Tue·Sep 6, 2022Tuesday·September 6, 2022

1. 01*

   Gravitational form factors of the delta resonance in chiral EFT

   H. Alharazin🇩🇪 · E. Epelbaum🇩🇪 · J. Gegelia🇩🇪 · U.-G. Meißner🇩🇪 · B.-D. Sun🇨🇳

   The leading one-loop corrections to the gravitational form factors of the delta resonance are calculated in the framework of chiral effective field theory. Various contributions to the energy-momentum tensor and the renormalization of the low-energy constants are worked out. Using the small scale expansion, expressions for static quantities are obtained and the real and imaginary parts of the gravitational form factors are calculated numerically.

   hep-phhep-exhep-latEPJC(2022)·27 citations
2. 02*

   Resumming Quark's Longitudinal Momentum Logarithms in LaMET Expansion of Lattice PDFs

   Yushan Su🇺🇸 · Jack Holligan🇺🇸 · Xiangdong Ji🇺🇸 · Fei Yao🇨🇳 · Jian-Hui Zhang🇨🇳 · Rui Zhang🇺🇸

   In the large-momentum expansion for parton distribution functions (PDFs), the natural physics scale is the longitudinal momentum ($p_z$) of the quarks (or gluons) in a large-momentum hadron. We show how to expose this scale dependence through resumming logarithms of the type ${\ln }^n{p}_z/\mu$ in the matching coefficient, where $\mu$ is a fixed renormalization scale. The result enhances the accuracy of the expansion at moderate $p_z>1$ GeV, and at the same time, clearly shows that the partons cannot be approximated from quarks with $p_z\sim {\Lambda }_{\mathrm{QCD}}$ which are not predominantly collinear with the parent hadron momentum, consistent with power counting of the large-momentum effective theory. The same physics mechanism constrains the coordinate space expansion at large distances $z$, the conjugate of $p_z$, as illustrated in the example of fitting the moments of the PDFs.

   hep-phhep-latnucl-thNPB(2023)·62 citations
3. 03*

   Soft breaking of the $\mu \leftrightarrow \tau$ symmetry by ${\mathbf{S}}_4\otimes {\mathbf{Z}}_2$

   J. D. García-Aguilar🇲🇽 · Asahel Enrique Pozas Ramírez🇲🇽 · Marlon Michael Suárez Castañeda🇲🇽 · Juan Carlos Gómez-Izquierdo🇲🇽

   The $\mu \leftrightarrow \tau$ symmetry has been ruled out by its predictions on the reactor and atmospheric angles, nevertheless, a breaking of this symmetry might provide correct values. For that reason, we build a non-renormalizable lepton model where the mixings arise from the spontaneous breaking of the ${\mathbf{S}}_4\otimes {\mathbf{Z}}_2$ discrete group, subsequently the $\mu \leftrightarrow \tau$ symmetry is broken in the effective neutrino mass matrix, that comes from the type II see-saw mechanism. As main result, the reactor and atmospheric angles are corrected and their values are in good agreement with the experimental data for the inverted hierarchy. Furthermore, we point out a link between the atmospheric angle and reactor one. In the quark sector, under certain assumptions, the generalized Fritzsch textures shape to the quark mass matrices so that the CKM matrix values are guaranteed.

   hep-phRev.Mex.Fis.(2023)·6 citations
4. 04*

   The high-energy limit of perturbative QCD: Theory and phenomenology

   Francesco Giovanni Celiberto🇮🇹 · Michael Fucilla🇮🇹 · Alessandro Papa🇮🇹

   After a brief introduction of formal and phenomenological progresses in the study of the high-energy limit of perturbative QCD, we present arguments supporting the statement that the inclusive emission of Higgs bosons or heavy-flavored hadrons acts as fair stabilizer of high-energy resummed differential distributions. We come out with the message that the hybrid high-energy and collinear factorization, built in term of the next-to-leading logarithmic resummation \emphà la} BFKL and supplemented by collinear parton distributions and fragmentation functions, is a valid and powerful tool to gauge the feasibility of precision analyses of QCD in its high-energy limit.

