Low-energy $DD$ scattering in lattice QCD

Abstract

We present the first lattice QCD calculation of single-channel $DD$ scattering with quantum numbers $I(J^P)=1(0^{+})$ and $0(1^{-})$. The calculation is performed on the $2+1$ flavor Wilson-Clover ensembles with a lattice spacing $a\simeq 0.077$ fm and two different pion masses, $m_{\pi }\simeq 207$ and $305$ MeV. The scattering parameters are determined using the Lüscher's finite volume method. Our results indicate a weak repulsive interaction in the $1(0^{+})$ channel and a slightly attractive interaction in the $0(1^{-})$ channel. The $S$-wave isovector $DD$ scattering length and effective range, extrapolated to the physical pion mass, are $(-0.25\pm 0.08\pm 0.12)$ fm and $(-5.7\pm 4.5\pm 1.7)$ fm, respectively.

Comments: 23 pages, 8 figures. Version to appear in Phys. Rev. D