Thu·Dec 11, 2025Thursday·December 11, 2025

1. 01*

   Long-Lived-Particle Signals of a Composite Hidden Sector through the Neutrino Portal

   Aqeel Ahmed🇩🇪 · Zackaria Chacko🇺🇸 · Niral Desai🇺🇸 · Sanket Doshi🇺🇸 · Can Kilic🇺🇸 · Saereh Najjari🇩🇪 · Ram Purandhar Reddy Sudha🇺🇸

   We explore the signals of a scenario in which the composite states of a strongly coupled hidden sector couple to the Standard Model through the neutrino portal, giving rise to the neutrino masses. We consider a framework in which the hidden sector is conformal in the ultraviolet and the compositeness scale lies below the weak scale. If the lightest composite state in the hidden sector is a scalar, its decay rate back to the Standard Model is suppressed by angular momentum considerations and can naturally be small, giving rise to long-lived particle signals. We determine the current constraints on this class of models and explore the reach of future collider and beam dump searches. We find that FASER, SHiP, and Belle II can potentially probe a significant part of the unexplored parameter space.

   hep-phhep-exJHEP(2026)·4 citations
2. 02*

   A novel two loop inverse seesaw model

   Gonzalo Benítez-Irarrázabal🇨🇱 · Rocío Branada Balbontín🇨🇱 · Cesar Bonilla🇨🇱 · A. E. Cárcamo Hernández🇨🇱 · Sergey Kovalenko🇨🇱 · Juan Marchant González🇨🇱

   We propose a Standard Model (SM) extension where neutrinos get masses through a two-loop inverse seesaw mechanism. This naturally explains the smallness of the neutrino masses and allows seesaw mediators to be at the TeV scale with testable phenomenology. The model adds two real singlet scalars and four electrically neutral leptons to the SM. The extension considers the existence of two global Abelian symmetries, a continuous $U(1)$ and a discrete $Z_3$. The latter, remains unbroken after spontaneous symmetry breaking and forbids tree-level and one-loop neutrino masses, and stabilizes the dark matter (DM) candidates. This setup accommodates neutrino-oscillation data, yields two pseudo-Dirac heavy pairs with small active-sterile mixing, and predicts an effective Majorana mass $m_{ee}$ in the $2.1$-$4.4$ meV range for normal ordering. Charged-lepton flavor violation is naturally suppressed yet testable: for a representative benchmark we obtain BR$(\mu \to e\gamma )\simeq 1.6\times 10^{-14}$, with correlated signals in $\mu \to eee$ and $\mu$-$e$ conversion within next-generation experimental reach. Altogether, the radiative origin of neutrino masses links low-energy flavor observables to collider signatures, delineating discovery targets for MEG II, Mu2e/COMET, and the HL-LHC and distinguishing this framework from conventional inverse- and radiative-seesaw models. Moreover, the $Z_3$ guarantees a stable DM candidate, either scalar ($\rho$) or fermionic ($\Omega$). Then, here we analyze and identify the viable parameter space that is consistent with the observed DM relic abundance for both situations.

   hep-phJHEP(2026)·2 citations
3. 03*

   Relic Density Topology as a Discriminatory Tool: A Comparative Analysis of IDM, MSSM, and NMSSM Dark Matter

   Mohid Farhan🇵🇰

   This study proposes a diagnostic mechanism based on the relic density topology to discriminate between the Inert Doublet Model (IDM), the Minimal Supersymmetric Standard Model (MSSM), and the Next-to-Minimal Supersymmetric Standard Model (NMSSM). Using a unified numerical scan with micrOMEGAs over the heavy-mass regime ($m_x>300$ GeV), we contrast the phenomenological profiles of these frameworks. We demonstrate that the IDM admits a broad, stable viability plateau driven by efficient gauge couplings, while the MSSM and NMSSM typically overproduce dark matter, reaching the Planck relic density only through narrow, fine-tuned resonance channels. A quantitative fine-tuning measure reveals the IDM's viable parameter space is an order of magnitude more natural than its SUSY counterparts. Furthermore, by examining the thermal decoupling epoch ($z_f$) and the CMB energy-injection parameter ($p_{ann}$), we confirm that all identified viable regions are consistent with cosmological observations, and that the models exhibit different thermal history scenarios for the Universe. Our findings establish a multi-faceted discriminative framework: the IDM is characterized by a robust plateau and low fine-tuning, the MSSM by a sharp slepton-mediated annihilation dip, and the NMSSM by a diluted signature due to singlino admixture. The discovery of a heavy WIMP without sharp resonance features would therefore phenomenologically favor scalar doublet extensions over minimal supersymmetric frameworks.

   hep-ph0 citations
4. 04*

   Curvaton-assisted hilltop inflation

   Wen-Yuan Ai🇦🇹 · Stephen F. King🇬🇧 · Xin Wang🇬🇧 · Ye-Ling Zhou🇨🇳

   Following the recent Atacama Cosmology Telescope (ACT) results, we consider hilltop inflation where the inflaton is coupled to a curvaton, simultaneously addressing two main challenges faced by conventional hilltop inflation models: the initial-value problem; and their viability for sub-Planckian field values. In standard single-field hilltop inflation, the inflaton must start extremely close to the maximum of the potential, raising concerns about the naturalness of the initial conditions. We demonstrate that the curvaton field not only significantly relaxes the initial-value tuning required for hilltop inflation, but also opens up parameter space through modifying the curvature perturbation power spectrum, reviving the quartic hilltop inflation model in the sub-Planckian regime. We find viable parameter space consistent with the recent cosmological observations.

   hep-phastro-ph.CO1 citation
5. 05*

   System Energies for Pentaquark Family Using Thomas-Fermi Quark Model

   Suman Baral🇺🇸 · Bipin Aryal🇳🇵 · Mohan Giri🇺🇸 · Artem Denisenkoa🇺🇸 · Gopi Chandra Kaphle🇳🇵 · Walter Wilcox🇺🇸

