Eur. Phys. J. C 22, 451-461 (2001)
DOI: 10.1007/s100520100836
Diquark condensation in dense adjoint matter
S. Hands1, I. Montvay2, L. Scorzato1 and J. Skullerud21 Department of Physics, University of Wales Swansea, Singleton Park, Swansea SA2 8PP, UK
2 Theory Division, DESY, Notkestraße 85, 22603 Hamburg, Germany
(Received: 28 September 2001 / Published online: 23 November 2001 - © Springer-Verlag / Società Italiana di Fisica 2001 )
Abstract
We study SU(2) lattice gauge theory at non-zero chemical potential
with one staggered quark flavor in the adjoint representation. In
this model the fermion determinant, although real, can be both
positive and negative. We have performed numerical simulations using
both hybrid Monte Carlo and two-step multibosonic algorithms, the
latter being capable of exploring sectors with either determinant
sign. We find that the positive determinant sector behaves like a
two-flavor theory, with the chiral condensate rotating into a
two-flavor diquark condensate for
, implying a superfluid
ground state. Good agreement is found with analytical predictions made
using chiral perturbation theory. In the `full' model there is no sign
of either onset of baryon density or diquark condensation for the
range of chemical potentials we have considered. The impact of the
sign problem has prevented us from exploring the true onset transition
and the mode of diquark condensation, if any, for this model.
© Società Italiana di Fisica, Springer-Verlag 2001
