Browsing by Subject "DETECTOR"

Sort by: Order: Results:

Now showing items 1-20 of 20
  • Aidala, C.; Kim, D. J.; Krizek, F.; Novitzky, N.; Rak, J.; PHENIX Collaboration (2017)
    The fraction of J/psi mesons which come from B-meson decay, F-B -> J/psi is measured for J/psi rapidity 1.2 <|y| <2.2 and p(T) > 0 in p + p and Cu+Au collisions at root s(NN) = 200 GeV with the PHENIX detector. The extracted fraction is F-B -> J/psi = 0.025 +/- 0.006 (stat) +/- 0.010(syst) for p + p collisions. For Cu+Au collisions, F-B -> J/psi is 0.094 +/- 0.028(stat) +/- 0.037(syst) in the Au-going direction (-2.2 <y <-1.2) and 0.089 +/- 0.026(stat) +/- 0.040(syst) in the Cu-going direction (1.2 <y <2.2). The nuclear modification factor, R-CuAu,of B mesons in Cu+Au collisions is consistent with binary scaling of measured yields in p + p at both forward and backward rapidity.
  • The ALICE collaboration; Acharya, S.; Brucken, E. J.; Chang, B.; Hilden, T. E.; Kim, D. J.; Litichevskyi, V.; Mieskolainen, M. M.; Orava, R.; Parkkila, J. E.; Rak, J.; Räsänen, S. S.; Saarinen, S.; Slupecki, M.; Snellman, T. W.; Trzaska, W. H.; Vargyas, M.; Viinikainen, J. (2019)
    The procedure for the energy calibration of the high granularity electromagnetic calorimeter PHOS of the ALICE experiment is presented. The methods used to perform the relative gain calibration, to evaluate the geometrical alignment and the corresponding correction of the absolute energy scale, to obtain the nonlinearity correction coefficients and finally, to calculate the time-dependent calibration corrections, are discussed and illustrated by the PHOS performance in proton-proton (pp) collisions at root s = 13 TeV. After applying all corrections, the achieved mass resolutions for pi(0) and eta mesons for p(T) > 1.7 GeV/c are sigma(pi 0)(m) = 4.56 +/- 0.03 MeV/c(2) and sigma(eta)(m) = 15.3 +/- 1.0 MeV/c(2), respectively.
  • The CMS collaboration; Sirunyan, A. M.; Eerola, P.; Kirschenmann, H.; Pekkanen, J.; Voutilainen, M.; Havukainen, J.; Heikkilä, J. K.; Järvinen, T.; Karimäki, V.; Kinnunen, R.; Lampén, T.; Lassila-Perini, K.; Laurila, S.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Siikonen, H.; Tuominen, E.; Tuominiemi, J.; Tuuva, T. (2018)
    The transverse momentum balance of pairs of back-to-back b quark jets in PbPb and pp collisions recorded with the CMS detector at the LHC is reported. The center-of-mass energy in both collision systems is 5.02 TeV per nucleon pair. Compared to the pp collision baseline, b quark jets have a larger imbalance in the most central PbPb collisions, as expected from the jet quenching effect. The data are also compared to the corresponding measurement with inclusive dijets. In the most central collisions, the imbalance of b quark dijets is comparable to that of inclusive dijets.
  • Viinamaki, Jenni; Ojanpera, Ilkka (2016)
    There is a constant demand for the quantification of drug metabolites within post-mortem toxicology. Especially electrospray ionization-mass spectrometry techniques necessitate that calibration is carried out using primary reference standards due to the non-uniform ionization efficiency between parent drugs and their metabolites. As reference standards for metabolites are not readily available and their costs are high, alternative methods for immediate quantification are required. In this study, ultra-high performance liquid chromatography coupled with photodiode array detection and corona charged aerosol detection was utilized for the concurrent quantification of 23 drug metabolites using the corresponding parent drug for calibration. Based on this secondary calibration, the quantitative results for the N-demethylated metabolites by each detector were similar to those obtained by the ordinary calibration using reference standards. For O-demethylated metabolites, the differences in detector response caused somewhat larger biases using the secondary calibration. Using the validated secondary calibration, the blood sample data gathered from 633 post-mortem cases was retrospectively reprocessed to discover the combined metabolite-parent concentrations and metabolite to parent ratios for six toxicologically relevant drugs. These results, representing all causes of death, were compared to published data from therapeutic drug monitoring and post-mortem toxicology. (C) 2016 Elsevier Ireland Ltd. All rights reserved.
  • PHENIX Collaboration; Adare, A.; Kim, D. J.; Krizek, F.; Novitzky, N.; Rak, J. (2018)
    We have measured the cross section and single-spin asymmetries from forward W-+/- -> mu(+/-)nu production in longitudinally polarized p + p collisions at root s = 510 GeV using the PHENIX detector at the Relativistic Heavy Ion Collider. The cross sections are consistent with previous measurements at this collision energy, while the most forward and backward longitudinal single spin asymmetries provide new insights into the sea quark helicities in the proton. The charge of the W bosons provides a natural flavor separation of the participating partons.