   hep-phEPJ Web Conf. 270 (2022) 00001·13 citations
5. 05*

   511 keV galactic line from first-order phase transitions and primordial black holes

   Po-Yan Tseng🇹🇼 · Yu-Min Yeh🇹🇼

   Hawking evaporation of primordial black hole (PBH), with mass $3\times 10^{-17}\lesssim M_{\mathrm{PBH}}/M_{\odot }\lesssim 7\times 10^{-17}$ and fractional abundance $0.01\lesssim f_{\mathrm{PBH}}\lesssim 0.5$, well reproduces 511 keV gamma-ray excess from galaxy center. In this work, we investigated the production mechanism of PBHs base on the first-order phase transition induced by quartic effective thermal potential of a scalar field in dark sector. We found the phase transition with vacuum energy, $\mathcal{O}(1)\lesssim B^{1/4}/\mathrm{MeV}\lesssim \mathcal{O}(100)$, produces the desired PBH mass and abundance fraction. Correlated signatures of gravitational wave and extragalactic gamma-ray from phase transition and black hole evaporation, respectively, are within $\mu$Ares and AMEGO/e-ASTROGAM projected sensitivities.

   hep-phJCAP(2023)·12 citations
6. 06*

   Intrinsic asymmetries in semi-inclusive deeply inelastic scattering at the Electron-Ion Collider

   Weihua Yang🇨🇳 · Xinghua Yang🇨🇳

   We calculate the neutral current jet production semi-inclusive deeply inelastic scattering process in this paper. Neutral current implies that interactions can be mediated by the photon, $Z^0$-boson and their interference. The initial electron is assumed to be polarized and then scattered off by a target particle with spin-1/2. Calculations are carried out up to twist-3 level in the quantum chromodynamics parton model by applying the collinear expansion formalism where multiple gluon scattering is taken into account and gauge links are obtained automatically. After obtaining the differential cross section, we introduce the definition of the intrinsic asymmetry. This quantity reveals the asymmetry in the distribution of the quark intrinsic transverse momentum. We find that these asymmetries can be expressed in terms of the transverse momentum dependent parton distribution functions and the electroweak couplings. As a result, our calculations provide a set of new quantities for analyzing the parton distribution functions and the electroweak couplings. It is helpful to understand the hadronic weak interactions and strong interactions in the deeply inelastic scattering process simultaneously.

   hep-phPRD(2022)·12 citations
7. 07*

   Searching for tetraquark through weak decays of b-baryons

   Fei Huang🇨🇳 · Ye Xing🇨🇳 · Ji Xu🇨🇳

   After the experimental observation of charged and neutral $Z_c(3900)$, it is of prime importance to pursue searches for additional production modes of these exotic states. In this work, we investigate the possibility to study the $Z_c(3900)$ through weak decays of b-baryons at the LHCb. Decay amplitudes for various processes have been parametrized in terms of the SU(3) irreducible nonperturbative amplitudes. A number of relations for the partial decay widths are deduced from these results. The decay widths of ${\Lambda }_b^0\to {\Lambda }^0{Z}_c^0(3900)$, ${\Xi }_b^{-}\to {\Sigma }^{-}{Z}_c^0(3900)$ and ${\Xi }_b^0\to {\Lambda }^0{Z}_c^0(3900)$ have also been calculated from which some relevant partial decay widths of b-baryons could be estimated. The results presented in this paper can be tested experimentally at hadron colliders in the future.

   hep-phEPJC(2022)·10 citations
8. 08*

   Scattering of low energy neutrinos and antineutrinos by neon and argon

   Ian B Whittingham🇦🇺

   The theory of scattering of low energy neutrinos and antineutrinos by atomic electrons has recently been developed (I. B. Whittingham, Phys. Rev. D 105, 013008 (2022)) using the Bound Interaction Picture in configuration space to fully implement the relationship between the neutrino helicities and the orbital and spin angular momenta of the atomic electrons. The energy spectra of ionization electrons produced by scattering of neutrinos and antineutrinos with energies of 5, 10, 20, and 30 keV by hydrogen, helium and neon were calculated using Dirac screened Coulombic eigenfunctions. This paper reports further applications of this theory, to a new calculation of the energy spectra for neon, as the original calculation used some screening constants which underestimated the effects of screening in the inner subshells, and to scattering by argon. The results are presented as ratios to the corresponding quantities for scattering by $Z$ free electrons. The new spectra ratios for neon are larger than the original ratios by approx 0.03 to approx 0.14, with the greatest increases occurring for 10 keV neutrinos and antineutrinos. Integrated spectra ratios range from 0.16 to 0.59 for neon, and from 0.15 to 0.48 for argon, as the neutrino energy increases from 5 to 30 keV.

