- March 17, 2022, 2:30 pm US/Central
- Alexis Nikolakopolous, FNAL
- Noemi Rocco
The model for neutrino-induced pion production of [R. Gonzalez-Jimenez et al. Phys. Rev. D 95, 113007 (2017)] is used to describe data for charged-current interactions off carbon in the T2K and MINERvA experiments.
This work extends the approach of [Hernandez Nieves and Valverde, Phys. Rev. D 76, 033005 (2007)] to higher hadronic invariant mass by making use of Regge phenomenology to construct the background amplitude at high energies.
Results are compared to the MAID07 [Drechsel, Kamalov and Tiator, Eur. Phys. J. A34, 69-97 (2007) ] and ANL-Osaka DCC [S.X. Nakamura, H. Kamano and T. Sato, Phys. Rev. D92, 074024 (2015)] analyses of electroproduction data, in particular the isovector contribution relevant to CC interactions is isolated.
The model is implemented in the nucleus in the Relativistic Distorted Wave Impulse Approximation (RDWIA), making use of the real energy-dependent potential of [R. Gonzalez-Jimenez et al., Phys. Rev. C100 045501 (2019)].
This potential is identical to the relativistic mean field potential used for the bound states at low nucleon energies, such that initial and final-state wavefunctions are treated consistently and spurious non-orthogonal contributions to the matrix element are avoided.
For flux-averaged angle-integrated cross sections, the RDWIA approach leads to only a mild reduction compared to results obtained in the relativistic plane wave impulse approximation.
The results for positive pion production data in both T2K and MINERvA are satisfactory, but the low-Q^2 region is overpredicted.
Although the situation remains unclear, we point to the poorly constrained axial coupling as a possible source of this discrepancy, rather than a nuclear effect as is often advocated.