\ast }$ in the $N{\Xi }_b$ and $N{\Xi }_b^{\prime }$ scattering process, with the resonance energy 6990.69 MeV - 7008.37 MeV and the decay width 43.790 MeV, respectively. The Root Mean Square (RMS) radius calculation shows that the former tends to be in a compact structure, while the latter tends to be in a molecular structure. Both of these resonance states are worthy of experimental exploration. Furthermore, it should be emphasized that the effect of channel-coupling is of great importance in exploring exotic hadron states, and investigating the scattering process may serve as an effective approach to identifying genuine resonances.

    hep-phhep-exhep-lathep-th+1PRD(2026)·1 citation
13. 13*

    Search for the low-lying excited baryon ${\Sigma }^{\ast }(1/2^{-})$ through process ${\Lambda }_c^{+}\to \Lambda K^0{\pi }^{+}$

    Sheng-Chao Zhang🇨🇳 · Wen-Tao Lyu🇨🇳 · Guan-Ying Wang🇨🇳 · Bo-Qiang Ma🇨🇳 · En Wang🇨🇳

    Motivated by recent BESIII measurements of the singly Cabibbo-suppressed processes ${\Lambda }_c^{+}\to \Lambda K^{+}{\pi }^0$ and ${\Lambda }_c^{+}\to \Lambda K_S^0{\pi }^{+}$, we investigate the process ${\Lambda }_c^{+}\to \Lambda K^0{\pi }^{+}$ by taking into account the contribution from the low-lying excited baryon ${\Sigma }^{\ast }(1/2^{-})$, dynamically generated via the $S$-wave pseudoscalar meson-octet baryon interaction, as well as from the intermediate resonances $K^{\ast }(892)$ and $N(1535)$. Our model successfully reproduces the BESIII ${\pi }^{+}{K}^0$ invariant mass distribution, and predicts a distinct cusp structure around 1.43~GeV in the ${\pi }^{+}\Lambda$ invariant mass distribution, which is associated with the predicted ${\Sigma }^{\ast }(1/2^{-})$. Future high-precise measurements of this process at BESIII, Belle~II, and the proposed Super Tau-Charm Facility experiments will be crucial for testing the existence of ${\Sigma }^{\ast }(1/2^{-})$ and advancing our understanding of the light baryon spectrum.

    hep-phChin.Phys.Lett.(2026)·2 citations
14. 14*

    Can a pseudoscalar with a mass of 365 GeV in the 2HDM explain the CMS $t\bar{t}$ excess?

    Chih-Ting Lu🇨🇳 · Kingman Cheung🇹🇼 · Dongjoo Kim🇰🇷 · Soojin Lee🇹🇼 · Jeonghyeon Song🇰🇷

    We analyze the CMS-reported t tbar excess within conventional Two-Higgs-Doublet Models of Types I, II, X, and Y, using the best-fit pseudoscalar parameters MA = 365 GeV, GammaA over MA = 2 percent, and tan beta = 1.28. Applying theoretical and experimental constraints, including stability, unitarity, perturbativity, flavor constraints, and collider bounds, we find that perturbativity limits the charged and heavy neutral Higgs masses to below about 723 GeV. Flavor constraints exclude Types II and Y, while the remaining parameter space in Types I and X is ruled out by recent t tbar Z measurements from ATLAS and CMS. We conclude that conventional Two-Higgs-Doublet Models cannot explain the observed t tbar excess, although toponium effects in the background modeling may modify this conclusion. This contribution is based on the proceedings of the 18th International Workshop on Top Quark Physics (TOP2025).

    hep-ph1 citation
15. 15*

    Pseudoscalar meson $P\to \tau (\to \pi {\nu }_{\tau },\rho {\nu }_{\tau },\ell {\bar{\nu }}_{\ell }{\nu }_{\tau }){\bar{\nu }}_{\tau }$ decays in the Standard Model and beyond

