Eur. Phys. J. A 14, 199-206 (2002)
DOI: 10.1140/epja/i2001-10121-4
-radiation of excited nuclear discrete
levels in peripheral heavy ion collisions
V.L. Korotkikh and K.A. Chikin Scobeltsyn Institute of Nuclear Physics, Moscow State University, 119899 Moscow, Russia vlk@lav01.sinp.msu.ru
(Received: 14 December 2001 Communicated by by W. Henning)
Abstract
A new process of a nuclear excitation to discrete states in peripheral heavy ion collisions is studied.
High-energy photons are emitted by the exited nuclei with energies up to a few tens of GeV at angles of a few hundred microradians
with respect to the beam direction. We show that a two-stage process, where an electron-positron pair
is produced by virtual photons emitted by nuclei and then the electron or positron excites the nucleus,
has a large cross-section. It is equal to about 5 b for CaCa collisions.
On the one hand, it produces a significant
-rays background in the nuclear fragmentation region but,
on the other hand, it could be used for monitoring the nuclear beam intensity at the LHC.
These secondary nuclear photons could be a good signal for triggering peripheral nuclear collisions.
25.75.-q - Relativistic heavy ion collisions.
© Società Italiana di Fisica, Springer-Verlag 2002
