Speaker
Description
We study the finite temperature equation of state by using an effective lagrangian in which a dilaton field reproduces the breaking of scale symmetry in QCD.
We start by extending a previous investigation in the pure gauge sector $SU(3)_c$ [1], where the dynamics of the gluon condensate, expressed in terms of a dilaton lagrangian, is dominated below the critical phase transition temperature by the dilaton field, while at greater temperatures the condensate evaporates in the form of quasi-free gluons.
In this context, we study the role of the thermal fluctuations of the dilaton field, through the technique proposed in Ref.s [2,3]. This approach enables the reproduction of the lattice QCD results for the thermodynamic quantities such as pressure and energy [4].
Moreover, we have extended the study to the equation of state with additional degrees of freedom, namely the $\sigma$, $\pi$, $\omega$ and $\rho$ mesons and nucleons, at finite chemical potential by means of an effective lagrangian which incorporates broken scale in addition to explicitly broken chiral symmetry [5,6].
Beyond the mean-field approximation, we study the relevance of the thermal fluctuations of the scalar glueball, other than the contribution of the $\sigma$ and $\pi$ meson fields, and investigate the thermodynamic nature of the phase transition.
References
[1] A. Drago, M. Gibilisco, and C. Ratti, Nuclear Physics A, 742, 165, 2004.
[2] G. W. Carter, O. Scavenius, I. N. Mishustin, and P. J. Ellis, Phys. Rev. C, 61, 045206, 2000.
[3] A. M´ocsy, I. N. Mishustin, and P. J. Ellis, Phys. Rev. C, 70, 015204, 2004.
[4] S. Bors´anyi, G. Endr˝odi, Z. Fodor, S. D. Katz, and K. K. Szab´o, Journal of High Energy Physics, 2012,56, 2012.
[5] G. Carter, P. Ellis, and S. Rudaz, Nuclear Physics A, 618, 317, 1997.
[6] L. Bonanno and A. Drago, Phys. Rev. C, 79, 045801, 2009.
| Category | Theory |
|---|