    Quan-Yi Hu🇨🇳

    In this work, we have conducted a comprehensive and systematic theoretical investigation of the full cascade decays of charged pseudoscalar mesons, specifically $D_s$, $D$, $B$, and $B_c$, into $\tau {\nu }_{\tau }$, followed by the subsequent decay of the $\tau$ via its dominant experimentally reconstructible channels: $\tau \to \pi {\nu }_{\tau }$, $\tau \to \rho {\nu }_{\tau }$, $\tau \to e{\bar{\nu }}_e{\nu }_{\tau }$, and $\tau \to \mu {\bar{\nu }}_{\mu }{\nu }_{\tau }$. Our study is framed within the model-independent low-energy effective field theory approach, which incorporates the most general set of four-fermion operators, including those coupling to right-handed neutrinos. We provide precise Standard Model predictions for differential decay rate as a function of the final-state charged particle energy, develop an innovative and robust methodology for extracting the magnitudes of the new physics couplings using energy moments, and identify and characterize fixed points in the normalized energy distributions. The fixed points are invariant under new physics contributions described by the considered effective Hamiltonian.

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

    Quark sector effects and glueball mass sensitivity estimates in Lorentz-violating supersymmetric QCD-like theories

    Rodrigo Carmo Terin🇪🇸

    The $N=1$ supersymmetric Yang--Mills--Carroll--Field--Jackiw (SYM--CFJ) model is extended to include the quark sector of supersymmetric quantum chromodynamics (SQCD) in the presence of Lorentz--symmetry violation (LSV). The Lorentz--violating data are carried by a spurion chiral superfield whose components define a purely spacelike background vector $v_{\mu }$ and fermionic bilinears, inducing a topological mass scale in the gauge sector. Working within a spurion effective field theory (EFT) and a small--LSV expansion, we classify the allowed parametric dependence of glueball observables on the induced mass scales. Using lattice Yang--Mills (YM) glueball masses only as a reference hadronic scale, we provide parametric sensitivity estimates and naturalness ranges for the topological mass $|v|$ relative to ${\Lambda }_{\mathrm{YM}}$.

    hep-phhep-thAnnals Phys.(2026)·0 citations
17. 17*

    Vacuum Decay Rate in D-dimensional Electroweak theories

    Jingwei Wang🇺🇸 · Ligong Bian🇨🇳

    We present a systematic framework for computing the functional determinant contribution to vacuum decay rates in D-dimensional electroweak theories. It consistently incorporates quantum fluctuations from scalar, fermion, and gauge fields while ensuring rapid convergence even at high angular momenta. Demonstrated through applications to the $D=4$ SMEFT and its $D=3$ thermal counterpart, our method provides a general and efficient tool for analyzing vacuum stability and decay across dimensions in the presence of new physics beyond the Standard Model.

    hep-phhep-th2 citations
18. 18*

    Heavy Quarks in the initial stages of Proton-Ion Collisions

    Gabriele Parisi🇮🇹

    Collisions among heavy ions, like Pb or Au, are a great tool to study the theory of strong interactions, that is Quantum Chromodynamics (QCD). In particular, these experiments are able to give insights on all the complex phases of matter that the theory of QCD allows. In this PhD Thesis we have investigated the initial stages of proton-ion collisions: in particular, we will focus on the first $\sim 0.4$ fm/c ($\sim 10^{-24}$ s) after the collision, which are dominated by very intense gluon fields, in a state called glasma. We investigated the effect of such fields on the dynamics of heavy quarks (charm and beauty) which are created and evolve in this medium. The effect of the initial gluon fields on heavy quarks is quite substantial, in particular we observe that the glasma provokes a $50\%$ dissociation rate on quark-antiquark pairs. Moreover, glasma fields have a large momentum anisotropy, and transmit a large part of such anisotropy to the heavy quarks which evolve in this medium. Finally, we have generalized our study to a non-boost invariant medium, and shown that fluctuations in rapidity do not lead to significant isotropization within glasma timescales.

    hep-phhep-thnucl-th0 citations
19. 19*

    Revisiting Singlet Fermion Dark Matter with a Scalar Portal: Connecting Higgs Phenomenology and Strong Electroweak Phase Transition

