Tue·Jun 13, 2023Tuesday·June 13, 2023

1. 01*

   Identification of newly observed singly charmed baryons using relativistic flux tube model

   Pooja Jakhad🇮🇳 · Juhi Oudichhya🇮🇳 · Keval Gandhi🇮🇳 · Ajay Kumar Rai🇮🇳

   We calculate the mass spectra of ${\Lambda }_c$, ${\Xi }_c$, ${\Sigma }_c$, ${\Xi }_c^{{}^{\prime }}$, and ${\Omega }_c$ baryons in the framework of quark-diquark configuration using relativistic flux tube model. The spin-dependent interactions are included in the j-j coupling scheme to find complete mass spectra. We satisfactorily describe the known singly charmed baryons in quark-diquark configuration. The possible spin-parity $J^P$ quantum numbers are assigned to several experimentally observed states. Furthermore, some useful mass predictions are given for more excited states that are reasonably consistent with other model predictions for lower excited states. {From the obtained results the Regge trajectories for these singly charmed baryons are constructed in the ($J,M^2$) plane and the properties like linearity, parallelism and equidistant are verified.} Also, these predictions should be tested in future experiments.

   hep-phPRD(2023)·48 citations
2. 02*

   Are the $a_0(1710)$ or $a_0(1817)$ resonances in the $D_s^{+}\to K_S^0{K}^{+}{\pi }^0$ decay?

   Zhong-Yu Wang🇨🇳 · Yu-Wen Peng🇨🇳 · Jing-Yu Yi🇨🇳 · W. C. Luo🇨🇳 · C. W. Xiao🇨🇳

   The BESIII Collaboration claimed that a new $a_0(1817)$ resonance was found in the recent results of the $D_s^{+}\to K_S^0{K}^{+}{\pi }^0$ decay. For this decay process, we perform a unitary amplitude to analyze the contributions of the states $a_0(980{)}^{+}$ and $a_0(1710{)}^{+}$ with the final state interactions. Considering the Cabibbo-favored external and internal $W$-emission mechanisms at the quark level, and the contributions of the resonances $a_0(980{)}^{+}$, $a_0(1710{)}^{+}$ in the $S$-wave and ${\bar{K}}^{\ast }(892{)}^0$, $K^{\ast }(892{)}^{+}$ in the $P$-wave, the recent experimental data of the $K_S^0{K}^{+}$ invariant mass spectrum from the BESIII Collaboration can be described well. In our results, the states $a_0(980)$ and $a_0(1710)$ are dynamically generated from the final state interactions of $K\bar{K}$ and $K^{\ast }{\bar{K}}^{\ast }$, respectively, which support the molecular nature for them. Moreover, some obtained branching fractions are in agreement with the experimental measurements.

   hep-phPRD(2023)·15 citations
3. 03*

   Study of the nonleptonic charmless $B$ $\to$ $SS$ decays with the QCD factorization approach

   Lili Chen🇨🇳 · Mengfei Zhao🇨🇳 · Liting Wang🇨🇳 · Yueyang Kang🇨🇳 · Qin Chang🇨🇳 · Junfeng Sun🇨🇳

   Inspired by the brilliant prospects of the ongoing $B$ meson experiments, the hadronic charmless $B$ $\to$ $SS$ decays are studied by considering the next-to-leading (NLO) contributions with the QCD factorization approach, where $S$ denotes the scalar mesons $K_0^{\ast }(1430)$ and $a_0(1450)$. Branching ratios and $CP$ violating asymmetries are estimated with the updated values of hadronic parameters obtained from a covariant light-front quark model, for two scenarios where the scalar mesons are the $1^3{P}_0$ and $2^3{P}_0$ states. It is found that the NLO contributions are very important for the $B$ $\to$ $SS$ decays; For the $B$ $\to$ $a_0(1450)K_0^{\ast }(1430)$ and $B_s$ $\to$ $K_0^{\ast }(1430){\overline{K}}_0^{\ast }(1430)$ decays, branching ratios can reach up to the order of $\mathcal{O}(10^{-5})$ by assuming that the scalar mesons are the $1P$ states, and should first be investigated in the future experiments.

   hep-phEPJC(2023)·5 citations
4. 04*

   Astrophysically sourced quantum coherent photonic signals

   Arjun Berera🇬🇧 · Jaime Calderón-Figueroa🇬🇧 · Liang Chen🇨🇳 · Thomas W. Kephart🇺🇸

   Stimulated emission is shown to be robust in stars. Through Bose enhancement this produces quantum states of aligned, monochromatic photons similar to a laser. The probability of creating such states is computed. We show that from the solar corona such quantum states would propagate outside of the solar region and through the Solar System without decoherence. For a $1{\mathrm{m}}^2$ detector at the distance of the Earth from the Sun we estimate rates of such quantum states in the few per second thus potentially detectable. The same process should lead to such quantum states also arriving from stars at interstellar distances.

