Fri·Jul 26, 2024Friday·July 26, 2024

1. 01*

   Incoherent diffractive production of jets in electron DIS off nuclei at high energy

   Benjamin Rodriguez-Aguilar🇮🇹 · D.N. Triantafyllopoulos🇮🇹 · S.Y. Wei🇨🇳

   We study incoherent diffractive production of two and three jets in electron-nucleus deep inelastic scattering (DIS) at small $x_{\mathrm{Bj}}$ using the color dipole picture and the effective theory of the Color Glass Condensate (CGC). We consider color fluctuations in the CGC weight-function as the source of the nuclear break-up and the associated momentum transfer $\sqrt{|t|}$. We focus on the regime in which the two jets are almost back-to-back in transverse space and have transverse momenta $P_{\perp }$ much larger than both the momentum transfer and the saturation scale $Q_s$. The cross section for producing such a hard dijet is parametrically dominated by large size fluctuations in the projectile wave-function that scatter strongly and for which a third, semi-hard, jet appears in the final state. The 2 + 1 jets cross section can be written in a factorized form in terms of incoherent quark and gluon diffractive transverse momentum distributions (DTMDs) when the third jet is explicit, or incoherent diffractive parton distribution functions (DPDFs) when the third jet is integrated over. We find that the DPDFs and the corresponding cross section saturate logarithmically when $|t|\ll Q_s^2$, while they fall like $1/|t{|}^2$ in the regime $Q_s^2\ll |t|\ll P_{\perp }^2$. We further show that there is no angular correlation between the hard jet momentum and the momentum transfer. For typical EIC kinematics the 2 jets and 2 + 1 jets cross sections are of the same order.

   hep-phnucl-thPRD(2024)·7 citations
2. 02*

   Net-proton fluctuations influenced by baryon stopping and quark deconfinement

   Oleh Savchuk🇺🇸

   Preliminary data from the Beam-Energy Scan II measurements by the STAR Collaboration at the Relativistic Heavy Ion Collider suggest a dip in the fourth-to-second-order cumulant ratio when plotted vs. beam energy. At the same energy range where the structure appears, a transition from hadrons to quarks is expected, the deconfinement transition. In this paper, the role of quark deconfinement in establishing fluctuaitions in the early stages of the collision is considered. Two models are compared: one with stopping occurring on a baryon-by-baryon basis, and a second where stopping proceeds through quark degrees of freedom. In the latter model, the fluctuation of baryon number is significantly reduced and this signal is found to survive recombination into hadrons and the subsequent diffusion. The transformation from baryon to quark stopping thus produces a dip in the fourth-to-second-order cumulant ratio when plotted vs. beam energy, consistent with observations.

   hep-phnucl-thPRC(2025)·6 citations
3. 03*

   Walking-dilaton hybrid inflation with $B-L$ Higgs embedded in dynamical scalegenesis

   Jie Liu🇨🇳 · He-Xu Zhang🇨🇳 · Hiroyuki Ishida🇯🇵 · Shinya Matsuzaki🇨🇳

   We propose a hybrid inflationary scenario based on eight-flavor hidden QCD with the hidden colored fermions being in part gauged under $U(1{)}_{B-L}$. This hidden QCD is almost scale-invariant, so-called walking, and predicts the light scalar meson (the walking dilaton) associated with the spontaneous scale breaking, which develops the Coleman-Weinberg (CW) type potential as the consequence of the nonperturbative scale anomaly, hence plays the role of an inflaton of the small-field inflation. The $U(1{)}_{B-L}$ Higgs is coupled to the walking dilaton inflaton, which is dynamically induced from the so-called bosonic seesaw mechanism. We explore the hybrid inflation system involving the walking dilaton inflaton and the $U(1{)}_{B-L}$ Higgs as a waterfall field. We find that observed inflation parameters tightly constrain the $U(1{)}_{B-L}$ breaking scale as well as the walking dynamical scale to be $\sim 10^9$ GeV and $\sim 10^{14}$ GeV, respectively, so as to make the waterfall mechanism worked. The lightest walking pion mass is then predicted to be around 500 GeV. Phenomenological perspectives including embedding of the dynamical electroweak scalegenesis and possible impacts on the thermal leptogenesis are also addressed.

   hep-phJHEP(2024)·4 citations
4. 04*

   Production of $\psi (4040)$, $\psi (4160)$, and $\psi (4415)$ mesons in strong interactions

   Sheng-Nan Xu🇨🇳 · Xiao-Ming Xu🇨🇳

   Using the inelastic scattering of charmed strange mesons by open-charm mesons in hadronic matter produced in Pb-Pb collisions at the Large Hadron Collider, we study the production of $\psi (4040)$, $\psi (4160)$, and $\psi (4415)$ mesons. Master rate equations are established for inelastic scattering. The scattering is caused by quark interchange in association with color interactions between all constituent pairs in different mesons. We consider fifty-one reactions between charmed strange and open-charm mesons. Unpolarized cross sections for the reactions are obtained from a temperature-dependent interquark potential. The temperature dependence of the cross sections causes the contributions of the reactions to the production of $\psi (4040)$, $\psi (4160)$, and $\psi (4415)$ to change with decreasing temperature during the evolution of hadronic matter. For central Pb-Pb collisions at $\sqrt{s_{NN}}=5.02$ TeV, the master rate equations reveal that the $\psi (4040)$ number density is larger than the $\psi (4160)$ number density which is larger than the $\psi (4415)$ number density.

