Tue·Jun 11, 2024Tuesday·June 11, 2024

1. 01*

   Signatures of Bulk Neutrinos in the Early Universe

   David McKeen🇨🇦 · John Ng🇨🇦 · Michael Shamma🇨🇦

   Neutrino masses and quantum gravity are strong reasons to extend the standard model of particle physics. A large extra dimension can be motivated by quantum gravity and can explain the small neutrino masses with new singlet states that propagate in the bulk. In such a case, a Kaluza-Klein tower of sterile neutrinos emerges. We revisit constraints on towers of sterile neutrinos that come from cosmological observables such as the effective number of noninteracting relativistic species and the dark matter density. These limits generically rule out micron-sized extra dimensions. We explore the weakening of these constraints to accommodate an extra dimension close to the micron size by assuming that the universe reheated after inflation to a low temperature. We discuss how such a possibility can be distinguished in the event of a positive signal in a cosmological observable.

   hep-phastro-ph.COPRD(2024)·5 citations
2. 02*

   Predictions and Tests for Semi-leptonic Decays of Beauty Hadrons,

   Elvio Di Salvo🇫🇷 · Ziad J. Ajaltouni🇫🇷 · Flavio Fontanelli🇮🇹

   We make predictions and propose tests for the semi-leptonic decays $B\to D^{(\ast )}l{\bar{\nu }}_l$ and ${\Lambda }_b\to {\Lambda }_{c}l{\bar{\nu }}_l$, with $l$ = $e$, $\mu$ and $\tau$. Preliminarily, we study such processes according to the $\ell -s$ scheme, which helps interpreting the results of previous analyses. Then, we write the angular distributions of those decays in the helicity formalism and suggest for each decay some tests for distinguishing among the various Dirac operators which may explain the tensions with the standard model. In particular, we propose, for $l$ = $e$ and $\mu$, to study the fully differential distribution. In the cases of the $B\to D^{\ast }$ and ${\Lambda }_b$ decays, important physical information can be extracted even after integrating over the momentum of the charged lepton, which is quite suitable for $l$ = $\tau$. Especially, the decay angular distribution of polarized ${\Lambda }_b$ depends on five observables, which assume different values according to the various new-physics interactions; one of these observables is related to the longitudinal polarization of the $\tau -{\bar{\nu }}_{\tau }$ system, which can be compared with the $D^{\ast }$ longitudinal polarization in the $B\to D^{\ast }$ decay. Moreover, we analyze the $\tau$ anomaly in the branching ratios of the semi-leptonic decays; to this end, we make some assumptions, which have a remarkable predictive power and lead to results in agreement with previous theoretical calculations. Thanks to these assumptions, we combine our present analysis of the ${\Lambda }_b$ decay with the previous ones of the $B\to D^{(\ast )}$ decays, getting strong constraints on the parameters which characterize the different new-physics operators and an indication on the most likely one.

   hep-phInt.J.Mod.Phys.A(2025)·1 citation
3. 03*

   New ideas in nonperturbative QCD -- I

   M.S. Lukashov🇷🇺 · Yu.A. Simonov🇷🇺

   The recent development of the Field Correlator Method (FCM) is discussed, with applications to the most interesting areas of QCD physics obtained in the lattice data and experiment. These areas include: a) the connection of colorelectric confinement with the basic quark and gluon condensates; b) the explicit form of the colorelectric deconfinement at a growing temperature $T$; c) the theory of the colormagnetic confinement at all temperatures; d) the theory of strong decays, the theory of pdf and jets in the instantaneous formalism with confinement. We demonstrate that the FCM with instantaneous formalism and confinement (instead of the light cone formalism and pure perturbation theory) can provide the way to the theory of QCD, which helps to describe world data without phenomenological parameters.

   hep-phhep-exhep-lathep-th2 citations
4. 04*

   Comparative Study of tau neutrinos event numbers in INO and JUNO detectors from Bartol Flux

   Kartik Joshi🇮🇳 · Satyajit Jena🇮🇳

   To expand our understanding of neutrino physics, scientific researchers of astroparticle Physics directs their goal of detecting atmospheric tau neutrinos in the GeV range. The effort will fundamentally unlock the nature of these elusive particles while also investigating muon neutrinos and tau neutrino oscillations. The Jiangmen Underground Neutrino Observatory (JUNO), which has already started its operations in 2024, and the India-based Neutrino Observatory (INO), which is not active right now but has future objectives in conducting research, have both emerged as key players in this field. These experiments used theoretical and experimental methodologies to understand the properties and behaviour of atmospheric tau neutrinos. The JUNO experiment, which has an estimated ability to detect around 50 events per year, and the INO, which used an impressive 50,000-ton iron slab as a detector, will contribute significantly in this domain. The detection of all tau neutrinos charged-current (CC) interactions with the detection material, which is divided into former and later events based on the timeline corresponding to scattering and capture in the detector; moreover, the KamLAND experiment is also capable of detecting these tau neutrinos decays, however, in smaller proportions, which could be possibly confused with background signals emerging from oscillations. This has been studied for both experiments for tau neutrinos nuclei cross-sections, and its standard value is taken as a base for calculations. Both INO and JUNO have 5 sigma sensitivity, which was exposed for 5 to 10 years.

   hep-ph0 citations
5. 05*

   Photon induced proton and anti-proton pair production with ultraperipheral heavy ion collisions at RHIC

