Wed·Apr 3, 2024Wednesday·April 3, 2024

1. 01*

   Probing Stochastic Ultralight Dark Matter with Space-based Gravitational-Wave Interferometers

   Yue-Hui Yao🇨🇳 · Yong Tang🇨🇳

   Ultralight particles are theoretically well-motivated dark matter candidates. In the vicinity of the solar system, these ultralight particles can be described as a superposition of plane waves, resulting in a stochastic field with sizable amplitude fluctuations on scales determined by the velocity dispersion of dark matter. In this work, we systematically investigate the sensitivity of space-based gravitational-wave interferometers to the stochastic ultralight dark matter (ULDM) field within the frequentist framework. We derive the projected sensitivity of a single detector using the time-delay interferometry. Our results show that space-based gravitational-wave interferometers have the potential to probe unconstrained regions in parameter space and improve the current limit on coupling strengths. Furthermore, we explore the sensitivity of a detector network and investigate the optimal configuration for ULDM detection. We introduce the overlap reduction function for ULDM, which quantifies the degree of correlation between the signals observed by different detectors. We find that the configuration, where the signals observed by two detectors are uncorrelated, is the optimal choice for ULDM detection due to a smaller chance of missing signal. This contrasts with the detection of stochastic gravitational-wave background, where the correlated configuration is preferred. Our results may provide useful insights for potential joint observations involving space-based gravitational-wave detectors like LISA and Taiji, as well as other ULDM detection networks operating in the coherence limit.

   hep-phastro-ph.COgr-qcPRD(2024)·17 citations
2. 02*

   Doubly heavy hadrons production in ultraperipheral collision

   Hao Yang🇨🇳 · Jun Jiang🇨🇳 · Bingwei Long🇨🇳

   We study the double heavy baryon ${\Xi }_{Q{Q}^{\prime }}$ and tetraquark $T_{QQ}$ production through photon-photon and photon-gluon fusion via ultraperipheral collisions at the LHC and FCC within the framework of nonrelativistic QCD factorization formalism. Various ion-ion collisions are taken into account, two cc(bb)-diquark configurations ($[cc(bb),{}^3{S}_1\text{mbox}-\bar{3}]$ and $[cc(bb),{}^1{S}_0\text{mbox}-6]$) and four bc-diquark configurations ($[bc,{}^3{S}_1\text{mbox}-\bar{3}]$, $[bc,{}^3{S}_1\text{mbox}-6]$, $[bc,{}^1{S}_0\text{mbox}-\bar{3}]$ and $[bc,{}^1{S}_0\text{mbox}-6]$) are considered in the calculation. Numerical results indicate that the $[cc,{}^3{S}_1\text{mbox}-\bar{3}]$ diquark provides dominant contribution for ${\Xi }_{cc}$ ($T_{cc}$) production, and a considerable number of ${\Xi }_{cc}$ ($T_{cc}$) can be produced. Due to the event topologies for ultraperipheral collision are very clear, the background from various QCD interactions can be suppressed, hence the experimental investigation for ${\Xi }_{cc}$ and $T_{cc}$ are feasible. The productions for ${\Xi }_{bc/bb}$ are also discussed, leaving only slightly possibility for ${\Xi }_{bc}$ through photon-gluon fusion with ultraperipheral collisions at the FCC.

   hep-phPRD(2024)·7 citations
3. 03*

   The resonance effect for the CP asymmetry associated with the process $\omega \to {\pi }^{+}{\pi }^{-}{\pi }^0$

   Xi-Liang Yuan · Gang Lü

   The direct CP asymmetry in the weak decay process of hadrons is commonly attributed to the weak phase of the CKM matrix and the indeterminate strong phase. We propose a way of creating a strong phase difference between two decay paths involving vector mesons $V=\omega ,\rho$ decaying to ${\pi }^{+}{\pi }^{-}{\pi }^0$ considering the G-parity suppressed decay process ${\rho }^0\to {\pi }^{+}{\pi }^{-}{\pi }^0$. It can lead to a significant CP asymmetry in the interference region. We consider the effects of $\omega$ and $\rho$ mixing on their decays to ${\pi }^{+}{\pi }^{-}{\pi }^0$. Meanwhile, we calculate the CP asymmetry for the process $B\to {\pi }^{+}{\pi }^{-}{\pi }^{0}P$ (P refers to pseudoscalar meson) through $\omega (\rho )\to {\pi }^{+}{\pi }^{-}{\pi }^0$. Besides, we also calculate the integral results of different phase space regions. We hope that our work can help provide some theoretical guidance for future experimental studies of CP asymmetry in these decays.

