New physics for muon anomalous magnetic moment and its electroweak precision analysis

About 3 sigma deviation from the standard model prediction of muon anomalous magnetic moment (muon g-2) has been reported. We consider new physics beyond the standard model which has new Yukawa interactions with muon. We compute new contributions to muon g-2 and corrections to electroweak observables, and show the consistent region of parameter space. We find that in a simple model where the chirality flip of muon occurs only in the external muon line in one-loop muon g-2 diagrams, it is necessary to introduce the relatively large new Yukawa coupling and the electroweak scale new particles. On the other hand, in a model where the chirality flip can occur in the internal fermion line of one loop muon g-2 diagrams, we can obtain favorable g-2 contributions without large Yukawa coupling, and they are consistent with the precision electroweak observables. Finally, we discuss effects of new particles for muon g-2 on the Higgs boson decay h to 2 photons and direct productions of these particles at the LHC experiment.Comment: 31 pages, 20 figure

Trion dynamics in lead halide perovskite nanocrystals

Metal halide perovskite semiconductors fabricated with simple low-temperature solution processes are a unique class of materials anticipated for use in photonic devices such as solar cells, light-emitting diodes, and light modulators. The metal halide perovskites in the form of nanocrystals are particularly attracting attention as novel functional materials because of their exceptionally high luminescence efficiencies and wide range of possible luminescence wavelengths. By combining different optical characterization techniques, that is, single-dot spectroscopy, photon correlation spectroscopy, femtosecond transient absorption spectroscopy, and time-resolved photoluminescence spectroscopy, we study the dynamics of excitons, trions, and biexcitons in perovskite nanocrystals. Here, we provide a concise review of recent developments in this research field with a focus on trions in lead halide perovskite nanocrystals. A deep understanding of trion dynamics is especially important because they determine the luminescence properties of nanocrystals and are related to the ionization processes of nanocrystals