Mon·Sep 17, 2007Monday·September 17, 2007

1. 01*

   Effective field theories for rooted staggered fermions

   Claude Bernard (Washington U.)🇺🇸 · Maarten Golterman (SFSU)🇺🇸 · Yigal Shamir (Tel Aviv)🇮🇱

   We extend the construction of the Symanzik effective action to include rooted staggered fermions, starting from a generalization of the renormalization-group approach to rooted staggered fermions. The Symanzik action, together with the usual construction of a partially quenched chiral effective theory from a local, partially quenched, fundamental theory, can then be used to derive the chiral effective theory. The latter reproduces rooted staggered chiral perturbation theory.

   hep-latPoS(2007)·8 citations
2. 02*

   The Approach to the Thermodynamic Limit in Lattice QCD at \mu\neq0

   K. Splittorff🇩🇰 · J.J.M. Verbaarschot🇺🇸

   The expectation value of the complex phase factor of the fermion determinant is computed to leading order in the $p$-expansion of the chiral Lagrangian. The computation is valid for $\mu <m_{\pi }/2$ and determines the dependence of the sign problem on the volume and on the geometric shape of the volume. In the thermodynamic limit with $L_i\to \infty$ at fixed temperature $1/L_0$, the average phase factor vanishes. In the low temperature limit where $L_i/L_0$ is fixed as $L_i$ becomes large the average phase factor approaches one. The results for a finite volume compare well with lattice results obtained by Allton {\it et al}.. After taking appropriate limits, we reproduce previously derived results for the $ϵ$-regime and for 1-dimensional QCD. The distribution of the phase itself is also computed.

   hep-latPRD(2008)·40 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.