Title: Three Extra Mirror or Sequential Families: a Case for Heavy Higgs and Inert Doublet Authors: Homero Martínez, Alejandra Melfo, Fabrizio Nesti, Goran Senjanovi
We study the possibility of the existence of extra fermion families and an extra Higgs doublet. We find that requiring the extra Higgs doublet to be inert leaves ample space for three extra families and marginally accommodates four, allowing for mirror fermion families and a dark matter candidate at the same time. The emerging scenario is very predictive: it consists of a heavy Standard Model Higgs, with mass above 450 GeV, heavy new quarks between 340 and 400 GeV, light extra neutral leptons, and an inert scalar with a mass below MZ
For decades physicists have been fascinated and frustrated by "heavy fermions" -- electrons that move through a conductor as if their mass were up to 1,000 times what it should be. Now for the first time scientists have produced images of heavy fermion behaviour and resolved a theoretical question about its cause. Using an incredibly sensitive scanning tunnelling microscope (STM) and a technique called "spectroscopic imaging" that measures the energy levels of electrons under the STM probe, a team led by J.C. Séamus Davis, the James Gilbert White Distinguished Professor in the Physical Sciences at Cornell and director of the Centre for Emergent Superconductivity at Brookhaven National Laboratory, determined that electrons moving through a particular uranium compound appear "heavy" because their motion is constantly interrupted by interaction with the uranium atoms. Read more