Search for the 4He-eta bound state in dd->(4He-eta)_{bound}->3He n pi0 and dd->(4He-eta)_{bound}->3He p pi- reactions with the WASA-at-COSY facility

TL;DR

This paper reports on a high-statistics experimental search for the 4He-eta bound state using the WASA-at-COSY facility, analyzing specific nuclear reactions near the eta production threshold.

Contribution

It presents the experimental setup, methodology, and initial data analysis for detecting eta-mesic helium-4 nuclei, a novel search in this nuclear physics domain.

Findings

High-statistics data collected near eta threshold

Analysis of excitation functions for dd reactions

Status update on data analysis process

Abstract

In November 2010, the search for the 4He-{\eta} bound state was per formed with high statistics and high acceptance with the WASA-at-COSY facility using a ramped beam technique. The signature of eta - mesic nuclei is searched for in the measured excitation functions for the two reaction channels: dd ->3He n pi0 and dd ->3He p pi- near the eta production threshold. This report includes the description of the experimental method and the status of the data analysis.