A Linear Sigma Model with Three Flavors and Vector and Axial-Vector Mesons

We outline the extension of the globally chirally invariant Nf = 2 linear sigma model with vector and axial-vector degrees of freedom to Nf=3. We present preliminary results concerning the scalar meson masses.Comment: Prepared for the Proceedings of the 11th International Workshop on Meson Production, Properties and Interaction (MESON 2010), in Krakow, Poland, 10-15 June 2010. Three page

Flat band ferromagnetism without connectivity conditions in the flat band

It is known that a system which exhibits a half filled lowest flat band and the localized one-particle Wannier states on the flat band satisfy the connectivity conditions, is always ferromagnetic. Without the connectivity conditions on the flat band, the system is non-magnetic. We show that this is not always true. The reason is connected to a peculiar behavior of the band situated just above the flat band.Comment: 15 pages, 4 figure

Effects of (axial)vector mesons on the chiral phase transition: initial results

We investigate the effects of (axial)vector mesons on the chiral phase transition in the framework of an SU(3), (axial)vector meson extended linear sigma model with additional constituent quarks and Polyakov loops. We determine the parameters of the Lagrangian at zero temperature in a hybrid approach, where we treat the mesons at tree-level, while the constituent quarks at 1-loop level. We assume two nonzero scalar condensates and together with the Polyakov-loop variables we determine their temperature dependence according to the 1-loop level field equations.Comment: 4 pages, 2 figures, MESON2014 - the 13^{th} International Workshop on Meson Production, Properties and Interactio

Random walk of second class particles in product shock measures

We consider shock measures in a class of conserving stochastic particle systems on Z. These shock measures have a product structure with a step-like density profile and include a second class particle at the shock position. We show for the asymmetric simple exclusion process, for the exponential bricklayers' process, and for a generalized zero range process, that under certain conditions these shocks, and therefore the second class particles, perform a simple random walk. Some previous results, including random walks of product shock measures and stationary shock measures seen from a second class particle, are direct consequences of our more general theorem. Multiple shocks can also be handled easily in this framework. Similar shock structure is also found in a nonconserving model, the branching coalescing random walk, where the role of the second class particle is played by the rightmost (or leftmost) particle.Comment: Minor changes after referees' comment