We argue that as the atomic number of the target nucleus
A → ∞, the multiplicity of leading particles in hadron-nucleus collisions tends to a finite limit. The limiting multiplicities for various ...particle production are computed for both proton and pion projectiles. Signatures at finite
A are discussed. Data from 100 GeV/
c central hadron-nucleus collisions are analyzed and found to be in qualitative agreement with this picture.
We present Experiment 864's measurement of invariant antideuteron yields in 11.5A GeV/c Au+Pt collisions. The analysis includes 250x10(6) triggers representing 14x10(9) 10% central interactions ...sampled for events with high mass candidates. We find (1/2pip(t))d(2)N/dydp(t) = 3.5+/-1.5(stat)+0.9-0.5(syst)x10(-8) GeV-2 c(2) for 1.8<y<2.2, < p(t)> = 0.35 GeV/c ( y(c.m.) = 1.6) and 3.7+/-2.7(stat)+1.4-1.5(syst)x10(-8) GeV-2 c(2) for 1.4<y<1.8, < p(t)> = 0.26 GeV/c, and a coalescence parameter B2; of 4.1+/-2. 9(stat)+2.3-2.4(syst)x10(-3) GeV2 c(-3). Implications for coalescence and antimatter annihilation are discussed.
Large straw-tube tracking chambers for AGS experiment E864 Armstrong, T.A; Lewis, R.A; Passaneau, J ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/1999, Letnik:
425, Številka:
1
Journal Article
Recenzirano
We have built two very large planar straw tube detectors with 4
mm diameter tubes for AGS experiment E864. This is a Au+Pb collision experiment at 11.5
AGeV/c, designed to search for strangelets and ...other novel forms of matter. A central collision trigger requires tracking chambers to operate in a high multiplicity environment, with as many as 200 hits per event in the first data run, which represented an occupancy of 20%. Each detector consists of three planes of tubes, a vertical
X plane as well as stereo
U and
V planes. Each plane has two close-packed layers of tubes. One detector is 40
cm×200
cm and contains 3×960 tubes, and the other is 80
cm×400
cm and has 3×1920 tubes. The function of the detector is to achieve high mass resolution in tracking charged particles, and it has been successfully used during three data runs at the AGS.
Methods used for the computation of the stopping power of high-atomic-number media to light and heavy nuclear fragments in un-ionized and completely ionized states are reasonably well developed. This ...is not the case for partially ionized states. We propose a method that bridges these two extremes and discuss applications of the method to {alpha} particles and fission fragments in uranium at extreme temperatures and densities.
We report on a search for metastable positively and negatively charged states of strange quark matter in Au+Pb reactions at 11.6 A GeV/
c in experiment E864. We have sampled approximately six billion ...10% most central Au+Pb interactions and have observed no strangelet states (baryon number
A < 100 droplets of strange quark matter). We thus set upper limits on the production of these exotic states at the level of 1–6 × 10
−8per central collision. These limits are the best and most model independent for this colliding system. We discuss the implications of our results on strangelet production mechanisms, and also on the stability question of strange quark matter.
We report on measurements by the E864 experiment at the BNL-AGS of the yields of light nuclei in collisions of {sup 197}Au with beam momentum of 11.5A GeV/c on targets of {sup 208}Pb and {sup 197}Pt. ...The yields are reported for nuclei with baryon number A=1 up to A=7, and typically cover a rapidity range from y{sub c.m.} to y{sub c.m.}+1 and a transverse momentum range of approximately 0.1{<=}p{sub T}/A{<=}0.5 GeV/c. We calculate coalescence scale factors B{sub A} from which we extract model-dependent source dimensions and collective flow velocities. We also examine the dependences of the yields on baryon number, spin, and isospin of the produced nuclei. (c) 2000 The American Physical Society.
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