%0 Journal Article
%A Rendon, Gumaro
%A Leskovec, Luka
%A Meinel, Stefan
%A Negele, John
%A Paul, Srijit
%A Petschlies, Marcus
%A Pochinsky, Andrew
%A Silvi, Giorgio
%A Syritsyn, Sergey
%T I = 1 / 2 S -wave and P -wave Kπ scattering and the κ and K* resonances from lattice QCD
%J Physical review / D
%V 102
%N 11
%@ 2470-0010
%C Melville, NY
%I Inst.812068
%M FZJ-2021-00462
%P 114520
%D 2020
%X We present a lattice-QCD determination of the elastic isospin-$1/2$ $S$-wave and $P$-wave $K{\pi}$ scattering amplitudes as a function of the center-of-mass energy using L\"uscher's method. We perform global fits of $K$-matrix parametrizations to the finite-volume energy spectra for all irreducible representations with total momenta up to $\sqrt{3}\frac{2{\pi}}{L}$; this includes irreducible representations (irreps) that mix the $S$- and $P$-waves. Several different parametrizations for the energy dependence of the $K$-matrix are considered. We also determine the positions of the nearest poles in the scattering amplitudes, which correspond to the broad ${\kappa}$ resonance in the $S$-wave and the narrow ${K}^{*}(892)$ resonance in the $P$-wave. Our calculations are performed with $2+1$ dynamical clover fermions for two different pion masses of 317.2(2.2) and 175.9(1.8) MeV. Our preferred $S$-wave parametrization is based on a conformal map and includes an Adler zero; for the $P$-wave, we use a standard pole parametrization including Blatt-Weisskopf barrier factors. The $S$-wave ${\kappa}$-resonance pole positions are found to be $[0.86(12){-}0.309(50)i]\text{ }\text{ }\mathrm{GeV}$ at the heavier pion mass and $[0.499(55){-}0.379(66)i]\text{ }\text{ }\mathrm{GeV}$ at the lighter pion mass. The $P$-wave ${K}^{*}$-resonance pole positions are found to be $[0.8951(64){-}0.00250(21)i]\text{ }\text{ }\mathrm{GeV}$ at the heavier pion mass and $[0.8718(82){-}0.0130(11)i]\text{ }\text{ }\mathrm{GeV}$ at the lighter pion mass, which corresponds to couplings of ${g}_{{K}^{*}K{\pi}}=5.02(26)$ and ${g}_{{K}^{*}K{\pi}}=4.99(22)$, respectively.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000602847800003
%R 10.1103/PhysRevD.102.114520
%U https://juser.fz-juelich.de/record/889854