   Cheng Zhang🇨🇳 · Li-Mao Zhang🇨🇳 · Ding Yu Shao🇨🇳

   We investigate proton-antiproton ($p\bar{p}$) pair production via photon-photon fusion in the ultra-peripheral collisions at RHIC, employing a joint impact parameter and transverse momentum dependent formalism. We consider proton exchange, $s$-channel resonance and hand-bag mechanisms, predicting differential distributions of $p\bar{p}$ production. Our theoretical predictions can be tested against future measurements at RHIC, to enhance our understanding of photon-photon interactions in strong electromagnetic fields.

   hep-phhep-exnucl-exnucl-thSCPMA(2025)·9 citations
6. 06*

   Simulating Parton Fragmentation on Quantum Computers

   Tianyin Li🇨🇳 · Hongxi Xing🇨🇳 · Dan-Bo Zhang🇨🇳

   Parton fragmentation functions (FFs) are indispensable for understanding processes of hadron production ubiquitously existing in high-energy collisions, but their first principle determination has never been realized due to the insurmountable difficulties in encoding their operator definition using traditional lattice methodology. We propose a framework that makes a first step for evaluating FFs utilizing quantum computing methodology. The key element is to construct a semi-inclusive hadron operator for filtering out hadrons of desired types in a collection of particles encoded in the quantum state. We illustrate the framework by elaborating on the Nambu-Jona-Lasinio model with numeral simulations. Remarkably, We show that the semi-inclusive hadron operator can be constructed efficiently with a variational quantum algorithm. Moreover, we develop error mitigation techniques tailed for accurately calculating the FFs in the presence of quantum noises. Our work opens a new avenue for investigating QCD hadronization on near-term quantum computers.

   hep-phnucl-thquant-ph21 citations
7. 07*

   Resummation of relativistic corrections to heavy quarkonium $+\gamma$ production at $Z$ factory

   Anton Trunin🇮🇹

   Cross sections of the heavy quarkonium production process $e^{+}{e}^{-}\to H+\gamma$ at the c.m. energy of $Z^0$-boson resonance are calculated at leading order in ${\alpha }_s$ with relativistic corrections resummed within the framework of nonrelativistic QCD (NRQCD). $S$- and $P$-wave charmonia and bottomonia are considered. For $J/\psi ({\rm Y})$ production, the result of vector-meson-dominance (VMD) approach is also given. Relativistic contributions to charmonium production are of the same magnitude as next-to-leading order QCD corrections, decreasing cross section 20-30%. Relativistic corrections to bottomonium production are negligible, not exceeding 2%.

   hep-ph2 citations
8. 08*

   LAYCAST: LAYered CAvern Surface Tracker at future electron-positron colliders

   Ye Lu🇨🇳 · Ying-nan Mao🇨🇳 · Kechen Wang🇨🇳 · Zeren Simon Wang🇹🇼

   We propose a detector concept, LAYered CAvern Surface Tracker (LAYCAST), to be installed on the ceiling and the wall of the cavern hosting the main experiment of future electron-positron colliders such as CEPC and FCC-ee. With detailed and realistic considerations of the design of such a new experiment, the proposed detector is dedicated to extending the sensitivity reach of the main detector to various theoretical scenarios of long-lived particles (LLPs). We study carefully four such scenarios involving a light scalar boson $X$, the heavy neutral lepton $N$, the lightest neutralino ${\tilde{\chi }}_1^0$ in the R-parity-violating supersymmetry, and the axion-like particle $a$. Long-lived light scalar bosons are considered to be produced from the Standard-Model (SM) Higgs boson's decay ($h\to XX$) at the center-of-mass energy $\sqrt{s}=$ 240 GeV, while the other three types of LLPs are produced either from $Z$-boson decays (viz. $Z\to \nu N,{\tilde{\chi }}_1^0{\tilde{\chi }}_1^0$) or direct scattering process ($e^{-}{e}^{+}\to \gamma a$) at $\sqrt{s}=$ 91.2 GeV, where $\gamma$ and $\nu$ denote the SM photon and neutrino, respectively. With Monte-Carlo simulations, we derive the sensitivities of the proposed experiment to these LLPs and the corresponding signal-event numbers. We also provide a dedicated estimate of a potentially important SM background from long-lived neutral kaons in hadronic $Z$ decays, and show that it is strongly suppressed by the combined requirements of the main detector and LAYCAST. Our findings show that LAYCAST can probe large new parameter space beyond both current bounds and the expected reach of the main experiments at CEPC and FCC-ee. Comparison with existing works in similar directions is also made.

   hep-phhep-exPRD(2026)·13 citations
9. 09*

   Long Range Azimuthal Correlation, Entanglement and Bell Inequality Violation by Spinning Gluons at the LHC

   Yuxun Guo🇺🇸 · Xiaohui Liu🇨🇳 · Feng Yuan🇺🇸 · Hua Xing Zhu🇨🇳

   We apply the recently developed concept of the nucleon energy-energy correlator (NEEC) for the gluon sector to investigate the long-range azimuthal angular correlations in proton-proton collisions at the LHC. The spinning gluon in these collisions will introduce a significant nonzero $\cos (2\varphi )$ asymmetries in both Higgs Boson and top quark pair productions. The genesis of the $\cos (2\varphi )$ correlation lies in the intricate quantum entanglement. Owing to the substantial $\cos (2\varphi )$ effect, the NEEC observable in Higgs Boson and $t\bar{t}$ production emerges as a pivotal avenue for delving into quantum entanglement and scrutinizing the Bell inequality at high-energy colliders.

