Tensor Charge of the Nucleon from QCD Sum Rules

摘要

The nucleon''s tensor charges(isovector g_(T)^(v)=δu-δd and isoscalar g_(T)^(s)=δu+δd)are calculated using the QCD(quantum chromodynamics)sum rules in the presence of an external tensor field.By combining the mass sum rule of nucleon,we derive a simplified form for proton tensor charges,which gives g_(T)^(v)=1.27 and g_(T)^(s)=1.31,or δu=1.29 and δd=0.02 at the scale of nucleon mass,with an uncertainty about 20%.