   This study calculates the system energies of families of pentaquarks, $uudc\bar{c}$, starting from 5 quarks up to 70 using Thomas-Fermi statistical quark model. The model assumes spherical symmetry with the particles continuously distributed with varying densities and boundaries. The particles interact with Coulombic forces and a discontinuity in the light quark density function is energetically favored. Total energies of the system are calculated for each multiquark system and compared to determine family stability characteristics. A remarkable stability for multiquark combinations with multiples of four pentaquarks, which we term an icosaquark, is identified. The first icosaquark system is found to have lowest energy per quark, suggesting stability of a system consisting of four charm, four anticharm and twelve light quarks.

   hep-phnucl-th0 citations
6. 06*

   Unfolding quantum entanglement from $h\to Z{Z}^{\ast }\to jj\ell \ell$ at a muon collider

   Songshaptak De🇮🇳 · Atri Dey🇸🇪 · Tousik Samui🇮🇳

   We explore the potential to study quantum entanglement through Bell-type inequalities in Higgs boson decays at a future muon collider. Our analysis focuses on the channel ${\mu }^{+}{\mu }^{-}\to \nu \bar{\nu }h\to \nu \bar{\nu }Z{Z}^{\ast }$, with one $Z$ decaying to charged leptons and the other decaying hadronically into jets. We study the violation of the CGLMP inequality using the optimal Bell operator for the bipartite qutrit system from $h\to Z{Z}^{\ast }$. The entanglement measure ${\mathcal{I}}_3$ is constructed from spin-correlated angular observables of the $Z$ decay products. An unfolding method on the angular variables is applied to correct for hadronization and detector effects, recovering the advantage of the hadronic mode with higher event yield and reduced uncertainty. The study is performed at 1, 3, and 10 TeV centre-of-mass energies, assuming 10 ab${}^{-1}$ integrated luminosity for each case. At 1 TeV, we use a boosted decision tree for signal isolation, while at higher energies, simple cut-based analyses are sufficient. We find clear Bell inequality violation with the expected values ${\mathcal{I}}_3=2.625\pm 0.012$, $2.623\pm 0.004$, and $2.582\pm 0.010$ for the 1, 3, and 10 TeV machines, respectively. Overall, a strong level of entanglement close to the maximum achievable value of 2.9149 for a two-qutrit system can be measured with very small uncertainties due to the large event yield in the hadronic mode.

   hep-ph5 citations
7. 07*

   Insights into Nucleon Resonances via Continuum Schwinger Function Methods

   Peng Cheng🇨🇳 · Langtian Liu🇨🇳 · Ya Lu🇨🇳 · Craig D. Roberts🇨🇳

   The first baryon resonance was discovered in the early 1950s. The Roper resonance joined the collection ten years later. Today, many baryon resonances are known and more are being discovered. As baryons, these states are the most fundamental three-body systems in Nature. They must all be understood, not just the isolated ground state nucleon. This contribution sketches applications of continuum Schwinger function methods to the baryon resonance problem. Whilst spectroscopy is of value, particular emphasis is placed on resonance electroproduction because transition form factors extracted from electroproduction data provide a keen tool for revealing resonance structure.

   hep-phhep-exhep-latnucl-ex+1Acta Phys.Polon.B(2026)·3 citations
8. 08*

   Primordial magnetic field from chiral plasma instability with sourcing

   Murman Gurgenidze🇺🇸 · Andrew J. Long🇺🇸 · Alberto Roper Pol🇨🇭 · Axel Brandenburg🇸🇪 · Tina Kahniashvili🇺🇸

   In an electron-positron plasma, an imbalance in the number of right- and left-chiral particles can lead to the growth of a helical magnetic field through a phenomenon called the chiral plasma instability (CPI). In the early universe, scattering reactions that violate chirality come into thermal equilibrium when the plasma cools below a temperature of approximately $80\mathrm{TeV}$. Since these reactions tend to relax any pre-existing chiral asymmetry to zero as the system approaches equilibrium, the standard lore is that primordial magnetogenesis via the CPI is not viable below $80\mathrm{TeV}$. In this work, we propose that the presence of a source for chirality can allow the CPI to operate even below $80\mathrm{TeV}$, we explore the implications of this scenario, and we derive predictions for the resultant magnetic field helicity using a combination of analytical methods and direct numerical simulation.

   hep-phastro-ph.COPRD(2026)·7 citations
9. 09*

   Finite $V_{2\Delta }$ puzzle in low-multiplicity pp collisions from ultra-long-range azimuthal correlations in the string-shoving model

   Antonio Ortiz🇲🇽 · Dushmanta Sahu🇲🇽 · Gyula Bencedi🇭🇺

   Ultra-long range angular correlations have been recently reported by the ALICE collaboration in pp collisions at $\sqrt{s}=13$ TeV below $\mathrm{d}{N}_{\mathrm{ch}}/\mathrm{d}\eta =7$. The measurements have been performed as a function of the charged-particle multiplicity at midrapidity ($N_{\mathrm{ch}}$ in $|\eta |<0.8$), which is known to be strongly sensitive to local multiplicity fluctuations. The present work investigates the impact of the event-activity estimator on ultra-long range angular correlations. The study is conducted in the framework of PYTHIA8 with the string shoving mechanism since it gives a non-zero elliptic flow coefficient, $V_{2\Delta }$. The analysis is conducted as a function of $N_{\mathrm{ch}}$, the number of parton-parton scatterings ($N_{\mathrm{mpi}}$) and flattenicity. Surprisingly, for ultra-long range correlations, pp collisions with $N_{\mathrm{mpi}}=1$ (dijets) seems to be the most sensitive to string shoving. The effect diminishes with increasing $N_{\mathrm{mpi}}$. While in data, within uncertainties, $V_{2\Delta }$ exhibits a weak multiplicity dependence; the string shoving mechanism gives a $V_{2\Delta }$ that decreases with the increase in $N_{\mathrm{ch}}$. The present work therefore supports the picture stating that mechanisms such as string shoving might explain the low multiplicity limit, whereas, hydro becomes relevant in high-multiplicity pp collisions. This work also suggests that flattenicity might be more effective than $N_{\mathrm{ch}}$ to better handle non-flow effects.

