Journalartikel

Jahr der Veröffentlichung: 2000

Zeitschrift: Physical Review D

Bandnummer: 62

Heftnummer: 3

ISSN: 2470-0010

eISSN: 2470-0029

Open Access Status: Green

DOI Link: https://doi.org/10.1103/PhysRevD.62.036012

Verlag: American Physical Society

Abstract: 
Applying a microscopically motivated semiclassical Langevin description of the linear sigma model we investigate for various different scenarios the stochastic evolution of a disoriented chiral condensate (DCC) in a rapidly expanding system. Some particular emphasis is put on the numerical realization of colored noise in order to treat the underlying dissipative and non-Markovian stochastic equations of motion. A comparison with an approximate Markovian (i.e., instantaneous) treatment of dissipation and noise will be made in order to identify the possible influence of memory effects in the evolution of the chiral order parameter. Assuming a standard Rayleigh cooling term to simulate a D-dimensional scaling expansion we present the probability distribution in the low momentum pion number stemming from the relaxing zero mode component of the chiral field. The best DCC signal is expected for initial conditions centered around [sigma] approximate to 0 as would be the case of effective light ''pions" close to the phase transition. By choosing appropriate idealized global parameters for the expansion our findings show that an experimentally feasible DCC, if it does exist in nature, has to be a rare event with some finite probability following a nontrivial and non-Poissonian distribution on an event by event basis. DCCs might then be identified experimentally by inspecting higher order factorial cumulants theta(m) (m greater than or equal to 3) in the sampled distribution.

Harvard-Zitierstil: Xu, Z. and Greiner, C. (2000) Stochastic treatment of disoriented chiral condensates within a Langevin description, Physical Review D, 62(3), Article 036012. https://doi.org/10.1103/PhysRevD.62.036012

APA-Zitierstil: Xu, Z., & Greiner, C. (2000). Stochastic treatment of disoriented chiral condensates within a Langevin description. Physical Review D. 62(3), Article 036012. https://doi.org/10.1103/PhysRevD.62.036012