   hep-phastro-ph.SRquant-phPRD(2023)·3 citations
5. 05*

   The strong decay of $Y(4230)\to J/\psi f_0(980)$ in light cone sum rules

   Yiling Xie🇨🇳 · Hao Sun🇨🇳

   In this work, we assign the tetraquark state for $Y(4230)$ resonance, and investigate the mass and decay constant of $Y(4230)$ in the framework of SVZ sum rules through a different calculation technique. Then we calculate the strong coupling $g_{YJ/\psi f_0}$ by considering soft-meson approximation techniques, within the framework of light cone sum rules. And we use strong coupling $g_{YJ/\psi f_0}$ to obtain the width of the decay $Y(4230)\to J/\psi f_0(980)$. Our prediction for the mass is in agreement with the experimental measurement, and that for the decay width of $Y(4230)\to J/\psi f_0(980)$ is within the upper limit.

   hep-phCPC(2024)·1 citation
6. 06*

   QCD with an Infrared Fixed Point -- Pion Sector

   Roman Zwicky🇬🇧

   The possibility that gauge theories with chiral symmetry breaking below the conformal window exhibit an infrared fixed point is explored. With this assumption three aspects of pion physics are reproduced if the the quark mass anomalous dimension at the infrared fixed point is ${\gamma }_{\ast }=1$: First, by matching the long-distance scalar adjoint correlation function. Second, by perturbing the fixed point by a small quark mass, the $m_q$-dependence of the pion mass is reproduced by renormalisation group arguments. Third, consistency of the trace anomaly and the Feynman-Hellmann theorem, for small $m_q$, imply the same result once more. This suggests the following picture for the conformal window: close to its upper boundary ${\gamma }_{\ast }$ is zero and grows as the number of fermions is reduced until its lower boundary ${\gamma }_{\ast }=1$ is reached, where chiral symmetry breaking sets in. Below, the strongly coupled gauge theory with ${\gamma }_{\ast }=1$ is infrared dual to the free theory of pions. A possible dilaton sector of the scenario will be addressed in a companion paper.

   hep-phhep-lathep-thPRD(2024)·35 citations
7. 07*

   Electron and Muon Anomalous Magnetic Moment in the ${\mathbb{Z}}_3$-NMSSM

   Junjie Cao🇨🇳 · Lei Meng🇨🇳 · Yuanfang Yue🇨🇳

   Inspired by the recent measurements of the muon and electron anomalous magnetic moments, the rapid progress of the LHC search for supersymmetry, and the significantly improved sensitivities of dark matter direct detection experiments, we studied the supersymmetric contribution to the electron $g-2$, $a_e^{\mathrm{SUSY}}$, in the Next-to-Minimal Supersymmetric Standard Model with a discrete ${\mathbb{Z}}_3$ symmetry. We concluded that $a_e^{\mathrm{SUSY}}$ was mainly correlated with $a_{\mu }^{\mathrm{SUSY}}$ by the formula $a_e^{\mathrm{SUSY}}/m_e^2\simeq a_{\mu }^{\mathrm{SUSY}}/m_{\mu }^2$, and significant violations of this correlation might occur only in rare cases. As a result, $a_e^{\mathrm{SUSY}}$ was typically around $5\times 10^{-14}$ when $a_{\mu }^{\mathrm{SUSY}}\simeq 2.5\times 10^{-9}$. We also concluded that the dark matter direct detection and LHC experiments played crucial roles in determining the maximum reach of $a_e^{\mathrm{SUSY}}$. Concretely, $a_e^{\mathrm{SUSY}}$ might be around $3\times 10^{-13}$ in the optimum cases if one used the XENON-1T experiment to limit the supersymmetry parameter space. This prediction, however, was reduced to $1.5\times 10^{-13}$ after implementing the LZ restrictions and $1.0\times 10^{-13}$ when further considering the LHC restrictions.

   hep-phPRD(2023)·19 citations
8. 08*

   Probing top quark anomalous moments in $W$ boson associated single top quark production at the LHC using polarization and spin correlation

   Rafiqul Rahaman🇮🇳 · Amir Subba🇮🇳

   We study the $W$ boson associated single top quark production at the Large Hadron Collider (LHC) to probe anomalous chromo-magnetic and chromo-electric moments of the top quark with the help of polarization and spin correlation observables besides the cross-section in the leptonic final state. We reconstruct the two neutrinos in the final state using the $M_{T2}$ assisted on-shell (MAOS) reconstruction method to measure the polarization and spin correlation asymmetries of the top quark and the $W$ boson. We estimate the limits on the anomalous moments in a detector-level simulation considering possible backgrounds for a few sets of integrated luminosities and examined the effect of systematic uncertainties.

