Eur. Phys. J. C 21, 563-566 (2001)
DOI: 10.1007/s100520100739

Photoproduction of top quarks in peripheral heavy ion collisions

S.R. Klein¹, J. Nystrand¹ and R. Vogt<sup>1, 2

1</sup>  Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
²  Physics Department, University of California, Davis, CA 95616, USA

(Received: 18 May 2001 / Revised version: 13 June 2001 / Published online: 24 August 2001 -© Springer-Verlag / Società Italiana di Fisica 2001 )

Abstract
In relativistic heavy ion collisions, top quarks can be produced by photon-gluon fusion when a photon from the Weizsäcker-Williams virtual photon field of one nucleus interacts with a gluon in the other nucleus. Photoproduction with heavy ions at the Large Hadron Collider (LHC) will be the first accessible non-hadronic top production channel. We calculate the photoproduction cross sections, pair mass and top quark rapidity distributions in peripheral lead-lead and oxygen-oxygen collisions. The cross sections are sensitive to the top quark charge and the large-Q² gluon distribution in the nucleus. We find a cross section of 15 pb in oxygen-oxygen collisions, leading to 210 pairs in a one month (10⁶ s) LHC run. In pA collisions, the rate is higher, 1100 pairs per month for pO. A comparison of the AA and pA data might allow for a study of gluon shadowing at high Q².

© Società Italiana di Fisica, Springer-Verlag 2001