English

The Other Fermion Compositeness

High Energy Physics - Phenomenology 2017-12-06 v2 High Energy Physics - Theory

Abstract

We discuss the only two viable realizations of fermion compositeness described by a calculable relativistic effective field theory consistent with unitarity, crossing symmetry and analyticity: chiral-compositeness vs goldstino-compositeness. We construct the effective theory of N\mathcal{N} Goldstini and show how the Standard Model can emerge from this dynamics. We present new bounds on either type of compositeness, for quarks and leptons, using dilepton searches at LEP, dijets at the LHC, as well as low-energy observables and precision measurements. Remarkably, a scale of compositeness for Goldstino-like electrons in the 2 TeV range is compatible with present data, and so are Goldstino-like first generation quarks with a compositeness scale in the 10 TeV range. Moreover, assuming maximal RR-symmetry, goldstino-compositeness of both right- and left-handed quarks predicts exotic spin-1/2 colored sextet particles that are potentially within the reach of the LHC.

Keywords

Cite

@article{arxiv.1706.03070,
  title  = {The Other Fermion Compositeness},
  author = {Brando Bellazzini and Francesco Riva and Javi Serra and Francesco Sgarlata},
  journal= {arXiv preprint arXiv:1706.03070},
  year   = {2017}
}

Comments

32 pages on how Thomson might have discovered supersymmetry; v2: few typos fixed and comments added

R2 v1 2026-06-22T20:14:27.701Z