Christian Hoelbling

Is there still any T c mystery in lattice QCD? Results with physical masses in the continuum limit III

The present paper concludes our investigations on the QCD cross-over transition temperatures with 2+1 staggered flavours and one-link stout improvement. We extend our previous two studies [Phys. Lett. B643 (2006) 46, JHEP 0906:088 (2009)] by choosing even finer lattices (Nt = 16) and we work again with physical quark masses. The new results on this broad cross-over are in complete agreement with our earlier ones. We compare our findings with the published results of the hotQCD collaboration. All these results are confronted with the predictions of the Hadron Resonance Gas model and Chiral Perturbation Theory for temperatures below the transition region. Our results can be reproduced by using the physical spectrum in these analytic calculations. The findings of the hotQCD collaboration can be recovered by using a distorted spectrum which takes into account lattice discretization artifacts and heavier than physical quark masses. This analysis provides a simple explanation for the observed discrepancy in the transition temperatures between our and the hotQCD collaborations.

K{sup 0}-K{sup 0} mixing beyond the standard model and CP-violating electroweak penguins in quenched QCD with exact chiral symmetry

We present results for the

Rationale for UV-filtered clover fermions

\ensuremath{\Delta}S=2

Staggered eigenvalue mimicry

matrix elements which are required to study neutral kaon mixing in the standard model (SM) and beyond . We also provide leading chiral order results for the matrix elements of the electroweak penguin operators which give the dominant

Scaling tests with dynamical overlap and rooted staggered fermions

\ensuremath{\Delta}I=3/2

Precision study of the SU(3) topological susceptibility in the continuum

contribution to direct

Staggered versus overlap fermions: A Study in the Schwinger model with N(f)=0, 1, 2

CP

Diquark correlations in baryons on the lattice with overlap quarks

violation in

Filtered overlap: speedup, locality, kernel non-normality and ZA ≃ 1

K\ensuremath{\rightarrow}\ensuremath{\pi}\ensuremath{\pi}

B~K from Quenched QCD with Exact Chiral Symmetry

decays. Our calculations were performed with Neuberger fermions on two sets of quenched Wilson gauge configurations at inverse lattice spacings of approximately 2.2 GeV and 1.5 GeV. All renormalizations were implemented nonperturbatively in the regularization-independent/momentum (RI/MOM) scheme, where we accounted for subleading operator product expansion corrections and discretization errors. We find ratios of non-SM to SM matrix elements which are roughly twice as large as in the only other dedicated lattice study of these amplitudes. On the other hand, our results for the electroweak penguin matrix elements are in good agreement with two recent domain-wall fermion calculations. As a by-product of our study, we determine the strange quark mass. Our main results are summarized and discussed in Sec. VII. Within our statistics, we find no evidence for scaling violations.