   hep-phPRD(2023)·4 citations
9. 09*

   Doubly-heavy tetraquark at finite temperature in a holographic model

   Xi Guo · Jia-Jie Jiang · Xuan Liu · Dong Xiang · Xun Chen

   In this paper, we employ gauge/gravity duality to investigate the string breaking and melting of doubly-heavy tetraquark that includes two heavy quarks and two light antiquarks in a holographic model at finite temperature. Firstly, we investigate four configurations of $\mathrm{QQ}\bar{\mathrm{q}}\bar{\mathrm{q}}$ in the confined phase and consider different separation distances of the heavy quarks at varying temperatures. At high temperature, $\mathrm{QQ}\bar{\mathrm{q}}\bar{\mathrm{q}}$ melts at certain distances and the confined quarks are released. As the temperature continues to increase, some configurations of doubly-heavy tetraquark can not exist. Furthermore, we investigate three decay modes of $\mathrm{QQ}\bar{\mathrm{q}}\bar{\mathrm{q}}$ and compare the potential energy of $\mathrm{QQ}\bar{\mathrm{q}}\bar{\mathrm{q}}$ with that of $\mathrm{QQq}$ at finite temperature .

   hep-phEPJC(2024)·6 citations
10. 10*

    CP-violating axion interactions II: axions as Dark Matter

    Vaisakh Plakkot🇳🇱 · Wouter Dekens🇺🇸 · Jordy de Vries🇳🇱 · Sachin Shain🇳🇱

    Axions provide a solution to the strong CP problem and are excellent dark matter candidates. The presence of additional sources of CP violation, for example to account for the matter/antimatter asymmetry of the universe, can lead to CP-violating interactions between axions and Standard Model fields. In case axions form a coherent dark matter background, this leads to time-oscillating fundamental constants such as the fine-structure constant and particle masses. In this work we compare the sensitivity of various searches for CP-odd axion interactions. These include fifth-force experiments, searches for time-oscillating constants induced by axion dark matter, and direct limits from electric dipole moment experiments. We show that searches for oscillating constants can outperform fifth-force experiments in the regime of small axion masses, but, in general, do not reach the sensitivity of electric dipole moment experiments.

    hep-phphysics.atom-phJHEP(2023)·13 citations
11. 11*

    Unfolding Particle Physics Hierarchies with Supersymmetry and Extra Dimensions

    Raman Sundrum🇺🇸

    This is a written version of lectures delivered at TASI 2022 ``Ten Years After the Higgs Discovery: Particle Physics Now and Future''. Mechanisms and symmetries beyond the Standard Model (BSM) are presented capable of elegantly and robustly generating the striking hierarchies we observe in particle physics. They are shown to be among the central archetypes of quantum effective field theory and to strongly resonate with the tight structure and phenomenology of the Standard Model itself, allowing one to motivate, develop and test a worthy successor. The (Little) Hiearchy Problem is discussed within this context. The lectures culminate in specific BSM case-studies, gaugino-mediated (dynamical) supersymmetry breaking to generate the weak/Planck hierarchy, and (in less detail) extra-dimensional wavefunction overlaps to generate flavor hierarchies.

    hep-phPoS(2024)·4 citations
12. 12*

    Muon accelerators -- Muon lifetime measurements as window to Planck scale physics

    Iarley P. Lobo🇧🇷 · Christian Pfeifer🇩🇪

    A prominent effective description of particles interacting with the quantum properties of gravity is through modifications of the general relativistic dispersion relation. Such modified dispersion relations lead to modifications in the relativistic time dilation. A perfect probe for this effect, which goes with the particle energy cubed $E^3$ over the quantum gravity scale $E_{\text{QG}}$ and the square of the particle mass $M^2$ would be a very light unstable particle for which one can detect the lifetime in the laboratory as a function of its energy to very high precision. In this article we conjecture that a muon collider or accelerator would be a perfect tool to investigate the existence of an anomalous time dilation, and with it the fundamental structure of spacetime at the Planck scale.

    hep-phClass.Quant.Grav.(2024)·4 citations
13. 13*

    Impact of electron shell excitations on the energy spectrum of $\beta$-electrons in neutrinoless double-$\beta$ decay

    M.I. Krivoruchenko🇷🇺 · K.S. Tyrin🇷🇺 · F.F. Karpeshin🇷🇺

    The electron shell of the daughter atoms often appears excited in the double-$\beta$ decays, which causes a change in the energy taken away by $\beta$-electrons. The average value and variance of the excitation energy of the electron shell of the daughter atom are calculated for the double-$\beta$ decay of germanium ${}_{32}^{76}\mathrm{Ge}{\to }_{34}^{76}{\mathrm{Se}}^{\ast }+2{\beta }^{-}(+2\overline{{\nu }_e})$ in both the Thomas--Fermi model and the relativistic Dirac--Hartree--Fock theory. Using the results obtained, a two-parameter model of the energy spectrum of $\beta$-electrons in the neutrinoless mode is constructed, taking into account reaction energy redistribution in the decay channels. The shift in total energy of $\beta$-electrons is found to be under 50 eV at a confidence level of 90%. The average excitation energy, on the other hand, is an order of magnitude higher and equal to $\sim 400$ eV, while the square root of the variance is equal to $\sim 2900$ eV, which is presumably explained by the contribution of the core electrons to the energy characteristics of the process. The probability is nearly saturated with excitations with a small amount of released energy, which is common for the outermost electrons. The distortion of the peak shape of the neutrinoless double-$\beta$ decay should be taken into consideration when analyzing data from detectors with a resolution of $\sim 100$ eV or higher.

    hep-phZh.Eksp.Teor.Fiz.(2023)·0 citations
14. 14*

    Probing Exotic Phases Via Stochastic Gravitational Wave Spectra

    Joshua Berger🇺🇸 · Amit Bhoonah🇺🇸 · Biswajit Padhi🇺🇸

    Stochastic backgrounds of gravitational waves (GWs) from the pre-BBN era offer a unique opportunity to probe the universe beyond what has already been achieved with the Cosmic Microwave Background (CMB). If the source is short in duration, the low frequency tail of the resulting GW spectrum follows a universal frequency scaling dependent on the equation of state of the universe when modes enter the horizon. We demonstrate that the distortion of the equation of state due to massive particles becoming non-relativistic can lead to an observable dip in the GW spectrum. To illustrate this effect, we consider a first order chiral symmetry breaking phase transition in the weak-confined Standard Model (WCSM). The model features a large number of pions and mostly elementary fermions with masses just below the critical temperature for the phase transition. These states lead to a 20$\%$ dip in the GW power. We find potential sensitivity to the distortions in the spectrum to future GW detectors such as LISA, DECIGO, BBO, and $\mu$Ares.

    hep-phJCAP(2024)·2 citations
15. 15*

    Flavoured jets with exact anti-$k_t$ kinematics and tests of infrared and collinear safety

    Fabrizio Caola🇬🇧 · Radosław Grabarczyk🇬🇧 · Maxwell L. Hutt🇬🇧 · Gavin P. Salam🇬🇧 · Ludovic Scyboz🇬🇧 · Jesse Thaler🇺🇸

    We propose extensions of the anti-$k_t$ and Cambridge/Aachen hierarchical jet clustering algorithms that are designed to retain the exact jet kinematics of these algorithms, while providing an infrared-and-collinear-safe definition of jet flavour at any fixed order in perturbation theory. Central to our approach is a new technique called Interleaved Flavour Neutralisation (IFN), whereby the treatment of flavour is integrated with, but distinct from, the kinematic clustering. IFN allows flavour information to be meaningfully accessed at each stage of the clustering sequence, which enables a consistent assignment of flavour both to individual jets and to their substructure. We validate the IFN approach using a dedicated framework for fixed-order tests of infrared and collinear safety, which also reveals unanticipated issues in earlier approaches to flavoured jet clustering. We briefly explore the phenomenological impact of IFN with anti-$k_t$ jets for benchmark tasks at the Large Hadron Collider.

    hep-phhep-exPRD(2023)·68 citations
16. 16*

    Heavy Neutral Leptons from Stopped Muons and Pions

    Yohei Ema🇺🇸 · Zhen Liu🇺🇸 · Kun-Feng Lyu🇺🇸 · Maxim Pospelov🇺🇸

    Stopped muons, which are generic in pion-at-rest experiments, can shed light on heavy neutral leptons (HNLs) in unexplored parameter spaces. If the HNL is lighter than the muon, the HNL can be produced from decays of muons and pions.The HNL will travel from the production location and decay into visible Standard Model (SM) modes, leaving signals inside downstream detectors. We find that in the case that the HNL dominantly mixes with muon neutrinos, the LSND constraint on the mixing angle squared is stronger than all the previous constraints by more than an order of magnitude. In this study, we recast the LSND measurement of the $\nu -e$ scattering. Future experiments such as PIP2-BD could further improve the sensitivity, provided they can distinguish the HNL events from backgrounds induced by the SM neutrinos.

    hep-phhep-exJHEP(2023)·15 citations
17. 17*

    The ABC of RPV: Classification of R-Parity Violating Signatures at the LHC for Small Couplings

    Herbi K. Dreiner🇩🇪 · Yong Sheng Koay🇸🇪 · Dominik Köhler🇩🇪 · Víctor Martín Lozano🇪🇸 · Javier Montejo Berlingen🇪🇸 · Saurabh Nangia🇩🇪 · Nadja Strobbe🇺🇸

