Fri·May 19, 2023Friday·May 19, 2023

1. 01*

   The Photon Content of the Neutron

   Keping Xie🇺🇸 · Bei Zhou🇺🇸 · T.J. Hobbs🇺🇸

   In this work, we complete our CT18qed study with the neutron's photon parton distribution function (PDF), which is essential for the nucleus scattering phenomenology. Two methods, CT18lux and CT18qed, based on the LUXqed formalism and the DGLAP evolution, respectively, to determine the neutron's photon PDF have been presented. Various low-$Q^2$ non-perturbative variations have been carefully examined, which are treated as additional uncertainties on top of those induced by quark and gluon PDFs. The impacts of the momentum sum rule as well as isospin symmetry violation have been explored, and turn out to be negligible. A detailed comparison with other neutron's photon PDF sets has been performed, which shows a great improvement in the precision and a reasonable uncertainty estimation in our results. Finally, two phenomenological implications are demonstrated with photon-initiated processes: neutrino-nucleus $W$-boson production, which is important for the near-future TeV--PeV neutrino observations, and the axion-like particle production at a high-energy muon beam-dump experiment.

   hep-phastro-ph.HEnucl-thJHEP(2024)·32 citations
2. 02*

   Learning Likelihood Ratios with Neural Network Classifiers

   Shahzar Rizvi🇺🇸 · Mariel Pettee🇺🇸 · Benjamin Nachman🇺🇸

   The likelihood ratio is a crucial quantity for statistical inference in science that enables hypothesis testing, construction of confidence intervals, reweighting of distributions, and more. Many modern scientific applications, however, make use of data- or simulation-driven models for which computing the likelihood ratio can be very difficult or even impossible. By applying the so-called ``likelihood ratio trick,'' approximations of the likelihood ratio may be computed using clever parametrizations of neural network-based classifiers. A number of different neural network setups can be defined to satisfy this procedure, each with varying performance in approximating the likelihood ratio when using finite training data. We present a series of empirical studies detailing the performance of several common loss functionals and parametrizations of the classifier output in approximating the likelihood ratio of two univariate and multivariate Gaussian distributions as well as simulated high-energy particle physics datasets.

   hep-phphysics.data-anstat.APstat.MLJHEP(2024)·31 citations
3. 03*

   Primordial Black Hole Reheating

   Md Riajul Haque🇮🇳 · Essodjolo Kpatcha🇪🇸 · Debaprasad Maity🇮🇳 · Yann Mambrini🇫🇷

   Post-inflationary reheating phase is usually said to be solely governed by the decay of coherently oscillating inflaton into radiation. In this submission, we explore a new avenue toward reheating through the evaporation of primordial black holes (PBHs). After the inflation, if PBHs form, depending on its initial mass, abundance, and inflaton coupling with the radiation, we found two physically distinct possibilities of reheating the universe. In one possibility, the thermal bath is solely obtained from the decay of PBHs while inflaton plays the role of dominant energy component in the entire process. In the other possibility, we found that PBHs itself dominate the total energy budget of the Universe during the course of evolution, and then its subsequent evaporation leads to radiation dominated universe. Furthermore, we analyze the impact of both monochromatic and extended PBH mass functions and estimate the detailed parameter ranges for which those distinct reheating histories are realized.

   hep-phastro-ph.COgr-qchep-thPRD(2023)·51 citations
4. 04*

   The role of triangle singularity in the decay process $D^0\to {\pi }^{+}{\pi }^{-}{f}_0(980),f_0\to {\pi }^{+}{\pi }^{-}$

   Dazhuang He🇨🇳 · Yiling Xie🇨🇳 · Hao Sun🇨🇳

   We study the process $D^0\to {\pi }^{+}{\pi }^{-}{f}_0(980),f_0\to {\pi }^{+}{\pi }^{-}$ by introducing the triangle mechanism, in which $f_0(980)$ is considered to be dynamically generated from the meson-meson interaction. For the total contribution of this process, the contribution of the triangular loop formed by $K^{\ast }\bar{K}K$ particles could generate a triangular singularity of about 1418 MeV. We calculate the differential decay width of this process and show a narrow peak of about 980 MeV in the ${\pi }^{+}{\pi }^{-}$ invariant mass distribution, which comes from $f_0$ decay. For the $M_{inv}(\pi f_0)$ invariant mass distribution, we obtain a finite peak at 1418 MeV, which is consistent with the triangle singularity.

