# $\Lambda p$ Elastic Scattering in the CLAS Detector

## TL;DR

This paper reports on a novel analysis of $ ext{Lambda} p$ elastic scattering using CLAS detector data, revealing a significant number of events and opening new avenues for studying short-lived particle interactions.

## Contribution

It introduces a new method of analyzing $ ext{Lambda} p$ scattering using existing CLAS data, achieving higher event counts than previous measurements.

## Key findings

- Detected a strong $ ext{Lambda}$ peak with twice the world data sample
- Demonstrated CLAS's suitability for secondary beam measurements
- Established a foundation for future short-lived particle studies

## Abstract

The elastic scattering process $\Lambda p\to\Lambda p$ offers insights on multiple problems in nuclear physics. $\mathrm{SU}(3)_F$ symmetry implies a close agreement between the $\Lambda p$ and $pp$ scattering cross sections. The $\Lambda p$ elastic scattering cross section can also illuminate the structure of neutron stars. A data-mining project was started using multiple CLAS data sets taken for other purposes with photon beams on a long liquid hydrogen target. A $\Lambda$ produced in a process such as $\gamma p\to K^+\Lambda$ can interact with a second proton inside the target before either decaying or leaving the target. The good angular acceptance and momentum resolution of CLAS make it well-suited for this type of analysis, even though it was not designed for such a measurement. The scattered $\Lambda$ can be identified from the $\pi^-p$ invariant mass. The four-vector of the initial $\Lambda$ is then reconstructed in the process $Xp\to\Lambda p$, which shows a strong peak at the $\Lambda$ mass with roughly twice the number of events as the existing world data sample. This observation opens up the possibility of other measurements using secondary beams of short-lived particles. This paper will discuss the current status of the analysis, and our plans for future work on this project.