This project was carried out during REYES 2023 under the guidance of Dr. Sergi Gonzàlez-Solís.
To perform precise measurement of the CKM matrix element |V_ub| using semileptonic B0 -> pi- l+ nu decays.
To run this project locally, ensure you have the following Python libraries installed:
pip install numpy pandas matplotlib scipy The B meson is a bound state consisting of a bottom (b) quark and either an up or down quark. It is an unstable, heavy meson that decays via the weak interaction, making it a valuable probe for studying flavor physics and the elements of the CKM matrix.
Our interest lies in charged current weak interactions, which have their flavor structure encoded in the CKM matrix. The element V_ub connects an up-type quark to a bottom-type quark. However, the Standard Model does not predict specific values for these elements—they must be determined experimentally. Of all the CKM parameters, |V_ub| is one of the least precisely known, and its accurate extraction helps in testing the consistency of the Standard Model.
The full analysis is implemented in the Jupyter notebook vub_determination_reyes.ipynb. The steps followed in the project are:
- Model the hadronic form factor f_+(q^2) using two approaches: a single pole model and a multi-pole model.
- Define the theoretical branching ratio expression as a function of q^2 and |V_ub|.
- Import experimental data of q^2 vs dB/dq^2 for fitting.
- Fit the data using chi-square method to extract the best-fit value of |V_ub|.
- Compare both models and determine which provides the better agreement with the data.
Model 2 (multi-pole) provides a better fit to the experimental data compared to Model 1. The project demonstrates a methodology for extracting flavor physics parameters from decay data using theoretical modeling and numerical optimization.
For queries, feel free to reach out:
Email: khatri.anisha20@gmail.com
LinkedIn: https://linkedin.com/in/AnishaKhatri