   hep-phPRD(2022)·1 citation
9. 09*

   Possible origin of HADES data on proton number fluctuations in Au+Au collisions

   O. Savchuk🇺🇦 · R. V. Poberezhnyuk🇺🇦 · M.I. Gorenstein🇺🇦

   Recent data of the HADES Collaboration in Au+Au central collisions at $\sqrt{s_{\mathrm{NN}}}=2.4$ GeV indicate large proton number fluctuations inside one unit of rapidity around midrapidity. This can be a signature of critical phenomena due to the strong attractive interactions between baryons. We study an alternative hypothesis that these large fluctuations are caused by the event-by-event fluctuations of the number of bare protons, and no interactions between these protons are assumed. The proton number fluctuations in five symmetric rapidity intervals $\Delta y$ inside the region $\Delta Y=1$ are calculated using the binomial acceptance procedure. This procedure assumes the independent (uncorrelated) emission of protons, and it appears to be in agreement with the HADES data. To check this simple picture we suggest to calculate the correlation between proton multiplicities in non-overlapping rapidity intervals $\Delta y_1$ and $\Delta y_2$ placed inside $\Delta Y=1$.

   hep-phnucl-thPLB(2022)·6 citations
10. 10*

    Determine the quantum numbers of $X(6900)$ from photon-photon fusion in ultra-peripheral heavy ion collisions

    Peng-Yu Niu🇨🇳 · Enke Wang🇨🇳 · Qian Wang · Shuai Yang🇨🇳

    We study the production of the $X(6900)$ through the $J/\psi J/\psi$ decay channel in the ultra-peripheral heavy ion collisions at the LHC energy region. The potential quantum numbers of $X(6900)$ would be $0^{\pm +}$ and $2^{\pm +}$. We find that the transverse momentum and the polar angle distributions of $X(6900)$ can be used to distinguish these four potential quantum numbers. These typical distributions stem from the linearly polarized photon from the fast-moving nuclei and can be measured with the LHC experiments in further.

    hep-phChin.Phys.Lett.(2025)·18 citations
11. 11*

    Hidden SU(2)_D vector dark matter with a scalar septuplet

    Zhao Zhang🇨🇳 · Chengfeng Cai🇨🇳 · Hong-Hao Zhang🇨🇳

    We propose a vector dark matter model from a hidden SU(2)_D gauge symmetry at TeV scale. A scalar septuplet is introduced to break the SU(2)_D symmetry spontaneously. The septuplet also play the role of a portal between the standard model and the dark sector. We find that there are two different vacuum configurations corresponding to the sign of the quartic coupling ${\lambda }_3$, which yields different mass spectrum for the gauge bosons. For a ${\lambda }_3<0$, the masses of gauge bosons are splitting, while for a ${\lambda }_3\ge 0$, the masses are degenerate. We also study the RG evolutions of the couplings, and find that the perturbativity and vacuum stability can set a stringent bound on the parameter space. For the phenomenological aspect, we consider the experimental constraints including dark matter direct detection, indirect detection, relic density, and Higgs couplings measurements. We find that there are parameter space survive from all the constraints, and they can be tested in future dark matter direct and indirect detection experiments.

    hep-phPRD(2022)·3 citations
12. 12*

    Elementary particle non-perturbative mass generation. A step towards a beyond-the-Standard-Model model

