MicroBooNE is an attempt to measure neutrino mixing angles. To achieve this, electron-neutrino events arising from a beam of muon-neutrinos need to be differentiated to detect flavor changes. Our goal was to create a procedure to reliably identify these electron-neutrino events and reject all of the other background events. This was accomplished by examining simulations of MicroBooNE events generated by Monte Carlo methods using LArSoft (Liquid Argon Software) and determining specific characteristics inherent to different interactions.†
To see what some of these events or the LArSoft EventDisplay look like, please check out the poster or presentation.
Week 1: Learning about the MicroBooNE experiment, the theory behind neutrino oscillations, and how to run and operate LArSoft.
Weeks 2 and 3: Learned about different scattering modes (quasi-eleactic, resonant, deep-inelastic) and modes of interaction (charged-current or neutral-current.) Began generating and examining single particle simulations with the TruthView function of LArSoft.
Week 4 and 5: Examining simulated neutrino events. Began using the EventDisplay function of LArSoft.†
Week 6: Started looking at simulations for specific interactions, both CC and NC for QE, RES, and† DIS. Began hand-scanning.
Week 7: First steps in formulating an algorithmic procedure to differentiate CC e events.
Week 8: Finished creating procedure. Conducted an efficiency test to analyze procedure.
Week 9: Attended a MicroBooNE collaboration meeting at Fermilab and presented findings.
Week 10: Created final reports and presentation.
- Discard all events not containing a primary interaction vertex.
- These are intractable and can not be used.
- Discard all events not containing an electromagnetic shower.
- Charged-current νe events will always produce an electron, which creates a tell-tale shower.
- Discard all events containing distinctive μ tracks.
- μís have characteristically long, straight, minimum ionizing tracks.
- μís are produced in charged-current νμ events and as such can be ruled out.
Step 4:-Determine the shower origin and discard non-electron induced events.
- The candidates are: π0, π+, γ, and electrons.
†- γís leave gaps between the shower and the vertex and can be identified by this.
- π+ís go through a decay before showering and can be found through bends in their tracks.
Results and Conclusions
An efficiency trial was conducted with 100 random events of all types. Our algorithmic procedure was able to reject 98% of the background noise and keep all of the νe signal. However, several π0 ís were misidentified as electrons. Further studies still need to be conducted on π0 identification as well as on heavier particles, such as K+, Σ+, Λ0.