Mon·Apr 29, 2024Monday·April 29, 2024

1. 01*

   The Theoretical Study of $p\bar{p}\to \bar{\Lambda }\Sigma \eta$ Reaction

   Aojia Xu🇨🇳 · Ruitian Li🇨🇳 · Xuan Luo🇨🇳 · Hao Sun🇨🇳

   We study the production of hyperon resonances in the $p\bar{p}\to \bar{\Lambda }\Sigma \eta$ reaction within an effective Lagrangian approach. The model includes the production of $\Sigma (1750)$ and $\Lambda (1670)$ in the intermediate state excited by the $K$ and $K^{\ast }$ meson exchanges between the initial proton and antiproton. Due to the large coupling of $\Sigma (1750)\Sigma \eta$ vertex, $\Sigma (1750)$ is found a significant contribution near the threshold in this reaction. We provide total and differential cross section predictions for the reation and discuss the possible influence of $\Sigma (1750)\Sigma \eta$ vertex coupling and model parameters, which will be useful in future experimental studies. This reaction can provide a platform for studying the features of $\Sigma (1750)$ resonance, especially the coupling to $\Sigma \eta$ channel.

   hep-phnucl-thEPJC(2024)·3 citations
2. 02*

   Distinguishing charged lepton flavor violation scenarios with inelastic $\mu \to e$ conversion

   W. C. Haxton🇺🇸 · Evan Rule🇺🇸

   The Mu2e and COMET experiments are expected to improve existing limits on charged lepton flavor violation (CLFV) by roughly four orders of magnitude. $\mu \to e$ conversion experiments are typically optimized for electrons produced without nuclear excitation, as this maximizes the electron energy and minimizes backgrounds from the free decay of the muon. Here we argue that Mu2e and COMET will be able to extract additional constraints on CLFV from inelastic $\mu \to e$ conversion, given the ${}^{27}$Al target they have chosen and backgrounds they anticipate. We describe CLFV scenarios in which inelastic CLFV can induce measurable distortions in the near-endpoint spectrum of conversion electrons, including cases where certain contributing operators cannot be probed in elastic $\mu \to e$ conversion. We extend the nonrelativistic EFT treatment of elastic $\mu \to e$ conversion to include the new nuclear operators needed for the inelastic process, evaluate the associated nuclear response functions, and describe several new-physics scenarios where the inelastic process can provide additional information on CLFV.

   hep-phnucl-thPRL(2024)·9 citations
3. 03*

   Most general neutron decay correlations: Standard Model recoil and radiative corrections

   Chien-Yeah Seng🇺🇸

   To continue from our previous work Phys.Rev.D 109(2024),073007, we derive the full Standard Model prediction of the most general free neutron differential decay rate with all massive particles (neutron, proton and electron) polarized, including the $\mathcal{O}(1/m_N)$ recoil corrections and $\mathcal{O}(\alpha /\pi )$ radiative corrections. For the latter we adopt the newly-developed pseudo-neutrino formalism which is compatible to realistic experimental setups, in which neutrinos and photons are not detected. We also provide readily-executable Mathematica notebooks to evaluate these corrections.

   hep-phhep-exhep-latnucl-ex+1PRD(2024)·2 citations
4. 04*

   Canonical interpretation of the newly observed $J^P=1^{+}$ structure $X(2085)$

   Tian-Ge Li🇨🇳 · Sheng-Chao Zhang🇨🇳 · Guan-Ying Wang🇨🇳 · Qi-Fang Lü🇨🇳

   Inspired by the newly observed $X(2085)$ by the BESIII Collaboration, we study the strong decay behaviors of excited axialvector strange mesons within the quark pair creation model. Our results indicate that the $K_1(1793)/K_1(1861)$ can be regarded as the same $K_1(2P)$ state, and the $K_1(1911)$ is assigned as the $K_1(2P^{\prime })$ state. Considering the mass, spin-parity, and decay behaviors, we interpret the newly observed $X(2085)$ as the radially excited $K_1(3P)$ state, which mainly decays into the $\rho (1450)K$, $\omega (1420)K$, $\pi K^{\ast }(1410)$, $\rho K_1(1270)$, and $\rho K^{\ast }(892)$ final states. Also, the width of $K_1(3P^{\prime })$ state is predicted to be about 300 MeV, which can be searched for by future experiments. We expect that present calculations can help us to better understand the nature of the $X(2085)$ structure.