   hep-phPRD(2026)·0 citations
10. 10*

    Nucleon decays into three leptons: contact contributions

    Yi Liao🇨🇳 · Xiao-Dong Ma🇨🇳 · Xiang Zhao🇨🇳

    Baryon number violating (BNV) nucleon decays into three leptons provide a unique probe of BNV interactions beyond the conventional two-body modes involving a single lepton and a light meson. In a previous work [Nucleon decays into three leptons: noncontact contributions, arXiv:2512.02692.], two of us analyzed the noncontact contributions to these decays arising from dimension-6 (dim-6) operators within the low-energy effective field theory (LEFT), and found that they are severely suppressed due to stringent constraints on these dim-6 operators. In this work, we continue this endeavor by systematically investigating the contact contributions originating from dim-9 LEFT operators. We construct a complete basis of dim-9 operators relevant to these processes, and subsequently match them onto chiral perturbation theory to calculate their decay widths. By employing existing experimental data, we derive stringent constraints on the relevant operators. In addition, we present the analysis of an ultraviolet-complete model to demonstrate its connection with our theoretical framework, thereby facilitating further studies of these exotic nucleon decays in upcoming neutrino experiments with large fiducial masses.

    hep-phJHEP(2026)·1 citation
11. 11*

    Dark Matter and Dark Energy in Three-Higgs Doublet Model

    Mohid Farhan🇵🇰 · Ibtehaj Hassan · Muhammad Usman · Noraiz Tahir

    This article discusses the incorporation of dark matter and dark energy into a new physics model called the Three-Higgs Doublet Model. Dark matter and dark energy are accommodated as CP-even and $Z_2$-odd scalars in their respective inert doublets. By leveraging a $Z_2$ symmetry to suppress certain interactions, we model the behavior of dark matter. Similarly, by imposing a shift symmetry, dark energy can be mimicked within the same framework for the current cosmic epoch. The dark matter relic density is calculated for our model using \texttt{micrOMEGAs}. It is shown that despite the inclusion of dark energy, dark matter relic density can be brought within observational bounds and match existing literature. Furthermore, the one-loop and two-loop Renormalization Group Equations (RGEs) were computed using \texttt{SARAH} to ensure radiative stability over a large range of energies. This study lays the groundwork for a future study of dark matter-dark energy interactions in the early universe and the exploration of different early universe dynamics.

    hep-ph1 citation
12. 12*

    Improved analysis of rare $Z$-boson decays into a heavy vector quarkonium plus lepton pair

    Li Ang🇨🇳 · Dao-Neng Gao🇨🇳

    We improve the theoretical predictions for rare $Z$-boson decays, $Z\to V{\ell }^{+}{\ell }^{-}$ ($\ell =e$ or $\mu$), where $V$ denotes a heavy vector quarkonium including $J/\Psi$, $\Psi (2S)$, and ${\rm Y}(nS)$ with $n=1,2,3$. These processes are thought to be dominated by the electromagnetic fragmentation transition, i.e., $Z\to {\gamma }^{\ast }{\ell }^{+}{\ell }^{-}$ followed by ${\gamma }^{\ast }\to V$. The present study includes all of the relevant tree-level Feynman diagrams, which contribute to these decays in the standard model. Our analysis shows that, for the charmonium final states, the fragmentation transition almost saturates the whole contribution and the other diagrams can be neglected; while for the bottomonium final states, the inclusion of other diagrams can increase their branching fractions by $4\%\sim 9\%$. Further investigation of the differential distributions, especially the angular distributions, indicates that forward-backward asymmetries for final leptons in these processes would be zero in the standard model. Therefore, in future experimental facilities with large number of $Z$-boson events accumulated, studies of these rare $Z$ decays may help both to test the standard model and to probe its interesting extensions.

    hep-phhep-exNPB(2026)·0 citations
13. 13*

    Anomalous Isotopes In Dark Atoms models

    M. I. Balino🇷🇺 · J. Mwilima🇷🇺 · D. O. Sopin🇷🇺 · M. Yu. Khlopov🇫🇷

    In this work, we study some aspects of the dark atom model. We consider a finite-size nucleus to find the wave functions of the bound state of a stable particle with a charge of $-2n$ and helium-4 ${}^{4}H{e}^{++}$. Then we address the problem of calculating the abundance of anomalous isotopes arising from the capture of helium nuclei by dark atoms during Big Bang nucleosynthesis. We use an analogy with the proton-neutron capture process to calculate the reaction cross section and thus determine the concentration of OBe nuclei.

    hep-ph0 citations
14. 14*

    Branching fraction of ${\Xi }_{bc}^{+}\to {\Xi }_c^{+}J/\psi$ in the final-state-interaction approach

    Xiao-Hui Hu🇨🇳 · Cai-Ping Jia🇨🇳 · Ye Xing🇨🇳 · Fu-Sheng Yu🇨🇳

    The process of ${\Xi }_{bc}^{+}\to {\Xi }_c^{+}J/\psi$ is among the most favored modes for searching for bottom-charm baryons. However, its branching fraction has never been studied in theory. In this work, we investigate the branching fraction of ${\Xi }_{bc}^{+}\to {\Xi }_c^{+}J/\psi$ in the final-state-interaction approach, as it is dominated by the color-suppressed non-factorizable contributions. A similar process, ${\Lambda }_b^0\to {\Lambda }^{0}J/\psi$, is used as a control mode to fix the model parameter. Consequently, the branching fraction of ${\Xi }_{bc}^{+}\to {\Xi }_c^{+}J/\psi$ is predicted to be $(1.55_{-0.42}^{+0.50})\times 10^{-4}$. With the production rate of bottom-charm baryons and the detection efficiencies of the final states, it is expected for considerable signal events to observe ${\Xi }_{bc}^{+}$ in the near future.