   hep-phhep-exhep-thnucl-ex+1Research(2025)·26 citations
10. 10*

    Possible mixing of a diquark-antidiquark with a $p\bar{p}$ hadronic molecule

    Marek Karliner🇮🇱 · Jonathan L. Rosner🇺🇸

    We discuss the possibility that the two nearby resonances observed by BESIII partially below the \,$p\bar{p}$\, threshold might be due to mixing between two metastable states with the same $J^{PC}=0^{-+}$ quantum numbers, but rather different internal structure. One is a $p\bar{p}$ hadronic molecule and the other a bound state of a light-quark diquark and an antidiquark, both with spin 1 and isospin 0, a composite color antitriplet and triplet, respectively. The doubling of resonances, one of which may be interpreted as a hadronic molecule, while the other arises from $q\bar{q}$ annihilation in a state with vacuum quantum numbers may be a more general feature than the specific case considered here.

    hep-phPRD(2024)·5 citations
11. 11*

    Investigating the Molecular Nature of ${\Lambda }_b(6146)$ and ${\Lambda }_b(6152)$ via Strong Decays and Predicting Their Heavy-Quark Symmetry Partners

    Jing-wen Feng🇨🇳 · Cai Cheng🇨🇳 · Yin Huang🇨🇳

    Heavy quark symmetry can help us identify the internal structure of hadrons and predict new particles. In this study, we examine the strong decay modes of the observed ${\Lambda }_b^0(6146)$ and ${\Lambda }_b^0(6152)$, assuming these two states are molecular states primarily composed of ${\bar{B}}^{\ast }N$ component. The partial decay widths of the ${\bar{B}}^{\ast }N$ molecular state into the $\pi {\Sigma }_b$ and $\pi {\Sigma }_b^{\ast }$ final states through hadronic loops are calculated using effective Lagrangians. Our results, when compared with LHCb observations, support the interpretation of ${\Lambda }_b^0(6146)$ as a molecule primarily composed of ${\bar{B}}^{\ast }N$ components. However, the decay width of ${\Lambda }_b^0(6152)$ cannot be accurately reproduced within the molecular state framework. Based on the above results and heavy quark symmetry, we predict the existence of ${\bar{B}}^{\ast }N$ molecular states with $J^p=5/2^{+}$, which are the heavy quark spin symmetry partners of ${\Lambda }_b(6146)$, with masses in the range of 6195-6200 MeV. And the main decay is $\pi {\Sigma }_b^{\ast }$ channel. Moreover, there must existence of a $D^{\ast }N$ molecule with $J^p=3/2^{+}$, possible corresponding to the experimentally observed ${\Lambda }_c(2860{)}^{+}$. If ${\Lambda }_c(2880{)}^{+}$ is indeed the heavy quark flavor symmetry partner of ${\Lambda }_b(6152)$, it would exhibit a conventional three-quark structure. Therefore, we also propose the search for a $D^{\ast }N$ molecule with a spin-parity of $J^p=5/2^{+}$, which would be the heavy-quark spin partner state of ${\Lambda }_c(2860{)}^{+}$. It should be noted that these baryons may be mixed states, containing both molecular and three-quark components. These results can aid experiments in exploring the internal structure of these baryons.

    hep-ph0 citations
12. 12*

    Towards NNPDFpol2.0

    Felix Hekhorn🇫🇮

    We review the recent efforts in the NNPDF Collaboration towards a new global extraction of polarized parton distributions functions (pPDF). Polarized PDFs are highly relevant for the interpretation of current and future polarized high-energy experiments, including the upcoming Electron-Ion Collider (EIC). We present a recent study of the role played by heavy quark effects in polarized DIS, where we apply the FONLL general-mass variable-flavour-number scheme for the first time in a polarized setup and demonstrate the significant impact of charm mass corrections, specifically for the polarized gluon distribution. We show preliminary results (DIS-only) of this new pPDF release, NNPDFpol2.0, based on the NNPDF4.0 fitting machinery and the associated new theory prediction pipeline.

    hep-phPoS(2025)·7 citations
13. 13*

    Unraveling alignment pattern in high-energy particles via transverse momentum disbalance analysis

    I.P. Lokhtin🇷🇺 · A.V. Nikolskii🇷🇺 · A.M. Snigirev🇷🇺

    The hypothesis of the relation between strong azimuthal correlations, known as alignment, in families of hadrons and photons observed in cosmic ray experiments and the selection procedure of the highest-energy particles together with the transverse momentum conservation are tested in the framework of the HYDJET++ model. The results show that the high degree of alignment can appear in nucleus-nucleus interactions at reasonable values of the transverse momentum disbalance of most energetic detected particles.

    hep-phastro-ph.HEhep-exnucl-thEPJA(2025)·2 citations
14. 14*

    Precision calculations of the $D_{(s)}{D}_{(s)}V$ and $B_{(s)}{B}_{(s)}V$ couplings from light-cone sum rules

    Hua-Yu Jiang🇨🇳 · Su-Ping Jin🇨🇳

    We present an improved calculation of the $HHV$ ($H=D_{(s)},B_{(s)}$, $V=\rho$, $K^{\ast }$, $\omega$, and $\varphi$) coupling constants $g_{HHV}$ beyond leading order in ${\alpha }_s$ from QCD light-cone sum rules (LCSRs) by means of the light-cone distribution amplitudes (LCDAs) of light vector mesons. Near the light-cone, the next-to-leading order QCD corrections for the vacuum-to-vector-meson correlation function are included at leading power in ${\delta }_V=m_V/m_Q$ ($Q=b,c$) within the framework of hard-collinear factorization. The higher-twist corrections from two-particle and three-particle vector meson LCDAs are systematically incorporated at leading order in ${\alpha }_s$ by applying the method of background field in LCSRs. Based on these improvements, we perform a systematic computation of the strong coupling constants $g_{HHV}$ and extract the effective coupling $\beta$ of the heavy meson chiral perturbation theory (HM$\chi$PT). Furthermore, we accomplish the analysis for the relation between the coupling $g_{HHV}$ and the residue of the $H\to V$ transition form factor $A_0$ at heavy pseudoscalar pole. Additionally, we provide a detailed investigation of the $SU(3)$ flavour symmetry breaking effects and conduct a comparative analysis with results from previous studies.