   hep-phPRD(2024)·3 citations
5. 05*

   Bounds on heavy axions with an X-ray free electron laser

   Jack W. D. Halliday🇬🇧 · Giacomo Marocco🇺🇸 · Konstantin A. Beyer🇩🇪 · Charles Heaton🇬🇧 · Motoaki Nakatsutsumi🇩🇪 · Thomas R. Preston🇩🇪 · Charles D. Arrowsmith🇬🇧 · Carsten Baehtz🇩🇪 · Sebastian Goede🇩🇪 · Oliver Humphries🇩🇪 · Alejandro Laso Garcia🇩🇪 · Richard Plackett🇬🇧 and 9 other authors

   We present new exclusion bounds obtained at the European X-ray Free Electron Laser facility (EuXFEL) on axion-like particles (ALPs) in the mass range 10^{-3} eV < m_a < 10^4 eV. Our experiment exploits the Primakoff effect via which photons can, in the presence of a strong external electric field, decay into axions, which then convert back into photons after passing through an opaque wall. While similar searches have been performed previously at a 3^rd generation synchrotron, our work demonstrates improved sensitivity, exploiting the higher brightness of X-rays at EuXFEL.

   hep-phhep-exphysics.atom-phphysics.ins-detPRL(2025)·19 citations
6. 06*

   Testing the Origins of Neutrino Mass with Supernova Neutrino Time Delay

   Shao-Feng Ge🇨🇳 · Chui-Fan Kong🇨🇳 · Alexei Y. Smirnov🇩🇪

   The origin of neutrino masses remains unknown. Both the vacuum mass and the dark mass generated by the neutrino interaction with dark matter (DM) particles or fields can fit the current oscillation data. The dark mass squared is proportional to the DM number density and therefore varies on the galactic scale with much larger values around the Galactic Center. This affects the group velocity and the arrival time delay of core-collapse supernovae (SN) neutrinos. This time delay, especially for the ${\nu }_e$ neutronization peak with a sharp time structure, can be used to distinguish the vacuum and dark neutrino masses. For illustration, we explore the potential of DUNE which is sensitive to ${\nu }_e$. Our simulations show that DUNE can distinguish the two neutrino mass origins at more than $5\sigma$C.L., depending on the observed local value of neutrino mass, the neutrino mass ordering, the DM density profile, and the SN location.

   hep-phastro-ph.HEhep-exPRL(2024)·15 citations
7. 07*

   Indirect detection of dark matter absorption in the Galactic Center

   Kimberly K. Boddy🇺🇸 · Bhaskar Dutta🇺🇸 · Addy J. Evans🇺🇸 · Wei-Chih Huang🇺🇸 · Stacie Moltner🇺🇸 · Louis E. Strigari🇺🇸

   We consider the nuclear absorption of dark matter as an alternative to the typical indirect detection search channels of dark matter decay or annihilation. In this scenario, an atomic nucleus transitions to an excited state by absorbing a pseudoscalar dark matter particle and promptly emits a photon as it transitions back to its ground state. The nuclear excitation of carbon and oxygen in the Galactic Center would produce a discrete photon spectrum in the $\mathcal{O}(10)$ MeV range that could be detected by gamma-ray telescopes. Using the \texttt{BIGSTICK} large-scale shell-model code, we calculate the excitation energies of carbon and oxygen. We constrain the dark matter-nucleus coupling for current COMPTEL data, and provide projections for future experiments AMEGO-X, e-ASTROGAM, and GRAMS for dark matter masses from $\sim$ 10 to 30 MeV. We find the excitation process to be very sensitive to the dark matter mass and find that the future experiments considered would improve constraints on the dark matter-nucleus coupling within an order of magnitude.

   hep-phastro-ph.HEJCAP(2025)·4 citations
8. 08*

   Disentangling left and right-handed neutrino effects in $B\to K^{(\ast )}\nu \nu$

