The observation of structures consistent with charmonium-pentaquark states decaying to $J/\\psi p$ in $\\Lambda_b^0 \\rightarrow J/\\psi K^- p$ decays is presented. The data sample analyzed corresponds to an integrated luminosity of 3 $fb^{-1}$ acquired with the LHCb detector from 7 and 8 TeV $pp$ collisions. An amplitude analysis was performed which utilized all six kinematic degrees of freedom in the decay. It was shown that adequate descriptions of the data are unattainable with only $K^- p$ resonances in the amplitude model. For satisfactory fits of the data, it was found to be necessary to include two $J/\\psi p$ resonances, with each having significances of over 9 standard deviations. One has a mass of $4449.8\\pm1.7\\pm2.2$ MeV and a width of $39\\pm5\\pm16$ MeV, while the second is broader, with a mass of $4380\\pm8\\pm29$ MeV and a width of $205\\pm18\\pm87$ MeV. The $J^P$ assignments could not be uniquely determined, though there is a preference for one to have spin $3/2$ and the other spin $5/2$ with an opposite parity to the first. The data sample was also inspected in a model-independent way for the presence of $J/\\psi p$ or $J/\\psi K^-$ contributions. It was demonstrated at more than 9 standard deviations that the data cannot be described with $K^- p$ contributions alone, and that $J/\\psi p$ contributions play a dominant role in this incompatibility. These model-independent results support the model-dependent evidence for $P_c^+\\rightarrow J/\\psi p$ charmonium-pentaquark states provided by the amplitude analysis.
","abstract_html":"<p>The observation of structures consistent with charmonium-pentaquark states decaying to $J/\\psi p$ in \\Lambdab0 \\rightarrow J/\\psi K- p decays is presented. The data sample analyzed corresponds to an integrated luminosity of 3 fb-1 acquired with the LHCb detector from 7 and 8 TeV $pp$ collisions. An amplitude analysis was performed which utilized all six kinematic degrees of freedom in the decay. It was shown that adequate descriptions of the data are unattainable with only K- p resonances in the amplitude model. For satisfactory fits of the data, it was found to be necessary to include two $J/\\psi p$ resonances, with each having significances of over 9 standard deviations. One has a mass of $4449.8\\pm1.7\\pm2.2$ MeV and a width of $39\\pm5\\pm16$ MeV, while the second is broader, with a mass of $4380\\pm8\\pm29$ MeV and a width of $205\\pm18\\pm87$ MeV. The JP assignments could not be uniquely determined, though there is a preference for one to have spin $3/2$ and the other spin $5/2$ with an opposite parity to the first. The data sample was also inspected in a model-independent way for the presence of $J/\\psi p$ or J/\\psi K- contributions. It was demonstrated at more than 9 standard deviations that the data cannot be described with K- p contributions alone, and that $J/\\psi p$ contributions play a dominant role in this incompatibility. These model-independent results support the model-dependent evidence for Pc+\\rightarrow J/\\psi p charmonium-pentaquark states provided by the amplitude analysis.</p>","abstract_has_math":true,"creators":["Jurik, Nathan Philip"],"institution":null,"degree_name":"Doctor of Philosophy (PhD)","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Tomasz Skwarnicki"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-08-01T07:00:00Z","date_published":"2016-08-01T07:00:00Z","updated_at":"2026-07-24T04:55:13Z","subjects":["Hadrons","LHC","LHCb","Pentaquarks","Physical Sciences and Mathematics"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://surface.syr.edu/etd/640","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Tomasz Skwarnicki"]},{"key":"dc:creator","label":"Author","values":["Jurik, Nathan Philip"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_discipline","label":"Discipline","values":["Physics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Hadrons","LHC","LHCb","Pentaquarks","Physical Sciences and Mathematics"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://surface.syr.edu/etd/640"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The observation of structures consistent with charmonium-pentaquark states decaying to $J/\\psi p$ in $\\Lambda_b^0 \\rightarrow J/\\psi K^- p$ decays is presented. The data sample analyzed corresponds to an integrated luminosity of 3 $fb^{-1}$ acquired with the LHCb detector from 7 and 8 TeV $pp$ collisions. An amplitude analysis was performed which utilized all six kinematic degrees of freedom in the decay. It was shown that adequate descriptions of the data are unattainable with only $K^- p$ resonances in the amplitude model. For satisfactory fits of the data, it was found to be necessary to include two $J/\\psi p$ resonances, with each having significances of over 9 standard deviations. One has a mass of $4449.8\\pm1.7\\pm2.2$ MeV and a width of $39\\pm5\\pm16$ MeV, while the second is broader, with a mass of $4380\\pm8\\pm29$ MeV and a width of $205\\pm18\\pm87$ MeV. The $J^P$ assignments could not be uniquely determined, though there is a preference for one to have spin $3/2$ and the other spin $5/2$ with an opposite parity to the first. The data sample was also inspected in a model-independent way for the presence of $J/\\psi p$ or $J/\\psi K^-$ contributions. It was demonstrated at more than 9 standard deviations that the data cannot be described with $K^- p$ contributions alone, and that $J/\\psi p$ contributions play a dominant role in this incompatibility. These model-independent results support the model-dependent evidence for $P_c^+\\rightarrow J/\\psi p$ charmonium-pentaquark states provided by the amplitude analysis.
"]},{"key":"dc:title","label":"Title","values":["Observation of J/psi p resonances consistent with pentaquark states in Lambda_b^0 to J/psi K^- p decays"]}]}],"canonical_facts":{"dc:contributor":["Tomasz Skwarnicki"],"dc:creator":["Jurik, Nathan Philip"],"dc:description.abstract":["The observation of structures consistent with charmonium-pentaquark states decaying to $J/\\psi p$ in $\\Lambda_b^0 \\rightarrow J/\\psi K^- p$ decays is presented. The data sample analyzed corresponds to an integrated luminosity of 3 $fb^{-1}$ acquired with the LHCb detector from 7 and 8 TeV $pp$ collisions. An amplitude analysis was performed which utilized all six kinematic degrees of freedom in the decay. It was shown that adequate descriptions of the data are unattainable with only $K^- p$ resonances in the amplitude model. For satisfactory fits of the data, it was found to be necessary to include two $J/\\psi p$ resonances, with each having significances of over 9 standard deviations. One has a mass of $4449.8\\pm1.7\\pm2.2$ MeV and a width of $39\\pm5\\pm16$ MeV, while the second is broader, with a mass of $4380\\pm8\\pm29$ MeV and a width of $205\\pm18\\pm87$ MeV. The $J^P$ assignments could not be uniquely determined, though there is a preference for one to have spin $3/2$ and the other spin $5/2$ with an opposite parity to the first. The data sample was also inspected in a model-independent way for the presence of $J/\\psi p$ or $J/\\psi K^-$ contributions. It was demonstrated at more than 9 standard deviations that the data cannot be described with $K^- p$ contributions alone, and that $J/\\psi p$ contributions play a dominant role in this incompatibility. These model-independent results support the model-dependent evidence for $P_c^+\\rightarrow J/\\psi p$ charmonium-pentaquark states provided by the amplitude analysis.
"],"dc:identifier":["https://surface.syr.edu/etd/640"],"dc:subject":["Hadrons","LHC","LHCb","Pentaquarks","Physical Sciences and Mathematics"],"dc:title":["Observation of J/psi p resonances consistent with pentaquark states in Lambda_b^0 to J/psi K^- p decays"],"thesis:degree_discipline":["Physics"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-24T04:55:13Z"}