Effects of final-state interactions in neutrino-nucleus interactions

Final-state interaction (FSI) effects are discussed in the context of Monte Carlo simulations of neutrino-nucleus interactions. A role of formation time is explained and several models describing this effect are compared. Various observables which are sensitive to FSI effects are reviewed including pion-nucleus interaction and hadron yields in backward hemisphere. NuWro Monte Carlo neutrino event generator is described and its ability to understand neutral current ${\pi }^0$ production data in $\sim 1$ GeV neutrino flux experiments is demonstrated.

Figure 1

NuWro predictions for CC scattering cross section (per nucleon) on free isoscalar target in QEL, RES, and DIS channels. The data points are taken from: ANL 12-feet (QEL) [21], ANL 12-feet (RES) [22], BNL 7-feet [23], Nomad [24], SciBooNE [25], MINOS [26].

Figure 2

Double differential cross section in muon scattering angle and kinetic energy for 1 GeV CCQE muon neutrino interaction with carbon as predicted by NuWro FG model implementation. The boxes areas are proportional to the cross section. The maximal cross section is $7.28\times {10}^{-41}{\mathrm{cm}}^2/\mathrm{GeV}$.

Figure 3

Same as Fig. 2, but Fermi gas is replaced by the spectral function The maximal cross section is $5.77\times {10}^{-41}{\mathrm{cm}}^2/\mathrm{GeV}$.

Figure 4

Same as Fig. 2, but for the RES channel. The maximal cross section is $1.40\times {10}^{-41}{\mathrm{cm}}^2/\mathrm{GeV}$.

Figure 5

A block diagram of the NuWro INC algorithm.

Figure 6

Probability (per fermi) of microscopic pion-nucleon interactions in iron as a function of distance from the nucleus center. Pion kinetic energy $T_k=165$ MeV. The Oset model results are taken from [10].

Figure 7

Probability of macroscopic quasielastic or absorption interactions as a function of an impact parameter $b$ for ${\pi }^{+}{}^{40}$Ca scattering with pion kinetic energy $T_k=180$ MeV. The Oset model results are taken from [10].

Figure 8

The ${\pi }^{+}{}^{12}$C absorption cross section. The data points are taken from Ashery [41], Navon [42], Jones [43], and Giannelli [44]. The solid line shows NuWro predictions.

Figure 9

The ${\pi }^{+}{}^{12}$C inelastic cross section. The data points are taken from Ashery [41], Jones [43], and Levenson [45]. The solid line shows NuWro predictions.

Figure 10

The ${\pi }^{+}{}^{12}$C charge exchange cross section. The data points are taken from Ashery [41], Navon [42], and Jones [43]. The solid line shows NuWro predictions.

Figure 11

Average number of backward going pions as a function of $Q^2$ in the NOMAD experiment and in the NuWro simulations.

Figure 12

Laboratory frame nucleon formation zone as a function of nucleon momentum.

Figure 13

Laboratory frame pion formation zone as a function of pion momentum.

Figure 14

K2K: NC $1{\pi }^0$ production as a function of ${\pi }^0$ momentum. NuWro predictions are normalized to the same area as the data.

Figure 15

SciBooNE: NC ${\pi }^0$ production as a function ${\pi }^0$ momentum. NuWro predictions are normalized to the same area as the data.

Figure 16

MiniBooNE (neutrino mode): NC $1{\pi }^0$ production as a function ${\pi }^0$ momentum.

Figure 17

MiniBooNE (antineutrino mode): NC $1{\pi }^0$ production as a function ${\pi }^0$ momentum.

Figure 18

MiniBooNE (neutrino mode): NC $1{\pi }^0$ production as a function $\cos \theta$.

Figure 19

MiniBooNE (antineutrino mode): NC $1{\pi }^0$ production as a function $\cos \theta$.

Figure 20

SciBooNE: NC ${\pi }^0$ production as a function $\cos \theta$.