The evaluation of the measurement of double-spin asymmetries for charge-separated pions and kaons produced in deep-inelastic scattering from the proton using the ECCE detector design concept is ...presented, for the combinations of lepton and hadron beam energies of 5 × 41 GeV2 and 18 × 275 GeV2. The study uses unpolarised simulated data that are processed through a full GEANT simulation of the detector. These data are then reweighted at the parton level with DSSV helicity distributions and DSS fragmentation functions, in order to generate the relevant asymmetries, and subsequently analysed. The performed analysis shows that the ECCE detector concept provides the resolution and acceptance, with a broad coverage in kinematic phase space, needed for a robust extraction of asymmetries. This, in turn, allows for a precise extraction of sea-quark helicity distributions.
Advanced detector R&D requires performing computationally intensive and detailed simulations as part of the detector-design optimization process. We propose a general approach to this process based ...on Bayesian optimization and machine learning that encodes detector requirements. As a case study, we focus on the design of the dual-radiator Ring Imaging Cherenkov (dRICH) detector under development as a potential component of the particle-identification system at the future Electron-Ion Collider (EIC). The EIC is a US-led frontier accelerator project for nuclear physics, which has been proposed to further explore the structure and interactions of nuclear matter at the scale of sea quarks and gluons. We show that the detector design obtained with our automated and highly parallelized framework outperforms the baseline dRICH design within the assumptions of the current model. Our approach can be applied to any detector R&D, provided that realistic simulations are available.
The PHENIX Forward Silicon Vertex Detector Aidala, C.; Anaya, L.; Anderssen, E. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2014, Letnik:
755
Journal Article
Recenzirano
Odprti dostop
A new silicon detector has been developed to provide the PHENIX experiment with precise charged particle tracking at forward and backward rapidity. The Forward Silicon Vertex Tracker (FVTX) was ...installed in PHENIX prior to the 2012 run period of the Relativistic Heavy Ion Collider (RHIC). The FVTX is composed of two annular endcaps, each with four stations of silicon mini-strip sensors, covering a rapidity range of 1.2<|η|<2.2 that closely matches the two existing PHENIX muon arms. Each station consists of 48 individual silicon sensors, each of which contains two columns of mini-strips with 75μm pitch in the radial direction and lengths in the ϕ direction varying from 3.4mm at the inner radius to 11.5mm at the outer radius. The FVTX has approximately 0.54million strips in each endcap. These are read out with FPHX chips, developed in collaboration with Fermilab, which are wire bonded directly to the mini-strips. The maximum strip occupancy reached in central Au–Au collisions is approximately 2.8%. The precision tracking provided by this device makes the identification of muons from secondary vertices away from the primary event vertex possible. The expected distance of closest approach (DCA) resolution of 200μm or better for particles with a transverse momentum of 5 GeV/c will allow identification of muons from relatively long-lived particles, such as D and B mesons, through their broader DCA distributions.
Thin film composite poly1-(trimethylsilyl)-1-propyne – PTMSP – pervaporation membranes have been investigated for in-situ product recovery of n-butanol from a fermentation broth using a Clostridium ...acetobutylicum strain. For this specific application, a strong flux decline is observed which can be attributed to ageing and fouling phenomena in the membrane. In order to have a better understanding of these complex phenomena, X-ray photoelectron spectroscopy and infra-red spectroscopy have been used to monitor the ageing of the PTMSP membranes under different steady state conditions. The fouling effect of different components in the fermentation broth has been systematically investigated through off-line pervaporation tests on model mixtures with stepwise addition of fermentation by-products, revealing the negative impact of butyric acid and long chain fatty acids on the permeate flux. Additionally, long chain fatty acids, such as stearic acid, impact negatively the butanol/water separation factor. In order to remedy or at least decrease the impact of this fouling issue, the integration of an upstream nanofiltration step has been evaluated. This pre-treatment step has led to a drastic improvement of the flux through the filled PTMSP membrane (factor 4), while the butanol–water separation factor (27.5) remained much higher than the separation factor obtained with a commercial PDMS membrane (14.7).