    hep-phhep-exJHEP(2025)·4 citations
15. 15*

    Holographic complex potential of a quarkonium from deep learning

    Mahdi Mansouri🇮🇷 · Kazem Bitaghsir Fadafan · Xun Chen🇨🇳

    Utilizing an emergent metric developed from deep learning techniques, we determine the complex potential associated with static quarkonium. This study explores the disintegration process of quarkonium by analyzing the real component of this potential, which is crucial for understanding its stability in various conditions. We show that the dissociation length, the critical distance at which a quark and antiquark pair disintegrate, decreases as the temperature increases. Furthermore, our assessment of the imaginary component of the potential indicates an increase in the magnitude of the imaginary potential for quarkonium as temperatures rise. This enhancement contributes to the quarkonium's suppression within the quark-gluon plasma, mirroring the anticipated outcomes from QCD. Our findings not only confirm the theoretical predictions but also demonstrate the efficacy of deep learning methods in advancing our understanding of high-energy particle physics.

    hep-phhep-thEPJC(2026)·16 citations
16. 16*

    Topological structures, dark matter and gravitational waves in $E_6$

    Rinku Maji🇰🇷 · Qaisar Shafi🇺🇸 · Amit Tiwari🇺🇸

    We discuss the appearance of topological structures from the spontaneous breaking of $E_6$ to the Standard Model via its maximal subgroup $SO(10)\times U(1{)}_{\psi }$. They include dumbbells, metastable strings, as well as domain walls bounded by necklaces. We provide a novel scenario for producing metastable strings based on the symmetry breaking $U(1{)}_{\psi }⟶Z_8⟶Z_4$. The metastable string arises from the merger of $Z_8$ strings that bound a domain wall. An unbroken gauge $Z_2$ symmetry from $SO(10)$ breaking yields viable stable dark matter candidates as well as topologically stable strings. We discuss the gravitational wave emission from two varieties of cosmic strings, namely the superheavy metastable ones and the intermediate scale topologically stable cosmic strings.

    hep-phastro-ph.COJHEP(2024)·18 citations
17. 17*

    Dilatonic Couplings and the Relic Abundance of Ultralight Dark Matter

    Ahmad Alachkar🇬🇧 · Malcolm Fairbairn🇬🇧 · David J. E. Marsh🇬🇧

    Models of scalar field dark matter where the scalar is a dilaton have a special behaviour, since non-trivial couplings, $d$, to matter result in a contribution to the potential for the field which is proportional to the trace of the stress-energy tensor. We look in more detail at the dilaton mass, $m_{\varphi }$, and initial conditions required to yield the correct relic abundance for couplings that are not already excluded by terrestrial experiments. In minimal models with only couplings accessible to terrestrial searches, we find that dilaton dark matter with $m_{\varphi }\gtrsim 10^{-10}$ eV requires couplings suppressed compared to constraints from equivalence principle (EP) tests and fifth force searches in order to not produce too much dark matter, improving on the strongest current experimental constraints by up to $\sim \mathcal{O}(10)$, with consequences for the proposed mechanical resonator dilaton DM searches. In non-minimal or universally coupled models, the unconstrained couplings of the dilaton to e.g. the top quark can strongly influence the relic abundance at all masses. In particular, this implies that atom interferometry searches at masses $m_{\varphi }\approx 10^{-19}\text{ eV}$ are unable to constrain the early Universe behaviour or UV physics of the dilaton. We also find that dilatonic couplings allow for compatibility of $m_{\varphi }\gtrsim 10^{-7}\text{ eV}$ with an observably large tensor-to-scalar ratio in the cosmic microwave background, which is not possible for a decoupled scalar of the same mass.

    hep-phhep-thPRL(2025)·8 citations
18. 18*

    Particle Multi-Axis Transformer for Jet Tagging

    Muhammad Usman🇵🇰 · M Husnain Shahid🇵🇰 · Maheen Ejaz🇵🇰 · Ummay Hani🇵🇰 · Nayab Fatima🇵🇰 · Abdul Rehman Khan🇵🇰 · Asifullah Khan🇺🇸 · Nasir Majid Mirza🇵🇰

    Jet tagging is an essential categorization problem in high energy physics. In recent times, Deep Learning has not only risen to the challenge of jet tagging but also significantly improved its performance. In this article, we proposed an idea of a new architecture, Particle Multi-Axis transformer (ParMAT) which is a modified version of Particle transformer (ParT). ParMAT contains local and global spatial interactions within a single unit which improves its ability to handle various input lengths. We trained our model on JETCLASS, a publicly available large dataset that contains 100M jets of 10 different classes of particles. By integrating a parallel attention mechanism and pairwise interactions of particles in the attention mechanism, ParMAT achieves robustness and higher accuracy over the ParT and ParticleNet. The scalability of the model to huge datasets and its ability to automatically extract essential features demonstrate its potential for enhancing jet tagging.

    hep-phcs.LG5 citations
19. 19*

    Scaling violation in power corrections to energy correlators from the light-ray OPE

