Pentaquark Search in Λ⁰_b → Λ⁺_c <span style=

Abstract

This PhD thesis reports results of the physics analysis focused on the search of pentaquarks in Lb->LcDstK decays. Pentaquarks were first reported in 2015 by the LHCb collaboration in jpsi proton system. After collecting more data, further results followed in 2019 and 2022. Observation or non-observation of pc in lcdst system would help to deepen the understanding of these exotic states. The data collected by the LHCb detector at CERN in the years 2015-2018 from proton-proton collisions at center of mass energies of 13 TeV is analyzed. This data amounts to 5.7 fb-1 of integrated luminosity. After reconstructing the missing momentum of the soft pi0 or a gamma from the decay of a Dst meson, the decay dynamics are studied and the search for the pentaquark states in the lcdst system is performed. No signal is observed and the CLs upper limits on the fit fractions for each of the studied pentaquark states are established at 95% confidence level: <br /> f(Pc4312) < 0.52% <br /> f(Pc4440) < 0.65% <br /> f(Pc4457) < 0.54% <br /> The Extended Cone Closure method developed to reconstruct the missing momentum in a 3-body decay could be used for further analyses with missing neutrals. Part of this thesis is dedicated to reporting the work done in preparation for the first LHCb Open Data release. A subset of the LHCb data from the years 2011 - 2012 were made publicly available. The data sets are described with Open Data Records and are available on CERN Open Data Portal. An involved automated workflow was established for data curation and documentation.