   L. P. S. Leal🇧🇷 · S. Rosauro-Alcaraz🇫🇷

   The first observation of $\mathcal{B}\left(B^{+}\to K^{+}\nu \nu \right)$ by the Belle II experiment lies almost $3\sigma$ away from the Standard Model expectation. In this letter we study this result in the SMEFT, extended by a light right-handed neutrino. We explore the correlations between the measured decay rate and other observables, such as $\mathcal{B}\left(B\to K^{\ast }\nu \nu \right)$ and $F_L\left(B\to K^{\ast }\nu \nu \right)$, showing that they could disentangle among scenarios involving left-handed neutrinos and those with the right-handed ones. Furthermore, we find that the high-$p_T$ tails of Drell-Yan processes studied at LHC provide important constraints that help us exclude some of the scenarios consistent with the Belle II result.

   hep-phEPJC(2024)·35 citations
9. 09*

   Quasi particle model vs lattice QCD thermodynamics: extension to $N_f=2+1+1$ flavors and momentum dependent quark masses

   Maria Lucia Sambataro (1 and 2)🇮🇹 · Vincenzo Greco (1 and 2)🇮🇹 · Gabriele Parisi (1 and 2)🇮🇹 · Salvatore Plumari (1 and 2) ((1) Department of Physics and Astronomy 'E. Majorana', University of Catania, (2) Laboratori Nazionali del Sud, INFN-LNS)🇮🇹

   In the last decade a Quasi-Particle Model ($QPM$) has supplied the basis for the study of HQ production in ultra-relativistic AA collisions, allowing for a phenomenological estimate of the HQ diffusion coefficient $D_s(T)$. Taking advantage of the new lattice QCD results for the Equation of State (EoS) with 2+1+1 dynamical flavors, we extend our $QPM$ approach from $N_f=2+1$ to $N_f=2+1+1$, in which the charm quark is included. Given an effective coupling $g(T)$ fixed by a fit to the lQCD energy density $ϵ(T)$, we evaluate the impact of different temperature parametrizations of charm quark mass on EoS and susceptibilities ${\chi }_q(T)$ of light, ${\chi }_s(T)$ of strange and ${\chi }_c(T)$ of charm quarks, the last favouring a charm quark mass increasing toward $T_c$. We also explore the extension of the $QPM$ approach to a more realistic approach, that we label $QP{M}_p$, in which quark and gluon masses explicitly depend on their momentum converging to the current quark mass at high momenta, as expected from asymptotic free dynamics. The $QP{M}_p$ is seen to allow for a simultaneous quantitative description not only of the EoS but also of the quark susceptibilities (${\chi }_q(T)$, ${\chi }_s(T)$), which instead are underestimated in the simple $QPM$ model. Furthermore, evaluating the spatial diffusion coefficient $2\pi T{D}_s(T)$ in the $QP{M}_p$, we find it is also significantly closer than $QPM$ to the recent lQCD data performed including dynamical fermions. Finally, in a 1+1D expanding system, we evaluate the $R_{AA}(p_T)$ in the $QPM$ and $QP{M}_p$, finding a significant reduction at low momenta for $QP{M}_p$ which could lead in a realistic scenario to a better agreement to experimental data.

   hep-phEPJC(2024)·34 citations
10. 10*

    Nuclear suppression of coherent $J/\psi$ photoproduction in heavy-ion UPCs and leading twist nuclear shadowing

