The PP2PP Experiment at RHIC

TL;DR

The PP2PP experiment at RHIC investigates proton-proton elastic scattering across a range of energies and momentum transfers, utilizing polarized beams to explore spin effects and scattering amplitude characteristics.

Contribution

This work introduces systematic measurements of spin-dependent observables and the energy dependence of scattering features at RHIC, advancing understanding of proton spin structure.

Findings

Measurement of energy dependence of total and elastic cross sections

Observation of the dip structure in differential cross section

Mapping of spin-dependent observables and proton helicity amplitudes

Abstract

The PP2PP experiment is devoted to the proton-proton elastic scattering measurement at the Relativistic Heavy Ion Collider at the centre-of-mass energies between 50 and 500 GeV and the four-momentum transfer $0.0004 \leq |t| \leq 1.3$ Gev$^2$. 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 the imaginary part of the forward scattering amplitude, and the nuclear slope parameter will be studied. In the medium $|t|$ region ($|t| \leq 1.3$ Gev$^2$) 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 function of the of 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.