Shao-Feng Ge

Realizing dark matter and Higgs inflation in light of LHC diphoton excess

Abstract LHC Run-2 has provided intriguing di-photon signals of a new resonance around 750 GeV , which, if not due to statistical fluctuations, must call for new physics beyond the standard model (SM) at TeV scale. We propose a minimal extension of the SM with a complex singlet scalar S and a doublet of vector-like quarks. The scalar sector respects CP symmetry, with its CP-odd imaginary component χ providing a natural dark matter (DM) candidate. The real component of S serves as the new resonance ( 750 GeV ) and explains the diphoton excess of the LHC Run-2. The new scalar degrees of freedom of S help to stabilize the Higgs vacuum, and can realize the Higgs inflation around GUT scale, consistent with the current cosmological observations. We construct two representative samples A and B of our model for demonstration. We study the mono-jet signals of DM production from invisible decays Re ( S ) → χ χ at the LHC Run-2. We further derive the DM relic density bound, and analyze constraints from the direct and indirect DM detections.

Probing new physics scales from Higgs and electroweak observables at e + e − Higgs factory

A bstractNew physics beyond the standard model (SM) can be model-independently formulated via dimension-6 effective operators, whose coefficients (cutoffs) characterize the scales of new physics. We study the probe of new physics scales from the electroweak precision observables (EWPO) and the Higgs observables (HO) at the future e+e− Higgs factory (such as CEPC). To optimize constraints of new physics from all available observables, we establish a scheme-independent approach. With this formulation, we treat the SM electroweak parameters and the coefficients of dimension-6 operators on equal footing, which can be fitted simultaneously by the same χ2 function. As deviations from the SM are generally small, we can expand the new physics parameters up to linear order and perform an analytical χ2 fit to derive the potential reach of the new physics scales. We find that the HO from both Higgs produnction and decay rates can probe the new physics scales up to 10 TeV (and to 44 TeV for the case of gluon-involved operator Og

New physics effects on neutrinoless double beta decay from right-handed current

{mathcal{O}}_g

Non-standard interactions and the CP phase measurements in neutrino oscillations at low energies

), and the new physics scales of Yukawa-type operators can be probed by the precision Higgs coupling measurements up to (13 − 25) TeV. Further including the EWPO can push the limit up to 35 TeV. From this prospect, we demonstrate that the EWPO measured in the early phase of a Higgs factory can be as important as the Higgs observables. These indirect probes of new physics scales at the Higgs factory can mainly cover the energy range to be directly explored by the next generation hadron colliders of pp (50 −100 TeV), such as the SPPC and FCC-hh.

Atmospheric trident production for probing new physics

Non-unitary neutrino mixing implies an extra CP violating phase that can fake the leptonic Dirac CP phase

Extracting Majorana properties from strong bounds on neutrinoless double beta decay

delta_{CP}

The Georgi algorithms of jet clustering

of the simplest three-neutrino mixing benchmark scheme. This would hinder the possibility of probing for CP violation in accelerator-type experiments. We take T2K and T2HK as examples to demonstrate the degeneracy between the standard (or unitary) and non-unitary CP phases. We find, under the assumption of non-unitary mixing, that their CP sensitivities severely deteriorate. Fortunately, the TNT2K proposal of supplementing T2(H)K with a

JUNO and Neutrinoless Double Beta Decay

mu