Related papers: A new perspective on the $\Delta_{5/2^{+}}(2000)$ …
I summarize the status of the $\Delta I=1/2$ rule in $K\to\pi\pi$ decays within an {\it analytic} approach based on the dual representation of QCD as a theory of weakly interacting mesons for large $N$, where $N$ is the number of colours.…
We have searched for bound states in the pion-Lambda-nucleon system by solving the nonrelativistic Faddeev equations, as well as a relativistic version, with input separable pion-nucleon, pion-Lambda, and Lambda-nucleon interactions. A…
We implement a convolutional neural network to study the $\Sigma$ hyperons using experimental data of the $K^-p\to\pi^0\Lambda$ reaction. The averaged accuracy of the NN models in resolving resonances on the test data sets is ${\rm…
We solve the Faddeev equations for the two meson-one baryon system $\pi\pi N$ and coupled channels using the experimental two-body $t$-matrices for the $\pi N$ interaction as input and unitary chiral dynamics to describe the interaction…
We present parametrizations of the $\gamma^\ast N \to N(1535)1/2^-$, $\gamma^\ast N \to N(1520)3/2^-$ and $\gamma^\ast N \to \Delta(1232)3/2^+$ transition amplitudes that are compatible with the analytic constraints at the pseudothreshold…
The one-dimensional Schr\"odinger equation with the point potential in the form of the derivative of Dirac's delta function, $\lambda \delta'(x)$ with $\lambda$ being a coupling constant, is investigated. This equation is known to require…
Born cross sections for the processes $e^+e^- \to \omega\eta$ and $e^+e^- \to \omega\pi^{0}$ have been determined for center-of-mass energies between 2.00 and 3.08 GeV with the BESIII detector at the BEPCII collider. The results obtained in…
In this paper we prove a Pohozaev-type identity for both the problem $(-\Delta+m^2)^su=f(u)$ in $\mathbb{R}^N$ and its harmonic extension to $\mathbb{R}^{N+1}_+$ when $0<s<1$. So, our setting includes the pseudo-relativistic operator…
Two reactions, pp->ppX and pp->p\pi^+X, are used to study the 1.47<M<1.68 GeV baryonic mass range. Three different final states are considered in the invariant masses: N^* or \Delta^+, p\pi^0, and p\eta. The last two channels are defined by…
The electroexcitation amplitudes or $\gamma_vpN^*$ electrocouplings of the $N(1440)1/2^+$, $N(1520)3/2^-$, and $\Delta(1600)3/2^+$ resonances were obtained for the first time from the $ep \to e'\pi^+\pi^-p'$ differential cross sections…
In the reactions $p\bar p\to\pi^0\pi^0,\eta\eta,\eta\eta'$ there are four relatively narrow resonances $f_2(1920)$, $f_2(2020)$, $f_2(2240)$, $f_2(2300)$, and a broad one $f_2(2000)$ in the mass region 1990--2400 MeV. In the framework of…
We calculate the correlation functions for the $\bar K^0 p, \pi^+ \Sigma^0, \pi^0 \Sigma^+, \pi^+ \Lambda$, and $\eta \Sigma^+$ states, which in the chiral unitary approach predict an excited $\Sigma^*(1/2^-)$ state at the $\bar K N$…
The differential cross section for the reaction $^{12}$C$(\gamma ,\pi ^{+}p)$ has been measured in the $\Delta$ resonance region at high recoil momenta of the residual nuclear system. The data are analysed under the assumption that the…
The identification of problematic meson states as the members of the quark model $q\bar{q}$ nonets by using a hadronic resonance spectrum is discussed. The results favor the currently adopted $q\bar{q}$ assignments for the axial-vector,…
JLab has recently found indications of the possible existence of a $\Sigma NN$ resonance at $(3.14 \pm 0.84) - i (2.28 \pm 1.2)$ MeV. In the past, using models that exploit symmetries between the two-baryon sector with and without…
Using 13.5 fb^{-1} of e^+e^- annihilation data collected with the CLEO-II detector, we have observed a new narrow resonance in the D_s^*\pi^0 final state, with a mass near 2.46 GeV/c^2. The search for such a state was motivated by the…
The article contains new results for spin-3/2 and -1/2 resonances. It specializes to the second resonance region, which includes the $P_{11}(1440)$, $D_{13}(1520)$ and $S_{11}(1535)$ resonances. New data on electroproduction enable us to…
We deal with the problem of existence of periodic solutions for the scalar differential equation x" + f (t, x) = 0 when the asymmetric nonlinearity satisfies a one-sided superlinear growth at infinity. The nonlinearity is asked to be next…
The differential cross section for the $^{12}$C$(\gamma,\pi^{+}p)$ reaction has been measured in the $\Delta$(1232) resonance region at high recoil momenta of the residual nuclear system. The data are analyzed under the assumption that the…
In a previous work regarding the interaction of two $\rho(770)$ resonances, the $f_2(1270)$ ($J^{PC}=2^{++}$) resonance was obtained dynamically as a two-$\rho$ molecule with a very strong binding energy, 135~MeV per $\rho$ particle. In the…