Related papers: Light $O^{++}$ Mesons: Scalargators in Florida
We consider conformal transitions arising from the merging of IR and UV fixed points, expected to occur in QCD with a large enough number of flavors. We study the smoothness of physical quantities across this transition, being mostly…
We present recent results on light mesons based on Dalitz plot analyses of charm decays from Fermilab experiment E791. Scalar mesons are found to have large contributions to the decays studied, $D^+\to K^-\pi^+\pi^+$ and $D^+,…
We study a scenario in which the only light new particles are a Majorana fermion dark matter candidate and one or more QCD-charged scalars, which couple to light quarks. This scenario has several interesting phenomenological features if the…
The nature of low-lying scalar and axial-vector charmed mesons has long been debated, specifically whether they are best explained as hadronic molecules or compact tetraquark systems. These two scenarios exhibit quite different features for…
Among the many unresolved questions in light quark spectroscopy, the underlying structure of the scalar mesons and the identification of states with a gluonic content rank high. Recently, new information has come from $\phi$ radiative…
This talk is a brief account of recent developments on light scalar meson spectroscopy. I mostly focus on the major revision of the $\sigma$ or $f_0(500)$ meson in the Review of Particle Physics, driven by new data and the accummulation of…
The contributions of scalar leptoquarks in lepton flavor violating (LFV) processes of type $l_i\to l_j \gamma$ are investigated in frame of the minimal model with the four color symmetry and Higgs mechanism of quark and lepton mass…
The simplest extension of the standard model consists in adding one singlet scalar field which mixes with the Higgs boson. O(GeV) masses of the new scalar carry strong motivation from relaxion, dark matter and inflation models. The decay of…
We introduce a new symmetry-preserving framework for the physics of heavy-light mesons, whose key element is the effective incorporation of flavour-dependent contributions into the corresponding bound-state and quark gap equations. These…
We report on first results of an ongoing effort to simulate lattice QCD with two degenerate flavours of quarks by means of the twisted mass formulation tuned to maximal twist. By utilising recent improvements of the HMC algorithm,…
A short review on light scalar mesons is performed both in experiment and theory. A naive model, constrained by D branching ratios, is derived in order to make predictions on the wave functions of the $f_0(600)$ and $a_0(980)$ mesons. This…
In this write-up, we summarize our recent analysis of radiative decays involving light scalar mesons. Our analysis using the vector meson dominance model at tree level indicates that it may be difficult to distinguish $qq\bar{q}\bar{q}$…
In a relativistic quark model with linear confinement and an instanton-induced interaction which solves the $\eta$-$\eta'$ puzzle, scalar mesons are found as almost pure SU(3) flavor states. This suggests a new interpretation of the scalar…
Anisotropic lattices are an efficient means of studying the glueballs of QCD, however problems arise with simulations of the lightest, scalar state. The mass is strongly dependent on the lattice spacing, even when a mean-field improved…
The lattice QCD results on the hadron spectrum and weak transitions between hadrons are briefly reviewed. Hadrons containing heavy quarks c or b are considered. The focus is on the recent simulations and some older results which are…
We construct a relativistic $^3P_0$ wavefunction for scalar mesons within the framework of light-front quark model(LFQM). This scalar wavefunction is used to perform relativistic calculations of absolute widths for the radiative decay…
We summarize some persistent problems in scalar spectroscopy and discuss what could be learned here from charmless B-decays. Recent experimental results are discussed in comparison with theoretical expectations: a simple model based on…
We introduce an effective lagrangian including negative and positive parity heavy mesons containing a heavy quark, light pseudoscalars, and light vector resonances, with their allowed interactions, using heavy quark spin-flavour symmetry,…
We consider weak decays of heavy hadrons (bottom and charmed) where the heavy quark acts as a spectator. Theses decays are heavily phase-space suppressed but may become experimentally accessible in the near future. These decays are…
We use the QCD instanton vacuum model to discuss the emergence of the light scalar and vector mesons on the light front. We take into account both the instanton and anti-instanton single and molecular interactions on the light quarks, in…