Document Type



Doctor of Philosophy (PhD)



First Advisor's Name

Lei Guo

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

Brian Raue

Second Advisor's Committee Title

Committee Member

Third Advisor's Name

Misak Sargsian

Third Advisor's Committee Title

Committee Member

Fourth Advisor's Name

Julian Edward

Fourth Advisor's Committee Title

Committee Member


Antibaryon Photoproduction, Antiproton, Proton-Antiproton photoproduction

Date of Defense



Antibaryon production has been investigated since the advent of nuclear

physics, largely motivated by the potential for baryon-antibaryon bound states.

Due to the recent availability of high statistics experiments there has been a

renewed interest in how antibaryons are created in photoproduction. The g12

(E04-005) experiment conducted at Thomas Jefferson National Accelerator Fa-

cility used the CEBAF Large Acceptance Spectrometer to provide the world’s

largest dataset for baryon-antibaryon photoproduction on a liquid hydrogen tar-

get. The focus of this work is to investigate the photoproduction mechanism of

γp → ppp ̄ through detailed differential cross section measurements from 3.95

to 5.45 GeV. These first time results as well as the resulting total cross section

measurement are reported. In particular the energy dependence (σ(Eγ)) and the

angular dependence (dσ/dcos(θCM)) have interesting features that have never p ̄

been seen before. On the other hand, the mass distributions (dσ/dM(pp) and dσ/dM(pp ̄) do not show evidence for previously reported narrow resonances. In addition, the first time total cross section mesurement of an antineutron in photoproduction using the reaction γp → ppn ̄π− is reported. The significance and implications of these results will be discussed as well.



Included in

Nuclear Commons



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