Fri·Jun 9, 2023Friday·June 9, 2023

1. 01*

   Signals of strong parity violation in deep inelastic scattering

   Alessandro Bacchetta🇮🇹 · Matteo Cerutti🇮🇹 · Ludovico Manna🇮🇹 · Marco Radici🇮🇹 · Xiaochao Zheng🇺🇸

   We include strong parity-violating contributions to inclusive deep inelastic scattering (DIS) of longitudinally polarized leptons off an unpolarized target. At variance with standard results, we obtain nonvanishing parity-violating structure functions in the case of pure photon exchange. The addition of these strong parity-violating contributions improves the description of existing experimental data on DIS parity-violating asymmetries. We find the size of these contributions small but exhibiting a deviation from zero of about 1.5 $\sigma$. The associated $p$-value is 0.063, indicating that the probability of making an error by rejecting the hypothesis of no parity-violating contributions is 6.3\%, which is small but not negligible. Further improvement on the limit of the strong parity-violation can be expected from the future SoLID program at Jefferson Lab.

   hep-phhep-exnucl-exnucl-thPLB(2024)·9 citations
2. 02*

   Forward $\gamma$+jet production in proton-proton and proton-lead collisions at LHC within the FoCal calorimeter acceptance

   Ishita Ganguli🇵🇱 · Andreas van Hameren🇵🇱 · Piotr Kotko🇵🇱 · Krzysztof Kutak🇵🇱

   Using the small-$x$ Improved Transverse Momentum Dependent factorization (ITMD), which, for a general two-to-two massless scattering can be proved within the Color Glass Condensate (CGC) theory for transverse momenta of particles greater than the saturation scale, we provide predictions for isolated forward photon and jet production in proton-proton and proton-nucleus collisions within the planned ALICE FoCal detector acceptance. We study azimuthal correlations, $p_T$ spectra, as well as normalized ratios of proton-proton cross sections for different energies. The only TMD distribution needed for that process is the "dipole" TMD gluon distribution, which in our computations is based on HERA data and undergoes momentum space BK evolution equation with DGLAP corrections and Sudakov resummation. We conclude, that the process provides an excellent probe of the dipole TMD gluon distribution in saturation regime.

   hep-phEPJC(2023)·16 citations
3. 03*

   Anomalous and Linear Holographic Hard Wall Models for Glueballs and the Pomeron

   Rafael A. Costa-Silva🇧🇷 · Henrique Boschi-Filho🇧🇷

   In this work we propose improved holographic hard wall (HW) models by the inclusion of anomalous dimensions in the dual operators that describe glueballs inspired by the AdS/CFT correspondence. The anomalous dimensions come from well known semi-classical gauge/string duality analysis showing a dependence with the logarithm of spin $S$ of the boundary states. We show that these logarithm anomalous dimensions of the high spin operators combined with the usual HW model allow us to match the pomeron trajectory and give glueball masses which are better than that of the original HW and soft wall (SW) models in comparison with lattice data. We also build up other anomalous HW (AHW) models considering that the logarithm anomalous dimensions can be approximated by a truncated series of odd powers of the difference $\sqrt{S}-1/\sqrt{S}$. These models also fit the pomeron trajectory and produce good glueball masses. Then, we consider an anomalous dimension which is proportional to $\sqrt{S}$, providing reasonable results. Finally, we propose an asymptotic linear AHW model which effective dimensions for high spins operators are of the form $\Delta =a\sqrt{S}+b$, where $a$ and $b$ are constants to be fixed by comparison with the soft pomeron trajectory. In this last model, the Regge trajectory is asymptotically linear even for very high spins ($J\sim 100$) matching the soft pomeron trajectory accurately and generates glueball masses with deviations with respect to the lattice data better than the original HW and SW models.

   hep-phhep-thPRD(2024)·2 citations
4. 04*

   Form factors of ${\Omega }^{-}$ in a covariant quark-diquark approach

   Dongyan Fu🇨🇳 · JiaQi Wang🇨🇳 · Yubing Dong🇨🇳

   The electromagnetic and gravitational form factors of ${\Omega }^{-}$, a spin-3/2 hyperon composed of three $s$ quarks, are calculated by using a covariant quark-diquark approach. The model parameters are determined by fitting to the form factors of the lattice QCD calculations. Our obtained electromagnetic radii, magnetic moment, and electric-quadrupole moment are in agreement with the experimental measurements and some other model calculations. Furthermore, the mass and spin distributions of ${\Omega }^{-}$ from the gravitational form factors are also displayed. It is found that the mass radius is smaller than its electromagnetic ones. Finally, the interpretations of the energy density and momentum current distribution are also discussed.

