Physics

Dr. Nishita Desai
TIFR, Mumbai

<span style="\\&quot;color:" rgb(0,="" 0,="" 0);="" font-family:="" arial,="" helvetica,="" sans-serif;="" font-size:="" 13.3333px;\\"="">Searching for dark matter (DM) has become a priority in beyond standard model searches at the LHC, most of which rely on missing energy signatures.  However, if the DM particle is produced via mediators, the most sensitive searches will be direct searches for the mediators instead.  By constructing a next-to-minimal models of DM (i.e. those that have a mediator charged under Standard Model), we show how such a scenario naturally leads to particles that are long-lived on the scale of the detector and require specialised searches.  We further show that these searches constrain a parameter space that is inaccessible by direct detection, and therefore are crucial to provide full coverage of parameter space. Long-lived particles are a natural feature of models with co-annihilation or in cases where the dark matter density is set by freeze-in.  Consequently, these could be the first collider signal for such models.