Hadronic and electromagnetic fragmentation of ultrarelativistic heavy ions at LHC

摘要

Reliable predictions of yields of nuclear fragments produced in electromagnetic dissociation and hadronic fragmentation of ion beams are of great practical importance in analyzing beam losses and interactions with the beam environment at the Large Hadron Collider (LHC) at CERN as well as for estimating radiation effects of galactic cosmic rays on the spacecraft crew and electronic equipment. The model for predicting the fragmentation of relativistic heavy ions is briefly described, and then applied to problems of relevance for LHC. The results are based on the fluka code, which includes electromagnetic dissociation physics and dpmjet-iii as hadronic event generator. We consider the interaction of fully stripped lead ions with nuclei in the energy range from about one hundred MeV to ultrarelativistic energies. The yields of fragments close in the mass and charge to initial ions are calculated. The approach under discussion provides a good overall description of Pb fragmentation data at 30 and $158Aext{ }ext{ }mathrm{GeV}$ as well as recent LHC data for $sqrt{{s}_{mathrm{NN}}}=2.76ext{ }ext{ }mathrm{TeV}$ Pb-Pb interactions. Good agreement with the calculations in the framework of different models is found. This justifies application of the developed simulation technique both at the LHC injection energy of $177Aext{ }ext{ }mathrm{GeV}$ and at its collision energies of 1.38, 1.58, and $2.75Aext{ }ext{ }mathrm{TeV}$, and gives confidence in the results obtained.