Fri·Apr 11, 2025Friday·April 11, 2025

1. 01*

   Probing the UV with IR Axion Dark Matter Experiments

   Jacob M. Leedom🇨🇿 · Serah Moldovsky🇺🇸 · Hitoshi Murayama🇺🇸

   There is an ongoing and future experimental program searching for axions as both extensions of the Standard Model and as candidates for the observed dark matter. In this paper, we examine the feasibility of being able to pin down precise features of axions within the context of this program. We define a set of infrared data that can be probed by experiments and explain how it encodes the ultraviolet data defining particular models of the QCD axion. We then critically examine the extent to which these data can be determined. If the parameters are favorable, we will be able to determine the axion couplings to photons, electrons, nuclei, as well as the dark matter halo density. However, further experimental proposals are needed to fully flesh out the ultraviolet model of the axion.

   hep-phJCAP(2026)·3 citations
2. 02*

   Strongly coupled inert scalar sector with radiative neutrino masses

   A. E. Cárcamo Hernández🇨🇱 · Jeremy Echeverria Puentes🇨🇱 · R. Pasechnik🇸🇪 · Daniel Salinas-Arizmendi🇨🇱

   We explore the phenomenological consequences of a model with an extended scalar sector, incorporating strongly coupled inert Higgs doublets. The model introduces three Higgs doublets: one that interacts with the $SU(2)$ symmetry of the Standard Model, and two inert doublets belonging to a strongly interacting sector, embedded in the $SU(2{)}_2\times SU(2{)}_1\times U(1{)}_Y$ electroweak gauge symmetry. This symmetry structure is further supplemented by a spontaneously broken ${\mathbb{Z}}_2$ and a preserved ${\mathbb{Z}}_2^{\prime }$ discrete symmetry. Our approach harnesses the exotic scalar fields emerging from this sector to implement mass-generation mechanisms. In particular, a one-loop seesaw mechanism accounts for the smallness of neutrino masses, while a universal seesaw mechanism naturally explains the hierarchy of charged fermion masses below the top quark mass. The model is shown to be consistent with current experimental constraints, including those from charged lepton flavor violation, electroweak precision observables, the Higgs diphoton decay rate, and the Higgs trilinear self-coupling. Notably, it also provides a viable interpretation of the 95~GeV diphoton excess, offering a distinctive signature of new physics beyond the Standard Model.

   hep-phJHEP(2025)·3 citations
3. 03*

   Empirical Determination of the Kaon Distribution Amplitude

   Lei Chang🇨🇳 · Yu-Bin Liu🇨🇳 · Khépani Raya🇪🇸 · M. Atif Sultan🇨🇳

   We propose a data-driven approach to extract the Kaon leading-twist distribution amplitude (DA) from empirical information on the ratio of the neutral-to-charged kaon electromagnetic form factors, ${\mathcal{R}}_K$. Our study employs a two-parameter representation of the DA at $\zeta =2$ GeV, designed to capture the expected broadening and asymmetry of the distribution, as well as the soft endpoint behavior predicted by quantum chromodynamics (QCD). Our leading-order analysis of the latest experimental measurements of ${\mathcal{R}}_K$ reveals that the extracted DA exhibits a somewhat significant skewness, with the first symmetric moment approximately $⟨1-2x{⟩}_K=0.082(7)$. On the other hand, the brodaness and general shape of the produced distributions show a reasonable consistency with contemporaty lattice and continuum QCD analyses. These findings highlight the importance of accurately determining the profile of the DA, especially the skewness and its relation to $S{U}_F(3)$ flavor symmetry breaking, as well as the inclusion of higher-order effects in the hard-scattering kernels for analyzing data at experimentally accessible scales.

   hep-phhep-latnucl-thPRD(2025)·3 citations
4. 04*

   Constraining the 3HDM Parameter Space using Active Learning

   Nipun Batra🇮🇳 · Baradhwaj Coleppa🇮🇳 · Akshat Khanna🇮🇳 · Santosh Kumar Rai🇮🇳 · Agnivo Sarkar🇮🇳

   One of the standard ways to study scenarios beyond the Standard Model involves extending the Higgs Sector. This work examines the Three Higgs Doublet Model (3HDM) in a Type-Z or democratic setup, where each Higgs doublet couples exclusively to a specific type of fermion. The particle spectrum of the 3HDM includes four charged Higgs bosons, two CP-odd scalars, and three CP-even scalars. This work investigates the allowed mass and coupling parameter space in the Type-Z 3HDM after imposing all theoretical and experimental constraints. We extract the allowed parameter space under three distinct alignment-limit conditions or mass hierarchies leveraging machine learning techniques. Specifically, we analyze scenarios where the 125 GeV Higgs is the lightest, an intermediary, or the heaviest CP-even Higgs boson. Our findings indicate that while a single lighter CP-even Higgs boson below 125 GeV still remains a possibility, the presence of two lighter Higgses is ruled out.

