Search of strange quark matter using MACRO detector

Abstract

The MACRO detector is sensitive to wide range of ionizing massive particles in cosmic rays. These include “nuclearites” or strange quark matter. The negative result of a search lasting about 20 months using $\text{1}\text{12}$ of the detector has yielded a flux limit of 1.1 × 10⁻¹⁴ cm⁻²sr⁻¹s⁻¹ for strange matter with mass 10⁻¹⁰ g < m < 0.1 g. For m > 0.1g, the limit is 5.5 × 10⁻¹⁵cm⁻²sr⁻¹s⁻¹. Since the velocity range of nuclearites to which MACRO is sensitive extends down to near the escape velocity of the earth, the flux limit not only applies to nuclearites of galactic or extra-galactic origin but also applies to nuclearites that are trapped in the solar system.