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

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 γγ, γZ 0 , W + W − , Z 0 Z 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 W W , W Z 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.

Shedding new light on sterile neutrinos from XENON1T experiment

“…shows interactions between different flavour families through the charged current channel, for example N e R − τ R . This in fact gives the flavour oscillations of the sterile neutrinos [93]. The mixing matrix…”

“…On the other hand, the theoretical inconsistency [87][88][89][90] between the SM bilinear Lagrangian of the chiral gauged fermions and the natural UV cutoff of unknown dynamics or quantum gravity requires that an effective field theory possesses quadrilinear four-fermion interactions (operators) of the Nambu-Jona-Lasinio (NJL) type [91] at high-energy scales. On the basis of only SM gauge symmetries, four-fermion operators of SM left-and righthanded fermions (ψ L , ψ R ) in the charge sector "Q" and flavor family "f " are introduced [53,54,[92][93][94][95][96]…”

“…There are two fixed points (scaling domains) for the effective coupling G in (2.1). One is the strong coupling ultraviolet (UV) fixed point at characteristic energy TeV, where SM gauge symmetries are preserved by composite particles [93]. A phenomenological study of such composite particles at the LHC is recently presented in [97].…”

“…In such a scenario, four-fermion operators of eq. (2.1) induce right-handed current couplings [92][93][94]. We do not need to add any fiducial beyond the SM gauge boson, such as W R , W , Z or light particles, except right-hand neutrinos.…”

Diphoton resonances at the LHC

“…Models of new physics beyond the SM to which our analysis applies include, for example, theories of minimal composite dynamics [5][6][7][8][9][10][11][12], where X is a composite pseudoscalar state, analogous to the η or the η in QCD, and theories with axion-like particles (see, e.g., [13] and references therein). Similar constraints in the diphoton channel apply to scenarios which predict spin-2 resonances coupled to photons, such as the graviton in Randall-Sundrum models [14] or spin-0 radion/dilaton particles [15][16][17][18][19][20][21].…”