   hep-phCPC(2025)·2 citations
4. 04*

   Semileptonic $W$ Decay to the $B$ Meson with Lepton Pairs in Heavy Quark Effective Theory Factorization upto $\mathcal{O}$$({\alpha }_s)$

   Saadi Ishaq🇵🇰 · Sajawal Zafar🇵🇰 · Abdur Rehman🇨🇦 · Ishtiaq Ahmed🇵🇰

   Motivated by the study of heavy-light meson production within the framework of heavy quark effective theory (HQET) factorization, we extend the factorization formalism for a rather complicated process $W^{+}\to B^{+}{\ell }^{+}{\ell }^{-}$ in the limit of a non-zero invariant squared-mass of dilepton, $q^2$, at the lowest order in $1/m_b$ up to $\mathcal{O}({\alpha }_s)$. The purpose of the current study is to extend the HQET factorization formula for the $W^{+}\to B^{+}{\ell }^{+}{\ell }^{-}$ process and subsequently compute the form factors for this channel up to next-to-leading-order corrections in ${\alpha }_s$. We explicitly show the amplitude of the $W^{+}\to B^{+}{\ell }^{+}{\ell }^{-}$ process can also be factorized into a convolution between the perturbatively calculable hard-scattering kernel and the non-perturbative yet universal light-cone distribution amplitude (LCDA) defined in HQET. The validity of HQET factorization depends on the assumed scale hierarchy $m_W\sim m_b\gg {\Lambda }_{\mathrm{QCD}}$. Within the HQET framework, we evaluate the form factors associated with the $W^{+}\to B^{+}{\ell }^{+}{\ell }^{-}$ process, providing insights into its phenomenology. In addition, we also perform an exploratory phenomenological study on $W^{+}\to B^{+}{\ell }^{+}{\ell }^{-}$ by employing an exponential model for the LCDAs for $B^{+}$ meson. Our findings reveal that the branching ratio for $W^{+}\to B^{+}{\ell }^{+}{\ell }^{-}$ is below $10^{-10}$. Although the branching ratios are small, this channel in high luminosity LHC experiments may serve to further constraints the value of ${\lambda }_B$.

   hep-phPTEP(2024)·2 citations
5. 05*

   Bjorken sum rule with analytic coupling

   I.R. Gabdrakhmanov🇷🇺 · N.A Gramotkov🇷🇺 · A.V. Kotikov🇷🇺 · O.V. Teryaev🇷🇺 · D.A. Volkova🇷🇺 · I.A. Zemlyakov🇨🇱

   We found good agreement between the experimental data obtained for the polarized Bjorken sum rule and the predictions of analytic QCD, as well as a strong difference between these data and the results obtained in the framework of perturbative QCD. To satisfy the limit of photoproduction and take into account Gerasimov-Drell-Hearn and Burkhardt-Cottingham sum rules, we develope new representation of the perturbative part of the polarized Bjorken sum rule.

   hep-phInt.J.Mod.Phys.A(2025)·12 citations
6. 06*

   Electric corrections to $\pi$-$\pi$ scattering lenghts in the linear sigma model

   R. Cadiz🇨🇱 · M. Loewe🇨🇱 · R. Zamora🇨🇱

   In this article we analyze the role of an external electric field, in the weak field approximation, on $\pi$-$\pi$ scattering lengths. The discussion is presented in the frame of the linear sigma model. To achieve this, we take into account all one-loop corrections in the $s$, $t$, and $u$ channels associated with the insertion of a Schwinger propagator for charged pions, focusing on the region characterized by small values of the electric field. Furthermore, one of the novelties of our work is the explicit calculation of box diagrams, which were previously overlooked in discussions regarding magnetic corrections. It turns out that the electric field corrections have an opposite effect with respect to magnetic corrections calculated previously in the literature.

   hep-phhep-thPRD(2024)·4 citations
7. 07*

   Hydrodynamics as sound-speed approaches light-speed

   Guy D. Moore🇩🇪

   I present the simplest 3+1 dimensional quantum field theory for which the speed of sound can be arbitrarily close to the speed of light. Examining the hydrodynamics, I find cases where the shear viscosity is finite, but the "shear relaxation coefficient" appears always to be divergently large.

