37 research outputs found
Heavy Quark Spectroscopy -- Theory Overview
Some recent discoveries in the spectroscopy of hadrons containing heavy
quarks, and some of their theoretical interpretations, are reviewed.Comment: 13 pages, 6 figures. Presented at Second Meeting of APS Topical Group
on Hadron Physics, Nashville, TN, 22-24. Proceedings to be published by
Journal of Physics (UK), Conference Series. Uses jpconf.cls, jpconf11.clo.
Some corrections; references update
Updated Measurement of the Strong Phase in D0 --> K+pi- Decay Using Quantum Correlations in e+e- --> D0 D0bar at CLEO
We analyze a sample of 3 million quantum-correlated D0 D0bar pairs from 818
pb^-1 of e+e- collision data collected with the CLEO-c detector at E_cm = 3.77
GeV, to give an updated measurement of \cos\delta and a first determination of
\sin\delta, where \delta is the relative strong phase between doubly
Cabibbo-suppressed D0 --> K+pi- and Cabibbo-favored D0bar --> K+pi- decay
amplitudes. With no inputs from other experiments, we find \cos\delta = 0.81
+0.22+0.07 -0.18-0.05, \sin\delta = -0.01 +- 0.41 +- 0.04, and |\delta| = 10
+28+13 -53-0 degrees. By including external measurements of mixing parameters,
we find alternative values of \cos\delta = 1.15 +0.19+0.00 -0.17-0.08,
\sin\delta = 0.56 +0.32+0.21 -0.31-0.20, and \delta = (18 +11-17) degrees. Our
results can be used to improve the world average uncertainty on the mixing
parameter y by approximately 10%.Comment: Minor revisions, version accepted by PR
Dalitz Plot Analysis of Ds to K+K-pi+
We perform a Dalitz plot analysis of the decay Ds to K+K-pi+ with the CLEO-c
data set of 586/pb of e+e- collisions accumulated at sqrt(s) = 4.17 GeV. This
corresponds to about 0.57 million D_s+D_s(*)- pairs from which we select 14400
candidates with a background of roughly 15%. In contrast to previous
measurements we find good agreement with our data only by including an
additional f_0(1370)pi+ contribution. We measure the magnitude, phase, and fit
fraction of K*(892) K+, phi(1020)pi+, K0*(1430)K+, f_0(980)pi+, f_0(1710)pi+,
and f_0(1370)pi+ contributions and limit the possible contributions of other KK
and Kpi resonances that could appear in this decay.Comment: 21 Pages,available through http://www.lns.cornell.edu/public/CLNS/,
submitted to PR
Search for D0 to p e- and D0 to pbar e+
Using data recorded by CLEO-c detector at CESR, we search for simultaneous
baryon and lepton number violating decays of the D^0 meson, specifically, D^0
--> p-bar e^+, D^0-bar --> p-bar e^+, D^0 --> p e^- and D^0-bar --> p e^-. We
set the following branching fraction upper limits: D^0 --> p-bar e^+ (D^0-bar
--> p-bar e^+) p e^- (D^0-bar --> p e^-) < 1.2 *
10^{-5}, both at 90% confidence level.Comment: 10 pages, available through http://www.lns.cornell.edu/public/CLNS/,
submitted to PRD. Comments: changed abstract, added reference for section 1,
vertical axis in Fig.5 changed (starts from 1.5 rather than 2.0), fixed typo
Charmonium decays to gamma pi0, gamma eta, and gamma eta'
Using data acquired with the CLEO-c detector at the CESR e+e- collider, we
measure branching fractions for J/psi, psi(2S), and psi(3770) decays to gamma
pi0, gamma eta, and gamma eta'. Defining R_n = B[ psi(nS)-->gamma eta ]/B[
psi(nS)-->gamma eta' ], we obtain R_1 = (21.1 +- 0.9)% and, unexpectedly, an
order of magnitude smaller limit, R_2 < 1.8% at 90% C.L. We also use
J/psi-->gamma eta' events to determine branching fractions of improved
precision for the five most copious eta' decay modes.Comment: 14 pages, available through http://www.lns.cornell.edu/public/CLNS/,