    We perform a classification of all potential supersymmetric $R$-parity violating signatures at the LHC to address the question: are existing bounds on supersymmetric models robust, or are there still signatures not covered by existing searches, allowing LHC-scale supersymmetry to be hiding? We analyze all possible scenarios with one dominant RPV trilinear coupling at a time, allowing for arbitrary LSPs and mass spectra. We consider direct production of the LSP, as well as production via gauge-cascades, and find 6 different experimental signatures for the $LL\bar{E}$-case, 6 for the $LQ\bar{D}$-case, and 5 for the $\bar{U}\bar{D}\bar{D}$-case; together these provide complete coverage of the RPV-MSSM landscape. This set of signatures is confronted with the existing searches by \texttt{ATLAS} and \texttt{CMS}. We find all signatures have been covered at the LHC, although not at the sensitivity level needed to probe the direct production of all LSP types. For the case of a dominant $LL\bar{E}$-operator, we use \texttt{CheckMATE} to quantify the current lower bounds on the supersymmetric masses and find the limits to be comparable to or better than the $R$-parity conserving case. Our treatment can be easily extended to scenarios with more than one non-zero RPV coupling.

    hep-phhep-exJHEP(2023)·32 citations
18. 18*

    Homogeneous linear intrinsic constraints in the stationary manifold of a $G$-invariant potential

    R. Krishnan🇮🇳

    Given a $G$-invariant potential $\mathcal{V}$ of a scalar multiplet $\phi$, there may exist a set of homogenous linear equations that constrain the components of a stationary point of $\mathcal{V}$ independently of the coefficients of the terms in $\mathcal{V}$. We call them homogeneous linear intrinsic constraints (HLICs). HLICs in a stationary point manifest as HLICs in the corresponding vacuum alignment of $\phi$, which plays a central role in predictive phenomenological models. We discover that a group $\tilde{H}$ generates HLICs if the terms in $\mathcal{V}$ satisfy a condition, which we call the compatibility condition. In this paper, we also develop a procedure, which involves splitting $\mathcal{V}$ into smaller parts, to establish the existence of specific stationary points using arguments based on symmetries without the need for explicitly extremizing the potential. Using this procedure, we obtain $\tilde{H}$ as a direct product of the symmetry groups associated with the various irreducible multiplets (irreps) in $\phi$. This results from considering the potentials of the irreps separately and verifying if the cross terms are compatible with $\tilde{H}$.

    hep-phhep-thmath-phmath.MP2 citations
19. 19*

    Cosmic string gravitational waves from global $U(1{)}_{B-L}$ symmetry breaking as a probe of the type I seesaw scale

    Bowen Fu🇬🇧 · Anish Ghoshal🇵🇱 · Steve King🇬🇧

    In type I seesaw models, the right-handed neutrinos are typically super-heavy, consistent with the generation of baryon asymmetry via standard leptogenesis. Primordial gravitational waves of cosmological origin provides a new window to probe such high scale physics, which would otherwise be inaccessible. By considering a {\em global} $U(1{)}_{B-L}$ extension of the type I seesaw model, we explore the connection between the heaviest right-handed neutrino mass and primordial gravitational waves arising from the dynamics of global cosmic string network. As a concrete example, we study a global $U(1{)}_{B-L}$ extension of the Littlest Seesaw model, and show that the inevitable GW signals, if detectable, probe the parameter space that can accommodate neutrino oscillation data and successful leptogenesis, while respecting theoretical constraints like perturbativity of the theory. Including CMB constraints from polarization and dark radiation leaves a large region of parameter space of the model, including the best fit regions, which can be probed by GW detectors like LISA and ET in the near future. In general, the GW detectors can test high scale type I seesaw models with the heaviest right-handed neutrino mass above $2.5\times 10^{14}$ GeV, assuming the perturbativity, and $7\times 10^{13}$ GeV assuming that the coupling between the heaviest right-handed neutrino and the $U(1{)}_{B-L}$ breaking scalar is less than unity.

    hep-phastro-ph.COJHEP(2023)·29 citations
20. 20*

    Isospin Equilibration in Neutron Star Mergers

    Mark G. Alford🇺🇸 · Alexander Haber🇺🇸 · Ziyuan Zhang🇺🇸

    We analyze the isospin equilibration properties of neutrinoless nuclear ($npe$) matter in the temperature and density range that is relevant to neutron star mergers. Our analysis incorporates neutrino-transparency corrections to the isospin (``beta'') equilibrium condition which become noticeable at $T\gtrsim 1$MeV. We find that the isospin relaxation rate rises rapidly as temperature rises, and at $T\approx 5$MeV it is comparable to the timescale of the density oscillations that occur immediately after the merger. This produces a resonant peak in the bulk viscosity at $T\approx 5$MeV, which causes density oscillations to be damped on the timescale of the merger. Our calculations suggest that isospin relaxation dynamics may also be relevant when neutrinos are treated more accurately via neutrino transport schemes.