    Jaydeb Das🇮🇳 · Saurabh Niyogi🇮🇳 · Tripurari Srivastava🇮🇳

    We investigate a minimal extension of the Standard Model with a real singlet scalar and a singlet Dirac fermion acting as dark matter. Unlike a conventional singlet scalar setup, we assume that the singlet scalar does not acquire a vacuum expectation value at zero temperature. This decouples the scalar mixing angle from the Higgs-portal quartic coupling responsible for the strong first-order electroweak phase transition, allowing it to coexist with current collider and direct-detection constraints. The Higgs-singlet mixing is generated independently through a trilinear portal interaction. We check theoretical consistency conditions, various LHC limits on heavy scalar resonances, dark matter relic abundance, and direct detection bounds to delineate the viable parameter space. We perform a detailed analysis of the electroweak phase transition and show that a strong first-order transition is realized for a selected set of benchmark points. We further compute the resulting stochastic gravitational wave spectra and find that several scenarios yield signals potentially observable at future space-based interferometers. Our results establish a unified and testable framework that connects collider phenomenology, first-order electroweak phase transition, and the resulting production of gravitational waves, along with the dark matter phenomenology, all within a simple renormalizable extension of the Standard Model.

    hep-phJCAP(2026)·7 citations
20. 20*

    Constraining the Higgs potential using multi-Higgs production

    Jia-Le Ding🇨🇳 · Zach Gillis🇺🇸 · Ulrich Haisch🇩🇪 · Brian Moser🇩🇪 · Hai Tao Li🇨🇳 · Davide Pagani🇮🇹 · Luca Rottoli🇮🇹 · Ambresh Shivaji🇮🇳 · Zong-Guo Si🇨🇳 · Jian Wang🇨🇳 · Philipp Windischhofer🇺🇸 · Xiao Zhang🇨🇳 · Dan Zhao🇨🇳

    The Higgs self-couplings remain only weakly constrained by current Large Hadron Collider (LHC) measurements, leaving ample room for physics beyond the Standard Model that could modify the structure of the Higgs potential. Multi-Higgs production processes provide a particularly sensitive probe of deviations in both the Higgs trilinear and quartic self-couplings. In this note, we summarize the current status of next-to-leading-order electroweak (EW) corrections to double-Higgs production computed within the Standard Model Effective Field Theory and Higgs Effective Field Theory frameworks, emphasizing how these calculations introduce sensitivity to the Higgs self-couplings beyond what is accessible at leading order. We discuss the key conceptual and technical differences between the two effective field theory approaches, including their treatment of higher-dimensional operators, renormalization procedures, and the structure of EW~two-loop amplitudes. Despite these differences, both approaches yield broadly consistent constraints, illustrating the complementarity of double- and triple-Higgs measurements. With the high-luminosity LHC and future high-energy colliders on the horizon, these developments and further advances provide an essential foundation for extracting increasingly precise information on the dynamics of EW symmetry breaking.

    hep-phhep-exSciPost Phys.Comm.Rep.(2026)·6 citations
21. 21*

    Scaling laws for amplitude surrogates

    Henning Bahl🇩🇪 · Victor Bresó-Pla🇺🇸 · Anja Butter🇩🇪 · Joaquín Iturriza Ramirez🇫🇷

    Scaling laws describing the dependence of neural network performance on the amount of training data, the spent compute, and the network size have emerged across a huge variety of machine learning task and datasets. In this work, we systematically investigate these scaling laws in the context of amplitude surrogates for particle physics. We show that the scaling coefficients are connected to the number of external particles of the process. Our results demonstrate that scaling laws are a useful tool to achieve desired precision targets.

    hep-phcs.LG13 citations
22. 22*

    Bottom-up approach to describe groomed jet data in heavy-ion collisions

    Liliana Apolinário🇵🇹 · Diogo Costa🇪🇸 · Alba Soto-Ontoso🇪🇸

    The theoretical interpretation of jet observables in heavy-ion collisions is a complex task due to the intricate interplay of perturbative and non-perturbative effects. One way to reduce this complexity is to groom away soft, wide-angle radiation so that perturbative dynamics dominates. Even in this simplified scenario, there are competing explanations for the physical origin of the measured medium-induced modifications. In this paper, we present a minimal approach to compute groomed substructure observables. The core idea is to treat medium effects as an effective energy shift of the hard, vacuum-like substructure. This energy shift includes a gradual onset of colour decoherence effects and thus depends on the jet substructure itself. We first study a NLO-exact dijet configuration in vacuum and apply radiative energy-loss to the two subjets. We find that this minimal setup already captures the narrowing trend of groomed observables but it's not able to quantitatively describe the existing data. Next, we match the NLO matrix-element to a leading-logarithm accurate parton shower and perform a clustering algorithm to recover a two-prong system to which we again apply the energy-loss distribution. Despite its simplicity, the model results in a very good theory-to-data agreement (within $10\%$) for a broad range of observables including both ALICE and ATLAS kinematics. We also examine the discriminating power of groomed jet data in terms of colour decoherence effects and find that substructure-dependent energy loss yields an overall better agreement.

