30 research outputs found
CP Violation via Interference
We consider , where
decays to and is any hadronic final state, such as or
. We find a large direct CP asymmetry in B-meson decays via
interference. A possible method to determine weak phases, such as ,
is discussed. The experimental feasibility is also shown.Comment: 7 pages, latex(sprocl.sty included), 2 figures. Talk presented at
"Int. Conf. on B-physics and CP violation" Hawaii 9
Test of Various Photocathodes
A test of various photocathodes was carried out. The tested materials were
CsI, CsTe, their multi-layers and so on. The quantum efficiencies of the
various materials were measured under a vacuum and/or after exposure to several
kinds of gases.Comment: 7 pages, Latex format(article), figures included, published in NIM
A343(1994)11
Electron identification using the TOPAZ detector at TRISTAN
We present an electron-identification method using the time-projection
chamber and the lead-glass calorimeter in the TOPAZ detector system. Using this
method we have achieved good electron identification against hadron backgrounds
over a wide momentum range in the hadronic events produced by both
single-photon exchange and two-photon processes. Pion-rejection factors and
electron efficiencies were 163 and 68.4\% for high- electrons and 137 and
42.7\% for low- electrons in the single-photon-exchange process, and 8600
and 36.0\% for the two-photon process, respectively.Comment: 32 pages, latex format (article), 24 figures, submitted for
publication
Direct CP violation in three-body decays of the meson by resonance effects
We discuss direct CP violation in three-body decays of meson such as
, which involves various intermediate resonance
states, such as and , where
represents the resonance. Due to the large final state
interaction phases of the resonances, the CP asymmetry can be as large as the
25% level near the kinematical region where the and resonances
overlap. By examining a Dalitz plot of this mode and combining a measurement of
the branching ratio for , it is possible to extract the
weak phase, = arg, of the
Kobayashi-Maskawa matrix.Comment: 12 pages, 1 figures. Argument to determine the CKM angle is changed.
Also available via anonymous ftp at ftp://ftp.kek.jp/kek/preprints/TH/TH-54
Development of an atmospheric Cherenkov imaging camera for the CANGAROO-III experiment
A Cherenkov imaging camera for the CANGAROO-III experiment has been developed
for observations of gamma-ray induced air-showers at energies from 10 to
10 eV. The camera consists of 427 pixels, arranged in a hexagonal shape
at 0.17 intervals, each of which is a 3/4-inch diameter photomultiplier
module with a Winston-cone--shaped light guide. The camera was designed to have
a large dynamic range of signal linearity, a wider field of view, and an
improvement in photon collection efficiency compared with the CANGAROO-II
camera. The camera, and a number of the calibration experiments made to test
its performance, are described in detail in this paper.Comment: 25 pages, 29 figures, elsart.cls, to appear in NIM-
IMAGING ATMOSPHERIC CHERENKOV TELESCOPE
The principle of Air Čherenkov techniques used to detect very high-energy astronomical gamma-rays is presented.The CANGAROO experiment in the southern hemisphere as well as other experiments in the world are introduced. The results of past and present experiments are briefly reviewed and also future prospects of this technique are mentioned.