    hep-phPRD(2026)·4 citations
15. 15*

    Reconciling ALP Dark Matter and Electroweak Baryogenesis through First-Order Electroweak Phase Transition

    Dipendu Bhandari🇮🇳 · Soumen Kumar Manna🇮🇳 · Arunansu Sil🇮🇳

    We show that an axionlike particle (ALP) can simultaneously generate the baryon asymmetry and constitute dark matter through dynamics triggered by a first-order electroweak phase transition (EWPT). In our proposal, the transition briefly reshapes the ALP potential via a temperature-dependent vacuum expectation value of a scalar field $S$, responsible for making the EWPT of first order, inducing a transient mass enhancement of ALP via higher-dimensional $U(1)$-breaking operator(s). This sudden kick generates a large ALP velocity near the onset of EWPT enabling the broadening of relic satisfied parameter space and predict a complementary stochastic gravitational-wave signal from the underlying first-order transition. We further show that the same ALP dynamics can naturally fuel electroweak baryogenesis through its coupling to electroweak anomaly.

    hep-phastro-ph.COhep-th2 citations
16. 16*

    Exploiting Perpendicular Momentum Distributions of Semileptonic Decays: ${\bar{B}}_s^0\to D_s^{+}{\mu }^{-}\bar{\nu }$ as a Case Study

    Charles Earnshaw🇬🇧 · Biljana Mitreska🇬🇧 · Danny van Dyk🇬🇧

    We derive the differential distribution of semileptonic decays with respect to the perpendicular momentum component of the final state hadron. The benefits and shortfalls arising from measurements of these distributions are discussed. Our approach is illustrated on the LHCb measurement of the ${\bar{B}}_s^0\to D_s^{+}{\mu }^{-}\bar{\nu }$ decay distribution where the publicly available data by the LHCb experiment is used in an independent phenomenological analysis for the first time. We extract the CKM element $|V_{cb}|$ and information on the shape of the relevant hadronic form factors from the measurement of the binned rate in the perpendicular momentum component of the hadron.

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

    A Precise ${\alpha }_s$ Determination from the R-improved QCD Static Energy

    Jose M. Mena-Valle🇪🇸

    The strong coupling ${\alpha }_s$ is extracted with high precision through fits to lattice-QCD data for the static energy. Our theoretical framework is based on R-improving the three-loop fixed-order prediction for the static energy: we remove the $u=1/2$ renormalon and resum the associated large infrared logarithms. Combined with radius-dependent renormalization scales (the so-called profile functions), this procedure extends the range of validity of perturbation theory to distances as large as $\sim 0.5$fm. In addition, we resum large ultrasoft logarithms to N${}^3$LL accuracy using renormalization-group evolution. Since the standard four-loop R-evolution treats N${}^4$LL and higher-order contributions asymmetrically, we also incorporate this potential source of bias in our analysis. Our estimate of the perturbative uncertainty is obtained through a random scan over the parameters controlling the profile functions and the implementation of R-evolution. We analyze how the extracted value of ${\alpha }_s$ depends on the shortest and longest distances included in the fit, on the details of the R-evolution procedure, on the fitting strategy itself, and on the accuracy of ultrasoft resummation. From our final analysis, and after evolution to the $Z$ pole, we obtain ${\alpha }_s^{(n_f=5)}(m_Z)=0.1170\pm 0.0009$, a result fully compatible with the world average and with a comparable uncertainty.

    hep-phhep-latPoS(2026)·0 citations
18. 18*

    Photon emission by vortex particles accelerated in a linac

    A. Yu. Murtazin🇷🇺 · G. K. Sizykh🇷🇺 · D. V. Grosman🇷🇺 · U. G. Rybak🇷🇺 · A. A. Shchepkin🇷🇺 · D. V. Karlovets🇷🇺

    We study the photon emission by charged spinless particles with phase vortices and an orbital angular momentum (OAM) projection in longitudinal electric and magnetic fields within the scalar QED. A realistic wave packet of an electron or ion accelerated by a radio-frequency wave locally feels a constant and spatially homogeneous field, which allows us to develop an effective model for losing the angular momentum of the vortex particle due to photon emission. For the fields typical for accelerator facilities, we find that an effective lifetime of the vortex state greatly exceeds the acceleration time. This proves that the acceleration of vortex electrons, ions, muons, and so forth to relativistic energies is possible in conventional linacs, as well as in the wake-field accelerators with higher field gradients, the OAM losses due to the photon emission are mostly negligible, and that the vortex quantum state is highly robust against these losses.

    hep-phphysics.acc-phquant-phPRD(2026)·6 citations
19. 19*

    Do SN 1987A data yield the three neutrino masses?

    Robert Ehrlich🇺🇸

    Currently only upper limits are known for the neutrino masses based on cosmological constraints and direct neutrino mass experiments. This review explores the possibility that SN 1987A might provide actual values for the three neutrino masses and not just upper limits, a possibility first suggested by Ramanath Cowsik in 1988. Cowsik's result depends on the neutrino emissions from SN 1987A being near-simultaneous, i.e., within a time interval $\Delta t<1s.$ Having such a brief burst, however, is contradicted by virtually all supernova neutrino emission models that include a $\Delta t>10s$ cooling phase. Here it is explained why those neutrino emission models may be mistaken, and why the three neutrino masses suggested by the SN 1987A data might be correct even though they are larger than the upper limits implied from cosmology and direct mass experiments.