   hep-phJHEP(2024)·3 citations
8. 08*

   Computable conditions for order-2 $CP$ symmetry in NHDM potentials

   R. Plantey🇳🇴 · M. Aa. Solberg🇳🇴

   We derive necessary and sufficient conditions for order-2 $CP$ ($CP2$) symmetry in $N$-Higgs-doublet potentials for $N>2$. The conditions, which are formulated as relations between vectors that transform under the adjoint representation of $\mathsf{SU}(N)$ under a change of doublet basis, are representation theoretical in nature. Making use of Lie algebra and representation theory we devise an efficient, computable algorithm which may be applied to decide whether or not a given numerical potential is $CP2$ invariant.

   hep-phhep-thmath-phmath.MPJHEP(2024)·3 citations
9. 09*

   High-energy neutrinos flavour composition as a probe of neutrino magnetic moments

   Artem Popov🇷🇺 · Alexander Studenikin🇷🇺

   Neutrino propagation in the Galactic and extragalactic magnetic fields is considered. We extend an approach developed in \cite{Popov:2019nkr} to describe neutrino flavour and spin oscillations using wave packets. The evolution equations for the neutrino wave packets in a uniform and non-uniform magnetic fields are derived. The analytical expressions for neutrino flavour and spin oscillations probabilities accounting for damping due to the wave packet separation are obtained for the case of a uniform magnetic field. It is shown that terms in the flavour oscillations probabilities that depend on the magnetic field strength are characterized by two coherence lengths. One of the coherence lengths coincides with the coherence length for neutrino oscillations in vacuum, while the second one is proportional to the cube of the average neutrino momentum $p_0^3$. The probabilities of flavour and spin oscillations are calculated numerically for neutrino interacting with the non-uniform Galactic magnetic field. It is shown that oscillations on certain frequencies are suppressed on the Galactic scale due to the neutrino wave packets separation. The flavour compositions of high-energy neutrino flux coming from the Galactic centre and ultra-high energy neutrinos from an extragalactic sourse are calculated accounting for neutrino interaction with the magnetic field and decoherence due to the wave packet separation. It is shown that for neutrino magnetic moments $\sim 10^{-13}{\mu }_B$ and larger these flavour compositions significantly differ from ones predicted by the vacuum neutrino oscillations scenario.

   hep-phhep-thPRD(2025)·6 citations
10. 10*

    Dynamical study of $D^{\ast }DK$ and $D^{\ast }D\bar{D}$ systems at quark level

    Yue Tan🇨🇳 · Xuejie Liu🇨🇳 · Xiaoyun Chen🇨🇳 · Youchang Yang🇨🇳 · Hongxia Huang🇨🇳 · Jialun Ping🇨🇳

    Inspired by that Belle\uppercase\expandafter{\romannumeral2} Collaboration recently reported $T_{cc}$, which can be interpreted as a molecular $D{D}^{\ast }$, we investigated the trihadron system of $T_{cc}$ partner with $I{J}^P$=$01^{-}$ in the framework of a chiral quark model. It's widely accepted that the main component of $X(3872)$ contains the molecular $\bar{D}{D}^{\ast }$, while the main component of $D_{s0}^{\ast }(2317)$ is molecular $DK$. Based on these three well-known exotic states, $T_{cc}(D{D}^{\ast })$, $X(3872)(\bar{D}{D}^{\ast })$ and $D_{s0}^{\ast }(2317)(DK)$, we dynamically investigate $D^{\ast }DK$ and $D{D}^{\ast }\bar{D}$ systems at quark level to search for possible bound states. The results show that both of them are bound states, in which the binding energy of the molecular state $D{D}^{\ast }K$ is relatively small, only 0.8 MeV, while the binding energy of $D{D}^{\ast }\bar{D}$ is up to 1.9 MeV. According to the calculation results of the Root-square-mean distances, the spatial structure of the two systems shows obvious ($D{D}^{\ast }$)-($\bar{D}$/$K$) structure, in which $D$ is close to $D^{\ast }$ while $D{D}^{\ast }$ as a whole is relatively distant from the third hadron ($\bar{D}$/$K$), which are similar to the nucleon-electron structure. As a result, we strongly recommend that these bound states $D{D}^{\ast }\bar{D}$ and $D{D}^{\ast }K$ are searched for experimentally.

