16 research outputs found
CP asymmetries in scalar bottom quark decays
We propose CP asymmetries based on triple product correlations in the decays
sbottom_m -> top chargino_j with subsequent decays of top and chargino_j. For
the subsequent chargino_j decay into a leptonic final state l^- \nu
neutralino_1 we consider the three possible decay chains chargino_j -> l^-
sneutrino -> l^- \nu neutralino_1, chargino_j -> slepton_n \nu -> l^- \nu
neutralino_1 and chargino_j -> W^- neutralino_1 -> l^- \nu neutralino_1. We
consider two classes of CP asymmetries. In the first class it must be possible
to distinguish between different leptonic chargino_j decay chains, whereas in
the second class this is not necessary. We consider also the 2-body decay
chargino_j -> W^- neutralino_1, and we assume that the momentum of the W boson
can be measured. Our framework is the minimal supersymmetric standard model
with complex parameters. The proposed CP asymmetries are non-vanishing due to
non-zero phases for the parameters \mu and/or A_b. We present numerical results
and estimate the observability of these CP asymmetries.Comment: 27 page
Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays
Average charged multiplicities have been measured separately in , and
light quark () events from decays measured in the SLD experiment.
Impact parameters of charged tracks were used to select enriched samples of
and light quark events, and reconstructed charmed mesons were used to select
quark events. We measured the charged multiplicities:
,
, from
which we derived the differences between the total average charged
multiplicities of or quark events and light quark events: and . We compared
these measurements with those at lower center-of-mass energies and with
perturbative QCD predictions. These combined results are in agreement with the
QCD expectations and disfavor the hypothesis of flavor-independent
fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters
Production of pi+, pi-, K+, K-, p and p-bar in Light (uds), c and b Jets from Z0 Decays
We present improved measurements of the differential production rates of
stable charged particles in hadronic Z0 decays, and of charged pions, kaons and
protons identified over a wide momentum range using the SLD Cherenkov Ring
Imaging Detector. In addition to flavor-inclusive Z0 decays, measurements are
made for Z0 decays into light (u, d, s), c and b primary flavors, selected
using the upgraded Vertex Detector. Large differences between the flavors are
observed that are qualitatively consistent with expectations based upon
previously measured production and decay properties of heavy hadrons. These
results are used to test the predictions of QCD in the Modified Leading
Logarithm Approximation, with the ansatz of Local Parton-Hadron Duality, and
the predictions of three models of the hadronization process. The light-flavor
results provide improved tests of these predictions, as they do not include the
contribution of heavy-hadron production and decay; the heavy-flavor results
provide complementary model tests. In addition we have compared hadron and
antihadron production in light quark (as opposed to antiquark) jets.
Differences are observed at high momentum for all three charged hadron species,
providing direct probes of leading particle effects, and stringent constraints
on models.Comment: 44 pages, 14 figs; submitted to Phys. Rev.
Developments in solid state vertex detectors
SIGLEAvailable from British Library Lending Division - LD:8053.4153(RAL--84-123) / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Charge-coupled devices for particle detection with high spatial resolution
SIGLELD:8053.465(RL--80-082) / BLDSC - British Library Document Supply CentreGBUnited Kingdo