A measurement of coherent neutral pion production in neutrino neutral current interactions in the NOMAD experiment (original) (raw)

First Measurement of Neutrino and Antineutrino Coherent Charged Pion Production on Argon

Physical Review Letters, 2014

We report on the first cross section measurements for charged current coherent pion production by neutrinos and antineutrinos on argon. These measurements are performed using the ArgoNeuT detector exposed to the NuMI beam at Fermilab. The cross sections are measured to be 2.7 +1.2 −0.9 (stat) +0.3 −0.4 (syst) × 10 −38 cm 2 /Ar for neutrinos at a mean energy of 9.6 GeV and 6.8 +2.5 −2.0 (stat) +0.8 −0.9 (syst) × 10 −39 cm 2 /Ar for antineutrinos at a mean energy of 3.6 GeV.

First observation of coherent production in neutrino–nucleus interactions with

Physics Letters B, 2008

The MiniBooNE experiment at Fermilab has amassed the largest sample to date of π 0 s produced in neutral current (NC) neutrino-nucleus interactions at low energy. This paper reports a measurement of the momentum distribution of π 0 s produced in mineral oil (CH 2 ) and the first observation of coherent π 0 production below 2 GeV. In the forward direction, the yield of events observed above the expectation for resonant production is attributed primarily to coherent production off carbon, but may also include a small contribution from diffractive production on hydrogen. Integrated over the MiniBooNE neutrino flux, the sum of the NC coherent and diffractive modes is found to be (19.5 ±1.1 (stat) ±2.5 (sys))% of all exclusive NC π 0 production at MiniBooNE. These measurements are of immediate utility because they quantify an important background to MiniBooNE's search for ν µ → ν e oscillations.

Coherent Pion Production by Neutrinos

2009

I concentrate in this article on the reaction coherent pion production by neutrinos incident on nuclei. A special effort is made in order to describe the approximations entering the calculation. I conclude that the reaction is well understood and with appropriate data for hadronic reactions it can be computed for low and high neutrino energies. Because of shortage of space I omitted the resonance analysis, which is described in articles with my collaborators.

Neutrino-induced coherent pion production off nuclei

2009

All available theoretical estimates of neutrino-induced coherent pion production rely on the 'local approximation' for the Delta propagator. The validity of this approximation is scrutinized. It is found that the local approximation overestimates the neutrino-induced coherent pion production on nuclei significantly, by up to 100%.

Coherent pion production by neutrino scattering off nuclei

Physical Review D, 2006

The main part of coherent pion production by neutrinos on nuclei is essentially determined by PCAC, provided that the leptonic momentum transferred square Q 2 remains sufficiently small. We give the formulas for the charged and neutral current cross sections, including also the small non-PCAC transverse current contributions and taking into account the effect of the µ −-mass. Our results are compared with the experimental ones and other theoretical treatments.

Neutrino induced coherent pion production

2010

We discuss different parameterizations of the C A 5 (q 2) N∆ axial form factor, fitted to the old Argonne bubble chamber data for pion production by neutrinos, and we use coherent pion production to test their low q 2 behavior. We find moderate effects that will be difficult to observe with the accuracy of present experiments. We also discuss the use of the Rein-Sehgal model for low energy coherent pion production. By comparison to a microscopic calculation, we show the weaknesses of some of the approximations in that model that lead to very large cross sections as well as to the wrong shapes for differential ones. Finally we show that models based on the partial conservation of the axial current hypothesis are not fully reliable for differential cross sections that depend on the angle formed by the pion and the incident neutrino.

Neutrino-induced coherent pion production off nuclei reexamined

Physical Review C, 2009

It is pointed out that so far all theoretical estimates of coherent pion production off nuclei induced by neutrinos rely on the "local approximation" well known in photonuclear physics. The effects of dropping this approximation are discussed. It is found that in a plane wave approximation for the pion, the local approximation overestimates the coherent neutrino-induced pion production on nuclei.

Coherent pion production in neutrino (anti-neutrino)-nucleus interaction

NPA, 2022

We present a study of coherent pion production in neutrino-nucleus interactions using the formalism based on partially conserved axial current theorem which connects the neutrino-nucleus cross section to the pion-nucleus elastic scattering cross section. Pion-nucleus elastic scattering cross section is calculated using Glauber model which takes three inputs, nuclear densities, pion-nucleon cross section and α πN which is the ratio of real to imaginary part of πN forward scattering amplitude, for which the parametrizations are obtained from measured data. We calculate the differential and integrated cross sections for charge and neutral current coherent pion production in neutrino (anti-neutrino)-nucleus scattering for a range of nuclear targets from light to heavy materials such as lithium, carbon, hydrocarbon, oxygen, silicon, argon, iron and lead. The results of these cross section calculations are compared with the measured data and with the calculations from the Berger-Sehgal model and GENIE package. There is an excellent agreement between the calculated and measured cross sections with Glauber model. While GENIE and Berger-Sehgal model give a good description of the data in the lower energy range the present calculations describe the data in all energy ranges. Predictions are also made for upcoming experiments like INO and DUNE in the coherent region of neutrino cross section.