  • MINIBALL Collaboration; HIE-ISOLDE Collaboration; Rosiak, D.; Seidlitz, M.; Reiter, P.; Naidja, H.; Tsunoda, Y.; Togashi, T.; Nowacki, F.; Otsuka, T.; Colo, G.; Arnswald, K.; Berry, T.; Blazhev, A.; Borge, M. J. G.; Cederkall, J.; Cox, D. M.; De Witte, H.; Gaffney, L. P.; Henrich, C.; Hirsch, R.; Huyse, M.; Illana, A.; Johnston, K.; Kaya, L.; Kroell, Th.; Benito, M. L. Lozano; Ojala, J.; Pakarinen, J.; Queiser, M.; Rainovski, G.; Rodriguez, J. A.; Siebeck, B.; Siesling, E.; Snall, J.; Van Duppen, P.; Vogt, A.; von Schmid, M.; Warr, N.; Wenander, F.; Zell, K. O. (2018)
    The first 2(+) and 3(-) states of the doubly magic nucleus Sn-132 are populated via safe Coulomb excitation employing the recently commissioned HIE-ISOLDE accelerator at CERN in conjunction with the highly efficient MINIBALL array. The Sn-132 ions are accelerated to an energy of 5.49 MeV/nucleon and impinged on a Pb-206 target. Deexciting gamma rays from the low-lying excited states of the target and the projectile are recorded in coincidence with scattered particles. The reduced transition strengths are determined for the transitions 0(g.s)(+) -> 2(1)(+), 0(g.s)(+) -> 3(1)(-), and 2(1)(+) -> 3(1)(-) in Sn-132. The results on these states provide crucial information on cross-shell configurations which are determined within large-scale shell-model and Monte Carlo shell-model calculations as well as from random-phase approximation and relativistic random-phase approximation. The locally enhanced B(E2; 0(g.s)(+) -> 2(1)(+)) strength is consistent with the microscopic description of the structure of the respective states within all theoretical approaches. The presented results of experiment and theory can be considered to be the first direct verification of the sphericity and double magicity of Sn-132.
  • Pathak, Harshad; Spah, Alexander; Kim, Kyung Hwan; Tsironi, Ifigeneia; Mariedahl, Daniel; Blanco, Maria; Huotari, Simo; Honkimäki, Veijo; Nilsson, Anders (2019)
    Wide angle x-ray scattering of supercooled water down to 234.8 K was studied using high energy x rays at the European Synchrotron Radiation Facility. The oxygen-oxygen pair distribution function (PDF) was calculated from the scattering pattern out to the 5th peak at an intermolecular distance, r approximate to 11 angstrom. We observe that the 4th peak and the 5th peak in the PDF increase in height upon supercooling. We also observe that the 4th peak position (r(4)) shifts to shorter distances upon supercooling consistent with previous studies, but we see a more rapid change at the lowest temperature. The running oxygen-oxygen coordination number is calculated for 5 different temperatures, and an isosbestic point at r(iso) = 3.31 +/- 0.05 angstrom was found corresponding to a coordination number of 4.39 +/- 0.15. The comparison of the PDF of the coldest water with that of amorphous ice shows distinct differences. We propose that there are 5-member pentamer rings in low density liquid-like structures giving rise to the sharp correlations at r approximate to 9 angstrom and r approximate to 11 angstrom.
  • Angileri, Axel; Sardini, Paul; Donnard, Jerome; Duval, Samuel; Lefeuvre, Hugo; Oger, Tugdual; Patrier, Patricia; Rividi, Nicolas; Siitari-Kauppi, Marja; Toubon, Herve; Descostes, Michael (2018)
    A new approach is proposed in order to spatially localize and determine the equilibrium state of natural decay chains on hand-scale geological samples, thanks to a combination of three techniques: 1) Elementary chemical mapping by microprobe; 2) Alpha autoradiograph by gaseous detectors and 3) bulk alpha particle spectrometry. The quantitative nature of alpha autoradiograph and its comparison with U chemical maps allows to locate radioactive equilibrium state in four samples. This equilibrium state was confirmed by alpha spectrometry analysis.
  • Acharya, S.; Brucken, E. J.; Chang, B.; Kim, D. J.; Litichevskyi, V.; Mieskolainen, M. M.; Orava, R.; Rak, J.; Räsänen, S. S.; Snellman, T. W.; Trzaska, W. H.; Viinikainen, J.; The ALICE collaboration (2017)
    The production cross sections for prompt charmed mesons D-0, D+, D*(+) and D-s(+) were measured at mid-rapidity in proton-proton collisions at a centre-of-mass energy root s = 7 TeV with the ALICE detector at the Large Hadron Collider (LHC). D mesons were reconstructed from their decays D-0 -> K-pi(+), D+ -> K- pi(+)pi(+), D*(+) -> D-0 pi(+), D-s(+) -> phi pi(+) -> K-K+pi(+), and their charge conjugates. With respect to previous measurements in the same rapidity region, the coverage in transverse momentum (p(T)) is extended and the uncertainties are reduced by a factor of about two. The accuracy on the estimated total c (c) over bar production cross section is likewise improved. The measured p(T)-differential cross sections are compared with the results of three perturbative QCD calculations.
