Tue·Oct 30, 2007Tuesday·October 30, 2007

1. 01*

   Quarkonium correlators at finite temperature and potential models

   Agnes Mocsy🇺🇸 · Peter Petreczky🇺🇸

   We discuss the calculations of quarkonium spectral functions in potential models and their implications for the interpretation of the lattice data on quarkonium correlators. In particular, we find that melting of different quarkonium states does not lead to significant change in the Euclidean time correlators. The large change of the quarkonium correlators above deconfinement observed in the scalar and axial-vector channels appears to be due to the zero mode contribution.

   hep-latPoS(2007)·11 citations
2. 02*

   The Static Approximation to B Meson Mixing using Light Domain-Wall Fermions: Perturbative Renormalization and Ground State Degeneracies

   Norman H. Christ🇺🇸 · Thomas T. Dumitrescu🇺🇸 · Taku Izubuchi🇺🇸 · Oleg Loktik🇺🇸

   We discuss the theoretical input into the current RBC-UKQCD calculation of $f_{B_{d,s}}$ and $B_{B_{d,s}}$ using a smeared static heavy quark propagator, light domain-wall quarks and the Iwasaki gauge action. We present the complete one-loop, mean-field improved matching of heavy-light current and four-fermion lattice operators onto the static continuum theory renormalized in $\overline{\text{MS}}$(NDR). The large degeneracies present in a static calculation are addressed, and a method for extracting $f_B$ and $B_B$ using only box sources is described; implications for future calculations are discussed.

   hep-latPoS(2007)·13 citations
3. 03*

   Status of 2+1 flavor, 32^3x64 domain wall fermion simulations

   Chulwoo Jung · for RBC · UKQCD collaborations

   We describe details of 1/a ~ 2.2Gev, L ~ 3 fm dynamical domain wall fermion simulations which will allow us to do a more systematic continuum extrapolation in combination with existing simu- lations. Details of the simulations such as algorithm choices and machine performance, as well as results of basic measurements are presented. These configurations are presently being generated on the QCDOC machine at Edinburgh and the DOE QCDOC machine at Brookhaven as part of a joint project with LHPC.

   hep-latPoS(2007)·4 citations
4. 04*

   Towards Weyl fermions on the lattice without artefacts

   Peter Hasenfratz🇨🇭 · Reto von Allmen🇨🇭

   In spite of the breakthrough in non-perturbative chiral gauge theories during the last decade, the present formulation has stubborn artefacts. Independently of the fermion representation one is confronted with unwanted CP violation and infinitely many undetermined weight factors. Renormalization group identifies the culprit. We demonstrate the procedure on Weyl fermions in a real representation.

   hep-latJHEP(2008)·20 citations
5. 05*

   Remarks on left-handed lattice fermions

   Christof Gattringer🇦🇹 · Markus Pak🇦🇹

   We study whether applying lattice projectors on a vector-like Ginsparg-Wilson Dirac operator is the only way to construct left-handed lattice fermions. Using RG transformations we derive an equation for the generating functional on the lattice, obtained by blocking from the continuum. We analyze how symmetries of the continuum theory manifest themselves in this lattice generating functional and how anomalies emerge. The formalism is applied to left-handed continuum fermions and we derive two equations that characterize the corresponding lattice symmetries. To analyze possible solutions, we directly block a parameterized action for free continuum fermions to obtain the corresponding lattice action. Subsequently we study parameter values where the continuum action corresponds to left-handed fermions.

   hep-latPoS(2007)·3 citations
6. 06*

   Deflation acceleration of lattice QCD simulations

   Martin Lüscher🇨🇭

   Close to the chiral limit, many calculations in numerical lattice QCD can potentially be accelerated using low-mode deflation techniques. In this paper it is shown that the recently introduced domain-decomposed deflation subspaces can be propagated along the field trajectories generated by the Hybrid Monte Carlo (HMC) algorithm with a modest effort. The quark forces that drive the simulation may then be computed using a deflation-accelerated solver for the lattice Dirac equation. As a consequence, the computer time required for the simulations is significantly reduced and an improved scaling behaviour of the simulation algorithm with respect to the quark mass is achieved.

   hep-latJHEP(2007)·136 citations
7. 07*

   Tests of the lattice index theorem

   Gerald Jordan🇦🇹 · Roman Hoellwieser🇦🇹 · Manfried Faber🇦🇹 · Urs M. Heller🇺🇸

   We investigate the lattice index theorem and the localization of the zero-modes for thick classical center vortices. For non-orientable spherical vortices, the index of the overlap Dirac operator differs from the topological charge although the traces of the plaquettes deviate only by a maximum of 1.5% from trivial plaquettes. This may be related to the fact that even in Landau gauge some links of these configuration are close to the non-trivial center elements.

   hep-latPRD(2008)·31 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.