Pion-proton correlation in neutrino interactions on nuclei

Abstract

In neutrino-nucleus interactions, a proton produced with a correlated pion might exhibit a leftright asymmetry relative to the lepton scattering plane even when the pion is absorbed. Absent in other proton production mechanisms, such an asymmetry measured in charged-current pionless production could reveal the details of the absorbed-pion events that are otherwise inaccessible. In this study, we demonstrate the idea of using final-state proton left-right asymmetries to quantify the absorbed-pion event fraction and underlying kinematics. This technique might provide critical information that helps constrain all underlying channels in neutrino-nucleus interactions in the GeV regime.

Probing nuclear effects with neutrino-induced charged-current neutral pion production

“…[44] indicate that the final-state π 0 could prefer one side of the scattering plane due to the interference between delta and nonresonant amplitudes (see Ref. [15] for discussions). Without loss of generality, suppose the proton in Eq.…”

“…In previous studies, MINERνA measured the final-state correlations in neutrino charged-current (CC) quasielastic (QE)-like interactions on carbon [6,7]. These correlations are based on transverse kinematic imbalance (TKI) that helps precisely identify intranuclear dynamics [6][7][8][9][10][11][12][13][14][15] or the absence thereof [16][17][18][19][20]. The previously measured imbalance is between the CC muon and the final-state proton; the present work studies the following reaction including additional neutral pions in the final state:…”

“…Ref. [15] and references therein), any particle-typedependent nuclear effects could cause an asymmetric distribution of δp TT . This paper presents the first measurement of this new TKI.…”

Measurement of the muon neutrino charged-current single π+ production on hydrocarbon using the T2K off-axis near detector ND280

“…In particular pion production, absorption and charge exchange processes, shift the event classification between CC1π þ and other final states and in experimental measurements these effects cannot be unfolded from the fundamental single nucleon cross section without relying on a specific model. A detailed understanding of the CC1π þ interaction, such as the left-right asymmetry of the final-state hadron with respect to the lepton scattering plane, may help to constrain the absorbed pion background contribution to the CCQE-like neutrino interactions [16].…”

Neutrino interaction physics and the DUNE near detector

“…Transverse Kinematic Imbalance (TKI) is a technique that helps precisely identify intranuclear dynamics [8][9][10][11][12][13][14][15][16][17][18] or the absence thereof [19][20][21][22][23] in neutrino-nucleus interactions. Applications of this technique in MINERvA's carbon hydrocarbon target [8][9][10] and T2K [16] show good agreement…”