Kaon–nucleon scattering lengths from kaonic deuterium experiments

Abstract

The extraction of the S-wave kaon-nucleon scattering lengths a0 and a1 from a combined analysis of existing kaonic hydrogen and synthetic deuterium data has been carried out within the framework of a low-energy effective field theory. It turns out that with the present DEAR central values for the kaonic hydrogen ground-state energy and width, a solution for a0 and a1 exists only in a restricted domain of input values for the kaon-deuteron scattering length. Consequently, measuring this scattering length imposes stringent constraints on the theoretical description of the kaon-deuteron interactions at low energies.

Kaonic deuterium and low-energy antikaon-nucleon interaction

“…The improved Deser formula [4,14], derived from non-relativistic effective field theory (EFT), is frequently used in the investigation of strong-interaction effects in hadronic atoms. This relation connects the 1s level shift ∆E and width Γ of a kaonic atom with the K − -nucleus scattering length, a, as follows: (9) 910 989 Resummed formula (10) 818 1188…”

“…This requires as input the K − d scattering length, a K − d . In the fixed center approximation (FCA) for the nucleons, a K − d derived from a multiple scattering series is given as [4,23] …”

Probing Strong Interaction with Kaonic Atoms — from DAΦNE to J-PARC

“…"The necessity to perform measurements of the kaonic deuterium ground state observables is justified by the fact that, unlike the case of pionic atoms, the measurement of only the kaonic hydrogen spectrum does not allow -even in principle -to extract independently both s-wave antikaon-nucleon scattering lengths a 0 and a 1 ", quoting from U.-G. Meisser [8]. The kaonic deuterium X-ray measurement represents the most important experimental information missing in the field of the low-energy antikaon-nucleon interactions today.…”

K−3He andK−4He interactions at low energies

“…Futhermore, in Ref. [36] it was proposed the idea of extraction of the S -wave kaon-nucleon scattering lengths a 0 and a 1 from a combined analysis of existing kaonic hydrogen and synthetic deuterium data. In the framework of the low-energy effective field theory the restrictions on the values of the scattering lengths a I , I=0 [37,38].…”