Thu·Jun 26, 2025Thursday·June 26, 2025

1. 01*

   Neutral and Charged Current Semi-Inclusive Deep-Inelastic Scattering at NNLO QCD

   Leonardo Bonino🇨🇭 · Thomas Gehrmann🇨🇭 · Markus Löchner🇨🇭 · Kay Schönwald🇨🇭 · Giovanni Stagnitto🇮🇹

   Semi-inclusive hadron production in deep inelastic lepton-nucleon scattering (SIDIS) provides important probes of parton distributions and fragmentation functions. We compute the next-to-next-to-leading order (NNLO) massless QCD corrections to the full set of SIDIS coefficient functions in analytical form, accounting for electroweak neutral current and charged current exchange. Focusing on the kinematical setting of SIDIS measurements at the future Electron-Ion Collider (EIC), we quantify the impact of these corrections on the phenomenological predictions and their associated uncertainties. We study the impact of electroweak interference in the neutral current SIDIS process and investigate lepton polarisation asymmetries designed to enhance the sensitivity on charged current SIDIS.

   hep-phJHEP(2025)·25 citations
2. 02*

   Heavy scalar molecule $B_c^{+}{B}_c^{-}$

   S. S. Agaev🇦🇿 · K. Azizi🇮🇷 · H. Sundu🇹🇷

   Mass and full width of the heavy scalar molecule $\mathcal{M}$ composed of the mesons $B_c^{+}$ and $B_c^{-}$ are calculated in the QCD sum rule framework. To find its mass and current coupling, we apply the two-point sum rule method. The width of the hadronic molecule $\mathcal{M}=B_c^{+}{B}_c^{-}$ is evaluated by taking into account its dissociation to ${\eta }_c{\eta }_b,J/\psi {\rm Y}$, and $B_c^{+}{B}_c^{-}$ mesons. Decays into $D$ and $B$ meson pairs with appropriate charges and quantum numbers triggered by $\overline{b}b$ and $\overline{c}c$ annihilations to light quark-antiquarks are also included in the analyses. Because the partial widths of $\mathcal{M}$ molecule's decay channels depend on the strong couplings at $\mathcal{M}$-meson-meson vertices, we estimate them by invoking tools of the three-point sum rule method. Our predictions $m=(12725\pm 85)\mathrm{MeV}$ and $\Gamma [\mathcal{M}]=(155\pm 23)\mathrm{MeV}$ for the parameters of the molecule $\mathcal{M}$ provide useful information for experimental studies of numerous heavy resonances.

   hep-phhep-exhep-latPRD(2025)·7 citations
3. 03*

   Higher-Order Corrections to Quantum Observables in $h\to W{W}^{\ast }$

   Dorival Gonçalves🇺🇸 · Ajay Kaladharan🇺🇸 · Alberto Navarro🇺🇸

   The Higgs boson decay $h\to W{W}^{\ast }\to {\ell }^{+}{\nu }_{\ell }{\ell }^{\prime -}{\bar{\nu }}_{{\ell }^{\prime }}$ provides a unique window into the structure of the Higgs couplings to electroweak gauge bosons and has recently gained attention for its potential to unveil quantum properties such as quantum entanglement between the intermediate gauge bosons. In this work, we present a systematic study of next-to-leading order electroweak corrections to the angular coefficients characterizing this decay. While these coefficients are highly constrained at leading order, radiative corrections induce shifts of up to 5% to the existing terms and generate novel structures that vanish at leading order, breaking previous relations among coefficients. While higher-order effects influence the results, the two-qutrit quantum structure in the $h\to W{W}^{\ast }$ channel exhibits greater stability under such corrections than in the previously studied $h\to Z{Z}^{\ast }$ decay.

   hep-phhep-exquant-phJHEP(2025)·35 citations
4. 04*

   WIMP/FIMP dark matter and primordial black holes with memory burden effect

   Teruyuki Kitabayashi🇯🇵 · Amane Takeshita🇯🇵

   The lifetime of primordial black holes (PBHs), which formed in the early universe, can be extended by the memory burden effect. Light PBHs may exist today and be candidates for dark matter (DM). We assume that DM is made of thermally produced weakly interacting massive particles (WIMPs), WIMPs produced via the Hawking radiation of PBHs, and PBHs that survived Hawking evaporation via the memory burden effect. Feebly interacting massive particles (FIMPs) are alternatives to WIMPs. Focusing on parameter regions where thermal production dominates and PBHs never dominate the energy density of the Universe, we identify a sufficient condition under which DM particles emitted from PBHs do not thermalize with the thermal bath. In this regime, the total DM relic abundance can be consistently obtained as the sum of the three components. In addition, we show that the contribution from gravitational freeze-in via graviton exchange remains subdominant within the parameter space considered.

