This is a repo which will store code I have done/am doing for my final-year project. The aim of the project as a whole is to investigate B --> X mu+mu- decays at the LHCb, which seem to be (from previous searches) a potential avenue towards new physics. So the idea is to conduct an inclusive search (previous forays have primarily been exclusive), which provides a better environment for the theorists to make predictions. However, on the experimental/data-analysis side, inclusive searches are a lot more difficult than exclusive ones. The main issue is the background, which mostly stems from cascade decays e.g. B0 --> D (K mu nu) mu, which can masquerade as a signal, because in the inclusive search all we look for are the two muons.
Currently we have identified that there are two distinct regions:
- High Q2, in which backgrounds are small and stem from combinatorial sources, and we can apply control data sets and extrapolation to estimate the backgrounds (we hope)
- Low Q2, in which background comes from the more-thorny cascade decays.
- Comparison of high- and low-Q2 regions.
- Generation of plots overlaying simulated signal and background in both regions for analysis and comparison.
- Creation of a Boosted Decision Tree or Neural Network to conduct a Multivariate Analysis to separate the signal from background.
- Train MVA on Monte Carlo-simulated signal and background
- Apply MVA to real data.
- In ROOT:
- To Open TMVAGui:
.x /cvmfs/lhcb.cern.ch/lib/lcg/releases/LCG_69/ROOT/5.34.21/x86_64.../tmva/test/TMVAGui.C(<MVA output file name>)
- To Open TMVAGui: