Nucleon Tensor Charges in the Chiral Quark–soliton Model

We investigate the singlet g (0) T and isovector g (3) T tensor charges of the nucleon, which are deeply related to the first moment of the leading twist transversity quark distribution h1(x), in the chiral quark-soliton model. With rotational O(1/Nc) corrections taken into account, we obtain g (0) T = 0.69 and g (3) T = 1.45 at a low normalization poin of several hundreds MeV. Within the same approximation and parameters the model yields g (0) A = 0.36, g (3) A = 1.21 for axial charges and correct octet–decuplet mass splitting. We show how the chiral quark-soliton model interpolates between the nonrelativistic quark model and the Skyrme model. The nucleon tensor charges are defined as a nucleon forward matrix element [1] 〈N |ψ̄fσμνψf |N〉 = g f T ŪσμνU, (1) where U(p) is a standard Dirac spinor and σμν = i 2 [γμ, γν] in notation of Bjorken and Drell [2]. The tensor charges, as shown by Jaffe and Ji [1], are related to the first moment of the transversity quark distribution h1(x):