   hep-phastro-ph.COInt.J.Mod.Phys.A(2026)·8 citations
5. 05*

   Constraints on the dark sector from electroweak precision observables

   B. M. Loizos🇦🇺 · X. G. Wang🇦🇺 · A. W. Thomas🇦🇺 · M. J. White · A. G. Williams🇦🇺

   We revisit the Standard Model fit to electroweak precision observables in using the latest data and the Particle Data Group (PDG) measurement of the W boson mass. The analysis is then repeated in light of the new W boson mass measurement from the Collider Detector at Fermilab (CDF) collaboration. We then introduce a dark photon to the model, placing constraints on the parameter space arising from these electroweak precision observables, both for the PDG and CDF values for the W boson mass. We also extend previous work by placing the first electroweak precision observable constraints on the coupling of dark photons to the fermionic dark matter sector.

   hep-phhep-ex0 citations
6. 06*

   Mono-Higgs signature in a singlet fermionic dark matter model

   Yeong Gyun Kim🇰🇷 · Kang Young Lee🇰🇷 · Soo-hyeon Nam🇰🇷

   We investigate mono-Higgs production as a probe of singlet fermionic dark matter (SFDM) at the LHC. In this framework, a Standard Model (SM) gauge-singlet Dirac fermion serves as the dark matter candidate, interacting with the visible sector through a real scalar mediator that mixes with the SM Higgs boson. Focusing on the light dark matter regime with masses at or below the GeV scale, we analyze the viable parameter space under constraints from relic density, Higgs decay properties, invisible decay bounds, rare $B$-meson decays, and direct detection experiments. We compute the mono-Higgs production cross sections at $\sqrt{s}=13\mathrm{TeV}$ and compare the predicted event yields with current ATLAS and CMS results. We find that the dominant contribution arises from di-Higgs production followed by the invisible decay of one Higgs boson, with the rate largely controlled by the scalar trilinear coupling. For representative benchmark points consistent with all current constraints, the predicted signal remains below existing experimental limits. Despite the current non-observation, the mono-Higgs channel provides a complementary probe of Higgs-portal dark matter scenarios, particularly in the low-mass mediator regime. Our results indicate that future high-luminosity LHC data may enable significant exploration of the viable SFDM parameter space.

   hep-phhep-ex1 citation
7. 07*

   Investigation of $T_{cs0}^{\ast }(2870{)}^0$ in $pp$ collisions at $\sqrt{s}$ = 7 TeV with the PACIAE model

   Qiang Wang🇨🇳 · Zhi-Lei She🇨🇳 · An-Ke Lei🇨🇳 · Dai-Mei Zhou🇨🇳 · Wen-Chao Zhang🇨🇳 · Hua Zheng🇨🇳 · Yu-Liang Yan🇨🇳 · Ben-Hao Sa🇨🇳

   We have used the parton and hadron cascade model PACIAE together with the Dynamically Constrained Phase-space Coalescence model (DCPC) to study the $T_{cs0}^{\ast }(2870{)}^0$ production in $pp$ collision at $\sqrt{s}$ = 7 TeV, following the LHCb observation of $T_{cs0}^{\ast }(2870{)}^0$ in the $B^{-}\to D^{-}{D}^0{K}_S^0$ decays in $pp$ collisions at $\sqrt{s}$ = 7, 8, and 13 TeV [PRL 134(2025)101901]. The final hadronic states of the $pp$ collisions at $\sqrt{s}$ = 7 TeV are first simulated by the PACIAE model. Four sets of $T_{cs0}^{\ast }(2870{)}^0$ candidates are then recombined by the DCPC model using the constituent meson pair of $D^0{K}_S^0$, $D^{+}{K}^{-}$, $D^{\ast +}{K}^{\ast -}$, and $D^{\ast 0}{\bar{K}}^{\ast 0}$ based on the above simulated final hadronic states, respectively. We calculate their rapidity distributions, transverse momentum spectra, and angular distribution between the two component mesons, as well as angular distribution between $D$ component meson and $T_{cs0}^{\ast }(2870{)}^0$. Our results show that the yields of four $T_{cs0}^{\ast }(2870{)}^0$ candidates follow the magnitude order of $D^0{K}_S^0$ $>$ $D^{+}{K}^{-}$ $>$ $D^{\ast +}{K}^{\ast -}$ $\sim$ $D^{\ast 0}{\bar{K}}^{\ast 0}$. Similar ordering behavior is also observed in the aforementioned distributions.

   hep-phPLB(2026)·2 citations
8. 08*

   Unraveling dark Higgs mechanism via dark photon production at an e^+ e^- collider