    hep-phhep-exnucl-thEPJC(2026)·7 citations
23. 23*

    Baryon-dark matter coincidence in Randall-Sundrum Model

    Basabendu Barman🇮🇳 · Ashmita Das🇮🇳 · Partha Kumar Paul🇮🇳 · Narendra Sahu🇮🇳 · Rakesh Kumar SivaKumar🇮🇳

    Within the framework of the extra-dimensional Randall-Sundrum set-up, we investigate the freeze-in production of Standard Model (SM) gauge-singlet scalar, fermionic, and massive vector dark matter (DM). Assuming that both the DM and SM fields reside on the IR brane and interact solely through the graviton and radion portal, we demonstrate that the Planck-observed DM relic abundance can be achieved across a wide range of reheating temperatures, all while naturally addressing the hierarchy problem, satisfying constraints from collider and early Universe cosmology. We further show that the same set-up can accommodate TeV-scale leptogenesis capable of generating the observed baryon asymmetry of the Universe. Interestingly, we find that current graviton searches at the Large Hadron Collider (LHC) already impose strong constraints on the reheating temperature in this scenario, providing a complementarity between cosmological and collider probes.

    hep-phastro-ph.COhep-thPRD(2026)·0 citations
24. 24*

    Branching Ratios of $H_{1,2,3}\to {\mu }^{+}{\mu }^{-}$ in the Broken-Phase N2HDM

    T. V. Obikhod🇺🇦 · Ie. O. Petrenko🇺🇦

    Recent evidence from the ATLAS Collaboration for the rare decay $H\to {\mu }^{+}{\mu }^{-}$ provides a unique window into the Higgs boson's coupling to second-generation fermions. In this work, we investigate how this signal can probe physics beyond the Standard Model by computing the branching ratios $B(H_i\to {\mu }^{+}{\mu }^{-})$ for the three CP-even Higgs bosons $H_{1,2,3}$ in the broken-phase Next-to-Two-Higgs-Doublet Model (N2HDM). We incorporate one-loop radiative corrections and analyze deviations from the Standard Model prediction due to modified Yukawa couplings, scalar mixing, and singlet--doublet interactions. By confronting our results with the ATLAS signal strength $\mu =1.4\pm 0.4$, we identify viable regions of the N2HDM parameter space, characterized by tan$\beta$, the singlet vacuum expectation value, and scalar masses, and assess the model's capacity to explain potential enhancements in the dimuon channel. Our study demonstrates that precision measurements of $H\to {\mu }^{+}{\mu }^{-}$ serve as a powerful tool to test extended Higgs sectors and uncover new physics at current and future colliders.

    hep-ph0 citations
25. 25*

    AllShowers: One model for all calorimeter showers

    Thorsten Buss🇩🇪 · Henry Day-Hall🇩🇪 · Frank Gaede🇩🇪 · Gregor Kasieczka🇩🇪 · Katja Krüger🇩🇪

    Accurate and efficient detector simulation is essential for modern collider experiments. To reduce the high computational cost, various fast machine learning surrogate models have been proposed. Traditional surrogate models for calorimeter shower modeling train separate networks for each particle species, limiting scalability and reuse. We introduce AllShowers, a unified generative model that simulates calorimeter showers across multiple particle types using a single generative model. AllShowers is a continuous normalizing flow model with a Transformer architecture, enabling it to generate complex spatial and energy correlations in variable-length point cloud representations of showers. Trained on a diverse dataset of simulated showers in the highly granular ILD detector, the model demonstrates the ability to generate realistic showers for electrons, photons, and charged and neutral hadrons across a wide range of incident energies and angles without retraining. In addition to unifying shower generation for multiple particle types, AllShowers surpasses the fidelity of previous single-particle-type models for hadronic showers. Key innovations include the use of a layer embedding, allowing the model to learn all relevant calorimeter layer properties; a custom attention masking scheme to reduce computational demands and introduce a helpful inductive bias; and a shower- and layer-wise optimal transport mapping to improve training convergence and sample quality. AllShowers marks a significant step towards a universal model for calorimeter shower simulations in collider experiments.

