Development of a Monte Carlo Generator for the Bethe Heitler Process

The study of the nucleon structure in terms of Generalized Parton Distributions via Deeply Virtual Compton Scattering has been the focus of an extensive experimental program at many laboratories such as Jefferson Lab. When measuring DVCS, the Bethe Heitler process dominates the cross section and contributes to the spin asymmetries by interference, therefore a full understanding of the Bethe Heitler process is essential for DVCS measurements. Of particular interest is the calculation of Bethe Heitler for the deuteron. For this purpose I have developed a Python program to calculate Bethe Heitler of the deuteron for all polarizations using the formalism in [2] and new calculations [1]. I will present the dependence of the Bethe Heitler cross section in terms of the four independent variables - the four-momentum squared of the virtual photon Q², the four-momentum squared that is transferred from the initial to the final deuteron (t), x Bjorken (x_Bj), and the angle between the leptonic and hadronic planes (Φ). In addition, I will discuss the phase space and kinematic limits for this process. Ultimately, this work will be used to develop a Monte Carlo generator to be used with the CLAS12 simulation to study coherent DVCS acceptance.

References:

[1] S. Liuti, Private communication.

[2] B. Kriesten, S. Liuti, L. Calero-Diaz, D. Keller, A. Meyer, G. R. Goldsteinand J. Osvaldo Gonzalez-Hernandez, Phys. Rev. D101(2020) no.5, 054021