Explore the vast range of titles available.

The Fourier harmonics, v 2 and v 3 of negative pions are measured at center-of-mass energy per nucleon pair of s NN = 17.3 GeV around midrapidity by the CERES/NA45 experiment at the CERN SPS in 0–30% central PbAu collisions with a mean centrality of 5.5%. The analysis is performed in two centrality bins as a function of the transverse momentum p T from 0.05 GeV/ c to more than 2 GeV/ c . This is the first measurement of the v 3 1 / 3 / v 2 1 / 2 ratio as a function of transverse momentum at SPS energies, that reveals, independently of the hydrodynamic models, hydrodynamic behavior of the formed system. For p T above 0.5 GeV/ c , the ratio is nearly flat in accordance with the hydrodynamic prediction and as previously observed by the ATLAS and ALICE experiments at the much higher LHC energies. The results are also compared with the SMASH-vHLLE hybrid model predictions, as well as with the SMASH model applied alone.

Abstract The Fourier harmonics,$$v_2$$v 2 and$$v_3$$v 3 of negative pions are measured at center-of-mass energy per nucleon pair of$$\\sqrt{s_{\\textrm{NN}}}$$s NN = 17.3 GeV around midrapidity by the CERES/NA45 experiment at the CERN SPS in 0–30% central PbAu collisions with a mean centrality of 5.5%. The analysis is performed in two centrality bins as a function of the transverse momentum$$\\mathrm {p_{\\textrm{T}}}$$p T from 0.05 GeV/c to more than 2 GeV/c. This is the first measurement of the$$v^{1/3}_{3}/v^{1/2}_{2}$$v 3 1 / 3 / v 2 1 / 2 ratio as a function of transverse momentum at SPS energies, that reveals, independently of the hydrodynamic models, hydrodynamic behavior of the formed system. For$$\\mathrm {p_{\\textrm{T}}}$$p T above 0.5 GeV/c, the ratio is nearly flat in accordance with the hydrodynamic prediction and as previously observed by the ATLAS and ALICE experiments at the much higher LHC energies. The results are also compared with the SMASH-vHLLE hybrid model predictions, as well as with the SMASH model applied alone.

We present the combined results on electron-pair production in 158 GeV/n Pb-Au (\\(\\sqrt{s}\\) = 17.2 GeV) collisions taken at the CERN SPS in 1995 and 1996, and give a detailed account of the data analysis. The enhancement over the reference of neutral meson decays amounts to a factor of 2.31 \\(\\pm0.19 (stat.)\\pm0.55 (syst.)\\pm0.69 (decays)\\) for semi-central collisions (28\\(\\%\\)\\(\\sigma/\\sigma_{geo}\\)) when yields are integrated over m > 200 MeV/c2 in invariant mass. The measured yield, its stronger-than-linear scaling with \\(N_{\\rm ch}\\), and the dominance of low pair pt strongly suggest an interpretation as thermal radiation from pion annihilation in the hadronic fireball. The shape of the excess centring at \\(m\\approx\\) 500 MeV/c2, however, cannot be described without strong medium modifications of the \\(\\rho\\) meson. The results are put into perspective by comparison to predictions from Brown-Rho scaling governed by chiral symmetry restoration, and from the spectral-function many-body treatment in which the approach to the phase boundary is less explicit.

We present a comparative study of three resistive Micro-Pattern Gaseous Detector (MPGD) technologies - Micromegas, RPWELL, and \\(\\mu\\mathrm{-RWELL}\\) - with VMM3a based readout, using relativistic muons and pions. The Micromegas and the RPWELL were operated in \\(\\mathrm{Ar/CO_2/iC_4H_{10}}\\) gas mixture, while the \\(\\mu\\mathrm{-RWELL}\\) in \\(\\mathrm{Ar/CO_2/CF_4}\\) (greenhouse gas containing mixture). All detectors operated stably exceeding 96% efficiency. The usage of continuous readout enabled studies of detector electrical instabilities in- and off-beam at near breakdown voltages. Each technology has different advantages making it more suitable for various experimental conditions.

A study of elliptic flow and two-particle azimuthal correlations of charged particles (\\(0.5 < p_{{\\text{T}}} < 2.5\\) GeV/c) and high-\\(p_{\\rm T}\\) pions (\\(1.2 < p_{{\\text{T}}} < 3.5\\) GeV/c) in Pb + Au collisions at 158A GeV/c, close to midrapidity, is presented. Elliptic flow (v2) rises linearly with \\(p_{\\rm T}\\) to a value of about 10\\(\\%\\) at 2 GeV/c. Beyond \\(p_{\\rm T}\\approx\\) 1.5 GeV/c, the slope decreases and possibly indicates a v2 saturation at high \\(p_{\\rm T}\\). Two-pion azimuthal anisotropies for \\(p_{\\rm T} > \\) 1.2 GeV/c exceed the v2 values by about 60\\(\\%\\) in semicentral collisions. This non-flow component is attributed to near-side and away-side jetlike correlations. While the near-side peak remains constant with centrality 0.23\\(\\pm\\)0.03 rad, as expected for fragmentation, the away-side peak experiences broadening and disappears in central collisions.