    Hao Chen🇨🇳 · Pier Francesco Monni🇨🇭 · Zhen Xu🇨🇳 · Hua Xing Zhu🇨🇳

    In recent years, energy correlators have emerged as a powerful tool to explore the field theoretic structure of strong interactions at particle colliders. In this Letter we initiate a novel study of the non-perturbative power corrections to the projected $N$-point energy correlators in the limit where the angle between the detectors is small. Using the light-ray operator product expansion (OPE) as a guiding principle, we derive the power corrections in terms of two non-perturbative quantities describing the fragmentation of quarks and gluons. In analogy with their perturbative leading-power counterpart, we show that power corrections obey a classical scaling behavior that is violated at the quantum level. This crucially results in a dependence on the hard scale $Q$ of the problem that is calculable in perturbation theory. Our analytic predictions are successfully tested against Monte Carlo simulations for both lepton and hadron colliders, marking a significant step forward in the understanding of these observables.

    hep-phPRL(2024)·62 citations
20. 20*

    Impact of SMEFT renormalisation group running on Higgs production at the LHC

    Fabio Maltoni🇧🇪 · Giuseppe Ventura🇬🇧 · Eleni Vryonidou🇬🇧

    We study the effects of the one-loop renormalisation group running/mixing of the Wilson coefficients in the standard model effective field theory on the predictions for $Hj$, $t\bar{t}H$ and $HH$ production at the LHC. We focus on a subset of operators closed under QCD corrections and explore the differences between employing a fixed or dynamical scale on the SMEFT predictions for key observables such as the Higgs transverse momentum and the Higgs pair invariant mass. We then study the impact of consistently taking into account renormalisation group effects on the constraints that can be obtained on the Wilson coefficients through current and future measurements at the LHC.

    hep-phJHEP(2024)·37 citations
21. 21*

    Top-quark pair production as a probe of light top-philic scalars and anomalous Higgs interactions

    Fabio Maltoni🇧🇪 · Davide Pagani🇮🇹 · Simone Tentori🇧🇪

    We compute the effects due to the virtual exchange (or the soft emission) of a scalar particle with generic couplings to the top quark in $t\bar{t}$ pair production at the LHC. We apply the results to two cases of interest, extending and completing previous studies. First, we consider the indirect search for light ($m_S<2m_t$) top-philic scalars with CP-even and/or CP-odd interactions. Second, we investigate how to set constraints on anomalous Yukawa couplings of the Higgs boson to the top quark. Our results show that the current precision of experimental data together with the accuracy of the SM predictions make such indirect determinations a powerful probe for new physics.

    hep-phhep-exJHEP(2024)·20 citations
22. 22*

    Inflaton Production of Scalar Dark Matter through Fluctuations and Scattering

    Gongjun Choi🇺🇸 · Marcos A. G. Garcia🇲🇽 · Wenqi Ke🇺🇸 · Yann Mambrini🇫🇷 · Keith A. Olive🇺🇸 · Sarunas Verner🇺🇸

    We study the effects on particle production of a Planck-suppressed coupling between the inflaton and a scalar dark matter candidate, $\chi$. In the absence of this coupling, the dominant source for the relic density of $\chi$ is the long wavelength modes produced from the scalar field fluctuations during inflation. In this case, there are strong constraints on the mass of the scalar and the reheating temperature after inflation from the present-day relic density of $\chi$ (assuming $\chi$ is stable). When a coupling $\sigma {\varphi }^2{\chi }^2$ is introduced, with $\sigma =\tilde{\sigma }{m}_{\varphi }^2/M_P^2\sim 10^{-10}\tilde{\sigma }$, where $m_{\varphi }$ is the inflaton mass, the allowed parameter space begins to open up considerably even for $\tilde{\sigma }$ as small as $\gtrsim 10^{-7}$. For $\tilde{\sigma }\gtrsim \frac{9}{16}$, particle production is dominated by the scattering of the inflaton condensate, either through single graviton exchange or the contact interaction between $\varphi$ and $\chi$. In this regime, the range of allowed masses and reheating temperatures is maximal. For $0.004<\tilde{\sigma }<50$, constraints from isocurvature fluctuations are satisfied, and the production from parametric resonance can be neglected.

    hep-phastro-ph.COhep-thPRD(2024)·19 citations
23. 23*

    Analysis of the Third Harmonic of a Vacuum Response in a Subcritical Laser Field

    V.V. Dmitriev · S.A. Smolyansky · V.A. Tseryupa

    We investigate a nonlinear response of the physical vacuum by the example of the third harmonic in radiation of the electron-positron-photon plasma excited by a strong time dependent electric field at the focus spot of counterpropagating laser pulses. The investigation was developed within the framework of the Bogoliubov-Born-Green-Kirkwood-Yvon kinetic theory nonperturbatively describing vacuum creation of the quasiparticle electron-positron plasma (EPP) and different channels of its interaction with the photon subsystem in the single-photon approximation that are opened in the presence of a strong semiclassical field. We investigate the radiation of EPP in the annihilation channel on the basis of the well known approximations and compare the obtained result with the semiclassical radiation of the plasma oscillations. In the high-frequency range for large adiabaticity parameter the quantum radiation dominates in comparison with the semiclassical one.

    hep-phhep-thphysics.plasm-phPhys.Atom.Nucl.(2023)·1 citation
24. 24*

    2D BAO vs 3D BAO: Hints for new physics?

