Mon·May 5, 2025Monday·May 5, 2025

1. 01*

   Study of electron-positron annihilation into four pions within chiral effective field theory in the low energy region

   Jia-Yu Zhou🇨🇳 · Hao-Xiang Pan🇨🇳 · Ling-Yun Dai🇨🇳

   In this paper, we employ chiral effective field theory to study the process of electron-positron annihilation into four pions in the low energy region within $E_{c.m.}\le 0.6$ GeV. The prediction of the cross section is obtained through $SU(3)$ chiral perturbation theory up to the next-to-leading order, which is smaller than the experimental data in the energy region [0.6-0.65] GeV, though the data has only a few points and poor statistics. Then, the resonance chiral theory is applied to include the resonance contribution, with the lightest scalars and vectors written in the effective Lagrangians. A series of relevant decay widths and the masses of the vectors are studied to fix the unknown couplings. The resonance contribution should be one order larger than that of the chiral perturbation theory but still one to two orders smaller than the data. The significant discrepancy urged the new experimental measurements to give more guidance. We also compute the leading order hadronic vacuum polarization contribution from the four pion channels to the anomalous magnetic moment of the muon, $(g-2{)}_{\mu }$. In the energy range from threshold up to 0.6 GeV within resonance chiral theory, the contributions are $a_{\mu }=(0.680\pm 0.062)\times 10^{-16}$ and $a_{\mu }=(0.597\pm 0.058)\times 10^{-16}$ for the processes of $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{+}{\pi }^{-}{\pi }^{-}$, ${\pi }^0{\pi }^0{\pi }^{+}{\pi }^{-}$, respectively.

   hep-phnucl-thPRD(2026)·2 citations
2. 02*

   Detecting gravitational signatures of dark matter with atom gradiometers

   Leonardo Badurina🇺🇸 · Yufeng Du🇺🇸 · Vincent S. H. Lee🇺🇸 · Yikun Wang🇺🇸 · Kathryn M. Zurek🇺🇸

   We study the purely gravitational signatures of dark matter from the ultralight to the ultraheavy mass range in proposed long-baseline atom gradiometers, focusing on terrestrial designs, such as AION-km and MAGIS-km, as well as space-based concepts, such as MAGIS-space, AEDGE and AEDGE+. Due to its exceptional acceleration sensitivity and depending on astrophysical backgrounds, a detector similar to AEDGE+ could detect a dark matter subcomponent which constitutes $\mathcal{O}(10\%)$ of the local dark matter energy density and is populated by compact clumps of mass between $10^6$~kg and $10^{10}$~kg ($10^{-25}{M}_{\odot }\lesssim M\lesssim 10^{-21}{M}_{\odot }$) in an otherwise unexplored region of dark matter model space. Furthermore, because the gravitational observable depends on the relative gravitational time delay measured by spatially separated atomic clouds, we find that atom gradiometers are parametrically more sensitive than laser interferometers, such as LIGO and LISA, to fast-oscillating spacetime perturbations sourced by energy density and pressure fluctuations of ultralight dark matter. Depending on astrophysical backgrounds, a detector akin to AEDGE+ could probe a DM overdensity of $\mathcal{O}(10)$ times the local dark matter energy density for masses $m\lesssim 10^{-17}$~eV.

   hep-phastro-ph.COgr-qcPRD(2025)·12 citations
3. 03*

   Holographic Heavy Quark Energy Loss in the Hybrid Model

   Jean F. Du Plessis🇺🇸 · Daniel Pablos🇪🇸 · Krishna Rajagopal🇺🇸

   To date, holographic calculations in strongly coupled plasma have provided separate descriptions for the rates of energy loss either for ultrarelativistic massless quarks and gluons or for infinitely massive quarks, with the latter calculation valid for $\sqrt{\gamma }<M/(\sqrt{\lambda }T)$, where $\gamma$ is the Lorentz boost factor for a heavy quark with velocity $v$ and mass $M$ moving through plasma with 't Hooft coupling $\lambda$ and temperature $T$. These two calculations should apply sequentially in the description of the energy loss of a heavy quark that starts out ultrarelativistic, loses energy, slows down, becomes non-relativistic at later times, and ultimately comes to rest and diffuses in the strongly coupled plasma. We provide an ansatz for uniquely incorporating both regimes to give an approximate but unified description of how a heavy quark that is initially ultrarelativistic loses energy all the way until it comes to rest. We implement this ansatz in the Hybrid Strong/Weak Coupling Model. With this new, consistent, treatment of heavy quark energy loss at strong coupling, we confront our predictions for the suppression and azimuthal anisotropies of D- and B-mesons, as well as B-tagged jets, with available experimental data.