    ↳ physics.ins-detcs.LGhep-exhep-ph7 citations
26. 26*

    Review of hadronic vacuum polarization calculations via $e^{+}{e}^{-}$ measurements

    Zhiqing Zhang🇫🇷

    The discrepancy on the muon anomalous magnetic moment values obtained via a direct measurement and via a data-driven theory determination that uses the experimentally measured hadronic cross section, is among the long standing and most significant deviations from the Standard Model predictions. The recently presented final result of the direct measurement performed at the experiment at Fermilab, with an impressive accuracy of 127 parts-per-billion, further stresses the need for a theory estimate of comparable accuracy. The $e^{+}{e}^{-}$ hadronic cross section is the experimental input to the dispersive integral for the calculation of the hadronic contribution to the $g-2$, which is largely dominated by the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ channel. Precise measurements of the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ cross section with a sub-percent accuracy, in the energy region of the $\rho$-resonance peak, have been performed by several experiments, but the results differ way more than the published accuracies limiting the comparison with the Fermilab direct measurement. New results are expected to become available in the near future from KLOE, CMD-3, SND and BESIII experiments, while a new measurement from the BABAR collaboration is presented today and its impact on the present situation is discussed. This measurement makes use of the entire BABAR data set and adopts a different analysis strategy, with results (still preliminary) largely independent of the results published in the 2009 BABAR publication.

    ↳ hep-exhep-ph3 citations
27. 27*

    Comprehensive study of cosmogenic neutron production in large liquid scintillator detectors

    Yijian Jiang🇨🇳 · Jie Cheng🇨🇳 · Haoqi Lu🇨🇳 · Yaoguang Wang🇨🇳

    Neutrons produced by cosmic ray muons constitute a significant background for underground experiments investigating neutron oscillations, neutrinoless double beta decay, dark matter, and other rare event signals. This work benchmarks measured neutron yields and neutron multiplicities--with a focus on data from the Daya Bay Reactor Neutrino Experiment--against comprehensive simulations using three GEANT4 hadronic physics lists. These simulations are further refined via a TALYS-based adjustment of hadronic cross sections. For the BERT-based models, the adjustment reduces the discrepancy in the total neutron yield from about 20% to approximately 6%, while for the BIC-based models it improves the agreement from roughly 13% to the sub-percent level (~0.3%), indicating a markedly better consistency of the BIC-based models with the experimental data. Nevertheless, a clear tension persists: simulations systematically underproduce single-neutron events while overproducing multi-neutron events. The study establishes a reproducible benchmark for cosmogenic neutron modeling and proposes a targeted refinement strategy--including channel-specific reweighting and intranuclear cascade parameter tuning--to guide future model development.

    ↳ physics.ins-dethep-exhep-ph0 citations
28. 28*

    Stimulated radiation from superradiant scalar cloud in scalar-tensor theory

    Wenyi Wang🇨🇳 · Sousuke Noda🇯🇵 · Taishi Katsuragawa🇨🇳

    Scalar-tensor theories predict fundamental scalar fields of considerable interest in astrophysics and cosmology. We investigate the superradiant instability of scalar clouds around Kerr black holes, showing that stimulated decay generates detectable electromagnetic signals. The growth of the superradiant scalar cloud differs from that of other bosonic fields and depends sensitively on the matter distribution surrounding the black hole, which originates from the scalar-matter coupling realized by the chameleon mechanism in modified gravity theories. In non-uniform matter distributions, stimulated emission from scalar clouds offers an observational signature that distinguishes fundamental scalars from other light bosonic fields.

