arXiv subjects

Amy N. Nicholson

Publications and source records attributed to Amy N. Nicholson.

20 records · Page 2Linked to original sources

arXiv2010

Lattice calculation for unitary fermions in a finite box

A fundamental constant in systems of unitary fermions is the so-called Bertsch parameter, the ratio of the ground state energy for spin paired unitary fermions to that for free fermions at the same density. I discuss how we computed this parameter as well as the pairing gap using a recently developed lattice construction for unitary fermions, by measuring correlation functions for up to 38 fermions in a finite box. Our calculation illustrates interesting issues facing the study of many-body states on the lattice, which may eventually be confronted in QCD calculations as well.

hep-lat↗

arXiv2010

Reducing Baryon Noise in Lattice QCD Through Partial Quenching

The study of nuclear physics using lattice QCD is hindered by an exponentially large signal-to-noise problem which is conventionally alleviated by raising the quark masses to unphysically high values. We propose a novel form of partial quenching for calculations involving nucleons in which the sea quark masses are taken to be smaller than the valence quark masses. It is shown that lowering the sea quark masses toward their physical values actually improves signal-to-noise. An optimized approach to the physical point in the (m_s, m_v) plane is proposed, with a full analysis of the cost benefit. Improvements in computing time of ~ 10^(2(A-1)), where A is the number of nucleons in the system, are shown to be possible.

hep-lat↗