   hep-phnucl-thEPJ Web Conf.(2025)·0 citations
4. 04*

   Entanglement Maximization and Mirror Symmetry in Two-Higgs-Doublet Models

   Marcela Carena🇨🇦 · Guglielmo Coloretti🇨🇭 · Wanqiang Liu🇺🇸 · Mira Littmann🇺🇸 · Ian Low🇺🇸 · Carlos E. M. Wagner🇺🇸

   We consider 2-to-2 scatterings of Higgs bosons in a CP-conserving two-Higgs-doublet model (2HDM) and study the implication of maximizing the entanglement in the flavor space, where the two doublets ${\Phi }_a$, $a=1,2$, can be viewed as a qubit: ${\Phi }_1=|0⟩$ and ${\Phi }_2=|1⟩$. More specifically, we compute the scattering amplitudes for ${\Phi }_a{\Phi }_b\to {\Phi }_c{\Phi }_d$ and require the outgoing flavor entanglement to be maximal for a full product basis such as the computational basis, which consists of $\{|00⟩,|01⟩,|10⟩,|11⟩\}$. In the unbroken phase and turning off the gauge interactions, entanglement maximization results in the appearance of an $U(2)\times U(2)$ global symmetry among the quartic couplings, which in general is broken softly by the mass terms. Interestingly, once the Higgs bosons acquire vacuum expectation values, maximal entanglement enforces an exact $U(2)\times U(2)$ symmetry, which is spontaneously broken to $U(1)\times U(1)$. As a byproduct, this gives rise to Higgs alignment as well as to the existence of 6 massless Nambu-Goldstone bosons. The $U(2)\times U(2)$ symmetry can be gauged to lift the massless Goldstones, while maintaining maximal entanglement demands the presence of a discrete ${\mathrm{Z}}_2$ symmetry interchanging the two gauge sectors. The model is custodially invariant in the scalar sector, and the inclusion of fermions requires a mirror dark sector, related to the standard one by the ${\mathrm{Z}}_2$ symmetry.

   hep-phhep-thnucl-thquant-phJHEP(2025)·29 citations
5. 05*

   Hubble-induced phase transitions in the Standard Model and beyond

   Javier Rubio🇪🇸 · Giorgio Laverda🇵🇹

   We review the dynamics of spectator scalar fields non-minimally coupled to gravity in the post-inflationary Universe, with particular emphasis on scenarios where the end of inflation is followed by a period of kination. In this context, the evolution of the Ricci scalar can lead to the spontaneous breaking of discrete or continuous symmetries through tachyonic instabilities. These Hubble-induced phase transitions may cause the amplification of field fluctuations, the formation of transient topological defects, and an efficient energy transfer into relativistic degrees of freedom. We analyze this general mechanism and its cosmological consequences, including (re)heating and gravitational wave production. As a concrete realization, we discuss the postinflationary evolution of the Standard Model Higgs, examining the interplay between curvature effects, vacuum stability, and non-perturbative dynamics. This framework provides a minimal and predictive connection between high-energy physics and the early Universe, with potential observational signatures.

   hep-phastro-ph.COgr-qcPoS(2025)·5 citations
6. 06*

   Photoproduction and detection of ${\rho }^{\prime }\to {\pi }^{+}{\pi }^{-}{\pi }^{+}{\pi }^{-}$ decays in ultra-peripheral collisions and at an electron-ion collider

   Neha Devi🇺🇸 · Minjung Kim🇺🇸 · Spencer R. Klein🇺🇸 · Janet Seger🇺🇸

   Vector meson photoproduction is an important probe of nuclear structure. Light vector mesons are most sensitive to low$-x$ structure, as long as they are not too light for perturbative QCD calculations. The ${\rho }^{\prime }$ is of interest as an intermediate mass state (between the $\rho$ and $J/\psi$) that is easier to detect than the $\varphi$. Using HERA data on proton targets, we make projections for lead/gold targets in UPCs at the Large Hadron Collider and RHIC, and for $ep$ and $eA$ collisions at a future Electron-Ion Collider (EIC). We compare the UPC projections with ALICE data, and constrain the branching ratio divided by the square of the photon-${\rho }^{\prime }$ coupling. The data prefer large couplings and small branching ratio, probably less than 25\%. The photon-meson coupling predicted by generalized vector meson dominance does not fit the data. The HERA $ep$ and ALICE UPC $e$Pb data exhibit very similar $4\pi$ mass spectra, indicating that, if the system is composed of two resonances, the products of their photon couplings with their four-pion branching ratios are similar. The predicted rates are high for both UPCs and the EIC. The ${\rho }^{\prime }\to {\pi }^{+}{\pi }^{-}{\pi }^{+}{\pi }^{-}$ decay can be observed at the EIC with high efficiency. In $ep$ collisions at the highest energy, the forward B0 detector is needed to observe this channel down to the lowest achievable Bjorken$-x$ values.

