Distributed data processing and computing is highly relevant to the BM@N experiment, the first ongoing experiment of the NICA project due to the high data flow, the sequential processing of which would take hundreds of years. The latest BM@N Run alone produced about half a petabyte of raw data, and when the experiment reaches its design parameters, the amount of the data will increase approximately by an order of magnitude. To solve this problem and combine all distributed resources of the experiment into a single computing and storage system as well as provide the automation of job processing flows, the computing software architecture has been developed and is being implemented. It includes a complex of software systems for distributed processing of BM@N data flows and is described in the paper.

A huge amount of experimental data should be collected, stored and processed in large modern high-energy physics experiments, including the experiments of the NICA (Nuclotron-based Ion Collider fAcility) project at the Joint Institute for Nuclear Research. In this regard, corresponding performance requirements are put forward for existing online systems. The online data processing system developed for the BM@N experiment within the NICA project is based on a distributed architecture, enabling it to meet high performance requirements through scalability and parallel computing. The purpose of the online system is selective data processing (conversion to event digits in the CERN ROOT format and fast event reconstruction) and data monitoring of the ongoing experiment. To achieve this goal, the FairMQ package implemented by the FAIR collaboration (GSI Institute, Germany) has been chosen to communicate distributed processes executed on the nodes of the computing infrastructure with each other through the exchange of their messages. One of the issues in developing and using such systems is the problem of the distributed run and control of the processes. The task has been solved by using the FAIR DDS (Dynamic Deployment System) toolkit. The BM@N online system starts the predefined software tasks in a required sequence and allows managing them during sessions, including the transmission of messages between the tasks and the update of some properties. The paper presents the purposes and architecture of the Online Data Processing System for the BM@N experiment and features of the current implementation.

BM@N (Baryonic Matter at Nuclotron) is the first experiment operating and taking data at the Nuclotron/NICA ion-accelerating complex.The aim of the BM@N experiment is to study interactions of relativistic heavy-ion beams with fixed targets. We present a technical description of the BM@N spectrometer including all its subsystems.

The Event Metadata System (EMS) developed for BM@N, a fixed target experiment of the NICA (Nuclotron-based Ion Collider fAcility) project has been designed to store and index event records for particle collisions obtained at the BM@N facility and subsequently reconstructed. The system enables to quickly search for a required set of physics events based on various given criteria for further physics analyses. The main implemented interfaces to the EMS include Web UI (user interface) and REST API (application programming interface), that are presented in the paper in detail. The both interfaces have its own main use patterns, namely, the Web UI is mostly employed for browsing the Event Catalogue and checking its overall state, while the REST API helps to integrate the EMS with other software systems of the experiment, such as the main BM@N framework, BmnRoot to conveniently select events for a particular physics analysis. The interfaces have been developed using Kotlin multiplatform technology, hence, both front-end and back-end components of the Web service are parts of one project using the same programming language and a common codebase.

NICA (Nuclotron-based Ion Collider facility) is a new accelerator complex, which is under construction at the Joint Institute for Nuclear Research in Dubna to study properties of dense baryonic matter. The experiments of the NICA projects have already generated and obtained substantial volumes of event data, and it is expected that the overall number of stored events will increase from the current value of hundreds of millions to several billion events per year. The developed Event Metadata System is required to store and index experimental event records obtained at NICA facilities, allowing to quickly search for only necessary events based on various criteria for further processing and physics analyses. The main aim of the information system that is described is to speed up desired physics analyses and data quality checks. In addition, it allows reducing the load of the NICA computing infrastructure. The Event Metadata System, which is presented in the paper, is integrated with other experimental and software systems, in particular, NICA ROOT-based frameworks and implemented Condition Database. An access and management of the event metadata in the Event Catalogue being used to select only events for a particular physics analysis are provided via several interfaces, such as REST API, Web UI, and a dedicated C++/ROOT interface. The detailed architecture of the system and developed services including monitoring are also presented.

The efficient operation of large physics experiments is ensured by many factors, one of which is software used for both online and offline systems. At present, a set of information systems is being developed for the NICA experiments, including the first fixed target experiment, BM@N. These information systems are used, among other things, for centralized storage, access and exchange of information being necessary for the experiment. Currently, the software complex of the BM@N experiment contains the following set of the information systems, such as the Online Electronic Logbook (e-Log platform), Configuration Information System, Unified Condition Database (UniConDa), Geometry Database and Event Metadata System (EMS). It is obvious that the systems will be in demand in other experiments of the NICA project, therefore special attention is paid to development of a new common deployment complex that provides convenient, configurable installation of the listed information systems for other particle collision experiments, but primarily for the experiments at NICA. The paper describes the architecture, used methods and approaches to the implementation of the common deployment system, as well as the status of its realization.

