Collaborative Research: PP2PP, a Comprehensive Elastic proton-proton Scattering Experiment at RHIC

Suny At Stony Brook, Stony Brook NY

Investigators

Abstract

The award covers graduate student and undergraduate student research with the PP2PP experiment at the Relativistic Heavy Ion Collider at the Brookhaven National Laboratory. The goal of the international PP2PP collaboration is the comprehensive measurement of proton-proton elastic scattering, eventually covering a wide, and unexplored, domain in energy (from 50 to 500 GeV) and momentum transfer (from 0.006 GeV^2 to 1.3 GeV^2) within a single experiment. The first data run with polarized proton beams will take place in the Fall 2001. Two Roman pot detector stations will be used, one in each arm. Two more stations plus central tracking will be added in following years. With the experiment and by comparing with existing antiproton-proton elastic scattering data, the helicity structure of the long-distance pp interaction will be investigated, the exchange mechanisms will be studied and connected to QCD calculations of multi-gluon exchanges. The intriguing dip structure in pp elastic scattering will be accessible with high statistics. At very small momentum transfers PP2PP will measure absolute cross sections and the details of the forward scattering amplitude. Beyond 2003, a special tune of the RHIC machine will allow the lowest accessible momentum transfer to reach into the Coulomb regime. The small scale of the PP2PP experiment makes it ideally suited for participation by undergraduate students in all aspects of construction, data taking, and data analysis.