   hep-phPRD(2025)·13 citations
5. 05*

   Probing fluctuating protons using forward neutrons in soft and hard inelastic proton-nucleus scattering

   M. Alvioli (CNR IRPI, Perugia and INFN, Perugia)🇮🇹 · V. Guzey (Jyvaskyla U. and Helsinki Inst. of Phys., Helsinki U.)🇫🇮 · M. Strikman (Penn State U.)🇺🇸

   We present a model for the distribution of the number of forward neutrons emitted in soft (minimum bias) and hard inelastic proton-nucleus ($pA$) scattering at the LHC. It is based on the Gribov-Glauber model for the distribution over the number of inelastic collisions (wounded nucleons) combined with a parametrization of cross section (color) fluctuations in the projectile proton, which depend on the parton momentum fraction $x_p$, and the assumption of independent neutron emissions. We observe that while the effect of soft color fluctuations is modest, a reduction of the interaction strength with increasing $x_p$ provides the dominant effect. It allows us to qualitatively describe the trend of the ATLAS data on the ZDC energy spectra of forward neutrons emitted in dijet production in inelastic $pA$ scattering at $\sqrt{s_{NN}}=8.16$ TeV.

   hep-phhep-exnucl-exPRC(2025)·2 citations
6. 06*

   $C$ and $CP$ violation in effective field theories and applications to $\eta$-meson decays

   Bastian Kubis🇩🇪

   The quest for sources of the simultaneous violation of $C$ and $CP$ symmetry was popular in the 1960s, but has since been neglected for a long time. We revisit the operators that break $C$ and $CP$ for flavor-conserving transitions in both the Standard Model effective field theory and the low-energy effective field theory, which subsequently can be matched to light-meson physics using chiral perturbation theory. As applications, we discuss in particular the $C$-odd Dalitz plot asymmetries in $\eta \to 3\pi$, but also decays with dilepton pairs in the final state, such as long-distance contributions to the rare semileptonic decays $\eta \to {\pi }^0{\ell }^{+}{\ell }^{-}$ as well as asymmetries in ${\eta }^{(\prime )}\to \gamma {\ell }^{+}{\ell }^{-}$ and ${\eta }^{(\prime )}\to {\pi }^{+}{\pi }^{-}{\ell }^{+}{\ell }^{-}$.

   hep-phhep-exnucl-thPoS(2026)·0 citations
7. 07*

   Axion dark matter search from terrestrial magnetic fields at extremely low frequencies

   Atsushi Nishizawa🇯🇵 · Atsushi Taruya🇯🇵 · Yoshiaki Himemoto🇯🇵

   The natural environment of the Earth can act as a sensitive detector for dark matter in ultralight axions. When axions with masses between $1\times 10^{-15}\mathrm{eV}$ and $1\times 10^{-13}\mathrm{eV}$ pass through the Earth, they interact with the global geomagnetic field, generating electromagnetic (EM) waves in the extremely low-frequency range ($0.3$--$30\mathrm{Hz}$) through axion-photon coupling. This paper is one of a series of companion papers for~\cite{Taruya:2025zql}, focusing on the data analysis method and search results for an axion signal. Utilizing the theoretical predictions of axion-induced EM spectra from a companion study, we analyzed long-term observational data of terrestrial magnetic fields in this frequency band to search for axion-induced signals. Our analysis identified 65 persistent signal candidates with a signal-to-noise ratio (SNR) greater than 3. Aside from these candidates, we placed a new upper bound on the axion-photon coupling parameter, significantly refining the previous constraint from CAST by at most two orders of magnitude down to $g_{a\gamma }\lesssim 4\times 10^{-13}{\mathrm{GeV}}^{-1}$ for the axion mass around $3\times 10^{-14}\mathrm{eV}$.

