Cross Section Measurement of Exclusive ϕ-Meson Electroproduction off the Proton at CLAS12

This analysis studies the exclusive ϕ meson electroproduction process ep → e′p′ϕ at CLAS12 in the kinematic region 0.39 ≤ Q² ≤ 8.38 GeV², 1.97 ≤ W ≤ 4.03 GeV, and 0.17 ≤ −t ≤ 7.26GeV². Cross section σ(Q²,W) and differential cross section dσ/dt (Q²,W,t) measurements are reported. The scaling of the overall cross section was determined to be 1/Q⁶˙⁴⁷⁺⁻⁰˙⁹⁷, which is consistent with the Generalized Parton Distribution (GPD) prediction of 1/Q⁶. The ratios of the longitudinal and transverse cross sections, R = σL / σT , are extracted from the angular decay distributions for four values of Q² and are found to be consistent with the GPD scaling prediction. The mean-square gluonic radius of the proton ⟨b²⟩ subscript g is extracted from the t-dependence of the differential cross sections dσ / dt in the kinematic region 0.12 ≤ x subscript B ≤ 0.39, the first such measurement in the valence regime.

Name thesis:degree_name

Doctoral

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Physics

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2024

Author dc:creator

• Moran, Patrick

Advisor dc:contributor.advisor

• Milner, Richard

Statement dc:rights

• In Copyright - Educational Use Permitted
• Copyright retained by author(s)

Licence dc:rights.uri

• https://rightsstatements.org/page/InC-EDU/1.0/

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/157071

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/157071