   hep-phPRD(2023)·3 citations
5. 05*

   Lepton flavor violating decays $l_j\to l_i\gamma \gamma$

   Ming-Yue Liu🇨🇳 · Shu-Min Zhao🇨🇳 · Yi-Tong Wang🇨🇳 · Xi Wang🇨🇳 · Xin-Xin Long🇨🇳 · Tong-Tong Wang🇨🇳 · Hai-Bin Zhang🇨🇳 · Tai-Fu Feng🇨🇳

   In this paper, we study the lepton flavor violating decays of the $l_j\to l_i\gamma \gamma$ (j=2, 3; i=1, 2) processes under the $U(1{)}_X$SSM. The $U(1{)}_X$SSM is the addition of three singlet new Higgs superfields and right-handed neutrinos to the minimal supersymmetric standard model (MSSM). Based on the latest experimental constraints of $l_j\to l_i\gamma \gamma$, we analyze the effects of different sensitive parameters on the results and made reasonable predictions for future experimental development. Numerical analysis shows that many parameters have a greater or lesser effect on lepton flavor violation(LFV), but the main sensitive parameters and sources leading to LFV are the non-diagonal elements involving the initial and final leptons. This work could provide a basis for the discovery of the existence of new physics (NP).

   hep-phNPB(2024)·1 citation
6. 06*

   Hadron-hadron potentials coupled to quark degrees of freedom for exotic hadrons

   Ibuki Terashima🇯🇵 · Tetsuo Hyodo🇯🇵

   We study the properties of the hadron-hadron potentials and quark-antiquark potentials from the viewpoint of the channel coupling. We demonstrate that, for finite quark masses, the coupling to the two-hadron continuum induces the imaginary part of the quark-antiquark potential, in contrast to the string-breaking phenomena in the static limit. It is also shown that the elimination of the different degrees of freedom induces the nonlocality and energy dependence of the effective potentials. For the obtained nonlocal potentials, we apply two methods of the local approximation proposed previously, the formal derivative expansion and the derivative expansion in the HAL QCD method, by carefully examining the energy dependence of the potential. As an application, we construct a coupled-channel model of $c\bar{c}$ and $D^0{\bar{D}}^{\ast 0}$ to describe $X(3872)$, and discuss the property of the effective $D^0{\bar{D}}^{\ast 0}$ potentials. We confirm that the local approximation by the HAL QCD method works better than the formal derivative expansion also for the energy-dependent potential. At the same time, we show that, in the HAL QCD method, the resulting phase shift is sensitive to the choice of the wavefunction to construct the local potential when the system has a shallow bound state such as $X(3872)$.

   hep-phnucl-thPRC(2023)·11 citations
7. 07*

   Precision studies of the post-CT18 LHC Drell-Yan data in the CTEQ-TEA global analysis

   Ibrahim Sitiwaldi🇨🇳 · Keping Xie🇺🇸 · Alim Ablat🇨🇳 · Sayipjamal Dulat🇨🇳 · Tie-Jiun Hou🇨🇳 · C.- P. Yuan🇺🇸

   In this study, we examine closely the impact of the post-CT18 LHC Drell-Yan data on parton distribution functions (PDFs) in the general CTEQ-TEA global analysis framework. We compare the two main theoretical predictions, the MCFM fixed order calculations at next-to-next-to-leading order (NNLO) and the ResBos2 NNLO matched to $q_T$ resummation up to next-to-next-to-next-to-leading logarithmic (N3LL) level. We find that the overall inclusive cross sections agree well but the fiducial distributions can differ at a percent level. We mainly discuss the result of the ResBos2 resummation calculation which yields a smaller Monte-Carlo uncertainty, and a better description to the post-CT18 LHC Drell-Yan data. We find that the majority of post-CT18 LHC Drell-Yan data are consistent with the ATLAS 7 TeV $W,Z$ data, which were included in the CT18A, but not CT18, fit and increases the strange quark distribution at the small $x$ region. The noticeable exception is that the ATLAS and LHCb 8 TeV $W$ data pull $d(\bar{d})$ quark PDFs to the opposite direction with respect to the ATLAS 7 TeV $W,Z$ data. The inclusion of these post-CT18 LHC Drell-Yan data sets in the CTEQ-TEA global analysis is to update the CT18 PDFs following similar trends as CT18Z PDFs. The parton luminosities and a few phenomenological implications with the fiducial $W^{\pm },Z$ and inclusive $H,t\bar{t},t\bar{t}H$ productions at the 14 TeV LHC, as examples, are presented.