   hep-phastro-ph.COPTEP(2026)·14 citations
8. 08*

   Strong Decays of Charmonia

   Zaki Ahmad🇵🇰 · Ishrat Asghar🇵🇰 · Faisal Akram🇵🇰 · Bilal Masud🇵🇰

   In this work, we calculate the charmonium spectrum and strong decay widths of cc states. The calculations are performed using the quark potential model with which incorporates the relativistic effects. The resulting cc spectrum exhibits a good agreement with experimental data. The open flavor strong decay widths are calculated employing the 3P0 model. We adopt two choices of wave functions to determine the observables: the first involves the utilization of realistic wave functions obtained by solving relativistic Schrodinger equation, while the second employs Simple harmonic oscillator (SHO) wave functions whose parameters are fitted to the realistic wave functions. We find that the decay widths of higher charmonia states above the threshold value of open charm mesons are well described with these wave functions. We provide a comprehensive analysis of the strong decay widths and assigned specific charmonium states: X(3940) is assigned to the {\eta}c(3S) state, Y (4660) to the {\psi}(5S) state, X(3915) to the ḩi}0(2P) state, Zc(3900) to the hc(2P) state, X(4350) to the ḩi}2(3P) state, and X(3842) to the {\psi}3(1D) state. We also compare our results with available experimental data and theoretical predictions of other models.

   hep-phPRD(2025)·5 citations
9. 09*

   Production mechanism of hidden-charm pentaquark states $P_{c\bar{c}s}$ with strangeness $S=-1$

   Samson Clymton🇰🇷 · Hyun-Chul Kim🇰🇷 · Terry Mart🇮🇩

   We investigate the hidden-charm pentaquark states with strangeness $S=-1$ ($P_{c\bar{c}s}$) within an off-shell coupled-channel approach based on effective Lagrangians that respect heavy-quark spin symmetry, SU(3) flavor symmetry, and hidden local symmetry. All relevant meson-baryon two-body channels composed of low-lying anti-charmed mesons and singly-charmed baryons with $S=-1$, as well as the $J/\psi \Lambda$ channel, are included. We find a total of eleven negative-parity states and three positive-parity states. Among the negative-parity states, the $P_{c\bar{c}s}(4338)$ and $P_{c\bar{c}s}(4459)$ can possibly be interpreted as $\bar{D}{\Xi }_c$ and ${\bar{D}}^{\ast }{\Xi }_c$ molecular states, respectively. We identify a second state, $P_{c\bar{c}s}(4472)$, located close to the $P_{c\bar{c}s}(4459)$ but with different spin and width, which may correspond to the structure observed by the Belle Collaboration. Both states are generated from the ${\bar{D}}^{\ast }{\Xi }_c$ channel and can be interpreted as spin partners. Their properties are consistent with recent experimental observations, providing strong support for the molecular interpretation of the $P_{c\bar{c}s}$ states. We also observe a two-pole structure near the ${\bar{D}}_s^{\ast }{\Lambda }_c$ and $\bar{D}{\Xi }_c^{{}^{\prime }}$ thresholds, and find virtual and resonance states in the ${\bar{D}}^{\ast }{\Xi }_c^{{}^{\prime }}$ channel depending on spin-parity.

   hep-phhep-exPRD(2025)·13 citations
10. 10*

    Electroweak baryogenesis in 2HDM without EDM cancellation

    Masashi Aiko🇯🇵 · Motoi Endo🇯🇵 · Shinya Kanemura🇯🇵 · Yushi Mura🇯🇵

    We study two Higgs doublet models with successful electroweak baryogenesis but without cancellations of electric dipole moments (EDMs). For the baryogenesis, additional scalar bosons are favored to couple mainly with the top quark with CP violations. However, if they also couple to light fermions of the Standard Model, the model is limited severely by EDMs, and additional CP phases irrelevant to the baryogenesis are often introduced to cancel the contributions to the EDMs. Alternatively, we consider a scenario where the light-fermion couplings are suppressed to avoid the constraints. In our scenario, it is found that the leading contributions arise in the top-quark EDMs at the two-loop level. They induce the electron, neutron, and proton EDMs via radiative corrections. Since there is no additional CP-violating phase, they are correlated with the baryon asymmetry. We show that our scenario is compatible with the current experimental bounds and is within the scope of future EDM experiments.

