Average charged multiplicities have been measured separately in
b,
c and light quark (
u,
d,
s) events from
Z
0 decays measured in the SLD experiment. Impact parameters of charged tracks were used to ...select enriched samples of
b and light quark events, and reconstructed charmed mesons were used to select
c quark events. We measured the charged multiplicities:
n
uds = 20.21 ± 0.10(
stat.) ± 0.22(
syst.)
,
n
c = 21.28 ± 0.46(
stat.)
−0.36
+0.41
syst.)
and
n
b = 23.14 ± 0.10(
stat.)
−0.37
+0.38(
syst.)
, from which we derived the differences between the total average charged multiplicities of
c or
b quark events and light quark events:
Δ
n
c = 1.07 ± 0.47(
stat.)
−0.30
+0.36(
syst.)
and
Δ
n
b = 2.93 ± 0.14(
stat.)
−0.29
+0.30(
syst.)
. 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.
Obtaining physics results from the SLD CRID Abe, K; Antilogus, P; Aston, D ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/1996, Letnik:
371, Številka:
1
Journal Article
Recenzirano
Odprti dostop
We describe the likelihood ratio method used for particle identification in the SLD CRID, which allows the use of the entire momentum range covered by the liquid and gas radiators, including the ...threshold regions. Its application to two preliminary physics analyses is also described.
Operational status and performance of the SLD CRID Abe, K; Antilogus, P; Aston, D ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/1996, Letnik:
371, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The operation and performance of the SLD CRID achieved during the recently completed 1994–1995 run of the SLC will be discussed. Stable operation of liquid (C
6F
14) and gas (85% C
5F
12 and 15% N
2) ...radiators with good UV transparency has been achieved. Our expectations for the future SLD physics program will also be briefly discussed.
Kawasaki disease is recognized as the most common cause of acquired heart disease in children in the developed world. Clinical, epidemiologic, and pathologic evidence supports an infectious agent, ...likely entering through the lung. Pathologic studies proposing an acute coronary arteritis followed by healing fail to account for the complex vasculopathy and clinical course.
Specimens from 32 autopsies, 8 cardiac transplants, and an excised coronary aneurysm were studied by light (n=41) and transmission electron microscopy (n=7). Three characteristic vasculopathic processes were identified in coronary (CA) and non-coronary arteries: acute self-limited necrotizing arteritis (NA), subacute/chronic (SA/C) vasculitis, and luminal myofibroblastic proliferation (LMP). NA is a synchronous neutrophilic process of the endothelium, beginning and ending within the first two weeks of fever onset, and progressively destroying the wall into the adventitia causing saccular aneurysms, which can thrombose or rupture. SA/C vasculitis is an asynchronous process that can commence within the first two weeks onward, starting in the adventitia/perivascular tissue and variably inflaming/damaging the wall during progression to the lumen. Besides fusiform and saccular aneurysms that can thrombose, SA/C vasculitis likely causes the transition of medial and adventitial smooth muscle cells (SMC) into classic myofibroblasts, which combined with their matrix products and inflammation create progressive stenosing luminal lesions (SA/C-LMP). Remote LMP apparently results from circulating factors. Veins, pulmonary arteries, and aorta can develop subclinical SA/C vasculitis and SA/C-LMP, but not NA. The earliest death (day 10) had both CA SA/C vasculitis and SA/C-LMP, and an "eosinophilic-type" myocarditis.
NA is the only self-limiting process of the three, is responsible for the earliest morbidity/mortality, and is consistent with acute viral infection. SA/C vasculitis can begin as early as NA, but can occur/persist for months to years; LMP causes progressive arterial stenosis and thrombosis and is composed of unique SMC-derived pathologic myofibroblasts.
Operational experience with the SLD CRID at the SLC Abe, K; Aston, D; Baird, K ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/1996, Letnik:
379, Številka:
3
Journal Article
Recenzirano
Odprti dostop
We highlight some problems encountered and lessons learned in obtaining stable operation of the SLD CRID for the past four years. During the 1994–1995 run of the SLC, we achieved stable operation of ...liquid (C
6F
14) and gas (
85% C
5F
12
15% N
2
) radiators with good UV transparency, and we regularly operate the TPCs with excellent drift lifetimes and good single photo-electron detection efficiency.
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