   hep-phPRD(2023)·8 citations
8. 08*

   Analysis of $\Xi (1620)$ resonance and $\bar{K}\Lambda$ scattering length with chiral unitary approach

   Takuma Nishibuchi🇯🇵 · Tetsuo Hyodo🇯🇵

   We study the $\Xi (1620)$ resonance near the $\bar{K}\Lambda$ threshold in the light of the recent experimental constraints. The Belle collaboration have found a resonance peak of $\Xi (1620)$ slightly below the ${\bar{K}}^0\Lambda$ threshold in the ${\pi }^{+}{\Xi }^{-}$ invariant mass spectrum, and the ALICE collaboration have determined the $K^{-}\Lambda$ scattering length from the measurement of the momentum correlation functions in the heavy ion collisions. Using the effective range expansion, we classify the nature of the pole of the near-threshold eigenstate in terms of the scattering length, in the presence of the decay channel. It is shown that the quasibound state below the threshold can be described by only the scattering length, while the description of the resonance above the threshold requires the contribution from the effective range. Based on the chiral unitary approach, we construct a theoretical model which generates the pole of $\Xi (1620)$ below the $\bar{K}\Lambda$ threshold with relatively narrow width, as reported by the Belle collaboration. It is quantitatively demonstrated that the spectrum of the $\Xi (1620)$ quasibound state is distorted by the effect of the nearby $\bar{K}\Lambda$ threshold. We then construct another model which reproduces the $K^{-}\Lambda$ scattering length by the ALICE collaboration. In this case, the eigenstate pole does not appear in the physically relevant Riemann sheets, and the spectrum shows a cusp structure at the $\bar{K}\Lambda$ threshold. We finally examine the compatibility of the value of the $\bar{K}\Lambda$ scattering length and the subthreshold pole of $\Xi (1620)$ including the experimental uncertainties.

   hep-phnucl-thPRC(2024)·21 citations
9. 09*

   Bubble-assisted Leptogenesis

   Eung Jin Chun🇰🇷 · Tomasz P. Dutka🇰🇷 · Tae Hyun Jung🇰🇷 · Xander Nagels🇧🇪 · Miguel Vanvlasselaer🇧🇪

   We explore the possibility of embedding thermal leptogenesis within a first-order phase transition (FOPT) such that RHNs remain massless until a FOPT arises. Their sudden and violent mass gain allows the neutrinos to become thermally decoupled, and the lepton asymmetry generated from their decay can be, in principle, free from the strong wash-out processes that conventional leptogenesis scenarios suffer from, albeit at the cost of new washout channels. To quantify the effect of this enhancement, we consider a simple setup of a classically scale-invariant $B-L$ potential, which requires three RHNs with similar mass scales, in the ``strong-washout'' regime of thermal leptogenesis. Here we find that parameter space which requires $M_N\sim 10^{11}\text{ GeV}$ without bubble assistance is now predicted at $M_N\sim 5\times 10^9\text{ GeV}$ suggesting a sizeable reduction from bubble effects. We numerically quantify to what extent such a framework can alleviate strong-washout effects and we find the lower bound on the RHN mass, $M_N\sim 10^7\text{ GeV}$, below which bubble-assisted leptogenesis cannot provide an enhancement. We also study the signature possibly observable at GW terrestrial interferometers and conclude that bubble-assisted leptogenesis models with relatively light masses, $M_N\lesssim 5\times 10^9\text{ GeV}$ may be probable.

   hep-phJHEP(2023)·71 citations
10. 10*

    A novel unbinned model-independent method to measure the CKM angle $\gamma$ in $B^{\pm }\to D{K}^{\pm }$ decays with optimised precision

