Free Meson Seminars

The classical nonlinear O(2) sigma model with a chemical potential

by Mr. Debasish Banerjee (TIFR)

Thursday, November 26, 2009 from to (Asia/Kolkata)
at Colaba Campus ( AG-69 )
Description
We study the classical non-linear O(2) sigma model with 
a coupling beta and chemical potential mu on a 2+1 dimensional Euclidean lattice. In the conventional formulation this model suffers from a sign problem at
non-zero chemical potential and hence cannot be 
studied with the Wolff cluster algorithm. However, when formulated in terms of world-line of particles, the sign problem is absent. The world-line formulation can be
studied very efficiently with the ``worm algorithm''. We use this algorithm to uncover the phase diagram in the (beta,mu) plane. In order to do this we develop finite size scaling relations and use them to extract the critical behaviour.
Organised by Saumen Datta