Observation of e{sup +}e{sup -}{yields}{rho}{sup +}{rho}{sup -} near {radical}(s)=10.58 GeV

Journal Article · Wed Oct 01 04:00:00 EDT 2008 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.78.071103· OSTI ID:21254237

Aubert, B; Bona, M; Karyotakis, Y; Lees, J P; Poireau, V; Prencipe, E; Prudent, X; Tisserand, V ^[1]; Tico, J Garra; Grauges, E ^[2]; Lopez, L; Palano, A; Pappagallo, M ^[3]; Eigen, G; Stugu, B; Sun, L ^[4]; Abrams, G S; Battaglia, M; Brown, D N; Cahn, R N ^[5]

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1. Laboratoire de Physique des Particules, IN2P3/CNRS et Universite de Savoie, F-74941 Annecy-Le-Vieux (France)
2. Universitat de Barcelona, Facultat de Fisica, Departament ECM, E-08028 Barcelona (Spain)
3. INFN Sezione di Bari, I-70126 Bari (Italy)
4. University of Bergen, Institute of Physics, N-5007 Bergen (Norway)
5. Lawrence Berkeley National Laboratory and University of California, Berkeley, California 94720 (United States)

We report the first observation of e{sup +}e{sup -}{yields}{rho}{sup +}{rho}{sup -}, in a data sample of 379 fb{sup -1} collected with the BABAR detector at the PEP-II e{sup +}e{sup -} storage ring at center-of-mass energies near {radical}(s)=10.58 GeV. We measure a cross section of {sigma}(e{sup +}e{sup -}{yields}{rho}{sup +}{rho}{sup -})=8.3{+-}0.7(stat){+-}0.8(syst) fb within the range of |cos{theta}*|<0.8 and |cos{theta}{sub {+-}}|<0.85, where {theta}* is the center-of-mass polar angle of the {rho}{sup {+-}} meson and {theta}{sub {+-}} are the angles in the {rho}{sup {+-}} rest frame between the direction of the boost from the laboratory frame and the direction of the {pi}{sup {+-}}. Assuming production through single-photon annihilation, there are three independent helicity amplitudes. We measure the ratios of their squared moduli to be |F{sub 00}|{sup 2} ratio |F{sub 10}|{sup 2} ratio |F{sub 11}|{sup 2}= 0.51{+-}0.14(stat){+-}0.07(syst) ratio 0.10{+-}0.04(stat){+-}0.01(syst) ratio 0.04{+-}0.03(stat){+-}0.01(syst). The |F{sub 00}|{sup 2} result is inconsistent with the prediction of 1.0 made by QCD models with a significance of 3.1 standard deviations including systematic uncertainties.

• OSTI ID: 21254237
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 7 Vol. 78; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
ANNIHILATION
CENTER-OF-MASS SYSTEM
CROSS SECTIONS
ELECTRON-POSITRON COLLISIONS
FORECASTING
GEV RANGE 01-10
HELICITY
MESONS
PEP STORAGE RINGS
PHOTONS
QUANTUM CHROMODYNAMICS