2018 Physics/Theoretical Colloquium
 
Thursday, September 20th  , 2018
3:45 – 4:45 p.m.
Rosen Auditorium (TA-53, Bldg. 1)
Refreshments at 3:15pm
 
Speaker:   Dr. Amy Nicholson
 
Assistant Professor, Dept. of Physics and Astronomy
University of North Carolina - Chapel Hill
 
“The nucleon axial charge from QCD”
 
Abstract: 
 
The axial charge of the nucleon, g_A, is a fundamental quantity in nuclear physics which governs nuclear beta decay, the nuclear force, and the neutron lifetime, and is extremely well-measured experimentally. However, its calculation directly from the underlying theory of QCD has proven frustratingly difficult, calling into question the potential accuracy of lattice QCD applications to nuclear physics. Here, I present the first lattice QCD calculation of g_A to a precision of 1% with control over all systematics, highlighting new computational strategies which have made this calculation possible. The uncertainty budget is statistics dominated, paving the way for a future sub-percent calculation which may provide important constraints on new physics.