The ZEPLIN collaboration has recently published its first result presenting a maximum sensitivity of 1.1×10−6 picobarn for a WIMP mass of ≈ 60 GeV. The analysis is based on a discrimination method using the different time distribution of scintillation light generated in electron recoil and nuclear recoil interactions. We show that the methodology followed both for the calibration of the ZEPLIN-I detector response and for the estimation of the discrimination power is not reliable enough to claim any background discrimination at the present stage. The ZEPLIN-I sensitivity appears then to be in the order of 10−3 picobarn, three orders of magnitude above the claimed 1.1 10−6 picobarn.
@article{arxiv.astro-ph/0512120,
title = {Critical revision of the ZEPLIN-I sensitivity to WIMP interactions},
author = {A. Benoit and M. Chapellier and G. Chardin and L. Dumoulin and K. Eitel and J. Gascon and G. Gerbier and C. Goldbach and J. Jochum and A. de Lesquen and G. Nollez and F. Proebst and W. Seidel},
journal= {arXiv preprint arXiv:astro-ph/0512120},
year = {2008}
}
Comments
8 pages, 4 figures, minor corrections, two references updated, final version accepted in Physics Letters B