    hep-phPRD(2024)·11 citations
11. 11*

    On the model uncertainties for the predicted muon content of extensive air showers

    Sergey Ostapchenko🇩🇪 · Günter Sigl🇩🇪

    Motivated by the excess of the muon content of cosmic ray induced extensive air showers (EAS), relative to EAS modeling, observed by the Pierre Auger Observatory, and by the tension between Auger data and air shower simulations on the maximal muon production depth $X_{\max }^{\mu }$, we investigate the possibility to modify the corresponding EAS simulation results, within the Standard Model of particle physics. We start by specifying the kinematic range for secondary hadron production, which is of relevance for such predictions. We further investigate the impact on the predicted EAS muon number and on $X_{\max }^{\mu }$ of various modifications of the treatment of hadronic interactions, in the framework of the QGSJET-III model, in particular the model calibration to accelerator data, the amount of the "glue" in the pion, and the energy dependence of the pion exchange process. None of the considered modifications of the model allowed us to enhance the EAS muon content by more than 10\%. On the other hand, for the maximal muon production depth, some of the studied modifications of particle production give rise up to $\sim 10$ g/cm${}^2$ larger $X_{\max }^{\mu }$ values, which increases the difference with Auger observations.

    hep-phastro-ph.HEAstropart.Phys.(2024)·9 citations
12. 12*

    Coloured spin-1 states in composite Higgs models

    Giacomo Cacciapaglia🇫🇷 · Aldo Deandrea🇫🇷 · Manuel Kunkel🇩🇪 · Werner Porod🇩🇪

    Strong dynamics for composite Higgs models predict spin-1 resonances which are expected to be in the same mass range as the usually considered top-partners. We study here QCD-coloured vector and axial-vector states stemming from composite Higgs dynamics in several relevant models based on an underlying gauge-fermion description. These states can come as triplet, sextet and octet representation. All models considered have a colour octet vector state in common which can be singly produced at hadron colliders as it mixes with the gluon. We explore the rich and testable phenomenology of these coloured spin-1 states at the LHC and future colliders.

    hep-phJHEP(2024)·17 citations
13. 13*

    Probing the Cosmic Neutrino Background and New Physics with TeV-Scale Astrophysical Neutrinos

    Jack Franklin🇬🇧 · Ivan Martinez-Soler🇬🇧 · Yuber F. Perez-Gonzalez🇪🇸 · Jessica Turner🇬🇧

    We use recent evidence of TeV neutrino events from the most significant astrophysical sources detected by IceCube -- NGC 1068, TXS 0506+056, PKS 1424+240 -- to constrain the local and global overdensity of relic neutrinos and to explore potential new neutrino self-interactions. Assuming a relic neutrino overdensity, such high-energy neutrinos have travelled considerable distances through a sea of relic neutrinos and could have undergone scattering, altering their observed flux on Earth. Considering only Standard Model interactions, we constrain the relic overdensity to $\eta \le 2\times 10^{14}$ at the 90$\%$ confidence level, assuming the sum of neutrino masses saturates the cosmological bound, ${\sum }_i{m}_i=0.13$ eV. We demonstrate that this limit improves for larger neutrino masses and study how it depends on the scale of the overdensity region. Considering new interactions between TeV-scale neutrinos and relic neutrinos, mediated by a light boson, we probe couplings of approximately $g\sim 10^{-2}$ with current data for a boson mass around the MeV scale. We demonstrate that this limit improves with larger neutrino masses and the scale of the overdensity region.

    hep-phastro-ph.COastro-ph.HEPLB(2025)·16 citations
14. 14*

    CYG$\nu$S: Detecting solar neutrinos with directional gas time projection chambers

    Chiara Lisotti🇦🇺 · Ciaran A. J. O'Hare🇦🇺 · Elisabetta Baracchini🇮🇹 · Victoria U. Bashu🇦🇺 · Lindsey J. Bignell🇦🇺 · Ferdos Dastgiri🇦🇺 · Majd Ghrear🇺🇸 · Gregory J. Lane🇦🇺 · Lachlan J. McKie🇦🇺 · Peter C. McNamara🇦🇺 · Samuele Torelli🇮🇹

