Observation of e+e- Annihilations into the C=+1 Hadronic Final States \rho^0\rho^0 and \phi\rho^0

Aubert, B.

Stanford Linear Accelerator Center

关键词: Storage Rings Experiment-Hep,Hepex, Hepph;    Experiment-Hep,Hepex, Hepph;    43 Particle Accelerators;    Mesons;    Annihilation;   

DOI  :  10.2172/885278
RP-ID  :  SLAC-PUB-11923
RP-ID  :  AC02-76SF00515
RP-ID  :  885278

美国|英语

来源: UNT Digital Library

【 摘 要 】

The authors report the first observation of e{sup +}e{sup -} annihilations into states of positive C-parity, namely {rho}{sup 0}{rho}{sup 0} and {phi}{rho}{sup 0}. The two states are observed in the {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} and K{sup +}K{sup -} {pi}{sup +}{pi}{sup -} final states, respectively, in a data sample of 225 fb{sup -1} collected by the BABAR experiment at the PEP-II e{sup +}e{sup -} storage rings at energies near {radical}s = 10.58 GeV. The distributions of cos {theta}*, where {theta}* is the center-of-mass polar angle of the {phi} meson or the forward {rho}{sup 0} meson, suggest production by two-virtual-photon annihilation. They measure cross sections within the range |cos {theta}*| < 0.8 of {sigma}(e{sup +}e{sup -} {yields} {rho}{sup 0} {rho}{sup 0}) = 20.7 {+-} 0.7(stat) {+-} 2.7(syst) fb and {sigma}(e{sup +}e{sup -} {yields} {phi}{rho}{sup 0}) = 5.7 {+-} 0.5(stat) {+-} 0.8(syst) fb.