Coherent pion production off nuclei at T2K and MiniBooNE energies revisited

Abstract

As a result of a new improved fit to old bubble chamber data of the dominant axial C A 5 nucleonto-Delta form factor, and due to the relevance of this form factor for neutrino induced coherent pion production, we re-evaluate our model predictions in Phys. Rev. D 79, 013002 (2009) for different observables of the latter reaction. Central values for the total cross sections increase by 20%∼30%, while differential cross sections do not change their shape appreciably. Furthermore, we also compute the uncertainties on total, differential and flux averaged cross sections induced by the errors in the determination of C A 5 . Our new results turn out to be compatible within about 1σ with the former ones. Finally, we stress the existing tension between the recent experimental determination of the σ(CCcohπ + ) σ(NCcohπ 0 ) ratio by the SciBooNE Collaboration and the theoretical predictions.

Singleπproduction in neutrino-nucleus scattering

“…[13], using the C A 5 (q 2 ) form factor obtained in Ref [9]. Cross sections for the T2K and MiniBooNE fluxes obtained with this new form factor were given in [41]. The model for coherent pion production is based on the microscopic model for pion production off the nucleon of Ref.…”

“…Given the dominant role played by the ∆P contribution and since ∆ properties are strongly modified in the nuclear medium [13,32,[35][36][37][38][39][40][41] a more proper treatment of the ∆ contribution is needed. Here, we follow Ref.…”

Measurement of Coherent π+ Production in Low Energy Neutrino-Carbon Scattering

“…Different models [2][3][4][5] choose different methods for extension to Q 2 > 0 and implementations of the πA elastic scattering cross section. The validity of these models below neutrino energies of roughly 2 GeV is limited [6][7][8][9]. The second class, known as the microscopic models, was developed specifically for neutrino energies less than 2 GeV [8,[10][11][12][13].…”

Measurement of singleπ0production by coherent neutral-currentνFe interactions in the MINOS Near Detector

“…These interactions can proceed either as neutral-current (NC) or charged-current (CC) processes in which the pion electric charge coincides with that of the Z 0 or W ± vector boson emitted by the leptonic current. Recent investigations, both experimental [2][3][4][5][6] and theoretical [7][8][9][10][11][12][13][14][15][16], have devoted attention to neutrino-induced NC coherent production of single π 0 mesons:…”

“…An alternative class of models, appropriate for subGeV to few-GeV neutrino scattering, has also received considerable attention [11][12][13][14][15][16]. In these "dynamical models" the amplitudes for various neutrino-nucleon reactions yielding the single pion final state are added coherently over the nucleus.…”