Deeply virtual exclusive processes offer a unique opportunity to study the internal structure of the nucleon and nuclei. The goal of this work is to extract the beam-spin asymmetry in deeply virtual coherent neutral pion electroproduction, e4He → e′4He′π0, using the CLAS detector in the experimental Hall B at Thomas Jefferson National Accelerator Facility. The data were collected in 2009 with a 6 GeV longitudinally polarized electron beam impinging on a 30 cm long, 6 atm Helium-4 gaseous target. In order to ensure that the process is coherent, a new Radial Time Projection Chamber was used to detect and identify low energy recoil α-particles. The Beam Spin Asymmetry in the coherent deep exclusive regime was measured at Q2 = 1.50 GeV2, XB = 0.18 and −t = 0.14 GeV2. The measured asymmetry has an amplitude of 10%±5% and has the opposite sign compared the asymmetry measured for π0 production on the proton.
","abstract_html":"<p>Deeply virtual exclusive processes offer a unique opportunity to study the internal structure of the nucleon and nuclei. The goal of this work is to extract the beam-spin asymmetry in deeply virtual coherent neutral pion electroproduction, <em>e</em><sup>4</sup>He → <em>e′</em><sup>4</sup>He′π<sup>0</sup>, using the CLAS detector in the experimental Hall B at Thomas Jefferson National Accelerator Facility. The data were collected in 2009 with a 6 GeV longitudinally polarized electron beam impinging on a 30 cm long, 6 atm Helium-4 gaseous target. In order to ensure that the process is coherent, a new Radial Time Projection Chamber was used to detect and identify low energy recoil <em>α</em>-particles. The Beam Spin Asymmetry in the coherent deep exclusive regime was measured at <em>Q</em><sup>2</sup> = 1.50 GeV<sup>2,</sup> X<em>B</em> = 0.18 and −t = 0.14 GeV<sup>2</sup>. The measured asymmetry has an amplitude of 10%±5% and has the opposite sign compared the asymmetry measured for π<sup>0</sup> production on the proton.</p>","abstract_has_math":false,"creators":["Torayev, Bayram"],"institution":null,"degree_name":"Doctor of Philosophy (PhD)","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Stephen Bueltmann","Sabastian Kuhn","Rocco Schiavilla","Alex Godunov","Jennifer Poutsma"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-10-01T07:00:00Z","date_published":"2016-10-01T07:00:00Z","updated_at":"2026-07-24T03:34:02Z","subjects":["Electroproduction","Nucleon","Nuclei","Polarized electron beam","Radical time projection chamber","Nuclear","Physics"],"languages":[],"rights":["In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
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"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["9781369571509","https://digitalcommons.odu.edu/physics_etds/6"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Deeply virtual exclusive processes offer a unique opportunity to study the internal structure of the nucleon and nuclei. The goal of this work is to extract the beam-spin asymmetry in deeply virtual coherent neutral pion electroproduction, e4He → e′4He′π0, using the CLAS detector in the experimental Hall B at Thomas Jefferson National Accelerator Facility. The data were collected in 2009 with a 6 GeV longitudinally polarized electron beam impinging on a 30 cm long, 6 atm Helium-4 gaseous target. In order to ensure that the process is coherent, a new Radial Time Projection Chamber was used to detect and identify low energy recoil α-particles. The Beam Spin Asymmetry in the coherent deep exclusive regime was measured at Q2 = 1.50 GeV2, XB = 0.18 and −t = 0.14 GeV2. The measured asymmetry has an amplitude of 10%±5% and has the opposite sign compared the asymmetry measured for π0 production on the proton.
"]},{"key":"dc:title","label":"Title","values":["Electroproduction of Neutral Pion Off Helium-4"]}]}],"canonical_facts":{"dc:contributor":["Stephen Bueltmann","Sabastian Kuhn","Rocco Schiavilla","Alex Godunov","Jennifer Poutsma"],"dc:creator":["Torayev, Bayram"],"dc:date.available":["2017-02-17T08:00:00Z"],"dc:description.abstract":["Deeply virtual exclusive processes offer a unique opportunity to study the internal structure of the nucleon and nuclei. The goal of this work is to extract the beam-spin asymmetry in deeply virtual coherent neutral pion electroproduction, e4He → e′4He′π0, using the CLAS detector in the experimental Hall B at Thomas Jefferson National Accelerator Facility. The data were collected in 2009 with a 6 GeV longitudinally polarized electron beam impinging on a 30 cm long, 6 atm Helium-4 gaseous target. In order to ensure that the process is coherent, a new Radial Time Projection Chamber was used to detect and identify low energy recoil α-particles. The Beam Spin Asymmetry in the coherent deep exclusive regime was measured at Q2 = 1.50 GeV2, XB = 0.18 and −t = 0.14 GeV2. The measured asymmetry has an amplitude of 10%±5% and has the opposite sign compared the asymmetry measured for π0 production on the proton.
"],"dc:identifier":["9781369571509","https://digitalcommons.odu.edu/physics_etds/6"],"dc:rights":["In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
"],"dc:subject":["Electroproduction","Nucleon","Nuclei","Polarized electron beam","Radical time projection chamber","Nuclear","Physics"],"dc:title":["Electroproduction of Neutral Pion Off Helium-4"],"thesis:degree_discipline":["Physics"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-24T03:34:02Z"}