4,163 research outputs found
New Bounds on R-parity Violating Couplings
We use information from rare nonleptonic decays of heavy-quark mesons to put
new bounds on the magnitudes of certain product combinations of baryon
nonconserving R-parity violating couplings in supersymmetric models. Product
combinations of lepton and baryon nonconserving R-parity violating couplings
are also considered in the light of existing bounds on nucleon decay. Contrary
to popular impression, a few such combinations are shown to remain essentially
unconstrained.Comment: Latex file, 16 pages including 6 uuencoded Postscript files appended.
Figures also available via anonymous ftp at ftp://physics.wm.edu/pub/ (get
rparity*.ps). Revised version corrects a few sentences in introduction and
adds some reference
Search for a Scalar Bottom Quark with Mass 3.5-4.5 GeV/
We report on a search for a supersymmetric meson with mass
between 3.5 and 4.5 GeV/ using 4.52 of integrated
luminosity produced at GeV, just below the threshold, and collected with the CLEO detector. We find no evidence
for a light scalar bottom quark.Comment: 10 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
Study of Charmless Hadronic B Meson Decays to Pseudoscalar-Vector Final States
We report results of searches for charmless hadronic B meson decays to
pseudoscalar(pi^+-,K^+-,Pi^0 or Ks^0)-vector(Rho, K* or Omega) final states.
Using 9.7 million BBbar pairs collected with the CLEO detector, we report 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 the other decay modes
investigated.Comment: 10 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
Observation of New States Decaying into
Using 13.7 fb^{-1} of data recorded by the CLEO detector at CESR, we
investigate the spectrum of charmed baryons which decay into Lambda_c^+ pi^-
pi^+ and are more massive than the Lambda_{c1} baryons. We find evidence for
two new states: one is broad and has an invariant mass roughly 480 MeV above
that of the Lambda_c^+; the other is narrow with an invariant mass of 596 +- 1
+- 2 MeV above the Lambda_c^+ mass. These results are preliminary.Comment: 11 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
First Observation of the Baryon and a New Measurement of the Mass
Using data recorded with the CLEO II and CLEO II.V detector configurations at
the Cornell Electron Storage Rings, we report the first observation and mass
measurement of the charmed baryon, and an updated measurement
of the mass of the baryon. We find
= 231.0 +- 1.1 +- 2.0 MeV, and
= 166.4 +- 0.2 +- 0.3 MeV, where the errors are
statistical and systematic respectively.Comment: 8 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
Measurements of the Mass, total Width and Two-Photon Partila Width of the Meson
Using 13.4 of data collected with the CLEO detector at the Cornell
Electron Storage Ring, we have observed 300 events for the two-photon
production of ground-state pseudo-scalar charmonium in the decay ->
. We have measured the mass to be (2980.4 +-
2.3 (stat) +- 0.6 (sys)) MeV and its full width as (27.0 +- 5.8 (stat) +- 1.4
(sys)) MeV. We have determined the two-photon partial width of the
meson to be (7.6 +- 0.8 (stat) +- 0.4 (sys) +- 2.3 (br)) keV, with the last
uncertainty associated with the decay branching fraction.Comment: 9 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
Study of exclusive two-body B0 meson decays to charmonium
We present a study of three B0 decay modes useful for time-dependent CP
asymmetry measurements. From a sample of 9.7 million B meson pairs collected
with the CLEO detector, we have reconstructed B0 -> J/psi K0S, B0 -> chi_c1
K0S, and B0 -> J/psi pi0 decays. The latter two decay modes have been observed
for the first time. We describe a K0S -> pi0 pi0 detection technique and its
application to the reconstruction of the decay B0 -> J/psi K0S. Combining the
results obtained using K0S -> pi+ pi- and K0S -> pi0 pi0 decays, we determine
Br(B0 -> J/psi K0) = (9.5 +- 0.8 +- 0.6)*10^-4, where the first uncertainty is
statistical and the second one is systematic.
We also obtain Br(B0 -> chi_c1 K0)= (3.9 +1.9/-1.3 +- 0.4)*10^-4 and Br(B0 ->
J/psi pi0) = (2.5 +1.1/-0.9 +- 0.2)*10^-5.Comment: 11 pages, 2 figures, submitted to Phys. Rev.
Hadronic Structure in the Decay
We report on a study of the invariant mass spectrum of the hadronic system in
the decay tau- -> pi- pi0 nu_tau. This study was performed with data obtained
with the CLEO II detector operating at the CESR e+ e- collider. We present fits
to phenomenological models in which resonance parameters associated with the
rho(770) and rho(1450) mesons are determined. The pi- pi0 spectral function
inferred from the invariant mass spectrum is compared with data on e+ e- -> pi+
pi- as a test of the Conserved Vector Current theorem. We also discuss the
implications of our data with regard to estimates of the hadronic contribution
to the muon anomalous magnetic moment.Comment: 39 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
Measurement of the B0 and B+ meson masses from B0 -> psi(') K_S and B+ -> psi(') K+ decays
Using 9.6 million B meson pairs collected with the CLEO detector, we have
fully reconstructed 135 B0 -> psi(') K_S and 526 B+ -> psi(') K+ candidates
with very low background.
We fitted the psi(')K invariant mass distributions of these B meson
candidates and measured the masses of the neutral and charged B mesons to be
M(B0)=5279.1+-0.7[stat]+-0.3[syst] MeV/c^2 and
M(B+)=5279.1+-0.4[stat]+-0.4[syst] MeV/c^2. The precision is a significant
improvement over previous measurements.Comment: 2 typographic errors corrected; 11 pages, 2 figures; also available
through http://www.lns.cornell.edu/public/CLNS/CLEO.htm
Observation of Radiative Leptonic Decay of the Tau Lepton
Using 4.68 fb^{-1} of e^+e^- annihilation data collected with the CLEO II
detector at the Cornell Electron Storage Ring (CESR) we have studied tau
radiative decays tau -> mu nu nu gamma and tau -> e nu nu gamma. For a 10 MeV
minimum photon energy in the tau rest frame, the branching fraction of
radiative tau decay to a muon or electron is measured to be
(3.61+-0.16+-0.35)*10^{-3} or (1.75+-0.06+-0.17)*10^{-2}, respectively. The
branching fractions are in agreement with the Standard Model theoretical
predictions.Comment: 11 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
- …