QCD analysis of Lambda hyperon production in DIS target-fragmentation region
- 86 Downloads
We consider Lambda-hyperon production in the target-fragmentation region of semi-inclusive deep-inelastic scattering within the framework of fracture functions. We present a first attempt to determine the flavour and energy dependences of these non-perturbative distributions through a simultaneous QCD-based fit to available neutral- and charged-current semi-inclusive-DIS cross sections. Predictions based on the resulting nucleon-to-Lambda fracture functions are in good agreement with data and observables not included in the regression. The successful prediction of the Q 2 dependence of the Lambda multiplicity notably represents the first validation of the perturbative framework implied by fracture functions.
KeywordsTransverse Momentum Parton Distribution Fragmentation Function Fracture Function Spectator System
We gratefully acknowledge M. Stratmann and S. Albino for providing us with their fragmentation-function routines. We especially acknowledge D. Naumov for interesting discussions related to backgrounds in Lambda production in DIS and for providing us the neutrino flux parametrisations. We wish to thank the organizers of the Workshop “Strangeness polarization in semi-inclusive and exclusive Lambda production” held in ECT*, Trento, in October 2008 and all the participants for stimulating discussions on this topic. We finally thank Laurent Favart, Dmitry Naumov, Jean-René Cudell and Luca Trentadue for a critical reading of the manuscript prior to submission.