    Ruchika🇮🇹

    As next-generation telescopes and observational surveys continue to expand the boundaries of our understanding, tensions and discrepancies between observational datasets are becoming increasingly prominent. In this work, we focus on one such discrepancy: the differences between 2D and 3D Baryon Acoustic Oscillation (BAO) measurements. Without extending beyond the standard $\Lambda$CDM framework, we systematically study and highlight this discrepancy in different parameter spaces. This work examines the constraints on fundamental cosmological parameters ($H_0$, $r_d$, ${\Omega }_m$) derived from Baryon Acoustic Oscillation (BAO) and Type Ia Supernovae (SNIa) data. By analyzing BAO observational datasets from two distinct methodologies (2D and 3D) alongside the Pantheon Plus SNIa sample, we identify a significant systematic difference: 2D BAO measurements consistently yield higher values of $h{r}_d$ compared to both 3D BAO and DESI analyses. While 2D BAO measurements appear to bridge the Hubble tension by simultaneously accommodating both a higher $H_0$ value (aligning with SH0ES) and a larger sound horizon $r_d$ (matching Planck), this apparent reconciliation comes at the cost of introducing tension with the well-constrained Planck measurement of ${\Omega }_{m0}{h}^2$. This behavior arises because of systematically higher values of the product $H_0{r}_d$ observed in 2D BAO analysis compared to 3D analyses. Therefore, given these systematic differences, we advocate for careful consideration when using 2D BAO measurements to address the Hubble tension, suggesting that understanding the origin of this 2D-3D discrepancy should be a priority for future investigations.

    ↳ astro-ph.COhep-phPRD(2025)·16 citations
25. 25*

    The History of Primordial Black Holes

    Bernard J. Carr🇬🇧 · Anne M. Green🇬🇧

    We overview the history of primordial black hole (PBH) research from the first papers around 50 years ago to the present epoch. The history may be divided into four periods, the dividing lines being marked by three key developments: inflation on the theoretical front and the detection of microlensing events by the MACHO project and gravitational waves by the LIGO/Virgo/KAGRA project on the observation front. However, they are also characterised by somewhat different focuses of research. The period 1967-1980 covered the groundbreaking work on PBH formation and evaporation. The period 1980-1996 mainly focussed on their formation, while the period 1996-2016 consolidated the work on formation but also collated the constraints on the PBH abundance. In the period 2016-2024 there was a shift of emphasis to the search for evidence for PBHs and - while opinions about the strength of the purported evidence vary - this has motivated more careful studies of some aspects of the subject. Certainly the soaring number of papers on PBHs in this last period indicates a growing interest in the topic.

    ↳ astro-ph.COhep-ph42 citations
26. 26*

    Bubbles kick off primordial black holes to form more binaries

    Zi-Yan Yuwen🇨🇳 · Cristian Joana🇨🇳 · Shao-Jiang Wang🇨🇳 · Rong-Gen Cai🇨🇳

    Primordial black holes (PBHs) may form before cosmological first-order phase transitions, leading to inevitable collisions between PBHs and bubble walls. In this Letter, we have simulated for the first time the co-evolution of an expanding scalar wall passing through a black hole with full numerical relativity. This black hole-bubble wall collision yields multiple far-reaching phenomena, including the PBH mass growth, gravitational wave radiations, and momentum recoil that endows PBHs with additional velocities, approximately doubling the formation rate for PBH binaries and hence strengthening the observational constraints on the PBH abundances.

    ↳ gr-qcastro-ph.COhep-phPRResearch(2025)·10 citations
27. 27*

    Minimal Cuts and Genealogical Constraints on Feynman Integrals

    Holmfridur S. Hannesdottir🇺🇸 · Luke Lippstreu🇬🇧 · Andrew J. McLeod🇬🇧 · Maria Polackova🇬🇧

    We introduce an efficient method for deriving hierarchical constraints on the discontinuities of individual Feynman integrals. This method can be applied at any loop order and particle multiplicity, and to any configuration of massive or massless virtual particles. The resulting constraints hold to all orders in dimensional regularization, and complement the extended Steinmann relations -- which restrict adjacent sequential discontinuities -- by disallowing ordered pairs of discontinuities from appearing even when separated by (any number of) other discontinuities. We focus on a preferred class of hierarchical constraints, which we refer to as \emph{genealogical constraints}, that govern what singularities can follow from certain \emph{minimal cuts} that act as the primogenitors of the discontinuities that appear in Feynman integrals. While deriving the full set of hierarchical constraints on a given Feynman integral generally requires identifying all solutions to the (blown up) Landau equations, these genealogical constraints can be worked out with only minimal information about what singularities may appear. We illustrate the power of this new method in examples at one, two, and three loops, and provide evidence that genealogical constraints restrict the analytic structure of Feynman integrals significantly more than the extended Steinmann relations.

    ↳ hep-thhep-ph14 citations
28. 28*

    The matrix model of two-color one-flavor QCD: The ultra-strong coupling regime

    Nirmalendu Acharyya🇮🇳 · Prasanjit Aich🇮🇳 · Arkajyoti Bandyopadhyay🇮🇳 · Sachindeo Vaidya🇮🇳

    Using variational methods, we numerically investigate the matrix model for the two-color QCD coupled to a single quark (matrix-QCD${}_{2,1}$) in the limit of ultra-strong Yang-Mills coupling ($g=\infty$). The spectrum of the model has superselection sectors labelled by baryon number $B$ and spin $J$. We study sectors with $B=0,1,2$ and $J=0,1$, which may be organized as mesons, (anti-)diquarks and (anti-)tetraquarks. For each of these sectors, we study the properties of the respective ground states in both chiral and heavy quark limits, and uncover a rich quantum phase transition (QPT) structure. We also investigate the division of the total spin between the glue and the quark and show that glue contribution is significant for several of these sectors. For the $(B,J)=(0,0)$ sector, we find that the dominant glue contribution to the ground state comes from reducible connections. Finally, in the presence of non-trivial baryon chemical potential $\mu$, we construct the phase diagram of the model. For sufficiently large $\mu$, we find that the ground state of the theory may have non-zero spin.

