出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We present the first lattice calculation of nucleon matrix elements using four dynamical flavors. We use the Nf =2+1+1 maximally twisted mass formulation. The renormalization is performed non-perturbatively in the RI0-MOM scheme and results are given for the vector and axial vector operators with up to one-derivative. Our calculation of the average momentum of the unpolarized non-singlet parton distribution is presented and compared to our previous results obtained from the Nf = 2 case.
