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Flavor Puzzle

Why care?

“In a recent interview published in CERN COURIER, Steven Weinberg was asked what single open question he would like to see answered in his lifetime, and Weinberg replied that it is only the mystery of the observed pattern of quark and lepton masses[1]. ”

Good Reviews

Puzzle Pieces

  • Hierarchy between generations
  • Hierarchy within each generation
    • Especially anomaly of the sign of the mass difference between the u and d. (t-b>0,c-s>0, but u-d<0)
    • Plus while at GUT scale, tau = bottom works, for the other generations we need 3ms= mu and md = 3me; superold relations, no clue how valid they are today. (source: Mass and mixing angle patterns in the standard model, Ramond)
  • Mixing within each generation
  • Why 3 generations at all
  • Why these particles in each generation


Ideas for specific Puzzle Pieces

  • Hierarchy between generations
    • Loops! “One possibility is that only one fermion or family of fermions get mass from the large scale physics, while the physics at intermediate scales allows mass to cascade down from one family to the next, each time suppressed by a power of some small parameter (such as a gauge coupling constant). This idea has a long history, going back to attempts to relate the electron-muon mass ratio to the electromagnetic coupling [ 1 ] . It still looks attractive because it could explain the apparently hierarchical nature of the flavor masses. Nevertheless, it has not led to any convincing results for the mass matrices” see Light Fermion Mass Hierarchy and Grand Unification Stephen M. Barr
    • Fermion Mass Hierarchy from Radiative Corrections B. S. Balakrishna No horizontal symmetry!
    • If mass matrix antisymmetric, one generation massless!
  • Hierarchy within each generation
    • RGE running PLUS ???
  • Mixing within each generation
    • Flavor Blind Principle → works at z-scale, but angels do not run and ratios are different at the GUT scale. Symmetries are caused by things not the cause of things. That’s why flavor blind principle instead of ad how symmetry. Follows if everything is unified.
  • Why 3 generations at all
    • 3 generations because of 3 spatial dimensions → correspond to different shapes, instead of point particles (Goldhaber “Why are there three generations of particles?” in Gift of Prophecy book)
flavor_puzzle.txt · Last modified: 2018/01/29 13:02 by jakobadmin