   Song Li🇨🇳 · Jin Min Yang🇨🇳 · Mengchao Zhang🇨🇳 · Yang Zhang🇨🇳 · Rui Zhu🇨🇳

   In the phenomenology study of dark photon, its mass origin is usually not under concern. However, in theory construction its mass is often generated via a dark Higgs mechanism, which leads to the presence of a light (non-decoupled) dark Higgs particle. In this work, we study the impact of such a dark Higgs particle in the collider detection of the dark photon. We focus on the process of final state dark photon radiating dark Higgs, which is called dark final state radiation (FSR). Considering the effects on both the signal cross section and the distribution of the missing mass square, the invisible dark photon search at BaBar is reanalyzed and a new exclusion limit for invisible dark photon is presented.

   hep-phJHEP(2026)·7 citations
9. 09*

   Functional renormalization group study of anomalous magnetic moment in a low energy effective theory

   Rui Wen🇨🇳 · Chuang Huang🇩🇪 · Mei Huang🇨🇳

   The quark anomalous magnetic moments (AMMs) are investigated in a 2-flavor low-energy effective theory within the functional renormalization group (FRG) approach under an external magnetic field. The Schwinger formalism is adopted for quark propagators, and Fierz-complete four-quark scatterings are self-consistently included through the renormalization group flows. We find that the quark AMMs are dynamically generated with the chiral symmetry breaking, and the magnitude of the AMM of the down quark is around 4 times larger than that of the up quark. The transverse AMMs and the longitudinal d-quark AMM monotonically decrease with the magnetic field strength, while the longitudinal u-quark AMM slightly increases with the magnetic field strength. At $B=0$, the magnetic moments of proton and neutron are computed using the constituent quark model, which are close to the experimental values.

   hep-phPRD(2026)·3 citations
10. 10*

    Investigating New Physics through the Observables of Semileptonic $B_s\to K^{\ast }(\to K\pi ){\mu }^{+}{\mu }^{-}$ Decay

    Zohaib Aarfi🇵🇰 · Qazi Maaz Us Salam🇵🇰 · Ishtiaq Ahmed🇵🇰 · Faisal Munir Bhutta🇵🇰 · Rizwan Khalid🇵🇰 · M.Ali Paracha🇵🇰

    The rare four-fold decay $B_s\to K^{\ast }(\to K\pi ){\mu }^{+}{\mu }^{-}$, governed by the flavor-changing neutral current transition $b\to d{\mu }^{+}{\mu }^{-}$, provides a sensitive probe for testing the Standard Model (SM) and investigating signatures of new physics (NP). This work presents a comprehensive model-independent analysis of the decay using the framework of the weak effective field theory. We compute a set of key physical observables, including the differential branching ratio, forward-backward asymmetry, longitudinal polarization fraction, and several normalized angular coefficients $⟨I_i⟩$, as a function of the dilepton invariant mass squared $q^2$. The impact of NP is explored via both one-dimensional (1D) and two-dimensional (2D) scenarios involving NP Wilson coefficients $C_7^{\text{NP}}$, $C_9^{(\prime )\text{NP}}$, and $C_{10}^{(\prime )\text{NP}}$. Our findings reveal notable deviations from the SM predictions across multiple observables. Furthermore, we analyze the correlations between different observables and their 2D contour plots which would be useful to further constrain the parametric space of possible NP contributions. This study reinforces the potential of $B_s\to K^{\ast }{\mu }^{+}{\mu }^{-}$ decay as a complementary channel in the search for physics beyond the SM.

    hep-phPTEP·6 citations
11. 11*

    DeepQuark: A Deep-Neural-Network Approach to Multiquark Bound States

    Wei-Lin Wu🇨🇳 · Lu Meng🇩🇪 · Shi-Lin Zhu🇨🇳

    For the first time, we implement the deep-neural-network-based variational Monte Carlo approach for the multiquark bound states, whose complexity surpasses that of electron or nucleon systems due to strong SU(3) color interactions. We design a novel and high-efficiency architecture, DeepQuark, to address the unique challenges in multiquark systems such as stronger correlations, extra discrete quantum numbers, and intractable confinement interaction. Our method demonstrates competitive performance with state-of-the-art approaches, including diffusion Monte Carlo and Gaussian expansion method, in the nucleon, doubly heavy tetraquark, and fully heavy tetraquark systems. Notably, it outperforms existing calculations for pentaquarks, exemplified by the triply heavy pentaquark. For the nucleon, we successfully incorporate three-body flux-tube confinement interactions without additional computational costs. In tetraquark systems, we consistently describe hadronic molecule $T_{cc}$ and compact tetraquark $T_{bb}$ with an unbiased form of wave function ansatz. In the pentaquark sector, we obtain weakly bound ${\bar{D}}^{\ast }{\Xi }_{cc}^{\ast }$ molecule $P_{cc\bar{c}}(5715)$ with $S=\frac{5}{2}$ and its bottom partner $P_{bb\bar{b}}(15569)$. They can be viewed as the analogs of the molecular $T_{cc}$. We recommend experimental search of $P_{cc\bar{c}}(5715)$ in the D-wave $J/\psi {\Lambda }_c$ channel. DeepQuark holds great promise for extension to larger multiquark systems, overcoming the computational barriers in conventional methods. It also serves as a powerful framework for exploring confining mechanism beyond two-body interactions in multiquark states, which may offer valuable insights into nonperturbative QCD and general many-body physics.