   hep-phhep-exCPC(2025)·0 citations
5. 05*

   Effects of Final State Interactions on Landau Singularities

   Ajay S. Sakthivasan🇩🇪 · Maxim Mai🇺🇸 · Akaki Rusetsky🇩🇪 · Michael Döring🇺🇸

   In certain kinematic and particle mass configurations, triangle singularities may lead to line-shapes which mimic the effects of resonances. This well-known effect is scrutinized here in the presence of final-state rescattering. The goal is achieved first by utilizing general arguments provided by Landau equations, and second by applying a modern scattering formalism with explicit two- and three-body unitarity.

   hep-phhep-exhep-latnucl-thJHEP(2024)·16 citations
6. 06*

   Nf-contribution to the virtual correction for electroweak vector boson production at NNLO

   Dario Kermanschah🇩🇪 · Matilde Vicini🇨🇭

   Multi-loop scattering amplitudes are difficult to evaluate due to singularities of the integrals involved, especially with increasing number of loops, external legs, and mass scales. For the first time for hadronic collisions at two loops, we enable the combined numerical integration over loop momentum and phase space by tackling infrared, ultraviolet and threshold singularities simultaneously using local subtractions. We demonstrate the feasibility of our approach by calculating previously unknown perturbative corrections for processes of interest to the Large Hadron Collider, namely the Nf-part of the finite remainder of the phase-space integrated virtual corrections at next-to-next-to-leading order (NNLO) in QCD for the production of up to three massive electroweak vector bosons in proton-proton collisions.

   hep-phJHEP(2025)·18 citations
7. 07*

   On-shell effective field theory and quantum transport for hard photons

   Marc Comadran🇪🇸 · Cristina Manuel🇪🇸

   We develop an effective field theory for the description of high energetic or hard photons, the on-shell effective theory (OSEFT). The OSEFT describes the so called eikonal or semi-classical optical limit, allowing for corrections organized in a systematic expansion on inverse powers of the photon energy. We derive the OSEFT from the Maxwell Lagrangian, and study its different properties, such as the gauge symmetry and reparametrization invariance. The theory can be finally formulated in terms of a gauge invariant vector gauge field, without the need to introduce gauge-fixing. We then use the OSEFT to compute corrections to the Wigner photon function, and derive its associated side jump effect from reparametrization invariance. Finally, we discuss how to properly define the Stokes parameters from transport theory once quantum effects are considered, so as to preserve their well-defined properties under Lorentz transformations.

   hep-phPRD(2024)·3 citations
8. 08*

   Twist corrections to exclusive vector meson production in a saturation framework

   Renaud Boussarie🇫🇷 · Michael Fucilla🇫🇷 · Lech Szymanowski🇵🇱 · Samuel Wallon🇫🇷

   We develop a framework combining the higher-twist formalism of exclusive processes in the $s$ channel with the semi-classical effective description of small-$x$ physics in the $t$ channel. We apply it to transversely polarized light vector meson production, ${\gamma }^{\ast }p\to V(\rho ,\phi ,\omega )p$, which starts at the next-to-leading power and for which a purely collinear treatment leads to end-point singularities. The result is obtained in the most general kinematics, including both forward and non-forward cases by preserving the full impact parameter dependence in the non-perturbative correlators, in both momentum and coordinate space representations. A systematic expansion of the Wilson lines in terms of Reggeized gluon fields is performed in order to obtain the results in the weak-field BFKL approximation. These new results will allow for investigating the dilute-to-dense regime transition of QCD for a wide class of observables.

   hep-phhep-thPRD(2025)·13 citations
9. 09*

   Axionless strong CP problem solution: the spontaneous CP violation case

   Rodolfo Ferro-Hernandez🇩🇪 · Stefano Morisi🇮🇹 · Eduardo Peinado🇲🇽

   We propose an alternative to the axion mechanism for addressing the charge parity (CP) problem in quantum chromodynamics (QCD). Our approach involves imposing CP as an inherent symmetry of the Lagrangian, which is then spontaneously broken. To generate the correct texture for the Yukawa matrices, we introduce a discrete ${\mathbb{Z}}_2$ symmetry that is softly broken by the scalar potential. By identifying a benchmark point for the Yukawa couplings that aligns with the measured quark masses, the CKM matrix, and low-energy flavor-changing constraints, our findings suggest that this model offers a viable solution to the CP problem.

   hep-phPRD(2025)·7 citations
10. 10*

    On the two-loop BSM corrections to $h⟶\gamma \gamma$ in a triplet extension of the SM

