| Preprint | |
| Report number | CERN-TH-2024-087 ; arXiv:2406.19193 |
| Title | Physical-mass calculation of $\rho(770)$ and $K^*(892)$ resonance parameters via $\pi \pi$ and $K \pi$ scattering amplitudes from lattice QCD |
| Author(s) | Boyle, Peter (Brookhaven ; Edinburgh U.) ; Erben, Felix (Edinburgh U. ; CERN) ; Gülpers, Vera (Edinburgh U.) ; Hansen, Maxwell T. (Edinburgh U.) ; Joswig, Fabian (Edinburgh U.) ; Lachini, Nelson Pitanga (Edinburgh U. ; Cambridge U., DAMTP) ; Marshall, Michael (Edinburgh U.) ; Portelli, Antonin (Edinburgh U. ; CERN ; RIKEN AICS, Kobe) |
| Imprint | 2024-06-27 |
| Number of pages | 27 |
| Subject category | hep-ph ; Particle Physics - Phenomenology ; hep-lat ; Particle Physics - Lattice |
| Abstract | We present our study of the $\rho(770)$ and $K^*(892)$ resonances from lattice quantum chromodynamics (QCD) employing domain-wall fermions at physical quark masses. We determine the finite-volume energy spectrum in various momentum frames and obtain phase-shift parameterizations via the Lüscher formalism, and as a final step the complex resonance poles of the $\pi \pi$ and $K \pi$ elastic scattering amplitudes via an analytical continuation of the models. By sampling a large number of representative sets of underlying energy-level fits, we also assign a systematic uncertainty to our final results. This is a significant extension to data-driven analysis methods that have been used in lattice QCD to date, due to the two-step nature of the formalism. Our final pole positions, $M+i\Gamma/2$, with all statistical and systematic errors exposed, are $M_{K^{*}} = 893(2)(8)(54)(2) \mathrm{MeV}$ and $\Gamma_{K^{*}} = 51(2)(11)(3)(0) \mathrm{MeV}$ for the $K^*(892)$ resonance and $M_{\rho} = 796(5)(15)(48)(2) \mathrm{MeV}$ and $\Gamma_{\rho} = 192(10)(28)(12)(0) \mathrm{MeV}$ for the $\rho(770)$ resonance. The four differently grouped sources of uncertainties are, in the order of occurrence: statistical, data-driven systematic, an estimation of systematic effects beyond our computation (dominated by the fact that we employ a single lattice spacing), and the error from the scale-setting uncertainty on our ensemble. |
| Other source | Inspire |
| Copyright/License | preprint: (License: arXiv nonexclusive-distrib 1.0) |
Record created 2024-06-29, last modified 2024-09-21
