We present a study of the decays B+ -> DK+ with D mesons reconstructed in the K+pi(-)pi(0) or K-pi(+)pi(0) final states, where D indicates a D-0 or a (D) over bar (0) meson. Using a sample of 474 x 10(6) B (B) over bar pairs collected with the BABAR detector at the PEP- II asymmetric- energy e(+)e(-) collider at SLAC, we measure the ratios R +/- equivalent to Gamma(B+->[K--/+pi(+)pi(0)](D)K+)/Gamma(B+->[K+pi(-/+)pi(0)](D)K+). We obtain R+ = (5(-10)(+12)(stat)(4)(2)(syst)) X 10(-3) and R- = (12(-10)(+12)(stat)(-5)(+3)(syst)) X 10(-3), from which we extract the upper limits at 90% probability: R+ < 23 X 10(-3) and R- < 29 X 10(-3). Using these measurements, we obtain an upper limit for the ratio r(B) of the magnitudes of the b -> u and b -> c amplitudes r(B) < 0.13 at 90% probability.
Search for b -> u transitions in B-+/- -> [K--/+pi(+/-)pi(0)](D)K-+/- decays
FERRONI, Fernando
2011-01-01
Abstract
We present a study of the decays B+ -> DK+ with D mesons reconstructed in the K+pi(-)pi(0) or K-pi(+)pi(0) final states, where D indicates a D-0 or a (D) over bar (0) meson. Using a sample of 474 x 10(6) B (B) over bar pairs collected with the BABAR detector at the PEP- II asymmetric- energy e(+)e(-) collider at SLAC, we measure the ratios R +/- equivalent to Gamma(B+->[K--/+pi(+)pi(0)](D)K+)/Gamma(B+->[K+pi(-/+)pi(0)](D)K+). We obtain R+ = (5(-10)(+12)(stat)(4)(2)(syst)) X 10(-3) and R- = (12(-10)(+12)(stat)(-5)(+3)(syst)) X 10(-3), from which we extract the upper limits at 90% probability: R+ < 23 X 10(-3) and R- < 29 X 10(-3). Using these measurements, we obtain an upper limit for the ratio r(B) of the magnitudes of the b -> u and b -> c amplitudes r(B) < 0.13 at 90% probability.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
