STUDY OF BEAM SPIN ASYMMETRY IN EXCLUSIVE Π° PRODUCTION

Journal Article · Mon Jan 01 00:00:00 EST 2007 · Journal of Undergraduate Research

OSTI ID:1051821

Howley, I; Avagyan, H

Describing and understanding atomic nuclei is a puzzle that has intrigued scientists for decades. Approximately ten years ago, a description of nucleon structure, referred to as Generalized Parton Distribution (GPD), was introduced. GPDs are a way of describing scattering and production processes in a single framework. Deeply Virtual Compton Scattering (DVCS) is a process that scatters a photon from a proton and detects a scattered electron, a proton, and one photon in the fi nal state. From DVCS, GPDs can be extracted in order to lead us to a more complete picture of nucleon structure. The focus of this study is to understand the beam spin asymmetry (BSA) of the neutral π° meson, a main source of background during the DVCS process. To calculate the BSA, the number of π° events with positive helicity (spin) and negative helicity were counted by integrating histograms with Gaussians fi ts. It is shown that there is a signifi cant non-zero BSA in production of exclusive π°, namely 0.0655±0.0022. In the analysis of previous experiments, the BSA of π° was assumed to be zero and therefore ignored. Now, future analyses of DVCS data may incorporate this evidence of BSA. A deeper understanding of background processes (π°) in the DVCS will allow precision measurements of GPDs, providing new insight concerning the structure of nucleons.

• Research Organization: DOESC (USDOE Office of Science (SC) (United States))
• Sponsoring Organization: USDOE Office of Science (SC)
• OSTI ID: 1051821
• Journal Information: Journal of Undergraduate Research, Vol. 7
• Country of Publication: United States
• Language: English