Flavor Dependence of Charged Pion Fragmentation Functions
Abstract
We have measured the flavor dependence of multiplicities for pi+ and pi- production in semi-inclusive deep-inelastic scattering (SIDIS) on proton and deuteron targets to explore a possible charge symmetry violation in fragmentation functions. The experiment used an electron beam with energies of 10.2 and 10.6 GeV at Jefferson Lab and the Hall-C spectrometers. The electron kinematics spanned the range 0.3<x<0.6, 2<Q2<5.5 GeV2, and 4<W2<11 GeV2. The pion fractional momentum range was 0.3< z <0.7, and the transverse momentum range was 0<pT<0.25 GeV/c. Assuming factorization at low pT and allowing for isospin breaking, we find that the results can be described by two "favored" and two "un-favored" effective low pT fragmentation functions that are flavor-dependent. However, they converge to a common flavor-independent value at the lowest x or highest W of this experiment.