A Disoriented Chiral Condensate Search at the Fermilab Tevatron

TL;DR

This study used the MiniMax detector at Fermilab to search for disoriented chiral condensates in proton-antiproton collisions, employing robust observables that are insensitive to many systematic uncertainties, but found no evidence of DCC production.

Contribution

The paper introduces a novel set of robust observables for DCC detection that are insensitive to detector efficiencies and modeling uncertainties, and applies them to a large dataset at Fermilab.

Findings

No evidence of DCC observed in the data

Robust observables are effective in discriminating DCC from generic events

Simulations confirm insensitivity of observables to systematic errors

Abstract

MiniMax (Fermilab T-864) was a small test/experiment at the Tevatron designed to search for disoriented chiral condensates (DCC) in the forward direction. The MiniMax detector at the C0 collision region of the Tevatron was a telescope of 24 multi-wire proportional chambers (MWPC's) with a lead converter behind the eighth MWPC, allowing the detection of charged particles and photon conversions in an acceptance approximately a circle of radius 0.6 in pseudorapidity-azimuthal-angle space, centered on a pseudorapidity of about 4. The use of standard Monte Carlo simulations (PYTHIA, GEANT) is described, along with the simulation created by the MiniMax Collaboration to generate DCC domains. A description of the data analysis software is given, including detailed studies of its performance on data from the simulations. A set of robust observables is derived. These are insensitive to many efficiencies and to the details of the modeling of the parent pion production mechanisms, yet have distinguishable values for DCC and generic charged-neutral distributions. Simulations show that the robust observables are insensitive to detector efficiencies and to systematic errors in the data analysis software. The resulting values for robust observables for approximately 1.5 million events are shown to be consistent with production by only generic mechanisms. Results from samples of diffractive-tagged events and of high-multiplicity events also show no evidence for DCC.