   hep-phnucl-exPRC(2026)·4 citations
7. 07*

   Calculations of Di-Hadron Production via Two-Photon Processes in Relativistic Heavy-Ion Collisions

   Luobing Wang (1)🇨🇳 · Xinbai Li (1)🇨🇳 · Zebo Tang (1)🇨🇳 · Xin Wu (1)🇨🇳 · Wangmei Zha (1) ((1) State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei, China)🇨🇳

   Two-photon processes in relativistic heavy-ion collisions have emerged as a critical probe of quantum electrodynamics in ultra-intense electromagnetic fields, with recent focus extending beyond dileptons to hadronic final states. At present, quantitative studies of di-hadron production via two-photon interactions remain scarce. In this work, we employ the Equivalent Photon Approximation and the two-photon fusion measurements from \(e^{+}e^{-}\) collisions to obtain differential cross-section predictions for \(\pi^{+}\pi^{-}\), \(K^{+}K^{-}\), and \(p\bar{p}\) pairs produced in ultra-peripheral \(\mathrm{Au{+}Au}\) collisions at \(\sqrt{s_{NN}} = 200\,\text{GeV}\) within the STAR acceptance, as well as in \(\mathrm{Pb{+}Pb}\) collisions at \(\sqrt{s_{NN}} = 5.36\,\text{TeV}\) within typical LHC acceptance. The calculations deliver the unified baseline for light-meson and baryon pairs in this environment, supplying benchmarks for upcoming STAR and LHC measurements and guiding future systematic investigations of hadronic two-photon processes at RHIC and LHC facilities.

   hep-phJ.Phys.G(2026)·0 citations
8. 08*

   Influence of the residual magnetic field on the azimuthal distribution of final-state particles in photon-nuclear processes

   Zhan Zhang (1)🇨🇳 · Xin Wu (1)🇨🇳 · Xinbai Li (1)🇨🇳 · Wangmei Zha (1)🇨🇳 · Zebo Tang (1) ((1) State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei, China)🇨🇳

   In relativistic heavy-ion collisions, charged particles are accelerated to nearly the speed of light, and their external electromagnetic fields can be effectively approximated as quasi-real photons. These photons interact with another nucleus via photon-nuclear interactions, producing vector mesons. These vector mesons possess extremely low transverse momentum (pT ~ 0.1 GeV/c), distinguishing them from particles produced via hadronic interactions. STAR and ALICE have observed J/psi, rho0 and other vector mesons with very low pT, which are well described by photoproduction models. This unique characteristic of having extremely low transverse momentum allows them to serve as a novel experimental probe. Recent STAR results show that the equivalent photons in photoproduction processes are fully linearly polarized, affecting the azimuthal distribution of final-state particles like rho0 -> pi+ pi-. Since the polarization links to the initial collision geometry, the rho0 azimuthal modulation can probe nuclear structure. However, the post-collision magnetic field may deflect these particles, distorting the azimuthal distribution and complicating structure measurements. We simulated the distribution of residual magnetic fields over time under different collision conditions using UrQMD for Au+Au collisions at sqrt(sNN)=200 GeV and calculated their effects on the azimuthal modulation (<cos 2phi>) of photoproduced rho0. Our results show that in peripheral collisions, the field significantly alters the for photoproduced rho0 with pT ~ 0.1 GeV/c. This provides key insights for future nuclear structure studies via photoproduction in peripheral collisions.

   hep-phPRC(2025)·0 citations
9. 09*

   Probing Kaons as Light-Strange Tetraquarks through Spectral and Decay Dynamics

   Chetan Lodha🇮🇳 · Ajay Kumar Rai🇮🇳

   Motivated by the discovery of several kaon-like states observed at BESIII and LHCb, this study explores S-wave and P-wave tetraquark states with quark contents $ss\bar{s}\bar{q}$ and $sq\bar{q}\bar{q}$ using potential-based phenomenology. The tetraquarks are modeled as diquark-antidiquark systems in antitriplet-triplet and sextet-antisextet color configurations. The mass spectra are calculated using the Cornell potential, while decay properties are analyzed through Fierz rearrangement. A comparison with experimentally observed states is provided to enhance our understanding of light-light tetraquark systems with non-homogeneous quark compositions.

   hep-phFew Body Syst.(2026)·4 citations
10. 10*

    Valence quark properties of charged kaons in symmetric nuclear matter

    Reetanshu Pandey🇮🇳 · Satyajit Puhan🇮🇳 · Navpreet Kaur🇮🇳 · Arvind Kumar🇮🇳 · Suneel Dutt🇮🇳 · Harleen Dahiya🇮🇳

