Measurement of muon neutrino and antineutrino induced single neutral pion production cross sections

Abstract

2011Elucidating the nature of neutrino oscillation continues to be a goal in the vanguard of the efforts of physics experiment. As neutrino oscillation searches seek an increasingly elusive signal, a thorough understanding of the possible backgrounds becomes ever more important.Measurements of neutrino-nucleus interaction cross sections are key to this understanding. Searches for ν μ → ν e oscillation-a channel that may yield insight into the vanishingly small mixing parameter θ 13 , CP violation, and the neutrino mass hierarchy-are particularly susceptible to contamination from neutral current single π 0 (NC 1π 0 ) production. Unfortunately, the available data concerning NC 1π 0 production are limited in scope and statistics.Without satisfactory constraints, theoretical models of NC 1π 0 production yield substantially differing predictions in the critical E ν ∼ 1 GeV regime. Additional investigation of this interaction can ameliorate the current de ciencies.e Mini Booster Neutrino Experiment (MiniBooNE) is a short-baseline neutrino oscillation search operating at the Fermi National Accelerator Laboratory (Fermilab). While the oscillation search is the principal charge of the MiniBooNE collaboration, the extensive data (∼ 10 6 neutrino events) offer a rich resource with which to conduct neutrino cross section measurements. is work concerns the measurement of both neutrino and antineutrino NC 1π 0 production cross sections at MiniBooNE. e size of the event samples used in the analysis exceeds that of all other similar experiments combined by an order of magnitude. We present the rst measurements of the absolute NC 1π 0 cross section as well as the rst differential cross sections in both neutrino and antineutrino mode. Speci cally, we measure single differential cross sections with respect to pion momentum and pion angle. We nd the ux-averaged, total cross sections for NC 1π 0 production on CH 2 to be AcknowledgementsImagine my dismay at learning that I did not become the kind of doctor that can order people to take off their pants. Awkward! I must have checked the wrong box on the form.Regardless, it would impolitic of me to fail to acknowledge those I worked (and played) with on my way to becoming a Doctor of Philosophy. e process has been occasionally tedious and quite oen challenging but generally fascinating and always enjoyable. Mathematica, I speak to you as a person because no soware could possibly be so ckle.I liken you to television' s Dr. Gregory House: abrasive and uncooperative to a fault, but always producing beautiful results. I invested countless hours in bending you to my will.Sometimes you would crash in protest and I would lose the day' s work. Well played, Mathematica! Well played, indeed. Aer much struggling, I was able to reliably produce gures in Mathematica, and very oen I would receive compliments for those gures. All told, the ends did justify the means.I am profoundly grateful to the friends in New Haven who provided much needed diversions: Tom, Ethan, Jerry, Kevin, Will, Peter...

U(1) ′ mediated decays of heavy sterile neutrinos in MiniBooNE

“…The decays which do not satisfy our conditions would appear as a diffuse background to two shower events, such as the abundant NC-induced π 0 → γγ events. We have checked that most events outside our selection region have a dilepton invariant mass above 80 MeV, a threshold used to define the MiniBooNE π 0 data sample [36]. We note that MiniBooNE did observe a slight excess in NC π 0 events relative to their Monte Carlo predictions [37], although this was corrected for in the CCQE ν e analysis.…”