On the width of the $K^{-}$D atom ground state

Abstract

Experiments at DA$\Phi$NE-Frascati and at J-PARC are scheduled to produce $K^{-}$D atoms and observe their X-ray cascade down to the 1$S$ ground state (g.s.), thereby measuring its strong-interaction width and shift away from a purely Coulomb state. A width ${\Gamma }_{1S}\lesssim 1$ keV will ensure good resolution of the X-ray transitions feeding the 1$S$ g.s. Here we study the expected $K^{-}$D 1$S$ g.s. width from the perspective of global fits to level shifts and widths in heavier kaonic atoms across the periodic table, using $K^{-}$ nuclear optical potentials constructed from $\bar{K}N$ chiral interaction models. Special attention is paid to the subthreshold energy at which the $\bar{K}N$ subsystem interacts in the $K^{-}$D atomic g.s. Within this approach we predict strong-interaction upward level shift of close to 700 eV and width of about 1.2 to 1.3 keV for the $K^{-}$D atom 1$S$ g.s., in fair agreement with genuinely three-body $K^{-}$D atom calculations. Comparison is made with ${\pi }^{-}$D atom phenomenology.

14 pages, 2 figures, 2 tables; v1--to be submitted for publication, comments are welcome; v2--slightly edited, submitted for publication; v3--very slightly revised without any of the original results changed, accepted for publication in NPA

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• Extended Partial-Wave Analysis of piN Scattering Data
• In-medium nuclear interactions of low-energy hadrons
• $K^{-}N$ amplitudes below threshold constrained by multinucleon absorption
• The role of nucleon recoil in low-energy antikaon-deuteron scattering
• Onset of $\eta$-meson binding in the He isotopes
• Precision determination of the dpi -> NN transition strength at threshold
• Recoil corrections in antikaon-deuteron scattering
• Three-body calculation of the $1s$ level shift in kaonic deuterium with realistic $\bar{K}N$ potentials
• Testing in-medium $\pi N$ dynamics on pionic atoms
• Three-body calculation of the $1s$ level shift in kaonic deuterium

Cited by in corpus (1)

• Kaon-deuteron femtoscopy from unitarized chiral interactions