    V. Guzey (Jyvaskyla U. and Helsinki Inst. of Phys.)🇫🇮 · M. Strikman (Penn State U.)🇺🇸

    We determine the nuclear suppression factor $S_{Pb}(x)$, where $x=M_{J/\psi }^2/W_{\gamma p}^2$ with $M_{J/\psi }$ the $J/\psi$ mass and $W_{\gamma p}$ the photon-nucleon energy, for the cross section of coherent $J/\psi$ photoproduction in heavy-ion ultraperipheral collisions (UPCs) at the Large Hadron Collider (LHC) and Relativistic Heavy Ion Collider (RHIC) by performing the ${\chi }^2$ fit to all available data on the cross section $d{\sigma }^{AA\to J/\psi AA}/dy$ as a function of the $J/\psi$ rapidity $y$ and the photoproduction cross section ${\sigma }^{\gamma A\to J/\psi A}(W_{\gamma p})$ as a function of $W_{\gamma p}$. We find that while the $d{\sigma }^{AA\to J/\psi AA}/dy$ data alone constrain $S_{Pb}(x)$ for $x\ge 10^{-3}$, the combined $d{\sigma }^{AA\to J/\psi AA}/dy$ and ${\sigma }^{\gamma A\to J/\psi A}(W_{\gamma p})$ data allow us to determine $S_{Pb}(x)$ in the wide interval $10^{-5}<x<0.05$. In particular, the data favor $S_{Pb}(x)$, which decreases with a decrease of $x$ in the $10^{-4}<x<0.01$ interval, and can be both decreasing or constant for $x<10^{-4}$. Identifying $S_{Pb}(x)$ with the ratio of the gluon distributions in Pb and the proton $R_g(x,Q_0^2)=g_A(x,Q_0^2)/[A{g}_p(x,Q_0^2)]$, we demonstrate that the leading twist approximation (LTA) for nuclear shadowing provides a good description of all the data on $d{\sigma }^{AA\to J/\psi AA}/dy$ and ${\sigma }^{\gamma A\to J/\psi A}(W_{\gamma p})$ as well as on the experimental values for $S_{Pb}(x)$ derived from ${\sigma }^{\gamma A\to J/\psi A}(W_{\gamma p})$. We also show that modern nuclear PDFs reasonably reproduce $S_{Pb}(x)$ as well.

    hep-phhep-exnucl-exPRC(2024)·10 citations
11. 11*

    QCD analysis of $x{F}_3$ structure functions in deep-inelastic scattering: Mellin transform by Gegenbauer polynomial up to N${}^3$LO approximation

    Fatemeh Arbabifar🇮🇷 · Nader Morshedian🇮🇷 · Leila Ghasemzadeh🇮🇷 · Shahin Atashbar Tehrani🇮🇷

    This paper provides a thorough examination of the $x{F}_3$ structure functions in deep-inelastic scattering through a comprehensive QCD analysis. Our approach harnesses sophisticated mathematical techniques, namely the Mellin transform combined with Gegenbauer polynomials. We have employed the Jacobi polynomials approach for analysis, conducting investigations at three levels of precision: Next-to-Leading Order (NLO), Next-to-Next-to-Leading Order (N${}^2$LO), and Next-Next-Next-to-Leading Order (N${}^3$LO). We have performed a comparison of our sets of valence-quark parton distribution functions with those of recent research groups, specifically CT18 and MSHT20 at NLO and N${}^2$LO, and MSTH23 at N${}^3$LO, which are concurrent with our current analysis. The combination of Mellin transforms with Gegenbauer polynomials proves to be a powerful tool for investigating the $x{F}_3$ structure functions in deep-inelastic scattering and the results obtained from our analysis demonstrate a favorable alignment with experimental data.

    hep-phPRC(2024)·2 citations
12. 12*

    "Unification" of BSM Searches and SM Measurements: the case of lepton$+MET$ and $m_W$

    Kaustubh Agashe🇺🇸 · Sagar Airen🇺🇸 · Roberto Franceschini🇮🇹 · Doojin Kim🇺🇸 · Ashutosh V. Kotwal🇺🇸 · Lorenzo Ricci🇺🇸 · Deepak Sathyan🇺🇸

    We develop the idea that the unprecedented precision in Standard Model (SM) measurements, with further improvement at the HL-LHC, enables new searches for physics Beyond the Standard Model (BSM).As an illustration, we demonstrate that the measured kinematic distributions of the lepton$+MET$ final state not only determine the mass of the $W$ boson, but are also sensitive to light new physics. Such a search for new physics thus requires a simultaneous fit to the BSM and SM parameters, "unifying" searches and measurements at the LHC and Tevatron. In this paper, we complete the program initiated in our earlier work arXiv:2310.13687. In particular, we analyze ($i$) novel decay modes of the $W$ boson with a neutrinophilic invisible scalar or with a heavy neutrino; ($ii$) modified production of $W$ bosons, namely, associated with a hadrophilic invisible $Z^{\prime }$ gauge boson; and ($iii$) scenarios without an on-shell $W$ boson, such as slepton-sneutrino production in the Minimal Supersymmetric Standard Model (MSSM). Here, we complement our previous MSSM analysis in arXiv:2310.13687 by considering a different kinematic region. Our results highlight that new physics can still be directly discovered at the LHC, including light new physics,via SM precision measurements. Furthermore, we illustrate that such BSM signals are subtle, yet potentially large enough to affect the precision measurements of SM parameters themselves, such as the $W$ boson mass.

