English

AKK Update: Improvements from New Theoretical Input and Experimental Data

High Energy Physics - Phenomenology 2010-03-25 v2

Abstract

We perform a number of improvements to the previous AKK extraction of fragmentation functions for π±\pi^\pm, K±K^\pm, p/pˉp/\bar{p}, KS0K_S^0 and Λ/Λˉ\Lambda/\bar{\Lambda} particles at next-to-leading order. Inclusive hadron production measurements from pp(pˉ)pp(\bar{p}) reactions at BRAHMS, CDF, PHENIX and STAR are added to the data sample. We use the charge-sign asymmetry of the produced hadrons in pppp reactions to constrain the valence quark fragmentations. Data from e+ee^+ e^- reactions in regions of smaller xx and lower s\sqrt{s} are added. Hadron mass effects are treated for all observables and, for each particle, the hadron mass used for the description of the e+ee^+ e^- reaction is fitted. The baryons' fitted masses are found to be only around 1% above their true masses, while the values of the mesons' fitted masses have the correct order of magnitude. Large xx resummation is applied in the coefficient functions of the e+ee^+ e^- reactions, and also in the evolution of the fragmentation functions, which in most cases results in a significant reduction of the minimized χ2\chi^2. To further exploit the data, all published normalization errors are incorporated via a correlation matrix.

Keywords

Cite

@article{arxiv.0803.2768,
  title  = {AKK Update: Improvements from New Theoretical Input and Experimental Data},
  author = {S. Albino and B. A. Kniehl and G. Kramer},
  journal= {arXiv preprint arXiv:0803.2768},
  year   = {2010}
}
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