{"id":{"repo_id":"cambridge","oai_identifier":"oai:www.repository.cam.ac.uk:1810/297741"},"canonical_url":"https://search.dev.ndltd.org/etd/cambridge/oai:www.repository.cam.ac.uk:1810/297741","repository":{"repo_id":"cambridge","name":"Cambridge University","base_url":"https://api.repository.cam.ac.uk/server/oai/request"},"display":{"title":"Doubly charmed B decays with the LHCb experiment","abstract":"$CP$ violation is a necessary ingredient to create a matter-antimatter asymmetry. However, the amount of $CP$ violation incorporated in the Standard Model is orders of magnitude too small to explain the observed asymmetry. This thesis documents two studies of $CP$ violation with doubly charmed $B$ decays. Both were performed using Run I data collected by the LHCb experiment in $pp$ collisions at the LHC. This corresponds to 1.0 fb$^{-1}$ collected at a centre-of-mass energy of 7 TeV and 2.0 fb$^{-1}$ collected at a centre-of-mass energy of 8 TeV. The first analysis is a search for $B_c^+$ decays to two charm mesons, $B_c^+\\to D^{(*)+}_{(s)}D^{(*)}$, where the second charm meson is either $D^0$ or $\\overline{D}{}^0$, which are sensitive to the CKM angle \\gamma. No evidence for signal is found and limits are set on twelve decay modes. The second analysis is the measurement of the $CP$ asymmetry in $B^+\\to D^+_{(s)} \\overline{D}{}^0$ decays. The results are \\begin{align*} \\mathcal{A}^{CP}(B^+\\to D^+_{s} \\overline{D}{}^0) &= (-0.4\\pm 0.5\\pm 0.5)\\%,\\\\ \\mathcal{A}^{CP}(B^+\\to D^+ \\overline{D}{}^0) &= (+2.3\\pm 2.7\\pm 0.4)\\%, \\end{align*} where the first uncertainty is statistical and the second systematic. This is the first measurement of $\\mathcal{A}^{CP}(B^+\\to D^+_{s} \\overline{D}{}^0)$ and the most precise measurement of $\\mathcal{A}^{CP}(B^+\\to D^+\\overline{D}{}^0)$ to date. The results are consistent with $CP$ symmetry.","abstract_html":"$CP$ violation is a necessary ingredient to create a matter-antimatter asymmetry. However, the amount of $CP$ violation incorporated in the Standard Model is orders of magnitude too small to explain the observed asymmetry. This thesis documents two studies of $CP$ violation with doubly charmed $B$ decays. Both were performed using Run I data collected by the LHCb experiment in $pp$ collisions at the LHC. This corresponds to 1.0 fb<span class=\"etd-inline-math\"><sup>-1</sup></span> collected at a centre-of-mass energy of 7 TeV and 2.0 fb<span class=\"etd-inline-math\"><sup>-1</sup></span> collected at a centre-of-mass energy of 8 TeV. The first analysis is a search for <span class=\"etd-inline-math\">B<sub>c</sub><sup>+</sup></span> decays to two charm mesons, <span class=\"etd-inline-math\">B<sub>c</sub><sup>+</sup>\\to D<sup>(*)+</sup><sub>(s)</sub>D<sup>(*)</sup></span>, where the second charm meson is either <span class=\"etd-inline-math\">D<sup>0</sup></span> or <span class=\"etd-inline-math\">\\overline{D}{}<sup>0</sup></span>, which are sensitive to the CKM angle \\gamma. No evidence for signal is found and limits are set on twelve decay modes. The second analysis is the measurement of the $CP$ asymmetry in <span class=\"etd-inline-math\">B<sup>+</sup>\\to D<sup>+</sup><sub>(s)</sub> \\overline{D}{}<sup>0</sup></span> decays. The results are \\begin{align*} \\mathcal{A}^{CP}(B^+\\to D^+_{s} \\overline{D}{}^0) &amp;= (-0.4\\pm 0.5\\pm 0.5)\\%,\\\\ \\mathcal{A}^{CP}(B^+\\to D^+ \\overline{D}{}^0) &amp;= (+2.3\\pm 2.7\\pm 0.4)\\%, \\end{align*} where the first uncertainty is statistical and the second systematic. This