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Title: Exclusive {rho}{rho} production in {gamma}{gamma} interaction at LEP

Abstract

Exclusive {rho}{rho} production in two-photon collisions is studied at LEP for quasi-real photons ({gamma}{gamma}, centre-of-mass energies 161 GeV {<=} {radical}(s) {<=} 209 GeV, total integrated luminosity L=698 pb-1) and one virtual photon ({gamma}{gamma}*, 89 GeV {<=} {radical}(s) 209 GeV, L=855 pb-1). The cross sections of the {rho}{rho} production processes are determined as a function of the photon virtuality, Q2, and the two-photon centre-of-mass energy, W{gamma}{gamma}, in the kinematic region: Q2 {<=} 30 GeV2 and 1 GeV {<=} W{gamma}{gamma} {<=} 3 GeV.

Authors:
 [1]
  1. Carnegie Mellon University, Pittsburgh, PA 15213 (United States)
Publication Date:
OSTI Identifier:
21056838
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 892; Journal Issue: 1; Conference: QCHS7: 7. conference on quark confinement and the hadron spectrum, Ponta Delgada, Acores (Portugal), 2-7 Sep 2006; Other Information: DOI: 10.1063/1.2714400; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA). L3 Collaboration
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CROSS SECTIONS; EXCLUSIVE INTERACTIONS; FOUR MOMENTUM TRANSFER; GEV RANGE; LEP STORAGE RINGS; MULTIPARTICLE SPECTROMETERS; PARTICLE IDENTIFICATION; PARTICLE KINEMATICS; PARTICLE PRODUCTION; PHOTON-PHOTON INTERACTIONS; PHOTONS; RHO-770 MESONS

Citation Formats

Vorobiev, Igor. Exclusive {rho}{rho} production in {gamma}{gamma} interaction at LEP. United States: N. p., 2007. Web. doi:10.1063/1.2714400.
Vorobiev, Igor. Exclusive {rho}{rho} production in {gamma}{gamma} interaction at LEP. United States. doi:10.1063/1.2714400.
Vorobiev, Igor. Tue . "Exclusive {rho}{rho} production in {gamma}{gamma} interaction at LEP". United States. doi:10.1063/1.2714400.
@article{osti_21056838,
title = {Exclusive {rho}{rho} production in {gamma}{gamma} interaction at LEP},
author = {Vorobiev, Igor},
abstractNote = {Exclusive {rho}{rho} production in two-photon collisions is studied at LEP for quasi-real photons ({gamma}{gamma}, centre-of-mass energies 161 GeV {<=} {radical}(s) {<=} 209 GeV, total integrated luminosity L=698 pb-1) and one virtual photon ({gamma}{gamma}*, 89 GeV {<=} {radical}(s) 209 GeV, L=855 pb-1). The cross sections of the {rho}{rho} production processes are determined as a function of the photon virtuality, Q2, and the two-photon centre-of-mass energy, W{gamma}{gamma}, in the kinematic region: Q2 {<=} 30 GeV2 and 1 GeV {<=} W{gamma}{gamma} {<=} 3 GeV.},
doi = {10.1063/1.2714400},
journal = {AIP Conference Proceedings},
number = 1,
volume = 892,
place = {United States},
year = {Tue Feb 27 00:00:00 EST 2007},
month = {Tue Feb 27 00:00:00 EST 2007}
}
  • Using the new data accumulated at CLEO over the past year, the authors have updated their search for the decays, B {yields} {rho}{gamma} and B {yields} {omega}{gamma}, and their measurement of B {yields} K{sup *}{gamma}. They combine these measurements with different theoretical models to find an upper limit on the ratio between the CKM matrix elements, V{sub td} and V{sub ts}.
  • Nuclear transparencies measured in exclusive incoherent [rho][sup 0] meson production from hydrogen, deuterium, carbon, calcium, and lead in muon-nucleus scattering are reported. The data were obtained with the E665 spectrometer using the Fermilab Tevatron muon beam with a mean beam energy of 470 GeV. Increases in the nuclear transparencies are observed as the virtuality of the photon increases, in qualitative agreement with the expectations of color transparency.
  • Preliminary results on the measurement of nuclear transparencies from exclusive incoherent {rho}{sup 0} meson production off deuterium, carbon, calcium, and lead, normalized to hydrogen, and coherent {rho}{sup 0} meson production off calcium and lead, normalized to carbon, in deep-inelastic muon-nucleus scattering are reported. The data were collected with the E665 spectrometer using the Fermilab Tevatron muon beam with a mean beam energy of 470 GeV. Increases in the transparencies are observed in both coherent and incoherent production as the virtuality of the photon increases, as expected of color transparency. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.
  • The cross section for production of rho/sup 0/ mesons has been measured in the reaction e + p ..-->.. e + p + ..pi../sup +/ + ..pi../sup -/. The cross section is presented as a function of W, the c.m. energy of the virtual-photon-proton system, and -Q/sup 2/, the square of the virtual-photon mass. The vector-dominance model is not able to describe the dependence of the cross section on the parameters Q/sup 2/ and W. The slope parameter B describing the scattering of the proton exhibits a significant variation with Q/sup 2/.
  • Evidence is presented for the production of chi/sub b//sup prime/ states (2 /sup 3/P) in the reaction UPSILON''..--> gamma..chi/sub b//sup prime/..--> gamma gamma..UPSILON' (or ..gamma gamma..UPSILON) with subsequent decay of the UPSILON' (UPSILON) into e/sup +/e/sup -/ or ..mu../sup +/..mu../sup -/. The data were obtained with the nonmagnetic CUSB detector at the Cornell e/sup +/e/sup -/ storage ring. Observed were 14 (15) events consistent with the transition to the UPSILON' (UPSILON) with an estimated background of 1.7 (1.3) events. The lower-energy photons cluster around 100 MeV, implying M(UPSILON'')-M(chi/sub b//sup prime/)approx.100 MeV. A single line interpretation of the lower-energy photon spectrummore » is disfavored.« less