The PP2PP Experiment at RHIC

The PP2PP experiment is devoted to the proton-proton elastic scattering measurements at the Relativistic Heavy Ion Collider (RHIC) at the center-of-mass energies 50 < √s < 500 GeV and the four-momentum transfer 0.0004 ≤ abs( t) ≤ 1.3 GeV2 . The option of polarized proton beams offers a unique possibility to investigate the spin dependence of the proton elastic scattering in a systematic way. The energy dependence of the total and elastic cross section, the ratio of the real to imaginary part of the forward scattering amplitude, and the nuclear slope parameter will be studied. In the medium abs( t) region (abs( t ) ≤ 1.3 GeV2 ) the energy dependence of the dip structure in the elastic differential cross section will be measured. With polarized beams the measurement of spin dependent observables: the difference of the total cross sections as functions of the initial transverse spin states, the analyzing power and the double spin asymmetries will be used to map the s and t dependence of the proton helicity amplitudes. (author)