    hep-phJHEP(2025)·14 citations
11. 11*

    Inflection Point Inflation in Supergravity

    Manuel Drees🇩🇪 · Wenbin Zhao🇩🇪

    In this paper, we study the inflection point inflation generated by a polynomial superpotential and a canonical Kähler potential under the supergravity framework, where only one chiral superfield is needed. We find that the special form of the scalar potential limits the inflationary Hubble parameter to values $\lesssim 10^{10}\text{GeV}$ and the inflaton mass to $\lesssim 10^{11}\text{GeV}$. We obtain analytic results for small field cases and present numerical results for large field ones. We find the tensor-to-scalar ratio $r<10^{-8}$ is always suppressed in these models, while the running of spectral index $\alpha \approx \mathcal{O}(-10^{-3})$ may be testable in next-generation CMB experiments. We also discuss the possible effects of SUSY breaking Polonyi term presented in the superpotential where we find a general upper bound for the SUSY breaking scale for a given value of the Hubble parameter.

    hep-phJCAP(2025)·1 citation
12. 12*

    The effect of background matter on the spin oscillations of neutrinos scattered by the supermassive black hole

    Mridupawan Deka🇷🇺 · Maxim Dvornikov🇷🇺

    We study spin oscillations of neutrinos in relativistic moving matter inside an accretion disk. These neutrinos are gravitationally scattered off a spinning Kerr black hole surrounded by a thick accretion disk. The disk can co-rotate and counter-rotate with respect to BH spin. We perform numerical simulations of the propagation of a large number of incoming test neutrinos. We briefly discuss our results.

    hep-phastro-ph.HEgr-qc0 citations
13. 13*

    Testing Leptogenesis from Observable Gravitational Waves

    Wei Liu🇨🇳 · Yongcheng Wu🇨🇳

    Leptogenesis provides an elegant mechanism to explain the observed baryon asymmetry of the Universe (BAU), yet its experimental verification remains challenging due to requirements of either extremely heavy right-handed neutrinos or precisely fine-tuned mass splittings. We adapt a solution by introducing an extra scalar field that significantly enhances $CP$ asymmetry through loop-level contributions. This scalar extension not only facilitates successful leptogenesis but also enables a strong first-order electroweak phase transition, generating potentially observable gravitational waves (GWs). We demonstrate a strong correlation between the generated BAU and the GW signal strength, establishing a unique way to test the leptogenesis. We show that when the model achieves a successful BAU, the resulting GW signal from EWPT can have signal-to-noise ratio of $\mathcal{O}(10^3)$ and $\mathcal{O}(10^6)$ at the upcoming LISA and DECIGO experiments, respectively. This work presents a concrete connection between successful leptogenesis and detectable GWs, offering a promising method for experimental testing of the leptogenesis mechanism through future GW observations.

    hep-ph4 citations
14. 14*

    Non-equilibrium dynamics of long-range field configurations in the Proca theory and the counterexample to the law of periodic charge oscillations

    Bogdan Damski🇵🇱

    Long-range field configurations exist in the Proca theory and their non-equilibrium evolution is of interest in this work. General arguments suggest that a charge can be assigned to them and that its evolution is governed by the law of periodic charge oscillations. We discuss an elegant analytically-solvable example of a field configuration in the Proca theory respecting such a law. We also identify a weak point in the aforementioned general arguments, construct the counterexample to the law of periodic charge oscillations in the Proca theory, and comprehensively discuss it. The Gibbs-Wilbraham phenomenon is discussed in the course of these studies.

    hep-phhep-thNPB(2025)·0 citations
15. 15*

    $B$ meson semileptonic decays from lattice QCD

    Alejandro Vaquero Aviles-Casco🇪🇸

    $B$ processes are a rich source of potential anomalies that could lead to the discovery of BSM physics. The long-standing tension between the inclusive and the exclusive determinations of the CKM matrix elements $|V_{xb}|$, or the current tensions in the $R(D)$-$R(D^{\ast })$ plane are some examples of active areas of research where we might find signals of new physics. Heavy-to-heavy $B$ semileptonic decays, $B_{(s)}\to D_{(s)}^{(\ast )}\ell \nu$, and in particular, decays with a vector product ($D_{(s)}^{\ast }$) are especially interesting from an experimental point of view, but experiment and theory must walk together in order to reach conclusions in the intensity frontier. In this review I talk about the current status of the lattice-QCD calculations of the $B\to D^{\ast }\ell \nu$ form factors at non-zero recoil, I discuss the implications they have for the determination of $B$ anomalies, and finally I give some hints of what we can expect from future calculations.

    hep-phhep-latPoS(2025)·0 citations
16. 16*

    Conversion-Driven Freeze-Out: A Common Framework for Dark Matter and Baryogenesis

