Comments on "First Results of the Phase II SIMPLE Dark Matter Search"

TL;DR

This paper critically examines the SIMPLE Collaboration's dark matter search results, questioning the validity of their background event identification and the reliability of their discrimination techniques based on calibration data.

Contribution

It provides a detailed critique of the SIMPLE experiment's data analysis methods and challenges the interpretation of their background discrimination claims.

Findings

Questions the consistency of calibration and physics data distributions.

Raises concerns about background event identification.

Challenges the claimed discrimination between ecays and nuclear recoils.

Abstract

The SIMPLE Collaboration has reported results from their superheated C2ClF5 droplet detectors, including a description of acoustic discrimination between \alpha decays and nuclear recoils. Our concern is that the events in the neutron calibration data and the events identified as neutrons in the physics data are not drawn from the same parent distribution. This fact calls into question the identification of the background events as neutrons, the use of the calibration data to define the acceptance of WIMP-induced nuclear recoils, and the observation of discrimination against \alpha's.