arXiv subjects

Xiangdong Li C. M. Shakin

Publications and source records attributed to Xiangdong Li C. M. Shakin.

3 recordsLinked to original sources

arXiv2005

Vector-Isovector Excitations at Finite Density and Temperature and the Validity of Brown-Rho Scaling

Recent work reported at the Quark Matter Conference 2005 has led to the suggestion that Brown-Rho scaling is ruled out by the NA60 data. (Brown-Rho scaling describes the reduction of hadronic masses in matter and at finite temperature.) In the present work we argue that the interpretation of the experimental data presented at the Quark Matter Conference is not correct and that Brown-Rho scaling is valid. To make this argument we discuss the evolution in time of the excited hadronic system and suggest that the system is deconfined at the earliest times and becomes confined when the density and temperature decrease as the system evolves. Thus, we suggest that we see both the properties of the deconfined and confined systems in the experimental data. In our interpretation, Brown-Rho scaling refers to the later times of the collision, when the system is in the confined phase.

nucl-th↗

arXiv2004

Description of Gluon Propagation in the Presence of an A^2 Condensate

There is a good deal of current interest in the condensate A^2 which has been seen to play an important role in calculations which make use of the operator product expansion. That development has led to the publication of a large number of papers which discuss how that condensate could play a role in a gauge-invariant formulation. In the present work we consider gluon propagation in the presence of such a condensate which we assume to be present in the vacuum. We show that the gluon propagator has no on-mass-shell pole and, therefore, a gluon cannot propagate over extended distances. That is, the gluon is a nonpropagating mode in the gluon condensate. In the present work we discuss the properties of both the Euclidean-space and Minkowski-space gluon propagator. In the case of the Euclidean-space propagator we can make contact with the results of QCD lattice calculations of the propagator in the Landau gauge. With an appropriate choice of normalization constants, we present a unified representation of the gluon propagator that describes both the Minkowski-space and Euclidean-space dynamics in which the A^2 condensate plays an important role.

hep-ph↗

arXiv2004

The Gluon Propagator in Minkowski and Euclidean Space: Role of an A^2 Condensate

In a recent work we described the form taken by the Minkowski-space gluon propagator in the presence of an A^2 condensate. This condensate has been seen to play an important role in calculations which make use of the operator product expansion. The latter work has led to the publication of a large number of papers which discuss how the A^2 condensate could play a role in a gauge-invariant formulation. In the present work we discuss the properties of both the Euclidean-space and Minkowski-space gluon propagator. In the case of the Euclidean-space propagator we can make contact with the results of QCD lattice calculations of the propagator in the Landau gauge. With an appropriate choice of normalization constants, we present a unified representation of the gluon propagator that describes both the Minkowski-space and Euclidean-space dynamics in which the A^2 condensate plays an important role.

hep-ph↗