News on spectra from the NA61/SHINE experiment

NA61/SHINE is a fixed target experiment at the CERN Super-Proton-Synchrotron. The main goals of the experiment are to discover the critical point of strongly interacting matter and study the properties of the onset of deconfinement. In order to reach these goals, a study of hadron production properties is performed in nucleus-nucleus, proton-proton and proton-nucleus interactions as a function of collision energy and size of the colliding nuclei. In this talk, recent results on particle production in p+p interactions, as well as Be+Be and Ar+Sc collisions in the SPS energy range are reviewed. Transverse momentum, transverse mass and rapidity spectra obtained with various analysis methods are presented. Surprises in studies of signatures of onset of deconfinement are discussed. The results are compared with available world data

Diagram of High Energy Nuclear Collisions

Many new particles, mostly hadrons, are produced in high energy collisions between atomic nuclei. The most popular models describing the hadron production process are based on the creation, evolution and decay of resonances, strings or quark-gluon plasma. The validity of these models is under vivid discussion, and it seems that a common framework for this discussion is missing. Here we introduce the diagram of high energy nuclear collisions, where domains of the dominance of different hadron-production processes in the space of laboratory-controlled parameters, the collision energy and nuclear-mass number of colliding nuclei, are indicated. We argue, the recent experimental results locate boundaries between the domains, allowing for the first time to sketch an example diagram. Finally, we discuss the immediate implications for experimental measurements and model development following the sketch.Comment: Summar

Search of critical effects in NA61/SHINE

NA61/SHINE is a multi-purpose experiment to study hadron-proton, hadron-nucleus and nucleus-nucleus collisions at the CERN Super Proton Synchrotron (SPS). The experiment performs unique measurements for the physics of strong interactions as well as important reference measurements for neutrino and cosmic-ray physics. The primary goals of the experiment are the study of the onset of deconfinement and the search for the critical point of the strongly interacting matter, to uncover the mechanism of thermalisation and to test the validity of statistical models. For this purpose, a two-dimensional scan was performed by varying the beam momentum (13$A$--158$A$~GeV/$c$) and the size of colliding systems (p+p, p+Pb, Be+Be, Ar+Sc, Xe+La, Pb+Pb). In this contribution, we present recent NA61/SHINE results on the search for critical effects in spectra and fluctuations. We see no clear indication for the onset of deconfinement for intermediate colliding systems. Nevertheless, results from p+p interactions on spectra and onset of deconfinement reveal anomalous behaviour in proximity to transition energy. In fluctuation analysis of collisions of medium size nuclei at the top SPS energy, no prominent signal of critical point was observed

Kaon production in mid-rapidity in Be+Be collisions at the CERN SPS

This thesis presents inclusive spectra of identified charged hadrons, namely K + , K − , π + , π − , proton and anti-proton, produced in inelastic 7 Be+ 9 Be collisions at four beam momenta: 30A, 40A, 75A and 150A GeV/c. The data acquisition was performed by the NA61/SHINE Collaboration with the NA61/SHINE fixed target experiment placed at CERN SPS. The hadron production in Be+Be collisions was measured and studied for the first time in SPS energy range. Charged-hadron identification was obtained with the so-called tof − dE/dx analysis method, based on measurements of hadron mass by Time of Flight detectors and energy loss by Time Projection Chambers. The results were corrected for effects related to the spectrometer acceptance, detection and reconstruction efficiency, the contribution of particles originating in weak decays and secondary interactions, as well as the analysis technique. The double-differential particle spectra were derived as a function of rapidity and transverse momentum. Particular attention was paid to the strangeness production in mid-rapidity by studying the charged K meson spectra. The K + and K − yields in mid-rapidity were calculated and the transverse momentum spectra were parametrised by the inverse slope parameter. These results were further used in the study of the onset of deconfinement and the phenomenon of the light-nuclei collisions at ultra-relativistic energies. The identification of charged-hadron spectra in Be+Be collisions belongs to the main NA61/SHINE programme of the onset of deconfinement of strongly interacting matter study in collisions of light and intermediate-size ions. The results on strangeness production in mid-rapidity, derived in the framework of this thesis, were compared with the results from p+p interactions and Pb+Pb collisions at the same beam momenta per nucleon, measured by the NA61/SHINE and NA49 experiments, respectively, and also world data in broader collision energy range. Furthermore, the results on charged-kaon spectra in mid-rapidity were compared with the calculation of three microscopic theoretical models of high-energy nuclear collisions and confronted with the prediction of the Statistical Model of the Early Stage