    Giuseppe Degrassi🇮🇹 · Pietro Slavich🇫🇷

    We compute the two-loop BSM contributions to the $h⟶\gamma \gamma$ decay width in the SM extended with a real triplet of $SU(2)$. We consider scenarios in which the neutral components of doublet and triplet do not mix, so that the lighter neutral scalar $h$ has (at least approximately) SM-like couplings to fermions and gauge bosons. We focus on the two-loop corrections controlled by the quartic scalar couplings, and obtain explicit and compact formulas for the $h\gamma \gamma$ amplitude by means of a low-energy theorem that connects it to the derivative of the photon self-energy w.r.t. the Higgs field. We briefly discuss the numerical impact of the newly-computed contributions, showing that they may be required for a precise determination of $\Gamma [h\to \gamma \gamma ]$ in scenarios where the quartic scalar couplings are large.

    hep-phEPJC(2025)·6 citations
11. 11*

    Thermal pressure on ultrarelativistic bubbles from a semiclassical formalism

    Andrew J. Long🇺🇸 · Jessica Turner🇬🇧

    We study a planar bubble wall that is traveling at an ultrarelativistic speed through a thermal plasma. This situation may arise during a first-order electroweak phase transition in the early universe. As particles cross the wall, it is assumed that their mass grows from $m_a$ to $m_b$, and they are decelerated causing them to emit massless radiation ($m_c=0$). We are interested in the momentum transfer to the wall, the thermal pressure felt by the wall, and the resultant terminal velocity of the wall. We employ the semiclassical current radiation (SCR) formalism to perform these calculations. An incident-charged particle is treated as a point-like classical electromagnetic current, and the spectrum of quantum electromagnetic radiation (photons) is derived by calculating appropriate matrix elements. To understand how the spectrum depends on the thickness of the wall, we explore simplified models for the current corresponding to an abrupt and a gradual deceleration. For the model of abrupt deceleration, we find that the SCR formalism can reproduce the $P_{\mathrm{therm}}\propto {\gamma }_w^0$ scaling found in earlier work by assuming that the emission is soft, but if the emission is not soft the SCR formalism can be used to obtain $P_{\mathrm{therm}}\propto {\gamma }_w^2$ instead. For the model of gradual deceleration, we find that the wall thickness $L_w$ enters to cutoff the otherwise log-flat radiation spectrum above a momentum of $\sim {\gamma }_w^2/L_w$, and we discuss the connections with classical electromagnetic bremsstrahlung.

    hep-phastro-ph.COJCAP(2024)·22 citations
12. 12*

    Probing gluonic saturation in deeply virtual meson production beyond leading power

    Renaud Boussarie🇫🇷 · Michael Fucilla🇫🇷 · Lech Szymanowski🇵🇱 · Samuel Wallon🇫🇷

    Exclusive diffractive meson production represents a golden channel for investigating gluonic saturation inside nucleons and nuclei. In this letter, we settle a systematic framework to deal with beyond leading power corrections at small-$x$, including the saturation regime, and obtain the ${\gamma }^{\ast }\to M(\rho ,\varphi ,\omega )$ impact factor with both incoming photon and outgoing meson carrying arbitrary polarizations. This is of particular interest since the saturation scale at modern colliders, although entering a perturbative regime, is not large enough to prevents higher-twist effects to be sizable.

    hep-phhep-exhep-thPRL(2025)·13 citations
13. 13*

    Confronting a Standard Model extension with a dark $U(1)$ gauge sector with the prediction for the W-boson mass

    Stefan Dittmaier🇩🇪 · Jonas Rehberg🇩🇪 · Heidi Rzehak🇩🇪

    The Dark Abelian Sector Model (DASM) is an extension of the Standard Model of particle physics with an additional spontaneously broken $U_{\text{d}}(1)$ gauge symmetry connected to a dark sector, i.e. the SM particles do not carry the corresponding charge. In addition to the gauge boson resulting from the extra $U_{\text{d}}(1)$ gauge symmetry, the particle content is extended by a further Higgs boson, one Dirac fermion as well as right-handed neutrinos. Employing the $U_Y(1)$ field-strength tensor as well as the SM Higgs mass operator (the only two singlet operators of the SM with dimension less than four) and the right-handed neutrino fields, we open three portals to the dark sector. After an introduction of the model, we discuss a renormalization scheme for the complete model with a special focus on the renormalization of the mixing angles. Finally, as an example of application, we present the prediction for the W-boson mass derived from muon decay in the DASM.

    hep-phPoS(2024)·0 citations
14. 14*

    Regge trajectories for the triply heavy bottom-charm baryons in the diquark picture

    Jia-Qi Xie🇨🇳 · He Song🇨🇳 · Jiao-Kai Chen🇨🇳

    We present the explicit form of the Regge trajectory relations for the triply heavy bottom-charm baryons, which can be applied to investigate both the $\lambda$-mode excited states and the $\rho$-mode excited states. We estimate the masses of the $\lambda$-excited states and the $\rho$-excited states. The results are in agreement with other theoretical predictions. Both the $\lambda$-trajectories and the $\rho$-trajectories are discussed. Moreover, the behaviors of the $\lambda$- and $\rho$-trajectories for various baryons are discussed. It is shown that both the $\lambda$-trajectories and the $\rho$-trajectories for baryons are concave downwards in the $(M^2,x)$ plane. The Regge trajectories for the light baryons are approximately linear and become concave as the masses of the light constituents are considered.

