EXPECTED TRIGGER RATES OF HIGH PT JETS AND DIRECT PHOTONS IN THE STAR EMC. (open access)

EXPECTED TRIGGER RATES OF HIGH PT JETS AND DIRECT PHOTONS IN THE STAR EMC.

The STAR experiment at RHIC is a large acceptance detector. The electromagnetic calorimeter (EMC) will provide a sensitive trigger to study high p{sub t} jets and hard photons in AuAu, pp, and pAu collisions. The capability for the EMC to trigger on jets and direct photons was studied for trigger level 0. Trigger efficiencies and expected process rates were obtained for pp reactions. Results from pp interactions will be essential to the interpretation of AuAu results as well as for the spin physics program. These studies were performed with the standard STAR software chain which includes GEANT and EMC simulations. The HIJING event generator was used to provide input for the simulations.
Date: March 21, 1999
Creator: BELT-TONJES,M. FOR THE STAR COLLABORATION
System: The UNT Digital Library
Flash Vacuum Pyrolysis of Lignin Model Compounds: Reaction Pathways of Aromatic Methoxy Groups (open access)

Flash Vacuum Pyrolysis of Lignin Model Compounds: Reaction Pathways of Aromatic Methoxy Groups

Currently, there is interest in utilizing lignin, a major constituent of biomass, as a renewable source of chemicals and fuels. High yields of liquid products can be obtained from the flash or fast pyrolysis of biomass, but the reaction pathways that lead to product formation are not understood. To provide insight into the primary reaction pathways under process relevant conditions, we are investigating the flash vacuum pyrolysis (FVP) of lignin model compounds at 500 C. This presentation will focus on the FVP of {beta}-ether linkages containing aromatic methoxy groups and the reaction pathways of methoxy-substituted phenoxy radicals.
Date: March 21, 1999
Creator: Britt, P. F.; Buchanan, A. C., III & Martineau, D. R.
System: The UNT Digital Library
THE YEAR-ONE PHYSICS CAPABILITIES OF STAR. (open access)

THE YEAR-ONE PHYSICS CAPABILITIES OF STAR.

When the Relativistic Heavy Ion Collider (RHIC) at BNL begins operation in the Fall of 1999, heavy ions will be accelerated in collider mode for the first time, and a new energy regime will be entered for Heavy Ion Physics. The Solenoidal Tracker At RHIC (STAR) detector has a near 4{pi} coverage and is dedicated to taking hadronic measurements. A large volume Time Projection Chamber placed in a solenoidal magnet at 0.5T is used to track and identify the many thousands of produced particles. STAR will measure many observables simultaneously on an event-by-event basis to study signatures of a possible QGP phase transition and the space-time evolution of the collision process. The goal is to obtain a fundamental understanding of the microscopic structure of hadronic interactions, at the level of quarks and gluons, at high energy densities. This paper outlines the physics STAR intends to study during the first year of operation.
Date: March 21, 1999
Creator: CAINES,H. FOR THE STAR COLLABORATION
System: The UNT Digital Library
Nuclear Coulomb Field Effects in Two-Pion Bose-Einstein Correlations (open access)

Nuclear Coulomb Field Effects in Two-Pion Bose-Einstein Correlations

Differences are investigated in pion source sizes derived using {pi}{sup +}{pi}{sup +} and {pi}{sup -}{pi}{sup -} pairs in the large statistics data set collected with the E866 Forward Spectrometer for central Au+Au collisions at 11.6 A. {center_dot} GeV/c in AGS Experiment E866. These differences in source radii are interpreted using a simple classical description for the Coulomb and the transverse-momentum (p{sub T}) dependent source radius parameters. An estimated effective net charge responsible for the distortion is considerably smaller than the expected total projectile participant protons, which suggests that the system undergoes a rapid expansion in the longitudinal direction before freezeout. This picture is consistent with the results derived from the {pi}{sup -}/{pi}{sup +} singles yield ratios for the same reactions.
Date: March 21, 1999
Creator: Lee, J. H. & Chasman, C.
System: The UNT Digital Library
HIGH PT PHYSICS WITH THE STAR EXPERIMENT AT RHIC. (open access)

HIGH PT PHYSICS WITH THE STAR EXPERIMENT AT RHIC.

The STAR experiment at RHIC is a TPC-based, general purpose detector designed to obtain charged particle spectra, with an emphasis on hadrons over a large phase space. An electromagnetic calorimeter provides measurement of e's, {gamma}'s, {pi}{sup 0}'s and jets. Data-taking with Au + Au collisions at {radical}5 = 200 GeV/c{sup 2} begins in Fall 1999. The STAR experiment's investigation of techniques and signals using hard probes to study the high energy-density matter at RHIC and to search for quark-gluon plasma formation will be described.
Date: March 21, 1999
Creator: TURNER,K. FOR THE STAR COLLABORATION
System: The UNT Digital Library