   hep-phPRD(2023)·12 citations
5. 05*

   The 3+1D initialization and evolution of the Glasma

   Scott McDonald🇨🇦 · Sangyong Jeon🇨🇦 · Charles Gale🇨🇦

   The IP-Glasma initial condition has been highly successful in the phenomenology of ultra-relativistic heavy ion collisions. The assumption of boost invariance, however, while good for collision energies probed at the LHC, limits the use of IP-Glasma to the transverse dynamics of heavy ion collision to near mid-rapidity. There is a wealth of physics to be explored and understood in the longitudinal dynamics of heavy ion collisions, and a full understanding of heavy ion collisions can only come from 3-dimensional studies. In particular, long range rapidity correlations are seeded in the initial collision and provide additional information on the high energy nuclear wave functions that has thus far been inaccessible to the IP-Glasma model. In this work, we introduce a way to extend the IP-Glasma model to 3+1-dimensions while preserving its key features.

   hep-phnucl-thPRC(2023)·34 citations
6. 06*

   Prospects for charged Higgs bosons in natural SUSY models at the high-luminosity LHC

   Howard Baer🇺🇸 · Vernon Barger🇺🇸 · Xerxes Tata🇺🇸 · Kairui Zhang🇺🇸

   We continue our examination of prospects for discovery of heavy Higgs bosons of natural SUSY (natSUSY) models at the high luminosity LHC (HL-LHC), this time focussing on charged Higgs bosons. In natSUSY, higgsinos are expected at the few hundred GeV scale whilst electroweak gauginos inhabit the TeV scale and the heavy Higgs bosons, H, A and H^\pm could range up tens of TeV without jeopardizing naturalness. For TeV-scale heavy SUSY Higgs bosons H, A and H^\pm, as currently required by LHC searches, SUSY decays into gaugino plus higgsino can dominate H^\pm decays provided these decays are kinematically accessible. The visible decay products of higgsinos are soft making them largely invisible, whilst the gauginos decay to W, Z or h plus missing transverse energy (MET). Charged Higgs bosons are dominantly produced at LHC14 via the parton subprocess, gb-> H^\pm t. In this paper, we examine the viability of observing signtures from H^\pm -> \tau\nu, H^\pm -> tb and H^\pm -> W, Z, h + MET events produced in association with a top quark at the HL-LHC over large Standard Model (SM) backgrounds from (mainly) t\bar{t}, t\bar{t}V and t\bar{t}h production (where V=W, Z). We find that the greatest reach is found via the SM H^\pm(-> \tau\nu) +t channel with a subdominant contribution from the H^\pm(-> tb) +t channel. Unlike for neutral Higgs searches, the SUSY decay modes appear to be unimportant for H^\pm searches at the HL-LHC. We delineate regions of the m_A vs. \tan\beta plane, mostly around m_A \sim 1-2 TeV, where signals from charged Higgs bosons would serve to confirm signals of a heavy, neutral Higgs boson at the 5\sigma level or, alternatively, to exclude heavy Higgs bosons at the 95% confidence level at the high luminosity LHC.

   hep-phSymmetry(2023)·4 citations
7. 07*

   Probing Dual NSI and CP Violation in DUNE and T2HK

   Barnali Brahma🇮🇳 · Anjan Giri🇮🇳

   The latest results from the long baseline neutrino experiments show a hint of non-zero CP violation in the neutrino sector. In this article, we study the CP violation effects in the upcoming long-baseline neutrino experiments DUNE and T2HK. Non-standard interactions can affect the cleaner determination of CP violation parameter. It has been argued that the NSI can help alleviate the tension between the recent ${\delta }_{CP}$ measurements of NO$\nu$A and T2K experiments. We consider here the dual NSI due to ${ϵ}_{e\mu }$ and ${ϵ}_{e\tau }$, arising simultaneously to see the effects in neutrino oscillation probabilities. Moreover, the CP asymmetry parameter $A_{CP}$ exhibits a clear distinction between normal and inverted mass orderings in the DUNE experiment.

