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, Volume:
755
Journal Article
Peer reviewed
Open access
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.
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.
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, Volume:
499, Issue:
2
Journal Article
Peer reviewed
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.
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 ...Z0-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 Z0-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.
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, Volume:
61, Issue:
4
Journal Article, Conference Proceeding
Peer reviewed
Open access
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.
Bose-Einstein correlations between charged pion and ital Ksup + pairs are calculated using the space-time and four-momentum distributions from relativistic quantum molecular dynamics for 200 ...GeV/nucleon sup 32ital S+Pb and compared to pion correlation measurements from two CERN experiments. Good agreement is found. The predicted apparent radii from the ital Ksup + correlation functions are smaller than the corresponding pion radii.
Two-particle correlations of negative pions as a function of charged particle multiplicity are studied in Pb+Pb collisions at \(\sqrt{s}=17.3\)GeV per nucleon using the NA44 experiment at the CERN ...Super Proton Synchrotron(SPS). We find that the source size parameters increase with the charged particle multiplicity. However the slope of the source size parameters plotted as a function of charged multiplicity is slightly larger at high multiplicity than at low multiplicity. The value of \(\lambda\) is independent of charged multiplicity. For Pb+Pb collisions, \(R_L\) is larger than \(R_{TS}\) and \(R_{TO}\) for all multiplicity intervals, whereas these three radius parameters were approximately equal in S+Nucleus collisions. The ratios (\(R_L/R_{TS}\)) and (\(R_L/R_{TO}\)) for Pb+Pb data show almost no dependence on charged multiplicity. The duration of pion emission \(\Delta \tau\) is constant at 3.8\(\pm\)1.1 fm/c as a function of the charged multiplicity in Pb+Pb collisions. Effective volume (V) is also calculated as V=\(\pi\times R_{TS}^2\times R_L\), assuming a cylindrically shaped source. We found, within the limited statistics, the effective volume rapidly increases at high multiplicity.
Hard Probe Results from PHENIX van Hecke, H.
Nuclear and particle physics proceedings,
July-September 2016, 2016-07-00, Volume:
276-278
Journal Article
Peer reviewed
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.
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