Alice Biolchini, promovenda aan het Nikhef, verdedigt haar proefschrift donderdag 18 september 2025 om 11.45 aan de Vrije Universiteit Amsterdam.
“Beauty from every angle”
The universe is fundamentally dark: stars do not shine, the Sun is not luminous, and the Moon does not reflect light. Light exists only when there are eyes and a brain to transform it into perception, making the cosmos visible to us. Similarly, human knowledge remains in darkness: without eyes and a brain to transform information into understanding, what exists remains unseen. Particle detectors such as LHCb act as new “eyes,” allowing us to glimpse otherwise hidden structures of matter and forces.
In particular, this thesis focuses on the study of a decays of beauty mesons, specifically the decay B0->K*0e^+e^-, using data collected during LHC Run1 and Run2 with the LHCb experiment at CERN. These processes, in which a bottom quark changes flavour via a loop-mediated neutral current (the so-called “penguin” diagram), are highly suppressed in the Standard Model and thus particularly sensitive to potential contributions from physics beyond the Standard Model.
The core objective of this project is to investigate this decay channel by measuring angular observables in three regions of the di-electron invariant mass squared (q^2): [1.1−6.0] GeV^2/c^4 and the two sub-regions [1.10−3.65] and [3.65−6.00] GeV^2/c^4. This is achieved through a comprehensive analysis pipeline which includes data selection, background suppression, and the construction of an angular fit model that incorporates detector effects through an acceptance function.
To ensure robustness, the impact of assumptions – such as neglected backgrounds or chosen functional forms – is systematically evaluated. While the final angular distributions in data remain blinded to avoid human biases, the aim of my thesis is to evaluate the expected sensitivity – both in terms of statistical and systematic uncertainties – to the angular coefficients in each q^2 region.
These measurements contribute to ongoing efforts in experimental particle physics to test the limits of the Standard Model and search for potential indirect signatures of physics beyond the Standard Model through precision measurements.
De promotie vindt plaats in het hoofdgebouw van de Vrije Universiteit Amsterdam, De Boelelaan 1105, 1081 HV, Amsterdam
Meer informatie en een link naar de online livestream op de website van de VU.
Promotor: prof. dr. H.G. Raven
Co-promotor: dr. M. Senghi Soares
Contact: Alice Biolchini
