SIDDHARTA-2 veto system design and performance for kaonic atoms studies at DAΦNE

¹ INFN-LNF, Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali di Frascati, Frascati, 00044 Roma, Italy
² Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb, Croatia
³ Horia Hulubei National Institute of Physics and Nuclear Engineering IFIN-HH Ma˘gurele, Romania
⁴ Stefan-Meyer-Institut für Subatomare Physik, Vienna, 1030, Austria
⁵ Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Milano, 20133, Italy
⁶ INFN Sezione di Milano, 20133, Italy
⁷ Physik Department E62, Technische Universität München, Garching, 85748, Germany
⁸ RIKEN, Tokyo 351-0198, Japan
⁹ Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Krakow, 30-348, Poland
¹⁰ Center for Theranostics, Jagiellonian University, Krakow, Poland
¹¹ Research Center for Electron Photon Science (ELPH), Tohoku University, Sendai, 982-0826, Japan
¹² Centro Ricerche Enrico Fermi – Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, Roma, 00184, Italy
¹³ University of Vienna, Vienna Doctoral School in Physics, Vienna, 1090, Austria

^* e-mail: francesco.sgaramella@lnf.infn.it
^** current address: ASI, Agenzia Spaziale Italiana, Roma, Italy

Published online: 8 December 2023

Abstract

Light kaonic atoms spectroscopy provides a unique approach to study the low-energy strong interaction in the strangeness sector. Precise measurements of X-ray emission from light kaonic atoms provide valuable information on kaon-nucleus interaction at threshold without the need for extrapolation as required in scattering experiments. The SIDDHARTA-2 experiment at the DAΦNE collider of INFN-LNF is now poised to perform the challenging measurements of the K⁻- d 2p → 1s transition to extract the isospin-dependent antikaonnucleon scattering lengths. To achieve this goal, the background reduction is a crucial factor. This paper provides an overview of the SIDDHARTA-2 Veto-1 system, which uses scintillators outside the vacuum chamber to detect charged particles produced by K− absorption by the nucleus. The arrival time of these particles is correlated with the position where the kaonic atom has been created inside the setup, allowing for the rejection of kaons stopped outside the target cell, which is a critical component for reducing the background and improve the accuracy of the measurement.