Z_{B}^{L '} portal dark matter and LHC Run2 results
Abstract
We consider a concise dark matter scenario in the minimal gauged B L extension of the standard model (SM), where the global B L (baryon number minus lepton number) symmetry in the SM is gauged, and three generations of righthanded neutrinos and a B L Higgs field are introduced. Associated with the B L gauge symmetry breaking by a VEV of the B L Higgs field, the seesaw mechanism for generating the neutrino mass is automatically implemented after the electroweak symmetry breaking in the SM. In this model context, we introduce a Z_{2}parity and assign an odd parity for one righthanded neutrino while even parities for the other fields. Therefore, the dark matter candidate is identified as the righthanded Majorana neutrino with odd Z_{2} parity, keeping the minimality of the particle content intact. When the dark matter particle communicates with the SM particles mainly through the B L gauge boson (Z_{B}^{L '} boson), its relic abundance is determined by only three free parameters, the B L gauge coupling (α_{B L}), the Z_{B}^{L '} boson mass (m_{Z'}) and the dark matter mass (m_{DM}). With the cosmological upper bound on the dark matter relic abundance we find a lower bound on α_{B L} as a function of m_{Z'}. On the other hand, we interpret the recent LHC Run2 results on search for Z^{'} boson resonance to an upper bound on α_{B L} as a function of m_{Z'}. Combining the two results we identify an allowed parameter region for this "Z_{B}^{L '} portal" dark matter scenario, which turns out to be a narrow window with the lower mass bound of m_{Z'}>2.5 TeV .
 Publication:

Physical Review D
 Pub Date:
 April 2016
 DOI:
 10.1103/PhysRevD.93.075003
 arXiv:
 arXiv:1601.07526
 Bibcode:
 2016PhRvD..93g5003O
 Keywords:

 High Energy Physics  Phenomenology;
 Astrophysics  Cosmology and Nongalactic Astrophysics;
 High Energy Physics  Experiment
 EPrint:
 17 pages, 5 figures, typographical errors corrected