119072276
Quantum rearrangement and self-consistent BCS-BEC crossover thermodynamics
Based on previous works, analytical calculational procedures for dealing with the strongly interacting fermion ground state are further developed through a medium-dependent potential in terms of the Bethe-Peierls contact interaction model. The methods are exact in the unitary limit regime and they lead to self-consistent equations analogous to the Hartree ones. The single particle energy spectrum rearrangement effects on the thermodynamics due to the Hugenholtz\char21{}van Hove theorem constraint are addressed. These effects lead to an additional instantaneous correlation potential contribution to the system physical chemical potential and pressure, i.e., equation of state, in order to enforce the classical thermodynamic consistency. The Dyson-Schwinger equations represent implicitly the various Bethe-Goldstone expansion ones. In a thermodynamically self-consistent way, the universal dimensionless factor is analytically calculated to be $\ensuremath{\xi}=\frac{4}{9}$, which defines the ratio of the unitary fermions energy density to that of the ideal noninteracting ones at $T=0$.
125706576
Novel effects of electromagnetic interaction on the correlation of nuclear matter
122544309
THE MULTI-VALUE OF EFFECTIVE NUCLEON MASS IN HOT/DENSE NUCLEAR MATTER AND THE PHASE TRANSITION
From the Lagrangian of QHD-I model, we investigate the effective nucleon mass under the mean field approximation in a wide temperature region. The multi-solution of self-consistent equation for the effective mass in found. In the high temperature region, the relation between the multi-solutions and the phase transition is analyzed. Furthermore, the variation of energy density in this region is studied.
119453402
1S0 pairing correlation in symmetric nuclear matter with Debye screening effects
Abstract The 1 S 0 pairing of symmetric nuclear matter is discussed in the framework of relativistic nuclear theory with Dyson–Schwinger equations (DSEs). The in-medium nucleon and meson propagators are treated in a more self-consistent way through meson polarizations. The screening effects on mesons due to in-medium nucleon excitation are found to reduce the 1 S 0 pairing gap and shift remarkably the gap peak to low density region.
124840820
Finite-temperature nuclear matter properties within a relativistic σ − ω coupling model
We use the relativistic mean field theory to study the finite temperature nuclear matter properties. The effects of isoscalar $\ensuremath{\sigma}\text{\ensuremath{-}}\ensuremath{\omega}$ coupling on the equation of state and finite temperature properties of symmetric and asymmetric nuclear matter are investigated carefully. For comparison, we also discuss the properties of two nonlinear $\ensuremath{\sigma}$ self-coupling models, namely NL-SH and NL3. It is found that the $\ensuremath{\sigma}\text{\ensuremath{-}}\ensuremath{\omega}$ coupling term can soften the equation of state, but has very limited influence to the critical temperature of the nuclear matter liquid-gas phase transition.
124341359
Thomson Problem approach to relativistic Dirac fermions ground state energy in the unitary limit
118576689
{pi}{pi} scattering in twisted mass chiral perturbation theory
In this report we describe both I=2 and I=0 {pi}{pi} scattering for twisted mass lattice QCD utilizing twisted mass chiral perturbation theory at next-to-leading order. Focusing on the lattice spacing (b) corrections, we demonstrate that in the exotic I=2, I{sub 3}={+-}2 channels ({pi}{sup {+-}}{pi}{sup {+-}}), the leading scaling violations of {pi}{pi} scattering at maximal twist begin at O(m{sub {pi}}{sup 2}b{sup 2}). This is not the case in any other isospin channel, for which the scaling violations at maximal twist begin at O(b{sup 2}). Furthermore, we demonstrate the existence of a mixing between the I=2, I{sub 3}=0 and I=0 scattering channels due to the breaking of isospin symmetry by the twisted mass term. The mixing term, although formally next-to-leading order, is relatively large, thus necessitating the use of a coupled channel analysis. We argue that this mixing likely renders the computation of the I=0 channel impractical with twisted mass lattice QCD.
118416435
Shear viscosity of a gluon plasma in perturbative QCD
Abstract We calculate the shear viscosity ( η ) to entropy density ( s ) ratio η / s of a gluon plasma in kinetic theory including the g g → g g and g g → g g g processes. Due to the suppressed contribution to η in the g g → g g forward scattering, it is known that the gluon bremsstrahlung g g ↔ g g g process also contributes at the same order ( O ( α s − 2 ) ) in perturbative QCD. Using the Gunion–Bertsch formula for the g g → g g g matrix element which is valid for the limit of soft bremsstrahlung, we find that the result is sensitive to whether the same limit is taken for the phase space. Using the exact phase space, the g g ↔ g g g contribution becomes more important to η than g g → g g for α s ≳ 2 × 10 − 3 . Therefore, at α s = 0.1 , η / s ≃ 1.0 , between 2.7 obtained by Arnold, Moore and Yaffe (AMY) and 0.5 obtained by Xu and Greiner (XG). If the soft bremsstrahlung limit is imposed on the phase space such that the recoil effect from the bremsstrahlung gluon is neglected, then the correction from the g g ↔ g g g process is about 10–30% of the total which is close to AMY's prediction. This shows that further studies beyond the soft bremsstrahlung approximation used by XG and collinear approximation used by AMY are needed.
122417032
Hypernucleus physics at RHIC
Abstract We report recent progress in hypernucleus studies measured by the STAR collaboration at the Relativistic Heavy Ion Collider. We show a preliminary hypertriton measurement from our current event sample and discuss the next step for this project.
122034006
Neutrino deuteron scattering in effective field theory
119342728
Deuteron Compton scattering in effective field theory : Spin-dependent cross sections and asymmetries
Polarized Compton scattering on the deuteron is studied in nuclear effective field theory. A set of tensor structures is introduced to define 12 independent Compton amplitudes. The scalar and vector amplitudes are calculated up to next-to-next-to-leading order in low-energy power counting. Significant contribution to the vector amplitudes is found to come from the spin-orbit type of relativistic corrections. A double-helicity-dependent cross section {delta}{sub 1}d{sigma}/d{omega}=(d{sigma}{sub +1-1}-d{sigma}{sub +1+1})/2d{omega} is calculated to the same order, and the effect of the nucleon isoscalar spin-dependent polarizabilities is found to be smaller than the effect of isoscalar spin-independent ones. Contributions of spin-independent polarizabilities are investigated in various asymmetries, one of which has an effect as large as 12% (26%) at the center-of-mass photon energy 30 (50) MeV.