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

    Lorentz violating backgrounds from quadratic, shift-symmetric, ultralight dark matter

    Minyuan Jiang🇩🇪 · Benjamin D. Pecjak🇬🇧 · Gilad Perez🇮🇱 · Somasundaram Sankaranarayanan🇮🇱

    We consider an effective theory for a shift-symmetric, quadratically-coupled, ultralight spin-0 field. The leading CP-conserving interactions with Standard Model fields in the effective theory arise at dimension 8. We discuss the renormalization group evolution and positivity bounds on these operators, as well as their possible UV origins. Assuming that the spin-0 field is associated with an ultralight dark matter candidate, we discuss the effects of the dimension-8 operators on experiments searching for the oscillation of fundamental constants and Lorentz violation. We find that the direct bounds on these two effects are of similar strength but rather weak, corresponding to a UV cutoff scale of keV order, as they are mediated by dimension-8 operators.

    hep-phphysics.atom-phJHEP(2024)·5 citations
14. 14*

    Cosmology-independent Photon Mass Limits from Localized Fast Radio Bursts by using Artificial Neural Networks

    Jing-Yu Ran🇨🇳 · Bao Wang🇨🇳 · Jun-Jie Wei🇨🇳

    A hypothetical photon mass, $m_{\gamma }$, can produce a frequency-dependent vacuum dispersion of light, which leads to an additional time delay between photons with different frequencies when they propagate through a fixed distance. The dispersion measure--redshift measurements of fast radio bursts (FRBs) have been widely used to constrain the rest mass of the photon. However, all current studies analyzed the effect of the frequency-dependent dispersion for massive photons in the standard $\Lambda$CDM cosmological context. In order to alleviate the circularity problem induced by the presumption of a specific cosmological model based on the fundamental postulate of the masslessness of photons, here we employ a new model-independent smoothing technique, Artificial Neural Network (ANN), to reconstruct the Hubble parameter $H(z)$ function from 34 cosmic-chronometer measurements. By combining observations of 32 well-localized FRBs and the $H(z)$ function reconstructed by ANN, we obtain an upper limit of $m_{\gamma }\le 3.5\times 10^{-51}\mathrm{kg}$, or equivalently $m_{\gamma }\le 2.0\times 10^{-15}eV/{\mathrm{c}}^2$ ($m_{\gamma }\le 6.5\times 10^{-51}\mathrm{kg}$, or equivalently $m_{\gamma }\le 3.6\times 10^{-15}eV/{\mathrm{c}}^2$) at the $1\sigma$ ($2\sigma$) confidence level. This is the first cosmology-independent photon mass limit derived from extragalactic sources.

    ↳ astro-ph.COastro-ph.HEgr-qchep-phChin.Phys.Lett.(2024)·10 citations
15. 15*

    Bayesian and Principal Component Analyses of Neutron Star Properties

    N. K. Patra🇮🇳

    A Bayesian method is used in this extensive work to generate a large set of minimally constrained equations of state (EOSs) for matters in neutron stars (NS). These EOSs are analyzed for their correlations with key NS properties, such as the tidal deformability, radius, and maximum mass, within the mass range of $1.2-2M_{\odot }$. The observed connections between the pressure of $\beta$-equilibrated matter and the properties of neutron stars at different densities offer significant insights into the behavior of NS matter in a nearly model-independent manner. The study also examines the influence of various factors on the correlation of symmetry energy parameters, such as slope and curvature parameters at saturation density (${\rho }_0=0.16{\text{fm}}^{-3}$) with the tidal deformability and radius of neutron stars. This study investigates the robustness of the observed correlations by considering the distributions and interdependence of symmetry energy parameters. Furthermore, the utilization of Principal Component Analysis (PCA) is employed to unveil the complicated relationship between various nuclear matter parameters and properties of neutron stars. This analysis highlights the importance of employing multivariate analysis techniques in order to comprehend the variety in tidal deformability and radius observed across distinct masses of NS. This comprehensive study aims to establish a connection between the parameters of nuclear matter and the properties of neutron stars, providing significant insights into the behavior of NS matter across different circumstances.

