Sexaquarks as Dark Matter: predictions and refined constraints

by Glennys Farrar (New York University)

Friday 15 Nov 2019, 14:00 → 16:00 Europe/Rome

Aula Rasetti (Dipartimento di Fisica - Ed. G.Marconi)

The 6-quark dibaryon composed of uuddss is expected to have a mass less than 2 m_Lambda on general “most attractive channel” grounds and coarse Lattice QCD calculations, but has not  been detected in extensive accelerator searches.  In fact, it would have escaped detection in existing searches if the state is stable or very long lived (in which case it is designated S for sexaquark).  Moreover the S appears to be an excellent dark matter candidate.  In this talk, I will review the calculation of the DM relic abundance in this scenario — which is entirely different than in the thermal freezeout scenario — and the reason for expecting the S-BB dissociation vertex gSBB to be < O(10^-6): comfortably compatible with preserving the excellent DM/baryon prediction to low temperatures (contrary to the incorrect claim of Kolb and Turner).  
A hadronic DM candidate, specifically the S, opens fascinating possibilities for DM phenomenology and cosmology which I will discuss.  For a portion of the allowed range of couplings the S can hybridize with nuclei, explaining the observed 10-sigma deficit of 7Li relative to standard BBN  and predicting trace amounts of exotic isotopes which can be searched for.  Strategies for detection in accelerator experiments can also be discussed, depending on audience interests and time permitting.