The results of a measurement of production in Au-Au collisions at 11.6 A GeV/c by Experiment 891 at the Brookhaven AGS are presented. The measurements cover the rapidity region of 2.0 to 3.2 and transverse momenta of 0.0 to 1.4 GeV/c. The results are compared with similar measurements of Si-Si interactions and the predictions of ARC and RQMD models

Eiseman, S.E.

Foley, K.J.

Saulys, A.C.

UNT Digital Library

BNL- 6 3 735 A PRODUCTION IN AU-AU COLLISIONS AT THE AGS A.C. SAULYS for the E891 Collaboration APR 1 8 1997 S. Ahmadd, B.E. Bonnerd, C.S. Chanb, J.M. Clementd, S.V. Efremovd, E. F%tathiadisb, S.E. Eiseman", A. Etkin", K.J. Foley", RW. Hackenburg", M.A. Kramerb, S.J. LindenbaumaIb, R.S. Longacre", W.A. Lovea, J. MarxC, G.S. Mut&erd, E.D. Platnerd, A.C. Saulysa, L.S. S&roederC, H.W. Themannd, K: Zhaob, Y. Zhub " Brookhaven National Laboratory, Upton, N Y  11973, USA OS?I  City  College of New York, N Y  10031, USA Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA Rice University, Houston, TX 77251, USA The results of ameasuremcnt of A productionin Au-Au collisionsat 11.6 A GeV/c by Experiment 891 at the Brookhaven AGS are presented. The measuremats cover the rapidity region of 2.0 to 3.2 and transverse momenta of 0.0 to 1.4 GeV/c. The results are compared with similar measurements of Si - Si interactions and the predictions of ARC and RQMD models. 1 Exper imen ta l  method and results The apparatus foi this experiment is similar to that used in an earlier ex- periment '. It is based on charged track reconstruction in TPC. We used the charged track multiplicity for centrality selection. The trigger cross sec- tion for this data sample was 270 mb. In fig. la we present the A trans- verse mass distributions and in fig. l b  we present the A rapidity distributions with the predictions of the ARC and RQMD models for impact parame- ters 0-4 fermi. We used a global fit to the data points in fig. la of the form A.ezp((a + b - cosh(y- yo))-% + c-  (y- where A is an arbitrary constant and a, b, c are independent of rapidity. We scaled the A production from Si + Si using the AlX:  ratio and the Kf + K- data3 from Au + Au. 2 Conclusions In summary, our measured A rapidity distribution for Au + Au central in- teractions agrees with the scaling of Si + Si measurements and with the predictions of the ARC model. The transverse mass distributions become less steep at mid-rapidity compared to the Si+Si measurements or the predictions of ARC and RQMD models. 1 DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, express or implied, or assumes any legal liabili- ty or responsibility for the accuracy, completeness, or usefulness of any information, appa- ratus, product, or process disdased, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessar- ily state or reflect those of the United States Government or any agency thereof. Figure l a  Figure 1 b Figure 1: a) Transverse mass (m,) distributionsfor A's. Each rapidity rangehas been scaled up by a factor of 10 as shown in the legend on the plot. The solid lines for 2.0 < y(A) < 2.9 are fits to the points and for 2.9 < y(A) < 3.2 the solid line is the result of the global fit desaibedin the text. Errors shown are statistical only. b)F&pidity distribution for A's. The solid curve is the result of scaling Si f Si data as explained in the text. The dashed lines are the ARC predictions and the dotted lines are the RQMD predictions in both figures. Acknowledgments This research was supported by the U.S. Department of Energy and the City University of New York PSC-BHE Research Award Program. We wish to thank the members of the AGS department and the MPS staff for their support during this experiment. We thank D. Kahana for providing us with events from the ARC model. We are grateful to H. Sorge for access to the RQMD code and advice on running it. References 1. S.E. Eiseman, et al., Phys. Lett. B 248, 254 (1990). 2. S.E. Eiseman et al., Phys. Lett. B 297, 44 (1992). 3. F. Vidabaek €or E802 collaboration, Nucl. Phys. A 590, 249c (1995). 4. Y. Pang et al., Phys. Rev. Lett. 68, 2743 (1992); S. Kahana et al., Physics at the AGS with a Relativistic Cascade, in: Heavy-Ion Physics at the AGS (MET, Jan. 1993) p. 263. 5. H. Sorge, Phys. Rev. C 52, 3291 (1995); Nucl. Phys. A 590, 571c (1995). 2 

A production in Au-Au collisions at the AGS

https://digital.library.unt.edu/ark:/67531/metadc683292/m2/1/high_res_d/472895.pdf

A production in Au-Au collisions at the AGS

Abstract

Similar works

Full text

Available Versions

UNT Digital Library