Phenomenology of light sneutrino dark matter in cMSSM/mSUGRA with inverse seesaw

Abstract

We study the possibility of a light Dark Matter (DM) within a constrained Minimal Supersymmetric Standard Model (cMSSM) framework augmented by a SM singletpair sector to account for the non-zero neutrino masses by inverse seesaw mechanism. Working within a 'hybrid' scenario with the MSSM sector fixed at high scale and the singlet neutrino sector at low scale, we find that, contrary to the case of the usual cMSSM where the neutralino DM cannot be very light, we can have a light sneutrino DM with mass below 100 GeV satisfying all the current experimental constraints from cosmology, collider as well as low-energy experiments. We also note that the supersymmetric inverse seesaw mechanism with sneutrino as the lightest supersymmetric partner can have enhanced samesign dilepton final states with large E T / coming from the gluino-and squark-pair as well as the squark-gluino associated productions and their cascade decay through charginos. We present a collider study for the same-sign dilepton+jets+E T / signal in this scenario and propose some distinctions with the usual cMSSM. We also comment on the implications of such a light DM scenario on the invisible decay width of an 125 GeV Higgs boson.

A supersymmetric electroweak scale seesaw model

“…Of course, technically speaking we have to expand in I since this is the small parameter while η I is only a bookkeeping parameter equal to one (and not small). After multiplying this equation from left with U −1 PMNS , from right with (U † PMNS ) −1 and inverting the whole equation we find 25) so that the deviation from unitarity is of O( 2 I ) = O(10 −8 ), which is much smaller than current constraints, see, for example, [39], but might be relevant in the future.…”

“…For the sake of brevity we give here a short overview of SUSY ISS models only. To our knowledge these models can be roughly categorized under one of the four categories where each time the additional fields required in the ISS have to be added: (i) MSSM [23][24][25][26], (ii) MSSM/NMSSM with extended gauge symmetry [27][28][29][30][31][32], (iii) NMSSM [17,33], and (iv) supersymmetric Left-Right symmetry model [34,35]. We briefly summarize these models as follows.…”

“…Of course it is also possible and popular to introduce three pairs of the extra gauge singlets with opposite lepton numbers, see, e.g. [23][24][25].…”

Invisible Higgs decay in a supersymmetric inverse seesaw model with light sneutrino dark matter

“…Such a scenario was recently studied in ref. [78] within the framework of cMSSM supplemented by a SM singlet-…”

“…In this paper, we choose to work within the MSSM gauge group and take a hybrid approach for the model parameters similar to that in refs. [78,81] to find suitable benchmark points, i.e. a low energy input for the MSSM singlet fermion sector and for the lepton-number violating soft SUSY-breaking sector while a top-down…”