118573990
Three-dimensional correlated-fermion phase separation from analysis of the geometric mean of the individual susceptibilities
A quasi-Gaussian approximation scheme is formulated to study the strongly correlated imbalanced Fermions thermodynamics, where the mean-field theory is not applicable. The non-Gaussian correlation effects are understood to be captured by the statistical geometric mean of the individual susceptibilities. In the three-dimensional unitary fermions ground state, a universal nonlinear scaling transformation relates the physical chemical potentials with the individual Fermi kinetic energies. For the partial polarization phase separation to full polarization, the calculated critical polarization ratio is δC = [1−(1−ξ)6/5]/[1+(1−ξ)6/5] ≐ 0.34. ξ = 4/9 gives the ratio of the symmetric ground state energy density to that of the ideal fermion gas.
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.
120698543
The nonlinear spatial damping rate in QGP
Abstract The derivative expansion method has been used to solve the semiclassical kinetic equations of quark-gluon plasma. The nonlinear spatial damping rate, the imaginary part of the wave vector, for the longitudinal secondary color waves in the long wavelength limit has been calculated numerically.
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 $T=0$.
123747624
The Boundary Value Problem and the Nonlinear Spatial Dispersion in Collisionless Quark-Gluon Plasma*
The boundary value problem of the quark-gluon plasma kinetic equations is analyzed by using the derivative expansion method. The dispersion relation in the linear approximation indicates that there is no collisionless spatial damping, but it reflects that the nonlinear interaction between the eigenwaves in it is very important. By taking account of the nonlinear interactions of waves, the resonance condition between the secondary waves and the particles in quark-gluon plasma can be fulfilled which will result in the spatial damping. The nonlinear spatial collisionless damping rate for the longitudinal secondary color waves in the long wavelength limit has been calculated numerically.
119449850
Shear viscosity to entropy density ratio of QCD below the deconfinement temperature
Abstract Using chiral perturbation theory we investigate the QCD shear viscosity ( η ) to entropy density ( s ) ratio below the deconfinement temperature ( ∼ 170 MeV ) with zero baryon number density. It is found that η / s of QCD is monotonically decreasing in temperature ( T ) and reaches 0.6 with estimated ∼ 50 % uncertainty at T = 120 MeV . A naive extrapolation of the leading order result shows that η / s reaches the 1 / 4 π minimum bound proposed by Kovtun, Son, and Starinets using string theory methods at T ∼ 200 MeV . This suggests a phase transition or cross over might occur at T ≲ 200 MeV in order for the bound to remain valid. Also, it is natural for η / s to stay close to the minimum bound around the phase transition temperature as was recently found in heavy ion collisions.
119388686
Constraints on two-body axial currents from reactor antineutrino–deuteron breakup reactions
Abstract We discuss how to reduce theoretical uncertainties in the neutrino–deuteron breakup cross-sections crucial to the Sudbury Neutrino Observatory's efforts to measure the solar neutrino flux. In effective field theory, the dominant uncertainties in all neutrino–deuteron reactions can be expressed through a single, common, isovector axial two-body current parameterized by  L 1, A . After briefly reviewing the status of fixing L 1, A experimentally, we present a constraint on L 1, A imposed by existing reactor antineutrino–deuteron breakup data. This constraint alone leads to an uncertainty of 6–7% at 7 MeV neutrino energy in the cross-sections relevant to the Sudbury Neutrino Observatory. However, more significantly for the Sudbury experiment, the constraint implies an uncertainty of only 0.7% in the ratio of charged to neutral current cross-sections used to verify the existence of neutrino oscillations, at the same energy. This is the only direct experimental constraint from the two-body system, to date, of the uncertainty in these cross-sections.
119272530
Model analysis of thermal UV-cutoff effects on the chiral critical surface at finite temperature and chemical potential
We study the effects of temporal UV-cutoff on the chiral critical surface in hot and dense QCD using a chiral effective model. Recent lattice QCD simulations indicate that the curvature of the critical surface might change toward the direction in which the first-order phase transition becomes stronger on increasing the number of lattice sites. To investigate this effect on the critical surface in an effective model approach, we use the Nambu-Jona-Lasinio model with finite Matsubara frequency summation. We find that the nature of the curvature of the critical surface does not alter appreciably as we decrease the summation number, which is unlike the case that was observed in recent lattice QCD studies. This may suggest that the dependence of chemical potential on the coupling strength or some additional interacting terms such as vector interactions could play an important role at finite density.
123049469
Directed flow measurements from STAR
STAR measurements of v1 for identified particles for Au+Au collisions at = 200 GeV are presented. A negative v1 slope is observed for pions, protons, antiprotons and kaons (K0S) in 10-70% central collisions. For pion v1 slope, the comparison between the current result and available models (RQMD, UrQMD, AMPT, QGSM and hydro model with a tilted source) is made. In 5-30% central collisions, surprisingly sizable difference between v1 of protons and antiprotons is observed. The centrality and energy dependence of proton v1 are also presented. The charged hadron v1 for Cu+Cu collisions at = 22.4 GeV is measured and compared with results obtained previously.
56112288
Residue theorem and summing over Kaluza-Klein excitations
Applying the equations of motion together with corresponding boundary conditions of bulk profiles at infrared and ultraviolet branes, we verify some lemmas on the eigenvalues of Kaluza-Klein modes in extension of the standard model with a warped extra dimension and the custodial symmetry SU(3){sub c}xSU(2){sub L}xSU(2){sub R}xU(1){sub X}xP{sub LR}. Using the lemmas and performing properly analytic extensions of bulk profiles, we present the sufficient condition for a convergent series of Kaluza-Klein excitations and sum over the series through the residue theorem. The method can also be applied to sum over the infinite series of Kaluza-Klein excitations in a universal extra dimension. Furthermore, we analyze the possible connection between the propagators in five-dimensional full theory and the product of bulk profiles with corresponding propagators of exciting Kaluza-Klein modes in four-dimensional effective theory, and recover some relations presented in the literature for warped and universal extra dimensions, respectively. As an example, we present the correction from new physics to the branching ratio of B{yields}X{sub s{gamma}} to the order O({mu}{sub EW}{sup 2}/{Lambda}{sub KK}{sup 2}) in extension of the standard model with a warped extra dimension and the custodial symmetry, where {Lambda}{sub KK} denotes the energy scale of low-lying Kaluza-Klein excitations and {mu}{sub EW}more » denotes the electroweak energy scale.« less