Mon·Oct 5, 2020Monday·October 5, 2020

1. 01*

   Quantum Entanglement and Thermal Behavior in Charged-Current Weak Interactions

   G. Iskander🇺🇸 · J. Pan🇨🇦 · M. Tyler🇺🇸 · C. Weber🇺🇸 · O.K. Baker🇺🇸

   We show that quantum entanglement between causally separated regions of a nucleon in antineutrino-nucleon scattering manifests itself as a thermal component in the resulting pion momentum distribution. For antineutrino scattering coherently from the (carbon) nucleus as a whole, this thermal component is absent, as expected by our quantum entanglement thermalization proposition. These phenomena, which have been observed in proton-proton collisions at the Large Hadron Collider, and in electromagnetic deep inelastic scattering, are now for the first time shown to exist in electroweak interactions as well.

   hep-phquant-phPLB(2020)·15 citations
2. 02*

   Parameterisation space for Cornell potential in a QCD potential model

   Krishna Kingkar Pathak · Satyadeep Bhattacharya · Tapashi Das

   We make a critical analysis on the free parameters of the Cornell potential $-4{\alpha }_s/3r+br+c$ and provide a parameterisation space for the strong coupling constant ${\alpha }_s$ and the constant shift $c$ for choosing linear part as perturbation in the potential model. In the analysis of heavy-light mesons $(D,D_s,B,B_s\text{and}{B}_c)$, we have found a wide range of values for the coupling constant i.e $0.20\le {\alpha }_s\le 0.64$ with $-1.2\le c\le -0.66$ which can be used to treat the confining part as perturbation.

   hep-phEPJC(2022)·12 citations
3. 03*

   Direct-channel option of the forward slope increase

   S.M. Troshin🇷🇺 · N.E. Tyurin🇷🇺

   The LHC data on the elastic scattering indicate that the forward slope increase is not consistent with the contributions of the simple Regge poles only with the linear Regge trajectories. The dynamics might be associated with unitarization in the direct channel of reaction. We discuss the problems of the Regge model and provide a respective illustration of the direct-channel option.

   hep-phParticles(2021)·3 citations
4. 04*

   The Origin of Hadron Masses

   Ying Chen🇨🇳

   The color confinement can be decently explained by assuming the global $SU(3)$ color symmetry. A hadron is viewed as a bag of a finite size, whose energy is contributed by the color fields within the hadron. In the large momentum frame, the mass of a hadron can be quantized and can be expressed as the sum of the current masses of quarks involved plus a flavor independent term which depends on a universal parameter and can be identified to be the contribution from the QCD trace anomaly. This term depicts the Regge's trajectories of light hadron masses, from which the parameter can be determined and gives the minimal vector meson mass and baryon mass to be 761 MeV and 935 MeV, respectively. The mass formula can explain many features of the hadron spectroscopy.

   hep-phhep-ex4 citations
5. 05*

   Equation of state of strongly magnetized matter with hyperons and $\Delta$-resonances

   Vivek Baruah Thapa🇮🇳 · Monika Sinha🇮🇳 · Jia-Jie Li🇨🇳 · Armen Sedrakian🇩🇪

   We construct a new equation of state for the baryonic matter under an intense magnetic field within the framework of covariant density functional theory. The composition of matter includes hyperons as well as $\Delta$-resonances. The extension of the nucleonic functional to the hypernuclear sector is constrained by the experimental data on $\Lambda$ and $\Xi$-hypernuclei. We find that the equation of state stiffens with the inclusion of the magnetic field, which increases the maximum mass of neutron star compared to the non-magnetic case. In addition, the strangeness fraction in the matter is enhanced. Several observables, like the Dirac effective mass, particle abundances, etc show typical oscillatory behavior as a function of the magnetic field and/or density which is traced back to the occupation pattern of Landau levels.

   hep-phastro-ph.HEnucl-thParticles(2020)·37 citations
6. 06*

   Local Unitarity: a representation of differential cross-sections that is locally free of infrared singularities at any order

