Carregant...
Fitxers
Tipus de document
ArticleVersió
Versió publicadaData de publicació
Si us plau utilitzeu sempre aquest identificador per citar o enllaçar aquest document: https://hdl.handle.net/2445/131518
Observation of e+e−→ρ+ρ− near √s=10.58 GeV
Títol de la revista
ISSN de la revista
Títol del volum
Resum
We report the first observation of e + e − → ρ + ρ − , in a data sample of 379 fb − 1 collected with the BABAR detector at the PEP-II e + e − storage ring at center-of-mass energies near √ s = 10.58 GeV . We measure a cross section of σ ( e + e − → ρ + ρ − ) = 8.3 ± 0.7 ( stat ) ± 0.8 ( syst ) fb within the range of | cos θ ∗ | < 0.8 and | cos θ ± | < 0.85 , where θ ∗ is the center-of-mass polar angle of the ρ ± meson and θ ± are the angles in the ρ ± rest frame between the direction of the boost from the laboratory frame and the direction of the π ± . Assuming production through single-photon annihilation, there are three independent helicity amplitudes. We measure the ratios of their squared moduli to be | F 00 | 2 ∶ | F 10 | 2 ∶ | F 11 | 2 = 0.51 ± 0.14 ( stat ) ± 0.07 ( syst ) ∶ 0.10 ± 0.04 ( stat ) ± 0.01 ( syst ) ∶ 0.04 ± 0.03 ( stat ) ± 0.01 ( syst ) . The | F 00 | 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.
Descripció
Matèries
Matèries (anglès)
Citació
Citació
GARRA TICÓ, Jordi, GRAUGÉS POUS, Eugeni. Observation of e+e−→ρ+ρ− near √s=10.58 GeV. _Physical Review D_. 2008. Vol. 78, núm. 7, pàgs. 071103. [consulta: 1 de desembre de 2025]. ISSN: 1550-7998. [Disponible a: https://hdl.handle.net/2445/131518]