We have measured the branching fraction and photon energy spectrum for the radiative penguin process b-->s gamma. We find Beta(b-->s gamma) = (3.21+/-0.43+/-0.27(+0.18)(-0.10))x10(-4), where the ...errors are statistical, systematic, and from theory corrections. We obtain first and second moments of the photon energy spectrum above 2.0 GeV, <E( gamma)> = 2.346+/-0.032+/-0.011 GeV, and <E(2)(gamma)>-<E(gamma)>(2) = 0.0226+/-0.0066+/-0.0020 GeV(2), where the errors are statistical and systematic. From the first moment, we obtain (in the modified minimal subtraction renormalization scheme, to order 1/M(3)(B) and beta(0)alpha(2)(s)) the heavy quark effective theory parameter Lambda = 0.35+/-0.08+/-0.10 GeV.
First measurement of gamma(D(+)) Ahmed, S; Alam, M S; Athar, S B ...
Physical review letters,
12/2001, Letnik:
87, Številka:
25
Journal Article
Recenzirano
Odprti dostop
We present the first measurement of the D*(+) width using 9/fb of e(+)e(-) data collected near the Upsilon(4S) resonance by the CLEO II.V detector. Our method uses advanced tracking techniques and a ...reconstruction method that takes advantage of the small vertical size of the Cornell Electron-positron Storage Ring beam spot to measure the energy release distribution from the D*(+)-->D(0)pi(+) decay. We find gamma(D*(+)) = 96+/-4 (stat)+/-22 (syst) keV. We also measure the energy release in the decay and compute Delta m identical with m(D*(+))-m(D(0)) = 145.412+/-0.002 (stat)+/-0.012 (syst) MeV/c(2).
Using 13.7 fb(-1) of data recorded by the CLEO detector at the Cornell Electron Storage Ring, we investigate the spectrum of charmed baryons which decay into Lambda+(c)pi(-)pi(+) and are more massive ...than the Lambda+(c)(2625) baryon. We find evidence for two new states: one is broad and has an invariant mass roughly 480 MeV above that of the Lambda+(c) baryon; the other is narrow with an invariant mass of 596+/-1+/-2 MeV above the Lambda+(c) mass.
We report results of searches for charmless hadronic B meson decays to pseudoscalar( pi(+/-), K+/-, pi(0), or K(0)(S))-vector( rho, K(*), or omega) final states. By using 9.7x10(6) BB pairs collected ...with the CLEO detector, we report the first observation of B(-)--->pi(-)rho(0), B(0)-->pi(+/-)rho(-/+), and B(-)-->pi(-)omega, which are expected to be dominated by hadronic b-->u transitions. The measured branching fractions are (10.4(+3.3)(-3.4)+/-2.1)x10(-6), (27.6(+8.4)(-7.4)+/-4.2)x10(-6), and (11.3(+3.3)(-2.9)+/-1. 4)x10(-6), respectively. Branching fraction upper limits are set for all of the other decay modes investigated.
We have measured the first and second moments of the hadronic mass-squared distribution in B-->X(c)l nu, for P(lepton)>1.5 GeV/c. We find <M(2)(X)-M macro(2)(D)> = 0.251+/-0.066 GeV(2), ...<(M(2)(X)-<M(2)(X)>)(2)> = 0.576+/-0.170 GeV(4), where M macro(D) is the spin-averaged D meson mass. From that first moment and the first moment of the photon energy spectrum in b-->s gamma, we find the heavy quark effective theory parameter lambda(1) (in the modified minimal subtraction renormalization scheme, to order 1/M(3)(B) and beta(0)alpha(2)(s)) to be -0.24+/-0.11 GeV(2). Using these first moments and the B semileptonic width, and assuming parton-hadron duality, we obtain absolute value of V(cb) = 0.0404+/-0.0013.
An experimental K-shell photodetachment study of Li(-) giving rise to doubly photoionized Li(+) ions has been carried out at the Advanced Light Source, using a collinear photon-ion beam apparatus. ...The experiment reveals dramatic structure, differing substantially both qualitatively and quantitatively from the corresponding processes above the 1s ionization threshold in Li and Li(+), as predicted by our enhanced R-matrix calculation. The experimental/theoretical comparison shows good agreement over some of the photon energy range, and also reveals some puzzling discrepancies.
Using 13.7 fb(-1) of data recorded by the CLEO detector at Cornell Electron Storage Ring, we report evidence of two new charmed baryons: one decaying into Xi(0')(c)pi(+) with the subsequent decay ...Xi(0')(c)-->Xi(0)(c)gamma, and its isospin partner decaying into Xi(+')(c)pi(-) followed by Xi(+')(c)-->Xi(+)(c)gamma. We measure the following mass differences for the two states: M(Xi(0)(c)gammapi(+))-M(Xi(0)(c)) = 318.2+/-1.3+/-2.9 MeV and M(Xi(+)(c)gammapi(-))-M(Xi(+)(c)) = 324.0+/-1.3+/-3.0 MeV. We interpret these new states as the J(P) = 1 / 2(-) Xi(c1) particles, the charmed-strange analogs of the Lambda(+)(c1)(2593).
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