    hep-phastro-ph.HE0 citations
20. 20*

    Searches for electroweak states at future plasma wakefield colliders

    So Chigusa🇺🇸 · Simon Knapen🇺🇸 · Toby Opferkuch🇮🇹 · Inbar Savoray🇺🇸 · Christiane Scherb🇺🇸 · Weishuang Linda Xu🇺🇸

    We quantify the discovery potential of future multi-TeV plasma wakefield colliders for new electroweak multiplets. We include beam-beam effects through realistic luminosity spectra, comparing five collider configurations: $e^{+}{e}^{-}$ and $e^{-}{e}^{-}$ machines with round- and flat-beams, and a $\gamma \gamma$ collider. The beam-beam effects qualitatively change search strategies relative to idealized mono-energetic lepton colliders, highlighting the importance of the low-energy part of the luminosity spectrum and additional beam-induced initial-state channels. Our results have implications for accelerator R&D priorities, since key electroweak targets may remain accessible even if efficient positron acceleration and flat-beam delivery prove technically challenging at the multi-TeV scale.

    hep-phphysics.acc-ph8 citations
21. 21*

    Constraining Gravitational Dark Matter with LHAASO and Fermi-LAT

    Basabendu Barman🇮🇳 · Arindam Das🇯🇵 · Prantik Sarmah🇨🇳 · Rakesh Kumar SivaKumar🇮🇳

    We use diffuse Galactic high energy gamma ray data from LHAASO and Fermi-LAT to constrain gravitationally produced decaying dark matter (DM). Focusing on four benchmark candidates: a dark photon, a heavy right-handed neutrino (RHN), a pseudo-Nambu-Goldstone boson (pNGB), and a non-minimally coupled scalar we derive bounds on the DM mass and its couplings to the visible sector. For dark photons, RHNs, and pNGBs, the combined data constrain the relevant interaction strength to $\lesssim \mathcal{O}(10^{-30})$ for DM masses $\gtrsim \mathcal{O}$(TeV), while the non-minimally coupled scalar is limited to $\lesssim \mathcal{O}(10^{-10})$. Moreover, photon-dark photon oscillations yield strong constraints for massive dark photon beyond 10 GeV, closing a region of parameter space previously left unconstrained.

    hep-phastro-ph.COPRD(2026)·2 citations
22. 22*

    Neutrinos, B-L Symmetry and the Dark Dimension

    Miguel Montero🇪🇸 · Cumrun Vafa🇺🇸 · Irene Valenzuela🇪🇸

    We consider realizations of a gauged B-L symmetry in the context of the Dark Dimension scenario, where the SM lives on a codimension one brane in 5d spacetime. The B-L can naturally be a bulk gauge symmetery leading to a global symmetry on the SM brane, and have its gauge anomaly canceled by charged bulk modes. This naturally leads to the existence of 3 right-handed neutrinos propagating in the dark dimension. Allowing for Higgsing of B-L by a bulk scalar at the Higgs scale, results in a massive gauge field with $m_{B-L}\sim 100$ GeV and weak coupling $g_{B-L}\sim 10^{-10}$ which is allowed by current bounds. The model also predicts a natural matching $m_{\nu }\sim m_{KK}\sim {\Lambda }^{1/4}$, thereby providing a theoretical explanation for the observed coincidence between neutrino masses and the Dark Energy scale. It also predicts a tower of sterile right-handed neutrinos in the $keV$ mass range.

    ↳ hep-thhep-phJHEP(2026)·5 citations
23. 23*

    The $\mathcal{N}=1$ supersymmetric Pati-Salam models with extra $SU(2{)}_{L_2/R_2}$ gauge symmetry from intersecting D6-branes

    Haotian Huangfu🇨🇳 · Tianjun Li🇨🇳 · Qi Sun🇨🇳 · Rui Sun🇨🇳

    By introducing an extra stack of D6-branes to standard $\mathcal{N}=1$ supersymmetric Pati-Salam models, we extend the landscape of its complete search. In this construction, the $d$-stack of D6-branes is introduced besides the standard $a,b,c$-stacks. More intersections from the extra stacks of D6-branes appear, and thus Higgs/Higgs-like particles arise from more origins. Among these models, we find eight new classes of $\mathcal{N}=1$ supersymmetric Pati-Salam models with gauge symmetries $SU(4{)}_C\times SU(2{)}_L\times SU(2{)}_{R_1}\times SU(2{)}_{R_2}$ and $SU(4{)}_C\times SU(2{)}_{L_1}\times SU(2{)}_R\times SU(2{)}_{L_2}$, where $d$-stack of D6-branes carries the gauge symmetries $SU(2{)}_{R_2}$ and $SU(2{)}_{L_2}$, respectively. The $SU(2{)}_{L_1/R_1}\times SU(2{)}_{L_2/R_2}$ can be broken down to the diagonal $SU(2{)}_{L/R}$ gauge symmetry via bifundamental Higgs fields. In such a way, we for the first time successfully constructed three-family supersymmetric Pati-Salam models from non-rigid D6-branes with extra $d$-stacks of D6-branes as visible sectors. Interestingly, by introducing extra stack of D6-branes to the standard supersymmetric Pati-Salam models, the number of filler brane reduces in general, and eventually the models without any $USp(N)$ gauge symmetry present. This reduces the exotic particles from filler brane intersection yet provides more vector-like particles from $\mathcal{N}=2$ subsector that are useful in renormalization group equation evolution as an advantage. Moreover, interesting degeneracy behavior with the same gauge coupling ratio exists in certain class of models.

