Observation of new Ξ꜀⁰ states decaying to Λ꜀⁺K⁻, and development of the TORCH time-of-flight detector
dc.contributor.advisor
Muheim, Franz
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dc.contributor.advisor
Needham, Matthew
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dc.contributor.author
Gabriel, Emmy Pauline Maria
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dc.date.accessioned
2020-06-15T16:13:45Z
dc.date.available
2020-06-15T16:13:45Z
dc.date.issued
2020-06-25
dc.description.abstract
Using a data sample of proton-proton collisions at center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 5.6 fb-1 collected by the LHCb experiment, the Λc+K- mass spectrum is studied.
Three new, excited Ξc0 states are observed and their masses and natural widths are measured to be
m(Ξc(2923)0) = 2923.04 ± 0.25 ± 0.18 ± 0.14 MeV,
Γ(Ξc(2923)0) = 7.09 ± 0.79 ± 1.39 MeV,
m(Ξc(2939)0) = 2938.55 ± 0.21 ± 0.17 ± 0.14 MeV,
Γ(Ξc(2939)0) = 10.22 ± 0.77 ± 1.04 MeV,
m(Ξc(2965)0) = 2964.88 ± 0.26 ± 0.14 ± 0.14 MeV,
Γ(Ξc(2965)0) = 14.07 ± 0.91 ± 1.34 MeV,
where the uncertainties are statistical, systematic and the third one is due to the knowledge of the Λc+ mass. All peaks have significances greatly exceeding 5σ. Though the mass of Ξc(2965)0 is close to the known Ξc(2970)0 its natural width differs significantly and therefore it is interpreted as a different baryon.
Furthermore, this thesis summarises the status of the TORCH time-of-flight detector by describing the characterisation of Micro-Channel Plate Photomultiplier tubes (MCP-PMTs), outlining the recent beam test campaigns as well as an analysis comparing the photon yield in simulation and data.
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dc.identifier.uri
https://hdl.handle.net/1842/37129
dc.identifier.uri
http://dx.doi.org/10.7488/era/430
dc.language.iso
en
dc.publisher
The University of Edinburgh
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dc.subject
LHCb
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dc.subject
Large Hadron Collider
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dc.subject
TORCH time-of-flight detector
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dc.title
Observation of new Ξ꜀⁰ states decaying to Λ꜀⁺K⁻, and development of the TORCH time-of-flight detector
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dc.type
Thesis or Dissertation
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dc.type.qualificationlevel
Doctoral
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dc.type.qualificationname
PhD Doctor of Philosophy
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