Related papers: Some Developments in Light Quark Spectroscopy
In light of recent LHC results for the extraction of the $B_s$ mixing phase $\phi_s$, we can already conclude that if New Physics (NP) is present in this observable, it is hiding pretty well. Thus, as our hunt continues, we must be weary…
In the SU(3) symmetry limit, the ratio $R\equiv\frac{{\cal B}(D^+\to f_0l^+\nu)+ {\cal B}(D^+\to \sigma l^+\nu)}{{\cal B}(D^+\to a_0^0l^+\nu)}$ is equal to 1 if the scalar mesons are $\bar qq$ states, while it is 3 if these mesons are…
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 paper we present an approach to study the radiative decay modes of the $J/\psi$ into a photon and one of the tensor mesons $f_2(1270)$, $f'_2(1525)$, as well as the scalar ones $f_0(1370)$ and $f_0(1710)$. Especially we compare…
We show on gauge invariance grounds that the fine threshold phenomenon is discovered in the radiative decays phi->gamma a0->gamma pi0 eta and phi->gamma f0->gamma pi0pi0. This enables to conclude that production of the lightest scalar…
The radiative decays of the B mesons may have a significant contribution from the transition b -> s J/psi followed by the J/psi-photon conversion. The size of this contribution is re-analysed in the light of a phenomenological model for the…
We continue the investigation of mesons in terms of the spectral integral equation initiated before [hep-ph/0510410, hep-ph/0511005] for the $b\bar b$ and $c\bar c$ systems: in this paper we consider the light-quark ($u, d,s$) mesons with…
A coupled channel model is used to study the nature of the scalar mesons produced in the decay phi - gamma pi pi. The KKbar molecular picture of f0(980) is found to be in a good agreement with the recent experimental data from SND and…
Outline: 1. Introduction, 2. Confinement, chiral dynamics and light scalar mesons, 3. Chiral shielding of the \sigma(600), chiral constraints (the CGL band), the \sigma(600) and the f0(980) in \pi\pi->\pi\pi, \pi\pi->KKbar,…
We review here the physics of purely leptonic decays of pi-, K-, D+, Ds+, and B- pseudoscalar mesons. The measured decay rates are related to the product of the relevant weak interaction based CKM matrix element of the constituent quarks…
The ongoing and planned experimental activities with direct reference to light unflavoured pseudoscalar mesons motivate a new theoretical study regarding their properties. An overview including details on new precise calculations is…
Light bosons can be found in large classes of theories beyond the Standard Model. These light bosons may not be ruled out by current experiments and, indeed, may even provide an explanation for some anomalous experimental results. The…
With the primary motivation of probing the quark substructure of scalar mesons, a generalized linear sigma model for the lowest and the next-to-lowest scalar and pseudoscalar mesons is employed to investigate several semi-leptonic decays of…
The light-quark non-strange scalar mesons a0(980), f0(980), f0(1370), a0(1450), f0(1500) and f0(1710) are of great interest as there is no generally accepted view of their structure which can encompass q-q-qbar-qbar, molecular, q-qbar and…
The light scalar mesons in a variety of approaches are briefly reviewed, as well as their description in the Resonance-Spectrum Expansion and related coupled-channel formalisms. A recent multichannel modelling of the light scalars is…
We present an update of the MILC investigation of the properties of light pseudoscalar mesons using three flavors of improved staggered quarks. Results are presented for the $\pi$ and $K$ leptonic decay constants, the CKM matrix element…
The scalar glueball is observed in a coupled-channel analysis of the $S$-wave amplitude from BESIII data on radiative $J/\psi$ decays and further data. Ten scalar isoscalar resonances were required to fit the data. Five of them were…
The Standard Model has achieved significant success in particle physics; however, there are still some unresolved puzzles beyond it. This motivates the exploration of the dark sector. We present the recent dark sector search results from…
Using 6.32~fb$^{-1}$ of $e^+e^-$ collision data recorded by the BESIII detector at center-of-mass energies between $4.178$ to $4.226$ GeV, we present the first measurement of the decay $D_s^+\to f_0(980)e^+\nu_e,\,f_0(980)\to \pi^0\pi^0$.…
We estimate the rates for radiative transitions of the lightest scalar mesons f_0(980) and a_0(980) to the vector mesons rho and omega. We argue that measurements of the radiative decays of those scalar mesons can provide important new…