Abstract
We compute the asymmetry in the proton in chiral effective theory, including both nucleon and degrees of freedom, within the relativistic and heavy baryon frameworks. In addition to the distribution at , we compute the corrections to the asymmetry from zero momentum contributions from pion rainbow and bubble diagrams at , which have not been accounted for in previous analyses. We find that the empirical dependence of as well as the integrated asymmetry can be well reproduced in terms of a transverse momentum cutoff parameter.
- Received 20 September 2014
DOI:https://doi.org/10.1103/PhysRevLett.114.122001
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