    Giancarlo Rossi🇮🇹

    We show that a recently discovered non-perturbative field-theoretical mechanism giving mass to elementary fermions, is also capable of generating a mass for the electro-weak bosons and can thus be used as a viable alternative to the Higgs scenario. A detailed analysis of this remarkable feature shows that the non-perturbatively generated fermion and $W$ masses have the parametric form $m_f\sim C_f(\alpha ){\Lambda }_{RGI}$ and $M_W\sim g_w{c}_w(\alpha ){\Lambda }_{RGI}$, respectively, where the coefficients $C_f(\alpha )$ and $c_w(\alpha )$ are functions of the gauge couplings, $g_w$ is the weak coupling and ${\Lambda }_{\mathrm{RGI}}$ is the RGI scale of the theory. In view of these expressions, we see that to match the experimental values of the top quark and $W$ masses, we are led to conjecture the existence of a yet unobserved sector of massive fermions (that we denote Tera-fermions) subjected, besides ordinary Standard Model interactions, to some kind of super-strong gauge interactions (Tera-interactions), so that the full theory (SM plus Tera-particles) will have an RGI scale ${\Lambda }_{\mathrm{RGI}}\equiv {\Lambda }_T$ in the TeV region. This approach offers a solution of the mass naturalness problem (there is no fundamental Higgs), an understanding of the fermion mass hierarchy and a physical interpretation of the electro-weak scale as a fraction of ${\Lambda }_T$.

    hep-phhep-thNucl.Part.Phys.Proc.(2023)·5 citations
13. 13*

    Investigations of the semileptonic decays of $D$ and $D_s$ into a pseudoscalar meson using the Isgur-Wise Functions

    S. Rahmani🇨🇳 · C. W. Xiao🇨🇳

    The branching ratios of the semileptonic decay widths of the charm mesons are analyzed, using three different models for the Isgur-Wise functions, such as $D^0\to K^{-}{l}^{+}\upsilon$, $D^0\to {\pi }^{-}{l}^{+}\nu$, $D_s\to K^0{l}^{+}\nu$ and $D_s\to \eta l^{+}\nu$, where the form factors of these decays are discussed. The mass spectra of the charm mesons are obtained. We use a potential quark model and consider the non-relativistic Hamiltonian of the charm meson as a bound state of the quark-antiquark system. We take into account the harmonic-type confinement and also Hellmann potential, which is a superposition of the Coulomb and the Yukawa potential. Using the variational approach along with the harmonic oscillator wave functions, we evaluate the mass spectra of the charm mesons, the form factors and the semileptonic decay widths of $D_{(s)}$. We present our results for masses of $D,D_s$ and $\eta$, the Isgur-Wise functions, the form factors of the semileptonic decays, and the branching fractions of the semileptonic decays of $D$ and $D_s$. Our results are motivating.

    hep-phEur.Phys.J.Plus(2023)·3 citations
14. 14*

    The Nucleon Energy Correlators

    Xiaohui Liu🇨🇳 · Hua Xing Zhu🇨🇳

    We introduce the concept of the nucleon energy correlators, a set of novel objects that encode the microscopic details of a nucleon, such as the parton angular distribution in a nucleon, the collinear splitting to all orders, as well as the internal transverse dynamics of the nucleon. The nucleon energy correlators complement the conventional nucleon/nucleus tomography, but without introducing the non-perturbative fragmentation functions or the jet clustering algorithms. We demonstrate how the nucleon energy correlators can be measured in the lepton-nucleon deep inelastic scattering. The predicted distributions display a fascinating phase transition between the perturbative and non-perturbative regime. In the perturbative phase, a polar angle version of the Bjorken scaling behavior is predicted. We discuss its possible applications and expect it aggrandize the physics content at the electron ion colliders with a far-forward detector.

    hep-phhep-exnucl-exPRL(2023)·85 citations
15. 15*

    Subtracting Compact Binary Foregrounds to Search for Subdominant Gravitational-Wave Backgrounds in Next-Generation Ground-Based Observatories

    Bei Zhou🇺🇸 · Luca Reali🇺🇸 · Emanuele Berti🇺🇸 · Mesut Çalışkan🇺🇸 · Cyril Creque-Sarbinowski🇺🇸 · Marc Kamionkowski🇺🇸 · B. S. Sathyaprakash🇺🇸

