C. Pruneau

Development of large linear silicon drift detectors for the STAR experiment at RHIC

Abstract Large area linear Silicon Drift Detectors (SDD) are being developed for high energy and relativistic heavy ion collider experiments. SDDs have been proposed for the inner tracking detector in the STAR experiment at the BNL relativistic heavy ion collider to become operational in 1999. The Silicon Vertex Tracker (SVT) will consist of a three layer barrel structure composed of 216 individual detectors, each 6.3 × 6.3 cm 2 . Prototypes, including one-way drift detectors (4.5 × 4.5 cm 2 ) and bi-directional drift detectors (6 × 6 cm 2 ) have been manufactured,and their properties have been studied. Design considerations, as well as test results, are presented in this article. Recent work has focused on minimizing the inactive guard structure area in order to optimize tracking efficiency. Particular attention is given to discussion of parameters that are sensitive to the reduced guard structure area, such as leakage current, maximum voltage and drift non-linearities.

Measurements of light nuclei production in 11.5a GeV/c Au+Pb heavy-ion collisions

We report on measurements by the E864 experiment at the BNL-AGS of the yields of light nuclei in collisions of Au(197) with beam momentum of 11.5 A GeV/c on targets of Pb(208) and Pt(197). The yields are reported for nuclei with baryon number A=1 up to A=7, and typically cover a rapidity range from y(cm) to y(cm)+1 and a transverse momentum range of approximately 0.1<p(T)/A<0.5 GeV/c. We calculate coalescence scale factors B(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.

Evidence for expansion of a hot fireball from two-pion correlations for Si + Pb collisions at AGS energy

Abstract The two-pion correlation function has been measured for charged pions produced in central 14.6 A GeV/ c Si + Pb collisions at the AGS. Data for like-sign pions show a clear quantum interference effect as expected for identical bosons. The experimental correlation function agrees well with that obtained for events generated by a cascade code (RQMD). The present data are consistent with a time-averaged rms freeze-out radius of 8.3 fm and a mean duration of pion emission of 9 fm/ c . The system has expanded considerably before freeze-out.

Silicon drift detectors for the STAR/SVT experiment at RHIC

Large area linear Silicon Drift Detectors (SDD) were developed to be used in the Silicon Vertex Tracker (SVT) of the STAR experiment at the BNL relativistic heavy ion collider (RHIC). The SDD is in its final design and has been submitted for large scale production. Test results show that the detector exhibits excellent position resolution and low noise. A special characterization procedure was developed to test detector wafers in order to select good detectors for the SVT. Recently, 15 STAR/SVT SDDs were assembled as a tracking device in a BNL-AGS heavy ion experiment (E896). It is the first tracking application of these detectors and their corresponding front-end electronics in an experimental environment. Preliminary results indicating good detector performance are shown and discussed in this paper.

Antideuteron yield at the AGS and coalescence implications

We present Experiment 864s measurement of invariant antideuteron yields in 11.5A GeV/c Au + Pt collisions. The analysis includes 250 million triggers representing 14 billion 10% central interactions sampled for events with high mass candidates. We find (1/2 pi pt) d^(2)N/dydpt = 3.5 +/- 1.5 (stat.) +0.9,-0.5 (sys.) x 10^(-8) GeV^(-2)c^(2) for 1.8=0.35 GeV/c (y(cm)=1.6) and 3.7 +/- 2.7 (stat.) +1.4,-1.5 (sys.) x 10^(-8) GeV^(-2)c^(2) for 1.4=0.26 GeV/c, and a coalescence parameter B2-bar of 4.1 +/- 2.9 (stat.) +2.3,-2.4 (sys.) x 10^(-3) GeV^(2)c^(-3). Implications for the coalescence model and antimatter annihilation are discussed.

Directed flow of light nuclei in Au + Au collisions at 10.8A GeV/c

Directed flow of deuterons, tritons,

Mass dependence of light-nucleus production in ultrarelativistic heavy-ion collisions

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Search for strange quark matter produced in relativistic heavy ion collisions

He, and

Antiproton production and antideuteron production limits in relativistic heavy ion collisions

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Two-proton correlations from 14.6A GeV/c Si+Pb and 11.5A GeV/c Au+Au central collisions

He is studied in Au+Au collisions at a beam momentum of about 10.8