RadPhi TechNote
radphi-2000-701

The Charged Particle Veto
in the Radphi analysis of all-neutral events

Richard T. Jones
University of Connecticut and Jefferson Lab

July 20, 2000


 
Abstract
Because of the high rate of uncorrelated charged-particle background in the forward region, the Radphi trigger did not incorporate an on-line veto on hits in the CPV counters. The insensitivity of the lead-glass calorimeter to this background allowed us to form a sufficiently selective trigger for all-neutral events without the CPV. In this decision we deferred the problem of how to reject multi-prong hadronic events to the offline. The rates in the CPV under operating conditions were about 80MHz, high enough that even in the offline the application of an efficient charged-particle veto without prohibitive losses from accidental vetos is problematic. In this study I present a method for extracting the component of any spectrum that corresponds to a specific multiplicity in the CPV after randoms have been removed. The method is applied to decompose the spectra of several event variables into pieces of a given charged prong multiplicity.

This study has been superseded by the work reported in
technical note radphi-2004-301.

This material is based upon work supported by the National Science Foundation under Grant No. 0072416.
This page maintained by Richard Jones.