TY  - GEN
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/29883/
KW  - Physik
KW  -  Elementarteilchenphysik
KW  -  LHC
KW  -  LHCb
KW  -  Standardmodell
KW  -  Datenanalyse
KW  -  Flavor Anomalien
Y1  - 2021///
CY  - Heidelberg
A1  - Gerick, David
ID  - heidok29883
AV  - public
TI  - Search for physics beyond the standard model in an angular analysis of the B??K*????? decay at LHCb
N2  - In this thesis an angular analysis of the B??K*????? decay with the subsequent decays K*??K?S?? and K?S????? is presented. The full data set collected by the LHCb experiment during the first two periods of pp collisions at the Large Hadron Collider in the years 2011-2018 is used. In total, 737±34 signal candidates are selected, which allows to determine all angular observables and their correlations in the B??K*????? decay for the first time. Furthermore, it is the first time that all angular observables are measured in a b?sl?l? transition other than that included in the decay of the neutral B? meson. A four-dimensional maximum-likelihood fit is used to extract two sets of angular observables in ten intervals of the invariant dimuon mass squared, q². For most observables and in most q² intervals the resulting values are compatible with Standard Model predictions. However, most prominently the CP-averaged (and optimised) angular observables Afb (P2) and S5 (P5') show significant discrepancies from Standard Model predictions in the q² region below the J/? resonance. A global evaluation of the result in terms of the real part of the underlying vector coupling strength in the model-independent effective field theory description prefers a shift of ?Re(C9)=?1.9 from the Standard Model value with a significance of 3.1?.
The pattern of deviation is coherent with previous measurements in the isospin-partner decay of the B? meson. The size of the deviation largely depends on the considered q² regions and choice of theory nuisance parameters for the global fit.
ER  -