Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

First CP Violation Results from BABAR

Technical Report ·
DOI:https://doi.org/10.2172/784765· OSTI ID:784765

The authors present a preliminary measurement of time-dependent CP-violating asymmetries in B{sup 0} {yields} J/{psi}K{sub s}{sup 0} and B{sup 0} {yields} {psi}(2S)K{sub s}{sup 0} decay recorded by the BABAR detector at the PEP-II asymmetric B Factory at SLAC. The data sample consists of 9.0 fb{sup -1} collected at the {Upsilon}(4S) resonance and 0.8 fb{sup -1} off-resonance. One of the neutral B mesons, produced in pairs at the {Upsilon}(4S), is fully reconstructed. The flavor of the other neutral B meson is tagged at the time of its decay, mainly with the charge of identified leptons and kaons. The time difference between the decays is determined by measuring the distance between the decay vertices. Wrong-tag probabilities and the time resolution function are measured with samples of fully-reconstructed semileptonic and hadronic neutral B final states. The value of the asymmetry amplitude, sin2{beta}, is determined from a maximum likelihood fit to the time distribution of 120 tagged B{sup 0} {yields} J/{psi}K{sub s}{sup 0} and B{sup 0} {yields} {psi}(2S)K{sub s}{sup 0} candidates: sin2{beta} = 0.12 {+-} 0.37 (stat) {+-} 0.09 (syst).

Research Organization:
Stanford Linear Accelerator Center, Menlo Park, CA (US)
Sponsoring Organization:
USDOE Office of Energy Research (ER) (US)
DOE Contract Number:
AC03-76SF00515
OSTI ID:
784765
Report Number(s):
SLAC-PUB-8698
Country of Publication:
United States
Language:
English