    ↳ hep-thhep-lathep-phPRD(2024)·9 citations
29. 29*

    Multi-Generational Black Hole Population Analysis with an Astrophysically Informed Mass Function

    Yannick Ulrich🇬🇧 · Djuna Croon🇬🇧 · Jeremy Sakstein🇺🇸 · Samuel McDermott🇺🇸

    We analyze the population statistics of black holes in the LIGO/Virgo/KAGRA GWTC-3 catalog using a parametric mass function derived from simulations of massive stars experiencing pulsational pair-instability supernovae (PPISN). Our formalism enables us to separate the black hole mass function into sub-populations corresponding to mergers between objects formed via different astrophysical pathways, allowing us to infer the properties of black holes formed from stellar collapse and black holes formed via prior mergers separately. Applying this formalism, we find that this model fits the data better than the powerlaw+peak model with Bayes factor $9.7\pm 0.1$. We measure the location of the lower edge of the upper black hole mass gap to be $M_{\mathrm{BHMG}}=84.05_{-12.88}^{+17.19}{\mathrm{M}}_{\odot }$, providing evidence that the $35{\mathrm{M}}_{\odot }$ Gaussian peak detected in the data using other models is not associated with the PPISN pile-up predicted to precede this gap. Incorporating spin, we find that the normalized spins of stellar remnant black holes are close to zero while those of higher generation black holes tend to larger values. All of these results are in accordance with the predictions of stellar structure theory and black hole merger scenarios. Finally, we combine our mass function with the spectral siren method for measuring the Hubble constant to find $H_0=36.19_{-10.91}^{17.50}$ km/s/Mpc and discuss potential explanations of this low value. Our results demonstrate how astrophysically-informed mass functions can facilitate the interpretation of gravitational wave catalog data to provide information about black hole formation and cosmology. Future data releases will improve the precision of our measurements.

    ↳ astro-ph.HEastro-ph.COgr-qchep-ph9 citations
30. 30*

    Higgs cross-section ( including di-Higgs ) with CMS and ATLAS

    Torben Lange (on behalf of the ATLAS and CMS Collaborations)🇪🇪

    Since the discovery of the Higgs boson in 2012 by the ATLAS and CMS Collaborations a lot of progress has been made in verifying the nature of this new bosonic particle. Still, questions remain as to whether this new particle is the standard model (SM) Higgs boson, and whether it gives us hints of where physics beyond the SM (BSM) might be hidden. This overview tries to tackle these questions by looking at three types of analyses 1) Total cross section measurements of the various Higgs boson production and decay modes, allowing us access to the various Higgs boson couplings to SM bosons and fermions, 2) Differential Higgs boson cross section measurements such as in the STXS framework allowing for a model independent search for BSM and, finally, 3) The searches for di-Higgs production which give access to the trilinear Higgs self coupling $\lambda$ and the Higgs potential itself.

    ↳ hep-exhep-ph0 citations
31. 31*

    Implications of DES 5YR SNe Dataset for $\Lambda$CDM

    Eoin Ó Colgáin🇮🇪 · Saeed Pourojaghi🇮🇷 · M. M. Sheikh-Jabbari🇮🇷

    Dark Energy Survey five-year supernovae data (DES 5YR SNe) in conjunction with Planck CMB and Dark Energy Spectroscopic Instrument (DESI) BAO data has detected a strong dynamical dark energy (DE) deviation from the $\Lambda$CDM model.Here we shift the focus of DES data to the pressureless matter sector in the $\Lambda$CDM model by studying the matter density parameter ${\Omega }_m$. Employing primarily frequentist profile likelihoods, supported by complementary Bayesian methods, we demonstrate that ${\Omega }_m$ increases with effective redshift in the DES data up to a point that there is a $2.5\sigma$ discrepancy with Planck. We relax the traditional ${\Omega }_m\le 1$ prior to demonstrate negative DE densities ${\Omega }_m>1$ at the highest effective redshift probed. Nevertheless, the largest discrepancy with Planck occurs for profile likelihoods and posteriors peaked at ${\Omega }_m<1$ in the traditional $\Lambda$CDM regime. Our findings corroborate earlier observations in Pantheon and Pantheon+ datasets with an independent SNe dataset with a higher effective redshift. In an appendix, we confirm that curvature ${\Omega }_k$ decreases with effective redshift disfavouring a flat Universe in higher redshift DES SNe at $>3\sigma$. Our choice of ${\Omega }_k$ prior leads to an underestimation of the tension with a flat Universe.

    ↳ astro-ph.COgr-qchep-phhep-thEPJC(2025)·84 citations
32. 32*

    Searching for Pseudo-Dirac neutrinos from Astrophysical sources in IceCube data

    Khushboo Dixit🇿🇦 · Luis Salvador Miranda🇧🇷 · Soebur Razzaque🇿🇦

    We analyze IceCube public data from its IC86 configuration, namely PSTracks event selection, to search for pseudo-Dirac signatures in high-energy neutrinos from astrophysical sources. Neutrino flux from astrophysical sources is reduced in the pseudo-Dirac scenario due to the conversion of active-to-sterile neutrinos as compared to the neutrino oscillation scenario of only three active neutrinos over astrophysical distances. We fit IceCube data using astrophysical flux models for four point-like sources in both scenarios and constrain the active-sterile mass-square-difference in the absence of any evidence for the pseudo-Dirac scenario. We present the exclusion regions for the common mass-squared difference $\delta m^2$, inducing active-sterile oscillations, for all three neutrino flavors. This includes results from individual sources as well as from a stacking analysis that combines data from the four sources. Our findings indicate that the exclusion region is $\delta m^2\in [2.1\times 10^{-21}-2.0\times 10^{-16}]$ eV${}^2$ with $\ge 90\%$ confidence level (CL) significance for neutrino energies ranging from 0.5 TeV to 1 PeV. When we extend the energy range down to 0.1 TeV, the exclusion region broadens to $\delta m^2\in [1.1\times 10^{-21}-3.0\times 10^{-16}]$ eV${}^2$ at $\ge 90\%$ CL.

