Silicon Drift Detectors’ Spectroscopic Response during the SIDDHARTA-2 Kaonic Helium Run at the DAΦNE Collider

A large-area silicon drift detectors (SDDs) system has been developed by the SIDDHARTA-2 collaboration for high precision light kaonic atom X-ray spectroscopy at the DAΦNE collider of Istituto Nazionale di Fisica Nucleare—Laboratori Nazionali di Frascati. The SDDs’ geometry and electric field configuration, combined with their read-out electronics, make these devices suitable for performing high precision light kaonic atom spectroscopy measurements in the background of the DAΦNE collider. This work presents the spectroscopic response of the SDDs system during the first exotic atoms run of SIDDHARTA-2 with kaonic helium, a preliminary to the kaonic deuterium data taking campaign. The SIDDHARTA-2 spectroscopic system has good energy resolution and a 2 μs timing window which rejects the asynchronous events, scaling the background by a factor of 10−5. The results obtained for the first exotic atoms run of SIDDHARTA-2 prove this system to be ready to perform the challenging kaonic deuterium measurement.

X-ray Detectors for Kaonic Atoms Research at DAΦNE

This article presents the kaonic atom studies performed at the INFN National Laboratory of Frascati (Laboratori Nazionali di Frascati dell’INFN, LNF-INFN) since the opening of this field of research at the DA Φ NE collider in early 2000. Significant achievements have been obtained by the DA Φ NE Exotic Atom Research (DEAR) and Silicon Drift Detector for Hadronic Atom Research by Timing Applications (SIDDHARTA) experiments on kaonic hydrogen, which have required the development of novel X-ray detectors. The 2019 installation of the new SIDDHARTA-2 experiment to measure kaonic deuterium for the first time has been made possible by further technological advances in X-ray detection.

Energy Response of Silicon Drift Detectors for Kaonic Atom Precision Measurements

Novel, large-area silicon drift detectors (SDDs) have been developed to perform precision measurements of kaonic atom X-ray spectroscopy, for the study the K ¯ N strong interaction in the low-energy regime. These devices have special geometries, field configurations and read-out electronics, resulting in excellent performances in terms of linearity, stability and energy resolution. In this work the SDDs energy response in the energy region between 4000 eV and 12,000 eV is reported, revealing a stable linear response within 1 eV and good energy resolution.

Single-and multi-nucleon K− interactions with nuclei near threshold

Six recent SU(3) chiral-model EFT approaches to the K̅-nucleon interaction near threshold, constrained by K− p low-energy scattering and reaction data and by the kaonic hydrogen SIDDHARTA experiment, are used as input in kaonic atom calculations. Good agreement with the world-data on kaonic atoms is achieved with optical potentials built on the above models only when K̅N amplitudes are supplemented by a phenomenological multi-nucleon term. Comparing predictions with experimental single-nucleon absorption-at-rest fractions on nuclei, only two of the models together with their associated phenomenological term are acceptable. The information content of K−-nucleus data near threshold is discussed and the topic of deeply-bound kaonic atoms is re-visited.