### Research

**THE ***ρ* **MESON SPECTRUM AND ***K **π* **SCATTERING WITH PARTIAL WAVE MIXING IN LATTICE QCD**

The finite-volume QCD spectrum in the *I* = 1, *S *= 0, parity-odd, *G*-parity-even channels for zero total momentum is studied using lattice QCD, and the *K*-matrix for *K **π* scattering is investigated to determine the mass and decay width of the *K** (892) from first principles. The recently developed stochastic LapH method has proven to be a valuable tool in lattice QCD calculations when all-to-all quark propagators are needed, as is the case for isoscalar mesons and two-hadron operators. This method is especially important for large volumes where other methods do not scale well. These calculations were done with 412 gauge configurations using clover-improved Wilson fermions on a large anisotropic 32^{3} ⨯ 256 lattice with a pion mass near 240 MeV. The stationary states determined to be single-particle dominated are compared with the experimental resonances and are found to be in reasonable agreement. Additionally, the initial development of tetraquark operators is described.

Co-advisor: Dr. Colin Morningstar, CMU

http://d-scholarship.pitt.edu/33243/