Search for magnetic monopoles and for nuclearites with the MACRO detector at Gran Sasso

Abstract

We discuss the searches for massive magnetic monopoles (MM) and for nuclearites in the penetrating cosmic radiation performed with the MACRO detector at Gran Sasso. Independent analyses for MM were carried out using the scintillator, streamer tubes and nuclear track subdetectors in different ranges of velocities. No candidates were found in several years of data taking; present flux upper limits for monopoles are well below the Parker bound for monopole velocities ≥ 10 −4c. For nuclearites only the scintillator and nuclear track subdetectors were used; limits are at the level of 10 −15 cm −2s −1sr −1.