Related papers: Transition from resonances to surface waves in pi^…
We present an investigation of pion-nucleon elastic scattering in the $I\,(J^P) = \frac{3}{2}\,(\frac{3}{2}^+)$ channel using lattice QCD with degenerate up and down, strange and charm quarks with masses tuned to their physical values. We…
The existence of a neutron scattering resonance at a wavevector q* implies a sign change of the gap between two Fermi surface regions separated by wavevector q* . For the Fe pnictides, a resonance has been observed for a wavevector q* which…
In the present article the classical problem of electromagnetic scattering by a single homogeneous sphere is revisited. Main focus is the study of the scattering behavior as a function of the material contrast and the size parameters for…
In this work we present a determination of the mass, width and coupling of the resonances that appear in kaon-pion scattering below 1.8 GeV. These are: the much debated scalar $\kappa$-meson, nowdays known as $K_0^*(800)$, the scalar…
In general, discrete eigenstates such as resonances are represented by poles of the scattering amplitude, analytically continued to the complex energy plane. In multi-channel scattering, however, the Riemann surface becomes more…
We perform a rigorous analysis of the $\pi K$ scattering at an unphysical pion mass 391 MeV using the Roy-Steiner equations, which satisfy unitarity, analyticity and crossing symmetry, for the first time. Stable solutions of the Roy-Steiner…
We determine the energy-dependent amplitude for elastic {\pi}{\pi} P-wave scattering in isospin-1 by computing part of the discrete energy spectrum of QCD in finite cubic boxes. We observe a rapidly rising phase shift that can be well…
Exclusive and kinematically complete high-statistics measurements of quasifree polarized $\vec{n}p$ scattering have been performed in the energy region of the narrow resonance structure $d^*$ with $I(J^P) = 0(3^+)$, $M \approx$ 2380…
High-$p_T$ particle spectra in $p+p$ ($\bar p + p$), $p+A$ and $A+B$ collisions are calculated within a QCD parton model in which intrinsic transverse momentum, its broadening due to initial multiple parton scattering, and jet quenching due…
We present a discrete model of resonant scattering of waves by an open periodic waveguide. The model elucidates a phenomenon common in electromagnetics, in which the interaction of plane waves with embedded guided modes of the waveguide…
We report our recent effort for the extraction of resonance parameters (complex pole mass and residues etc.) associated with Lambda* and Sigma* hyperons. This was accomplished via a comprehensive partial-wave analysis of the data for K^- p…
Working with a pion mass $m_\pi \approx 150$ MeV, we study $\pi\pi$ and $K\pi$ scattering using two flavours of non-perturbatively improved Wilson fermions at a lattice spacing $a\approx 0.071$ fm. Employing two lattice volumes with linear…
I discuss recent results on the electroproduction and photoproduction of mesons in the region of non-strange baryon resonances. Results on the quadrupole transition from the ground state nucleon to the Delta(1232) show the importance of…
We extract the P-wave pi-pi phase shift for five values of pion relative momenta, which gives information on the rho resonance. The Breit-Wigner formula describes the pi-pi phase shift dependence nicely and we extract m(rho)=792(7)(8) MeV…
Calculations of the elastic $I=\frac{3}{2}$ nucleon-pion scattering phase shifts on two lattice QCD ensembles with $m_\pi=200\mathrm{MeV}$ and $280\mathrm{MeV}$ are presented. The ensembles both employ $N_\mathrm{f} = 2+1$ Wilson clover…
From a three-dimensional boundary value problem for the time harmonic classical Maxwell equations, we derive the dispersion relation for a surface wave, the edge plasmon-polariton (EP), that is localized near and propagates along the…
Charge exchange process $\pi^-p\to\pi^0n$ and elastic scatterings $\pi^\pm p\to \pi^\pm p$ are investigated within the Regge framework where the relativistic Born amplitude is reggeized for the $t$-channel meson exchange. Charge exchange…
We present the first lattice QCD study of coupled-channel $D\pi$, $D\eta$ and $D_{s}\bar{K}$ scattering in isospin-1/2 in three partial waves. Using distillation, we compute matrices of correlation functions with bases of operators capable…
Resonance parameters (pole masses and residues) associated with the excited states of hyperons, Lambda^* and Sigma^*, are extracted within a dynamical coupled-channels model developed recently by us [Phys. Rev. C 90, 065204 (2014)] through…
Assuming that the $\pi^+\pi^-$ photoproduction at forward angles and high energies is dominated by one pion exchange we calculate the $\pi^+\pi^-$ mass distributions for low partial waves. Predictions of the model agree well Assuming that…