   hep-ph5 citations
8. 08*

   Pseudoscalar meson dominance and nucleon structure

   Enrique Ruiz Arriola🇪🇸 · Pablo Sanchez-Puertas🇪🇸

   Pseudoscalar meson dominance has implications for nucleon structure which follow from an Extended Partial Conservation of the Axial Current (EPCAC). The minimal resonance saturation of the nucleon pseudoscalar form factor of the lowest pseudoscalar and isovector mesons compatible with pQCD short distance constraints and chiral symmetry. Using PDG tabulated pseudoscalarisovector masses and widths we obtain $g_{\pi NN}=13.21{(}_{-0.06}^{+0.11})$, to be compared with the most precise determinations from $np,pp$ scattering, $g_{{\pi }^{+}np}=13.25(5)$ from the Granada-2013 database. Equivalently a Goldberger-Treiman discrepancy ${\Delta }_{\mathrm{GT}}=1.8_{-0.4}^{+0.9}\%$ is found. Our results are consistent with almost flat strong pion-nucleon-nucleon vertices.

   hep-phFew Body Syst.(2023)·1 citation
9. 09*

   Using Earth to Search for Long-Range Spin-Velocity Interactions

   Nathan B. Clayburn🇺🇸 · Larry R. Hunter🇺🇸

   Precision measurements of the possible coupling of spin to other scalars, vectors and pseudovectors has proven to be a sensitive way to search for new particle physics beyond the standard model. Indeed, in addition to searching for exotic spin-spin interactions, studies have been undertaken to look for couplings of spin to gravity, the relative velocity between particles, and preferred directions. Several laboratory experiments have established upper bounds on the energy associated with various fermion spin-orientations relative to Earth. Here, we combine these results with a model of Earth in order to investigate the possible long-range spin-velocity interactions associated with the exchange of ultralight ($m_{z^{\prime }}<1$ neV) or massless scalar or vector bosons. We establish stringent bounds on the strength of these couplings between electrons, neutrons, protons and nucleons.

   hep-phphysics.atom-phPRD(2023)·17 citations
10. 10*

    FCNC charmed-hadron decays with invisible singlet particles in light of recent data

    Geng Li🇨🇳 · Jusak Tandean🇨🇳

    The flavor-changing neutral current (FCNC) decays of charmed hadrons with missing energy $(/E)$ can serve as potentially promising hunting grounds for hints of new physics, as the standard-model backgrounds are very suppressed. A few of such processes have been searched for in recent experiments, specifically $D^0\to /E$ by Belle and $D^0\to {\pi }^0$$/E$ and ${\Lambda }_c^{+}\to p/E$ by BESIII, resulting in upper bounds on their branching fractions. We consider them to illuminate the possible contributions of the quark transition $c\to u/E$ with a couple of invisible spinless bosons carrying away the missing energy, assuming that they are not charge conjugates of each other and hence can have unequal masses. We find that these data are complementary in that they constrain different sets of the underlying operators and do not cover the same ranges of the bosons' masses, but there are regions not yet accessible. From the allowed parameter space, we show that other $D$-meson decays, such as $D\to \rho$$/E$, and the charmed-baryon ones ${\Xi }_c\to (\Sigma ,\Lambda )$$/E$ can have sizable branching fractions and therefore may offer further probes of the new-physics interactions. We point out the importance of $D^0\to \gamma /E$ which are not yet searched for but could access parts of the parameter space beyond the reach of the other modes. In addition, we look at a scenario where the invisibles are instead fermionic, namely sterile neutrinos, and a scalar leptoquark mediates $c\to u/E$. We discuss the implications of the aforesaid bounds for this model. The predictions we make for the various charmed-hadron decays in the different scenarios may be testable in the near future by BESIII and Belle II.

    hep-phhep-exJHEP(2023)·8 citations
11. 11*

    Towards distinguishing Dirac from Majorana neutrino mass with gravitational waves

