M. Guida

A study of the multigap RPC at the gamma irradiation facility at CERN

Abstract The selected device for the ALICE Time-of-Flight array is the Multigap Resistive Plate Chamber (MRPC). We have tested this device at the Gamma Irradiation Facility at CERN to evaluate the rate dependence. We find that the rate capability of the MRPC easily exceeds the 50 Hz/cm 2 maximum expected rate at the ALICE experiment. In addition, we have measured the power dissipated for an equivalent flux of 1.6 kHz/cm 2 of through-going muons to be 650 mW/m 2 .

Rejection power of a horizontal RPC telescope for left and right coming cosmic muons

Abstract The possibility of performing neutrino astronomy by means of a detector above the ground depends critically on the feasibility of a rejection power on the order of 10 11 required to discriminate the enormous background of cosmic downward going muons from the signal of upward going muons produced by neutrinos. In order to check whether and how this rejection is obtainable, we have built in the Physics Department of the University of Bari a horizontal cosmic muon telescope (MINI) instrumented with resistive plate counters. By performing time-of-flight measurements, we have estimated the rejection power of our telescope for left and right coming cosmic muons. The rejection dependence on a few fundamental parameters like minimum number of points per track, telescope length, RPC time resolution and on trigger configuration has been investigated.

Study of QGP signatures with the ϕ → K + K – signal in Pb-Pb ALICE events

The φ → KK decay channel in Pb-Pb collisions at LHC is studied through a full simulation of the ALICE detector. The study focuses on possible signatures in this channel of quark-gluon plasma (QGP) formation. On a basis of 10 collisions at high centrality some proposed QGP signatures are clearly visible both in KK invariant mass and transverse mass distributions. The high significance of this observation appears to reside heavily on the use of the TOF (Time Of Flight) system of ALICE in addition to its central tracking detectors. PACS. PACS-key discribing text of that key – PACS-key discribing text of that key

A multiplicity trigger based on the Time of Flight detector for the ALICE experiment

The goal of the ALICE Time of Flight detector, based on MRPC technology, is to perform charged particle identification in |η|<1. This large area (150 m), finely segmented detector (~160,000 channels), provides fast signals which will contribute to the Level 0 and Level 1 trigger decisions. We use the TOF detector information to perform an online estimate of the total track multiplicity and to identify simple and peculiar topologies like those produced by peripheral collisions and by cosmic muons. The system architecture foresees a first layer of 72 VME boards interfacing the detector front-end to a second layer, which receives and processes all the information and takes trigger decisions.