    ↳ hep-thhep-phmath-phmath.MPJHEP(2026)·1 citation
24. 24*

    Notes On de-Sitter Mellin Barnes Amplitudes

    Sayantan Choudhury🇮🇳

    In this paper, we create a Mellin space method for boundary correlation functions in de Sitter (dS) and anti-de Sitter (AdS) spaces. We demonstrate that the analytic continuation between AdS${}_{d+1}$ and dS${}_{d+1}$ is encoded in a set of simple relative phases using the Mellin-Barnes representation of correlators. It helps us to determine the scalar three-point and four-point functions and their corresponding Mellin-Barnes amplitudes in dS${}_{d+1}$ space using the known results from AdS${}_{d+1}$ space. The Mellin-Barnes representation reveals the analytic structure of boundary correlation functions over all $d$ and scaling dimensions. In the present discussion, the {\it split representation} have been used as an instrumental technique in particularly the evaluation of bulk Witten diagrams and is suitable to obtain the {\it Conformal Partial Wave decomposition} of tree-level exchange in the bulk Witten diagrams. The equivalent adjustment to the cosmological three-point and four-point function of generic external scalars may be further extracted from these results, assuming the weak breakdown of the de Sitter isometries. These findings offer a step towards a more methodical comprehension of de Sitter observables utilising Mellin space techniques at the tree level and beyond.

    ↳ hep-thgr-qchep-ph3 citations
25. 25*

    Bimetric MOND as a framework for variable-$G$ theories -- local systems and cosmology

    Mordehai Milgrom🇮🇱

    Bimetric MOND (BIMOND) is used as a platform for variable-$G$ theories that have MOND-specific idiosyncrasies. E.g., MOND premises dictate return to standard dynamics in the high-acceleration limit, predicting the standard value of $G$ for high-acceleration systems. This automatically ensures compliance of such theories with all the constraints on inconstancy of $G$ that emerge from the study of high-acceleration systems: geophysics, solar system, pulsars, supernovae, stellar evolution, emission of gravitational waves, etc. In MOND, constraints deduced from such phenomena have no bearing on possible $G$ variability in cosmology. My guiding motivation is to see if such theories may account for some roles of dark matter in cosmology; e.g., in accounting for the expansion history of the Universe in the matter-dominated era, by having a $G_e\approx 2\pi G$ govern the later stages of the expansion, instead of invoking matter density $\approx 2\pi \times$ baryon density. Without adding degrees of freedom, or new dimensionful constants, BIMOND can be extended to a class of theories that entail what is best described as phenomenon-dependence of Newton's constant, $G$. I cannot yet present a consistent model that complies with all the observations in cosmology, including the expansion history, with all its details. Instead, I describe some examples of theories in the class that predict different values of $G_e$ in different circumstances, including one where $G$ takes its standard value for all subcosmological systems -- even if they are deep in the MOND regime. I also discuss scenarios in which $G_e\approx G$ in the early Universe, as required by constraints from big-bang nucleosynthesis, but with $G_e>G$ setting in at later times, where it can affect the expansion history during the matter-dominated era.

    ↳ astro-ph.COastro-ph.GAgr-qchep-phPRD(2026)·0 citations
26. 26*

    Dirac vs. Majorana Dark Matter Imprints on Neutron Star Observables

    M. Bhuyan (IOP BBSR)🇮🇳 · Jeet Amrit Pattnaik (IOP BBSR)🇮🇳 · S. K. Patra (SOA Univ.)🇮🇳 · Sudhanwa Patra (IIT Bhilai and IOP BBSR)🇮🇳

    The fundamental character of a fermionic dark matter, whether it is a Dirac or Majorana particle remains a key unresolved issue whose answer would profoundly affect dark-sector phenomenology and detection strategies thereby motivates complementary probes across particle and astrophysical experiments. Compact stars, particularly neutron stars, offer unique astrophysical laboratories for probing such fundamental properties under extreme densities. The presence of a fermionic DM admixed with nuclear matter can modify the equation of state, thereby affecting observable quantities such as the mass-radius (M-R) relation and tidal deformability. In this work, we investigate how the intrinsic particle nature of fermionic DM influences neutron star structure. Within a relativistic mean-field framework extended by a scalar (or Higgs like) portal coupling between DM and nucleons, we construct self-consistent equation of states for both Dirac and Majorana cases and solve the Tolman-Oppenheimer-Volkoff equations to obtain stellar configurations. Owing to the difference in internal degrees of freedom, Dirac DM (four degrees of freedom) generally softens the equation of state more strongly than Majorana DM (two degrees of freedom), leading to smaller radii and lower maximum masses. We identify the parameter space consistent with current NICER and gravitational-wave constraints, highlighting the potential of compact-star observations to discriminate between Dirac and Majorana dark matter.

    ↳ astro-ph.HEhep-ph0 citations
27. 27*

    3-Dimensional WIMP Effective Velocity Distribution

    Chung-Lin Shan🇹🇼

    In this talk, I discussed a 3-dimensional "effective" velocity distribution of Weakly Interacting Massive Particles (WIMPs), which, instead of the theoretically predicted velocity distribution of "entire" Galactic Dark Matter particles, describes the actual velocity distribution of WIMPs "scattering off" (specified) target nuclei in an underground detector. Based on numerical results carried out by our double Monte Carlo scattering-by-scattering simulation of 3-dimensional elastic WIMP-nucleus scattering, an (asymmetric) "forward-backward asymmetry" was also demonstrated.

    ↳ astro-ph.HEhep-ph0 citations
28. 28*

    Adding electromagnetic birefringence to pulsar timing and astrometry to detect gravitational waves

    Keisuke Inomata🇺🇸 · Marc Kamionkowski🇺🇸

    It was recently shown that the time variation of the polarization of electromagnetic waves from pulsars can be used, in cross-correlation with pulsar timing, to probe the chirality of an isotropic gravitational wave background. Here, we show that the expression for the cross-correlation is derived efficiently with the total-angular-momentum formalism and use this framework to extend the formulation to cross-correlation with astrometry. We do so for spin-1 gravitational waves (that may arise in alternative-gravity theories) as well as the general-relativistic spin-2 gravitational waves.