    ↳ nucl-thastro-ph.HEastro-ph.SRgr-qc+10 citations
16. 16*

    Lens Stochastic Diffraction: A Signature of Compact Objects in Gravitational-Wave Data

    Miguel Zumalacárregui🇩🇪

    Every signal propagating through the universe is diffracted by the gravitational field of intervening objects, known as gravitational lenses. Diffraction is most efficient when caused by compact objects, which form additional images of any source. Although secondary images are typically too weak to stand out in the noise, they can be detected collectively using gravitational waves (GWs) by leveraging 1) knowledge of the primary signal and 2) scaling of the signal's strength with the angular offset. The ensemble of secondary signals constitutes \textit{lens stochastic diffraction} (LSD): correlated Poisson-distributed fluctuations following a GW event due to intervening compact objects. The amplitude and temporal distribution of these signals encode the abundance of the lenses, their mass spectrum and their density profiles. By including all secondary signals over all resolved GW events, LSD offers an improvement of $\sim 2.5$ orders of magnitude over the identification of individual lensed images, for objects with mass $M_l\gtrsim 10^3{M}_{\odot }$ and size $\lesssim 1\mathrm{pc}(M_l/10^4{M}_{\odot }{)}^{1/2}$. The framework generalizes to wave optics, where halos too diffuse to form images imprint localized features on the waveform. Developing data-analysis techniques will allow LSD to probe compact dark-matter halos and allow next-generation instruments to detect supermassive black holes, given the abundance expected from quasar luminosity studies.

    ↳ gr-qcastro-ph.COastro-ph.HEhep-ph20 citations
17. 17*

    Global Data-Driven Determination of Baryon Transition Form Factors

    Yu-Fei Wang🇩🇪 · Michael Döring🇺🇸 · Jackson Hergenrather🇺🇸 · Maxim Mai🇺🇸 · Terry Mart🇮🇩 · Ulf-G. Meißner🇩🇪 · Deborah Rönchen🇩🇪 · Ronald Workman (Jülich-Bonn-Washington Collaboration)🇺🇸

    Hadronic resonances emerge from strong interactions encoding the dynamics of quarks and gluons. The structure of these resonances can be probed by virtual photons parameterized in transition form factors. In this study, twelve $N^{\ast }$ and $\Delta$ transition form factors at the pole are extracted from data with the center-of-mass energy from $\pi N$ threshold to $1.8\mathrm{GeV}$, and the photon virtuality $0\le Q^2/{\mathrm{GeV}}^2\le 8$. For the first time, these results are determined from a simultaneous analysis of more than one state, i.e., $\sim 10^5$ $\pi N$, $\eta N$, and $K\Lambda$ electroproduction data. In addition, about $5\cdot 10^4$ data in the hadronic sector as well as photoproduction serve as boundary conditions. For the $\Delta (1232)$ and $N(1440)$ states our results are in qualitative agreement with previous studies, while the transition form factors at the poles of some higher excited states are estimated for the first time. Realistic uncertainties are determined by further exploring the parameter space.

    ↳ nucl-thhep-phnucl-exPRL(2024)·19 citations
18. 18*

    Decoherence in Neutrino Oscillation at the ESSnuSB Experiment

    ESSnuSB: J. Aguilar🇪🇸 · M. Anastasopoulos🇸🇪 · E. Baussan🇫🇷 · A.K. Bhattacharyya🇸🇪 · A. Bignami🇸🇪 · M. Blennow🇸🇪 · M. Bogomilov🇧🇬 · B. Bolling🇸🇪 · E. Bouquerel🇫🇷 · F. Bramati🇮🇹 · A. Branca🇮🇹 · G. Brunetti🇮🇹 and 83 other authors

    Neutrino oscillation experiments provide a unique window in exploring several new physics scenarios beyond the standard three flavour. One such scenario is quantum decoherence in neutrino oscillation which tends to destroy the interference pattern of neutrinos reaching the far detector from the source. In this work, we study the decoherence in neutrino oscillation in the context of the ESSnuSB experiment. We consider the energy-independent decoherence parameter and derive the analytical expressions for P${}_{\mu e}$ and P${}_{\mu \mu }$ probabilities in vacuum. We have computed the capability of ESSnuSB to put bounds on the decoherence parameters namely, ${\Gamma }_{21}$ and ${\Gamma }_{32}$ and found that the constraints on ${\Gamma }_{21}$ are competitive compared to the DUNE bounds and better than the most stringent LBL ones from MINOS/MINOS+. We have also investigated the impact of decoherence on the ESSnuSB measurement of the Dirac CP phase ${\delta }_{\mathrm{CP}}$ and concluded that it remains robust in the presence of new physics.

