Hadronization in semi-inclusive deep-inelastic scattering on nuclei

Abstract

A series of semi-inclusive deep-inelastic scattering measurements on deuterium, helium, neon, krypton, and xenon targets has been performed in order to study hadronization. The data were collected with the HERMES detector at the DESY laboratory using a 27.6 GeV positron or electron beam. Hadron multiplicities on nucleus A relative to those on the deuteron, R h A , are presented for various hadrons (π + , π − , π 0 , K + , K − , p, andp) as a function of the virtual-photon energy ν, the fraction z of this energy transferred to the hadron, the photon virtuality Q 2 , and the hadron transverse momentum squared p 2 t . The data reveal * Corresponding author. E-mail address: james.stewart@desy.de (J. Stewart). B 780 (2007) A on ν and z can largely be described as a dependence on a single variable L c , which is a combination of ν and z. The dependence on L c suggests in which kinematic conditions partonic and hadronic mechanisms may be dominant. The behaviour of R π A at large p 2 t constitutes tentative evidence for a partonic energy-loss mechanism. The A-dependence of R h A is investigated as a function of ν, z, and of L c . It approximately follows an A α form with α ≈ 0.5-0.6. HERMES Collaboration / Nuclear Physics

Incorporating space-time within medium-modified jet-event generators

“…In the medium-modified calculation, we have chosen a medium of length 4 fm witĥ q = 0.2 GeV 2 /fm. This is comparable to the measured ratio 014909-8 of the yields of leading hadrons observed in the case of DIS on a large nucleus to that in a proton, as seen in the HERMES experiment [47]. The parameters used are somewhat close to the case of the krypton nucleus [32].…”

Monte Carlo simulations of hadronic fragmentation functions using the Nambu–Jona-Lasinio–jet model

“…It is reasonable to expect that in the near future an understanding of the fragmentation functions will be attained, which is as precise as the present knowledge on quark distribution functions. Very interesting prospects for the study of fragmentation processes were opened by the HERMES [13] and JLab [14][15][16][17] semi-inclusive measurements on nuclear targets, which will be followed up by the planned Electron-Ion Collider [18,19].…”

Effects of final-state interactions in neutrino-nucleus interactions

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