From flavor puzzles to new dynamics

Particle Physics Theory seminar

From flavor puzzles to new dynamics

  • Event time: 2:00pm
  • Event date: 18th April 2018
  • Speaker: Christopher Smith (Laboratory of subatomic Physics & Cosmology, Universit√© Grenoble Alpes)
  • Location: Higgs Centre Seminar Room, Room 4305,

Event details

A particularly puzzling feature of the SM is its flavor sector. It is the least constrained theoretically, accounting for about two-third of the SM free parameters. At the same time, the measured values of the quark and lepton masses and mixings show peculiar hierarchies, and hint at some yet unknown organizing principle. Phenomenologically, in the absence of this full theory of flavor, most New Physics models have no reason to preserve the SM flavor hierarchies and the associated accidental or approximate symmetries. As a result, they end up seriously constrained by flavor observables, and their typical scale are often pushed well beyond the reach of the LHC.

In this talk, our goal will be to show that the peculiar hierarchies exhibited in the SM, instead of hindering the presence of New Physics at the TeV scale, could actually point towards specific new dynamics. We will discuss two examples. First, we will detail the possibility of TeV-scale baryon number violating processes, which in a supersymmetric context could explain the current absence of New Physics signals at the LHC. Then, we will turn to the unification of quarks and leptons. We will describe a mechanism by which the large top quark mass can render its third-generation leptonic partner very light. This state is thus identified with the electron. We will then show how to implement dynamically this mechanism, using tree-level exchanges of TeV-scale vector leptons to relate the quark and charged lepton flavor structures.

Event resources

About Particle Physics Theory seminars

The Particle Physics Theory seminar is a weekly series of talks reflecting the diverse interests of the group. Topics include analytic and numerical calculations based on the Standard Model of elementary particle physics, theories exploring new physics, as well as more formal developments in gauge theories and gravity..

Find out more about Particle Physics Theory seminars.