    ↳ nucl-thastro-ph.HEgr-qchep-phPRC(2024)·40 citations
21. 21*

    Evidence against a strong first-order phase transition in neutron star cores: impact of new data

    Len Brandes🇩🇪 · Wolfram Weise🇩🇪 · Norbert Kaiser🇩🇪

    With the aim of exploring the evidence for or against phase transitions in cold and dense baryonic matter, the inference of the sound speed and equation-of-state for dense matter in neutron stars is extended in view of recent new observational data. The impact of the heavy (2.35 $M_{\odot }$) black widow pulsar PSR J0952-0607 and of the unusually light supernova remnant HESS J1731-347 is inspected. In addition a detailed re-analysis is performed of the low-density constraint based on chiral effective field theory and of the perturbative QCD constraint at asymptotically high densities, in order to clarify the influence of these constraints on the inference procedure. The trace anomaly measure, $\Delta =1/3-P/\epsilon$, is also computed and discussed. A systematic Bayes factor assessment quantifies the evidence (or non-evidence) of low averaged sound speeds $(c_s^2\le 0.1)$, a prerequisite for a phase transition, within the range of densities realized in the core of neutron stars. One of the consequences of including PSR J0952-0607 in the data base is a further stiffening of the equation-of-state, resulting for a 2.1 solar-mass neutron star in a reduced central density of less than five times the equilibrium density of normal nuclear matter at the 68\% level. The evidence against small sound speeds in neutron star cores is further strengthened. Within the inferred 68\% posterior credible bands, only a weak first-order phase transition with a coexistence density interval $\Delta n/n\lesssim 0.2$ would be compatible with the observed data.

    ↳ nucl-thastro-ph.HEgr-qchep-ph+1PRD(2023)·92 citations
22. 22*

    Lattice Calculation of the Intrinsic Soft Function and the Collins-Soper Kernel

    Lattice Parton Collaboration · Min-Huan Chu · Jin-Chen He · Jun Hua · Jian Liang · Xiangdong Ji · Andreas Schäfer · Hai-Tao Shu · Yushan Su · Lisa Walter · Wei Wang · Ji-Hao Wang and 3 other authors

    We calculate the soft function using lattice QCD in the framework of large momentum effective theory incorporating the one-loop perturbative contributions. The soft function is a crucial ingredient in the lattice determination of light cone objects using transverse-momentum-dependent (TMD) factorization. It consists of a rapidity-independent part called intrinsic soft function and a rapidity-dependent part called Collins-Soper kernel. We have adopted appropriate normalization when constructing the pseudo-scalar meson form factor that is needed in the determination of the intrinsic part and applied Fierz rearrangement to suppress the higher-twist effects. In the calculation of CS kernel we consider a CLS ensemble other than the MILC ensemble used in a previous study. We have also compared the applicability of determining the CS kernel using quasi TMDWFs and quasi TMDPDFs. As an example, the determined soft function is used to obtain the physical TMD wave functions (WFs) of pion and unpolarized iso-vector TMD parton distribution functions (PDFs) of proton.

    ↳ hep-lathep-exhep-phJHEP(2023)·64 citations
23. 23*

    $\Delta I=3/2$ and $\Delta I=1/2$ channels of $K\to \pi \pi$ decay at the physical point with periodic boundary conditions

    Thomas Blum🇺🇸 · Peter A. Boyle🇺🇸 · Daniel Hoying🇨🇭 · Taku Izubuchi🇺🇸 · Luchang Jin🇺🇸 · Chulwoo Jung🇺🇸 · Christopher Kelly🇺🇸 · Christoph Lehner🇩🇪 · Amarjit Soni🇺🇸 · Masaaki Tomii🇺🇸

    We present a lattice calculation of the $K\to \pi \pi$ matrix elements and amplitudes with both the $\Delta I=3/2$ and 1/2 channels and ${\epsilon }^{\prime }$, the measure of direct $CP$ violation. We use periodic boundary conditions (PBC), where the correct kinematics of $K\to \pi \pi$ can be achieved via an excited two-pion final state. To overcome the difficulty associated with the extraction of excited states, our previous work \cite{Bai:2015nea,RBC:2020kdj} successfully employed G-parity boundary conditions, where pions are forced to have non-zero momentum enabling the $I=0$ two-pion ground state to express the on-shell kinematics of the $K\to \pi \pi$ decay. Here instead we overcome the problem using the variational method which allows us to resolve the two-pion spectrum and matrix elements up to the relevant energy where the decay amplitude is on-shell. In this paper we report an exploratory calculation of $K\to \pi \pi$ decay amplitudes and ${\epsilon }^{\prime }$ using PBC on a coarser lattice size of $24^3\times 64$ with inverse lattice spacing $a^{-1}=1.023$ GeV and the physical pion and kaon masses. The results are promising enough to motivate us to continue our measurements on finer lattice ensembles in order to improve the precision in the near future.

