DAMA/NaI results on a preliminary search for Q-balls

Theories with low-energy supersymmetry predict the existence of stable non-topological solitons, named Q-balls, with mass greater than about 108 GeV, which may be produced in the Early Universe.

2002 - A re-analysis in terms of a preliminary search for Q-balls of the delayed coincidence data with energy above 60 keV collected during 350.05 days by two planes of the ~ 100 kg NaI(Tl) DAMA set-up (previously considered for a SIMPs search) has been performed. No Q-ball candidate has been found and 90% C.L. exclusion plots have been calculated for the model framework given in the related reference. In particular, the obtained 90% C.L. upper limits on Q-balls flux are less stringent than those published e.g. by the lake Baikal underwater Gyrlyanda array, while for charged Q-balls better limits could be reached by analysing the MACRO data. However, the obtained results are the first ones obtained by using crystal scintillators and can be significantly improved in future by exploiting a simpler approach in a larger mass NaI(Tl) set-up.