    Stephen F. King🇬🇧 · Danny Marfatia🇺🇸 · Moinul Hossain Rahat🇬🇧

    We propose a new method towards distinguishing the Dirac versus Majorana nature of neutrino masses from the spectrum of gravitational waves (GWs) associated with neutrino mass genesis. Motivated by the principle of generating small neutrino masses without tiny Yukawa couplings, we assume generic seesaw mechanisms for both Majorana and Dirac neutrino masses. For Majorana neutrinos, we further assume a spontaneously broken gauged $U(1{)}_{B-L}$ symmetry, independently of the type of Majorana seesaw mechanism, which gives a cosmic string induced GW signal flat over a wide range of frequencies. For Dirac neutrinos, we assume the spontaneous breaking of a $Z_2$ symmetry, the minimal symmetry choice associated with all Dirac seesaw mechanisms, which is softly broken, generating a peaked GW spectrum from the annihilation of the resulting domain walls. In fact, the GW spectra for all types of Dirac seesaws with such a broken $Z_2$ symmetry are identical, subject to a mild caveat. As an illustrative example, we study the simplest respective type-I seesaw mechanisms, and show that the striking difference in the shapes of the GW spectra can help differentiate between these Dirac and Majorana seesaws, complementing results of neutrinoless double beta decay experiments. We also discuss detailed implications of the recent NANOGrav data for Majorana and Dirac seesaw models.

    hep-phastro-ph.COhep-exPRD(2024)·65 citations
12. 12*

    Baryon asymmetry from dark matter decay in the vicinity of a phase transition

    Debasish Borah🇮🇳 · Arnab Dasgupta🇺🇸 · Matthew Knauss🇺🇸 · Indrajit Saha🇮🇳

    We propose a novel framework where baryon asymmetry of the universe can arise due to forbidden decay of dark matter (DM) enabled by finite-temperature effects in the vicinity of a first order phase transition (FOPT). In order to implement this novel cogenesis mechanism, we consider the extension of the standard model by one scalar doublet $\eta$, three right handed neutrinos (RHN), all odd under an unbroken $Z_2$ symmetry, popularly referred to as the scotogenic model of radiative neutrino mass. While the lightest RHN $N_1$ is the DM candidate and stable at zero temperature, there arises a temperature window prior to the nucleation temperature of the FOPT assisted by $\eta$, where $N_1$ can decay into $\eta$ and leptons generating a non-zero lepton asymmetry which gets converted into baryon asymmetry subsequently by sphalerons. The requirement of successful cogenesis together with a first order electroweak phase transition not only keep the mass spectrum of new particles in sub-TeV ballpark within reach of collider experiments but also leads to observable stochastic gravitational wave spectrum which can be discovered in planned experiments like LISA.

    hep-phastro-ph.COPRD(2023)·11 citations
13. 13*

    Neff in the Standard Model at NLO is 3.043

    Mattia Cielo🇮🇹 · Miguel Escudero🇨🇭 · Gianpiero Mangano🇮🇹 · Ofelia Pisanti🇮🇹

    The effective number of relativistic neutrino species is a fundamental probe of the early Universe and its measurement represents a key constraint on many scenarios beyond the Standard Model of Particle Physics. In light of this, an accurate prediction of $N_{\mathrm{eff}}$ in the Standard Model is of pivotal importance. In this work, we consider the last ingredient needed to accurately calculate $N_{\mathrm{eff}}^{\mathrm{SM}}$: standard zero and finite temperature QED corrections to $e^{+}{e}^{-}\leftrightarrow \nu \bar{\nu }$ interaction rates during neutrino decoupling at temperatures around $T\sim \mathrm{MeV}$. We find that this effect leads to a reduction of $-0.0007$ in $N_{\mathrm{eff}}^{\mathrm{SM}}$. This NLO QED correction to the interaction rates, together with finite temperature QED corrections to the electromagnetic density of the plasma, and the effect of neutrino oscillations, implies that $N_{\mathrm{eff}}^{\mathrm{SM}}=3.043$ with a theoretical uncertainty that is much smaller than any projected observational sensitivity.

    hep-phastro-ph.COPRD(2023)·111 citations
14. 14*

    Momentum-space second-order pion-nucleus potential including medium effects in the $\Delta (1232)$ region

    Viacheslav Tsaran🇩🇪 · Marc Vanderhaeghen🇩🇪

    In this work, we develop an updated model for pion-nucleus scattering in the framework of the distorted wave impulse approximation in momentum space. We construct the second-order pion-nucleus potential, which involves analysis of pion-nucleus elastic scattering as a solution of the Lippmann-Schwinger equation. The potential is based on the individual pion-nucleon scattering amplitudes extracted from SAID, and its second-order correction is presented in detail. We estimate optimal energy-independent parameters of the potential by a multi-energy fit of the pion-${}^{12}$C total, reaction, and differential elastic cross sections. We show the predictive power by applying it to pion elastic scattering on ${}^{16}$O, ${}^{28}$Si, and ${}^{40}$Ca.