    ↳ gr-qcastro-ph.HEhep-phhep-thPRD(2026)·0 citations
29. 29*

    Nucleon Resonances in Nuclear Matter and Finite Nuclei

    Horst Lenske🇩🇪

    The theory of nuclear excitations involving nucleon resonances is revisited and significantly extended to asymmetric nuclear matter and higher P- and S-wave $N^{\ast }$ resonances. Excited states of are described as superpositions of particle-hole configurations including $N{N}^{{}^{\prime }-1}$ and $N^{\ast }{N}^{-1}$ configurations. Configuration mixing is taken into account on the one-loop level by solving the generalized $N^{\ast }RPA$ Dyson equation. The underlying coupled channels formalism is derived and response functions is discussed. Applications of the approach are illustrated for charge-exchange modes of asymmetric nuclear matter and finite nuclei. The spectral gross structures of corresponding excitations in finite nuclei are investigated in local density approximation. Applications of the approach to resonance studies by high-energy heavy ion reactions are recapitulated.

    ↳ nucl-thhep-phActa Phys.Polon.B(2026)·0 citations
30. 30*

    Asymptotic Long-Distance Expansion of Euclidean Correlators in Lattice Parton Applications

    Xiangdong Ji🇺🇸 · Yizhuang Liu🇵🇱 · Yushan Su🇺🇸

    Bilinear Euclidean quark and gluon correlators with Wilson links have been used widely for applications of large-momentum effective field theories to computing non-perturbative collinear and soft parton physics. Due to color confinement, these correlators decay exponentially at large spatial distances, a behavior crucial for computing momentum-space Fourier transformations with controlled errors from lattice QCD data. Using heavy-quark effective theory reduction, dispersive analysis, Lorentz symmetry, and heavy-flavor spectra, we determine the leading and next-to-leading asymptotic behaviors and relate the expansion parameters to binding energies of heavy-flavor hadrons. We demonstrate the results through two-loop calculations in ${\varphi }^3$ theory and from the perspective of locality and analyticity. We also study the impact of the asymptotic analysis on realistic lattice QCD data and demonstrate reliable error estimates.

    ↳ hep-lathep-phhep-thnucl-th15 citations
31. 31*

    Signatures of QCD conductivities in heavy-ion collisions

    Akihiko Monnai🇯🇵 · Grégoire Pihan🇺🇸 · Björn Schenke🇺🇸 · Chun Shen🇺🇸

    Dissipative processes are pivotal for understanding the hydrodynamic evolution of hot and dense QCD matter created in relativistic nuclear collisions. The interplay of multiple conserved charges -- net baryon, strangeness, and electric charge -- is of particular interest. We simulate the longitudinal hydrodynamic evolution with the three diffusion currents in a hydrodynamic model with a lattice-QCD-based equation of state, NEOS-4D, and estimate rapidity distributions including diffusive corrections to the phase-space distribution in the presence of multiple charges, which ensure charge conservation at particlization. We determine the response of particle yields at midrapidity to changes in the diagonal and off-diagonal conductivities. Inversely, we find that most components of the conductivity matrix can be constrained experimentally using identified particle multiplicities at different collision energies.

    ↳ nucl-thhep-phnucl-exPRC(2026)·2 citations
32. 32*

    Probing Circumstellar Material and Shock Acceleration in Core-Collapse Supernovae with High-Energy Neutrinos

    Yi-Long Duan🇨🇳 · Tuohuniyazi Tuniyazi🇨🇳 · Gang Guo🇨🇳

    We study high-energy (HE) neutrino production from interactions between supernova (SN) ejecta and the surrounding circumstellar material (CSM), focusing on regular Type~II and Type~IIn SNe. Using observationally inferred CSM density distributions, we calculate the resulting neutrino fluxes and examine their dependence on key parameters, including the CSM density normalization $D_{\ast }$, outer radius $R_{\mathrm{csm}}$, proton acceleration efficiency ${ϵ}_p$, and magnetic energy fraction ${ϵ}_B$. Detection prospects are assessed with a binned likelihood analysis for IceCube, indicating that nearby SNe with moderately dense, confined CSM can produce detectable signals, with a typical detection horizon of $\sim 0.1$ - 1 Mpc. For a Galactic SN at $\sim 10$ kpc, high-statistics neutrino data with detailed temporal and spectral information can constrain $D_{\ast }$, $R_{\mathrm{csm}}$, and ${ϵ}_p$ to within a factor of $\sim 10$ or to a precision of $\sim 20\%$, depending on the assumed values of $D_{\ast }$ and $R_{\mathrm{csm}}$. These neutrino signals thus provide a complementary probe of the CSM profile and shock acceleration, alongside traditional electromagnetic observations.

