Year: 2010
Type: article
Abstract: We have computed the $SU(2)$ low-energy constant ${l}_{5}$ and the mass splitting between charged and neutral pions from a lattice QCD simulation of ${n}_{f}=2+1$ flavors of domain wall fermions at a scale of ${a}^{\ensuremath{-}1}=2.33\text{ }\text{ }\mathrm{GeV}$. Relating ${l}_{5}$ to the $S$ parameter in QCD we obtain a value of $S({m}_{H}=120\text{ }\text{ }\mathrm{GeV})=0.42(7)$, in agreement with previous determinations. Our result can be compared with the value of $S$ from electroweak precision data which constrains strongly interacting models of new physics like technicolor. This work in QCD serves as a test for the methods to compute the $S$ parameter with domain wall fermions in theories beyond the standard model. We also infer a value for the pion mass splitting in agreement with experiment.
Institution: University of Edinburgh
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: G8353447643, G8516912585
OpenAlex ID: W2145664071