    ↳ hep-lathep-phPRD(2023)·25 citations
24. 24*

    Dynamics of the $O(4)$ critical point in QCD: critical pions and diffusion in Model G

    Adrien Florio🇺🇸 · Eduardo Grossi🇮🇹 · Derek Teaney🇺🇸

    We present a detailed study of the finite momentum dynamics of the $O(4)$ critical point of QCD, which lies in the dynamic universality class of Model G. The critical scaling of the model is analyzed in multiple dynamical channels. For instance, the finite momentum analysis allows us to precisely extract the pion dispersion curve below the critical point. The pion velocity is in striking agreement with the predictions relation and static universality. The pion damping rate and velocity are both consistent with the dynamical critical exponent $\zeta =3/2$ of Model G. Similarly, although the critical amplitude for the diffusion coefficient of the conserved $O(4)$ charges is small, it is clearly visible both in the restored phase and with finite explicit symmetry breaking, and its dynamical scaling is again consistent with $\zeta =3/2$. We determine a new set of universal dynamical critical amplitude ratios relating the diffusion coefficient to a suitably defined order parameter relaxation time. We also show that in a finite volume simulation, the chiral condensate diffuses on the coset manifold in a manner consistent with dynamical scaling, and with a diffusion coefficient that is determined by the transport coefficients of hydrodynamic pions. Finally, the amplitude ratios (together with other non-universal amplitudes also reported here) compile all relevant information for further studies of Model G both in and out of equilibrium.

    ↳ hep-lathep-phnucl-thPRD(2024)·25 citations
25. 25*

    Decoding Neutron Star Observations: Revealing Composition through Bayesian Neural Networks

    Valéria Carvalho🇵🇹 · Márcio Ferreira🇵🇹 · Tuhin Malik🇵🇹 · Constança Providência🇵🇹

    We exploit the great potential offered by Bayesian Neural Networks (BNNs) to directly decipher the internal composition of neutron stars (NSs) based on their macroscopic properties. By analyzing a set of simulated observations, namely NS radius and tidal deformability, we leverage BNNs as effective tools for inferring the proton fraction and sound speed within NS interiors. To achieve this, several BNNs models were developed upon a dataset of $\sim$ 25K nuclear EoS within a relativistic mean-field framework, obtained through Bayesian inference that adheres to minimal low-density constraints. Unlike conventional neural networks, BNNs possess an exceptional quality: they provide a prediction uncertainty measure. To simulate the inherent imperfections present in real-world observations, we have generated four distinct training and testing datasets that replicate specific observational uncertainties. Our initial results demonstrate that BNNs successfully recover the composition with reasonable levels of uncertainty. Furthermore, using mock data prepared with the DD2, a different class of relativistic mean-field model utilized during training, the BNN model effectively retrieves the proton fraction and speed of sound for neutron star matter.

    ↳ nucl-thastro-ph.HEhep-phPRD(2023)·28 citations
26. 26*

    $\Lambda$ hypernuclear potentials beyond linear density dependence

    E. Friedman🇮🇱 · A. Gal🇮🇱

    In a recent paper [PLB 837 (2023) 137669] we showed that all measured ($1s_{\Lambda }$, $1p_{\Lambda }$) pairs of $\Lambda$ binding energies in $\Lambda$-hypernuclei across the periodic table, $12\le A\le 208$, can be obtained from a $\Lambda$-nucleus optical potential with only two adjustable $\Lambda N$ and $\Lambda NN$ parameters, associated with leading linear and quadratic terms in the nuclear density, derived by fitting ${}_{\Lambda }^{16}$N binding energies. Here we extend the previous analysis by performing least-squares fits to the full set of data points. Consequences of suppressing $\Lambda NN$ interactions between `core' nucleons and `excess' neutrons are studied and related predictions are made for ($1s_{\Lambda }$, $1p_{\Lambda }$) binding energies in ${}_{\Lambda }^{40,48}$K, obtainable from upcoming ${}^{40,48}$Ca($e,e^{\prime }{K}^{+}$) JLab experiments. We find $\Lambda$-nucleus partial potential depths of $D_{\Lambda }^{(2)}=-38.6\pm 0.8$~MeV ($\Lambda N$) and $D_{\Lambda }^{(3)}=11.3\pm 1.4$~MeV ($\Lambda NN$), with a total depth $D_{\Lambda }=-27.3\pm 0.6$~MeV at nuclear-matter density ${\rho }_0$=0.17~fm${}^{-3}$, consistently with our previous results. Extrapolation to higher nuclear densities and possible relevance to the `hyperon puzzle' in neutron-star matter are discussed.

