Angular Analysis of $B^{0}\rightarrow K^{*0}e^{+}e^{-}$ Decays at LHCb

The subject of this thesis is the binned angular analysis of $B^{0}\rightarrow K^{*0}e^{+}e^{-}$ decays in the dielectron invariant mass squared ($q^{2}$) regions of $1.1<q^2<6.0\,\mathrm{GeV^{2}/c^{4}}$ and $1.1<q^2<7.0\,\mathrm{GeV^{2}/c^{4}}$ (`central $q^{2}$'), using data collected by the LHCb detector at centre-of-mass energies of 7, 8 and $13\,\mathrm{TeV}$, corresponding to a total of $9\,\mathrm{fb^{-1}}$ of integrated luminosity. The expectation that the Standard Model (SM) is an effective description of nature, and that a more complete model will become necessary at high energies, motivates the search for new particles through direct production, as well as the indirect search for hitherto unknown contributions via precision measurements. Decays featuring the $b\rightarrow s\ell^{+}\ell^{-}$ transition, such as $B^{0}\rightarrow K^{*0}e^{+}e^{-}$, can only occur through higher order processes in the SM to which (virtual) new particles can contribute. They are therefore expected to be particularly sensitive to New Physics (NP) effects. A number of measurements of the angular observables (and differential branching fractions) of $b\rightarrow s\mu^{+}\mu^{-}$ modes in the past decade reported varying levels of tensions with SM predictions. While no single result is robust enough for a claim of discovery, taken together, they seem to hint at common underlying features, which may related to NP contributions or unaccounted for SM effects. The purpose of this analysis is to contribute to the clarification of this picture by providing inputs from the electron mode, which will offer indications on the nature of these tensions. This thesis presents all the major components of the first angular analysis of the $B^{0}\rightarrow K^{*0}e^{+}e^{-}$ mode in the central $q^2$ region at the LHCb, which is expected to be the most precise measurement of its kind to date.