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Analysis using collision data to select candidates based on invariant mass criteria, fitting mass distribution with Gaussian models, and evaluating reconstruction efficiencies without Monte Carlo input. Challenges and prospects for measuring efficiencies from data.
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in 900 GeV collision data Ehud Duchovni Ofir Gabizon
Selection of candidates Each candidate is required to satisfy: The invariant mass of the two tracks, treated as massless is required to satisfy: (to remove conversions) For all plots except mass reconstruction, The invariant mass of the two tracks, treated as pions is required to satisfy
Reconstruction of mass • The mass distribution of candidates fitted to a single Gaussian:
The mass distribution of candidates fitted to a double Gaussian:
Attempt to measure efficiencies from data • It was thought that the reconstruction efficiency might be obtainable from the measured decay distance and distributions without MC input by using the known lifetime distribution. • This set of equations describes the relationship between the distributions after binning: • Without further assumptions there is variables and equations. One must make further assumptions to be able to solve these equations • However, since the reconstruction efficiency is a strong function of the parameters this is problematic
Prospects • Seeking new approaches for measuring the reconstruction efficiency from data