Related papers: A Theory of Scalar Mesons
The addition of gauge singlet fermions to the Standard Model Lagrangian renders the neutrinos massive and allows one to explain all that is experimentally known about neutrino masses and lepton mixing. At the same time, the gauge singlet…
We consider the collider phenomenology of a singlet Majoron model with softly broken lepton number. Lepton number is spontaneously broken when the real part of a new singlet scalar develops vacuum expectation value. With the additional soft…
The quark-level linear sigma model is employed to compute a variety of electromagnetic and weak observables of light mesons, including pion and kaon form factors and charge radii, charged-pion polarizabilities, semileptonic weak $K_{\ell3}$…
We analyze quark-mass and $1/N_c$ corrections to all of the radiative transitions between the vector-meson nonet and the pseudoscalar-meson nonet within a chiral effective Lagrangian approach. We perform fits of the available coupling…
I consider a model based on a quark--meson interaction Lagrangian. The transition amplitudes are evaluated by computing diagrams in which heavy and light mesons are attached to quark loops. The light chiral symmetry relations and the heavy…
We discuss scalar mesons properties on the light of chiral dynamics. Considering them as the chiral partners of pseudo-scalar mesons we propose an explanation to their unusual properties based on non-trivial vacuum effects coming from the…
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 review our estimations on the light scalar $\bar{q}q$, $(\bar{q}q')(\bar{q'}q)$ and $\overline{qq'}qq'$ ($q,q'\equiv u,d,s$) states from relativistic Laplace sum rule (LSR) within stability criteria and including higher order…
We first study the charmless two-body $\Lambda_b$ decays with the scalar mesons as the final states and predict that ${\cal B}(\Lambda_b\to \Lambda f_0(980,1500))=(2.9\pm 0.7,12.4\pm 3.8)\times 10^{-6}$ and ${\cal B}(\Lambda_b\to p…
We estimate the decay constants $f_\pi$ and $f_K$ of the light mesons within a relativistic quantum-field model of interacting quarks and gluons confined analytically. The necessary physical parameters, the quark masses $m_u$ and $m_s$, the…
A symmetry-preserving treatment of a vector$\times$vector contact interaction is used to compute spectra of ground-state $J^P = 0^\pm, 1^\pm$ $(f\bar g)$ mesons, their partner diquark correlations, and $J^P=1/2^\pm, 3/2^\pm$ $(fgh)$…
The vast majority of mesons can be understood as quark-antiquark states. Yet, various other possibilities exists: glueballs (bound-state of gluons), hybrids (quark-antiquark plus gluon), and four-quark states (either as diquark-antidiquark…
We show that heavy fermions decouple from the low energy physics also in non-perturbative instanton effects. Provided the heavy fermions are lighter than the symmetry breaking scale, all the instanton effects should be expressed as local…
We present results for the spectrum of light and strange mesons on configurations with two flavors of mass-degenerate Chirally Improved sea quarks. The calculations are performed on seven ensembles of lattice size 16^3x32 at three different…
The Nijmegen Unitarized Meson Model and its application to scalar mesons is briefly revisited. It is shown that all scalar states up to 1.5 GeV can be described as triplet-P-zero quark+antiquark states coupled to the OZI-allowed open and…
Based on the assumption of two-quark structure for the light scalar mesons, within the framework of perturbative QCD approach, we investigate the $B_{q}\to D_{(s)}^{(*)} S(q=u,d,s)$ decays induced by $b\to u $ transition, where $S$ denotes…
I give a brief introduction to light $q\bar{q}$ resonances. The properties of $q\bar{q}$ states are discussed in the context of the constituent quark model, including predictions for mass and partial decay widths. Problems and puzzles in…
Two-body bound states such as mesons are described by solutions of the Bethe-Salpeter equation. We discuss recent results for the pseudoscalar and vector meson masses and leptonic decay constants, ranging from pions up to c\bar{c} bound…
The scalar contributions to the radiative decays of light vector mesons into a pair of neutral pseudoscalars, $V\to P^0P^0\gamma$, are studied within the framework of the Linear Sigma Model. This model has the advantage of incorporating not…
We compute pseudoscalar meson masses and decay constants using staggered quarks on lattices with three flavors of sea quarks and lattice spacings $\approx 0.12$ fm and $\approx 0.09$ fm. We fit partially quenched results to ``staggered…