•The ageing of PTMSP composite membranes was followed by XPS and IR measurements.•Stepwise addition of fouling components was studied by off-line pervaporation tests.•Flux decrease was observed during in-line ISPR of n-butanol through the PTMSP membrane.•The incorporation of a nanofiltration pre-treatment step was investigated.•Improved flux properties were obtained with optimum BuOH/H2O separation factors.
Hard Probe Results from PHENIX van Hecke, H.
Nuclear and particle physics proceedings,
July-September 2016, 2016-07-00, Letnik:
276-278
Journal Article
Recenzirano
We report on selected recent results from the PHENIX collaboration. For thermal photons, total yields and flow coefficients in sNN=200 GeV Au+Au collisions are reported. Results from small systems ...(d+Au and 3He+Au) colliding at sNN=200 GeV show collective behavior for transverse momenta up to approximately 6 GeV/c. How small systems develop collective behavior remains a challenge for modelers.
Experimental studies of the collisions of heavy nuclei at relativistic energies have established the properties of the quark–gluon plasma (QGP), a state of hot, dense nuclear matter in which quarks ...and gluons are not bound into hadrons1–4. In this state, matter behaves as a nearly inviscid fluid5 that efficiently translates initial spatial anisotropies into correlated momentum anisotropies among the particles produced, creating a common velocity field pattern known as collective flow. In recent years, comparable momentum anisotropies have been measured in small-system proton–proton (p+p) and proton–nucleus (p+A) collisions, despite expectations that the volume and lifetime of the medium produced would be too small to form a QGP. Here we report on the observation of elliptic and triangular flow patterns of charged particles produced in proton–gold (p+Au), deuteron–gold (d+Au) and helium–gold (3He+Au) collisions at a nucleon–nucleon centre-of-mass energy \\sqrt {s_{{\mathrm{NN}}}\ = 200 GeV. The unique combination of three distinct initial geometries and two flow patterns provides unprecedented model discrimination. Hydrodynamical models, which include the formation of a short-lived QGP droplet, provide the best simultaneous description of these measurements.
PHENIX inner detectors Allen, M.; Bennett, M.J.; Bobrek, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2003, Letnik:
499, Številka:
2
Journal Article
Recenzirano
The timing, location and particle multiplicity of a PHENIX collision are determined by the Beam–Beam Counters (BBC), the Multiplicity/Vertex Detector (MVD) and the Zero-Degree Calorimeters (ZDC). The ...BBCs provide both the time of interaction and position of a collision from the flight time of prompt particles. The MVD provides a measure of event particle multiplicity, collision vertex position and fluctuations in charged particle distributions. The ZDCs provide information on the most grazing collisions. A Normalization Trigger Counter (NTC) is used to obtain absolute cross-section measurements for p–p collisions. The BBC, MVD and NTC are described below.
Z0-tagged quark jets at the large hadron collider Kunde, G. J.; van Hecke, H.; Hessler, K. ...
European physical journal. C, Particles and fields (Print),
2009/6, Letnik:
61, Številka:
4
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
The Large Hadron Collider will allow studies of hard probes in nucleus-nucleus collisions which were not accessible at the Relativistic Heavy Ion Collider—even the study of small cross-section
Z
0
...-tagged jets becomes possible. Going beyond the measurement of back-to-back correlations of two strongly interacting particles to measure plasma properties, we replace one side by an electromagnetic probe which propagates through the plasma undisturbed and therefore provides a measurement of the energy of the initial hard scattering. We show that at sufficiently high transverse momentum the
Z
0
-tagged jets originate predominately from the fragmentation of quarks and anti-quarks while gluon jets are suppressed. We propose to use lepton-pair tagged jets to study medium-induced partonic energy loss and to measure in-medium parton fragmentation functions to determine the opacity of the quark gluon plasma.
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