    hep-phEPJC(2024)·17 citations
15. 15*

    A complete study of RGE induced leptogenesis in flavor symmetry scenarios

    Zhen-hua Zhao🇨🇳 · Xiang-Yi Wu🇨🇳 · Jing Zhang🇨🇳

    In the literature, motivated by the observed peculiar neutrino mixing pattern and a preliminary experimental hint for maximal Dirac CP phase (i.e., $\delta \sim 3\pi /2$), a lot of flavor and CP symmetries have been proposed to help us understand and explain these experimental results. However, for some flavor-symmetry scenarios (see section~3.1), the leptogenesis mechanism is prohibited to work as usual. To tackle this problem, in this paper we have made an exhausitive study on the possibility that the renormalization group evolution effect may induce a successful leptogenesis for these particular scenarios. Our study provides some complementarities to the previous related studies in Refs. [26, 27, 28] (see section~3.2).

    hep-phPRD(2024)·3 citations
16. 16*

    Collider and astrophysical signatures of light scalars with enhanced $\tau$ couplings

    Jorge Alda🇮🇹 · Gabriele Levati🇮🇹 · Paride Paradisi🇮🇹 · Stefano Rigolin🇮🇹 · Nudzeim Selimovic🇮🇹

    Beyond Standard Model scenarios addressing the flavor puzzle and the hierarchy problem generally predict dominant new physics couplings with fermions of the third generation. In this Letter, we explore the collider and astrophysical signatures of new light scalar and pseudoscalar particles dominantly coupled to the $\tau$-lepton. The best experimental prospects are expected at Belle II through the $e^{+}{e}^{-}\to {\tau }^{+}{\tau }^{-}\gamma \gamma$, ${\tau }^{+}{\tau }^{-}\gamma$, $3\gamma$, mono-$\gamma$ processes, and the $\tau$ anomalous magnetic moment. The correlated effects in these searches can unambiguously point toward the underlying new physics dynamics. Moreover, we study astrophysics bounds - especially from core-collapse supernovae and neutron star mergers - finding them particularly effective and complementary to collider bounds. We carry out this program in the well-motivated context of axion-like particles as well as generic CP-even and CP-odd particles, highlighting possible ways to discriminate among them.

    hep-phhep-exJHEP(2025)·29 citations
17. 17*

    Complete Gravitational-Wave Spectrum of the Sun

    Camilo García-Cely🇪🇸 · Andreas Ringwald🇩🇪

    The high-temperature plasma in the solar interior generates stochastic gravitational waves (GWs). Due to its significance as the primary source of high-frequency GWs in the solar system, we reexamine this phenomenon highlighting some physical processes, including the contribution of macroscopic hydrodynamic fluctuations. Our analysis builds upon several studies of axion emission from the Sun, particularly in relation to the treatment of plasma effects. The resulting GW spectrum is comparable to many well-motivated early Universe signals, yet orders of magnitude below the current sensitivities of axion helioscopes such as (Baby)IAXO.

    hep-phPRL(2025)·18 citations
18. 18*

    Tetraquarks at large $M$ and large $N$

    Héloïse Allaman🇨🇭 · Majid Ekhterachian🇨🇭 · Filippo Nardi🇨🇭 · Riccardo Rattazzi🇨🇭 · Stefan Stelzl🇨🇭

    We study tetraquarks in large $N$ QCD with heavy quarks, in the domain where non-relativistic quantum mechanics offers an adequate approximation. Within the regime of validity of the Born-Oppenheimer approximation, we systematically study and explicitly construct tetraquark states. At leading order in the $1/N$ expansion, the bound spectrum consists of free mesons, while the $1/N$ corrections give rise to a Born-Oppenheimer potential that can bind the mesons into tetraquarks. We find two different types of tetraquarks, each endowed with distinct color-spatial wavefunctions. These states arise in the presence of an $\mathcal{O}(N)$ mass hierarchy between the quarks and the antiquarks. We provide a quantitative argument indicating that only for such a hierarchy is the ground state of the system a tetraquark. We discuss what the extrapolation of our results to realistic values of the parameters may imply for the QCD tetraquark states.

    hep-phhep-thnucl-thJHEP(2024)·7 citations
19. 19*

    Do neutrinos bend? Consequences of an ultralight gauge field as dark matter

    Luca Visinelli🇨🇳 · Tsutomu T. Yanagida🇯🇵 · Michael Zantedeschi🇨🇳

    An ultralight gauge boson could address the missing cosmic dark matter, with its transverse modes contributing to a relevant component of the galactic halo today. We show that, in the presence of a coupling between the gauge boson and neutrinos, these transverse modes affect the propagation of neutrinos in the galactic core. Neutrinos emitted from galactic or extra-galactic supernovae could be delayed by $\delta t=\left(10^{-8}-10^1\right)$s for the gauge boson masses $m_{A^{\prime }}=\left(10^{-23}-10^{-19}\right)$eV and the coupling with the neutrino $g=10^{-27}-10^{-20}$. While we do not focus on a specific formation mechanism for the gauge boson as the dark matter in the early Universe, we comment on some possible realizations. We discuss model-dependent current bounds on the gauge coupling from fifth-force experiments, as well as future explorations involving supernovae neutrinos. We consider the concrete case of the DUNE facility, where the coupling can be tested down to $g\simeq 10^{-27}$ for neutrinos coming from a supernova event at a distance $d=10$kpc from Earth.

