Abstract
We report on an updated sensitivity for proton decay via p → overline{nu} K+ at large, dual phase liquid argon time projection chambers (LAr TPCs). Our work builds on a previous study in which several nucleon decay modes have been simulated and analyzed [1]. At the time several assumptions were needed to be made on the detector and the backgrounds. Since then, the community has made progress in defining these, and the computing power available enables us to fully simulate and reconstruct large samples in order to perform a better estimate of the sensitivity to proton decay. In this work, we examine the benchmark channel p → overline{nu} K+, which was previously found to be one of the cleanest channels. Using an improved neutrino event generator and a fully simulated LAr TPC detector response combined with a dedicated neural network for kaon identification, we demonstrate that a lifetime sensitivity of τ /Br (p → overline{nu} K+) > 7 × 1034 years at 90% confidence level can be reached at an exposure of 1 megaton · year in quasi-background-free conditions, confirming the superiority of the LAr TPC over other technologies to address the challenging proton decay modes.
Highlights
Event generator, a well-defined design for a ∼10 kiloton DP LAr TPC, a validated detector simulation based on data of the 3 × 1 × 1 m3 DP LAr TPC prototype [17, 18], a full reconstruction with aided pattern recognition and a neural-network-driven kaon identification
Using an improved neutrino event generator and a fully simulated LAr TPC detector response combined with a dedicated neural network for kaon identification, we demonstrate that a lifetime sensitivity of τ /Br p → νK+ > 7 × 1034 years at 90% confidence level can be reached at an exposure of 1 megaton · year in quasi-background-free conditions, confirming the superiority of the LAr TPC over other technologies to address the challenging proton decay modes
The DP LAr TPC detector design used in this study is considered as option for the Deep Underground Neutrino Experiment (DUNE) far detector complex, which will deploy a total of four ∼10 kiloton single and dual phase LAr TPCs [19]
Summary
2.1 Signal and backgrounds Proton decay via p → νK+ in argon constitutes the signal and atmospheric neutrino interactions with argon are considered as background. Resonant single kaon production without accompanying hyperons is possible in CC interactions if the exchanged W − boson turns an up quark into a strange quark to produce a strange baryon resonance that can decay into a neutral or negatively charged kaon and a nucleon. This process is not implemented in GENIE, but since it’s Cabibbo suppressed and the charged lepton from the CC interaction makes it distinguishable from the signal, it is not expected to have a big impact on the presented results. Single kaons from DIS typically have higher energies than the K+ from proton decay via p → νK+ and the charged lepton produced in these interactions is another handle to distinguish them from proton decay
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
