| BaBar creates B and Bbar mesons through the Y(4S) resonance |
 |
The B and Bbar mesons can decay into multiple decay modes. I am interested in studying the mode. This mode can be represented by the following Feynman diagram: |
|
 |
|
|
The negatively charged lepton is detected in the calorimeter of the detector, but the neutrino remains undetected. The D*+ itself decays further in the following process: 
The phasespace available for this decay is minimal (5.5Mev) causing the resulting pion to be of low momentum. Once boosted into the lab frame the charged pion will approximately have the same direction of motion as the D*+ it originated from. Therefore the energy and momentum of the D*+ can be partially reconstructed using the measurements from the pion. In order to detect an event of this kind we must reconstruct the missing mass of the neutrino: 
This will result in a mass peak around 0 MeV 
The tail of energies between -10GeV and -2GeV is the sideband region caused by continuum, peaking and combinatoric background which has to be filtered through data and mote carlo results |
|