Probing Quark Dynamics in Semi-Inclusive Charged Pion Electroproduction with CLAS12

This dissertation presents the measurement of electoproduced charged pions multiplicities from data collected in 2018 by the CLAS12 experiment using an unpolarized hydrogen target, as well as beam single spin asymmetry extracted for positively charged pions. These observables are obtained in a 4-dimensional (x, Q^2, z; PT^2) binning, and covering a widekinematic range. The kinematic range for the multiplicity analysis is: Q2 [1;10] (GeV)2, x [0:05;0:7], z [0:2;0:5] and PT2 [0;1:3] (GeV)2. The kinematic range for the beam single spin asymmetry is: Q2 [1;10] (GeV)2, x [0:01;0:8], z [0:3;0:8] and PT [0;1:2] (GeV). These measurements give access to transverse momentum dependent partonic distributionand fragmentation functions (TMDs) which describe the transverse motion of quarks inside of the proton and their hadronization process. The data provide an important input for global fit of world data, and aim at improving the TMDs determination in a kinematic region that is mostly unexplored by other experiments. In the dissertation, the influence of phase space limitations and vector mesons decays on the measured quark’s transverse momentum distribution is discussed. Such effects could explain the transverse momentum distribution observed in our data, and could provide an explanation for the transverse momentum distributions measured by other experiments as well. Results are in good agreement with TMDs global fit extractions, even if the kinematic region of the CLAS12 experiment is at the limit of validity of the current theoretical framework.

Author

• Angelini, Giovanni

Language

• en

Date created

• 2021

Type of Work

• Dissertation

License

• All rights reserved

Rights statement

• In Copyright

GW Unit

• Physics

Degree

• Ph.D.

Advisor

• Rossi, Patrizia
• Briscoe, William J

Committee Member(s)

• Avagyan, Harut
• Strakovsky, Igor

Persistent URL

•  https://scholarspace.library.gwu.edu/etd/2227mq498