Highlights from the NA61/SHINE strong-interactions programme

NA61/SHINE is a multipurpose fixed-target facility at the CERN SPS. The main goals of the NA61/SHINE strong-interactions programme are to discover the critical point of strongly interacting matter as well as to study the properties of the onset of deconfinement. In order to reach these goals, a study of hadron production properties is performed in nucleus-nucleus, proton-proton and proton-nucleus interactions as a function of collision energy and size of the colliding nuclei. In this contribution, the NA61/SHINE results from a strong interaction measurement programme are presented. In particular, the latest results from different reactions p+p, Be+Be, Ar+Sc, and Pb+Pb on hadron spectra, as well as intermittency, higher-order moments of multiplicity fluctuations and spectator induced electromagnetic effects are discussed

Strangeness production and onset of deconfinement study in NA61/SHINE

This contribution summarises the recent results of the NA61/SHINE experiment on strangeness production in the system size dependence will be presented. Preliminary results on K+ and K− production in central Ar+Sc collisions will be discussed within the scope of the onset of deconfinement. Furthermore, final results on Ξ− and Ξ+ hyperon production, as well as preliminary spectra of Ξ0 (1530) and Ξ0-bar (1530) produced in p+p interactions at 158 GeV/c will be reported along with results on an experimental search for pentaquarks

Produkcja kaonów w obszarze średnich pośpieszności w zderzeniach Be+Be przy SPS CERN

