124961400
Isospin and temperature dependence of the rearrangement term in Brueckner theory
118506081
Three-body force effect on the properties of nuclear matter under the gap and continuous choices within the BHF approach
We have calculated and compared the three-body force effects on the properties of nuclear matter under the gap and continuous choices for the self-consistent auxiliary potential within the Brueckner-Hartree-Fock approach by adopting the Argonne V-18 and the Bonn B two-body potentials plus a microscopic three-body force (TBF). The TBF provides a strong repulsive effect on the equation of state of nuclear matter at high densities for both the gap and continuous choices. The saturation point turns out to be much closer to the empirical value when the continuous choice is adopted. In addition, the dependence of the calculated symmetry energy upon the choice of the self-consistent auxiliary potential is discussed.
119275256
Effects of the magnetic field on the spallation reaction implemented by BUU coupled with a phase-space coalescence afterburner
Based on the Boltzmann-Uehling-Uhlenbeck (BUU) transport model coupled with a phase-space coalescence afterburner, the spallation reaction p + 197Au at the incident beam energy Ebeam = 800 MeV/nucleon is studied. We find that the number of test particles per nucleon has minor effects on the neutron-to-proton ratio (n/p) of the produced heavier fragments while it affects much their yields. The external strong magnetic field affects the production of heavier fragments more than the n/p of produced fragments. The n/p of free nucleons is greatly affected by the strong magnetic field, especially for the nucleons with lower energies.
15459179
Probing the isospin dependent in-medium nucleon–nucleon cross section by nucleon emissions
The effects of the symmetry potential and the isospin dependent in-medium nucleon-nucleon (NN) cross section on the number of proton(neutron) emissions N-p(N-n) are studied respectively within an isospin-dependent quantum molecular dynamics (IQMD) model. The isospin dependent in-medium NN cross section is found to have a strong influence on Np (Nn) but Np(Nn) is not sensitive to the symmetry potential for the neutron-deficient colliding system at relatively high energies. We propose to make use of the N-p(N-n) as a probe to extract information on the isospin dependent in-medium NN cross section. (C) 2002 Elsevier Science B.V. All rights reserved.
118833038
Transport parameters in neutron stars from in-medium NN cross sections
We present a numerical study of shear viscosity and thermal conductivity of symmetric nuclear matter, pure neutron matter, and beta-stable nuclear matter, in the framework of the Brueckner theory. The calculation of in-medium cross sections and nucleon effective masses is performed with a consistent two- and three-body interaction. The investigation covers a wide baryon density range as needed in the applications to neutron stars. The results for the transport coefficients in beta-stable nuclear matter are used to make preliminary predictions on the damping time scales of nonradial modes in neutron stars.
119110371
Three-body force effect on off-shell mass operator and spectral functions in nuclear matter
Within the framework of the Brueckner theory, the off-shell behaviors of the mass operator $M(k,\omega)=V(k,\omega)+iW(k,\omega)$, i.e., its dependence upon the momentum $k$ and upon the nucleon frequency $\omega$, are investigated by including nuclear three-body force (TBF). The first two terms of the hole-line expansion of the mass operator are taken into account. The TBF effects on their off-shell properties are discussed. A comparison is made between the on-shell and off-shell values of $M_{1}$. The nucleon spectral function and nucleon momentum distribution are also calculated, and the calculation shows that they are hardly affected by the TBF effect at the saturation density. At a high density two times greater than the saturation density, inclusion of the TBF may lead to a visible effect on the spectral function and may enhance the depletion of the hole states.
124568831
Evolution of Vector Boson Distribution
The strong interaction effect on the vector boson distribution is discussed. The three-term expressions of the vector boson distribution inside quark and gluon in leading approximation are given. Our result shows that the strong interaction will effect not only the x-, but also the Q2-dependence for the distributions.
121047651
A More Restrictive Upper Bound for the Bare Pomeron Intercept
By studying the properties of the modified Gribov-Levin-Ryskin evolution equation which incorporates both shadowing and antishadowing effects, the more restrict upper bound is set for the bare pomeron intercept in the case when gluons uniformly distribute within the proton.
123012350
Phenomenological study of Sudakov effects in the pion form factor
The pion electromagnetic form factor with leading and next-to-leading twist corrections is studied in the framework of the pQCD approach. We find that the Sudakov effects provide a weak suppression of the nonperturbative contributions at the experimental accessible energy region. We also find a large twist-3 contribution. Our conclusion is that the prediction of the pion form factor in the pQCD approach is not precise.
118982861
Sudakov form factor in effective field theory
We discuss the Sudakov form factor in the framework of the soft-collinear effective theory. The running of the short distance coefficient function from high to low scale gives the summation of Sudakov logarithms to all orders. Our discussions concentrate on the factorization and derivation of the renormalization group equation from the effective theory point of view. The intuitive interpretation of the renormalization group method is discussed. We compared our method with other resummation approaches in the literatures.
121884540
The Structure Function of Six-Quark Cluster and the EMC Effect
Based upon the experiments on electric form factor for deutron use is made of the valon model to determine the valon distribution functions in a six-quark cluster. By using the QCD evolution equation, the dependence of the structure function of a six-quark cluster is obtained. The EMC effect is discussed and it is pointed out that the distortion of the nucleon structure function in nuclei may be ascribed to the contributions from the six-quark cluster(for ) and the meson cloud(for ).