    Jan Heisig🇩🇪

    We explore dark matter genesis beyond the WIMP paradigm, focusing on the mechanism of conversion-driven freeze-out. This mechanism enables the thermalization of dark matter despite its very weak couplings. While the scenario evades conventional WIMP searches, it predicts novel signatures of long-lived particles at colliders, making it a prime target for upcoming LHC searches. We review various model realizations of this mechanism, highlighting its deep connections to other unresolved problems of the Standard Model. In particular, we show how conversion-driven freeze-out can naturally give rise to baryogenesis, offering a compelling perspective on the origins of both dark and baryonic matter.

    hep-ph1 citation
17. 17*

    The Constituent Quark Model

    D.R. Entem🇪🇸 · F. Fernández🇪🇸 · P.G. Ortega🇪🇸 · J. Segovia🇪🇸

    In this chapter we give a pedagogical introduction to the constituent quark model. The explanation of magnetic moments of the nucleons was crucial to introduce an effective quark mass for light quarks that nowadays are understood as an effect of Spontaneous Chiral Symmetry Breaking in QCD. We give an overview of the first applications of the model and an introduction to the most modern developments studying states beyond the naive quark model as tetraquarks and pentaquarks.

    hep-phnucl-th8 citations
18. 18*

    Biased domain walls: faster annihilation, weaker gravitational waves

    E. Babichev🇫🇷 · I. Dankovsky🇷🇺 · D. Gorbunov🇷🇺 · S. Ramazanov🇷🇺 · A. Vikman🇨🇿

    We study the evolution of domain wall networks and their phenomenological implications in a model of a real scalar $\chi$, where a $Z_2$-symmetry is slightly broken by a potential bias $V_{bias}$. It is demonstrated that the latter triggers domain wall annihilation considerably earlier than previously thought. Namely, we observe that the scaling relation $t_{ann}\propto 1/V_{bias}^{2/3}$ for the annihilation time $t_{ann}$ fits to the simulation data better than a commonly assumed $t_{ann}\propto 1/V_{bias}$. As a result, the energy density of gravitational waves produced by the network of biased domain walls, for a given tiny $V_{bias}$, is suppressed compared to naive expectations. The spectral shape of gravitational waves is similar to that resulting from unbiased domain walls, but with more power in the close-to-maximum ultraviolet part. In the far ultraviolet region, the spectrum of gravitational waves becomes nearly flat; such a plateau has been recognised earlier in the case of unbiased walls. In our investigation we mainly focus on the symmetry breaking potential $V_{breaking}\propto {\chi }^3$, and argue that no significant modifications of the domain walls evolution take place if one includes higher powers of $\chi$.

    hep-phastro-ph.COhep-thJCAP(2025)·22 citations
19. 19*

    A dark matter hail: Detecting macroscopic dark matter with asteroids, planetary rings, and craters

    Zachary S. C. Picker🇺🇸

    Dark matter could be composed of macroscopic objects with large masses and geometric cross-sections spanning many decades. We investigate the potential interaction of such `stuff-sized' dark matter by considering its interactions with asteroids, planetary rings, and terrestrial bodies. This hail of dark matter could catastrophically destroy these Solar System objects, evaporate them from their orbits, or cause substantial cratering. We estimate these effects and use them to place competitive bounds on a wide, previously-unconstrained swathe of the dark matter parameter space.

    ↳ astro-ph.COastro-ph.EPhep-phPRD(2025)·4 citations
20. 20*

    Dynamical dark energy with AdS-dS transitions vs. Baryon Acoustic Oscillations at $z=$ 2.3-2.4

    Özgür Akarsu🇹🇷 · Maxim Eingorn · Leandros Perivolaropoulos🇬🇷 · A. Emrah Yükselci🇹🇷 · Alexander Zhuk🇩🇪

    In this paper, written in memory of Alexei Starobinsky, we discuss the observational viability of the Ph-${\Lambda }_{\mathrm{s}}$CDM model - a dynamical dark energy scenario based on a phantom scalar field undergoing an anti-de Sitter (AdS) to de Sitter (dS) transition - and revisit the Sahni-Shtanov braneworld model in light of updated BAO Ly-$\alpha$ data at $z\sim 2.3$. Both models are able to remain consistent with Planck CMB data while offering potential resolutions to the $H_0$ tension. In both cases, the expansion rate $H(z)$ is suppressed relative to Planck-$\Lambda$CDM at high redshift and enhanced at low redshift, while remaining consistent with the comoving distance to recombination as estimated by Planck-$\Lambda$CDM. Comparing model predictions with BAO-inferred values of $H(z)$, we find that SDSS Ly-$\alpha$ data at $z\approx 2.33$ mildly favor such dynamical models, whereas the recent DESI Ly-$\alpha$ measurements agree more closely with $\Lambda$CDM. Although current high-redshift BAO data do not decisively favor one model over another, our findings illustrate how frameworks originally developed to address earlier anomalies - such as the braneworld scenario - may gain renewed relevance in confronting today's cosmological tensions.