is the first measurement of <span class=\"etd-inline-math\">\\mathcal{A}<sup>CP</sup>(B<sup>+</sup>\\to D<sup>+</sup><sub>s</sub> \\overline{D}{}<sup>0</sup>)</span> and the most precise measurement of <span class=\"etd-inline-math\">\\mathcal{A}<sup>CP</sup>(B<sup>+</sup>\\to D<sup>+</sup>\\overline{D}{}<sup>0</sup>)</span> to date. The results are consistent with $CP$ symmetry.","abstract_has_math":true,"creators":["Tully, Alison Maria"],"institution":"University of Cambridge","degree_name":"Doctor of Philosophy (PhD)","degree_level":"Doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Gibson, Valerie"],"committee_chairs":[],"committee_members":[],"year":2019,"date_issued":"2019-10-26","date_published":"2019-10-26","updated_at":"2026-07-22T22:24:06Z","subjects":["LHCb","LHC","CP violation","CKM angle gamma","B physics","CERN","CP asymmetry"],"languages":["en"],"rights":[],"rights_urls":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/3a66fb58-d454-4cd9-a57b-e87bf3d52d86/download","https://creativecommons.org/licenses/by-nc-nd/4.0/"],"identifier_entries":[{"key":"dc:creator.authoridentifier","label":"Author Identifier","values":["0000000287129055"],"render_values":[{"text":"0000-0002-8712-9055","href":"https://orcid.org/0000-0002-8712-9055","code":true}]}]},"links":{"outbound_url":"https://doi.org/10.17863/CAM.44796","outbound_label":"DOI","outbound_source":"dc:identifier.doi"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Gibson, Valerie"]},{"key":"dc:contributor.sponsor","label":"Sponsor","values":["Funded by the Science and Technology Facilities Council (STFC)."]},{"key":"dc:creator","label":"Author","values":["Tully, Alison Maria"]},{"key":"dc:creator.authoridentifier","label":"Author Identifier","values":["0000000287129055"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["2019-10-26"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cambridge"]},{"key":"dc:relation.isreferencedby.uri","label":"Dc Relation Isreferencedby URI","values":["https://www.repository.cam.ac.uk/handle/1810/297741"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["Doctor of Philosophy (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["LHCb","LHC","CP violation","CKM angle gamma","B physics","CERN","CP asymmetry"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/3a66fb58-d454-4cd9-a57b-e87bf3d52d86/download","https://creativecommons.org/licenses/by-nc-nd/4.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.doi","label":"DOI","values":["10.17863/CAM.44796"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/c6a71b2d-1838-4806-80f0-d92b04e61ba2/download"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["$CP$ violation is a necessary ingredient to create a matter-antimatter asymmetry. However, the amount of $CP$ violation incorporated in the Standard Model is orders of magnitude too small to explain the observed asymmetry. This thesis documents two studies of $CP$ violation with doubly charmed $B$ decays. Both were performed using Run I data collected by the LHCb experiment in $pp$ collisions at the LHC. This corresponds to 1.0 fb$^{-1}$ collected at a centre-of-mass energy of 7 TeV and 2.0 fb$^{-1}$ collected at a centre-of-mass energy of 8 TeV. The first analysis is a search for $B_c^+$ decays to two charm mesons, $B_c^+\\to D^{(*)+}_{(s)}D^{(*)}$, where the second charm meson is either $D^0$ or $\\overline{D}{}^0$, which are sensitive to the CKM angle \\gamma. No evidence for signal is found and limits are set on twelve decay modes. The second analysis is