New Measurement of the Bs Mixing Phase at CDF
The CDF collaboration presents an updated measurement of the CP-violating parameter {beta}{sub s}{sup J/{Psi}{phi}} and of the decay width difference {Delta}{Lambda}{sub s} using approximately 6500 B{sub s} {yields} J/{Psi}{phi} decays collected by the dimuon trigger and reconstructed in a data sample corresponding to 5.2 fb{sup -1} of integrated luminosity. Besides exploiting the two-fold increase in the data sample with respect to the previous measurement, several improvements have been introduced in the analysis including a fully data-driven flavor tagging calibration and proper treatment of possible S-wave contributions. We find that the CP-violating phase is within the range {beta}{sub s}{sup J/{Psi}{phi}} {element_of} [0.02, 0.52] {union} [1.08, 1.55] at 68% C.L. The decay width difference is found to be {Delta}{Lambda}{sub s} = 0.075 {+-} 0.035 (stat) {+-} 0.01 (syst) ps{sup -1}. In addition, we present the most precise mean B{sub s} lifetime {tau}{sub s}, polarization amplitudes |A{sub 0}|{sup 2},|A{sub {parallel}}|{sup 2} and |A{sub {perpendicular}}|{sup 2}, as well as strong phase {delta}{sub {perpendicular}}: {tau}{sub s} = 458.6 {+-} 7.6(stat) {+-} 3.6(syst) {micro}m; |A{sub 0}|{sup 2} = 0.524 {+-} 0.013(stat) {+-} 0.015(syst); |A{sub {parallel}}|{sup 2} = 0.231 {+-} 0.014(stat) {+-} 0.015(syst); and {delta}{sub {perpendicular}} = 2.95 {+-} 0.64(stat) {+-} 0.07(syst).
- Research Organization:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC02-07CH11359
- OSTI ID:
- 1001386
- Report Number(s):
- FERMILAB-CONF-10-494-E; arXiv eprint number arXiv:1012.0962; TRN: US1100352
- Country of Publication:
- United States
- Language:
- English
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