# The other effective fermion compositeness

Journal of High Energy Physics, Nov 2017

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 $\mathcal{N}$ 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 R-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.

This is a preview of a remote PDF: https://link.springer.com/content/pdf/10.1007%2FJHEP11%282017%29020.pdf

Brando Bellazzini, Francesco Riva, Javi Serra, Francesco Sgarlata. The other effective fermion compositeness, Journal of High Energy Physics, 2017, 20, DOI: 10.1007/JHEP11(2017)020