2026-09-19T04:29:38Zhttps://dspace.mit.edu/server/oai/requestoai:dspace.mit.edu:1721.1/1202192022-01-13T07:54:07Zcom_1721.1_7582com_1721.1_7581col_1721.1_131024
Jesse Thaler.
Hall, Zachary (Zachary H.)
Massachusetts Institute of Technology. Department of Physics.
Massachusetts Institute of Technology. Department of Physics
2019-02-05T15:58:45Z
2019-02-05T15:58:45Z
2018
2018
http://hdl.handle.net/1721.1/120219
1082867284
Thesis: S.B., Massachusetts Institute of Technology, Department of Physics, 2018.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 41-45).
We introduce soft drop isolation, a new photon isolation criterion inspired by jet substructure techniques. Soft drop isolation is collinear-safe and is equivalent to Frixione isolation at leading order in the small R limit. However, soft drop isolation has the interesting feature of being democratic, meaning that photons can be treated equivalently to hadrons for initial jet clustering. Taking advantage of this democratic property, we define an isolated photon subjet: a photon that is not isolated from its parent jet but is isolated within its parent subjet after soft drop declustering. The kinematics of this isolated photon subjet can be used to expose the QED splitting function, in which a quark radiates a photon, and we verify this behavior using both a parton shower generator and a perturbative calculation in the collinear limit.
by Zachary Hall.
S.B.
45 pages
eng
Massachusetts Institute of Technology
MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.
http://dspace.mit.edu/handle/1721.1/7582
Physics.
Photon isolation and jet substructure
Thesis
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Publication
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