    We calculate the leading twist valence quark transverse momentum parton distribution functions (TMDs) and generalized parton distributions (GPDs) of the charged kaons in an isospin symmetric nuclear matter at zero temperature by employing the light-cone quark model. The medium modifications of the unpolarized TMDs and GPDs have been carried out by taking inputs from the chiral SU($3$) quark mean field model. The electromagnetic form factors (EMFFs) and charge radii have been calculated from the unpolarized GPDs for both the vacuum and in-medium cases. We have also calculated the variation of average transverse and longitudinal momenta for the active quark at high baryonic density. These results are found to be in good agreement with the available experimental data as well as with other model predictions.

    hep-phEur.Phys.J.Plus(2025)·2 citations
11. 11*

    EFT analysis of New Physics at COHERENT with Dirac neutrinos

    Víctor Bresó-Pla🇩🇪 · Sergio Cruz-Alzaga🇪🇸 · Martín González-Alonso🇪🇸 · Suraj Prakash🇪🇸

    We study the sensitivity of COHERENT-like experiments to non-standard contributions within the so-called $\nu$WEFT framework. The latter is the most general low-energy effective field theory that includes not only the light SM fields but also additional right-handed Dirac neutrinos. Our analysis includes for the first time flavor-general New Physics effects in neutrino production (pion and muon decays) and neutrino detection (through Coherent Elastic Neutrino-Nucleus Scattering). Despite the generality, the results can be written in compact form and are easy to implement in existing or future analyses using effective nuclear charges. We use current COHERENT data to set constraints on the corresponding effective operators, and we estimate the sensitivity of future measurements.

    hep-phJHEP(2025)·6 citations
12. 12*

    Semileptonic Decays of $D\to \rho l^{+}\nu$ and $D_{(s)}\to K^{\ast }{l}^{+}\nu$ from Light-Cone Sum Rules

    Wang Lin🇨🇳 · Xiao-En Huang🇨🇳 · Shan Cheng🇨🇳 · De-Liang Yao🇨🇳

    We investigate the semileptonic decays of charmed mesons to light vector mesons within the framework of light-cone sum rules. Our calculation is performed at leading order in QCD coupling, incorporating contributions up to twist-five accuracy from both two-particle and three-particle light-cone distribution amplitudes. Transition form factors are predicted twist by twist to assess the convergence property of the operator product expansion. It is verified that the twist-four and twist-five contributions are indeed negligible for all the decays under consideration. Twist-three dominance is observed for some of the form factors, subject to heavy quark effective field theory interpretation. Branching ratios for the decays $D^{+}\to {\rho }^0{\ell }^{+}{\nu }_{\ell }$ , $D_s^{+}\to K^{\ast 0}{\ell }^{+}{\nu }_{\ell }$, $D^0\to K^{\ast -}{\ell }^{+}{\nu }_{\ell }$ and $D^{+}\to {\bar{K}}^{\ast 0}{\ell }^{+}{\nu }_{\ell }$ are obtained, and a $10\%$--$20\%$ discrepancy from experimental measurements is found. Our finding indicates that the resonant-width and non-resonant QCD backgrounds effects should be potentially significant, implying the necessity to further implement their contributions in future precision studies of the semileptonic charm decays.

    hep-phhep-exPRD(2025)·11 citations
13. 13*

    Universality at next-to-leading power for jet associated processes

    Sourav Pal🇮🇳 · Satyajit Seth🇮🇳

    The study of cross-sections in the threshold limit at next-to-leading power has been a subject of sustained interest for many years. We demonstrate the universality of leading logarithms at next-to-leading power for the production of arbitrary massive colourless particles in association with a jet, contingent upon the identification of appropriate combination of helicity configurations.

    hep-phPRD(2025)·2 citations
14. 14*

    Identifying regions for asymptotic expansions of amplitudes: fundamentals and recent advances

    Yao Ma🇨🇭

    This review paper discusses the identification of regions, a crucial first step in applying the "method-of-regions" technique. A systematic approach based on Newton polytope geometry has proven successful and efficient for many cases. However, obtaining the correct list of regions becomes increasingly subtle with higher loop numbers or specific Feynman graph topologies. This paper explores the scenarios where such subtleties arise, outlines general strategies to address them, and reviews the current understanding of region structures in various asymptotic expansions of Feynman integrals.

    hep-phhep-thInt.J.Mod.Phys.A(2025)·17 citations
15. 15*

    Non-Standard Neutrino Interactions at Neutrino Experiments and Colliders

    Ayres Freitas🇺🇸 · Matthew Low🇺🇸

    The impact of new physics on the interactions of neutrinos with other particles can be parametrized by a set of effective four-fermion operators called non-standard neutrino interactions (NSIs). This NSI framework is useful for studying the complementarity between different types of neutrino experiments. In this work, we further compare the reach of neutrino experiments with high-energy collider experiments. Since high-energy colliders often probe the mass scale associated with the four-fermion operators, the effective field theory approach becomes invalid and explicit models must be utilized. We study a variety of representative simplified models including new U(1) gauge bosons, scalar leptoquarks, and heavy neutral leptons. For each of these, we examine the model parameter space constrained by NSI bounds from current and future neutrino experiments, and by data from the Large Hadron Collider and planned electron-positron and muon colliders. We find that in the models we study, with the possible exceptions of muon-philic leptoquarks and heavy neutral leptons mixing with electron or muon neutrinos, collider searches are more constraining than neutrino measurements. Additionally, we briefly comment on other model building possibilities for obtaining models where neutrino experiments are most constraining.