    Jake Lane🇦🇺 · Evelina Gersabeck🇬🇧 · Jonas Rademacker🇬🇧

    We present a novel unbinned method to combine $B^{\pm }\to D{K}^{\pm }$ and charm threshold data for the amplitude-model unbiased measurement of the CKM angle gamma in cases where the D meson decays to a three-body final state. The new unbinned approach avoids any kind of integration over the D Dalitz plot, to make optimal use the available information. We verify the method with simulated signal data where the D decays to $K_S{\pi }^{+}{\pi }^{-}$. Using realistic sample sizes, we find that the new method reaches the statistical precision on gamma of an unbinned model-dependent fit, i.e. as good as possible and better than the widely used model-independent binned approach, without suffering from biases induced by a mis-modeled D decay amplitude.

    hep-phhep-exJHEP(2023)·6 citations
11. 11*

    Probing Non-Standard Neutrino Interactions with Interference: Insights from Dark Matter and Neutrino Experiments

    Jong-Chul Park🇰🇷 · Gaurav Tomar🇰🇷

    Neutrino-electron scattering experiments play a crucial role in investigating the non-standard interactions of neutrinos. In certain models, these interactions can include interference terms that may affect measurements. Next-generation direct detection experiments, designed primarily for dark-matter searches, are also getting sensitive to probe the neutrino properties. We utilise the data from XENONnT, a direct detection experiment, and Borexino, a low-energy solar neutrino experiment, to investigate the impact of interference on non-standard interactions. Our study considers models with an additional $U(1)$, including $U(1{)}_{B-L}$, $U(1{)}_{L_e-L_{\mu }}$, and $U(1{)}_{L_e-L_{\tau }}$, to investigate the impact of interference on non-standard neutrino interactions. We demonstrate that this interference can lead to a transition between the considered non-standard interaction models in the energy range relevant to both the XENONnT and Borexino experiments. This transition can be used to distinguish among the considered models if any signals are observed at direct detection or neutrino experiments. Our findings underscore the importance of accounting for the interference and incorporating both direct detection and solar neutrino experiments to gain a better understanding of neutrino interactions and properties.

    hep-phhep-exJCAP(2023)·5 citations
12. 12*

    The warm inflation story

    Arjun Berera🇬🇧

    Warm inflation has normalized two ideas in cosmology, that in the early universe the initial primordial density perturbations generally could be of classical rather than quantum origin and that during inflation, particle production from interactions amongst quantum field, and its backreaction effects, can occur concurrent with inflationary expansion. When we first introduced these ideas, both were met with resistance, but today they are widely accepted as possibilities with many models and applications based on them, which is an indication of the widespread influence of warm inflation. Open quantum field theory, which has been utilized in studies of warm inflation, is by now a relevant subject in cosmology, in part due to this early work. In this review I first discuss the basic warm inflation dynamics. I then outline how to compute warm inflation dynamics from first principles quantum field theory (QFT) and in particular how a dissipative term arises. Warm inflation models can have an inflaton mass bigger than the Hubble scale and the inflaton field excursion can remain sub-Planckian, thus overcoming the most prohibitive problems of inflation model building. I discuss the early period of my work in developing warm inflation that helped me arrive at these important features of its dynamics. Inflationary cosmology today is immersed in hypothetical models, which by now are acting as a diversion from reaching any endgame in this field. I discuss better ways to approach model selection and give necessary requirements for a well constrained and predictive inflation model. A few warm inflation models are pointed out that could be developed to this extent. I discuss how at this stage more progress would be made in this subject by taking a broader view on the possible early universe solutions that include not just inflation but the diverse range of options.

    hep-phastro-ph.COUniverse(2023)·64 citations
13. 13*

    Higher-order corrections for $tqZ$ production

    Nikolaos Kidonakis🇺🇸 · Nodoka Yamanaka🇯🇵

    We present theoretical results for the associated production of a single top quark and a $Z$ boson ($tqZ$ production) at LHC energies. We calculate higher-order corrections from soft-gluon emission for this process. We compute the approximate NNLO (aNNLO) cross section at LHC energies, including uncertainties from scale dependence and from parton distributions. We also calculate the top-quark rapidity distribution. The aNNLO corrections are significant and enhance the NLO cross section, and their inclusion provides a more precise theoretical prediction.