    ↳ astro-ph.COgr-qchep-phhep-th22 citations
21. 21*

    ${\Xi }_c\to \Xi$ form factors from lattice QCD with domain-wall quarks: A new piece in the puzzle of ${\Xi }_c^0$ decay rates

    Callum Farrell🇺🇸 · Stefan Meinel🇺🇸

    We present a lattice-QCD determination of the vector and axial-vector form factors that describe the charm-baryon semileptonic decays ${\Xi }_c\to \Xi {\ell }^{+}{\nu }_{\ell }$. The calculation uses a domain-wall action for the up, down, and strange quarks, and an anisotropic clover action for the charm quark. We use four ensembles of gauge-field configurations generated by the RBC and UKQCD collaborations, with lattice spacings between 0.111 and 0.073 fm and pion masses ranging from 430 to 230 MeV. We present Standard-Model predictions for the decay rates and branching fractions of ${\Xi }_c^0\to {\Xi }_c^{-}{\ell }^{+}{\nu }_{\ell }$ and ${\Xi }_c^{+}\to {\Xi }_c^0{\ell }^{+}{\nu }_{\ell }$ for $\ell =e,\mu$. In particular, we obtain $\Gamma ({\Xi }_c^0\to {\Xi }^{-}{e}^{+}{\nu }_e)/|V_{cs}{|}^2=0.2515(73){\text{ ps}}^{-1}$ and $\mathcal{B}({\Xi }_c^0\to {\Xi }^{-}{e}^{+}{\nu }_e)=3.58(12)\%$. These values are higher than those predicted by a previous lattice calculation and substantially higher than the experimentally measured values, but consistent with expectations from approximate $SU(3)$ flavor symmetry.

    ↳ hep-lathep-exhep-phPRD(2025)·10 citations
22. 22*

    Parton Distribution Functions in the Schwinger model from Tensor Network States

    Mari Carmen Bañuls🇩🇪 · Krzysztof Cichy🇵🇱 · C.-J. David Lin🇹🇼 · Manuel Schneider🇹🇼

    Parton distribution functions (PDFs) describe the inner, non-perturbative structure of hadrons. Their computation involves matrix elements with a Wilson line along a direction on the light cone, posing significant challenges in Euclidean lattice calculations, where the time direction is not directly accessible. We propose implementing the light-front Wilson line within the Hamiltonian formalism using tensor network techniques. The approach is demonstrated in the massive Schwinger model (quantum electrodynamics in 1+1 dimensions), a toy model that shares key features with quantum chromodynamics. We present accurate continuum results for the fermion PDF of the vector meson at varying fermion masses, obtained from first-principle calculations directly in Minkowski space. Our strategy also provides a useful path for quantum simulations and quantum computing.

    ↳ hep-lathep-phhep-thphysics.comp-ph+1PRD(2026)·21 citations
23. 23*

    Assessing cosmological evidence for non-minimal coupling

    William J. Wolf🇬🇧 · Carlos García-García🇬🇧 · Theodore Anton🇬🇧 · Pedro G. Ferreira🇬🇧

    The recent observational evidence of deviations from the $\Lambda$-Cold Dark Matter ($\Lambda$CDM) model points towards the presence of evolving dark energy. The simplest possibility consists of a cosmological scalar field $\phi$, dubbed quintessence, driving the accelerated expansion. We assess the evidence for the existence of such a scalar field. We find that, if the accelerated expansion is driven by quintessence, the data favour a potential energy $V(\phi )$ that is concave, i.e., $m^2=d^{2}V/d{\phi }^2<0$. Furthermore, and more significantly, the data strongly favour a scalar field that is non-minimally coupled to gravity (Bayes factor $\log (B)=7.34\pm 0.6$), leading to time variations in the gravitational constant on cosmological scales, and the existence of fifth forces on smaller scales. The fact that we do not observe such fifth forces implies that either new physics must come into play on non-cosmological scales or that quintessence is an unlikely explanation for the observed cosmic acceleration.