    ↳ nucl-thhep-phPRC(2023)·4 citations
15. 15*

    Quantum-spacetime effects on nonrelativistic Schrödinger evolution

    Fabian Wagner🇵🇱 · Gislaine Varão🇧🇷 · Iarley P. Lobo🇧🇷 · Valdir B. Bezerra🇧🇷

    The last three decades have witnessed the surge of quantum gravity phenomenology in the ultraviolet regime as exemplified by the Planck-scale accuracy of time-delay measurements from highly energetic astrophysical events. Yet, recent advances in precision measurements and control over quantum phenomena may usher in a new era of low-energy quantum gravity phenomenology. In this study, we investigate relativistic modified dispersion relations (MDRs) in curved spacetime and derive the corresponding nonrelativistic Schrödinger equation using two complementary approaches. First, we take the nonrelativistic limit, and canonically quantise the result. Second, we apply a WKB-like expansion to an MDR-inspired deformed relativistic wave equation. Both approaches imply equivalent results for single-particle quantum mechanics. Based on a map between our approach and the generalized uncertainty principle (GUP), we recognise in the latter the MDR which is least amenable to low-energy experiments. Consequently, importing data from time-delay measurements, we constrain the linear GUP up to the Planck scale and improve on current bounds to the quadratic one by 17 orders of magnitude. MDRs with larger implications in the infrared, however, can be tightly constrained in the nonrelativistic regime, from which we use the ensuing deviation from the equivalence principle to bound some MDRs to up to one order of magnitude below the Planck scale, while constraining those customarily associated with the bicrossproduct basis of the $\kappa$-Poincaré algebra to energy scales beyond $10^{15}$GeV.

    ↳ gr-qchep-phhep-thPRD(2023)·20 citations
16. 16*

    Chiral EFT calculation of neutrino reactions in warm neutron-rich matter

    Eunkyoung Shin🇺🇸 · Ermal Rrapaj🇺🇸 · Jeremy W. Holt🇺🇸 · Sanjay K. Reddy🇺🇸

    Neutrino scattering and absorption rates of relevance to supernovae and neutron star mergers are obtained from nuclear matter dynamical structure functions that encode many-body effects from nuclear mean fields and correlations. We employ nuclear interactions from chiral effective field theory to calculate the density, spin, isospin, and spin-isospin response functions of warm beta-equilibrium nuclear matter. We include corrections to the single-particle energies in the mean field approximation as well as vertex corrections resummed in the random phase approximation (RPA), including, for the first time, both direct and exchange diagrams. We find that correlations included through the RPA redistribute the strength of the response to higher energy for neutrino absorption and lower energy for antineutrino absorption. This tends to suppress the absorption rate of electron neutrinos across all relevant energy scales. In contrast, the inclusion of RPA correlations enhances the electron antineutrino absorption rate at low energy and supresses the rate at high energy. These effects are especially important at high-density and in the vicinity of the neutrino decoupling region. Implications for heavy element nucleosynthesis, electromagnetic signatures of compact object mergers, supernova dynamics, and neutrino detection from galactic supernovae are discussed briefly.

    ↳ nucl-thastro-ph.HEhep-phPRC(2024)·12 citations
17. 17*

    Physics of the Analytic S-Matrix

    Sebastian Mizera🇺🇸

    You might've heard about various mathematical properties of scattering amplitudes such as analyticity, sheets, branch cuts, discontinuities, etc. What does it all mean? In these lectures, we'll take a guided tour through simple scattering problems that will allow us to directly trace such properties back to physics. We'll learn how different analytic features of the S-matrix are really consequences of causality, locality of interactions, unitary propagation, and so on. These notes are based on a series of lectures given in Spring 2023 at the Institute for Advanced Study in Princeton and the Higgs Centre School of Theoretical Physics in Edinburgh.

    ↳ hep-thhep-phquant-phPhys.Rept.(2024)·62 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.