    hep-ph1 citation
14. 14*

    Optimizing The Cut And Count Method In Phenomenological Studies

    Baradhwaj Coleppa🇮🇳 · Gokul B. Krishna🇮🇳 · Agnivo Sarkar🇮🇳 · Sujay Shil🇧🇷

    We introduce an optimization technique to discriminate signal and background in any phenomeno- logical study based on the cut and count-based method. The core ideas behind this technique are the introduction of a ranking scheme that can quantitatively assess the relative importance of var- ious observables involved in a new physics process, and a more methodical way of choosing what cuts to impose. The technique is an iterative process that works with the help of the MadAnalysis5 interface. Working in the context of a BSM (Beyond Standard Model) scenario where we carry out a signal search of singly charged Higgs in the context of the Two Higgs Doublet Model (2HDM), we demonstrate how automating the cut and count process in this specific way results in an enhanced discovery potential compared with the more traditional way of imposing cuts.

    hep-phPRD(2026)·0 citations
15. 15*

    Renormalization of the gluon distribution function in the background field formalism

    Tolga Altinoluk🇵🇱 · Guillaume Beuf🇵🇱 · Jamal Jalilian-Marian🇺🇸

    We derive the Leading Order DGLAP evolution of gluon distribution function in the target light cone gauge starting from its standard operator definition. The derivation is performed using the background field formalism also employed in the Color Glass Condensate effective theory of small $x$ QCD. We adopt Mandelstam-Leibbrandt prescription to regulate in an unambiguous way the spurious singularity appearing in the light-cone gauge Feynman propagator. UV divergences are regulated via dimensional regularization. The methods introduced in this paper represent the first steps in the construction of a unified framework for QCD evolution, which could address collinear physics as well as small $x$ physics and gluon saturation.

    hep-phnucl-thPRD(2025)·19 citations
16. 16*

    Valence and sea parton correlations in double parton scattering from data

    Edgar Huayra🇧🇷 · Joao Vitor C. Lovato🇧🇷 · Emmanuel G. de Oliveira🇧🇷

    The effective cross section of double parton scattering in proton collisions has been measured by many experiments with rather different results. Motivated by this fact, we assumed that the parton correlations in the transverse plane are different whether we have valence or sea partons. With this simple approach, we were able to fit the available data and found that sea parton pairs are more correlated in the transverse plane than valence--sea parton pairs.

    hep-phJHEP(2023)·9 citations
17. 17*

    Asymmetric long-lived dark matter and leptogenesis from type-III seesaw framework

    Satyabrata Mahapatra🇰🇷 · Partha Kumar Paul🇮🇳 · Narendra Sahu🇮🇳 · Prashant Shukla🇮🇳

    We propose a simple model in the type-III seesaw framework to explain the neutrino mass, asymmetric dark matter (ADM), and baryon asymmetry of the Universe. We extend the standard model with a vector-like singlet lepton ($\chi$) and a hypercharge zero scalar triplet ($\Delta$) in addition to three hypercharge zero triplet fermions(${\Sigma }_i,i=1,2,3$). A $Z_2$ symmetry is imposed under which $\chi$ and $\Delta$ are odd, while all other particles are even. As a result, the lightest $Z_2$ odd particle $\chi$ behaves as a candidate of DM. In the early Universe, the $CP$-violating out-of-equilibrium decay of heavy triplet fermions to the Standard Model lepton ($L$) and Higgs ($H$) generate a net lepton asymmetry, while that of triplet fermions to $\chi$ and $\Delta$ generate a net asymmetric DM. The lepton asymmetry is converted to the required baryon asymmetry of the Universe via the electroweak sphalerons, while the asymmetry in $\chi$ remains as a DM relic that we observe today. We introduce a singlet scalar $\Phi$, with mass $M_{\varphi }<M_{\chi }$, which not only assists to deplete the symmetric component of $\chi$ through the annihilation process: $\bar{\chi }\chi \to \Phi \Phi$ but also paves a path to detect DM $\chi$ at direct search experiments through $\Phi -H$ mixing. The electro-weak symmetry breaking induces a non-zero vacuum expectation value to $\Delta$, which leads to an unstable asymmetric DM ranging from a few MeV to hundreds of GeV. We then explore the displaced vertex signatures of the charged components of the scalar triplet $\Delta$ at colliders.

