Nuclear Theory·nucl-th

Wednesday·July 31, 2019

9 papers—3 primary·6 cross-listed

01
Hadron matter in neutron stars in view of gravitational wave observations
Felipe J. Llanes-Estrada🇪🇸 · Eva Lope-Oter (Universidad Complutense de Madrid)🇪🇸
In this review we highlight a few physical properties of neutron stars and their theoretical treatment inasmuch as they can be useful for nuclear and particle physicists concerned with matter at finite density (and newly, temperature). Conversely, we lay out some of the hadron physics necessary to test General Relativity with binary mergers including at least one neutron star, in view of the event GW170817: neutron stars and their mergers reach the highest matter densities known, offering access to the matter side of Einstein's equations. In addition to minimum introductory material for those interested in starting research in the field of neutron stars, we dedicate quite some effort to a discussion of the Equation of State of hadron matter in view of gravitational wave developments; we address phase transitions and how the new data may help; we show why transport is expected to be dominated by turbulence instead of diffusion through most if not all of the star, in view of the transport coefficients that have been calculated from microscopic hadron physics; and we relate many of the interesting physics topics in neutron stars to the radius and tidal deformability.
nucl-thastro-ph.HEgr-qcPPNP(2019)·24 citations
02
Production of multi-charmed hadrons by recombination in heavy ion collisions
Sungtae Cho🇰🇷 · Su Houng Lee🇰🇷
We study the production of multi-charmed hadrons by recombination in heavy ion collisions by focusing on the production of $Ξ_{cc}$ , $Ξ_{cc}^{*}$ , $Ω_{scc}$ , $Ω_{scc}^{*}$ , $Ω_{ccc}$ baryons and X(3872) mesons. Starting from the estimation of yields for those hadrons at chemical freeze-out in both the statistical and coalescence model, we evaluate their transverse momentum distributions at mid-rapidity in the coalescence model. We show that yields of multi-charmed hadrons in heavy ion collisions at RHIC and LHC are large enough, and thereby not only multi-charmed hadrons observed so far, e.g., the $Ξ_{cc}$ but also those which have not been observed yet, can be discovered sufficiently in heavy ion collisions. We also find that the transverse momentum distribution ratio between various multi-charmed hadrons sensitively reflects the interplay between quark contents of corresponding hadrons as well as the transverse momentum distribution of charm quarks at the hadronization point, and therefore we insist that studying both the transverse momentum distributions of multi-charmed hadrons themselves and transverse momentum distribution ratios between various multi-charmed hadrons provide us with useful information on hadron production mechanism involving charm quarks in heavy ion collisions.
nucl-thhep-phnucl-exPRC(2020)·29 citations
03
Domain walls in neutron $^{3} P_{2}$ superfluids in neutron stars
Shigehiro Yasui🇯🇵 · Muneto Nitta🇯🇵
We work out domain walls in neutron $^{3} P_{2}$ superfluids realized in the core of neutron stars. Adopting the Ginzburg-Landau (GL) theory as a bosonic low-energy effective theory, we consider configurations of domain walls interpolating ground states, i.e., the uniaxial nematic (UN), D $_{2}$ -biaxial nematic (D $_{2}$ -BN), and D $_{4}$ -biaxial nematic (D $_{4}$ -BN) phases in the presence of zero, small and large magnetic fields, respectively. We solve the Euler-Lagrange equation from the GL free energy density, and calculate surface energy densities of the domain walls. We find that one extra Nambu-Goldstone mode is localized in the vicinity of a domain wall in the UN phase while a U(1) symmetry restores in the vicinity of one type of domain wall in the D $_{2}$ -BN phase and all domain walls in the D $_{4}$ -BN phase. Considering a pile of domain walls in the neutron stars, we find that the most stable configurations are domain walls perpendicular to the magnetic fields piled up in the direction along the magnetic fields in the D $_{2}$ -BN and D $_{4}$ -BN phases. We estimate the energy released from the deconstruction of the domain walls in the edge of a neutron star, and show that it can reach an astrophysical scale such as glitches in neutron stars.
nucl-thastro-ph.HEhep-phhep-thPRC(2020)·17 citations
04
LIght scalars with lepton number to solve the $(g - 2)_{e}$ anomaly
Susan Gardner🇺🇸 · Xinshuai Yan🇺🇸
Scalars that carry lepton number can help mediate would-be lepton-number-violating processes, such as neutrinoless double $β$ decay or lepton-scattering-mediated nucleon-antinucleon conversion. Here we show that such new scalars can also solve the anomaly in precision determinations of the fine-structure constant $α$ from atom interferometry and from the electron's anomalous magnetic moment, $a_{e} \equiv (g - 2)_{e} /2$ , by reducing $∣ a_{e} ∣$ . Study of the phenomenological constraints on these solutions favor a doubly-charged scalar with mass below the GeV scale. Significant constraints arise from the measurement of the parity-violating asymmetry in Møller scattering, and we consider the implications of the next-generation MOLLER experiment at Jefferson Laboratory and of an improved $a_{e}$ measurement.
↳ hep-phnucl-thphysics.atom-phPRD(2020)·23 citations
05
