Horizontal Gauge Symmetry?

Question

Some physics literature says Horizontal Symmetry of gauge theory, such as this paper, available also at arXiv.

What does this Horizontal Symmetry of gauge theory or Horizontal gauge group mean? Does that mean the symmetry group in the same energy scale (horizontal, not go up or down of an energy scale)?

People speak about the Horizontal Symmetry, such as in the Symmetry for 3 family of leptons and quarks.

This post imported from StackExchange Physics at 2020-12-03 13:05 (UTC), posted by SE-user annie marie heart

Comments

This may be related physics.stackexchange.com/q/206521/42982 but not enough to answer fully

This post imported from StackExchange Physics at 2020-12-03 13:05 (UTC), posted by SE-user annie marie heart

Answer 1

Horizontal symmetries or family symmetries are various discrete, global, or local symmetries between (three) families or generations of quarks and leptons in particle physics.

See References in https://en.wikipedia.org/wiki/Family_symmetries.

Horizontal gauge symmetries would be Horizontal symmetries that are local and gauged.

This post imported from StackExchange Physics at 2020-12-03 13:05 (UTC), posted by SE-user wonderich

Comments

I hope there is a better answer, thanks. But I can accept it if no more better answers.

This post imported from StackExchange Physics at 2020-12-03 13:05 (UTC), posted by SE-user annie marie heart