11 research outputs found
Meson screening masses from lattice QCD with two light and the strange quark
We present results for screening masses of mesons built from light and
strange quarks in the temperature range of approximately between 140 MeV to 800
MeV. The lattice computations were performed with 2+1 dynamical light and
strange flavors of improved (p4) staggered fermions along a line of constant
physics defined by a pion mass of about 220 MeV and a kaon mass of 500 MeV. The
lattices had temporal extents Nt = 4, 6 and 8 and aspect ratios of Ns / Nt \geq
4. At least up to a temperature of 140 MeV the pseudo-scalar screening mass
remains almost equal to the corresponding zero temperature pseudo-scalar (pole)
mass. At temperatures around 3Tc (Tc being the transition temperature) the
continuum extrapolated pseudo-scalar screening mass approaches very close to
the free continuum result of 2 \pi T from below. On the other hand, at high
temperatures the vector screening mass turns out to be larger than the free
continuum value of 2 \pi T. The pseudo-scalar and the vector screening masses
do not become degenerate even for a temperature as high as 4Tc. Using these
mesonic spatial correlation functions we have also investigated the restoration
of chiral symmetry and the effective restoration of the axial symmetry. We have
found that the vector and the axial-vector screening correlators become
degenerate, indicating chiral symmetry restoration, at a temperature which is
consistent with the QCD transition temperature obtained in previous studies. On
the other hand, the pseudo-scalar and the scalar screening correlators become
degenerate only at temperatures larger than 1.3Tc, indicating that the
effective restoration of the axial symmetry takes place at a temperature larger
than the QCD transition temperature.Comment: Published versio
Genetic stability of attenuated mengovirus vectors with duplicate primary cleavage sequences
Fluid-dynamical description of the gap fluctuations of two trapped fermion species
We apply a recent generalisation of the fluid-dynamical scheme
developed for two trapped fermion species with pairing interactions
to examine the fluctuations of the gap density coupled to the
particle transition density at low energy. The dynamical scheme
satisfies Kohn's theorem for both the particle density and the
pairing gap. We analyse the form of the gap fluctuations in a
spherical trap in terms of their multipolarity and the interaction
strength, and find that coupling to the particle density produces
considerable stiffness of the gap transition density together with
compression towards the centre of the trap