    ↳ nucl-thhep-phnucl-exNPA(2023)·26 citations
27. 27*

    Infrared fixed point of the SU(3) gauge theory with $N_f=10$ flavors

    Anna Hasenfratz🇺🇸 · Ethan T. Neil🇺🇸 · Yigal Shamir🇮🇱 · Benjamin Svetitsky🇮🇱 · Oliver Witzel🇩🇪

    We use lattice simulations and the continuous renormalization-group method, based on the gradient flow, to calculate the $\beta$ function and anomalous dimensions of the SU(3) gauge theory with $N_f=10$ flavors of fermions in the fundamental representation. We employ several improvements to extend the range of available renormalized couplings, including the addition of heavy Pauli-Villars bosons to reduce cutoff effects and the combination of a range of gradient flow transformations. While in the weak coupling regime our result is consistent with those of earlier studies, our techniques allow us to study the system at much stronger couplings than previously possible. We find that the renormalization group $\beta$ function develops a zero, corresponding to an infrared-stable fixed point, at gradient-flow coupling $g^2=15.0(5)$. We also determine the mass and tensor anomalous dimensions: At the fixed point we find ${\gamma }_m\simeq 0.6$, suggesting that this system might be deep inside the conformal window.

    ↳ hep-lathep-phPRD(2023)·30 citations
28. 28*

    Additive Multi-Index Gaussian process modeling, with application to multi-physics surrogate modeling of the quark-gluon plasma

    Kevin Li · Simon Mak🇺🇸 · J.-F Paquet🇺🇸 · Steffen A. Bass🇺🇸

    The Quark-Gluon Plasma (QGP) is a unique phase of nuclear matter, theorized to have filled the Universe shortly after the Big Bang. A critical challenge in studying the QGP is that, to reconcile experimental observables with theoretical parameters, one requires many simulation runs of a complex physics model over a high-dimensional parameter space. Each run is computationally very expensive, requiring thousands of CPU hours, thus limiting physicists to only several hundred runs. Given limited training data for high-dimensional prediction, existing surrogate models often yield poor predictions with high predictive uncertainties, leading to imprecise scientific findings. To address this, we propose a new Additive Multi-Index Gaussian process (AdMIn-GP) model, which leverages a flexible additive structure on low-dimensional embeddings of the parameter space. This is guided by prior scientific knowledge that the QGP is dominated by multiple distinct physical phenomena (i.e., multiphysics), each involving a small number of latent parameters. The AdMIn-GP models for such embedded structures within a flexible Bayesian nonparametric framework, which facilitates efficient model fitting via a carefully constructed variational inference approach with inducing points. We show the effectiveness of the AdMIn-GP via a suite of numerical experiments and our QGP application, where we demonstrate considerably improved surrogate modeling performance over existing models.

    ↳ nucl-thcs.LGhep-phstat.ML1 citation
29. 29*

    Stochastic dynamics of multi-waterfall hybrid inflation and formation of primordial black holes

    Yuichiro Tada🇯🇵 · Masaki Yamada🇯🇵

    We show that a hybrid inflation model with multiple waterfall fields can result in the formation of primordial black hole (PBH) with an astrophysical size, by using an advanced algorithm to follow the stochastic dynamics of the waterfall fields. This is in contrast to the case with a single waterfall field, where the wavelength of density perturbations is usually too short to form PBHs of the astrophysical scale (or otherwise PBH are overproduced and the model is ruled out) unless the inflaton potential is tuned. In particular, we demonstrate that PBHs with masses of order $10^{20}\mathrm{g}$ can form after hybrid inflation consistently with other cosmological observations if the number of waterfall fields is about 5 for the case of instantaneous reheating. Observable gravitational waves are produced from the second-order effect of large curvature perturbations as well as from the dynamics of texture or global defects that form after the waterfall phase transition.

    ↳ astro-ph.COgr-qchep-phJCAP(2023)·29 citations
30. 30*

    Gauge theories and quantum gravity in a finite interval of time, on a compact space manifold

    Damiano Anselmi🇮🇹

    We study gauge theories and quantum gravity in a finite interval of time $\tau$, on a compact space manifold $\Omega$. The initial, final and boundary conditions are formulated in gauge invariant and general covariant ways by means of purely virtual extensions of the theories, which allow us to "trivialize" the local symmetries and switch to invariant fields (the invariant metric tensor, invariant quark and gluon fields, etc.). The evolution operator $U(t_{\text{f}},t_{\text{i}})$ is worked out diagrammatically for arbitrary initial and final states, as well as boundary conditions on $\partial \Omega$, and shown to be well defined and unitary for arbitrary $\tau =t_{\text{f}}-t_{\text{i}}<\infty$. We illustrate the basic properties in Yang-Mills theory on the cylinder.

    ↳ hep-thgr-qchep-phPRD(2024)·4 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.