    ↳ astro-ph.HEhep-exhep-phEPJC(2025)·10 citations
33. 33*

    Macroscopic quantum superpositions in superconducting circuits

    Vitoria A. de Souza🇧🇷 · Caio C. Holanda Ribeiro🇧🇷 · Vitorio A. De Lorenci🇧🇷

    A possible route to test whether macroscopic systems can acquire quantum features using superconducting circuits is here presented. It is shown that under general assumptions a classical test current pulse of fixed energy and adjustable length acquires quantum features after interacting with the quantum vacuum of the photon field. Further, it is shown that the mere existence of vacuum fluctuations can lead to the breakdown of energy and momentum conservation, and as the length of the pulse grows with respect to the characteristic size of the quantum system, the test pulse undergoes quantum-to-classical transition. This model differs from previous ones for its simplicity and points towards a new way of creating correlated systems suitable for quantum-based technology.

    ↳ quant-phhep-ph2 citations
34. 34*

    Instanton Density Operator in Lattice QCD from Higher Category Theory

    Jing-Yuan Chen🇨🇳

    A natural definition for instanton density operator in lattice QCD has long been desired. We show this problem is, and has to be, solved by higher category theory. The problem is solved by refining at a conceptual level the Yang-Mills theory on lattice, in order to recover the homotopy information in the continuum, which would have been lost if we put the theory on lattice in the traditional way. The refinement needed is a generalization--through the lens of higher category theory--of the familiar process of Villainization that captures winding in lattice XY model and Dirac quantization in lattice Maxwell theory. The apparent difference is that Villainization is in the end described by principal bundles, hence familiar, but more general topological operators can only be captured on the lattice by more flexible structures beyond the usual group theory and fibre bundles, making the language of categories natural and necessary. The key structure we need for our particular problem is called multiplicative bundle gerbe, based upon which we can construct suitable structures to naturally define the 2d Wess-Zumino-Witten term, 3d skyrmion density operator and 4d hedgehog defect for lattice $S^3$ pion vacua non-linear sigma model, and the 3d Chern-Simons term, 4d instanton density operator and 5d Yang monopole defect for lattice $SU(N)$ Yang-Mills theory; the structures behind the non-linear sigma model and the Yang-Mills theory are related via an implicit Yang-Baxter equation. In a broader perspective, higher category theory enables us to rethink more systematically the relation between continuum quantum field theory and lattice quantum field theory. We sketch a proposal towards a general machinery that constructs the suitably refined lattice degrees of freedom for a given non-linear sigma model or gauge theory in the continuum, realizing the desired topological operators on the lattice.

    ↳ hep-latcond-mat.str-elhep-phhep-th+2SciPost Phys.(2025)·20 citations
35. 35*

    Uncertainty quantification for $\mu \to e$ conversion in nuclei: charge distributions

    Frederic Noël🇨🇭 · Martin Hoferichter🇨🇭

    Predicting the rate for $\mu \to e$ conversion in nuclei for a given set of effective operators mediating the violation of lepton flavor symmetry crucially depends on hadronic and nuclear matrix elements. In particular, the uncertainties inherent in this non-perturbative input limit the discriminating power that can be achieved among operators by studying different target isotopes. In order to quantify the associated uncertainties, as a first step, we go back to nuclear charge densities and propagate the uncertainties from electron scattering data for a range of isotopes relevant for $\mu \to e$ conversion in nuclei, including ${}^{40,48}$Ca, ${}^{48,50}$Ti, and ${}^{27}$Al. We provide as central results Fourier-Bessel expansions of the corresponding charge distributions with complete covariance matrices, accounting for Coulomb-distortion effects in a self-consistent manner throughout the calculation. As an application, we evaluate the overlap integrals for $\mu \to e$ conversion mediated by dipole operators. In combination with modern ab-initio methods, our results will allow for the evaluation of general $\mu \to e$ conversion rates with quantified uncertainties.

    ↳ nucl-thhep-exhep-phnucl-exJHEP(2024)·13 citations
36. 36*

    Wrong Signs are Alright

    David E. Kaplan🇺🇸 · Surjeet Rajendran🇺🇸 · Francesco Serra🇺🇸

    It has been shown that some Lorentz-invariant quantum field theories, such as those with higher-dimensional operators with negative coefficients, lead to superluminality on some classical backgrounds. While superluminality by itself is not logically inconsistent, these theories also predict the formation of closed time-like curves at the classical level, starting from initial conditions without such curves. This leads to the formation of a Cauchy Horizon which prevents a complete description of the time evolution of such systems. Inspired by the chronology protection arguments of General Relativity, we show that quantum mechanical effects from low energy quanta strongly backreact on such configurations, exciting unknown short-distance degrees of freedom and invalidating the classical predictions. Thus, there is no obvious low-energy obstruction to the existence of these operators.

    ↳ hep-thhep-phJHEP(2025)·10 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.