    Stochastic gravitational-wave backgrounds (SGWBs) derive from the superposition of numerous individually unresolved gravitational-wave (GW) signals. Detecting SGWBs provides us with invaluable information about astrophysics, cosmology, and fundamental physics. In this paper, we study SGWBs from binary black-hole (BBH) and binary neutron-star (BNS) coalescences in a network of next-generation ground-based GW observatories (Cosmic Explorer and Einstein Telescope) and determine how well they can be measured; this then limits how well we can observe other subdominant astrophysical and cosmological SGWBs. We simulate all-Universe populations of BBHs and BNSs and calculate the corresponding SGWBs, which consist of a superposition of (i) undetected signals, and (ii) the residual background from imperfect removal of resolved sources. The sum of the two components sets the sensitivity for observing other SGWBs. Our results show that, even with next-generation observatories, the residual background is large and limits the sensitivity to other SGWBs. The main contributions to the residual background arise from uncertainties in inferring the coalescence phase and luminosity distance of the detected signals. Alternative approaches to signal subtraction would need to be explored to minimize the BBH and BNS foreground in order to observe SGWBs from other subdominant astrophysical and cosmological sources.

    ↳ gr-qcastro-ph.HEhep-phPRD(2023)·65 citations
16. 16*

    Muon Collider Forum Report

    K.M. Black · S. Jindariani · D. Li · F. Maltoni · P. Meade · D. Stratakis · D. Acosta · R. Agarwal · K. Agashe · C. Aime · D. Ally · A. Apresyan and 173 other authors

    A multi-TeV muon collider offers a spectacular opportunity in the direct exploration of the energy frontier. Offering a combination of unprecedented energy collisions in a comparatively clean leptonic environment, a high energy muon collider has the unique potential to provide both precision measurements and the highest energy reach in one machine that cannot be paralleled by any currently available technology. The topic generated a lot of excitement in Snowmass meetings and continues to attract a large number of supporters, including many from the early career community. In light of this very strong interest within the US particle physics community, Snowmass Energy, Theory and Accelerator Frontiers created a cross-frontier Muon Collider Forum in November of 2020. The Forum has been meeting on a monthly basis and organized several topical workshops dedicated to physics, accelerator technology, and detector R&D. Findings of the Forum are summarized in this report.

    ↳ hep-exhep-phJINST(2024)·173 citations
17. 17*

    Tree-level entanglement in Quantum Electrodynamics

    Samuel Fedida🇬🇧 · Alessio Serafini🇬🇧

    We report on a systematic study on the entanglement between helicity degrees of freedom generated at tree-level in quantum electrodynamics two-particle scattering processes. We determine the necessary and sufficient dynamical conditions for outgoing particles to be entangled with one another, and expose the hitherto unknown generation of maximal or nearly maximal entanglement through Bhabha and Compton scattering. Our work is an early step in revisiting quantum field theory and high-energy physics in the light of quantum information theory.

    ↳ quant-phhep-phPRD(2023)·62 citations
18. 18*

    Has J-PARC E07 observed a ${\Xi }_{1s}^{-}$ nuclear state?

    E. Friedman🇮🇱 · A. Gal🇮🇱

    The Strangeness $\mathcal{S}=-2$ J-PARC E07 emulsion experiment published recently two new ${\Xi }^{-}$--${}^{14}$N capture events, IRRAWADDY and IBUKI, identified by observing weak-decay sequences of pairs of single-$\Lambda$ hypernuclei and interpreted as ${\Xi }_{1s}^{-}$ and ${\Xi }_{1p}^{-}$ nuclear bound states, respectively, with binding energies $B_{{\Xi }^{-}}^{1s}$=6.27$\pm$0.27 MeV and $B_{{\Xi }^{-}}^{1p}$=1.27$\pm$0.21 MeV. ${\Xi }^{-}$ capture events in emulsion play a major role in determining the $\Xi$-nuclear and the $\Lambda \Lambda$ potential strengths. Here we question the assignment of a ${\Xi }_{1s}^{-}$ nuclear bound state to IRRAWADDY and offer an alternative assignment as a near-threshold ${\Xi }_{1p}^0$--${}^{14}$C nuclear bound state, slightly admixed with a ${\Xi }_{1p}^{-}$--${}^{14}$N nuclear bound state component corresponding to IBUKI. We also question using IBUKI's $B_{{\Xi }^{-}}^{1p}$ value as is to determine the $\Xi$-nuclear potential depth. Altogether, ${\Xi }^{-}$ capture events in ${}^{12}$C and ${}^{16}$O should prove less ambiguous than in ${}^{14}$N.