    hep-phJHEP(2025)·5 citations
16. 16*

    Dirac Scoto Inverse-Seesaw from $A_4$ Flavor Symmetry

    Ranjeet Kumar🇮🇳 · Newton Nath🇮🇳 · Rahul Srivastava🇮🇳 · Sushant Yadav🇮🇳

    We present a Dirac scotogenic-like one loop radiative model where the stability of dark matter is intricately linked to the breaking of $A_4$ flavor symmetry. This breaking induces a $Z_2$ dark symmetry, stabilizing the dark matter candidate. The breaking of $A_4\to Z_2$ leads to cutting the loop and facilitating a "scoto inverse-seesaw" mass mechanism responsible for neutrino mass generation. This elucidates the explicit explanation of two mass-squared differences, $\Delta m_{\mathrm{atm}}^2$ and $\Delta m_{\mathrm{sol}}^2$ observed in neutrino oscillations. Our model accounts for normal and inverted ordering of neutrino masses, revealing sharp correlations between $\sum m_i$ and $⟨m_{\beta }⟩$. It also shows strong compatibility with current data in the ${\delta }_{CP}$-${\theta }_{23}$ plane. Moreover, stringent constraints on scalar masses narrow down the viable dark matter mass regions, accommodating $SU(2{)}_L$ singlet and doublet scalar dark matter as well as fermionic dark matter. Additionally, our model presents a viable avenue for addressing lepton flavor violating decays while remaining consistent with current experimental constraints.

    hep-phhep-exJHEP(2025)·19 citations
17. 17*

    Neutrino mass generation in asymptotically safe gravity

    Gustavo P. de Brito🇧🇷 · Astrid Eichhorn🇩🇪 · Antonio D. Pereira🇧🇷 · Masatoshi Yamada🇯🇵

    There exist several distinct phenomenological models to generate neutrino masses. We explore, which of these models can consistently be embedded in a quantum theory of gravity and matter. We proceed by invoking a minimal number of degrees of freedom beyond the Standard Model. Thus, we first investigate whether the Weinberg operator, a dimension-five-operator that generates neutrino masses without requiring degrees of freedom beyond the Standard Model, can arise in asymptotically safe quantum gravity. We find a negative answer with far-reaching consequences: new degrees of freedom beyond gravity and the Standard Model are necessary to give neutrinos a mass in the asymptotic-safety paradigm. Second, we explore whether the type-I Seesaw mechanism is viable and discover an upper bound on the Seesaw scale. The bound depends on the mass of the visible neutrino. We find a numerical value of $10^{14}\mathrm{GeV}$ for this bound when neglecting neutrino mixing for a visible mass of $10^{-10}\mathrm{GeV}$. Conversely, for the most ``natural" value of the Seesaw scale in a quantum-gravity setting, which is the Planck scale, we predict an upper bound for the neutrino mass of the visible neutrino of approximately $10^{-15}\mathrm{GeV}$. Third, we explore whether neutrinos could also be Pseudo-Dirac-neutrinos in asymptotic safety and find that this possibility can be accommodated.

    hep-phgr-qchep-thPRD(2025)·10 citations
18. 18*

    Photo- and Hadrodisintegration constraints on massive relics decaying into neutrinos

    Sara Bianco🇩🇪 · Paul Frederik Depta🇩🇪 · Jonas Frerick🇩🇪 · Thomas Hambye🇧🇪 · Marco Hufnagel🇧🇪 · Kai Schmidt-Hoberg🇩🇪

    We perform a detailed study of the cosmological constraints on the decay of a relic particle $\varphi$ into neutrinos, $\varphi \to \nu \bar{\nu }$, in particular those arising from the observed light-element abundances in the early Universe. We focus on the late-time disintegration of the light elements previously synthesised during BBN. Several processes are relevant, including final-state radiation associated with the decay, as well as subsequent interactions of the injected neutrinos with the thermal background neutrinos or between themselves. All processes generically contribute to the production of electromagnetic and often also hadronic material and may therefore induce late-time photodisintegration and hadrodisintegration reactions, i.e.~the destruction of light elements that have previously been formed during BBN. Here, we examine this scenario with a Monte-Carlo inspired probabilistic approach rather than Boltzmann techniques, taking into account all of these different reactions as well as their interplay. We find the resulting constraints to be very significant, covering a broad range of previously unexplored masses and lifetimes of the relic source particle.