    hep-phastro-ph.COastro-ph.GAastro-ph.HE+1Phys.Dark Univ.(2024)·8 citations
20. 20*

    Searching for String Bosenovas with Gravitational Wave Detectors

    Dawid Brzeminski🇺🇸 · Anson Hook🇺🇸 · Junwu Huang🇨🇦 · Clayton Ristow🇺🇸

    We study the phenomenology of string bosenova explosions in vector superradiance clouds around spinning black holes, focusing on the observable consequences in gravitational wave detectors and accelerometers. During the growth of the superradiance cloud, the dark gauge field might reach a critical field strength, when a network of dark photon strings is produced via a superheated phase transition. These dark photon strings will then absorb the energy in the background fields and get ejected from the cloud, with total energy as large as the rotational energy of the black hole. In this paper, we study the subsequent evolution of this dense string network, and the resulting observational consequences depending on the unknown string tension, or almost equivalently, the ratio between the quartic and the gauge coupling in the Abelian Higgs model. Strings with large tension will dissipate into gravitational waves, detectable over a wide range of frequencies, from $\sim$ nHz near supermassive black holes, to $\gtrsim 10$ MHz around stellar mass black holes. This is the first known source of high frequency gravitational waves, unconstrained by cosmological observations. The strain of this gravitational wave can be larger than $10^{-14}$ at low frequencies, lasting for longer than typical duration of experiments. Small tension strings, with total lengths in the network as large as $10^{40}$ km, can travel to the earth with appreciable rate from any black hole in the Milky Way and interact with earth based accelerometers. If the Standard Model particles are directly charged under the dark photon, e.g. B-L, this interaction leads to an acceleration of Standard Model particles that is independent of the coupling constant. We work out the spectral density of this acceleration, and project that modern accelerometers and equivalence principle tests can be sensitive to the passing of these strings.

    hep-phgr-qcJHEP(2025)·6 citations
21. 21*

    Heavy-flavor mesons in a strong electric field

    Jiayun Xiang🇨🇳 · Gaoqing Cao🇨🇳

    Very strong electromagnetic field can be generated in peripheral relativistic heavy ion collisions. This work is devoted to exploring the interplay between the effects of a constant external electric field and confining potential on heavy-flavor mesons. As the corresponding vector potential linearly depends on one spatial coordinate for a constant electric field, it might be able to overcome the linear confining potential of QCD and induce deconfinement. To perform analytic calculations and for comparison, one and two dimensional systems are studied together with the realistic three dimensional systems. The one dimensional Schr$\ddot{\text{o}}$dinger equation can be solved analytically with the help of Airy functions, and deconfinement is indeed realized when the electric field is larger than the string tension. Focus on the confining case, the two and three dimensional Schr$\ddot{\text{o}}$dinger equations can be solved analytically in large $r$ limit with the help of elliptic cosine/sine functions, and the wave functions are dominated by the region antiparallel to the electric field. When a more realistic potential is applied, a non-monotonic feature is found for ${\rm Y}(2S)$ and ${\rm Y}(3S)$-like mesons with increasing electric field.

    ↳ nucl-thhep-phPRD(2024)·2 citations
22. 22*

    Extracting the symmetries of nonequilibrium quantum many-body systems

    Aleksandr N. Mikheev🇩🇪 · Viktoria Noel🇩🇪 · Ido Siovitz🇩🇪 · Helmut Strobel🇩🇪 · Markus K. Oberthaler🇩🇪 · Jürgen Berges🇩🇪

    Symmetries play a pivotal role in our understanding of the properties of quantum many-body systems. While there are theorems and a well-established toolbox for systems in thermal equilibrium, much less is known about the role of symmetries and their connection to dynamics out of equilibrium. This arises due to the direct link between a system's thermal state and its Hamiltonian, which is generally not the case for nonequilibrium dynamics. Here we present a pathway to identify the effective symmetries and to extract them from data in nonequilibrium quantum many-body systems. Our approach is based on exact relations between correlation functions involving different numbers of spatial points, which can be viewed as nonequilibrium versions of (equal-time) Ward identities encoding the symmetries of the system. We derive symmetry witnesses, which are particularly suitable for the analysis of measured or simulated data at different snapshots in time. To demonstrate the potential of the approach, we apply our method to numerical and experimental data for a spinor Bose gas. We investigate the important question of a dynamical restoration of an explicitly broken symmetry of the Hamiltonian by the initial state. Remarkably, it is found that effective symmetry restoration can occur long before the system equilibrates. We also use the approach to define and identify spontaneous symmetry breaking far from equilibrium, which is of great relevance for applications to nonequilibrium phase transitions. Our work opens new avenues for the classification and analysis of quantum as well as classical many-body dynamics in a large variety of systems, ranging from ultracold quantum gases to cosmology.

