# Energy and Flavor Discrimination Using Precision Time Structure in On-Axis Neutrino Beams

## TL;DR

This paper introduces a timing-based method using high-frequency RF bunch structures and precision timing to discriminate neutrino energy and flavor spectra in on-axis beams, enhancing neutrino experiments.

## Contribution

It proposes a novel stroboscopic approach leveraging RF bunch structure and superconducting RF cavities to improve neutrino energy and flavor discrimination.

## Key findings

- High-frequency RF bunching reduces proton bunch length to ~100 ps.
- Timing-based discrimination complements angular methods.
- Method applicable to both near and far detectors.

## Abstract

We propose to use a higher-frequency RF bunch structure for the primary proton beam on target and precision timing to select different energy and flavor spectra from a wide-band neutrino beam, based on the relative arrival times of the neutrinos with respect to the RF bunch structure. This `stroboscopic' approach is complementary to techniques that select different neutrino energy spectra based on the angle with respect to the beam axis. A timing-based approach allows for the selection of varying energy spectra from the same on-axis detector, and applies equally to both the near and far detectors in an oscillation experiment. Energy and flavor discrimination of neutrinos produced by hadrons in-flight will require proton bunch lengths on the order of 100 ps and commensurate time resolution in the detector. Correlating neutrino events with the parent proton interaction is currently limited by the nanosecond-scale width of the proton bunches impinging on the target. We show that these limitations can be addressed by using a superconducting RF cavity to rebunch the present 53.1 MHz RF bunch structure with a factor of 10 higher RF frequency, thus attaining the required shorter bunch length.