The Spectrum of Kaon States in the Isodoublet strangeness S = 1 T_1u Channel by the Stochastic LapH Method in Lattice QCD

<p>Lattice QCD calculations of energies in bosonic channels have mostly been restricted<br>to the use of quark-antiquark meson operators due to the computational<br>challenges associated with evaluating correlation functions of multi-meson operators.<br>The stochastic LapH method has provided an efficient way to compute correlation<br>functions involving multi-hadron operators. This method is applied to construct a<br>58x58 correlation matrix using 9 single-meson operators and 49 two-meson operators<br>in the isodoublet strangeness S = 1 T_1u channel, which contains the spin-1 and spin-3<br>kaon states. The matrix of temporal correlations is evaluated using a Monte Carlo<br>ensemble of 551 configurations on an anisotropic 24³ x 128 lattice. Due to computational<br>limitations, light quark masses are used that produce an unphysically heavy<br>pion having a mass around 390 MeV, but the strange quark mass is tuned to its physical<br>value. A clover-improved Wilson fermion action is used in generating the Monte<br>Carlo ensemble, and the correlators are formed using source and sink operators constructed<br>out of Laplacian Heaviside smeared quark fields displaced with stout-smeared<br>gauge links. Overlap factors are used to identify the finite-volume eigenstates that<br>should evolve into the kaon resonances in infinite volume. These results are compared<br>to experiment and to results from a previous study for the isovector nonstrange T⁺_1u channel.</p>