    ↳ cond-mat.quant-gascond-mat.stat-mechhep-phSciPost Phys.(2025)·3 citations
23. 23*

    Accelerated expansion of the Universe and the Higgs true vacuum

    Muhammad Usman🇵🇰 · Asghar Qadir🇵🇰

    Scalar fields which are favorite among the possible candidates for the dark energy usually have degenerate minima at $\pm {\varphi }_{min}$. In the presented work, we discuss a two Higgs doublet model with the non-degenerate vacuum named inert uplifted double well type two-Higgs doublet model (UDW-2HDM) for the dark energy. It is shown that when the both Higgs doublets lie in their respective true minima then one Higgs doublet can cause the current accelerated expansion of the Universe.

    ↳ gr-qchep-phProceedings of the Fifteenth Marcel Gross…·0 citations
24. 24*

    Probing coalescence of light nuclei via femtoscopy and azimuthal anisotropies

    Yoshini Bailung🇮🇳 · Sudhir Pandurang Rode🇷🇺 · Neha Shah🇮🇳 · Ankhi Roy🇮🇳

    The production mechanism of light nuclei in heavy-ion collisions is vital to understanding the intricate details of nucleon-nucleon interactions. The coalescence of nucleons is a well-known mechanism that attempts to explain the production mechanism of these light clusters. This work investigates the formation mechanism of these nucleon clusters with a combination of coalescence and femtoscopy of nucleons and nuclei. It is achieved by appending a coalescence and correlation afterburner (\texttt{CRAB}) to the \texttt{SMASH} transport model. To have a proper view of the anisotropy of light nuclei clusters, a mean-field approach to \texttt{SMASH} is applied. The anisotropic coefficients of various light nuclei clusters are calculated and compared to experimental measurements. To incorporate hydrodynamics into the picture, the anisotropic measurements are completed in a hybrid \texttt{SMASH}+\texttt{vHLLE} mode. In both approaches, the femtoscopy of nucleons and light nuclei is performed, reported with CRAB, and compared to the latest experimental measurements. An insight into cluster formation time is drawn by extracting the emission source size with the Lednický-Lyuboshits (LL) model.

    ↳ nucl-thhep-phPRC(2025)·2 citations
25. 25*

    Neutrino cosmology after DESI: tightest mass upper limits, preference for the normal ordering, and tension with terrestrial observations

    Jun-Qian Jiang🇨🇳 · William Giarè🇬🇧 · Stefano Gariazzo🇮🇹 · Maria Giovanna Dainotti🇯🇵 · Eleonora Di Valentino🇬🇧 · Olga Mena🇪🇸 · Davide Pedrotti🇮🇹 · Simony Santos da Costa🇮🇹 · Sunny Vagnozzi🇮🇹

    The recent DESI Baryon Acoustic Oscillation measurements have led to tight upper limits on the neutrino mass sum, potentially in tension with oscillation constraints requiring $\sum m_{\nu }\gtrsim 0.06\text{eV}$. Under the physically motivated assumption of positive $\sum m_{\nu }$, we study the extent to which these limits are tightened by adding other available cosmological probes, and robustly quantify the preference for the normal mass ordering over the inverted one, as well as the tension between cosmological and terrestrial data. Combining DESI data with Cosmic Microwave Background measurements and several late-time background probes, the tightest $2\sigma$ limit we find without including a local $H_0$ prior is $\sum m_{\nu }<0.05\text{eV}$. This leads to a strong preference for the normal ordering, with Bayes factor relative to the inverted one of $46.5$. Depending on the dataset combination and tension metric adopted, we quantify the tension between cosmological and terrestrial observations as ranging between $2.5\sigma$ and $5\sigma$. These results are strenghtened when allowing for a time-varying dark energy component with equation of state lying in the physically motivated non-phantom regime, $w(z)\ge -1$, highlighting an interesting synergy between the nature of dark energy and laboratory probes of the mass ordering. If these tensions persist and cannot be attributed to systematics, either or both standard neutrino (particle) physics or the underlying cosmological model will have to be questioned.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2025)·160 citations
26. 26*

    Prospects for Observing High-redshift Radio-loud Quasars in the SKA Era: Paving the Way for 21-cm Forest Observations

    Qi Niu · Yichao Li🇺🇸 · Yidong Xu🇷🇴 · Hong Guo · Xin Zhang🇺🇸

    The 21-cm forest is a sensitive probe for the early heating process and small-scale structures during the epoch of reionization (EoR), to be realized with the upcoming Square Kilometre Array (SKA). Its detection relies on the availability of radio-bright background sources, among which the radio-loud quasars are very promising, but their abundance during the EoR is still poorly constrained due to limited observations. Here, we use a physics-driven model to forecast future radio-loud quasar observations. We fit the parameters of the model using observational data of high-redshift quasars. Assuming Eddington accretion, the model yields an average lifetime of $t_{\mathrm{q}}\sim 10^{5.3}$yr for quasars at $z\sim 6$, consistent with recent results obtained from quasar proximity zone pre-study. We show that if the radio-loud fraction of quasars evolves with redshift, it will significantly reduce the abundance of observable radio-loud quasars in the SKA era, making 21-cm forest studies challenging. With a constant radio-loud fraction, our model suggests that a one-year sky survey conducted with SKA-LOW has the capability to detect approximately 20 radio-loud quasars at $z\sim 9$, with sufficient sensitivity to resolve individual 21-cm forest lines.