    hep-phastro-ph.COJCAP(2025)·8 citations
19. 19*

    Probing "Continuous Spin" QED with Rare Atomic Transitions

    Aidan Reilly🇺🇸 · Philip Schuster🇺🇸 · Natalia Toro🇺🇸

    An intriguing and elementary possibility is that familiar massless particles like the photon could be "continuous spin" particles (CSP) with a small but non-zero spin Casimir $\rho$. In this case, the familiar two polarization states of the photon are accompanied by an infinite tower of integer spaced helicity modes, with couplings dictated entirely by Lorentz symmetry and the parameter $\rho$. We present a formalism for computing bound state atomic transitions for scalar QED when $\rho \ne 0$, employing path integral methods not often used for bound state computations, but that readily generalize to the CSP case. We compute several illustrative amplitudes and show that $\rho \ne 0$ opens new decay channels for atomic transitions with rates controlled by $\rho \alpha /\omega$ for transition frequency $\omega$. These new channels can appreciably modify the rates of "forbidden" transitions. For example, the lifetime of the hydrogen $2s$ state would be affected at $O(1)$ for $\rho \sim 0.1$ eV, suggesting new directions for fundamental tests of QED in laboratory experiments.

    hep-phhep-thphysics.atom-phPRD(2026)·4 citations
20. 20*

    Soft Oscillons

    Fabio van Dissel🇪🇸 · Oriol Pujolàs🇪🇸

    We present a novel type of soliton dubbed soft oscillons. In contrast with conventional oscillons the soft counterparts come in a continuum of unboundedly large sizes. They are peculiar also in that the oscillation frequency is set by their size and in their high harmonic content, that leads to a peculiar core structure and pulsating emission of radiation. Soft oscillons appear in a broad class of scalar field theories with plateau potentials and owe their existence to a simple confinement mechanism: a large field perturbation automatically acts as a cavity that traps massless modes. We study the classical evaporation rate, lifetime and stability under anisotropic deformations. Soft oscillons are longer lived in gapless models, where lifetimes can reach 100 times the initial radius or more.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2025)·8 citations
21. 21*

    Summary Report of the Physics Beyond Colliders Study at CERN

    R. Alemany Fernández🇨🇭 · M. Au🇨🇭 · G. Arduini🇨🇭 · L. Bandiera🇮🇹 · D. Banerjee🇨🇭 · H. Bartosik🇨🇭 · J. Bernhard🇨🇭 · D. Boer🇳🇱 · J. Boyd🇨🇭 · O. Brandt🇬🇧 · M. Brugger🇨🇭 · O. Buchmüller🇬🇧 and 71 other authors

    The Physics Beyond Collider (PBC) Study Group was initially mandated by the CERN Management to prepare the previous European Particle Physics Strategy Update for CERN projects other than the high-energy frontier colliders. The main findings were summarized in an PBC Summary Report submitted to the Strategy Update. Following the Update process, the PBC Study Group was confirmed on a permanent basis with an updated mandate taking into account the strategy recommendations. The Study Group is now in charge of supporting the proponents of new ideas to address the technical issues and physics motivation of the projects ahead of their review by the CERN Scientific Committees and decision by the Management. The present document updates the previous PBC summary report to inform the new ongoing European Particle Physics Strategy Update process, taking into account the evolution of the CERN and worldwide landscapes and the new projects under consideration within the Study Group.

    ↳ hep-exhep-phnucl-ex26 citations
22. 22*

    Reheating ACTs on Starobinsky and Higgs inflation

    D.S. Zharov🇺🇦 · O.O. Sobol🇩🇪 · S.I. Vilchinskii🇺🇦

    In the recent sixth data release (DR6) of the Atacama Cosmology Telescope (ACT) collaboration, the value of $n_{\mathrm{s}}=0.9743\pm 0.0034$ for the scalar spectral index is reported, which excludes the Starobinsky and Higgs inflationary models at $2\sigma$ level. In this paper, we perform a Bayesian inference of the parameters of the Starobinsky or Higgs inflationary model with non-instantaneous reheating using the Markov chain Monte Carlo method. For the analysis, we use observational data on the cosmic microwave background collected by the Planck and ACT collaborations and on baryonic acoustic oscillations from the DESI collaboration. The reheating stage is modelled by a single parameter $R_{\mathrm{reh}}$. Using the modified Boltzmann code CLASS and the cobaya software with the GetDist package, we perform a direct inference of the model parameter space and obtain their posterior distributions. Using the Kullback--Leibler divergence, we estimate the information gain from the data, yielding $2.52$ bits for the reheating parameter. Inclusion of the ACT DR6 data provides $75\%$ more information about the reheating stage compared to analysis without ACT data. We draw constraints on the reheating temperature and the average equation of state. While the former can vary within $10$ orders of magnitude, values in the $95\%$ credible interval indicate a sufficiently low reheating temperature; for the latter there is a clear preference for values greater than $0.5$, which means that the conventional equations of state for dust $\omega =0$ and relativistic matter $\omega =1/3$ are excluded with more than $2\sigma$ level of significance. However, there still is a big part of parameter space where Starobinsky and Higgs inflationary models exhibit a high degree of consistency with the latest observational data, particularly from ACT DR6. Therefore, it is premature to reject these models.