   Zeno Capatti🇨🇭 · Valentin Hirschi🇨🇭 · Andrea Pelloni🇨🇭 · Ben Ruijl🇨🇭

   We propose a novel representation of differential scattering cross-sections that locally realises the direct cancellation of infrared singularities exhibited by its so-called real-emission and virtual degrees of freedom. We take advantage of the Loop-Tree Duality representation of each individual forward-scattering diagram and we prove that the ensuing expression is locally free of infrared divergences, applies at any perturbative order and for any process without initial-state collinear singularities. Divergences for loop momenta with large magnitudes are regulated using local ultraviolet counterterms that reproduce the usual Lagrangian renormalisation procedure of quantum field theories. Our representation is especially suited for a numerical implementation and we demonstrate its practical potential by computing fully numerically and without any IR counterterm the next-to-leading order accurate differential cross-section for the process $e^{+}{e}^{-}\to d\bar{d}$. We also show first results beyond next-to-leading order by computing interference terms part of the N4LO-accurate inclusive cross-section of a $1\to 2+X$ scalar scattering process.

   hep-phhep-thJHEP(2021)·69 citations
7. 07*

   Stellar limits on light CP-even scalar

   P. S. Bhupal Dev🇺🇸 · Rabindra N. Mohapatra🇺🇸 · Yongchao Zhang🇨🇳

   We revisit the astrophysical constraints on a generic light CP-even scalar particle $S$, mixing with the Standard Model (SM) Higgs boson, from observed luminosities of the Sun, red giants, white dwarfs and horizontal-branch stars. The production of $S$ in the stellar core is dominated by the electron-nuclei bremsstrahlung process $e+N\to e+N+S$. With the $S$ decay and reabsorption processes taken into consideration, we find that the stellar luminosity limits exclude a broad range of parameter space in the $S$ mass-mixing plane, with the scalar mass up to 350 keV and the mixing angle ranging from $7.0\times 10^{-18}$ to $3.4\times 10^{-3}$. We also apply the stellar limits to a real-singlet scalar extension of the SM, where we can relate the mixing angle to the parameters in the scalar potential. In both the generic scalar case and the real-singlet extension, we show that the stellar limits preclude the scalar interpretation of the recently observed XENON1T excess in terms of the $S$ particles emitted from the Sun.

   hep-phastro-ph.SRJCAP(2021)·28 citations
8. 08*

   GUT Baryogenesis With Primordial Black Holes

   Dan Hooper🇺🇸 · Gordan Krnjaic🇺🇸

   In models of baryogenesis based on Grand Unified Theories (GUTs), the baryon asymmetry of the universe is generated through the CP and baryon number violating, out-of-equilibrium decays of very massive gauge or Higgs bosons in the very early universe. Recent constraints on the scale of inflation and the subsequent temperature of reheating, however, have put pressure on many such models. In this paper, we consider the role that primordial black holes may have played in the process of GUT baryogenesis. Through Hawking evaporation, black holes can efficiently generate GUT Higgs or gauge bosons, regardless of the masses of these particles or the temperature of the early universe. Furthermore, in significant regions of parameter space, the black holes evaporate after the electroweak phase transition, naturally evading the problem of sphaleron washout that is normally encountered in GUT models based on $SU(5)$. We identify a wide range of scenarios in which black holes could facilitate the generation of the baryon asymmetry through the production and decays of GUT bosons.

   hep-phastro-ph.COPRD(2021)·100 citations
9. 09*

   Jet Wake from Linearized Hydrodynamics

   Jorge Casalderrey-Solana🇪🇸 · José Guilherme Milhano🇵🇹 · Daniel Pablos🇳🇴 · Krishna Rajagopal🇺🇸 · Xiaojun Yao🇺🇸

