An effective strong-coupling theory of composite particles in UV-domain

TL;DR

This paper develops an effective field theory for massive composite particles at a UV-stable fixed point, analyzing their decay channels into Standard Model particles and exploring experimental and cosmic implications.

Contribution

It introduces a strong-coupling theory of composite particles in the UV domain, detailing decay rates and potential experimental signatures beyond the Standard Model.

Findings

Calculated decay rates of composite bosons into gauge boson pairs.

Identified unique kinematic signatures of composite fermion decays.

Discussed cosmic ray and underground detection implications.

Abstract

We briefly review the effective field theory of massive composite particles, their gauge couplings and characteristic energy scale in the UV-domain of UV-stable fixed point of strong four-fermion coupling, then mainly focus the discussions on the decay channels of composite particles into the final states of the SM gauge bosons, leptons and quarks. We calculate the rates of composite bosons decaying into two gauge bosons $\gamma\gamma$, $\gamma Z^0$, $W^+W^-$, $Z^0Z^0$ and give the ratios of decay rates of different channels depending on gauge couplings only. It is shown that a composite fermion decays into an elementary fermion and a composite boson, the latter being an intermediate state decays into two gauge bosons, leading to a peculiar kinematics of final states of a quark (or a lepton) and two gauge bosons. These provide experimental implications of such an effective theory of composite particles beyond the SM. We also present some speculative discussions on the channels of composite fermions decaying into $WW$, $WZ$ and $ZZ$ two boson-tagged jets with quark jets, or to four-quark jets. Moreover, at the same energy scale of composite particles produced in high-energy experiments, composite particles are also produced by high-energy sterile neutrino (dark matter) collisions, their decays lead to excesses of cosmic ray particles in space and signals of SM particles in underground laboratories.