    ↳ astro-ph.COgr-qchep-phPRD(2026)·0 citations
29. 29*

    Scintillation response of cryogenic CsI to few-keV and sub-keV nuclear recoils

    J.I. Collar🇺🇸 · C.M. Lewis🇺🇸 · A. Simón🇪🇸 · S.G. Yoon🇺🇸

    Monochromatic neutron emissions from photonuclear sources ${}^{88}$Y/Be and ${}^{124}$Sb/Be are employed to obtain the response of pure (undoped) cesium iodide at 80 K. The use of a low-noise, high-quantum-efficiency avalanche photodiode in combination with a novel waveshifter results in a 70 eV analysis threshold. This reach allows to observe signals from sub-keV nuclear recoils originating in neutron scattering. The extracted quenching factor drops much faster towards low energy than the extrapolation of a model developed for room-temperature CsI[Na]. We comment on the impact of our measurement on planned use of cryogenic CsI in neutrino physics and dark matter experiments.

    ↳ physics.ins-dethep-exhep-phnucl-ex2 citations
30. 30*

    Lattice determination of the QCD low-energy constant ${\ell }_7$

    Claudio Bonanno🇪🇸 · Gilberto Colangelo🇨🇭 · Francesco D'Angelo🇮🇹 · Massimo D'Elia🇮🇹 · Roberto Dionisio🇮🇹 · Roberto Frezzotti🇮🇹 · Giuseppe Gagliardi🇮🇹 · Vittorio Lubicz🇮🇹 · Guido Martinelli🇮🇹 · Francesco Sanfilippo🇮🇹 · Silvano Simula🇮🇹

    We provide a non-perturbative determination of the scheme- and scale-independent low-energy constant ${\ell }_7$, appearing in the QCD effective chiral Lagrangian at next-to-leading order, by means of lattice QCD simulations with $N_{\mathrm{f}}=2+1$ quark flavors. We adopt staggered fermions and extract ${\ell }_7$ from the pion mass splitting by suitably generalizing the method introduced in [Phys. Rev. D 104 (2021) 074513] for the Wilson discretization. Adopting 12 gauge ensembles with 3 different values of the pion mass, and 4 different values of the lattice spacing, we are able to achieve controlled extrapolations towards the continuum, infinite volume, and chiral limits. Our final result ${\ell }_7\times 10^3=2.79(58{)}_{\mathrm{stat}}(19{)}_{\mathrm{syst}}=2.79(61{)}_{\mathrm{tot}}$ agrees with and substantially improves on previous determinations.

    ↳ hep-lathep-phhep-thPRD(2026)·2 citations
31. 31*

    Phase transitions at high and low densities for a rotating QCD matter from holography

    Octavio C. Junqueira🇧🇷 · Roldao da Rocha🇧🇷

    We applied the exact Andreev soft-wall holographic model to investigate phase transitions in rotating strongly interacting matter at high and low densities. Using the dual description of hadronic matter and quark-gluon plasma via thermal and charged black holes in five-dimensional AdS space with cylindrical symmetry, we find that for relativistic rotations exceeding 16\% of the speed of light, crossover transitions emerge in the low-density regime up to a critical baryon chemical potential ${\mu }_{CPB}$. These smooth transitions, governed by the negative QCD $\beta$-function, describe a mixed phase of confined and deconfined matter with different angular momenta evolving into a pure plasma at very high temperatures. For $\mu \ge {\mu }_{CPB}$, first-order transitions dominate, following the critical-temperature curve of non-rotating matter. The critical point separating the low-density crossovers from high-density first-order transitions is numerically estimated as $({\mu }_{CPB},T_{CP})=(363.554,58.507)\text{MeV}$.

    ↳ nucl-thhep-phhep-thNPB(2026)·0 citations
32. 32*

    UV Luminosity Functions from HST and JWST: A Possible Resolution to the High-Redshift Galaxy Abundance Puzzle and Implications for Cosmic Strings

    Mattéo Blamart🇨🇦 · Adrian Liu🇨🇦 · Robert Brandenberger🇨🇦 · Julian B. Muñoz🇺🇸 · Bryce Cyr🇺🇸

    Recent observations of high redshift galaxies by the James Webb Space Telescope suggest the presence of a bright population of galaxies that is more abundant than predicted by most galaxy formation models. These observations have led to a rethinking of these models, and numerous astrophysical and cosmological solutions have been proposed, including cosmic strings, topological defects that may be remnants of a specific phase transition in the very early moments of the Universe. In this paper, we integrate cosmic strings, a source of nonlinear and non-Gaussian perturbations, into the semi analytical code Zeus21, allowing us to efficiently predict the ultraviolet luminosity function (UVLF). We conduct a precise study of parameter degeneracies between star-formation astrophysics and cosmic-string phenomenology. Our results suggest that cosmic strings can boost the early-galaxy abundance enough to explain the measured UVLFs from the James Webb and Hubble Space Telescopes from redshift z = 4 to z = 17 without modifying the star-formation physics. In addition, we set a new upper bound on the string tension of $G\mu ⪅10^{-8}$ ($95\%$ credibility), improving upon previous limits from the cosmic microwave background. Although with current data there is some level of model and prior dependence to this limit, it suggests that UVLFs are a promising avenue for future observational constraints on cosmic-string physics.

    ↳ astro-ph.COastro-ph.GAgr-qchep-ph+1PRD(2026)·5 citations
33. 33*

    Dark matter mounds from the collapse of supermassive stars: a general-relativistic analysis

    Roberto Caiozzo🇮🇹 · Gianfranco Bertone🇳🇱 · Piero Ullio🇮🇹 · Rodrigo Vicente🇳🇱 · Bradley J. Kavanagh🇪🇸 · Daniele Gaggero🇮🇹

    Recent work has highlighted the importance of a fully relativistic treatment of the dephasing of gravitational waves induced by dark-matter overdensities in extreme mass-ratio inspirals (EMRIs). However, a general-relativistic description of the dark matter phase-space distribution is currently available only for the case of a dark matter "spike" arising from adiabatic black hole growth. Here we develop a fully general-relativistic formalism for the more realistic scenario in which a supermassive stellar progenitor collapses to a black hole and produces a shallower dark matter overdensity, or "mound". We follow self-consistently the evolution of the supermassive star, its collapse, and the subsequent growth of the resulting black hole, together with the collisionless dark matter orbits. We find that in the regime where the collapse becomes non-adiabatic, the dark matter distribution function is significantly reshaped, with a clear depletion in the low-binding-energy region of phase space. Our results provide a more realistic prediction for the dark matter phase-space distribution around supermassive black holes, which is an essential step in our programme to use future EMRI observations to extract information about both the nature of dark matter and the formation history of the black hole.