   We explore how to improve the hybrid model description of the particles originating from the wake that a jet produced in a heavy ion collision leaves in the droplet of quark-gluon plasma (QGP) through which it propagates, using linearized hydrodynamics on a background Bjorken flow. Jet energy and momentum loss described by the hybrid model become currents sourcing linearized hydrodynamics. By solving the linearized hydrodynamic equations numerically, we investigate the development of the wake in the dynamically evolving droplet of QGP, study the effect of viscosity, scrutinize energy-momentum conservation, and check the validity of the linear approximation. We find that linearized hydrodynamics works better in the viscous case because diffusive modes damp the energy-momentum perturbation produced by the jet. We calculate the distribution of particles produced from the jet wake by using the Cooper-Frye prescription and find that both the transverse momentum spectrum and the distribution of particles in azimuthal angle are similar in shape in linearized hydrodynamics and in the hybrid model. Their normalizations are different because the momentum-rapidity distribution in the linearized hydrodynamics analysis is more spread out, due to sound modes. Since the Bjorken flow has no transverse expansion, we explore the effect of transverse flow by using local boosts to add it into the Cooper-Frye formula. After including the effects of transverse flow in this way, the transverse momentum spectrum becomes harder: more particles with transverse momenta bigger than $2$ GeV are produced than in the hybrid model. Although we defer implementing this analysis in a jet Monte Carlo, as would be needed to make quantitative comparisons to data, we gain a qualitative sense of how the jet wake may modify jet observables by computing proxies for two example observables: the lost energy recovered in a cone of varying open angle, and the fragmentation function. We find that linearized hydrodynamics with transverse flow effects added improves the description of the jet wake in the hybrid model in just the way that comparison to data indicates is needed. Our study illuminates a path to improving the description of the wake in the hybrid model, highlighting the need to take into account the effects of both transverse flow and the broadening of the energy-momentum perturbation in spacetime rapidity on particle production.

   hep-phnucl-thJHEP(2021)·64 citations
10. 10*

    A hybrid simulation of gravitational wave production in first-order phase transitions

    Ryusuke Jinno🇩🇪 · Thomas Konstandin🇩🇪 · Henrique Rubira🇩🇪

    The LISA telescope will provide the first opportunity to probe the scenario of a first-order phase transition happening close to the electroweak scale. By now, it is evident that the main contribution to the GW spectrum comes from the sound waves propagating through the plasma. Current estimates of the GW spectrum are based on numerical simulations of a scalar field interacting with the plasma or on analytical approximations -- the so-called sound shell model. In this work we present a novel setup to calculate the GW spectra from sound waves. We use a hybrid method that uses a 1d simulation (with spherical symmetry) to evolve the velocity and enthalpy profiles of a single bubble after collision and embed it in a 3d realization of multiple bubble collisions, assuming linear superposition of the velocity and enthalpy. The main advantage of our method compared to 3d hydrodynamic simulations is that it does not require to resolve the scale of bubble wall thickness. This makes our simulations more economical and the only two relevant physical length scales that enter are the bubble size and the shell thickness (that are in turn enclosed by the box size and the grid spacing). The reduced costs allow for extensive parameter studies and we provide a parametrization of the final GW spectrum as a function of the wall velocity and the fluid kinetic energy.

    ↳ astro-ph.COhep-phJCAP(2021)·79 citations
11. 11*

    Constraints on the epoch of dark matter formation from Milky Way satellites

    Subinoy Das🇮🇳 · Ethan O. Nadler🇺🇸

    A small fraction of thermalized dark radiation that transitions into cold dark matter (CDM) between big bang nucleosynthesis and matter-radiation equality can account for the entire dark matter relic density. Because of its transition from dark radiation, "late-forming dark matter" (LFDM) suppresses the growth of linear matter perturbations and imprints the oscillatory signatures of dark radiation perturbations on small scales. The cutoff scale in the linear matter power spectrum is set by the redshift $z_T$ of the phase transition; tracers of small-scale structure can therefore be used to infer the LFDM formation epoch. Here, we use a forward model of the Milky Way (MW) satellite galaxy population to address the question: How late can dark matter form? For dark radiation with strong self-interactions, which arises in theories of neutrinolike LFDM, we report $z_T>5.5\times 10^6$ at $95\%$ confidence based on the abundance of known MW satellite galaxies. This limit rigorously accounts for observational incompleteness corrections, marginalizes over uncertainties in the connection between dwarf galaxies and dark matter halos, and improves upon galaxy clustering and Lyman-$\alpha$ forest constraints by nearly an order of magnitude. We show that this limit can also be interpreted as a lower bound on $z_T$ for LFDM that free-streams prior to its phase transition, although dedicated simulations will be needed to analyze this case in detail. Thus, dark matter created by a transition from dark radiation must form no later than one week after the big bang.

    ↳ astro-ph.COastro-ph.GAhep-phPRD(2021)·33 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.