Preliminary study of kaonic deuterium X-rays by the SIDDHARTA experiment at DAFNE

TL;DR

This paper reports on an exploratory measurement of kaonic deuterium X-rays using the SIDDHARTA experiment at DAFNE, aiming to understand low-energy antikaon-nucleon interactions through atomic spectroscopy.

Contribution

It presents the first limits on kaonic deuterium X-ray yields and introduces the upcoming SIDDHARTA-2 experiment for further investigation.

Findings

Set an upper limit for K-series transition yield in deuterium

Provided initial data for kaonic deuterium X-ray spectroscopy

Laid groundwork for future precise measurements of antikaon-nucleon interactions

Abstract

The study of the KbarN system at very low energies plays a key role for the understanding of the strong interaction between hadrons in the strangeness sector. At the DAFNE electron-positron collider of Laboratori Nazionali di Frascati we studied kaonic atoms with Z=1 and Z=2, taking advantage of the low-energy charged kaons from Phi-mesons decaying nearly at rest. The SIDDHARTA experiment used X-ray spectroscopy of the kaonic atoms to determine the transition yields and the strong interaction induced shift and width of the lowest experimentally accessible level (1s for H and D and 2p for He). Shift and width are connected to the real and imaginary part of the scattering length. To disentangle the isospin dependent scattering lengths of the antikaon-nucleon interaction, measurements of Kp and of Kd are needed. We report here on an exploratory deuterium measurement, from which a limit for the yield of the K-series transitions was derived: Y(K_tot)<0.0143 and Y(K_alpha)<0.0039 (CL 90%). Also, the upcoming SIDDHARTA-2 kaonic deuterium experiment is introduced.