    hep-phastro-ph.COPRD(2025)·18 citations
18. 18*

    Cosmology with a supersymmetric local $B-L$ model

    Kwang Sik Jeong🇰🇷 · Wan-il Park🇰🇷

    We propose a minimal gauged $U(1{)}_{B-L}$ extension of the minimal supersymmetric Standard Model (MSSM) which resolves the cosmological moduli problem via thermal inflation, and realizes late-time Affleck-Dine leptogensis so as to generate the right amount of baryon asymmetry at the end of thermal inflation. The present relic density of dark matter can be explained by sneutrinos, MSSM neutralinos, axinos, or axions. Cosmic strings from $U(1{)}_{B-L}$ breaking are very thick, and so the expected stochastic gravitational wave background from cosmic string loops has a spectrum different from the one in the conventional Abelian-Higgs model, as would be distinguishable at least at LISA and DECIGO. The characteristic spectrum is due to a flat potential, and may be regarded as a hint of supersymmetry. Combined with the resolution of moduli problem, the expected signal of gravitational waves constrains the $U(1{)}_{B-L}$ breaking scale to be $\mathcal{O}(10^{12-13})\mathrm{GeV}$. Interestingly, our model provides a natural possibility for explaining the observed ultra-high-energy cosmic rays thanks to the fact that the core width of strings in our scenario is very large, allowing a large enhancement of particle emissions from the cusps of string loops. Condensation of $L{H}_u$ flat-direction inside of string cores arises inevitably and can also be the main source of the ultra-high-energy cosmic rays accompanied by ultra-high-energy lightest supersymmetric particles.

    hep-phJCAP(2023)·3 citations
19. 19*

    Searching for Scalar Ultralight Dark Matter with Optical Fibers

    J. Manley🇺🇸 · R. Stump🇺🇸 · R. Petery🇺🇸 · S. Singh🇺🇸

    We consider optical fibers as detectors for scalar ultralight dark matter (UDM) and propose using a fiber-based interferometer to search for scalar UDM with particle mass in the range $10^{-17}-10^{-13}$ eV/$c^2$ $\left(10^{-3}-10\text{ Hz}\right)$. Composed of a solid core and a hollow core fiber, the proposed detector would be sensitive to relative oscillations in the fibers' refractive indices due to scalar UDM-induced modulations in the fine-structure constant $\alpha$. We predict that, implementing detector arrays or cryogenic cooling, the proposed optical fiber-based scalar UDM search has the potential to reach new regions of the parameter space. Such a search would be particularly well-suited to probe for a Solar halo of dark matter with a sensitivity exceeding that of previous DM searches over the particle mass range $7\times 10^{-17}-2\times 10^{-14}$ eV/$c^2$.

    hep-phastro-ph.IMphysics.ins-detphysics.optics+1PRD(2023)·4 citations
20. 20*

    Slow Complexification

    Brett McInnes🇸🇬

    The fact that AdS black hole interior geometries are time-dependent presents two challenges: first, to holographic duality (the boundary matter tends to equilibrate, often very quickly), and, second, to the idea that wormholes can be traversable (the wormhole geometry is dynamic, and the wormhole is apt to collapse too quickly for traversal to be possible). As is well known, the first puzzle can be addressed by considering the quantum circuit complexity of the strongly coupled boundary matter, which can continue to grow long after equilibrium is established. We show that data from a phenomenological model of the Quark-Gluon Plasma indicate the existence of an upper bound on the rate of increase of the (specific) complexity, in agreement with a simple holographic model. We then point out that, in this model, this upper bound becomes stricter if angular momentum is added to the bulk black hole while fixing the temperature (at any value, so the black hole is \emph{not} near-extremal). We show that the dual phenomenon, a dramatic slowing of the black hole interior dynamics at high specific angular momentum, also occurs. We conjecture that sufficiently slow complexification of the field theories dual to rotating black holes is associated with traversability of the bulk wormhole, when quantum effects are taken into account.

