Speaker
Description
Single kaon production in neutrino interactions is a rare process with relevance for both neutrino–nucleus studies and searches for physics beyond the Standard Model. In particular, neutral-current flavor transitions such as $\bar{d} \rightarrow \bar{s}$ are strongly suppressed in the Standard Model, making the reaction $\nu p \rightarrow \nu K^+ n$ a possible probe of non-standard interactions.
Motivated by the recent MicroBooNE measurement of $K^+$ production in charged-current interactions, we have studied Cabbibo-suppressed single-kaon production including so far unaccounted nuclear effects. We analyze the role of this reaction mechanism in the measured signal and compare our results to the GiBUU and GENIE predictions, aiming to understand how strangeness production is implemented in these generators and which channels contribute to the observed $K^+$ events.
We have also extended the model to the neutral-current case, relating the corresponding hadronic matrix elements to the charged-current ones through isospin rotations, and expressing the cross section in terms of an unknown Wilson coefficient for the still poorly constrained axial flavor-changing transition. We investigate if, with the current bounds, neutral current $K^+$ induced by atmospheric neutrinos could coexist with potential signatures of proton decay in the channel $p \rightarrow \bar{\nu} K^+$, searched for at Super-Kamiokande and expected to be further explored at DUNE and Hyper-Kamiokande.