[Paper Review] Measurements of the reactions C-12 (muon-neutrino, mu-) N-12 (g.s.) and C-12 (muon-neutrino, mu-) X

C. Athanassopoulos, W. Metcalf+35 more|arXiv (Cornell University)|May 23, 1997

Particle physics theoretical and experimental studies35 citations

TL;DR

This study measures charged current neutrino scattering on ¹²C using a muon-neutrino beam at Los Alamos. The exclusive reaction ¹²C(ν_μ, μ⁻)¹²N(g.s.) yields a flux-averaged cross section of (6.6 ± 1.0 ± 1.0) × 10⁻⁴¹ cm², consistent with theory, while the inclusive cross section to all ¹²N states is (11.2 ± 0.3 ± 1.8) × 10⁻⁴⁰ cm², about half the CRPA prediction.

ABSTRACT

Charged current scattering of nu_mu on 12C has been studied using a pi+ decay-in-flight nu_mu beam at the Los Alamos Meson Physics Facility. A sample of 56.8 +- 9.6 events satisfying criteria for the exclusive reaction 12C + nu_mu -> mu- + 12N_g.s. was obtained using the large Liquid Scintillator Neutrino Detector (LSND). The observed flux-averaged cross section, (6.6 +- 1.0 +- 1.0) x 10^-41 cm^2, agrees well with reliable theoretical expectations. A measurement was also obtained for the inclusive cross section to all accessible 12N states, 12C + nu_\mu -> mu- + X. This flux-averaged cross section is (11.2 +- 0.3 +- 1.8)x 10^-40 cm^2, which is approximately half of that given by a recent Continuum Random Phase Approximation (CRPA) calculation.

Motivation & Objective

• To measure the exclusive charged current reaction ¹²C(ν_μ, μ⁻)¹²N(g.s.) using a muon-neutrino beam.
• To determine the inclusive cross section for ¹²C(ν_μ, μ⁻)X to all ¹²N final states.
• To compare measured cross sections with theoretical predictions, particularly the Continuum Random Phase Approximation (CRPA).
• To assess the reliability of theoretical models in describing neutrino-nucleus interactions on carbon.
• To provide precise experimental data for neutrino cross sections relevant to reactor and accelerator neutrino physics.

Proposed method

• Utilized a π⁺ decay-in-flight beam to produce a focused muon-neutrino beam at the Los Alamos Meson Physics Facility.
• Employed the Large Liquid Scintillator Neutrino Detector (LSND) to detect outgoing muons and identify exclusive ¹²N ground state events.
• Applied event selection criteria to isolate the exclusive reaction ¹²C + ν_μ → μ⁻ + ¹²N(g.s.) from background and inelastic processes.
• Measured the inclusive cross section by summing all final states containing a muon and any ¹²N excited state or residual nucleus.
• Calculated flux-averaged cross sections using detector response and beam flux measurements.
• Performed error propagation including statistical and systematic uncertainties to report final cross section values.

Experimental results

Research questions

• RQ1 What is the measured flux-averaged cross section for the exclusive ¹²C(ν_μ, μ⁻)¹²N(g.s.) reaction?
• RQ2 How does the inclusive cross section for ¹²C(ν_μ, μ⁻)X compare to theoretical predictions, particularly the CRPA model?
• RQ3 To what extent does the measured exclusive cross section agree with reliable theoretical expectations?
• RQ4 What is the significance of the discrepancy between the measured inclusive cross section and the CRPA calculation?
• RQ5 How do the LSND detector's capabilities enable precise measurement of neutrino-nucleus scattering on ¹²C?

Key findings

• The flux-averaged cross section for the exclusive reaction ¹²C(ν_μ, μ⁻)¹²N(g.s.) was measured as (6.6 ± 1.0 ± 1.0) × 10⁻⁴¹ cm².
• This exclusive cross section is in good agreement with reliable theoretical expectations.
• The inclusive cross section to all ¹²N final states was measured as (11.2 ± 0.3 ± 1.8) × 10⁻⁴⁰ cm².
• The measured inclusive cross section is approximately half of the value predicted by the Continuum Random Phase Approximation (CRPA) model.
• The results demonstrate the importance of experimental validation for theoretical models in neutrino-nucleus scattering.
• The data provide a benchmark for future studies of neutrino interactions on light nuclei, especially in reactor and accelerator neutrino experiments.