The estimation of the effective centre-of-mass energy in q(q)over-bar gamma events from DELPHI

Authors
Abreu, P De Angelis, A Della Ricca, G Fassouliotis, D Grefrath, A Kjaer, N Henriques, RP Mulders, M Pimenta, M Vitale, L
Citation
P. Abreu et al., The estimation of the effective centre-of-mass energy in q(q)over-bar gamma events from DELPHI, NUCL INST A, 427(3), 1999, pp. 487-494
Citations number
11
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences","Instrumentation & Measurement
Journal title
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
ISSN journal
01689002 → ACNP
Volume
427
Issue
3
Year of publication
1999
Pages
487 - 494
Database
ISI
SICI code
0168-9002(19990521)427:3<487:TEOTEC>2.0.ZU;2-B
Abstract
The photon radiation in the initial state lowers the energy available for t he e(+)e(-) collisions; this effect is particularly important at LEP2 energ ies (above the mass of the Z boson). Being aligned to the beam direction, s uch initial state radiation is mostly undetected. This article describes th e procedure used by the DELPHI experiment at LEP to estimate the effective centre-of-mass energy in hadronic events collected at energies above the Z peak. Typical resolutions ranging from 2 to 3 GeV on the effective center-o f-mass energy are achieved, depending on the event topology. (C) 1999 Elsev ier Science B.V. All rights reserved.