121299160
Properties of the FLIC overlap quark propagator
FLIC overlap fermions are a type of smeared link action in which the FLIC (Fat Link Irrelevant Clover) fermion action is used as the overlap kernel instead of the standard Wilson fermion action. We study the (quenched) quark propagator in momentum space using the FLIC overlap fermion action, and compare it to that of the Wilson overlap. We find that the two actions have different discretization errors which decrease with the quark mass. We also examine the FLIC overlap quark propagator within the dynamical kernel approximation, where the FLIC Overlap action is used for the valence quarks and the FLIC fermion action is used for the quark sea. Our results indicate that the quark propagator is relatively insensitive to the fermion sea.
119064653
Scaling of nonperturbative renormalization of composite operators with overlap fermions
Copyright © 2005. All rights reserved. Printed in U.S.A. Submitted to Cornell University’s online archive www.arXiv.org in 2005 by Jianbo Zhang. Post-print sourced from www.arxiv.org.
116031505
Impact of stout-link smearing in lattice fermion actions
The impact of stout-link smearing in lattice fermion actions is examined through the consideration of the mass and renormalization functions of the overlap quark propagator over a variety of smeared configurations. Up to six sweeps of stout-link sme aring are investigated. For heavy quark masses, the quark propagator is strongly affected by the smearing procedure. For moderate masses, the effect appears to be negligible. A small effect i s seen for light quark masses, where dynamical mass generation is suppressed through the smearing procedure.
119433952
Scaling behavior of the overlap quark propagator in the Landau gauge
The properties of the momentum space quark propagator in Landau gauge are examined for the overlap quark action in quenched lattice QCD. Numerical calculations are done on three lattices with different lattice spacings and similar physical volumes to explore the approach of the quark propagator toward the continuum limit. We have calculated the nonperturbative momentum-dependent wave-function renormalization function $Z({\ensuremath{\zeta}}^{2};p)$ and the nonperturbative mass function $M(p)$ for a variety of bare quark masses and perform an extrapolation to the chiral limit. We find the behavior of $Z({\ensuremath{\zeta}}^{2};p)$ and $M(p)$ are in reasonable agreement between the two finer lattices in the chiral limit, however the data suggest that an even finer lattice is desirable. The large momentum behavior is examined to determine the quark condensate.
119452670
Pion decay constant, ZA and chiral log from overlap fermions
Abstract We report our calculation of the pion decay constant f π , the axial renormalization constant Z A , and the quenched chiral logarithms from the overlap fermions. The calculation is done on a quenched 20 4 lattice at a = 0.148 fm using tree level tadpole improved gauge action. The smallest pion mass we reach is about 280 MeV. The lattice size is about 4 times the Compton wavelength of the lowest mass pion.
858386
Chiral symmetry, quark mass, and scaling of the overlap fermions
The chiral symmetry relation and scaling of the overlap fermions are studied numerically on the quenched lattices at 3 couplings with about the same physical volume. We find that the generalized Gell-Mann-Oakes-Renner relation is satisfied to better than 1% down to the smallest quark mass at m(0)a = 0.006. We also obtain the quark mass from the PCAC relation and the pseudoscalar masses. The renormalization group invariant quark mass is shown to be fairly independent of scale. The pi and rho masses at a fixed m(pi)/m(rho) ratio indicate small O(a(2)) corrections. It is found that the critical slowing down sets in abruptly at a very small quark mass close to those of the physical u and d quarks.
118385962
Possibility of $\Sigma_{c}(2800)$ and $\Lambda_{c}(2940)^{+}$ as $S$-wave $D^{(*)}N$ molecular states
In this talk, we give a brief review of our work studying the possibility of $\Sigma_{c}(2800)$ and $\Lambda_{c}(2940)^{+}$ as $S$-wave $D^{(*)}N$ molecular states from QCD sum rules.
118608841
Preheating in bubble collisions
In a landscape with metastable minima, the bubbles will inevitably nucleate. We show that when the bubbles collide, due to the dramatic oscillation of the field at the collision region, the energy deposited in the bubble walls can be efficiently released by the explosive production of the particles. In this sense, the collision of bubbles is actually highly inelastic. The cosmological implications of this result are discussed.
118496902
Note on thermodynamics method of black hole/CFT correspondence
A bstractIn the paper we further refine the thermodynamics method of black hole/CFT correspondence. We show that one can derive the central charges of different holographic pictures directly from the entropy product S+S− if it is mass-independent, for a black hole in the Einstein gravity or the gravity without diffeomorphism anomaly. For a general black hole in the Einstein gravity that admits holographic descriptions, we show that the thermodynamics method and asymptotic symmetry group (ASG) analysis can always give consistent results in the extreme limit. Furthermore, we discuss the relation between black hole thermodynamics and the hidden conformal symmetry. We show that the condition T+A+ = T−A−, with A± being the outer and inner horizon areas, is the necessary, but not sufficient, condition for a black hole to have the hidden conformal symmetry. In particular, for the Einstein(-Maxwell) gravity T+A+ = T−A− is just the condition T+S+ = T−S−, with S± being the outer and inner horizon entropies, which is the condition for the entropy product S+S− being mass-dependent. When there exists the hidden conformal symmetry in the low-frequency scattering off the generic non-extremal black hole, it always leads to the same temperatures of dual CFT as the ones got from the thermodynamics method.
118804860
Signature of large extra dimensions from Z boson pair production at the CERN Large Hadron Collider
We study the Z boson pair production mediated by the Kaluza-Klein (KK) graviton in large extra dimensions (LED) at the CERN Large Hadron Collider (LHC). We use the partial wave unitarity to discuss the constraints on the process energy scale in order to give a self-consistent calculation. We find that the LED contributions can enhance the Z boson pair production cross sections significantly when the fundamental scale M{sub S} of the large extra dimensions is up to several TeV. We also show that the kinematic distributions of the LED signals are greatly different from the standard model ones and the LHC can probe the M{sub S} values up to 4.3-5.6 TeV at 3{sigma} level depending on the number of the extra dimensions.
118483519
Hydrodynamics with conserved current via AdS/CFT correspondence in the Maxwell-Gauss-Bonnet gravity
Using the AdS/CFT correspondence, we study the hydrodynamics with conserved current from the dual Maxwell-Gauss-Bonnet gravity. After constructing the perturbative solution to the first order based on the boosted black brane solution in the bulk Maxwell-Gauss-Bonnet gravity, we extract the stress tensor and conserved current of the dual conformal fluid on its boundary, and also find the effect of Gauss-Bonnet term on the dual conformal fluid. Our results show that the Gauss-Bonnet term can affect the parameters such as the shear viscosity $\eta$, entropy density $s$, thermal conductivity $\kappa$ and electrical conductivity $\sigma$. However, it does not affect the so-called Wiedemann-Franz law which relates $\kappa$ to $\sigma$, while it affects the ratio $\eta/s$. In addition, another interesting result is that the $\eta/s$ can also be affected by the bulk Maxwell field in our case, which is consistent with some previous results predicted through the Kubo formula. Moreover, the anomalous magnetic and vortical effects by adding the Chern-Simons term are also considered in our case in the Maxwell-Gauss-Bonnet gravity.