    ↳ astro-ph.HEhep-phPRD(2026)·1 citation
33. 33*

    Does Schwinger's value for the current of created pairs gets modified for long and strong enough pulse?

    E. T. Akhmedov🇷🇺 · P. S. Zavgorodny🇷🇺

    We determine the parametric conditions (pulse strength and duration) under which Schwinger's prediction for the pair-creation current - and therefore the probability - is significantly altered.

    ↳ hep-thhep-phPRD(2026)·1 citation
34. 34*

    Quantum Cosmology in Accelerating Spacetimes II

    S. P. Miao🇹🇼 · N. C. Tsamis🇬🇷 · R. P. Woodard🇺🇸

    This paper is a sequel in which we further analyze the recently derived quantum gravity equations which apply in accelerating cosmological spacetimes and whose solutions should be equivalent to all order re-summations of the perturbative leading logarithms that appear. In particular we study their implications concerning the primordial tensor power spectrum and the gravitational force due to a test source.

    ↳ gr-qchep-phhep-thPRD(2026)·0 citations
35. 35*

    Lattice-QCD validation of hadron mass and trace-anomaly decomposition sum rules

    Dennis Bollweg🇺🇸 · Heng-Tong Ding🇨🇳 · Xiang Gao🇺🇸 · Ran Luo🇨🇳 · Swagato Mukherjee🇺🇸

    We present the first lattice-QCD validation of multiple sum rules associated with quark-gluon decomposition of hadron mass by computing all components from first principles. We achieve this through nonperturbative renormalization of the QCD energy-momentum tensor, including its trace, in a gradient-flow scheme, followed by continuum extrapolations, two-loop matching to the $\overline{\mathrm{MS}}$ scheme, and zero-flow-time extrapolations. These ingredients enable a direct and simultaneous verification, in a common renormalization scheme and scale, of multiple energy-density-based and trace-based mass decomposition sum rules proposed in the literature. We demonstrate the framework for the ${\eta }_c$ and $J/\psi$ charmonia using three fine lattice spacings with a physical strange-quark and near-physical up- and down-quark masses. We present the first lattice-QCD results for the gravitational form factor $\bar{C}$. We find sizable gluonic contributions to charmonia masses at the hadronic scale, $\sim 15\%$ in the Lorcé and Metz-Pasquini-Rodini decompositions. The trace-anomaly contribution in the Ji sum rule is $\sim 6\%$, while the gluonic component of the trace anomaly in the Hatta-Rajan-Tanaka sum rule is $\sim 35\%$. The method is general and can be straightforwardly adopted for lattice-QCD calculations of mass and spin decompositions as well as gravitational form factors of other hadrons and nuclei.

    ↳ hep-lathep-phnucl-thPRL(2026)·2 citations
36. 36*

    Plunge-Merger-Ringdown Tests of General Relativity with GW250114

    Leonardo Grimaldi🇩🇪 · Elisa Maggio🇩🇪 · Lorenzo Pompili🇩🇪 · Alessandra Buonanno🇩🇪

    The binary black hole signal GW250114, the clearest gravitational wave detected to date, offers a unique opportunity to test general relativity in the relativistic strong-gravity regime. How well does GW250114 agree with Einstein's predictions in the plunge-merger-ringdown stage? To address this point, we constrain deviations from general relativity across the plunge-merger-ringdown stage of spin-precessing binaries with a parametrized waveform model within the effective-one-body formalism. We find that deviations from the peak gravitational-wave amplitude and instantaneous frequency of the $(\ell ,|m|)=(2,2)$ mode are constrained to about $10\%$ and $4\%$, respectively, at $90\%$ credible level. These constraints are, respectively, two and four times more stringent than those obtained by analyzing GW150914. We also constrain, for the first time, the instantaneous frequency of the $(\ell ,|m|)=(4,4)$ mode at merger to about $6\%$, and the time at which the gravitational-wave amplitude peaks to about $5\mathrm{ms}$. These results are the most precise tests of general relativity in the nonlinear regime to date, and can be employed to constrain extensions of Einsten's theory.

    ↳ gr-qchep-phPRD(2026)·6 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.