Related papers: S-wave meson scattering up to 2 GeV and its spectr…
The interaction of the pseudoscalar meson and the baryon octet is investigated by solving the Bethe-Salpeter equation in the unitary coupled-channel approximation, In addition to the Weinberg-Tomozawa term, the contribution of the $s-$ and…
We use our latest dispersive analysis of pion-pion scattering data and the very recent Kl4 experimental results to obtain the mass, width and couplings of the two lightest scalar-isoscalar resonances. These parameters are defined from their…
We extract the K+K- couplings of the isoscalar scalar mesons sigma/f_0(600) and f_0(980) from pi pi to pi pi / K K scatterings and found: |g_{sigma K+K-}|/ |g_{sigma pi+pi-}|= 0.8 and |g_{f_0 K+K-}|/ |g_{f_0 pi+pi-}|= 1.7. These results,…
We improve, in the energy region between $\bar{K}K$ threshold and $\sim~1.4$ GeV, the energy-dependent phase shift analysis of $\pi\pi$ scattering presented in a previous paper. For the S0 wave we have included more data above $\bar{K}K$…
In this mini-review I discuss three topics in meson spectroscopy. The production of heavy quarkonium states, S-wave scattering below 1 GeV, and exotic hybrid meson production. This is not intended to be a comprehensive review, just an…
We consider glueball- (hybrid) meson mixing for the low-lying four pseudovector states. The h_1'(1380) decays dominantly to K*K with some presence in rho pi and omega eta. The newly observed h_1(1600) has a D- to S-wave width ratio to omega…
We estimate the I=0 scalar meson $\sigma/f_0(600)$ $\gamma\gamma$ widths, from $\pi\pi$ and $\gamma\gamma$ scattering data below 700 MeV using an improved analytic K-matrix model.
We present the results of energy-dependent and single-energy partial-wave analyses of $\pi$N elastic scattering data with laboratory kinetic energies below 2.1~GeV. Resonance structures have been extracted using Breit-Wigner fits, speed…
In this work we provide simple and precise parameterizations of the existing $\pi K$ scattering data from threshold up to 1.6 GeV, which are constrained to satisfy forward dispersion relations as well as three additional threshold sum…
Lattice gauge calculations predict the existence of glueballs. In particular a scalar glueball is firmly expected at a mass of about 1730 MeV. This prediction has led to an intense study of scalar isoscalar interactions and to the discovery…
Compton scattering off the proton in the third resonance region is analyzed for the first time, owing to the full combined analysis of pion- and photo-induced reactions in a coupled-channel effective Lagrangian model with K-matrix…
Scalar glueball is implemented in single nonet linear sigma model (SNLSM) which basically includes lowest lying scalar and pseudoscalar mesons. Our new version of SNLSM involves mixing among scalar matter fields and glueball field which is…
A production representation of partial-wave $S$ matrix is utilized to construct low-energy elastic pion-nucleon scattering amplitudes from cuts and poles on complex Riemann sheets. Among them, the contribution of left-hand cuts is estimated…
The center-of-gravity rule is tested for heavy and light-quark mesons. In the heavy-meson sector, the rule is excellently satisfied. In the light-quark sector, the rule suggests that the $a_0(980)$ could be the spin-partner of $a_2(1320)$,…
We present exact solutions of two-body problem for spin-1/2 fermions with isotropic spin-orbit(SO) coupling and interacting with an arbitrary short-range potential. We find that in each partial-wave scattering channel, the parametrization…
Motivated by several recent data, we test the QCD spectral sum rules (QSSR) predictions based on different proposals (\bar qq, \bar q\bar q qq, and gluonium) for the nature of scalar mesons. In the I=1 and 1/2 channels, the unusual (wrong)…
The well-known 5-parameter isometry group of plane gravitational waves in $4$ dimensions is identified as Levy-Leblond's Carroll group in $2+1$ dimensions with no rotations. Our clue is that plane waves are Bargmann spaces into which…
Recent data on photoproduction of $\eta'$ mesons off protons have been included in the data base for the Bonn-Gatchina partial wave analysis. The real and imaginary parts of the $S$-wave $\eta^\prime p\to \eta^\prime p$ scattering amplitude…
We present first results on masses of the scalar and tensor glueballs as well as of the torelon from simulations of QCD with two light flavours of Wilson fermions. The gauge configurations of extent 16^3*32 at beta = 5.6 and kappa = 0.156,…
We revisit the information on the two lightest $a_0$ resonances and $S$-wave $\pi\eta$ scattering that can be extracted from photon-photon scattering experiments. For this purpose we construct a model for the $S$-wave photon-photon…