    ↳ hep-thgr-qchep-phNPB(2024)·2 citations
21. 21*

    Bottomonium production in pp and heavy-ion collisions

    Taesoo Song🇩🇪 · Joerg Aichelin🇫🇷 · Jiaxing Zhao🇫🇷 · Pol Bernard Gossiaux🇫🇷 · Elena Bratkovskaya🇩🇪

    We study bottomonium $b\bar{b}$ production in pp collisions as well as in heavy-ion collisions, using a quantal density matrix approach. The initial bottom (anti)quarks are provided by the PYTHIA event generator. We solve the Schrödinger equation for the $b\bar{b}$ pair, identifying the potential with the free energy, calculated with lattice QCD, to obtain the temperature dependent $b\bar{b}$ density matrix as well as the dissociation temperature. The formation of bottomonium is given by projection of the bottomonium density matrix onto the density matrix of the system. With this approach we describe the rapidity and transverse momentum distribution of the ${\rm Y}$(nS) in pp collisions at $\sqrt{s_{\mathrm{NN}}}=$ 5.02 TeV extending a similar calculation for the charmonium states \cite{Song:2017phm}. We employ the Remler formalism to study the $b\bar{b}$ production in heavy ion collisions in which the heavy quarks scatter elastically with partons from the quark gluon plasma (QGP). The elastic scattering of heavy (anti)quark in QGP is realized by the dynamical quasi-particle model (DQPM) and the expanding QGP is modeled by PHSD. We find that a reduction to 10 \% of the scattering cross section for a (anti)bottom quark with a QGP parton reproduces the experimental data. This suggests that due to color neutrality the scattering cross section of the small $b\bar{b}$ system with a parton is considerably smaller than twice the bottom-parton scattering cross section.

    ↳ nucl-thhep-phnucl-exPRC(2023)·29 citations
22. 22*

    Microscopic Encoding of Macroscopic Universality: Scaling Properties of Dirac Eigenspectra near QCD Chiral Phase Transition

    Heng-Tong Ding🇨🇳 · Wei-Ping Huang🇨🇳 · Swagato Mukherjee🇺🇸 · Peter Petreczky🇺🇸

    Macroscopic properties of the strong interaction near its chiral phase transition exhibit scaling behaviors, which are the same as those observed close to the magnetic transition in a 3-dimensional classical spin system with $O(4)$ symmetry. We show that the universal scaling properties of the chiral phase transition in Quantum Chromodynamics (QCD) at the macroscale are, in fact, encoded within the microscopic energy levels of its fundamental constituents, the quarks. We establish a connection between the cumulants of the chiral order parameter, i.e., the chiral condensate, and the correlations among the energy levels of quarks, i.e., the eigenspectra of the massless QCD Dirac operator. This relation elucidates how the fluctuations of the chiral condensate arise from the correlations within the infrared part of the energy spectra of quarks, and naturally leads to a generalization of the Banks-Casher relation for the cumulants of the chiral condensate. Then, through (2+1)-flavor lattice QCD calculations with varying light quark masses near the QCD chiral transition, we demonstrate that the correlations among the infrared part of the Dirac eigenvalue spectra exhibit same universal scaling behaviors as expected of the cumulants of the chiral condensate. We find that these universal scaling behaviors extend up to the physical values of the up and down quark masses. Our study reveals how the hidden scaling features at the microscale give rise to the macroscopic universal properties of QCD.

    ↳ hep-lathep-phhep-thnucl-thPRL(2023)·16 citations
23. 23*

    Blockwise inversion and algorithms for inverting large partitioned matrices

    R. Thiru Senthil🇮🇳

    Block matrix structure is commonly arising is various physics and engineering applications. There are various advantages in preserving the blocks structure while computing the inversion of such partitioned matrices. In this context, using the blockwise matrix inversion technique, inversions of large matrices with different ways of memory handling are presented, in this article. An algorithm for performing inversion of a matrix which is partitioned into a large number of blocks is presented, in which inversions and multiplications involving the blocks are carried out with parallel processing. Optimized memory handling and efficient methods for intermediate multiplications among the partitioned blocks are implemented in this algorithm. The developed programs for the procedures discussed in this article are provided in C language and the parallel processing methodology is implemented using OpenMP application programming interface. The performance and the advantages of the developed algorithms are highlighted.

