Proposal for a Hadron Blind Detector for PHENIX

TL;DR

The paper proposes a Hadron Blind Detector upgrade for PHENIX at RHIC, designed to measure low-mass electron pairs with high efficiency and pion rejection, using a novel Cherenkov detector with GEM technology.

Contribution

It introduces a new detector design for PHENIX that enhances low-mass e+e- pair measurement capabilities in heavy-ion collisions.

Findings

Simulations show >90% electron identification efficiency

Double hit recognition exceeds 90%

Pion rejection factor around 200

Abstract

A Hadron Blind Detector (HBD) is proposed as upgrade of the PHENIX detector at RHIC, BNL. The HBD will allow the measurement of low-mass e+e- pairs from the decay of the light vector mesons rho, omega, phi and the low-mass continuum in Au-Au collisions at energies up to sqrt{s_{NN}}= 200 GeV. From MC simulations and general considerations, the HBD has to identify electrons with very high efficiency (> 90%), double hit recognition better than 90%, moderate pion rejection factor of ~200 and radiation budget of the order of 1% of a radiation length. The first choice under study is a windowless Cherenkov detector, operated with pure CF4, in a special proximity focus configuration with a CsI photocathode and a multistage GEM amplification element.