    CYGNUS is a proposed global network of large-scale gas time projection chambers (TPCs) with the capability of directionally detecting nuclear and electron recoils at $\gtrsim$keV energies. The primary focus of CYGNUS so far has been the detection of dark matter, with directional sensitivity providing a means of circumventing the so-called neutrino fog. However, the excellent background rejection and electron/nuclear recoil discrimination provided by directionality could turn the solar neutrino background into an interesting signal in its own right. For example, directionality would facilitate the simultaneous spectroscopy of multiple different flux sources. Here, we evaluate the possibility of measuring solar neutrinos using the same network of gas TPCs built from $10$ m${}^3$-scale modules operating under conditions that enable simultaneous sensitivity to both dark matter and neutrinos. We focus in particular on electron recoils, which provide access to low-energy neutrino fluxes like $pp$, $pep$, ${}^7$Be, and CNO. An appreciable event rate is already detectable in experiments consisting of a single $10$ m${}^3$ module, assuming standard fill gases such as CF${}_4$ mixed with helium at atmospheric pressure. With total volumes around 1000 m${}^3$ or higher, the TPC network could be complementary to dedicated neutrino observatories, whilst entering the dark-matter neutrino fog via the nuclear recoil channel. We evaluate the required directional performance and background conditions to observe, discriminate, and perform spectroscopy on neutrino events. We find that, under reasonable projections for planned technology that will enable 10--30-degree angular resolution and $\sim 10$\% fractional energy resolution, CYGNUS could be a competitive directional neutrino experiment.

    hep-phphysics.ins-detEPJC(2024)·11 citations
15. 15*

    Upcoming searches for decaying dark matter with ULTRASAT ultraviolet maps

    Sarah Libanore🇮🇱 · Ely D. Kovetz🇮🇱

    Decaying dark matter (DDM) can be tested via different astrophysical and cosmological probes. In particular, particles in the $\sim$ 9.5 - 30 eV mass range that decay into monochromatic photons, would contribute to the extragalactic background light (EBL) in the ultraviolet (UV) bandwidth. In this work, we show that an intriguing improvement to the constraints on such DDM models can come from broadband UV surveys, such as GALEX or the upcoming ULTRASAT satellite. These provide diffuse light maps of the UV EBL, integrated over a wide redshift range. The cross correlation between intensity fluctuations in these maps with a reference spectroscopic galaxy survey, can be used to reconstruct the redshift evolution of the EBL intensity; in this way, it is also possible to detect signatures of contributions from DDM. We forecast the constraining power of (GALEX+ULTRASAT)$\times$DESI, and we show they will be able to detect DDM with decay rate up to $\mathcal{O}(10^{-26}\mathrm{s})$. In the context of axion-like particles (ALP), our forecasts can be converted to constraints on the ALP-photon coupling; our results show this technique will test ALP with coupling $\lesssim \mathcal{O}(10^{-12}\mathrm{Ge}{\mathrm{V}}^{-1})$, more than an order of magnitude better than current bounds in this mass range.

    ↳ astro-ph.COhep-phPRD(2025)·7 citations
16. 16*

    Breaking the mass-sheet degeneracy in strong lensing mass modeling with weak lensing observations

    Narayan Khadka🇺🇸 · Simon Birrer🇺🇸 · Alexie Leauthaud🇺🇸 · Holden Nix

    The Hubble constant ($H_0$), a crucial parameter in cosmology, quantifies the expansion rate of the universe so its precise measurement is important to understand the fundamental dynamics of our evolving universe. One of the major limitations of measuring $H_0$ using time-delay cosmography is the presence of the mass-sheet degeneracy (MSD) in the lens mass modeling. We propose and quantitatively assess the use of galaxy-galaxy shear measurements to break the MSD in the strong lensing mass modeling. We use stacked galaxy-galaxy lensing profiles and corresponding covariance matrices from Huang et al. (2022) to constrain the MSD in lens mass modeling with a highly flexible mass profile. Our analyses show that if ideally all galaxy-galaxy lensing measurements from the Hyper Suprime-Cam (HSC) survey can be used to constrain the MSD, we can achieve $\sim 10\%$ precision on the MSD constraint. We forecast that galaxy-galaxy lensing measurements from LSST-like surveys can in general constrain the MSD with $\sim 1-3\%$ precision. Furthermore, if we push weak lensing measurements to a lower angular scale of $\sim 0.04$ $\mathrm{Mpc}$, a survey like LSST can provide $\sim 1\%$ precision on the MSD constraint, enabling a measurement of $H_0$ at the $1\%$ level. We demonstrate that galaxy-galaxy weak lensing can robustly constrain the MSD independent of stellar kinematics of the deflector, with wide-field survey data alone.