The increase in luminosity, and consequent higher backgrounds, of the LHC upgrades require improved rejection of fake tracks in the forward region of the ATLAS Muon Spectrometer. The New Small Wheel upgrade of the Muon Spectrometer aims to reduce the large background of fake triggers from track segments that are not originated from the interaction point. The New Small Wheel employs two detector technologies, the resistive strip Micromegas detectors and the \"small\" Thin Gap Chambers, with a total of 2.45 Million electrodes to be sensed. The two technologies require the design of a complex electronics system given that it consists of two different detector technologies and is required to provide both precision readout and a fast trigger. It will operate in a high background radiation region up to about 20 kHz/cm\\(^{2}\\) at the expected HL-LHC luminosity of \\(\\mathcal{L}\\)=7.5\\(\\times10^{34}\\)cm\\(^{-2}\\)s\\(^{-1}\\). The architecture of the system is strongly defined by the GBTx data aggregation ASIC, the newly-introduced FELIX data router and the software based data handler of the ATLAS detector. The electronics complex of this new detector was designed and developed in the last ten years and consists of multiple radiation tolerant Application Specific Integrated Circuits, multiple front-end boards, dense boards with FPGA's and purpose-built Trigger Processor boards within the ATCA standard. The New Small Wheel has been installed in 2021 and is undergoing integration within ATLAS for LHC Run 3. It should operate through the end of Run 4 (December 2032). In this manuscript, the overall design of the New Small Wheel electronics is presented.

The Fourier harmonics, \\(v_2\\) and \\(v_3\\) of negative pions are measured at center-of-mass energy per nucleon pair of \\(\\sqrt{s_{\\mathrm{NN}}}\\)= 17.3 GeV around midrapidity by the CERES/NA45 experiment at the CERN SPS in 0--30\\% central PbAu collisions with a mean centrality of 5.5\\%. The analysis is performed in two centrality bins as a function of the transverse momentum \\(\\mathrm{p_{\\mathrm{T}}}\\) from 0.05 GeV/\\(c\\) to more than 2 GeV/\\(c\\). This is the first measurement of the \\(v^{1/3}_{3}/v^{1/2}_{2}\\) ratio as a function of transverse momentum at SPS energies, that reveals, independently of the hydrodynamic models, hydrodynamic behavior of the formed system. For \\(\\mathrm{p_{\\mathrm{T}}}\\) above 0.5 GeV/\\(c\\), the ratio is nearly flat in accordance with the hydrodynamic prediction and as previously observed by the ATLAS and ALICE experiments at the much higher LHC energies. The results are also compared with the SMASH-vHLLE hybrid model predictions, as well as with the SMASH model applied alone.

A novel Hadron Blind Detector (HBD) has been developed for an upgrade of the PHENIX experiment at RHIC. The HBD will allow a precise measurement of electron-positron pairs from the decay of the light vector mesons and the low-mass pair continuum in heavy-ion collisions. The detector consists of a 50 cm long radiator filled with pure CF4 and directly coupled in a windowless configuration to a triple Gas Electron Multiplier (GEM) detector with a CsI photocathode evaporated on the top face of the first GEM foil.

We propose a new fixed-target experiment for the study of electromagnetic and hard probes of the Quark-Gluon Plasma (QGP) in heavy-ion collisions at the CERN SPS. The experiment aims at performing measurements of the dimuon spectrum from threshold up to the charmonium region, and of hadronic decays of charm and strange hadrons. It is based on a muon spectrometer, which includes a toroidal magnet and six planes of tracking detectors, coupled to a vertex spectrometer, equipped with Si MAPS immersed in a dipole field. High luminosity is an essential requirement for the experiment, with the goal of taking data with 10\\(^6\\) incident ions/s, at collision energies ranging from \\(\\sqrt{s_{\\rm NN}} = 6.3\\) GeV (\\(E_{\\rm lab}= 20\\) A GeV) to top SPS energy (\\(\\sqrt{s_{\\rm NN}} = 17.3\\) GeV, \\(E_{\\rm lab}= 158\\) A GeV). This document presents the physics motivation, the foreseen experimental set-up including integration and radioprotection studies, the current detector choices together with the status of the corresponding R&D, and the outcome of physics performance studies. A preliminary cost evaluation is also carried out.