    hep-phcs.AIhep-exhep-lat+1PRL(2026)·15 citations
12. 12*

    Analytic formulation of Leptogenesis with neutrino oscillation data employing the general parametrization for neutrino mass matrix

    Nobuchika Okada🇺🇸 · Digesh Raut🇺🇸

    The observed neutrino oscillations and baryon asymmetry, unexplained by the Standard Model (SM), can both be accounted for by extending the SM to include Majorana right-handed neutrinos (RHNs). Tiny neutrino masses naturally arise through the Type-I seesaw mechanism, which involves lepton number violation. Meanwhile, the baryon asymmetry can be generated via leptogenesis, where the out-of-equilibrium decay of RHNs produces a lepton asymmetry that is partially converted into a baryon asymmetry through sphaleron processes. The Dirac Yukawa couplings play the crucial role for both Type-I seesaw and leptogenesis. In this work, we derive an analytic expression for the CP asymmetry parameter in a general parametrization. Focusing on a hierarchical RHN mass spectrum, we evaluate the lowest mass of the lightest RHN that reproduce both neutrino oscillation data and the observed baryon asymmetry. We study the case with two and three generations of RHNs for both thermal and non-thermal leptogenesis scenarios. Besides the standard Type-I seesaw involving SM Higgs doublet, we also examine the Type-I seesaw with a new neutrinophillic Higgs doublet. In this case for non-thermal leptogenesis, the minimum value for the lightest RHN mass can be as low as sphaleron decoupling temperature.

    hep-phhep-th4 citations
13. 13*

    Extracting the kinetic freeze-out properties of high energy pp collisions at the LHC with event shape classifiers

    Jialin He🇨🇳 · Xinye Peng🇨🇳 · Zhongbao Yin🇨🇳 · Liang Zheng🇨🇳

    Event shape measurements are crucial for understanding the underlying event and multiple-parton interactions (MPIs) in high energy proton-proton (pp) collisions. In this paper, the Tsallis Blast-Wave model with independent non-extensive parameters for mesons and baryons, was applied to analyze transverse momentum spectra of charged pions, kaons, and protons in pp collision events at $\sqrt{s}=13$ TeV classified by event shape estimators relative transverse event activity, unweighted transverse spherocity, and flattenicity. Our analysis reveals consistent trends in the kinetic freeze-out temperature and non-extensive parameter across different collision systems and event shape classes. The use of diverse event-shape observables in pp collisions has significantly expanded the accessible freeze-out parameter space, allowing for a more comprehensive exploration of its boundaries. Among these event shape classifiers, flattenicity emerges as a unique observable for disentangling hard process contributions from additive MPI effects, allowing the isolation of collective motion effects encoded by the radial flow velocity. Through the analysis of the interplay between event-shape measurements and kinetic freeze-out properties, we gain deeper insights into the mechanisms responsible for flow-like signatures in pp collisions.

    hep-phnucl-exCPC(2026)·1 citation
14. 14*

    A Flavor of SO(10) Unification with a Spinor Higgs

    Juanca Carrasco-Martinez🇺🇸 · Lawrence J. Hall🇺🇸 · Keisuke Harigaya🇺🇸 · Kevin Langhoff🇺🇸

    We investigate Higgs Parity Unification-a realization of $SO(10)$ grand unification based on the Higgs Parity mechanism in which the Standard Model (SM) Higgs resides in a spinor representation. The theory has an intermediate left-right symmetric stage where the $SU(2{)}_R$ symmetry breaking scale is fixed by the vanishing of the SM Higgs quartic coupling. The strong $CP$ problem is solved by parity. Gauge coupling unification successfully predicts ${\alpha }_s(M_Z)$ to within 1%. The spinor Higgs naturally leads to a seesaw origin for SM flavor observables. We identify a novel mechanism where large mixing of third generation fermions with additional heavy vector-like fermions accounts for the anarchical nature of the PMNS matrix and the lack of hierarchy in the neutrino mass spectrum, relative to the up-quarks. A fit to quark and lepton masses and mixings, with a minimal parameter set, predicts 1) A testable relation between the top quark mass and ${\alpha }_s(M_Z)$ which is about $(1-2)\sigma$ from current best fit values, 2) The order of magnitude of the baryon asymmetry of the universe, via leptogenesis from second-generation right-handed neutrino decays. 3) The proton decay and the neutron EDM are likely observable in next generation experiments, and 4) A normal ordered neutrino mass spectrum where $0\nu \beta \beta$ decay and the mass of the lightest neutrino are out of reach of next generation experiments.