the measurement of the $CP$ asymmetry in $B^+\\to D^+_{(s)} \\overline{D}{}^0$ decays. The results are \\begin{align*} \\mathcal{A}^{CP}(B^+\\to D^+_{s} \\overline{D}{}^0) &= (-0.4\\pm 0.5\\pm 0.5)\\%,\\\\ \\mathcal{A}^{CP}(B^+\\to D^+ \\overline{D}{}^0) &= (+2.3\\pm 2.7\\pm 0.4)\\%, \\end{align*} where the first uncertainty is statistical and the second systematic. This is the first measurement of $\\mathcal{A}^{CP}(B^+\\to D^+_{s} \\overline{D}{}^0)$ and the most precise measurement of $\\mathcal{A}^{CP}(B^+\\to D^+\\overline{D}{}^0)$ to date. The results are consistent with $CP$ symmetry."]},{"key":"dc:format.checksum.md5","label":"Dc Format Checksum Md5","values":["e7e3b40a4c903a2d6d67e548edb30a39","87eda9de84448d1f82354d60eee3eb5f"]},{"key":"dc:title","label":"Title","values":["Doubly charmed B decays with the LHCb experiment"]}]}],"canonical_facts":{"dc:contributor.advisor":["Gibson, Valerie"],"dc:contributor.sponsor":["Funded by the Science and Technology Facilities Council (STFC)."],"dc:creator":["Tully, Alison Maria"],"dc:creator.authoridentifier":["0000000287129055"],"dc:date.issued":["2019-10-26"],"dc:description.abstract":["$CP$ violation is a necessary ingredient to create a matter-antimatter asymmetry. However, the amount of $CP$ violation incorporated in the Standard Model is orders of magnitude too small to explain the observed asymmetry. This thesis documents two studies of $CP$ violation with doubly charmed $B$ decays. Both were performed using Run I data collected by the LHCb experiment in $pp$ collisions at the LHC. This corresponds to 1.0 fb$^{-1}$ collected at a centre-of-mass energy of 7 TeV and 2.0 fb$^{-1}$ collected at a centre-of-mass energy of 8 TeV. The first analysis is a search for $B_c^+$ decays to two charm mesons, $B_c^+\\to D^{(*)+}_{(s)}D^{(*)}$, where the second charm meson is either $D^0$ or $\\overline{D}{}^0$, which are sensitive to the CKM angle \\gamma. No evidence for signal is found and limits are set on twelve decay modes. The second analysis is the measurement of the $CP$ asymmetry in $B^+\\to D^+_{(s)} \\overline{D}{}^0$ decays. The results are \\begin{align*} \\mathcal{A}^{CP}(B^+\\to D^+_{s} \\overline{D}{}^0) &= (-0.4\\pm 0.5\\pm 0.5)\\%,\\\\ \\mathcal{A}^{CP}(B^+\\to D^+ \\overline{D}{}^0) &= (+2.3\\pm 2.7\\pm 0.4)\\%, \\end{align*} where the first uncertainty is statistical and the second systematic. This is the first measurement of $\\mathcal{A}^{CP}(B^+\\to D^+_{s} \\overline{D}{}^0)$ and the most precise measurement of $\\mathcal{A}^{CP}(B^+\\to D^+\\overline{D}{}^0)$ to date. The results are consistent with $CP$ symmetry."],"dc:format.checksum.md5":["e7e3b40a4c903a2d6d67e548edb30a39","87eda9de84448d1f82354d60eee3eb5f"],"dc:identifier.doi":["10.17863/CAM.44796"],"dc:identifier.uri":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/c6a71b2d-1838-4806-80f0-d92b04e61ba2/download"],"dc:language":["en"],"dc:publisher.institution":["University of Cambridge"],"dc:relation.isreferencedby.uri":["https://www.repository.cam.ac.uk/handle/1810/297741"],"dc:rights":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/3a66fb58-d454-4cd9-a57b-e87bf3d52d86/download","https://creativecommons.org/licenses/by-nc-nd/4.0/"],"dc:subject":["LHCb","LHC","CP violation","CKM angle gamma","B physics","CERN","CP asymmetry"],"dc:title":["Doubly charmed B decays with the LHCb experiment"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["Doctoral"],"dc:type.qualificationname":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-22T22:24:06Z"}