{"id":{"repo_id":"mit","oai_identifier":"oai:dspace.mit.edu:1721.1/35051"},"canonical_url":"https://search.dev.ndltd.org/etd/mit/oai:dspace.mit.edu:1721.1/35051","repository":{"repo_id":"mit","name":"MIT","base_url":"https://dspace.mit.edu/oai/request"},"display":{"title":"Study of flavor tagging with semi-exclusive reconstruction of b [right arrow] D(sigma)X decays","abstract":"The BaBar experiment measures CP violation in the B meson system by analyzing the decays of B⁰B̄⁰ pairs in which one of the mesons decays into a CP eigenstate. By measuring the decay time distribution separately for B⁰ and B̄⁰ decays the CP violating asymmetry and sin 2[beta] can be measured. In order to measure the decay time distribution for the B⁰ and B̄⁰ decays, it is necessary to identify the flavor, or tag, of the second B meson. The flavor of the B meson is identified by an algorithm which analyzes physical processes which carry flavor information from its decay. Analyzing new physical processes could potentially improve the efficiency of the tagging algorithm. I tested the effect of adding subtaggers which estimated the flavor of the tag B based on the flavor or the charge of its D⁰ or Ds daughters. However due to the low yields and high backgrounds of reconstructed D⁰ and Ds candidates, these subtaggers were not effective at making a net contribution to the tagging process.","abstract_html":"The BaBar experiment measures CP violation in the B meson system by analyzing the decays of B⁰B̄⁰ pairs in which one of the mesons decays into a CP eigenstate. By measuring the decay time distribution separately for B⁰ and B̄⁰ decays the CP violating asymmetry and sin 2[beta] can be measured. In order to measure the decay time distribution for the B⁰ and B̄⁰ decays, it is necessary to identify the flavor, or tag, of the second B meson. The flavor of the B meson is identified by an algorithm which analyzes physical processes which carry flavor information from its decay. Analyzing new physical processes could potentially improve the efficiency of the tagging algorithm. I tested the effect of adding subtaggers which estimated the flavor of the tag B based on the flavor or the charge of its D⁰ or Ds daughters. However due to the low yields and high backgrounds of reconstructed D⁰ and Ds candidates, these subtaggers were not effective at making a net contribution to the tagging process.","abstract_has_math":false,"creators":["Ptacek, Elizabeth S. (Elizabeth Sara)"],"institution":"Massachusetts Institute of Technology","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Massachusetts Institute of Technology. Dept. of Physics.","school":null,"contributors":[],"advisors":["Gabriella Sciolla."],"committee_chairs":[],"committee_members":[],"year":2005,"date_issued":"2005","date_published":"2005","updated_at":"2026-07-22T22:21:13Z","subjects":["Physics."],"languages":["eng"],"rights":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."],"rights_urls":["http://dspace.mit.edu/handle/1721.1/7582"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1721.1/35051","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Gabriella Sciolla."]},{"key":"dc:contributor.department","label":"Department","values":["Massachusetts Institute of Technology. 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By measuring the decay time distribution separately for B⁰ and B̄⁰ decays the CP violating asymmetry and sin 2[beta] can be measured. In order to measure the decay time distribution for the B⁰ and B̄⁰ decays, it is necessary to identify the flavor, or tag, of the second B meson. The flavor of the B meson is identified by an algorithm which analyzes physical processes which carry flavor information from its decay. Analyzing new physical processes could potentially improve the efficiency of the tagging algorithm. I tested the effect of adding subtaggers which estimated the flavor of the tag B based on the flavor or the charge of its D⁰ or Ds daughters. However due to the low yields and high backgrounds of reconstructed D⁰ and Ds candidates, these subtaggers were not effective at making a net contribution to the tagging process."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["S.B."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Study of flavor tagging with semi-exclusive reconstruction of b [right arrow] D(sigma)X decays"]}]}],"canonical_facts":{"dc:contributor.advisor":["Gabriella Sciolla."],"dc:contributor.department":["Massachusetts Institute of Technology. Dept. of Physics."],"dc:contributor.other":["Massachusetts Institute of Technology. Dept. of Physics."],"dc:creator":["Ptacek, Elizabeth S. (Elizabeth Sara)"],"dc:date.accessioned":["2006-12-18T19:59:42Z"],"dc:date.available":["2006-12-18T19:59:42Z"],"dc:date.issued":["2005"],"dc:description":["Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2005.","In title on t.p., \"[right arrow]\" is a symbol and \"(sigma)\" is the lower case Greek letter, subscript.","Includes bibliographical references (p. 46-47)."],"dc:description.abstract":["The BaBar experiment measures CP violation in the B meson system by analyzing the decays of B⁰B̄⁰ pairs in which one of the mesons decays into a CP eigenstate. By measuring the decay time distribution separately for B⁰ and B̄⁰ decays the CP violating asymmetry and sin 2[beta] can be measured. In order to measure the decay time distribution for the B⁰ and B̄⁰ decays, it is necessary to identify the flavor, or tag, of the second B meson. The flavor of the B meson is identified by an algorithm which analyzes physical processes which carry flavor information from its decay. Analyzing new physical processes could potentially improve the efficiency of the tagging algorithm. I tested the effect of adding subtaggers which estimated the flavor of the tag B based on the flavor or the charge of its D⁰ or Ds daughters. However due to the low yields and high backgrounds of reconstructed D⁰ and Ds candidates, these subtaggers were not effective at making a net contribution to the tagging process."],"dc:description.degree":["S.B."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/1721.1/35051"],"dc:language.iso":["eng"],"dc:publisher":["Massachusetts Institute of Technology"],"dc:rights":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."],"dc:rights.uri":["http://dspace.mit.edu/handle/1721.1/7582"],"dc:subject":["Physics."],"dc:title":["Study of flavor tagging with semi-exclusive reconstruction of b [right arrow] D(sigma)X decays"],"dc:type":["Thesis"]},"updated_at":"2026-07-22T22:21:13Z"}