    hep-phJHEP(2025)·6 citations
15. 15*

    Interpreting the 95 GeV resonance in the Two Higgs Doublet Model: Implications for the Electroweak Phase Transition

    Ansh Bhatnagar🇬🇧 · Djuna Croon🇬🇧 · Philipp Schicho🇨🇭

    We investigate if the recent mass resonance excesses seen around 95 GeV at the Large Hadron Collider (LHC) can be reconciled with a first-order electroweak phase transition. Performing the first large-scale parameter scan of the Type I Two Higgs Doublet Model (2HDM) using high-temperature dimensionally reduced effective field theory, we focus on regions of parameter space consistent with interpreting the excess as an additional pseudoscalar state. We find that, in contrast to the Standard Model, the electroweak transition pattern in the 2HDM is generically first-order, proceeding either in a single or in two steps. While transition strengths can reach up to $v_c/T_C\sim 1.3$, the viable, collider-constrained parameter space yields $v_c/T_C\lesssim 1$. Thus, the gravitational wave signals lie below the projected reach of future interferometer experiments and are likely insufficient to support successful electroweak baryogenesis.

    hep-phastro-ph.COJHEP(2026)·18 citations
16. 16*

    Fermionic S-matrix and cosmological correlators: T-violation at O(H)

    Aman Goyal🇮🇳 · Aneek Jana🇮🇳 · Swapnanil Mandal🇮🇳 · Aninda Sinha🇮🇳

    We study the Bunch-Davies (BD) and Unruh-de Witt (UdW) de Sitter S-matrices in the presence of spin-$1/2$ fermions. Building on recent work, this enables us to correlate the de Sitter S-matrix with cosmological correlators. We consider a finite-time version of the UdW S-matrix to study $O(H)$ corrections to some typical particle physics processes such as beta decay. Owing to the lack of time-reversal symmetry in the expanding Poincaré patch, we find signatures of intrinsic T-violation in polarized beta decay. The observable we study begins at $O(H)$. The possibility of T-violation was examined theoretically in the 1950's by Jackson, Treiman, and Wyld in flat space and has been probed more recently in the emiT experiment, with the purpose of examining fundamental T-violation coming from additional interactions in the Lagrangian. Our analysis places a lower bound on the intrinsic T-violation in the expanding Poincaré patch. At $O(H)$, we find both energy conserving and energy non-conserving contributions. Surprisingly, the energy-violating piece, in principle, can give large T-violation at fine-tuned values of the kinematical variables.

    ↳ hep-thgr-qchep-phJCAP(2025)·4 citations
17. 17*

    New bounds on Axion-Like Particles in the Ultraviolet from Legacy Data

    Elisa Todarello🇬🇧

    We use legacy data from the Hubble Space Telescope (HST) and the International Ultraviolet Explorer (IUE) to search for a spectral line from the spontaneous decay of axion-like particle (ALP) dark matter. The HST data consist of blank sky observations taken with the Faint Object Spectrograph in the 165--240~nm wavelength range, while the IUE data consist of observations of the Virgo Cluster obtained with the long- and short-wavelength spectrographs, covering 195--325~nm and 123--200~nm, respectively. We set a 95\% C.L. upper limit on the ALP--photon coupling $g_{a\gamma }\lesssim 10^{-11}{\mathrm{GeV}}^{-1}$ across the whole probed ALP mass range. Notably, we rule out values of $g_{a\gamma }$ above $2.3\times 10^{-12}{\mathrm{GeV}}^{-1}$ for ALP masses between 12.4 and 14.5\,eV, improving upon previous limits by a factor of seven.

    ↳ astro-ph.COhep-phJCAP(2026)·2 citations
18. 18*

    Unlocking Multidimensional Integration with Quantum Adaptive Importance Sampling

    Konstantinos Pyretzidis🇪🇸 · Jorge J. Martínez de Lejarza🇪🇸 · Germán Rodrigo🇪🇸

    Multidimensional numerical integration is a central ingredient of theoretical predictions in high-energy physics, where multiloop Feynman diagrams and phase-space integrals are computationally demanding due to divergences and complex mathematical structures. Established Adaptive Importance Sampling methods for numerical integration, such as VEGAS, iteratively refine a grid in a separable way, dimension by dimension. This keeps the algorithm scalable but reduces performance when strong inter-variable correlations are present. In this work, we introduce a hybrid quantum-classical algorithm that performs Quantum Adaptive Importance Sampling (QAIS) for multidimensional Monte Carlo integration. Our approach uses a Parametrized Quantum Circuit to encode a non-separable Probability Density Function on a multidimensional grid and allocate samples efficiently in the integration domain. We apply the method to a sharply peaked loop Feynman integral and to multi-modal benchmark integrals. Our results show that QAIS provides an efficient route for high-precision evaluation of multidimensional integrals.

