相关论文: Light 2++ and 0++ mesons
The light scalar mesons a_0/f_0(980) are being investigated at COSY-Juelich by detecting the strong decays into K-K-bar and pi-eta/pi-pi as well as radiative decays into vector mesons. Selected results are discussed with emphasis on recent…
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…
Scalar-isoscalar states ($J^{PC}=0^{++}$) are discussed within the large-$N_c$ Regge approach. We find that the lightest $f_0(600)$ scalar-isoscalar state fits very well into the pattern of the radial Regge trajectory where the resonance…
We present results for screening masses of light and strange mesons in 2+1 flavour QCD using improved (p4fat3) staggered fermions on 6x24^3 lattices. We have studied the screening masses of scalar, pseudo-scalar, vector and axial-vector…
We report branching fraction measurements for exclusive decays of charged and neutral B mesons into two-body final states containing a charmonium meson. We use a sample of 22.72 +/- 0.36 million B anti-B events collected between October…
A recent general analysis of light-baryon isospin splittings is updated and extended to charmed baryons. The measured $\Sigma_c$ and $\Xi_c$ splittings stand out as being difficult to understand in terms of two-body forces alone. We also…
The ${q}\bar{q}$ spectrum is studied within a chiral constituent quark model. It provides with a good fit of the available experimental data from light (vector and pseudoscalar) to heavy mesons. The new $D$ states measured at different…
In this paper, we study the spectrum and decay behavior of $5^{++}$ meson family which is still missing in experiment. By the modified Godfrey-Isgur model with a color screening effect, we obtain the mass spectrum of $a_5$, $f_5$ and…
The suggestion by Jaffe that if $\sigma$ is a light $q^{2}\bar{q}^{2}$ state $0^{++}$ then even the fundamental chiral transformation properties of the $\sigma$ becomes {\bf unclear}, has stimulated much interest. Adler pointed out that in…
The flavour and glue structure of the light scalar mesons in QCD are probed by studying the couplings of the I=0 mesons $\sigma(600)$ and $f_0(980)$ to the operators $\bar{q}q$, $\alpha_s G^2$ and to two photons. The Roy dispersive…
Pole trajectories connecting light and heavy scalar mesons, both broad resonances and quasi-bound states, are computed employing a simple coupled-channel model. Instead of varying the coupling constant as in previous work, quark and meson…
We discuss the hadronic molecule issue in the light and heavy meson sector. Thereby we use the radiative decays of the scalars f0(980) and a0(980) to study its possible molecular K barK structure. Further on we extend our formalism to…
The impact a new neutral light particle of spin 0, 1/2, 1, or 3/2 could have on the tiny width of a light Higgs boson is systematically analyzed. To this end, we include all the relevant effective interactions, whether renormalizable or…
By the application of a linear mass spectrum to a composite system of both the pseudoscalar and scalar meson nonets, we find three mass relations for the masses of the scalar states which suggest the $q\bar{q}$ assignment for the scalar…
This report attempts to summarize the most interesting (and hopefully important) results leading up to and including those presented at the recent Symposium sponsored jointly by the Institute of Quantum Science at Nihon University and KEK.…
We discuss the effect of the instanton induced, six-fermion effective Lagrangian on the decays of the lightest scalar mesons in the diquark--antidiquark picture. This addition allows for a remarkably good description of light scalar meson…
The BaBar experiment and the PEP-II accelerator at SLAC started to take data on May 26, 1999. By the time of this conference, the recorded integrated luminosity was 20 fb^{-1}, of which 8 fb^{-1} were analyzed to provide a first set of…
Many measurements of pseudoscalar mesons with S = 0 photoproduced on the proton have been made recently. These new data are particularly useful in theoretical investigations of nucleon resonances. How the new data from various labs…
We address the question whether the lightest scalar mesons sigma and kappa are tetraquarks, as is strongly supported by many phenomenological studies. We present a search for possible light tetraquark states with J^PC=0^++ and I=0, 1/2,…
We calculate the masses and decay constants of the light tensor mesons with quantum numbers $J^P =2^+$ in the framework of the QCD sum rules in the standard model. The non-perturbative contributions up to dimension-$5$ as important terms of…