The study of open charm meson production provides an efficient tool for the investigation of the properties of hot and dense matter formed in nucleus–nucleus collisions. The interpretation of the ...existing di-muon data from the CERN SPS suffers from a lack of knowledge on the mechanism and properties of the open charm particle production. Due to this, the heavy-ion programme of the NA61/SHINE experiment at the CERN SPS has been extended by precise measurements of charm hadrons with short lifetimes. A new Vertex Detector for measurements of the rare processes of open charm production in nucleus–nucleus collisions was designed to meet the challenges of track registration and high resolution in primary and secondary vertex reconstruction. A small-acceptance version of the vertex detector was installed in 2016 and tested with Pb + Pb collisions at 150
A
GeV
/
c
. It was also operating during the physics data taking on Xe + La and Pb + Pb collisions at 150
A
GeV
/
c
conducted in 2017 and 2018. This paper presents the detector design and construction, data calibration, event reconstruction, and analysis procedure.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This paper presents measurements of production cross sections and inelastic cross sections for the following reactions: 60 GeV/c protons with C, Be, Al targets and 120 GeV/c protons with C and Be ...targets. The analysis is performed using the NA61/SHINE spectrometer at the CERN Super Proton Synchrotron. First measurements are obtained using protons at 120 GeV/c, while the results for protons at 60 GeV/c are compared with previously published measurements. These interaction cross section measurements are critical inputs for neutrino flux prediction in current and future accelerator-based long-baseline neutrino experiments.
Pentaquark states have been extensively investigated theoretically in the context of the constituent quark model. In this paper results of an experimental search for pentaquarks in the Ξ−π−, Ξ−π+, ...¯Ξ+π− and ¯ Ξ+π+ invariant mass spectra in proton-proton interactions at √s = 17.3 GeV are presented. Previous possible evidence from the NA49 collaboration of the existence of a narrow Ξ−π− baryon resonance in p + p interactions is not confirmed with almost 10 times greater event statistics. The search was performed using the NA61/SHINE detector which reuses the main components of the NA49 apparatus. No signal was observed with either the selection cuts of NA49 or newly optimized cuts.
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 (10−100kHz) 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.
Charmonium production in heavy ion collisions is considered as an important diagnostic probe for studying the phase diagram of strongly interacting matter for potential phase transitions. The ...interpretation of existing data from the CERN SPS is hampered by a lack of knowledge on the properties of open charm particle production in the fireball. Moreover, open charm production in heavy ion collisions by itself is poorly understood. To overcome this obstacle, the NA61/SHINE was equipped with a Small Acceptance Vertex Detector (SAVD), which is predicted to make the experiment sensitive to open charm mesons produced in A-A collisions at the SPS top energy. This paper will introduce the concept and the hardware of the SAVD. Moreover, first running experience as obtained in a commissioning run with a 150
A
GeV/
c
Pb+Pb collision system will be reported.
Charmonium production in heavy ion collisions is considered as an important diagnostic probe for studying the phase diagram of strongly interacting matter for potential phase transitions. The ...interpretation of existing data from the CERN SPS is hampered by a lack of knowledge on the properties of open charm particle production in the fireball. Moreover, open charm production in heavy ion collisions by itself is poorly understood. To overcome this obstacle, the NA61/SHINE was equipped with a Small Acceptance Vertex Detector (SAVD), which is predicted to make the experiment sensitive to open charm mesons produced in A-A collisions at the SPS top energy. This paper will introduce the concept and the hardware of the SAVD. Moreover, first running experience as obtained in a commissioning run with a 150 AGeV/c Pb+Pb collision system will be reported.
The NA61/SHINE experiment at the CERN Super Proton Synchrotron (SPS) studies the onset of deconfinement in hadron matter by a scan of particle production in collisions of nuclei with various sizes at ...a set of energies covering the SPS energy range. This paper presents results on inclusive double-differential spectra, transverse momentum and rapidity distributions and mean multiplicities of Formula omitted, Formula omitted, p and Formula omitted produced in the 20% most central Formula omittedBe+ Formula omittedBe collisions at beam momenta of 19A, 30A, 40A, 75A and 150A Formula omitted. The energy dependence of the Formula omitted/ Formula omitted ratios as well as of inverse slope parameters of the Formula omitted transverse mass distributions are close to those found in inelastic p+p reactions. The new results are compared to the world data on p+p and Pb+Pb collisions as well as to predictions of the Epos, Urqmd, Ampt, Phsd and Smash models.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A measurement of charged hadron pair correlations in two-dimensional Formula omitted space is presented. The analysis is based on total 30 million central Be + Be collisions observed in the ...NA61/SHINE detector at the CERN SPS for incident beam momenta of 19A, 30A, 40A, 75A, and 150A Formula omitted. Measurements were carried out for unlike-sign and like-sign charge hadron pairs independently. The Formula omitted correlation functions were compared with results from a similar analysis on p + p interactions at similar beam momenta per nucleon. General trends of the back-to-back correlations are similar in central Be + Be collisions and p + p interactions, but are suppressed in magnitude due to the increased combinatorial background. Predictions from the Epos and UrQMD models are compared to the measurements. Evolution of an enhancement around Formula omitted with incident energy is observed in central Be + Be collisions. It is not predicted by both models and almost non-existing in proton-proton collisions at the same momentum per nucleon.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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