82,792 research outputs found
Coupling of pion condensate, chiral condensate and Polyakov loop in an extended NJL model
The Nambu Jona-Lasinio model with a Polyakov loop is extended to finite
isospin chemical potential case, which is characterized by simultaneous
coupling of pion condensate, chiral condensate and Polyakov loop. The pion
condensate, chiral condensate and the Polyakov loop as functions of temperature
and isospin chemical potential are investigated by minimizing the thermodynamic
potential of the system. The resulting phase diagram is studied
with emphasis on the critical point and Polyakov loop dynamics. The tricritical
point for the pion superfluidity phase transition is confirmed and the phase
transition for isospin symmetry restoration in high isospin chemical potential
region perfectly coincides with the crossover phase transition for Polyakov
loop. These results are in agreement with the Lattice QCD data.Comment: 15pages, 8 figure
Landau meets Newton: time translation symmetry breaking in classical mechanics
Every classical Newtonian mechanical system can be equipped with a
nonstandard Hamiltonian structure, in which the Hamiltonian is the square of
the canonical Hamiltonian up to a constant shift, and the Poisson bracket is
nonlinear. In such a formalism, time translation symmetry can be spontaneously
broken, provided the potential function becomes negative. A nice analogy
between time translation symmetry breaking and the Landau theory of second
order phase transitions is established, together with several example cases
illustrating time translation breaking ground states. In particular, the
CDM model of FRW cosmology is reformulated as the time translation
symmetry breaking ground states.Comment: 10 pages, 1 figure. V2: minor correction
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