    ↳ astro-ph.COgr-qchep-phhep-thMNRAS(2024)·13 citations
17. 17*

    The radiative decay of scalar glueball from lattice QCD

    Jintao Zou🇨🇳 · Long-Cheng Gui🇨🇳 · Ying Chen🇨🇳 · Jian Liang🇨🇳 · Xiangyu Jiang🇨🇳 · Wen Qin🇨🇳 · Yi-Bo Yang🇨🇳

    We perform the first lattice QCD study on the radiative decay of the scalar glueball to the vector meson $\varphi$ in the quenched approximation. The calculations are carried out on three gauge ensembles with different lattice spacings, which enable us to do the continuum extrapolation. We first revisit the radiative $J/\psi$ decay into the scalar glueball $G$ and obtain the partial decay width $\Gamma (J/\psi \to \gamma G)=0.578(86)\text{keV}$ and the branching fraction $\text{Br}(J/\psi \to \gamma G)=6.2(9)\times 10^{-3}$. We then extend the similar calculation to the process $G\to \gamma \varphi$ and get the partial decay width $\Gamma (G\to \gamma \varphi )=0.074(47)\text{keV}$, which implies that the combined branching fraction of $J/\psi \to \gamma G\to \gamma \gamma \varphi$ is as small as $\mathcal{O}(10^{-9})$ such that this process is hardly detected by the BESIII experiment even with the large $J/\psi$ sample of $\mathcal{O}(10^{10})$. With the vector meson dominance model, the two-photon decay width of the scalar glueball is estimated to be $\Gamma (G\to \gamma \gamma )=0.53(46)\text{eV}$, which results in a large stickiness $S(G)\sim \mathcal{O}(10^4)$ of the scalar glueball by assuming the stickiness of $f_2(1270)$ to be one.

    ↳ hep-lathep-exhep-phSCPMA(2024)·6 citations
18. 18*

    Validity of a finite temperature expansion for dense nuclear matter

    Debora Mroczek🇺🇸 · Nanxi Yao🇺🇸 · Katherine Zine🇺🇸 · Jacquelyn Noronha-Hostler🇺🇸 · Liam Brodie🇺🇸 · Veronica Dexheimer🇺🇸 · Alexander Haber🇺🇸 · Elias R. Most🇺🇸

    In this work we provide a new, well-controlled expansion of the equation of state of dense matter from zero to finite temperatures ($T$) while covering a wide range of charge fractions ($Y_Q$), from pure neutron to isospin symmetric nuclear matter. Our expansion can be used to describe neutron star mergers using the equation of state inferred from neutron star observations. We discuss how knowledge from low-energy nuclear experiments and heavy-ion collisions can be directly incorporated into the expansion. We also suggest new thermodynamic quantities of interest that can be calculated from theoretical models or directly inferred by experimental data that can be used to infer the finite temperature equation of state. With our new method, we can quantify the uncertainty in our finite $T$ and $Y_Q$ expansions without making assumptions about the underlying degrees of freedom. We can reproduce results from a microscopic equation of state up to $T=100$ MeV for baryon chemical potential ${\mu }_B\gtrsim 1100$ MeV ($\sim 1-2n_{\mathrm{sat}}$) within $5\%$ error, with even better results for larger ${\mu }_B$ and/or lower $T$. We investigate the sources of numerical and theoretical uncertainty and discuss future directions of study.

    ↳ astro-ph.HEhep-phnucl-thPRC(2026)·21 citations
19. 19*

    A nonperturbative test of nucleation calculations for strong phase transitions

    Oliver Gould🇬🇧 · Anna Kormu🇫🇮 · David J. Weir🇫🇮

    Nucleation rate computations are of broad importance in particle physics and cosmology. Perturbative calculations are often used to compute the nucleation rate $\Gamma$, but these are incomplete. We perform nonperturbative lattice simulations of nucleation in a scalar field theory with a tree-level barrier, computing a final result extrapolated to the thermodynamic and continuum limits. Although the system in question should be well-described by a complete one-loop perturbative calculation, we find only qualitative agreement with the full perturbative result, with a 20% discrepancy in $|\log \Gamma |$. Our result motivates further testing of the current nucleation paradigm.