published in Physical Review
Precision Measurement of B(D+ -> mu+ nu) and the Pseudoscalar Decay Constant fD+
We measure the branching ratio of the purely leptonic decay of the D+ meson
with unprecedented precision as B(D+ -> mu+ nu) = (3.82 +/- 0.32 +/-
0.09)x10^(-4), using 818/pb of data taken on the psi(3770) resonance with the
CLEO-c detector at the CESR collider. We use this determination to derive a
value for the pseudoscalar decay constant fD+, combining with measurements of
the D+ lifetime and assuming |Vcd| = |Vus|. We find fD+ = (205.8 +/- 8.5 +/-
2.5) MeV. The decay rate asymmetry [B(D+ -> mu+ nu)-B(D- -> mu- nu)]/[B(D+ ->
mu+ nu)+B(D- -> mu- nu)] = 0.08 +/- 0.08, consistent with no CP violation. We
also set 90% confidence level upper limits on B(D+ -> tau+ nu) < 1.2x10^(-3)
and B(D+ -> e+ nu) < 8.8x10^(-6).Comment: 24 pages, 11 figures and 6 tables, v2 replaced some figure vertical
axis scales, v3 corrections from PRD revie
Inclusive chi_bJ(nP) Decays to D0 X
Using Upsilon(2S) and Upsilon(3S) data collected with the CLEO III detector
we have searched for decays of chi_bJ to final states with open charm. We fully
reconstruct D0 mesons with p_D0 > 2.5 GeV/c in three decay modes (K-pi+,
K-pi+pi0, and K-pi-pi+pi+) in coincidence with radiative transition photons
that tag the production of one of the chi_bJ(nP) states. We obtain significant
signals for the two J=1 states. Recent NRQCD calculations of chi_{bJ}(nP) --> c
cbar X depend on one non-perturbative parameter per chi_bJ triplet. The
extrapolation from the observed D0 X rate over a limited momentum range to a
full c cbar X rate also depends on these same parameters. Using our data to fit
for these parameters, we extract results which agree well with NRQCD
predictions, confirming the expectation that charm production is largest for
the J=1 states. In particular, for J=1, our results are consistent with c cbar
g accounting for about one-quarter of all hadronic decays.Comment: Version 2 updates include corrections to important errors in Table V
and VII column headers which summarize results, and additional minor edits.
17 pages, available through http://www.lns.cornell.edu/public/CLNS
Evidence for Decays of h_c to Multi-Pion Final States
Using a sample of 2.59 x 10^7 psi(2S) decays collected by the CLEO--c
detector, we present results of a search for the decay chain psi(2S) -> pi^0
h_c, h_c -> n(pi^+ pi^-) pi^0, n=1,2,3. We observe no significant signals for
n=1 and n=3 and set upper limits for the corresponding decay rates. First
evidence for the decay h_c {\o}pi^+ pi^- pi^+ pi^- pi^0 is presented, and a
product branching fraction of B(psi(2S) -> h_c) x B(h_c -> 2(pi^+ pi^-)
pi^0)=1.88^{+0.48+0.47}_{-0.45-0.30} x 10^{-5} is measured. This result implies
that h_c -> hadrons and h_c -> gamma eta_c have comparable rates, in
agreement with expectations.Comment: Available through http://www.lns.cornell.edu/public/CLNS/, submitted
to Phys. Rev. D. (Rapid Communications
Ds+ Exclusive Hadronic Decays Involving omega
Using data collected near the Ds*+ Ds- peak production energy Ecm=4170 MeV by
the CLEO-c detector, we search for Ds+ exclusive hadronic decays involving
omega. We find B(Ds+ -> pi+ omega) = (0.21 +- 0.09 +- 0.01)%, B(Ds+ -> pi+ pi0
omega) = (2.78 +- 0.65 +- 0.25)%, B(Ds+ -> pi+ pi+ pi- omega) = (1.58 +- 0.45
+- 0.09)%, B(Ds+ -> pi+ eta omega) = (0.85 +- 0.54 +- 0.06)%, B(Ds+ -> K+
omega) K+ pi0 omega) K+ pi+ pi- omega)
K+ eta omega) <0.79%. The upper limits are at 90%
confidence level.Comment: 8 pages, 3 figures, available through
http://www.lns.cornell.edu/public/CLNS/, submitted to PR