Scale anomaly and the scalars

Glueball Dark Matter Revisited

We revisit the possibility that dark matter is composed of stable scalar glueballs of a confining dark SU(3) gauge theory coupled only to gravity. The relic abundance of dark glueballs is studied for the first time in a thermal effective theory accounting for strong-coupling dynamics. An important ingredient of our analysis is the use of an effective potential for glueballs that is fitted by lattice simulations. We predict the relic abundance to be in the range 0.12ζ_{T}^{-3}Λ/(137.9  eV)≲Ωh^{2}≲0.12ζ_{T}^{-3}Λ/(82.7  eV), with Λ being the confinement scale, ζ_{T} the visible-to-dark sector temperature ratio, and the uncertainty is coming from the fit to lattice data. This prediction is an order of magnitude smaller than the existing glueball abundance results in the literature. Our framework can be easily generalized to different gauge groups and modified cosmological histories paving the way toward consistent exploration of strongly coupled dark sectors and their cosmological implications.

Excited scalar and pseudoscalar mesons in the extended linear sigma model

We present an in-depth study of masses and decays of excited scalar and pseudoscalar [Formula: see text] states in the Extended Linear Sigma Model (eLSM). The model also contains ground-state scalar, pseudoscalar, vector and axial-vector mesons. The main objective is to study the consequences of the hypothesis that the [Formula: see text] resonance, observed a decade ago by the BES Collaboration and recently by LHCb, represents an excited scalar quarkonium. In addition we also analyse the possibility that the new [Formula: see text] resonance, observed recently by BABAR, may also be an excited scalar state. Both hypotheses receive justification in our approach although there appears to be some tension between the simultaneous interpretation of [Formula: see text]/[Formula: see text] and pseudoscalar mesons [Formula: see text], [Formula: see text], [Formula: see text] and K(1460) as excited [Formula: see text] states.