Performance evaluation of IB-DFE-based strategies for SC-FDMA systems

The aim of this paper is to propose and evaluate multi-user iterative block decision feedback equalization (IB-DFE) schemes for the uplink of single-carrier frequency-division multiple access (SC-FDMA)-based systems. It is assumed that a set of single antenna users share the same physical channel to transmit its own information to the base station, which is equipped with an antenna array. Two space-frequency multi-user IB-DFE-based processing are considered: iterative successive interference cancellation and parallel interference cancellation. In the first approach, the equalizer vectors are computed by minimizing the mean square error (MSE) of each individual user, at each subcarrier. In the second one, the equalizer matrices are obtained by minimizing the overall MSE of all users at each subcarrier. For both cases, we propose a simple yet accurate analytical approach for obtaining the performance of the discussed receivers. The proposed schemes allow an efficient user separation, with a performance close to the one given by the matched filter bound for severely time-dispersive channels, with only a few iterations

Revisiting the charged kaon mass

The precision of the charged kaon mass is an order of magnitude worse than the precision of the charged pion mass mainly due to two inconsistent measurements. We plan to improve this precision by determining the charged kaon mass with the requested accuracy in the measurements of X-ray transitions in kaonic atoms of selected solid targets with the HPGe detector at DAΦNE in Laboratori Nazionali di Frascati, Italy. The measurements will be performed in parallel with SIDDHARTA-2 measurements of X-ray transitions in gaseous targets. The status of the preparation of the measurements will be presented

Status and perspectives for low energy kaon-nucleon interaction studies at DAΦNE : from SIDDHARTA to SIDDHARTA-2

The study of the antikaon nucleon system at very low energies plays a key role for the understanding of the strong interaction between hadrons in the strangeness sector. The information provided by the low energy kaon- nucleon interaction is accessible through the study of kaonic atoms. The lightest atomic systems, namely the kaonic hydrogen and the kaonic deuterium, provide the isospin dependent kaon-nucleon scattering lengths by measuring the X-rays emitted during their de-excitation to the 1s level. Until now, the most precise kaonic hydrogen measurement and an exploratory measurement of kaonic deuterium were carried out at the DAΦNE collider by the SIDDHARTA collaboration, combining the excellent quality kaon beam delivered by the collider with new experimental techniques, as fast and very precise X-ray detectors, like the Silicon Drift Detectors. Today, the most important experimental information missing in the field of the low-energy antikaon-nucleon interactions is the experimental determination of the hadronic energy shift and width of kaonic deuterium, and will be measured by the new SIDDHARTA-2 experiment, which is installed in DAΦNE and is ready to start the data taking campaign

Towards the first kaonic deuterium measurement with the SIDDHARTA-2 experiment at DAΦNE

The SIDDHARTA-2 experiment is going to perform the longawaited high precision X-ray measurement of kaonic deuterium, obtaining for the first time the values of the shift and the width induced by the strong interaction on the fundamental level. By combining this unprecedented result with the analogous kaonic hydrogen measurement performed by the SIDDHARTA experiment, it will be possible to extract the isospin-dependent antikaon-nucleon scattering lengths, providing direct information on the Quantum Chromodynamics (QCD) in the non-perturbative Chromodynamics (QCD) in the non-perturbative regime in the strangeness sector. This paper describes the SIDDHARTA-2 experiment, presently installed at the DAΦNE collider of Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali di Frascati, and the results obtained during the kaonic helium run, preparatory for the kaonic deuterium data taking campaign planned for 2022

Characterization of the SIDDHARTA-2 luminosity monitor

A luminosity monitor, based on plastic scintillator detectors, has been developed for the SIDDHARTA-2 experiment aiming to perform high precision measurements of kaonic atoms and was installed in 2020 on the DAFNE $e^+e^-$ collider at LNF (Laboratori Nazionali di Frascati, INFN). The main goal of this system is to provide the~instantaneous and integrated luminosity of the DAFNE facility by measuring the rate of $K^+K^-$ correlated pairs emitted by the phi meson decay. This task requires an accurate timing of the DAQ signals, as well as timing resolution below 1ns, in order to disentangle the $K^\pm$ signals from the background minimum ionizing particles (MIPs) produced during the $e^+e^-$ collisions at DAFNE. In this paper the luminosity monitor concept as well as its laboratory characterization and the first results inside DAFNE are presented.Comment: Published in JINS

Main features of the SIDDHARTA-2 apparatus for kaonic deuterium X-ray measurements

The low-energy, non-perturbative regime of QCD can be studied directly by X-ray spectroscopy of light kaonic atoms. The SIDDHARTA-2 experiment, located at the DAΦNE collider, aims to measure the 2p $\to$ 1s transition in kaonic deuterium for the first time to extract the antikaon-nucleon scattering lengths. This measurement is impeded, inter alia, by the low K$^{-}$d X-ray yield. Hence, several updates have been implemented on the apparatus to increase the signal-to-background ratio, which are discussed in detail in this paper: a lightweight gas target cell, novel Silicon Drift Detectors for the X-ray detection with excellent performance, and a veto system for active background suppression. The experiment has undergone a first preparatory run during DAΦNE’s commissioning phase in 2021, concluding with a successful kaonic helium measurement

BibGlimpse: The case for a light-weight reprint manager in distributed literature research

Background While text-mining and distributed annotation systems both aim at capturing knowledge and presenting it in a standardized form, there have been few attempts to investigate potential synergies between these two fields. For instance, distributed annotation would be very well suited for providing topic focussed, expert knowledge enriched text corpora. A key limitation for this approach is the availability of literature annotation systems that can be routinely used by groups of collaborating researchers on a day to day basis, not distracting from the main focus of their work. Results For this purpose, we have designed BibGlimpse. Features like drop-to-file, SVM based automated retrieval of PubMed bibliography for PDF reprints, and annotation support make BibGlimpse an efficient, light-weight reprint manager that facilitates distributed literature research for work groups. Building on an established open search engine, full-text search and structured queries are supported, while at the same time making shared collections of annotated reprints accessible to literature classification and text-mining tools. Conclusion BibGlimpse offers scientists a tool that enhances their own literature management. Moreover, it may be used to create content enriched, annotated text corpora for research in text-mining

Studies of the linearity and stability of silicon drift detectors for kaonic atoms X-ray spectroscopy

The SIDDHARTA-2 experiment at the DAFNE collider aims to perform precision measurements of kaonic atoms X-ray spectroscopy for the investigation of the antikaon?nucleon strong interaction. To achieve this goal, novel large-area Silicon Drift Detectors (SDDs) have been developed. These devices have special geometry, field configuration, and readout electronics that ensure excellent performance in terms of linearity and stability. The paper presents preliminary results for the linearity determination and stability monitoring of the SDDs system during the measurement of kaonic deuterium carried out in the summer of 2022

The SIDDHARTA-2 experiment : preparation for the first kaonic deuterium measurement

The SIDDHARTA-2 experiment aims to perform the first measurement of the kaonic deuterium 2p → 1s x-ray transitions. The apparatus is presently installed at the interaction region of the DAΦNE electron-positron collider at the National Laboratories of Frascati (LNF-INFN), in Italy. Kaonic deuterium and kaonic hydrogen 2p → 1s x-ray transitions measurements, the latter one already performed by the SIDDHARTA collaboration, allow the determination of antikaon-nucleon scattering lengths. A description of the SIDDHARTA-2 apparatus in preparation for the kaonic deuterium measurement is provided in this paper