    ↳ hep-thastro-ph.COhep-lathep-phPRD(2025)·35 citations
20. 20*

    BOSS Constraints on Massive Particles during Inflation: The Cosmological Collider in Action

    Giovanni Cabass🇺🇸 · Oliver H. E. Philcox🇺🇸 · Mikhail M. Ivanov🇺🇸 · Kazuyuki Akitsu🇯🇵 · Shi-Fan Chen🇺🇸 · Marko Simonović🇨🇭 · Matias Zaldarriaga🇺🇸

    Massive particles leave imprints on primordial non-Gaussianity via couplings to the inflaton, even despite their exponential dilution during inflation: practically, the Universe acts as a Cosmological Collider. We present the first dedicated search for spin-zero particles using BOSS redshift-space galaxy power spectrum and bispectrum multipoles, as well as Planck CMB non-Gaussianity data. We demonstrate that some Cosmological Collider models are well approximated by the standard equilateral and orthogonal parametrization; assuming negligible inflaton self-interactions, this facilitates us translating Planck non-Gaussianity constraints into bounds on Collider models. Many models have signatures that are not degenerate with equilateral and orthogonal non-Gaussianity and thus require dedicated searches. Here, we constrain such models using BOSS three-dimensional redshift-space galaxy clustering data, focusing on spin-zero particles in the principal series (i.e. with mass $m\ge 3H/2$) and constraining their couplings to the inflaton at varying speed and mass, marginalizing over the unknown inflaton self-interactions. This is made possible through an improvement in Cosmological Bootstrap techniques and the combination of perturbation theory and halo occupation distribution models for galaxy clustering. Our work sets the standard for inflationary spectroscopy with cosmological observations, providing the ultimate link between physics on the largest and smallest scales.

    ↳ astro-ph.COhep-phhep-thPRD(2025)·86 citations
21. 21*

    Exploring Spin Polarization of Heavy Quarks in Magnetic Fields and Hot Medium

    Zhiwei Liu🇨🇳 · Yunfan Bai🇬🇧 · Shiqi Zheng🇺🇸 · Anping Huang🇨🇳 · Baoyi Chen🇨🇳

    Relativistic heavy-ion collisions give rise to the formation of both deconfined QCD matter and a strong magnetic field. The spin of heavy quarks is influenced by interactions with the external magnetic field as well as by random scatterings with thermal light partons. The presence of QCD matter comprising charged quarks can extend the lifetime and strength of the magnetic field, thereby enhancing the degree of heavy quark polarization. However, the random scatterings with QCD matter tend to diminish heavy quark polarization. In this study, we utilize the Landau-Lifshitz-Gilbert (LLG) equation to investigate both these contributions. Taking into account the realistic evolutions of medium temperatures and the in-medium magnetic fields at the Relativistic Heavy-Ion Collider (RHIC) and the Large Hadron Collider (LHC), we observe that heavy quark polarization is limited by the short lifetime of the magnetic field and the high temperatures of the medium. Furthermore, we explore the mass dependence of quark polarization, revealing that the polarization degree of strange quarks is much larger than that of charm quarks.

    ↳ nucl-thhep-phPRC(2024)·8 citations
22. 22*

    Search for $C$-even states decaying to $D_s^{\pm }{D}_s^{\ast \mp }$ with masses between $4.08$ and $4.32\mathrm{GeV}/c^2$

    BESIII Collaboration: M. Ablikim · M. N. Achasov · P. Adlarson · O. Afedulidis · X. C. Ai · R. Aliberti · A. Amoroso · Q. An · Y. Bai · O. Bakina · I. Balossino · Y. Ban and 650 other authors

    Six $C$-even states, denoted as $X$, with quantum numbers $J^{PC}=0^{-+}$, $1^{\pm +}$, or $2^{\pm +}$, are searched for via the $e^{+}{e}^{-}\to \gamma D_s^{\pm }{D}_s^{\ast \mp }$ process using $(1667.39\pm 8.84){\mathrm{pb}}^{-1}$ of $e^{+}{e}^{-}$ collision data collected with the BESIII detector operating at the BEPCII storage ring at center-of-mass energy of $\sqrt{s}=(4681.92\pm 0.30)\mathrm{MeV}$. No statistically significant signal is observed in the mass range from $4.08$ to $4.32\mathrm{GeV}/c^2$. The upper limits of $\sigma [e^{+}{e}^{-}\to \gamma X]\cdot \mathcal{B}[X\to D_s^{\pm }{D}_s^{\ast \mp }]$ at a $90\%$ confidence level are determined.

