Observation of the Two-photon Decay of the Neutral-k2 Meson


Book Description

An arrangement of spark chambers and scintillation shower detectors was used to investigate the two-photon decay mode of the neutral K2 meson. Twenty-nine candidates were found for this decay mode. However, 12 plus or minus 7 of these events can originate from the neutral-K2 to 3 neutral-pion mode and the CP-violating neutral-K to 2 neutral-pion decay. Monte Carlo simulations indicate that 5 plus or minus of the 12 events are likely to originate from the 3 neutral-pion decays, leaving 7 plus or minus events which may be ascribed to 2 neutral-pion decays. The corresponding branching ratios are: Rate (neutral-K2 to gamma) (neutral-K to all modes) = (1.3 plus or minus 0.6) x 0.0001; Rate 9neutral-K2 to 2 neutral pion)/Rate (Neutral-K2 to all modes) = (1.2 + 1.5 or -1.2) x 0.001.







Measurement of the B/s0 Lifetime in B/s0 --] K+ K- Decays


Book Description

A method is presented to simultaneously separate the contributions to a sample of B{sub (s)}° 2!hh{sup {prime}-} decays, where h = [pi] or K, and measure the B meson lifetimes in the sample while correcting for the bias in the lifetime distributions due to the hadronic trigger at the CDF experiment. Using 1 fb−1 of data collected at CDF the B° lifetime is measured as [tau]{sub B°} = 1.558{sub -0.047}{sup +0.050}{sub stat} ± 0.028{sub syst} ps, in agreement with the world average measurement. The B{sub s}° lifetime in the B{sub s}° 2!KK− decay is measured as [tau]{sub B{sub s}° 2!K+K−} = 1.51{sub -0.11}{sup +0.13}{sub stat} ± 0.04{sub syst} ps. No difference is observed between the lifetime and other measurements of the average B{sub s}° lifetime or the lifetime of the light B{sub s}° mass eigenstate determined from B{sub s}° 2!J/[psi][phi] decays. With the assumptions that B{sub s}° 2!K+K− is 100% CP-even and that [tau]{sub B{sub s}°} = [tau]{sub B°} the width difference in the B{sub s}{sup 0} system is determined as [Delta][Lambda]{sup CP}/[Lambda] = 0.03{sub -0.15}{sup +0.17}{sub stat} ± 0.05{sub syst} using the current world average B{sup 0} lifetime. This is consistent with zero and with the current world average measurement.




Reporting on the Lifetime of Charmless B/s Meson Decay to K+ K-


Book Description

The authors use data collected by the displaced track trigger of the CDF Run II detector at TeVatron to measure the B mesons lifetime in the hadronic decays: B{sub u} {yields} D{sup 0}{pi}, B{sub d} {yields} D{sup {-+}}{pi}{sup {+-}}, B{sub d} {yields} D{sup {-+}}3{pi}, B{sub s} {yields} D{sub s}{sup {-+}}{pi}{sup {+-}}, B{sub s} {yields} D{sub s}{sup {-+}}3{pi}. Recent developments in the measurement of the lifetime of the charmless B{sub s} {yields} K{sup +}k{sup -} mode is presented.