Search for nuclearites using the MACRO detector

Abstract

A negative search using 1/12 of the eventual MACRO detector has yielded nuclearite flux limits of 1.1\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}14}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}2}$ ${\mathrm{sr}}^{\mathrm{\ensuremath{-}}1}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$ for ${10}^{\mathrm{\ensuremath{-}}10}$m0.1 g, and 5.5\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}15}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}2}$ ${\mathrm{sr}}^{\mathrm{\ensuremath{-}}1}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$ for m>0.1 g. We have modified the formula of De R\'ujula and Glashow for the light yield of nuclearites to include the uv light absorbed and reemitted in the visible region, and proved that the MACRO sensitivity extends almost to the escape velocity of the Earth. Our flux limit, therefore, can be used to address nuclearites that are possibly trapped in the solar system.