We present two minimal extensions of the standard model, each giving rise to baryogenesis. They include heavy color-triplet scalars interacting with a light Majorana fermion that can be the dark matter (DM) candidate. The electroweak charges of the n
ew scalars govern their couplings to quarks of different chirality, which leads to different collider signals. These models predict monotop events at the LHC and the energy spectrum of decay products of highly polarized top quarks can be used to establish the chiral nature of the interactions involving the heavy scalars and the DM. Detailed simulation of signal and standard model background events is performed, showing that top quark chirality can be distinguished in hadronic and leptonic decays of the top quarks.
We explore the possibility of distinguishing neutrino mass hierarchies through the neutrino signal from dark matter annihilation at neutrino telescopes. We consider a simple extension of the standard model where the neutrino masses and mixing angles
are obtained via the type-II seesaw mechanism as an explicit example. We show that future extensions of IceCube neutrino telescope may detect the neutrino signal from DM annihilation at the Galactic Center and inside the Sun, and differentiate between the normal and inverted mass hierarchies, in this model.
We study the muon $(g-2)_{mu}$ anomaly in light of neutralino dark matter and the LHC. We scan the MSSM parameters relevant to $(g-2)_{mu}$ and focus on three distinct cases with different neutralino compositions. We find that the 2$sigma$ range of $
(g-2)_{mu}$ requires the smuon ($tilde{mu}_1$) to be lighter than $sim$ 500 (1000) GeV for $tan beta=10,(50)$. Correspondingly the two lightest neutralinos, $tilde{chi}_{1}^0, tilde{chi}_{2}^0$, have to be lighter than $sim$ 300 (650) GeV and 900 (1000) GeV respectively. We explore the prospects of searching the light smuon and neutralinos at the LHC, in conjunction with constraints arising from indirect dark matter (DM) detection experiments. The upcoming run of the LHC will be able to set $95%$ CL exclusion limit on $M_{tilde{chi}_{2}^0}$ ($sim 475 - 1300$ GeV) and $m_{tilde{l}}$ ($sim 670-775$ GeV) with $M_{tilde{chi}_{1}^0} sim 100-250$ GeV at 3000 fb$^{-1}$ luminosity in multi-lepton + missing energy channel.
We investigate a potential of discovering lepton flavor violation (LFV) at the Large Hadron Collider. A sizeable LFV in low energy supersymmetry can be induced by massive right-handed neutrinos, which can explain neutrino oscillations via the seesaw
mechanism. We investigate a scenario where the distribution of an invariant mass of two hadronically decaying taus ($tauhtauh$) from $schizero{2}$ decays is the same in events with or without LFV. We first develop a transfer function using this ditau mass distribution to model the shape of the non-LFV $tauhmu$ invariant mass. We then show the feasibility of extracting the LFV $tauhmu$ signal. The proposed technique can also be applied for a LFV $tauh e$ search.