    ↳ quant-phhep-phCommun.Phys.(2026)·11 citations
19. 19*

    Microquasar jet-cocoon systems as PeVatrons

    B. Theodore Zhang🇨🇳 · Shigeo S. Kimura🇯🇵 · Kohta Murase🇺🇸

    The origin of Galactic cosmic rays (CRs), particularly around the knee region ($\sim$3 PeV), remains a major unsolved question. Recent observations by LHAAASO suggest that the knee is shaped mainly by protons, with a transition to heavier elements at higher energies. Microquasars -- compact jet-emitting sources -- have emerged as possible PeV CR accelerators, especially after detections of ultrahigh-energy gamma rays from these systems. We propose that the observed proton spectrum (hard below a few PeV, steep beyond) arises from the reacceleration of sub-TeV Galactic CRs via shear acceleration in large-scale microquasar jet-cocoon structures. Our model also naturally explains the observed spectrum of energies around a few tens of PeV by summing up heavier nuclei contributions. Additionally, similar reacceleration processes in radio galaxies can contribute to ultrahigh-energy CRs, bridging Galactic and extragalactic origins. Combined with low-energy CRs from supernova remnants and galaxy clusters around the second knee region, this scenario could provide a unified explanation for CRs across the entire energy spectrum.

    ↳ astro-ph.HEhep-exhep-phPRD(2025)·22 citations
20. 20*

    Linear and nonlinear supersymmetry in field and string theory

    Gabriele Casagrande🇫🇷

    This Ph.D. thesis investigates effective field and string theories in which supersymmetry is realized and broken in various ways. Chapter 1 addresses effective theories with nonlinearly realized supersymmetry, constructed using the formalism of constrained superfields. We establish a criterion for identifying inconsistent constraints, formulate their improved versions, and propose, along these lines, improved supergravity models of inflation. In Chapter 2, we discuss a peculiar application of this framework: the gravitational production of massive gravitinos in time-dependent backgrounds. We emphasize some physical subtleties in the standard description of this mechanism, which become particularly severe in the case of the gravitino. Next, the focus shifts to linear supersymmetry, and we investigate the leading-order coupling of the massive spin-2 field supermultiplet to pure supergravity in four dimensions. This analysis is carried out using the supercurrent superfield formalism, and it shows that only a single class of such couplings can be consistently defined. This is fundamentally distinct from the coupling obtained by compactifying higher-dimensional supergravities, and it has interesting connections to string theory and the string lamppost principle. Finally, in Chapter 3, we present a novel orientifold projection of type IIB string theory. This is a Scherk--Schwarz orientifold in which supersymmetry is entirely broken, and the O-planes couple only to the twisted sector of the theory. We argue that this model is invariant under S-duality and can be formulated as an F-theory compactification. We also analyze the D-brane spectrum of the theory and compare the results with earlier similar constructions. All original findings presented in this thesis are preceded by a comprehensive and detailed introduction to the general frameworks to which they belong.

    ↳ hep-thhep-ph1 citation
21. 21*

    Schwinger effect in axion inflation on a lattice

    Oksana Iarygina🇸🇪 · Evangelos I. Sfakianakis🇺🇸 · Axel Brandenburg🇸🇪

    We present the first lattice simulations of the nonlinear evolution after axion inflation by self-consistently incorporating currents arising from Schwinger pair production. The tachyonically amplified gauge fields trigger the growth of Schwinger currents, leading to universal values for the conductivity and magnetic field at the onset of strong backreaction and subsequent quenching of gauge field production. We show that the Schwinger effect (prematurely) saturates gauge field production, thereby diminishing the prospects of high scale axion inflation magnetogenesis as a viable solution for blazar observations.

