From di-hadron correlations to parton intrinsic transverse momentum in   proton-proton collisions
  Di-hadron correlations in proton-proton collisions at s^1/2 = 200 GeV are interpreted in terms of a fragmentation width and a momentum imbalance. A fragmentation width of 580 +- 50 GeV/c is obtained, and the momentum imbalance gives an `intrinsic' transverse momentum width of partons in the proton of 2.6 +- 0.2 GeV/c. 
G. Fai, P. Levai, G. Papp