Measurement of Coherent Production ofπ±in Neutrino and Antineutrino Beams on Carbon fromEνof 1.5 to 20 Ge

Abstract

Neutrino-induced coherent charged pion production on nuclei νμA→μ(±)π(∓)A is a rare, inelastic interaction in which a small squared four-momentum |t| is transferred to the recoil nucleus, leaving it intact in the reaction. In the scintillator tracker of MINERvA, we remove events with evidence of particles from nuclear breakup and reconstruct |t| from the final-state pion and muon. We select low |t| events to isolate a sample rich in coherent candidates. By selecting low |t| events, we produce a model-independent measurement of the differential cross section for coherent scattering of neutrinos and antineutrinos on carbon. We find poor agreement with the predicted kinematics in neutrino generators used by current oscillation experiments.

Measurement of total and differential cross sections of neutrino and antineutrino coherent π± production on carbon

“…The cross sections are measured as a function of the pion energy, pion angle, and Q 2 , which characterize the coherent pion production kinematics. A subset of these results based on these same data was published earlier [1]. The results presented in this paper have a revised treatment of backgrounds, additional differential distributions, a new prediction of the neutrino and antineutrino fluxes in the beam and the correlations between the neutrino and antineutrino measurements.…”

“…Rates for interactions where there are no applicable measurements were taken from the hadron interaction model used in the simulation (FTFP-BERT). 1 Predictions from the weighted model were compared against in situ measurements of neutrino scattering events with low hadronic recoil to validate the model. An in situ measurement [41] of ν þ e − → e − þ ν provided an additional constraint on the flux, giving a roughly 2%-4% reduction in the flux prediction and an ∼1% reduction in the flux uncertainty.…”

“…Diffractive pion production on a free proton. 1 FTFP shower model in GEANT4 version 9.2 patch 03. 2 The y axis points along the zenith and the beam is directed downward by 58 mrad in the y-z plane.…”

Pion Production at MINERvA

“…The calculation of |t|, from directly measured kinematic variables of the muon and pion, allowed a model-independent measurement of the coherent differential cross section [8]. The model to which the data were compared to (Rein-Sehgal [8]), poorly reproduced the measured kinematics ( fig.…”

Recent results from ArgoNeuT and status of MicroBooNE

“…Thanks to its fine grained resolution ArgoNeuT is able to perform measurements of exclusive cross-section topologies as well as observe clear indications of nuclear interactions in the argon nucleus affecting the topologies and parti- The measurement of the coherent pion production recently performed by ArgoNeuT [17] has shown that even a prototype LArTPC can compete with other detector technologies that have recently looked at this channel [18,19]. ArgoNeuT, due to its small size which prevented the containment of pions and therefore the efficient use of variables such as Q 2 and |t|, used a boosted decision tree to select candidate events based on the combined values of several kinematic variables, including the opening angle and presence of additional activity near the vertex.…”