Precision measurements of the properties of the discovered Higgs boson are one of the main programs at current and future collider experiments. At the international linear collider with the center-of-mass energy 250 GeV, e+e- → hZ is the dominant Higgs production process, and the cross section would be measured with a few percent accuracies. In this talk, we present the cross section of the...
We consider the renormalizable leptophilic WIMP models with the scalar mediators which have lepton numbers. We perform a comprehensive analysis for such a WIMP scenario for two distinct cases with SU(2) doublet or singlet mediators considering all the relevant theoretical, cosmological and experimental constraints at present. We show that mono-photon search at ILC experiment can play a...
Large fermionic multiplets appear in different extensions of the Standard Model, which are essential to predict small neutrino masses, relic abundance of the dark matter and the measured value of muon anomalous magnetic moment. Such models may contain quintuplet of fermions along with scalar multiplets. If the quintuplet fermions (doubly and singly charged fermions, neutral fermion) are...
"The direct pair-production of the tau-lepton superpartner, stau, is one
of the most interesting channels to search for SUSY. First of all the stau is
with high probability the lightest of the scalar leptons. Secondly the
signature of stau pair production signal events is one of the most difficult
ones, yielding to the 'worst' and so most global scenario for the searches.
The current...
One of the primary goals of the proposed future collider experiments is to search for dark matter (DM) particles using different experimental approaches. High energy e+e- colliders offer unique possibility for the most general search based on the mono-photon signature. As any e+e- scattering process can be accompanied by a hard photon emission from the initial state radiation, analysis of the...
Supersymmetry offers a portal to study neutrino physics via sneutrinos. I shall discuss a signature that can be only detected at an electron-positron collider, namely the production of a charged higgsino pair, one of them subsequently decaying to a charged lepton and a right-sneutrino LSP. This decay is rare, with a branching ratio O(10^-5) and hence the clean environment and fixed partonic...
Axion and axion-like particles (ALPs) are attractive candidates of light dark matter (DM). They emerge as a pseudo-Nambu Goldstone boson in spontaneously breaking of global U(1) symmetry in the dark sector. The mass is obtained by the explicit breaking of the U(1). In many new physics models, it is usually assumed that the dark sector, in which axion/ALP exists, is CP conserving. In contrast...
I report on studies and possible BSM scenarios with (Higgs) scalars of masses < 125 GeV. This talk is based on similar overview talks at the CEPC/ FCC workshops within the last half year, and is tailored be used as a foundation for a Snowmass White Paper on this topic.
Our current understanding of string theory is that the 4-d laws of physics are determined by the topological properties of the compactified manifold. There may be 10^500 (or many more) possibilities, and indeed this gives at present our only understanding of the tiny yet non-zero value of the cosmological constant. Arguments suggest the landscape of string vacua favor large soft SUSY breaking...