The collection, storage and processing of experimental data are an integral part of modern high-energy physics experiments. The Configuration Information System (CIS) based on the Configuration Database (ConfigDb) is an essential element of a complex of information systems developed for the NICA experiments. The CIS is used to store and provide data on the configuration of the experiment hardware and software systems when collecting data from the detectors in online mode. The ConfigDb stores both a set of various configuration parameters and descriptions of a sequence of online software tasks to be started and run during experiment sessions. The system allows loading configuration information, activating hardware setups and launching all necessary software applications with the required parameters on the specified distributed nodes. The CIS architecture mainly contains the ConfigDb and Configuration Manager, which uses the Dynamic Deployment System API for managing tasks and providing intercommunication. The manager loads configuration data from the database, starts software tasks in a described sequence and supports task process management. The client-server architecture of the CIS is presented. The client has been implemented as a Web service to manage configuration parameters by users.

First physics results of the BM@N experiment at the Nuclotron/NICA complex are presented on π+ and K+ meson production in interactions of an argon beam with fixed targets of C, Al, Cu, Sn and Pb at 3.2 A GeV. Transverse momentum distributions, rapidity spectra and multiplicities of π+ and K+ mesons are measured. The results are compared with predictions of theoretical models and with other measurements at lower energies.

The Configuration Database is an essential part of a complex of information systems that have been developed for the experiments of the NICA project at the Joint Institute for Nuclear Research. The developed database stores both a set of various configuration parameters, such as those required for setting the detectors into operation modes, for instance, working voltage, and descriptions of a sequence of software tasks to be started and run during experiment sessions. The corresponding Configuration Information System presented in the report is based on the implemented database and provides configuration information for data acquisition and other online processing systems, activating those hardware setups that are needed in the current experiment session. In addition, the system starts the described software tasks in the required sequence and allows managing them during sessions, including the transmission of messages between tasks and the update of some properties. The architecture of the Configuration Information System is presented as well, it has been implemented using the client-server model, where the server ensures interactions with the Configuration Database, and the client has been developed as a Web application to view and edit configuration parameters by users.

The NICA collider complex currently under construction at the Joint Institute for Nuclear Research in Dubna is aimed at creating and investigating hot baryonic matter under extreme conditions. During offline and even online data processing, a large set of various parameters of experiment systems and conditions, under which the experiments are conducted, are required for experimental event reconstruction, detector simulation, physics analysis and quality assurance. To solve the task of storing the required parameters and information on the NICA experiments, which are necessary for further processing of the obtained experimental data (as well as simulated events), an information system has been developed on the basis of the condition database. For convenient management of the data stored in the database called Unified Database, a web application has been implemented for viewing, searching, managing and visualizing information on the experiments of the NICA project, such as information on sessions and runs, detectors, parameters and parameter values, and, in addition, generated simulation files. Furthermore, the developed information system provides collaboration members with a set of auxiliary services, such as data inspection and monitoring services, which improve the functionality of the system and make it more convenient. The paper presents the information system and its components including the condition database, user interfaces and web application, and implemented related services.

Acquiring, storing, processing and analyzing experimental and simulated data are an integral part of all modern high-energy physics experiments. These tasks are of particular importance in the experiments of the NICA megaproject at the Joint Institute for Nuclear Research (JINR) due to the high interaction rate and particle multiplicity of ion collision events. Therefore the task of automating the considered processes for the NICA complex is a very urgent topic. This article describes the status of the development of new information systems as well as a set of convenient information services for collaboration members to automate storing and processing of data and information on the experiments. The Geometry Information System and Online Electronic Logbook, which are on the final stage of implementation, are presented. In addition, the design of the Condition Database and Event Metadata System, which are scheduled to be completed next year, are described in detail. The systems provide storing of information required for event processing and physics analysis and organize a transparent, unified access and data management throughout the life cycle of the scientific research in the NICA megaproject. One of the key aspects-the integration of the information systems with the experiment software systems-is also presented.

The processing and analysis of experimental and simulated data are an integral part of all modern high-energy physics experiments. These tasks are of particular importance in the experiments of the NICA project at the Joint Institute for Nuclear Research due to the high interaction rate and large particle multiplicity of ion collision events, therefore, the task of automating the considered processes for the NICA complex has particular relevance. The paper describes a new information system based on the Condition Database, as well as related services to automate storing, managing, searching and using various parameters and operation modes of the on-going and future NICA experiments for experimental and simulated data processing. The implemented system provides the necessary information for event processing and physics analysis tasks, and organises the transparent, unifiedaccess to and management of the required parameter data in scientific research. The scheme and purposes of the Condition Database, its attributes, key aspects of the development are described. In addition, a common deployment system of the developed database and related services for the NICA experiments is noted.