    ↳ hep-exhep-phJHEP(2024)·25 citations
19. 19*

    False Vacuum Decay Rate From Thin To Thick Walls

    Marco Matteini🇸🇮 · Miha Nemevšek🇸🇮 · Yutaro Shoji🇸🇮 · Lorenzo Ubaldi🇸🇮

    We consider a single real scalar field in flat spacetime with a polynomial potential up to ${\varphi }^4$, that has a local minimum, the false vacuum, and a deeper global minimum, the true vacuum. When the vacua are almost degenerate we are in the thin wall regime, while as their difference in potential energy increases, we approach the thick wall regime. We give explicit simple formulae for the decay rate of the false vacuum in 3 and 4 spacetime dimensions. Our results include a careful treatment both of the bounce action, which enters at the exponent of the decay rate, and of the functional determinant at one loop, which determines the prefactor. The bounce action is computed analytically as an expansion in the thin wall parameter in generic $D$ dimensions. We find that truncating such an expansion at second order we obtain a remarkably accurate bounce action also deep into thick wall regimes. We calculate the functional determinant numerically in 3 and 4 dimensions and fit the results with simple polynomials of the same thin wall parameter. This allows us to write the complete one-loop decay rate as a compact expression, which works accurately from thin to thick wall regimes.

    ↳ hep-thhep-phJHEP(2025)·26 citations
20. 20*

    Measurement of Milli-Charged Particles with a moderately large cross section from the Earth's core at IceCube

    Ye Xu🇨🇳

    It is assumed that heavy dark matter $\varphi$ with O(TeV) mass captured by the Earth may decay to relativistic light milli-charged particles (MCPs). These MCPs could be measured by the IceCube neutrino telescope. The massless hidden photon model was taken for MCPs to interact with nuclei, so that the numbers and fluxes of expected MCPs may be evaluated at IceCube. Meanwhile, the numbers of expected neutrino background events were also evaluated at IceCube. Based on the assumption that no events are observed at IceCube in 10 years, the corresponding upper limits on MCP fluxes were calculated at 90\% C. L.. These results indicated that the MCPs from the Earth's core could be directly detected at O(1TeV) energies at IceCube when $2\times 10^{-5}\lesssim {ϵ}^2\lesssim 4.5\times 10^{-3}$. And a new region of 100 MeV < $m_{MCP}$ < 10 GeV and $4.47\times 10^{-3}$ $\lesssim$ $ϵ$ $\lesssim$ $9.41\times 10^{-2}$ is ruled out in the $m_{MCP}$-$ϵ$ plane with 10 years of IceCube data.

    ↳ astro-ph.HEhep-phJHEP(2024)·2 citations
21. 21*

    Cosmological test of an ultraviolet origin of Dark Energy

    Hans Christiansen · Bence Takács · Steen H. Hansen

    The accelerated expansion of the Universe is impressively well described by a cosmological constant. However, the observed value of the cosmological constant is much smaller than expected based on quantum field theories. Recent efforts to achieve consistency in these theories have proposed a relationship between Dark Energy and the most compact objects, such as black holes (BH). However, experimental tests are very challenging to devise and perform. In this article, we present a testable model with no cosmological constant, in which the accelerated expansion can be driven by black holes. The model couples the expansion of the Universe (the Friedmann equation) with the mass-function of cosmological haloes (using the Press-Schechter formalism). Through the observed link between halo-masses and BH-masses one thus gets a coupling between the expansion rate of the Universe and the BHs. We compare the predictions of this simple BH model with SN1a data and find a poor agreement with observations. Our method is sufficiently general that it allows us to also test a fundamentally different model, also without a cosmological constant, where the accelerated expansion is driven by a new force proportional to the internal velocity dispersion of galaxies. Surprisingly enough this model cannot be excluded using the SN1a data.

    ↳ astro-ph.COhep-phUniverse(2024)·1 citation

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.