A ring-imaging Cherenkov counter read out by a 100-channel PMT of active area 10 × 10 cm
2 was operated successfully in a test beam at the BNL AGS with several radiator gases, including the heavy ...fluorocarbon C
4F
10. Ring radii were measured for electrons, muons, pions and kaons over the particle momentum range from 2 to 12 GeV/
c, and a best resolution of
σ
r
r
= 2.3%
was obtained.
Methods used to track a cohort of Grade 6 students through Grades 8 and 11, and costs involved for survey completion in school and by mail for ever and never smokers from the original group are ...detailed. At baseline, 1,598 students in Scarborough, Canada, completed a questionnaire on smoking, drinking, and health, and again in Grade 8 (N=1,543/1,598) and Grade 11 (N=1,454/1,598). In Grades 8 and 11, tracking and administering the questionnaire was more costly per participant when the survey was administered by mail than in school. Average completion costs were highest for Grade 11 students who used tobacco at baseline ($52.44). Students categorized as ever smokers in Grade 6 were harder to locate at each phase of testing, which suggests that this group should be identified at baseline so that closer tracking procedures may be employed between data collection points.
Positive pion and kaon production from Au+Au reactions have been measured as a function of beam energy over the range 2.0–10.7 AGeV. Both the kaon and the pion production cross-sections at ...mid-rapidity are observed to increase steadily with beam kinetic energy. The ratio of K
+ to
π
+ mid-rapidity yields increases from 0.0271±0.0015±0.0014 at 2.0 AGeV to 0.202±0.005±0.010 at 10.7 AGeV and is larger than the K
+/
π
+ ratio from p+p reactions over the same beam energy region. There is no indication of a strong onset of any new production mechanism in heavy-ion reactions in this energy range beyond rescattering of hadrons.
Studies of the heating effect of 8 GeV/c
π
− and antiproton beams incident on a
197Au nucleus have been conducted at Brookhaven AGS accelerator with the Indiana Silicon Sphere 4π detector array. ...Enhanced energy deposition for antiprotons relative to negative pions and protons in this energy regime is observed. The results are consistent with predictions of an intranuclear cascade code.
We present the first measurement of the pseudorapidity density of primary charged particles in Au+Au collisions at root squares(NN) = 200 GeV. For the 6% most central collisions, we obtain ...dN(ch)/d(eta)/(/eta/<1) = 650+/-35(syst). Compared to collisions at root squares(NN) = 130 GeV, the highest energy studied previously, an increase by a factor of 1.14+/-0.05 at 90% confidence level, is found. The energy dependence of the pseudorapidity density is discussed in comparison with data from proton-induced collisions and theoretical predictions.
The yield for the multistrange Xi(-) hyperon has been measured in 6A GeV Au+Au collisions via reconstruction of its decay products pi(-) and Lambda, the latter also being reconstructed from its ...daughter tracks of pi(-) and p. The measurement is rather close to the threshold for Xi(-) production and therefore provides an important test of model predictions. The measured yield for Xi(-) and Lambda are compared for several centralities. In central collisions the Xi(-) yield is found to be in excellent agreement with statistical and transport model predictions, suggesting that multistrange hadron production approaches chemical equilibrium in high baryon density nuclear matter.
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