Studies of kaonic atoms at the DAΦNE collider: from SIDDHARTA to SIDDHARTA-2

D Sirghi ,L Fabbietti ,K Piscicchia ,A Clozza ,Marco Carminati,A Spallone ,J Márton ,M Skurzok ,M Bragadireanu ,M Miliucci ,S Okada ,R Del Grande ,P Levi Sandri ,C Guaraldo ,A Scordo ,P Moskal ,A Baniahmad ,C Fiorini ,C Curceanu ,A Amirkhani ,L De Paolis ,M Iwasaki ,M Tüchler ,D Bosnar ,F Sirghi ,E Widmann ,M Cargnelli ,O Vázquez Doce ,D Pietreanu ,M Silarski ,Szymon Niedźwiecki ,M Bazzi ,M Iliescu ,J Zmeskal

doi:10.1088/1742-6596/1526/1/012023

Abstract

The DAΦNE electron-positron collider of the Laboratori Nazionali di Frascati of INFN is a worldwide unique low-energy kaon source and for this reason is suitable for low-energy kaon physics like kaonic atoms and kaon-nucleons/nuclei interaction studies. Kaonic atoms are atomic systems where an electron is replaced by a negatively charged kaon, containing the strange quark, which interacts in the lowest orbits with the nucleus also by the strong interaction. As a result, their study offers the unique opportunity to perform experiments equivalent to scattering at vanishing relative energy. This allows to study the strong interaction between the antikaon and the nucleon or the nucleus “at threshold”, without the need of ad hoc extrapolation to zero energy, as in scattering experiments. The most precise kaonic hydrogen measurement to date, together with an exploratory measurement of kaonic deuterium, were carried out by the SIDDHARTA collaboration at the DAΦNE electron-positron collider of LNF-INFN, by combining the excellent quality kaon beam delivered by the collider with new experimental techniques, as fast and precise Silicon-Drift X-ray Detectors. The measurement of kaonic deuterium will be realized in the near future by SIDDHARTA-2, a major upgrade of SIDDHARTA.

Highlights

T he SID DHARTA -2 experim ent The kaonic deuterium X-ray m easurement represents the most im portant experimental information missing in the low-energy antikaon-nucleon interactions sector, and for this reason a new experim ent, SIDDHARTA-2, is under way, m aking use of an improved apparatus
The expected precision of the experim ental m easurem ent at D A FN E is given as the rectangle coloured in red (shift e 1s= ± 30 eV, w idth r 1s = ± 75 eV)

Summary

Introduction

In 2009 SIDDHARTA perform ed th e m ost precise m easurem ent of kaonic hydrogen [1]. The 1s -level shift e 1s and w idth r 1s of kaonic hydrogen were determ ined to be: e 1s = -2 8 3 ± 36(stat) ± 6(syst) e V

Results

Conclusion