    ↳ astro-ph.COgr-qchep-phPRD(2025)·86 citations
23. 23*

    Perturbative LVS and Inflation: A Review of Volume Modulus and Fibre Scenarios

    George K. Leontaris🇬🇷 · Pramod Shukla🇮🇳

    In type IIB superstring compactifications, incorporating log-loop corrections and higher-derivative ${({\alpha }^{\prime })}^3$-corrections can stabilize the overall volume of the compact internal space at exponentially large values. This mechanism forms the basis of the perturbative Large Volume Scenario (LVS). In this report, we briefly review two inflationary models realized within the perturbative LVS framework. The first one is the volume modulus inflation (also known as inflection point inflation) and the second one is popularly known as fibre inflation. Using an explict Calabi-Yau orientifold, some concrete global embeddings of both models are also discussed.

    ↳ hep-thhep-phPoS(2025)·6 citations
24. 24*

    Redshift-space galaxy bispectrum in presence of massive neutrinos: A multipole expansion approach for Euclid

    Sourav Pal🇮🇳 · Debanjan Sarkar🇨🇦 · Rickmoy Samanta🇮🇳 · Supratik Pal🇮🇳

    Massive neutrinos imprint distinctive signatures on the evolution of cosmic structures, notably suppressing small-scale clustering. We investigate the impact of massive neutrinos on the galaxy bispectrum in redshift-space, adopting a spherical harmonic multipole decomposition $B_L^m(k_1,\mu ,t)$, that captures the full angular dependence. We develop an analytical and numerical framework incorporating neutrino-corrected perturbation theory kernels and redshift-space distortions. Our results demonstrate that the linear triangle configurations are particularly sensitive to massive neutrinos, with deviations reaching up to $\sim 2\%$ for a total mass $\sum m_{\nu }=0.12\mathrm{eV}$. To assess detection prospects in galaxy surveys like \textit{Euclid}, we compute the signal-to-noise ratio (SNR) for individual multipoles, including the effects of Finger-of-God damping and shot noise. The neutrino-induced signatures in $B_0^0$ and $B_2^0$ are found to be detectable with SNR $\gtrsim 5$ across a range of configurations, even after accounting for small-scale suppression. Higher-order multipoles such as $B_2^1$ and $B_2^2$ are moderately sensitive, with SNR $\gtrsim$ ($2-3$) in squeezed limits, while hexadecapole moments are more suppressed but still exhibit measurable signals at high $k_1$. Additionally, the SNR generally increases with wave number $k_1$, particularly for squeezed and stretched triangles, suggesting that access to smaller scales significantly enhances detection prospects. Our study highlights the potential of the redshift-space bispectrum multipoles as sensitive probes of massive neutrinos, complementing traditional power spectrum analyses, and underscores the importance of angular information and higher-order statistics for galaxy surveys.

    ↳ astro-ph.COhep-phMNRAS(2025)·8 citations
25. 25*

    Gravitational Wave Memory of Primordial Black Hole Mergers

    Silvia Gasparotto🇪🇸 · Gabriele Franciolini🇨🇭 · Valerie Domcke🇨🇭

    The gravitational wave signal of binary compact objects has two main contributions at frequencies below the characteristic merger frequency: the gravitational wave signal associated with the early inspiral stage of the binary and the non-linear gravitational wave memory. We compare the sensitivity of upcoming gravitational wave detectors to these two contributions, with a particular interest in events with a merger phase at frequencies higher than the detector's peak sensitivity. We demonstrate that for light primordial black holes, current and upcoming detectors are more sensitive to the inspiral signal. Our analysis incorporates the evolution history of primordial black hole binaries, key to accurately estimating the relevant event rates. We also discuss the waveform templates of the memory signal at ground- and space-based interferometers, and the implications for a matched filtering search. This allows us to compare the sensitivity of high-frequency gravitational wave detectors, sensitive to the merger phase, with the sensitivity of existing interferometers.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2025)·11 citations
26. 26*

    Coupled-channel scattering of $DD,D{D}^{\ast }$ and $D^{\ast }{D}^{\ast }$ in isospin-$1$ from lattice QCD

