Search for strange quark matter and Q-balls with the SLIM experiment

TL;DR

This paper reports on a search for exotic particles like strange quark matter and Q-balls using the SLIM nuclear track detector array at high altitude, setting upper limits on their cosmic ray flux.

Contribution

It presents the first experimental search for SQM and Q-balls with the SLIM detector, including flux limits and particle property estimates.

Findings

Flux upper limits of 1.3×10^{-15}/cm^2/s/sr at 90% CL.

No detection of SQM or Q-balls in the data.

Constraints on properties of nuclearites, strangelets, and Q-balls.

Abstract

We report on the search for Strange Quark Matter (SQM) and charged Q-balls with the SLIM experiment at the Chacaltaya High Altitude Laboratory (5230 m a.s.l.) from 2001 to 2005. The SLIM experiment was a 427 m$^{2}$ array of Nuclear Track Detectors (NTDs) arranged in modules of $24 \times 24$ cm$^{2}$ area. SLIM NTDs were exposed to the cosmic radiation for 4.22 years after which they were brought back to the Bologna Laboratory where they were etched and analyzed. We estimate the properties and energy losses in matter of nuclearites (large SQM nuggets), strangelets (small charged SQM nuggets) and Q-balls; and discuss their detection with the SLIM experiment. The flux upper limits in the CR of such downgoing particles are at the level of $1.3 10^{-15}$/cm$^{2}$/s/sr (90% CL).