    ↳ math.NAcs.NAhep-exhep-ph+20 citations
24. 24*

    Moments of proton GPDs from the OPE of nonlocal quark bilinears up to NNLO

    Shohini Bhattacharya🇺🇸 · Krzysztof Cichy🇵🇱 · Martha Constantinou🇺🇸 · Xiang Gao🇺🇸 · Andreas Metz🇺🇸 · Joshua Miller🇺🇸 · Swagato Mukherjee🇺🇸 · Peter Petreczky🇺🇸 · Fernanda Steffens🇩🇪 · Yong Zhao🇺🇸

    For the first time, we present a lattice QCD determination of Mellin moments of unpolarized generalized parton distributions (GPDs) of the proton from an analysis of the quasi-GPD matrix elements within the short-distance factorization framework. We perform our calculation on an $N_f$=2+1+1 twisted mass fermions ensemble with a clover improvement at lattice spacing $a=0.093$ fm and a pion mass of $m_{\pi }=260$ MeV. Focusing on the zero-skewness case, the iso-vector and iso-scalar quasi-GPDs are calculated from the ${\gamma }_0$ definition, as well as a recently proposed Lorentz-invariant definition. We utilize data on both symmetric and asymmetric kinematic frames, which allows us to obtain the Mellin moments for several values of the momentum transfer, $-t$, in the range 0.17 to $2.77{\mathrm{GeV}}^2$. We use the ratio scheme for GPDs, i.e. renormalization group invariant ratios with leading-twist factorization formula and perturbatively calculated matching coefficients up to the next-next-to-leading order (NNLO) to extract Mellin moments of GPDs, which are consistent with renormalization-group improved results. We compare our determination from quasi-GPDs with the results extracted using standard calculations of Mellin moments of local operators, specifically those related to the electromagnetic and gravitational form factors. We estimated the moments of GPDs up to the fifth ones for the first time. By extrapolating the Mellin moments to $-t=0$, we obtained the quark charges, momentum fraction, as well as the angular momentum contributions to the proton spin. The impact parameter space interpretation of the GPD moments is discussed, which provides insights into the spatial distribution of unpolarized quarks and their correlations in the transverse plane of an unpolarized or transversely polarized proton.

    ↳ hep-lathep-phnucl-thPRD(2023)·55 citations
25. 25*

    Fast Neutrino Flavor Conversions can Help and Hinder Neutrino-Driven Explosions

    Jakob Ehring (1,2,3)🇩🇪 · Sajad Abbar (1)🇩🇪 · Hans-Thomas Janka (2)🇩🇪 · Georg Raffelt (1)🇩🇪 · Irene Tamborra (4) ((1) MPI Physik, (2) MPI Astrophysik, (3) TUM Garching, (4) Niels Bohr Institute)🇩🇰

    We present the first simulations of core-collapse supernovae in axial symmetry with feedback from fast neutrino flavor conversion (FFC). Our schematic treatment of FFCs assumes instantaneous flavor equilibration under the constraint of lepton-number conservation individually for each flavor. Systematically varying the spatial domain where FFCs are assumed to occur, we find that they facilitate SN explosions in low-mass (9-12 solar masses) progenitors that otherwise explode with longer time delays, whereas FFCs weaken the tendency to explode of higher-mass (around 20 solar masses) progenitors.

    ↳ astro-ph.HEastro-ph.SRgr-qchep-ph+1PRL(2023)·110 citations
26. 26*

    Quantum Gravity Background in Next-Generation Gravitational Wave Detectors

    Mathew W. Bub🇺🇸 · Yanbei Chen🇺🇸 · Yufeng Du🇺🇸 · Dongjun Li🇺🇸 · Yiwen Zhang🇺🇸 · Kathryn M. Zurek🇺🇸

    We study the effects of geontropic vacuum fluctuations in quantum gravity on next-generation terrestrial gravitational wave detectors. If the VZ effect proposed in Ref. [1], as modeled in Refs. [2, 3], appears in the upcoming GQuEST experiment, we show that it will be a large background for astrophysical gravitational wave searches in observatories like Cosmic Explorer and the Einstein Telescope.

    ↳ gr-qchep-phhep-thPRD(2023)·19 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.