    ↳ nucl-thhep-phnucl-exPLB(2023)·16 citations
19. 19*

    Mass splitting and spin alignment for $\varphi$ mesons in a magnetic field in NJL model

    Xin-Li Sheng🇨🇳 · Shu-Yun Yang🇨🇳 · Yao-Lin Zou🇨🇳 · Defu Hou🇨🇳

    Based on the Nambu-Jona-Lasinio (NJL) model, we develop a framework for calculating the spin alignment of vector mesons and applied it to study $\varphi$ mesons in a magnetic field. We calculate mass spectra for $\varphi$ mesons and observe mass splitting between the longitudinally polarized state and transversely polarized states. The $\varphi$ meson in a thermal equilibrium system is preferred to occupy the state with spin $\lambda =0$ than those with spin $\lambda =\pm 1$, because the former state has a smaller energy. As a consequence, we conclude that the spin alignment will be larger than 1/3 if one measures along the direction of the magnetic field, which is qualitatively consistent with the recent STAR data. Around the critical temperature $T_C=150$ MeV, the positive deviation from 1/3 is proportional to the square of the magnetic field strength, which agrees with the result from the non-relativistic coalescence model. Including the anomalous magnetic moments for quarks will modify the dynamical masses of quarks and thus affect the mass spectra and spin alignment of $\varphi$ mesons. The discussion of spin alignment in the NJL model may help us better understand the formation of hadron's spin structure during the chiral phase transition.

    ↳ nucl-thhep-phEPJC(2024)·29 citations
20. 20*

    Benchmarking the cosmological master equations

    Thomas Colas🇫🇷 · Julien Grain🇫🇷 · Vincent Vennin🇫🇷

    Master equations are commonly employed in cosmology to model the effect of additional degrees of freedom, treated as an "environment", onto a given "system". However, they rely on assumptions that are not necessarily satisfied in cosmology, where the environment may be out of equilibrium and the background is dynamical. In this work, we apply the master-equation program to a model that is exactly solvable, and which consists of two linearly coupled scalar fields evolving on a cosmological background. The light field plays the role of the system and the heavy field is the environment. By comparing the exact solution to the output of the master equation, we can critically assess its performance. We find that the master equation exhibits a set of "spurious" terms that explicitly depend on the initial conditions, and which arise as a consequence of working on a dynamical background. Although they cancel out in the perturbative limit of the theory (i.e. at leading orders in the interaction strength), they spoil resummation. However, when those terms are removed, the master equation performs impressively well to reproduce the power spectra and the amount of the decoherence of the light field, even in the strongly decohered regime. We conclude that master equations are able to perform late-time resummation, even though the system is far from the Markovian limit, provided spurious contributions are suppressed.

    ↳ hep-thastro-ph.COgr-qchep-phEPJC(2022)·69 citations
21. 21*

    Recovering the conformal limit of color superconducting quark matter within a confining density functional approach

    Oleksii Ivanytskyi🇵🇱 · David Blaschke🇵🇱

    We generalize a recently proposed confining relativistic density-functional approach to the case of density dependent vector and diquark couplings. The particular behavior of these couplings is motivated by the non-perturbative gluon exchange in dense quark matter and provides the conformal limit at asymptotically high densities. We demonstrate that this feature of the quark matter EoS is consistent with a significant stiffness in the density range typical for the interiors of neutron stars. In order to model these astrophysical objects we construct a family of hybrid quark-hadron EoSs of cold stellar matter. We also confront our approach with the observational constraints on the mass-radius relation of neutron stars and their tidal deformabilities and argue in favor of a quark matter onset at masses below $1.0{\mathrm{M}}_{\odot }$

    ↳ nucl-thastro-ph.HEhep-phParticles(2022)·35 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.