    Nelson Pitanga Lachini🇬🇧 · Christopher E. Thomas🇬🇧 · David J. Wilson🇬🇧

    The first coupled-channel determination of two-body $D$ and $D^{\ast }$ scattering amplitudes in isospin-$1$ from lattice quantum chromodynamics is presented. Using three lattice volumes at $m_{\pi }\approx 391\mathrm{MeV}$, finite-volume energies relevant for the channels of interest are determined. Through the Lüscher formalism, these energies are used to constrain amplitudes of coupled $J^P=0^{+}$ $DD-D{D}^{\ast }$, $J^P=1^{+}$ $D{D}^{\ast }-D^{\ast }{D}^{\ast }$ and $J^P=2^{+}$ $DD-D{D}^{\ast }-D^{\ast }{D}^{\ast }$ scattering. All channels feature weakly repulsive interactions in $S$ wave, except for a weak $D^{\ast }{D}^{\ast }$ attraction in $J^P=0^{+}$. No amplitude singularities corresponding to physical states are found. Some of these amplitudes will be a necessary component of future lattice QCD analyses of $DD\pi$ and $D{D}^{\ast }$ scattering taking into account three-body and left-hand cut effects.

    ↳ hep-lathep-phPRD(2025)·8 citations
27. 27*

    Higher order flow coefficients -- A Messenger of QCD medium formed in heavy-ion collisions at the Large Hadron Collider

    Suraj Prasad🇮🇳 · Aswathy Menon K R · Raghunath Sahoo🇮🇳 · Neelkamal Mallick🇫🇮

    Anisotropic flow and fluctuations are sensitive observables of the initial state effects in heavy ion collisions and are characterized by the medium properties and final state interactions. Using event-shape observables, one can constrain the probability distributions of anisotropic flow coefficients, thus reducing the linear and nonlinear contributions in the measured higher-order harmonics. In this paper, we use transverse spherocity as an event shape observable to study the flow coefficients and elliptic flow fluctuations. Transverse spherocity is found to have a strong correlation with elliptic flow and its fluctuations. We exploit this feature of transverse spherocity to remove the contribution to elliptic flow from higher-order harmonics. The study is performed in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV using a multi-phase transport model. The multi-particle Q-cumulant method estimates the anisotropic flow coefficients, which reduces the non-flow contributions. We observe a stronger system response to the flow coefficients for the events with smaller values of elliptic flow.

    ↳ nucl-thhep-exhep-phnucl-exPLB(2025)·7 citations
28. 28*

    Exploring amplitude criteria for weak gravity in electroweak theory

    Tran Quang Loc🇸🇪

    Connections between weak gravity conjecture (WGC) bounds and scattering positivity have been extensively studied over the past decade. This work further explores these connections by proposing positivity as a potential amplitude criterion for weak gravity, with the aim of unifying various weak gravity bounds within a single framework. We illustrate this criterion by analyzing two-body elastic scatterings of photons and Higgs bosons in the forward limit of an electroweak (EW)-like theory. This leads to an amplitude-based criterion that extends magnetic WGC-type bounds to include not only the Abelian gauge coupling but also the non-Abelian gauge and the Yukawa coupling. Furthermore, a version of the species bound naturally emerges within this setup, suggesting that this amplitude criterion may extend to broader Swampland conjectures beyond the WGC.

    ↳ hep-thgr-qchep-ph0 citations
29. 29*

    The Sun's Dark Core: Helioseismic and neutrino flux constraints on a compact solar center

    Earl Patrick Bellinger🇺🇸 · Matt E. Caplan🇺🇸

    As dark matter appears to comprise most of the Galactic mass, some of it may accumulate in the cores of stars, thereby making the Sun a laboratory for constraining various dark matter theories. We consider the effects on the solar structure arising from a general class of macroscopic dark matter candidates that include strange quark matter, compact dark objects, and others. We calibrate standard solar evolution models (i.e., models that reproduce the mass, luminosity, radius, and metallicity of the Sun at its present age) with variable compact dark core masses ranging from $10^{-8}$ to $10^{-2}{\mathrm{M}}_{\odot }$ and assess their properties. We find that the weakest constraints come from solar neutrino flux measurements, which only rule out the most massive dark core comprising at least $\sim 1\%$ of the total solar mass. The Sun's acoustic oscillations impose stronger constraints, probing masses down to $\sim 10^{-5}{\mathrm{M}}_{\odot }$. We find that a model with a $10^{-3}{\mathrm{M}}_{\odot }$ dark core appears to improve the agreement with helioseismic observations. We nevertheless caution against interpreting this as evidence for dark matter in the solar interior, and suggest plausible effects that the dark core may instead be emulating. Finally, we show that future measurements of solar $g$~modes may constrain dark core masses down to $10^{-7}{\mathrm{M}}_{\odot }$.

    ↳ astro-ph.SRastro-ph.COhep-phApJ(2025)·2 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.