2009/03/17 by Silas R. Beane, William Detmold, Thomas C. Luu +8 · 78 citations
Physics and Astronomy · #Anisotropy #Baryon #Fermion #Gauge theory #Hadron #High-Energy Particle Collisions Research #Lattice (music) #Lattice gauge theory #Mathematical physics #Nucleon #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #hep-lat
paper · pdf · doi:10.1103/physrevd.79.114502
published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 79(11) (American Physical Society)
arxiv created 2009/03/17 · openalex publication_date 2009/06/16 · arxiv updated 2010/04/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present the results of high-statistics calculations of correlation functions generated with single-baryon interpolating operators on an ensemble of dynamical anisotropic gauge-field configurations generated by the Hadron Spectrum Collaboration using a tadpole-improved clover fermion action and Symanzik-improved gauge action. A total of 292, 500 sets of measurements are made using 1194 gauge configurations of size 203\ifmmode×\else\texttimes\fi128 with an anisotropy parameter \ensuremathξ=bs/bt=3.5, a spatial lattice spacing of bs=0.1227\ifmmode±\else\textpm\fi0.0008 fm, and pion mass of M_\ensuremathπ\ensuremath∼390 MeV. Ground state baryon masses are extracted with fully quantified uncertainties that are at or below the \ensuremath∼0.2%-level in lattice units. The lowest-lying negative-parity states are also extracted albeit with a somewhat lower level of precision. In the case of the nucleon, this negative-parity state is above the N\ensuremathπ threshold and, therefore, the isospin-(1)/(2) \ensuremathπN s-wave scattering phase-shift can be extracted using L"uscher's method. The disconnected contributions to this process are included indirectly in the gauge-field configurations and do not require additional calculations. The signal-to-noise ratio in the various correlation functions is explored and is found to degrade exponentially faster than naive expectations on many time slices. This is due to backward propagating states arising from the antiperiodic boundary conditions imposed on the quark propagators in the time direction. We explore how best to distribute computational resources between configuration generation and propagator measurements in order to optimize the extraction of single baryon observables.