    ↳ astro-ph.COgr-qchep-phhep-thPRL(2025)·151 citations
24. 24*

    Exploratory calculation of the rare hyperon decay ${\Sigma }^{+}\to p{\ell }^{+}{\ell }^{-}$ from lattice QCD

    Felix Erben🇨🇭 · Vera Gülpers🇬🇧 · Maxwell T. Hansen🇬🇧 · Raoul Hodgson🇩🇪 · Antonin Portelli🇬🇧

    The rare hyperon decay ${\Sigma }^{+}\to p{\ell }^{+}{\ell }^{-}$ is a flavour-changing neutral current process mediated by an $s\to d$ transition that occurs only at loop level within the Standard Model. Consequently, this decay is highly suppressed, making it a promising avenue for probing potential new physics. While phenomenological calculations have made important progress in predicting the decay amplitude, there remains a four-fold ambiguity in the relevant transition form factors that prevents a unique prediction for the branching fraction and angular observables. Fully resolving this ambiguity requires a first-principles Standard-Model calculation, and the recent observation of this process using LHCb Run 2 data reinforces the timeliness of such a calculation. In this work, we present the first lattice-QCD calculation of this decay, performed using a 2+1-flavour domain-wall fermion ensemble with a pion mass of 340 MeV. At a small baryon source-sink separation, we observe the emergence of a signal in the relevant baryonic four-point functions. This allows us to determine the positive-parity form factors for the rare hyperon decays from first-principles, albeit with large statistical and systematic uncertainties.

    ↳ hep-lathep-phJHEP(2025)·6 citations
25. 25*

    Quantum Gravity Meets DESI: Dynamical Dark Energy in Light of the Trans-Planckian Censorship Conjecture

    Chunyu Li🇨🇳 · Junkai Wang🇺🇸 · Dongdong Zhang🇨🇳 · Emmanuel N. Saridakis🇬🇷 · Yi-Fu Cai🇨🇳

    Recent DESI DR2 observations indicate that dark energy has crossed from phantom to quintessence regime, a behavior known as the quintom-B realization. In this work we constrain dynamical dark energy and modified gravity using the swampland Trans-Planckian Censorship Conjecture (TCC), which forbids eternal acceleration since in this case any trans-Planckian quantum fluctuation would eventually stretch beyond the Hubble radius, breaking the applicability of any effective field theory and cosmological techniques. By combining DESI DR2 data with the TCC criterion, we impose tight constraints on the dark energy equation of state and its parameter space in scenarios such as the Chevallier-Polarski-Linder, Barboza-Alcaniz, Jassal-Bagla-Padmanabhan, EXP and LOG parameterizations, significantly constraining the quintom-A behavior. Also we examine models within the framework of $f(T)$ and $f(Q)$ modified gravity theories, demonstrating that TCC is very powerful to constrain or exclude them, a result that indicates the necessity to consider infrared modifications on General Relativity apart from the usual ultraviolet ones. Our findings imply that viable dynamical dark energy scenarios must asymptotically transit to deceleration, shedding light on new physics consistent with both cosmological observations and quantum gravity principles.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2025)·53 citations
26. 26*

    Large anisotropies in the gravitational wave background from baryogenesis

    Yan-Heng Yu🇨🇳 · Sai Wang🇨🇳

    Affleck-Dine (AD) baryogenesis can produce the baryon asymmetry of the Universe through the $CP$-violating dynamics of AD field. The field generally fragments into Q-balls, whose rapid decay induces enhanced gravitational waves. In this Letter, we investigate the anisotropies in this gravitational wave background as a new essential observable for AD baryogenesis. The evolution of AD field causes non-Gaussian baryonic isocurvature perturbations, and the non-Gaussianity modulates the spatial distribution of Q-balls on large scales, resulting in large-scale anisotropies in the Q-ball-induced gravitational wave background. We present that the anisotropies can be significantly large with a reduced angular power spectrum $\sim 10^{-2}$, and can be detected by future experiments like LISA. Moreover, these anisotropies universally reveal the $CP$-violating dynamics of AD field, opening a novel road to explore the longstanding baryon asymmetry puzzle.

