Extraction of Tl' Asymmetry in Neutral Pion Electroproduction near Threshold

Neutral pion photoproduction at threshold provides a good testing ground for Chiral Perturbation Theory. With the completion of new electron accelerators with high duty factor and high intensity twenty years ago, several neutral pion electroproduction experiments near threshold have been conducted. The experimental data on this subject have shown serious discrepancies with the predictions of Chiral Perturbation Theory [15]. However, the current experimental data are not precise enough for conducting a detailed analysis. To test these discrepancies, Jefferson Lab Hall A experiment E04-007 was performed in 2008. This thesis reports the analysis of the data from this experiment. The analysis includes the extraction of the TL ′ asymmetry, and the comparison of this asymmetry to theoretical models. This thesis has three chapters. In the first chapter, a brief history of this field is introduced, followed by a theoretical description of neutral pion electroproduction. The second chapter introduces the experimental setup and the kinematic settings used in the E04-007 experiment. The third chapter presents the analysis of TL ′ asymmetry. This chapter includes two parts, the first part describes the criteria we use to select clean data from the raw data, and the second part introduces the definition of the TL ′ asymmetry at the beginning, followed by the asymmetry calculation from the experimental data. Finally the results are used to compare with the theoretical predictions.

Note: Abstract extracted from PDF text