We report new precision measurements of the lifetimes of the Lambda(+)(c) and D0 from SELEX, the charm hadroproduction experiment at Fermilab. Based upon 1630 Lambda(+)(c) and 10 210 D0 decays we ...observe lifetimes of tauLambda(+)(c) = 198.1+/-7.0+/-5.6 fs and tauD0 = 407.9+/-6.0+/-4.3 fs.
Total cross sections for
Σ
− and
π
− on beryllium, carbon, polyethylene and copper as well as total cross sections for protons on beryllium and carbon have been measured in a broad momentum range ...around
600
GeV/c
. These measurements were performed with a transmission technique in the SELEX hyperon-beam experiment at Fermilab. We report on results obtained for hadron–nucleus cross sections and on results for
σ
tot(
Σ
−N) and
σ
tot(
π
−N) , which were deduced from nuclear cross sections.
Photoproduction at HERA is studied in
ep collisions, with the ZEUS detector, for
γp centre-of-mass energies ranging from 130–270 GeV. A sample of events with two high-
p
T
jets (
p
T
> 6 GeV,
η < ...1.6) and a third cluster in the approximate direction of the electron beam is isolated using a clustering algorithm. These events are mostly due to resolved photoproduction. The third cluster is identified as the photon remnant. Its properties, such as the transverse and longitudinal energy flows around the axis of the cluster, are consistent with those commonly attributed to jets, and in particular with those found for the two jets in these events. The mean value of the photon remnant
p
T
with respect to the beam axis is measured to be 2.1 ± 0.2 GeV, which demonstrates substantial mean transverse momenta for the photon remnant.
We report the first observation of the Cabibbo-suppressed charm baryon decay Xi(+)(c)-->pK(-)pi(+). We observe 150+/-22+/-5 events for the signal. The data were accumulated using the SELEX ...spectrometer during the 1996-1997 fixed target run at Fermilab, chiefly from a 600 GeV/c Sigma(-) beam. The branching fractions of the decay relative to the Cabibbo-favored Xi(+)(c)-->Sigma+K-pi(+) and Xi(+)(c)-->Xi(-)pi(+)pi(+) are measured to be B(Xi(+)(c)-->pK(-)pi(+))/B(Xi(+)(c)-->Sigma+K-pi(+)) = 0.22+/-0. 06+/-0.03 and B(Xi(+)(c)-->pK(-)pi(+))/B(Xi(+)(c)-->Xi(-)pi(+)pi(+)) = 0.20+/-0.04+/-0.02, respectively.
Study of microstrip detectors Gutierrez, P.; Kalbfleisch, G.; Kaplan, D. ...
Conference Record of the 1991 IEEE Nuclear Science Symposium and Medical Imaging Conference,
1991
Conference Proceeding
Single- and double-sided AC-coupled detectors and double-sided DC-coupled detectors read out with the Berkeley SVXD chip are being studied. The authors report on the signal and noise characteristics ...for typical single channels and the channel-to-channel variations in noise, gain, and pedestal values. Because collider detectors encounter tracks at all angles of incidence, the authors studied the response of the prototypes over a wide range of angles to see whether the cluster size and charge sharing properties of the various detectors are different. For angles at approximately 0 degrees , the resolution of the double-sided detector is 4.5 mu m on the ohmic side and 3.5 mu m for the single-sided AC coupled detector. The signal-to-noise ratio for the double-sided detector is 25:1, while for the single-sided detector it is 38:1.< >
PDF