    ↳ astro-ph.COhep-phhep-th17 citations
22. 22*

    Cosmological bounds on dark matter annihilation using dark ages 21-cm signal

    Vivekanand Mohapatra🇮🇳

    We investigate the impact of dark matter (DM) annihilation on the global 21-cm signal during the dark ages and cosmic dawn eras. The 21-cm line provides a complementary probe for studying the nature of dark matter beyond standard cosmological observables. In the standard $\Lambda$CDM framework, the expected absorption amplitude of the dark ages global 21-cm signal is approximately $-42\mathrm{mK}$. However, energy injection from DM annihilation can significantly heat and ionize the intergalactic medium, potentially altering or even erasing this absorption feature. We evaluate the thermal and ionization history of the gas to derive an upper bound on $f_{\chi }^2⟨\sigma v⟩/M_{\chi }$ using the dark ages signal, which is free from astrophysical uncertainties. After incorporating observational and theoretical uncertainties arising from future lunar-based experiments and variations in cosmological parameters, respectively -- we obtain a conservative upper limit of $f_{\chi }^2⟨\sigma v⟩/M_{\chi }\lesssim 10^{-27}\mathrm{c}{\mathrm{m}}^3{\mathrm{s}}^{-1}\mathrm{Ge}{\mathrm{V}}^{-1}$. This constraint is stronger than the bounds derived from Planck (2018) data for mass $\lesssim 10\mathrm{GeV}$.

    ↳ astro-ph.COhep-phPhys.Dark Univ.(2025)·3 citations
23. 23*

    Relativistic spin hydrodynamics with antisymmetric spin tensors and an extension of the Bargmann-Michel-Telegdi equation

    Shuo Fang🇨🇳 · Kenji Fukushima🇯🇵 · Shi Pu🇨🇳 · Dong-Lin Wang🇨🇳

    We derive a formulation of relativistic spin hydrodynamics with totally antisymmetric spin tensors that satisfy the Frenkel-Mathisson-Pirani condition. In our proposed spin hydrodynamics, the second law of thermodynamics is fulfilled by the spin-induced corrections in the heat flow, the viscous tensor, and the antisymmetric part of the energy-momentum tensor. These corrections are interpreted as the inverse spin Hall effect and the anomalous Hall effect in the nonrelativistic limit. We show that our evolution equation for the spin density is interpreted as an extension of the Bargmann-Michel-Telegdi equation known in relativistic many-body systems, including the Thomas precession term, the spin-rotation term, and new coupling terms between spin and hydrodynamic variables.

    ↳ nucl-thhep-phhep-thPRL(2026)·13 citations
24. 24*

    Updated constraints on the primordial power spectrum at sub-Mpc scales

    Torsten Bringmann🇳🇴 · Djuna Croon🇬🇧 · Sergio Sevillano Muñoz🇬🇧

    The primordial power spectrum of matter density perturbations contains highly valuable information about new fundamental physics, in particular cosmological inflation, but is only very weakly constrained observationally for small cosmological scales $k\gtrsim 3{\mathrm{Mpc}}^{-1}$. We derive novel constraints, ${\mathcal{P}}_{\mathcal{R}}(k)\lesssim 5\cdot 10^{-6}$ over a large range of such scales, from the formation of ultracompact minihalos in the early universe. Unlike most existing constraints of this type, our results do not rest on the assumption that dark matter can annihilate into ordinary matter.

    ↳ astro-ph.COhep-phPRL(2026)·17 citations
25. 25*

    Dark Classification Matters: Searching for Primordial Black Holes with LSST

    Miguel Crispim Romao🇬🇧 · Djuna Croon🇬🇧 · Benedict Crossey🇬🇧 · Daniel Godines🇺🇸

    We present projected constraints on the abundance of primordial black holes (PBHs) as a constituent of dark matter, based on microlensing observations from the upcoming Legacy Survey of Space and Time (LSST) at the Vera C. Rubin Observatory. We use a catalogue of microlensing light curves simulated with Rubin Observatory's OpSims to demonstrate that competitive constraints crucially rely on minimising the false positive rate (FPR) of the classification algorithm. We propose the Bayesian information criterion and a Boosted Decision Tree as effective discriminators and compare their derived efficiency and FPR to a more standard ${\chi }^2$-test.

    ↳ astro-ph.COastro-ph.IMastro-ph.SRgr-qc+1JCAP(2025)·4 citations
26. 26*

    Hybrid thermalization in the large $N$ limit

    Toshali Mitra🇩🇪 · Sukrut Mondkar🇮🇳 · Ayan Mukhopadhyay🇨🇱 · Alexander Soloviev🇸🇮

    Semi-holography provides a formulation of dynamics in gauge theories involving both weakly self-interacting (perturbative) and strongly self-interacting (non-perturbative) degrees of freedom. These two subsectors interact via their effective metrics and sources, while the full local energy-momentum tensor is conserved in the physical background metric. In the large $N$ limit, the subsectors have their individual entropy currents, and so the full system can reach a pseudo-equilibrium state in which each subsector has a different physical temperature. We first complete the proof that the global thermal equilibrium state, where both subsectors have the \textit{same} physical temperature, can be defined in consistency with the principles of thermodynamics and statistical mechanics. Particularly, we show that the global equilibrium state is the unique state with maximum entropy in the microcanonical ensemble. Furthermore, we show that in the large $N$ limit, a \textit{typical} non-equilibrium state of the full isolated system relaxes to the global equilibrium state when the average energy density is large compared to the scale set by the inter-system coupling. We discuss quantum statistical perspectives.

