262 research outputs found
Measurement of the Branching Fraction for B- --> D0 K*-
We present a measurement of the branching fraction for the decay B- --> D0
K*- using a sample of approximately 86 million BBbar pairs collected by the
BaBar detector from e+e- collisions near the Y(4S) resonance. The D0 is
detected through its decays to K- pi+, K- pi+ pi0 and K- pi+ pi- pi+, and the
K*- through its decay to K0S pi-. We measure the branching fraction to be
B.F.(B- --> D0 K*-)= (6.3 +/- 0.7(stat.) +/- 0.5(syst.)) x 10^{-4}.Comment: 7 pages, 1 postscript figure, submitted to Phys. Rev. D (Rapid
Communications
Study of e+e- --> pi+ pi- pi0 process using initial state radiation with BABAR
The process e+e- --> pi+ pi- pi0 gamma has been studied at a center-of-mass
energy near the Y(4S) resonance using a 89.3 fb-1 data sample collected with
the BaBar detector at the PEP-II collider. From the measured 3pi mass spectrum
we have obtained the products of branching fractions for the omega and phi
mesons, B(omega --> e+e-)B(omega --> 3pi)=(6.70 +/- 0.06 +/- 0.27)10-5 and
B(phi --> e+e-)B(phi --> 3pi)=(4.30 +/- 0.08 +/- 0.21)10-5, and evaluated the
e+e- --> pi+ pi- pi0 cross section for the e+e- center-of-mass energy range
1.05 to 3.00 GeV. About 900 e+e- --> J/psi gamma --> pi+ pi- pi0 gamma events
have been selected and the branching fraction B(J/psi --> pi+ pi- pi0)=(2.18
+/- 0.19)% has been measured.Comment: 21 pages, 37 postscript figues, submitted to Phys. Rev.
A search for the decay
We search for the rare flavor-changing neutral-current decay in a data sample of 82 fb collected with the {\sl BABAR}
detector at the PEP-II B-factory. Signal events are selected by examining the
properties of the system recoiling against either a reconstructed hadronic or
semileptonic charged-B decay. Using these two independent samples we obtain a
combined limit of
at the 90% confidence level. In addition, by selecting for pions rather than
kaons, we obtain a limit of using only the hadronic B reconstruction method.Comment: 7 pages, 8 postscript figures, submitted to Phys. Rev. Let
High-reflectivity broadband distributed Bragg reflector lattice matched to ZnTe
We report on the realization of a high quality distributed Bragg reflector
with both high and low refractive index layers lattice matched to ZnTe. Our
structure is grown by molecular beam epitaxy and is based on binary compounds
only. The high refractive index layer is made of ZnTe, while the low index
material is made of a short period triple superlattice containing MgSe, MgTe,
and ZnTe. The high refractive index step of Delta_n=0.5 in the structure
results in a broad stopband and the reflectivity coefficient exceeding 99% for
only 15 Bragg pairs.Comment: 4 pages, 3 figure
Observation of the Decay B=> J/psi eta K and Search for X(3872)=> J/psi eta
We report the observation of the meson decay
and evidence for the decay , using {90} million
events collected at the \ensuremath{\Upsilon{(4S)}}\xspace resonance
with the detector at the PEP-II asymmetric-energy storage
ring. We obtain branching fractions of )= and
)=. We search for the new narrow mass state, the
X(3872), recently reported by the Belle Collaboration, in the decay B^\pm\to
X(3872)K^\pm, X(3872)\to \jpsi \eta and determine an upper limit of
(B^\pm \to X(3872) K^\pm \to \jpsi \eta K^\pm)
at 90% C.L.Comment: 7 pages and two figures, submitted to Phys. Rev. Lett
Measurement of Branching Fractions for B0 ->K*2(1430)0 gamma and B+ -> K*2(1430)+ gamma
We have investigated the exclusive, radiative B-meson decay to K_2^*(1430) in
88.5 * 10^6 BBbar events. We present a preliminary measurement of the branching
fractions BR(B->K^*_2(1430)^0 gamma) = (1.22+-0.25+-0.11) * 10^{-5} and
BR(B->K^*_2(1430)^+ gamma) = (1.44+-0.40+-0.13) * 10^{-5}.Comment: 17 pages, 7 postscript figures, contributed to the 21st International
Symposium on Lepton and Photon Interactions at High Energies, 8/11-8/16/2003,
Fermilab, Illinois US
Measurement of the Branching Fractions for Inclusive and Decays to Flavor-tagged , and
We report on the inclusive branching fractions of and of
mesons decaying to , , , , , , , , based on a
sample of 88.9 million events recorded with the detector at
the resonance. Events are selected by completely reconstructing
one and searching for a reconstructed charmed particle in the rest of the
event. We measure the number of charmed and of anti-charmed particles per
decay and derive the total charm yield per decay, , and per decay, where the first uncertainty is
statistical, the second is systematic, and the third reflects the charm
branching-fraction uncertainties.Comment: 8 pages, 6 Encapsulated PostScript figures submitted to Phys. Rev. D
(Rapid Communications
Search for D0-D0bar Mixing Using Semileptonic Decay Modes
Based on an 87-fb dataset collected by the Babar detector at the
PEP-II asymmetric-energy -Factory, a search for --
mixing has been made using the semileptonic decay modes (+c.c.). The use of these modes allows
unambiguous flavor tagging and a combined fit of the decay time and
-- mass difference () distributions. The
high-statistics sample of unmixed semileptonic decays is used to model
the distribution and time-dependence of mixed events directly from
the data. Neural networks are used to select events and reconstruct the
. A result consistent with no charm mixing has been obtained,
. This corresponds to an upper limit
of (90% CL).Comment: submitted to Phys. Rev. D (Rapid Communications
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