    ↳ astro-ph.COgr-qchep-ph11 citations
27. 27*

    Resummation of Universal Tails in Gravitational Waveforms

    Mikhail M. Ivanov🇺🇸 · Yue-Zhou Li🇺🇸 · Julio Parra-Martinez🇫🇷 · Zihan Zhou🇺🇸

    We present a formula for the universal anomalous scaling of the multipole moments of a generic gravitating source in classical general relativity. We derive this formula in two independent ways using effective field theory methods. First, we use the absorption of low frequency gravitational waves by a black hole to identify the total multipole scaling dimension as the renormalized angular momentum of black hole perturbation theory. More generally, we show that the anomalous dimension is determined by phase shifts of gravitational waves elastically scattering off generic source multipole moments, which reproduces the renormalized angular momentum in the particular case of black holes. The effective field theory approach thus clarifies the role of the renormalized angular momentum in the multipole expansion. The universality of the point-particle effective description of compact gravitating systems further allows us to extract the universal part of the anomalous dimension, which is the same for any object, including black holes, neutron stars, and binary systems. As an application, we propose a novel resummation of the universal short-distance logarithms (``tails'') in the gravitational waveform of binary systems, which may improve the modeling of signals from current and future gravitational wave experiments.

    ↳ hep-thastro-ph.HEgr-qchep-phPRL(2025)·42 citations
28. 28*

    Stupendously Large Primordial Black Holes from the QCD axion

    Miguel Faria🇵🇹 · Ricardo Z. Ferreira🇵🇹 · Fabrizio Rompineve🇪🇸

    The inflationary diffusion of (pseudo-)scalar fields with discrete symmetries can seed the formation of a gas of closed domain walls after inflation, when the distance between degenerate minima in field space is not too far from the inflationary Hubble scale. Primordial black holes (PBHs) can then be formed once sufficiently heavy domain walls re-enter the Hubble sphere. In this scenario, inflation determines a distinctive PBH mass distribution that is rather flat and can thus lead to a sizable total abundance of PBHs, while avoiding some of the downsides of PBH formation from critical collapse. We show that generic QCD axion models, with decay constant close to the inflationary Hubble scale, can yield up to $1\%$ of the dark matter (DM) today in the form of PBHs, while being compatible with isocurvature constraints from Cosmic Microwave Background observations. This occurs for values of axion decay constants around $f_a\simeq 10^8\text{GeV}$, that is the region targeted by axion helioscopes and partially constrained by astrophysical observations. The resulting PBHs have \textit{stupendously} large masses, above $10^{11}{M}_{\odot }$, and their existence can be probed by Large Scale Structure observations. Larger PBH abundances can be generated by axion-like particles. Alternatively, in scenarios where isocurvature constraints can be relaxed, we find that the totality of the DM can be produced by the QCD axion misalignment mechanism, accompanied by a $\mathcal{O}(10^{-3})$ DM fraction in PBHs of masses $(10^5-10^6)M_{\odot }$. These can act as seeds for the formation of massive black holes at large redshifts, as suggested by recent JWST observations.

    ↳ astro-ph.COhep-phJCAP(2025)·3 citations
29. 29*

    Dark matter decay signals in cosmic filaments

    Elena Pinetti🇺🇸 · Evan Vienneau🇨🇦 · Nassim Bozorgnia🇨🇦

    Cosmic filaments form the backbone of the cosmic web, yet their properties and evolution remain uncertain. Using the EAGLE hydrodynamical simulations, we investigate the dark matter density profiles in filaments and their implications for dark matter decay signals. We show that GeV-scale dark matter particles decaying into electron-positron pairs can produce detectable radio synchrotron emission. By leveraging stacked filament radio data, we place stringent constraints on the dark matter decay lifetime, improving existing limits by up to two orders of magnitude for strong filamentary magnetic fields.

    ↳ astro-ph.COhep-phPRD(2026)·1 citation
30. 30*

    Effective-Field Theories of Analogue Gravity

    Alessia Biondi🇮🇹

    We develop a novel method for building a gravitational analog model for a flowing Bose-Einstein condensate. The analogue metric is obtained using effective field theory methods, integrating out the heavy radial fluctuations. In this way, we also obtain interaction terms up to the quartic order in the fields. The microscopic Lagrangian describes a complex massive scalar field, with a global U(1) symmetry, that is spontaneously broken. From the quadratic effective Lagrangian, we obtain a dispersion law for phonons in presence of an acoustic horizon generated by the background flow. We observe that the phonon dispersion relation may exhibit a non-monotonic behavior determined by the Lagrangian's parameters. In this case, a non-trivial minimum appears associated with a characteristic length scale, indicating the breaking of translation symmetry. Then, we determine the constraints on the Lagrangian's parameters to make this happen. Finally, we design an original procedure to calculate the correlation functions through field theory tools. We apply this method to the density-density correlation function, reproducing known results. Moreover, we study the case of a non-monotonic phonon dispersion law, finding the existence of long range order.

    ↳ gr-qccond-mat.quant-gashep-ph1 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.