Nonlinear causality of general first-order relativistic viscous hydrodynamics
Fábio S. Bemfica (Rio Grande do Norte U.) · Marcelo M. Disconzi (Vanderbilt U.) · Jorge Noronha (Illinois U., Urbana)
Effective theory arguments are used to derive the most general energy-momentum tensor of a relativistic viscous fluid with an arbitrary equation of state (in the absence of other conserved currents) that is first-order in the derivatives of the energy density and flow velocity and does not include extended variables such as in Mueller-Israel-Stewart-like theories. This energy-momentum tensor leads to a causal theory, provided one abandons the usual conventions for the out-of-equilibrium hydrodynamic variables put forward by Landau-Lifshitz and Eckart. In particular, causality requires nonzero out-of-equilibrium energy density corrections and heat flow. Conditions are found to ensure linear stability around equilibrium in flat space-time. We also prove local existence and uniqueness of solutions to the equations of motion. Our causality, existence, and uniqueness results hold in the full nonlinear regime, without symmetry assumptions, in four space-time dimensions, with or without coupling to Einstein's equations, and are mathematically rigorously established. Furthermore, a kinetic theory realization of this energy-momentum tensor is also provided.
↳ gr-qchep-thnucl-thPRD(2019)·238 citations
06
Chirality of $^{135}$ Nd reexamined: Evidence for multiple chiral doublet bands
B.F. Lv🇫🇷 · C. M. Petrache🇫🇷 · Q. B. Chen🇩🇪 · J. Meng🇨🇳 · A. Astier🇫🇷 · E. Dupont🇫🇷 · P. Greenlees🇫🇮 · H. Badran🇫🇮 · T. Calverley🇫🇮 · D. M. Cox🇫🇮 · T. Grahn🇫🇮 · J. Hilton🇫🇮 and 26 other authors
One new pair of positive-parity chiral doublet bands have been identified in the odd- $A$ nucleus $^{135}$ Nd which together with the previously reported negative-parity chiral doublet bands constitute a third case of multiple chiral doublet (M $χ$ D) bands in the $A \approx 130$ mass region. The properties of the M $χ$ D bands are well reproduced by constrained covariant density functional theory and particle rotor model calculations. The newly observed M $χ$ D bands in $^{135}$ Nd represents an important milestone in supporting the existence of M $χ$ D in nuclei.
↳ nucl-exnucl-thPRC(2019)·32 citations
07
Dipole evolution: perspectives for collectivity and $γ^{*}$ A collisions
Christian Bierlich🇸🇪 · Christine O. Rasmussen🇸🇪
The transverse, spatial structure of protons is an area revealing fundamental properties of matter, and provides key input for deeper understanding of emerging collective phenomena in high energy collisions of protons, as well as collisions of heavy ions. In this paper eccentricities and eccentricity fluctuations are predicted using the dipole formulation of BFKL evolution. Furthermore, first steps are taken towards generation of fully exclusive final states of $γ^{*}$ A collisions, by assessing the importance of colour fluctuations in the initial state. Such steps are crucial for the preparation of event generators for a future electron-ion collider. Due to the connection between an impact parameter picture of the proton structure, and cross sections of ep and pp collisions, the model parameters can be fully determined by fits to such quantities, leaving results as real predictions of the model.
↳ hep-phnucl-thJHEP(2019)·22 citations
08
Time Evolution Operators for Periodic SU(3)
P. G. Morrison
We present an outline of a technique to associate certain methods from time optimal quantum control with various transforms on SU(3). Unitary operators are taken from certain time dependent Hamiltonians and transformation laws are derived. A methodological framework for development of solution for these types of problems with a non-simple geometric framework is presented that is generally applicable. We give an expansive overview of the field of SU(3), its meaning, purpose and context within the presented results. Exact solutions for periodic curves on SU(3) are provided, along with the operators and physical framework that surrounds them. A comprehensive review of the literature and established results is given for reference. Discussion is given in full to effective approaches that may be given both to the teaching of the subject, and the development of further results within the science. We conclude the paper with an overview of new avenues of investigation that are opened through the results that are presented.
↳ quant-phnucl-th2 citations
09
Acceleration of the Sn Equations with Highly Anisotropic Scattering using the Fokker-Planck Equation
Japan K. Patel · James S. Warsa · Anil K. Prinja
The discrete ordinates method can model forward-peaked transport problems accurately. However, convergence of discrete ordinates solution can become arbitrarily slow upon use of standard iterative procedures like source iteration and GMRES. Standard zeroth and first moment-based acceleration methods like nonlinear diffusion acceleration and diffusion synthetic acceleration are ineffective in accelerating such problems because these methods do not correct higher order Legendre-moments of angular flux. We explore the idea of using Fokker-Planck as a preconditioner to accelerate forward-peaked transport problems in this paper.
↳ physics.comp-phnucl-th1 citation

Affiliations

first authorsco-authorsvia INSPIRE