32 research outputs found
WA92: a fixed target experiment to trigger on and identify beauty particle decays
We describe the detectors and trigger system used in the CERN WA92 experiment. The experiment was designed to study the production and decay of beauty particles from 350 GeV/ interactions in copper and tungsten targets. Charged particle tracking is performed using the Omega spectrometer. Silicon microstrip detectors are used to provide precise tracking information in the region of the production and the decay of heavy-flavoured particles and to trigger on the resulting high impact parameter tracks. The precision of vertex reconstruction corresponds to of the mean B-decay proper lifetime. Lepton and high transverse momentum hadron signals are also used in the trigger, which accepts 29\% of B-decays and rejects 98\% of non-beauty interactions
Measurement of the beauty production cross-section in 350 GeV/c -Cu interactions
Using a sample of triggered events, produced in --Cu interactions at 350~GeV, we have identified 26 beauty events. The estimated background in this sample is events. From these data, assuming a linear A-dependence, we measure a beauty production cross-section integrated over all of nb/N
Association between Ramadan Fasting and cerebrovascular diseases
Background and objective: Cerebrovascular diseases are attacks of sudden neurological deficits (motor, sensory or cerebellar). There are a lot of risk factors for stroke like age, diabetes, hypertension, smoking, hyperlipidemia, cardiac diseases and others. This study aimed to show if there is increasing rate of cerebrovascular events during Ramadan in relation to fasting in our city during the summer season.
Methods: This case-control study was carried out in Rizgary Teaching Hospital, Erbil- Iraq from 1st of August to 30th of August 2011. Patients were included in this study if they were middle aged and elderly patients having clinical and radiological features of stroke, another group of in-patients was selected as a control group. Chi square test and logistic regression analyses were used to show the association between stroke and fasting.
Results: A sample of 60 patients and 60 control cases were included in this study. Fasting was significant risk factor for stroke in our studied sample, 66.7% of the cases were fasting compared with 40% of the control group (P = 0.03). Hyperlipidemia and history of ischemic heart disease found also to be associated with stroke (P = 0.017 and 0.011, respectively). Logistic regression analysis showed that only fasting and hypercholesterolemia were independent risks factors in causing stroke in our studied sample.
Conclusion: In Erbil, where the summer is too hot and the daytime (fasting hours) is long, fasting during Ramadan was found to be an independent risk factor for stroke, and specifically ischemic stroke
A measurement of the form-factor ratios in the decay
The form-factor ratios in the decay have been measured using a sample of 763 events produced in the WA92 fixed-target experiment. \\ The value s obtained are and the corresponding ratio of longitudinal to transverse polarisation is \rm{\Gamma_L/\Gamma_T = 1.09 \pm 0.10 \p m 0.02}
A measurement of the form-factor ratios in the decay D+->(K)over-bar(*0)mu(+)nu(mu)
The form-factor ratios in the decay D+ --> (K) over bar*(0)mu(+)upsilon(mu) have been measured using a sample of 763 events produced in the WA92 fixed-target experiment. The values obtained are R-V = 1.45 +/- 0.23 +/- 0.07, R-2 = 1.00 +/- 0.15 +/- 0.03 and the corresponding ratio of longitudinal to transverse polarisation is Gamma(L)/Gamma(T) = 1.09 +/- 0.10 +/- 0.02
A measurement of the form-factor ratios in the decay D + →K * 0 µ + ν µ The BEATRICE Collaboration
Abstract. The form-factor ratios in the decay D + →K * 0 µ + νµ have been measured using a sample of 763 events produced in the WA92 fixed-target experiment. The values obtained are RV = 1.45 ± 0.23 ± 0.07, R2 = 1.00 ± 0.15 ± 0.03 and the corresponding ratio of longitudinal to transverse polarisation is ΓL/ΓT = 1.09 ± 0.10 ± 0.02
A study of kinematical correlations between charmed particles produced in pi-Cu interactions at root s=26 GeV
A sample of 475 events, in which two charmed-particle decays are observed, is analyzed to determine distributions of two-particle kinematic variables. One charmed particle with x(F) > 0 is fully reconstructed and the other is at least partially recontructed. The distributions of Delta phi and p(T)(2) are compared with a next-to-leading order QCD calculation