    ↳ gr-qcastro-ph.COastro-ph.HEhep-phPRD(2026)·7 citations
34. 34*

    Energy Correlator Conformal Blocks and Positivity

    Bianka Meçaj🇺🇸 · Ian Moult🇺🇸 · Matthew T. Walters🇬🇧 · Yuan Xin🇺🇸

    Correlation functions of energy flow operators (energy-energy correlators) are one of the simplest observables in quantum field theory and gravity, with diverse applications ranging from real world collider physics to constraining the space of consistent theories. In this paper we further develop the conformal block decomposition of energy-energy correlators in conformal field theories (CFTs), focusing on the source-detector operator product expansion (OPE). We compute the general conformal blocks in this channel for traceless symmetric operators of arbitrary spin in the background of a scalar source, considering both parity-even and parity-odd contributions. Motivated by the availability of data from the conformal bootstrap, we analyze the convergence of this source-detector OPE, taking a tensor product of two decoupled CFTs as an elementary example. Finally, we use positivity of energy correlators to derive novel bounds on OPE coefficients involving the stress-energy tensor in generic CFTs, and demonstrate the application of these bounds in the specific example of the 3d Ising CFT, obtaining new constraints for both parity-even and parity-odd operators.

    ↳ hep-thhep-ph7 citations
35. 35*

    ClearPotential: Revealing Local Dark Matter in Three Dimensions

    Eric Putney🇺🇸 · David Shih🇺🇸 · Sung Hak Lim🇰🇷 · Matthew R. Buckley🇺🇸

    We present ClearPotential, a data-driven, three-dimensional measurement of the gravitational potential of the local Milky Way using unsupervised machine learning, without the symmetry assumptions, specific functional forms, and binning required in previous work. The potential is modeled as a neural network, optimized to solve the equilibrium collisionless Boltzmann equation for the observed phase space density of Gaia DR3 Red Clump stars within 4 kpc of the Sun. This density is obtained from data using normalizing flows, and our unsupervised solution to the Boltzmann equation automatically corrects for selection effects from crowding and the dust-driven extinction of starlight. Our fully-differentiable model of the gravitational potential allows us to map the acceleration and mass density of the Galaxy in the volume around the Sun, including in the dust-obscured disk towards the Galactic Center. We determine the dark matter density at the Solar radius to be $(0.84\pm 0.08)\times 10^{-2}{M}_{\odot }/{\mathrm{pc}}^3$, and analyze the structure of the dark matter halo. We find strong evidence for a tilted oblate halo, weak preference for a cored inner profile, and the strongest constraints to date on a possible dark matter disk. We place a bound on the timescale of disequilibrium in the local Milky Way, and find mild evidence for disequilibrium using independent acceleration measurements from timings of binary pulsar systems. This work provides the clearest map of the local Galactic potential to date and marks an important step in the era of data-driven astrometry.

    ↳ astro-ph.GAhep-ph6 citations
36. 36*

    Observational constraints on 3-forms dark energy

    Mariam Bouhmadi-López🇪🇸 · Hsu-Wen Chiang🇨🇳 · Carlos G. Boiza🇪🇸 · Pisin Chen🇹🇼

    3-forms are natural candidates for describing the late-time accelerated expansion of the Universe, as they can inherently reproduce a positive cosmological constant when lacking an evolving potential. When such a potential is present, a 3-form field may exhibit either quintessence-like or phantom-like behaviour. In this paper, we consider a late-time effective dark energy model described by a 3-form with a Gaussian potential, stable during the dark-energy-dominated era. We constrain this model observationally by performing a Markov Chain Monte Carlo (MCMC) analysis employing a comprehensive cosmological dataset, including Planck PR4 cosmic microwave background (CMB) data, DESI DR1 baryon acoustic oscillation (BAO) measurements, Pantheon+ Type Ia supernovae data, low-$z$ Cepheid calibrators, and DES Y1 large-scale structure observations. We demonstrate that the 3-form model successfully increases the predicted Hubble parameter of CMB and BAO data from $67.89\pm 0.36km/s/Mpc$ of $\Lambda$CDM model to $68.29_{-0.61}^{+0.56}km/s/Mpc$ by approaching the potential peak at the right time, thus mildly reducing the tension with the late-time observation. Overall, the 3-form field serves as a promising candidate of phantom-like dark energy from both theoretical and observational points of view.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2026)·6 citations
37. 37*

    Effective Equations of Motion for Massive Higher Spins with Generic Gyromagnetic Ratio

    Karim Benakli🇫🇷

    We construct consistent effective equations of motion for massive charged particles of spin 2 and spin $3/2$ interacting with constant electromagnetic backgrounds. While tree-level unitarity restricts point-like particles to a universal gyromagnetic ratio $g=2$, long-lived composite states such as the ${\Omega }^{-}$ baryon generically deviate from this value. We propose describing such non-minimal couplings without triggering pathologies such as superluminal propagation or the loss of degrees of freedom by treating the system as an Effective Field Theory expanded in powers of the background field strength. By introducing specific operators, we show that algebraic consistency can be restored perturbatively for arbitrary $g$-factors.

    ↳ hep-thhep-phJHEP(2026)·1 citation

* 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.