    ↳ hep-exhep-phPRD(2024)·4 citations
23. 23*

    Maximal Clauser-Horne-Shimony-Holt violation for qubit-qudit states

    Alexander Bernal🇪🇸 · J. Alberto Casas🇪🇸 · Jesus M. Moreno🇪🇸

    We evaluate the maximal Clauser-Horne-Shimony-Holt (CHSH) violation for a generic (typically mixed) qubit-qudit state, obtaining easily computable expressions in arbitrary qudit dimension. This represents the optimal (2-2-2) Bell nonlocality for this kind of systems. The work generalizes the well-known Horodeckis result for a qubit-qubit setup. We also give simple lower and upper bounds on that violation. We apply our general results to address a number of issues, namely, we obtain a bound on the degree of purity required in a system to exhibit nonlocality and study the statistics of nonlocality in random density matrices. In addition, we show the impossibility of improving the amount of CHSH violation by embedding the qudit in a Hilbert space of larger dimension. Finally, the general result is illustrated with a family of density matrices in the context of a qubit-qutrit system.

    ↳ quant-phhep-phhep-thPRA(2025)·8 citations
24. 24*

    Tightening the reins on non-minimal dark sector physics: Interacting Dark Energy with dynamical and non-dynamical equation of state

    William Giarè🇬🇧 · Yuejia Zhai🇬🇧 · Supriya Pan🇮🇳 · Eleonora Di Valentino🇬🇧 · Rafael C. Nunes🇧🇷 · Carsten van de Bruck🇬🇧

    We present a comprehensive reassessment of the state of Interacting Dark Energy (IDE) cosmology, namely models featuring a non-gravitational interaction between Dark Matter (DM) and Dark Energy (DE). To achieve high generality, we extend the dark sector physics by considering two different scenarios: a non-dynamical DE equation of state $w_0\ne -1$, and a dynamical $w(a)=w_0+w_a(1-a)$. In both cases, we distinguish two different physical regimes resulting from a phantom or quintessence equation of state. To circumvent early-time superhorizon instabilities, the energy-momentum transfer should occur in opposing directions within the two regimes, resulting in distinct phenomenological outcomes. We study quintessence and phantom non-dynamical and dynamical models in light of two independent Cosmic Microwave Background (CMB) experiments - the Planck satellite and the Atacama Cosmology Telescope. We analyze CMB data both independently and in combination with Supernovae (SN) distance moduli measurements from the Pantheon-Plus catalog and Baryon Acoustic Oscillations (BAO) from the SDSS-IV eBOSS survey. Our results update and extend the state-of-the-art analyses, significantly narrowing the parameter space allowed for these models and limiting their overall ability to reconcile cosmological tensions. Although considering different combinations of data leaves some freedom to increase $H_0$ towards the value measured by the SH0ES collaboration, our most constraining dataset (CMB+BAO+SN) indicates that fully reconciling the tension solely within the framework of IDE remains challenging.

    ↳ astro-ph.COhep-phPRD(2024)·73 citations
25. 25*

    Solution to the cosmological constant problem

    David L. Wiltshire🇳🇿

    I propose an observationally and theoretically consistent resolution of the cosmological constant problem: $\Lambda$ is a counterterm -- with a running coupling -- that balances the monopole celestial sky average of the kinetic energy of expansion of inhomogeneously distributed `small' cosmic voids. No other dark energy source is required. This solution relies on the first investigation of void statistics in cosmological simulations in full general relativity (arXiv:2403.15134). Results are consistent with parameters of the Timescape model of cosmological backreaction. Crucially, dynamical spatial curvature arises as time-varying spatial gradients of the kinetic spatial curvature, and depends directly on the void volume fraction. Its monopole average generates the cosmological term. This result potentially resolves the Hubble tension and offers new approaches to tackling other tensions and anomalies.

    ↳ gr-qcastro-ph.COhep-phhep-th4 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.