    ↳ hep-thcond-mat.stat-mechhep-phJHEP(2026)·1 citation
27. 27*

    New bounds on Memory Burdened Primordial Black Holes from Big Bang Nucleosynthesis

    Arnab Chaudhuri🇯🇵 · Kazunori Kohri🇯🇵 · Valentin Thoss🇩🇪

    Primordial black holes (PBHs) with masses below $10^9\mathrm{g}$ are typically assumed to have negligible cosmological impact due to their rapid evaporation via Hawking radiation. However, the 'memory burden' effect, which is a quantum suppression of PBH evaporation, can dramatically alter their decay dynamics. In this work, we revisit early-Universe constraints on ultralight PBHs in this mass range, demonstrating that memory burden significantly alters previous constraints. We compute new cosmological bounds from BBN that strongly limit the presence of ultralight PBHs in the early Universe. We report that the PBHs in the mass range $10^0$-$10^2\mathrm{g}$ for $k=2$ are unconstrained by observations.

    ↳ astro-ph.COhep-phJCAP(2025)·18 citations
28. 28*

    Diagnosing electron-neutrino lepton number crossings in core-collapse supernovae: A comparison of methods

    Marie Cornelius (NBIA and DARK, Niels Bohr Institute)🇩🇰 · Irene Tamborra (NBIA and DARK, Niels Bohr Institute)🇩🇰 · Malte Heinlein (MPI Astrophysics, Garching and TUM, Garching)🇩🇪 · Hans-Thomas Janka (MPI Astrophysics, Garching)🇩🇪

    Fast neutrino flavor conversion may impact the explosion mechanism and nucleosynthesis in core-collapse supernovae. A necessary condition for fast flavor conversion is the presence of crossings in the angular distribution of the electron-neutrino lepton number (ELN) crossing. Because of the computational costs, flavor-dependent angular distributions are not computed by the vast majority of state-of-the-art hydrodynamical simulations; instead, angular distributions are reconstructed employing approximate methods in post-processing. In this work, we evaluate the performance of four methods adopted to diagnose the existence of ELN crossings. For selected post-bounce times, we extract the fluid and thermodynamic properties from spherically symmetric supernova simulations for an $18.6M_{\odot }$ progenitor, testing cases with and without muons as well as with and without mixing-length treatment of proto-neutron star convection. We compare the occurrence of crossings in the angular distributions obtained by solving the Boltzmann equations with those in distributions reconstructed from angular moments of our Boltzmann solutions by using the maximum entropy and Minerbo schemes, and also with crossings identified via a polynomial weighting function applied to the angular moments. Our results show that the polynomial method and the Minerbo closure scheme have severe limitations. The maximum entropy approach captures most of the forward crossings, although it fails to reproduce or misidentifies crossings in a subset of our models. These findings highlight the need for robust modeling of the neutrino angular properties in order to assess the impact of flavor conversion on the supernova mechanism.

    ↳ astro-ph.HEhep-phPRD(2025)·12 citations
29. 29*

    Test-time Scaling Techniques in Theoretical Physics -- A Comparison of Methods on the TPBench Dataset

    Zhiqi Gao🇺🇸 · Tianyi Li🇨🇳 · Yurii Kvasiuk🇺🇸 · Sai Chaitanya Tadepalli🇺🇸 · Maja Rudolph🇸🇬 · Daniel J.H. Chung🇺🇸 · Frederic Sala🇺🇸 · Moritz Münchmeyer🇺🇸

    Large language models (LLMs) have shown strong capabilities in complex reasoning, and test-time scaling techniques can enhance their performance with comparably low cost. Many of these methods have been developed and evaluated on mathematical reasoning benchmarks such as AIME. This paper investigates whether the lessons learned from these benchmarks generalize to the domain of advanced theoretical physics. We evaluate a range of common test-time scaling methods on the TPBench physics dataset and compare their effectiveness with results on AIME. To better leverage the structure of physics problems, we develop a novel, symbolic weak-verifier framework to improve parallel scaling results. Our empirical results demonstrate that this method significantly outperforms existing test-time scaling approaches on TPBench. We also evaluate our method on AIME, confirming its effectiveness in solving advanced mathematical problems. Our findings highlight the power of step-wise symbolic verification for tackling complex scientific problems.

    ↳ cs.LGastro-ph.COcs.AIhep-ph+14 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.