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J/{psi} production and decay at the Z resonance

Abstract

In the Large Electron Positron collider (LEP) bunches of electrons and positrons are brought in collision. At a collision energy of 91.2 GeV the Z resonance is excited. The Z boson, the uncharged mediator of the weak force, decays into a particle and an antiparticle almost instantaneously. The probability that in this process heavy quarks charm-anticharm(c anti c) and bottom-antibottom(b anti b) are formed is {approx}12% and {approx}15% respectively. Thus, LEP provides an ideal environment to make precision measurements in the heavy quark sector. The data for this thesis was collected with the L3 detector from 1990-1992. L3 is one of the four experiments at LEP. The integrated luminosity collected by L3 in this period is 43.5 pb{sup -1}. The L3 detector was designed to measure e{sup +}e{sup -} collisions up to 200 GeV with special emphasis on high resolution measurements of photons, electrons and muons. The detector is installed within a magnet providing 0.5 T field. It consists of subdetectors to detect and measure the direction and momentum/energy of charged particles, electromagnetic particles, hadrons and muons. In this thesis the production of the 1{sup 3} S{sub 1} (the j/{psi} meson) and the 2{sup 3} S{sub 1} (the {psi}` meson)  More>>
Authors:
Publication Date:
Oct 13, 1994
Product Type:
Miscellaneous
Report Number:
INIS-mf-15149
Reference Number:
SCA: 662380; 662350; 662360; 662210; 662440; PA: AIX-27:038312; EDB-96:083270; NTS-96:018227; SN: 96001586454
Resource Relation:
Other Information: TH: Proefschrift.; PBD: 13 Oct 1994
Subject:
66 PHYSICS; BEAUTY PARTICLES; WEAK PARTICLE DECAY; ELECTRON-POSITRON INTERACTIONS; ANNIHILATION; KOBAYASHI-MASKAWA MATRIX; MATRIX ELEMENTS; Z NEUTRAL BOSONS; WEAK HADRONIC DECAY; BRANCHING RATIO; EXPERIMENTAL DATA; GEV RANGE 10-100; INCLUSIVE INTERACTIONS; J PSI-3097 MESONS; LEPTONIC DECAY; LIFETIME; NEUTRAL-CURRENT INTERACTIONS; PAIR PRODUCTION; PSI-3685 MESONS; QUARKS
OSTI ID:
222646
Research Organizations:
Rijksuniversiteit Utrecht (Netherlands)
Country of Origin:
Netherlands
Language:
English
Other Identifying Numbers:
Other: ON: DE96623266; TRN: NL96F6184038312
Availability:
INIS; OSTI as DE96623266
Submitting Site:
NLN
Size:
117 p.
Announcement Date:
May 21, 1996

Citation Formats

Vikas, P. J/{psi} production and decay at the Z resonance. Netherlands: N. p., 1994. Web.
Vikas, P. J/{psi} production and decay at the Z resonance. Netherlands.
Vikas, P. 1994. "J/{psi} production and decay at the Z resonance." Netherlands.
@misc{etde_222646,
title = {J/{psi} production and decay at the Z resonance}
author = {Vikas, P}
abstractNote = {In the Large Electron Positron collider (LEP) bunches of electrons and positrons are brought in collision. At a collision energy of 91.2 GeV the Z resonance is excited. The Z boson, the uncharged mediator of the weak force, decays into a particle and an antiparticle almost instantaneously. The probability that in this process heavy quarks charm-anticharm(c anti c) and bottom-antibottom(b anti b) are formed is {approx}12% and {approx}15% respectively. Thus, LEP provides an ideal environment to make precision measurements in the heavy quark sector. The data for this thesis was collected with the L3 detector from 1990-1992. L3 is one of the four experiments at LEP. The integrated luminosity collected by L3 in this period is 43.5 pb{sup -1}. The L3 detector was designed to measure e{sup +}e{sup -} collisions up to 200 GeV with special emphasis on high resolution measurements of photons, electrons and muons. The detector is installed within a magnet providing 0.5 T field. It consists of subdetectors to detect and measure the direction and momentum/energy of charged particles, electromagnetic particles, hadrons and muons. In this thesis the production of the 1{sup 3} S{sub 1} (the j/{psi} meson) and the 2{sup 3} S{sub 1} (the {psi}` meson) and the c anti c bound states are investigated. The leptonic decays of the two mesons (J/{psi}, {psi}`{yields}l{sup +}l{sup -}, l=e, {mu}) provide the cleanest signals of heavy quarks. In this thesis, the {psi}` and J/{psi} mesons have been tagged via their decay into a muon pair. From the invariant mass distribution of the {mu}{sup +}{mu}{sup -} pairs the branching ratio for J/{psi} production at the Z, Br(Z{sup 0}{yields}J/{psi}+X), was determined to be 4.0{+-}0.6(stat.){+-}0.4(sys.)x10{sup -3} while the branching ratio for {psi}` production at the Z is smaller than <2x10{sup -3}. (orig./HSI).}
place = {Netherlands}
year = {1994}
month = {Oct}
}