260 research outputs found
Observation of Two Narrow States Decaying into and
We report the first observation of two narrow charmed strange baryons
decaying to and , respectively, using data from
the CLEO II detector at CESR. We interpret the observed signals as the
and , the symmetric partners
of the well-established antisymmetric and .
The mass differences and
are measured to be and
, respectively.Comment: 11 pages, postscript file also available through
http://w4.lns.cornell.edu/public/CLN
Study of 3-prong Hadronic Decays with Charged Kaons
Using a sample of 4.7/fb integrated luminosity accumulated with the CLEO-II
detector at the Cornell Electron Storage Ring (CESR), we have measured the
branching fractions of the tau lepton into and relative to and relative to . The relative branching fractions are: (5.16+-0.20+-0.50)*,
(1.52+-0.14+-0.29)*, (2.54+-0.44+-0.39)* and at 95%
C.L., respectively. Coupled with additional experimental information, we use
our results to extract information on the structure of three-prong tau decays
to charged kaons.Comment: 16 pages postscript file also available through
http://w4.lns.cornell.edu/public/CLN
Observation of Exclusive Two-Body B Decays to Kaons and Pions
We have studied two-body charmless hadronic decays of B mesons into the final
states , , and . Using 3.3 million pairs
collected with the CLEO-II detector, we have made the first observation of the
decays , , and the sum of and decays (an average over charge-conjugate
states is always implied). We place upper limits on branching fractions for the
remaining decay modes.Comment: 9 page postscript file, postscript file also available through
http://w4.lns.cornell.edu/public/CLN
Measurement of using Partila Reconstruction of
We present a measurement of the absolute branching fraction for using the reconstruction of the decay chain , where only the lepton and the low-momentum pion from
the are detected. With data collected by the CLEO II detector at the
Cornell Electron Storage Ring, we have determined .Comment: 10 page postscript file, postscript file also available through
http://w4.lns.cornell.edu/public/CLN
Search for the Decay
We have searched for the decay of the tau lepton into seven charged particles
and zero or one pi0. The data used in the search were collected with the CLEO
II detector at the Cornell Electron Storage Ring (CESR) and correspond to an
integrated luminosity of 4.61 fb^(-1). No evidence for a signal is found.
Assuming all the charged particles are pions, we set an upper limit on the
branching fraction, B(tau- -> 4pi- 3pi+ (pi0) nu_tau) < 2.4 x 10^(-6) at the
90% confidence level. This limit represents a significant improvement over the
previous limit.Comment: 9 page postscript file, postscript file also available through
http://w4.lns.cornell.edu/public/CLN
Flavor-Specific Inclusive B Decays to Charm
We have measured the branching fractions for B -> D_bar X, B -> D X, and B ->
D_bar X \ell^+ \nu, where ``B'' is an average over B^0 and B^+, ``D'' is a sum
over D^0 and D^+, and``D_bar'' is a sum over D^0_bar and D^-. From these
results and some previously measured branching fractions, we obtain Br(b -> c
c_bar s) = (21.9 3.7)%, Br(b -> s g) K^-
\pi^+) = (3.69 0.20)%. Implications for the ``B semileptonic decay
problem'' (measured branching fraction being below theoretical expectations)
are discussed. The increase in the value of Br(b -> c c_bar s) due to eliminates 40% of the discrepancy.Comment: 12 page postscript file, postscript file also available through
http://w4.lns.cornell.edu/public/CLN
Further Search for the Two-Photon Production of the Glueball Candidate
The CLEOII detector at the Cornell e+ e- storage ring CESR has been used to
search for the two-photon production of the decaying into pi+ pi-.
No evidence for a signal is found in data corresponding to an integrated
luminosity of 4.77/fb and a 95% CL upper limit on of 2.5 eV is set. If this result is combined with the BES Collaboration's
measurement of in radiative decay, a 95% CL
lower limit on the stickiness of the of 73 is obtained. If the
recent CLEO result for \Gamma_{two-photon} * BR{\K_S K_S} is combined with
the present result, the stickiness of the is found to be larger
than 102 at the 95% CL. These results for the stickiness (the ratio of the
probabilities for two-gluon coupling and two-photon coupling) provide further
support for a substantial neutral parton content in the .Comment: 8 pages, postscript file also available through
http://w4.lns.cornell.edu/public/CLN
Search for Lepton-Flavor-Violating Decays of B Mesons
We have searched a sample of 9.6 million BB-bar events for the
lepton-flavor-violating decays B --> h e^{+-} mu^{-+}, B^+ --> h^- e^+ e^+, B^+
--> h^- e^+ mu^+, and B^+ --> h^- mu^+ mu^+, where h is pi, K, rho, and
K*(892), a total of sixteen modes. We find no evidence for these decays, and
place 90% confidence level upper limits on their branching fractions that range
from 1.0 to 8.3 X 10^{-6}.Comment: 8 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, PRD R
Determination of the Michel Parameters and the tau Neutrino Helicity in tau Decay
Using the CLEO II detector at the storage ring CESR, we have
determined the Michel parameters , , and in decay as well as the tau neutrino helicity parameter
in decay. From a data sample of
tau pairs produced at , using events of
the topology and , and the determined sign of , the combined
result of the three samples is: , , , and
. The results are in agreement with
the Standard Model V-A interaction.Comment: 18 page postscript file, postscript file also available through
http://w4.lns.cornell.edu/public/CLN
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