    ↳ astro-ph.COgr-qchep-phApJ(2025)·12 citations
27. 27*

    Weyl gauge invariant DBI action in conformal geometry

    D. M. Ghilencea🇷🇴

    We construct the analogue of the Dirac-Born-Infeld (DBI) action in Weyl conformal geometry in $d$ dimensions and obtain a general theory of gravity with Weyl gauge symmetry of dilatations (Weyl-DBI). This is done in the Weyl gauge covariant formulation of conformal geometry in $d$ dimensions, suitable for a gauge theory, in which this geometry is metric. The Weyl-DBI action is a special gauge theory in that it has the same gauge invariant expression with dimensionless couplings in any dimension $d$, with no need for a UV regulator (be it a DR subtraction scale, field or higher derivative operator) for which reason we argue it is Weyl-anomaly free. For $d=4$ dimensions, the leading order of a series expansion of the Weyl-DBI action recovers the gauge invariant Weyl quadratic gravity action associated to this geometry, that is Weyl anomaly-free; this is broken spontaneously and Einstein-Hilbert gravity is recovered in the broken phase, with $\Lambda >0$. All the remaining terms of this series expansion are of non-perturbative nature but can, in principle, be recovered by (perturbative) quantum corrections in Weyl quadratic gravity in $d=4$ in a gauge invariant (geometric) regularisation, provided by the Weyl-DBI action. If the Weyl gauge boson is not dynamical the Weyl-DBI action recovers in the leading order the conformal gravity action. All fields and scales have geometric origin, with no added matter, scalar field compensators or UV regulators.

    ↳ hep-thgr-qchep-phPRD(2025)·9 citations
28. 28*

    Unlocking Discovery Potential for Decaying Dark Matter and Faint X-ray Sources with XRISM

    Yu Zhou🇯🇵 · Volodymyr Takhistov🇯🇵 · Kazuhisa Mitsuda🇯🇵

    Astrophysical emission lines arising from particle decays can offer unique insights into the nature of dark matter (DM). Using dedicated simulations with background and foreground modeling, we comprehensively demonstrate that the recently launched XRISM space telescope with powerful X-ray spectroscopy capabilities is particularly well-suited to probe decaying DM, such as sterile neutrinos and axion-like particles, in the mass range of few to tens of keV. We analyze and map XRISM's DM discovery potential parameter space by considering Milky Way Galactic DM halo, including establishing an optimal line-of-sight search, as well as dwarf galaxies where we identify Segue 1 as a remarkably promising target. We demonstrate that with only 100 ks exposure XRISM/Resolve instrument is capable of probing the underexplored DM parameter window around few keV and testing DM couplings with sensitivity that exceeds by two orders existing Segue 1 limits. Further, we demonstrate that XRISM/Xtend instrument sensitivity enables discovery of the nature of faint astrophysical X-ray sources, especially in Segue 1, which could shed light on star-formation history. We discuss implications for decaying DM searches with improved detector energy resolution in future experiments.

    ↳ astro-ph.HEastro-ph.COastro-ph.GAhep-phApJ(2024)·6 citations
29. 29*

    Determination of the proton spectral function of \isotope[12][]{C} from $(e,e^{\prime }p)$ data

    Artur M. Ankowski🇵🇱 · Omar Benhar🇮🇹 · Makoto Sakuda🇯🇵

    The determination of the nuclear spectral function from the measured cross section of the electron-nucleus scattering process $e+A\to e^{\prime }+p+(A-1)$is discussed, and illustrated for the case of a carbon target. The theoretical model based on the local density approximation, previously employed to derive the spectral function from a combination of accurate theoretical calculations and experimental data, has been developed further by including additional information obtained from measurements performed with high missing energy resolution. The implications for the analysis of $\gamma$-ray emission associated with nuclear deexcitation are considered.

    ↳ nucl-thhep-phPRC(2024)·18 citations
30. 30*

    Recent Developments in Degenerate Higher Order Scalar Tensor Theories

    Andrei Lazanu🇬🇧

    Degenerate Higher Order Scalar Tensor (DHOST) theories are the most general scalar-tensor theories whose Lagrangian depends on the metric tensor and a single scalar field and its derivatives up to second order. They propagate only one scalar degree of freedom, without being plagued by Ostrogradsky instabilities. This is achieved through certain degeneracies of the functions forming their Lagrangian. They generalise the Horndeski and beyond-Horndeski theories. Originally proposed to describe the late-time acceleration of the expansion of the universe, generalising the cosmological constant, they can also be used to build models of the early universe, to describe inflation or alternatives to standard inflation. In the late universe, they modify the standard Vainstein screening mechanism from Horndeski theories (which can have observable consequences) and are suited to build black hole models, featuring non-stealth Kerr black hole solutions. In this work their phenomenology is reviewed, looking at their basic properties, their parameterisations and classifications, focusing on solutions in the early and the late universe and at cosmological and astrophysical constraints.

