On the performances of a LaCl3:Ce detector and on some searches for rare processes

2005 - Investigations on the performances of a LaCl3:Ce detector (light response, α/β ratio, pulse shape discrimination capability, radioactive contamination, etc.) and on some possible spontaneous emission of heavy clusters in 138La and 139La nuclides have been carried out. The obtained new limits are reported in the following table:

Although relatively modest, the obtained limits allow to exclude the application of some available empirical formulae for cluster decays in investigated nuclear region.

2006 - The LaCl3:Ce crystal scintillator has been used to search for the first time for the possible CNC decay of 139La into 139Ce.
The cautious obtained limit is:

    τCNC > 1.0 x 1018 yr (90% C.L.)

This limit holds for whatever 139La decay with the emission of massless uncharged particles (γ, Majoron(s), ν, etc., even some other interesting physics which could appear in future).