497 research outputs found
Color screening in flavor QCD at large distances
We study correlation functions of spatially separated static quark-antiquark
pairs in flavor QCD in order to investigate the nature of color screening
at high temperatures. We perform lattice calculations in a wide temperature
range, , using the highly improved
staggered quark (HISQ) action and several lattice spacings to control
discretization effects. We alleviate the UV noise problem through the use of
four dimensional hypercubic (HYP) smearing, which enables the reconstruction of
correlators and determination of screening properties even at low temperatures
and at large distances.Comment: 8 pages, 9 figure
Strong coupling constant from moments of quarkonium correlators revisited
We revisit the previous determination of the strong coupling constant from
moments of quarkonium correlators in (2+1)-flavor QCD. We use previously
calculated moments obtained with Highly Improved Staggered Quark (HISQ) action
for five different quark masses and several lattice spacings. We perform a
careful continuum extrapolation of the moments, and from the comparison of
these to the perturbative result we determine the QCD Lambda parameter,
MeV. This corresponds
to .Comment: 18 pages, 6 figure
Supersphere non-linear sigma model on the lattice
Two-dimensional O(N) non-linear sigma models are exactly solvable theories and have many applications, from statistical mechanics to their use as QCD toy models. We consider a supersymmetric extension, the non-linear sigma model on the supersphere~SN+2m−1|2m≡OSP(N+2m|2m)OSP(N+2m−1|2m) . We briefly describe its renormalization properties and lattice discretization, and present a strategy for numerical simulations together with some preliminary numerical results
Bottomonium suppression in an open quantum system using the quantum trajectories method
We solve the Lindblad equation describing the Brownian motion of a Coulombic
heavy quark-antiquark pair in a strongly coupled quark-gluon plasma using the
highly efficient Monte Carlo wave-function method. The Lindblad equation has
been derived in the framework of pNRQCD and fully accounts for the quantum and
non-Abelian nature of the system. The hydrodynamics of the plasma is
realistically implemented through a 3+1D dissipative hydrodynamics code. We
compute the bottomonium nuclear modification factor and compare with the most
recent LHC data. The computation does not rely on any free parameter, as it
depends on two transport coefficients that have been evaluated independently in
lattice QCD. Our final results, which include late-time feed down of excited
states, agree well with the available data from LHC 5.02 TeV PbPb collisions.Comment: 42 pages, 18 figure
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