This thesis presents inclusive spectra of identified charged hadrons, namely K+ , K− , π + , π − , proton and anti-proton, produced in inelastic 7Be+9Be collisions at four beam momenta: 30A, 40A, 75A and 150A GeV/c. The data acquisition was performed by the NA61/SHINE Collaboration with the NA61/SHINE fixed target experiment placed at CERN SPS. The hadron production in Be+Be collisions was measured and studied for the first time in SPS energy range. Charged-hadron identification was obtained with the so-called tof − dE/dx analysis method, based on measurements of hadron mass by Time of Flight detectors and energy loss by Time Projection Chambers. The results were corrected for effects related to the spectrometer acceptance, detection and reconstruction efficiency, contribution of particles originating in weak decays and secondary interactions, as well as the analysis technique. The double-differential particle spectra were derived as a function of rapidity and transverse momentum. Particular attention was paid to the strangeness production in mid-rapidity by studying the charged K meson spectra. The K+ and K− yields in mid-rapidity were calculated and the transverse momentum spectra were parametrised by the inverse slope parameter. This results were further used in the study of the onset of deconfinement and the phenomenon of the light-nuclei collisions at ultra-relativistic energies. The identification of charged-hadron spectra in Be+Be collisions belongs to the main NA61/SHINE programme of the onset of deconfinement of strongly interacting matter study in collisions of light and intermediate-size ions. The results on strangeness production in mid-rapidity, derived in the framework of this thesis, were compared with the results from p+p interactions and Pb+Pb collisions at the same beam momenta per nucleon, measured by the NA61/SHINE and NA49 experiments, respectively, and also world data in broader collision energy range. Furthermore, the results on charged-kaon spectra in mid-rapidity were compared with the calculation of three microscopic theoretical models of high-energy nuclear collisions and confronted with prediction of the Statistical Model of the Early Stage.Niniejsza rozprawa przedstawia inkluzywne widma naładowanych hadronów, K+ , K− , π + , π − , protonów oraz antyprotonów, wyprodukowanych w nieelastycznych zderzeniach beryl-beryl, zmierzone po raz pierwszy dla czterech pędów wiązki: 30A, 40A, 75A i 150A GeV/c. Dane doświadczalne zostały zmierzone w ramach projektu NA61/SHINE, z wykorzystaniem układu detekcyjnego NA61/SHINE znajdującego się przy akceleratorze SPS w laboratorium CERN. Identyfikacja hadronów naładowanych została przeprowadzona metodą tof − dE/dx, opartą o pomiary masy hadronów w detektorach czasu przelotu (ToF) oraz średnich strat energii na jednostkę drogi w komorach projekcji czasowej (TPC). Wyniki analizy poprawiono, uwzględniając efekty związane z akceptacją detektora, wydajnością detekcji i rekonstrukcji cząstek, przyczynkiem cząstek pochodzących z rozpadów słabych i oddziaływań wtórnych, a także techniką analizy danych. Dwuwymiarowe widma krotności cząstek naładowanych wyznaczono w funkcji pośpieszności oraz pędu poprzecznego. Szczególną uwagę poświęcono produkcji dziwności w obszarze średnich pośpieszności poprzez analizę widm naładowanych kaonów w tym obszarze. Wyznaczono parametry tych widm: parametry nachylenia rozkładów pędu poprzecznego oraz krotności kaonów naładowanych w danym przedziale pośpieszności. Parametryzacja widm posłużyła dalszym badaniom dotyczącym progu na produkcję plazmy kwarkowo-gluonowej (QGP) oraz zderzeń lekkich jonów przy energiach ultra-relatywistycznych. Badania zawarte w tej pracy należą do głównego programu NA61/SHINE: poszukiwań progu na produkcję QGP w zderzeniach lekkich i średnich jąder. Widma kaonów i ich parametryzacja zostały zestawione z dostępnymi wynikami z oddziaływań proton-proton i ołów-ołów przy tych samych pędach wiązki na nukleon, zmierzonymi odpowiednio w eksperymentach NA61/SHINE i NA49. Dodatkowo wyniki ujęte w niniejszej pracy zostały porównane z modelami teoretycznymi opisującymi zderzenia jądrowe przy wysokich energiach

The Forward TPC system of the NA61/SHINE experiment at CERN: a tandem TPC concept

This paper presents the Forward Time Projection Chamber (FTPC) system of the NA61/SHINE experiment at the CERN SPS accelerator. This TPC system applies a novel tandem-TPC design to reduce the background originating from particle tracks not synchronous with the event trigger. The FTPC system is composed of three chambers with alternating drift field directions. The chambers were installed directly along the beamline region of the NA61/SHINE detector in a medium- to high-intensity (10-100 kHz) hadron or ion beam. The tandem TPC system has proved to be capable of rejecting out-of-time background tracks not associated with a primary interaction. In addition, the system performs tracking and inclusive dE/dx particle identification for particles at and near the beam momentum. This shows that a tandem-TPC-based chamber design may be used also in other experimental applications with a demand for low material budget, tracking capability, and the need for dE/dx particle identification, all while in the presence of a relatively high particle flux

Results of the 2022 ECFA Early-Career Researchers Panel survey on career prospects and diversity

International audienceThis document presents the outcomes of a comprehensive survey conducted among early career researchers (ECRs) in academic particle physics. Running from September 24, 2022, to March 3, 2023, the survey gathered responses from 759 ECRs employed in 39 countries. The study aimed to gain insights into the career prospects and experiences of ECRs while also delving into diversity and sociological aspects within particle physics research. The survey results are presented in a manner consistent with the survey choices. The document offers insights for the particle physics community, and provides a set of recommendations for enhancing career prospects, fostering diversity, and addressing sociological dimensions within this field