    ↳ astro-ph.COgr-qchep-phhep-thAnnalen Phys.(2025)·5 citations
31. 31*

    Probing the early universe with future GW observatories

    Suvashis Maity🇮🇳 · Md Riajul Haque🇮🇳

    One of the fundamental characteristics of slow roll inflation is its generation of tensor perturbations, which manifest as stochastic gravitational waves (GWs). Slow roll inflation results in a nearly scale-invariant GW spectrum that maintains its scale invariance as it transitions into the radiation-dominated era. However, introducing an intermediate reheating phase can modify the spectral tilt, depending on the equation of state governing that particular epoch. These GWs, especially on smaller scales, are anticipated to be observable by forthcoming GW detectors. In this study, we initially delineate the parameter space encompassing the inflationary energy scale, reheating temperature, and equation of state in a model-independent manner, focusing on the spectra detectable by GW detectors such as LISA, ET, DECIGO, and BBO. We also examine the implications for the $\alpha$-attractor model of inflation and explore the observational constraints on $n_s-r$ prediction in the light of GW detection. Then, we point out the probable ranges for various non-gravitational and gravitational coupling between the inflaton and Standard Model particles considering the perturbative reheating. If one assumes PBHs were formed during the early reheating era, such detection of GW signal also sheds light on the probing PBH parameters. Note that for the case of PBH domination, we also consider the contribution of the induced GWs due to the density fluctuation in PBH distribution, which helps to decode the phase of early PBH domination. Finally, to test the production of other cosmological relics through future GW missions, we consider dark matter produced via gravitational interaction in the early universe.

    ↳ astro-ph.COhep-phhep-thJCAP(2025)·23 citations
32. 32*

    From 100 kpc to 10 Gpc: Dark Matter self-interactions before and after DESI

    Salvatore Bottaro🇮🇱 · Emanuele Castorina🇮🇹 · Marco Costa🇨🇦 · Diego Redigolo🇮🇹 · Ennio Salvioni🇬🇧

    We consider Dark Matter self-interactions mediated by ultralight scalars. We show that effectively massless mediators lead to an enhancement of the matter power spectrum, while heavier mediators lead to a suppression, together with a feature around their Jeans scale. We derive the strongest present constraints by combining Planck and BOSS data. The recent DESI measurements of Baryon Acoustic Oscillations exhibit a mild $2\sigma$ preference for long-range self-interactions, as strong as $4$ per mille of the gravitational coupling. Full-shape analyses of forthcoming DESI and Euclid data will confirm or disprove such a hint.

    ↳ astro-ph.COhep-phPRD(2025)·32 citations
33. 33*

    On the implications of the `cosmic calibration tension' beyond $H_0$ and the synergy between early- and late-time new physics

    Vivian Poulin🇫🇷 · Tristan L. Smith🇺🇸 · Rodrigo Calderón🇰🇷 · Théo Simon🇫🇷

    The `cosmic calibration tension' is a $>5\sigma$ discrepancy between the cosmological distance ladder built from baryonic acoustic oscillations (BAO) calibrated by the Planck/$\Lambda$CDM sound horizon ($r_s$) and Type Ia supernovae (SN1a) calibrated instead with the S$H_0$ES absolute magnitude, assuming the distance-duality relationship (DDR) holds. In this work, we emphasize the consequences of this tension beyond the value of the Hubble constant $H_0$, and the implications for physics beyond $\Lambda$CDM. Of utmost importance, it implies a larger physical matter density ${\omega }_m\equiv {\Omega }_m{h}^2$, as both the fractional matter density ${\Omega }_m$ and $h\equiv H_0/100$ km/s/Mpc are well constrained from late-time data. New physics in the pre-recombination era must thus be able to decrease $r_s$ while either reducing the value of ${\Omega }_m$, or increasing the value of ${\omega }_m$. Assuming a $\Lambda$CDM-like primordial power spectrum, this necessarily results in an increase in the clustering amplitude ${\sigma }_8$. Deviations from $\Lambda$CDM in the late-time expansion history cannot resolve the calibrator tension but can help relax the required shifts to the matter density and ${\sigma }_8$: it is in that sense that a combination of early and late-time new physics may help alleviate the tension. More precisely, models that modify the pre-recombination expansion history can accommodate the increase in ${\omega }_m$ without the need for additional modifications. It is those models which only affect recombination that require additional deviations at late-times to be successful. Hence, the `cosmic calibration tension' points either to a targeted modification of the pre-recombination expansion history, or to a broader change affecting multiple cosmic epochs.

    ↳ astro-ph.COhep-phPRD(2025)·89 citations
34. 34*

    Travelling-wave, Quasi-periodic, and Longulent States of the Galerkin-regularized Hydrodynamic-type Systems

    Jian-Zhou Zhu

    Travelling-wave, quasi-periodic and ``longulent'' states of the Galerkin-regularized systems preserving finite Fourier modes are exposed. The longulent states are characterized by solitonic structures, called ``longons'', accompanied by disordered components, which is associated to whiskered tori according to the \textit{a-posteriori} Kolmogorov-Arnold-Moser (KAM) theorem. On-torus invariants are introduced for constructing the KAM tori, towards a potential pseudo-integrability theory. Persistence of the longulent states with respect to certain dispersive and dissipative perturbations are also numerically indicated.

    ↳ nlin.PShep-ph0 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.