  • Adam, J.; Brucken, E. J.; Chang, B.; Hilden, T. E.; Kim, D. J.; Kral, J.; Mieskolainen, M. M.; Orava, R.; Rak, J.; Slupecki, M.; Snellman, T. W.; Trzaska, W. H.; Vargyas, M.; Viinikainen, J.; Räsänen, Sami Sakari; The ALICE collaboration (2015)
    We report the measurement of a new observable of jet quenching in central Pb-Pb collisions at root s(NN) = 2.76 TeV, based on the semi-inclusive rate of charged jets recoiling from a high transverse momentum (high-p T) charged hadron trigger. Jets are measured using collinear-safe jet reconstruction with infrared cutoff for jet constituents of 0.15 GeV, for jet resolution parameters R = 0.2, 0.4 and 0.5. Underlying event background is corrected at the event-ensemble level, without imposing bias on the jet population. Recoil jet spectra are reported in the range 20 <p(T,jet)(ch) <100 GeV. Reference distributions for pp collisions at root s = 2.76TeV are calculated using Monte Carlo and NLO pQCD methods, which are validated by comparing with measurements in pp collisions at root s = 7TeV. The recoil jet yield in central Pb-Pb collisions is found to be suppressed relative to that in pp collisions. No significant medium-induced broadening of the intra-jet energy profile is observed within 0.5 radians relative to the recoil jet axis. The angular distribution of the recoil jet yield relative to the trigger axis is found to be similar in central Pb-Pb and pp collisions, with no significant medium-induced acoplanarity observed. Large-angle jet deflection, which may provide a direct probe of the nature of the quasi-particles in hot QCD matter, is explored.
  • Aidala, C.; Kim, D. J.; PHENIX Collaboration (2017)
    We present measurements of long-range angular correlations and the transverse momentum dependence of elliptic flow v(2) in high-multiplicity p + Au collisions at root S-NN = 200 GeV. A comparison of these results to previous measurements in high-multiplicity d + Au and He-3+Au collisions demonstrates a relation between v(2) and the initial collision eccentricity epsilon(2), suggesting that the observed momentum-space azimuthal anisotropies in these small systems have a collective origin and reflect the initial geometry. Good agreement is observed between the measured v(2) and hydrodynamic calculations for all systems, and an argument disfavoring theoretical explanations based on initial momentum-space domain correlations is presented. The set of measurements presented here allows us to leverage the distinct intrinsic geometry of each of these systems to distinguish between different theoretical descriptions of the long-range correlations observed in small collision systems.
  • Aaltonen, T.; Brucken, E.; Devoto, F.; Mehtala, P.; Orava, R.; CDF Collaboration (2016)
    We report a measurement of the forward-backward asymmetry, A(FB), in b (b) over bar pairs produced in proton-antiproton collisions and identified by muons from semileptonic b-hadron decays. The event sample is collected at a center-of-mass energy of root s = 1.96 TeV with the CDF II detector and corresponds to 6.9 fb(-1) of integrated luminosity. We obtain an integrated asymmetry of A(FB)(b (b) over bar) = (1.2 +/- 0.7)% at the particle level for b-quark pairs with invariant mass, m(b (b) over bar), down to 40 GeV/c(2) and measure the dependence of A(FB)(b (b) over bar) on m(b (b) over bar). The results are compatible with expectations from the standard model.
  • Aaltonen, T.; Albrow, M. G.; Brucken, E.; Devoto, F.; Mehtala, P.; Orava, R.; CDF Collaboration (2017)
    A measurement of the inclusive production cross section of isolated prompt photons in proton-antiproton collisions at center-of-mass energy root s = 1.96 TeV is presented. The results are obtained using the full Run II data sample collected with the Collider Detector at the Fermilab Tevatron, which corresponds to an integrated luminosity of 9.5 fb(-1). The cross section is measured as a function of photon transverse energy, E-T(gamma), in the range 30 <E-T(gamma) <500 GeV and in the pseudorapidity region |eta(gamma)| <1.0. The results are compared with predictions from parton-shower Monte Carlo models at leading order in QCD and from next-to-leading-order perturbative QCD calculations. The latter show good agreement with the measured cross section.
  • Aidala, C.; Kim, D. J.; PHENIX Collaboration (2017)
    We present measurements of the elliptic flow (v(2)) as a function of transverse momentum (p(T)), pseudorapidity (eta), and centrality in d + Au collisions at root s(NN) = 200, 62.4, 39, and 19.6 GeV. The beam-energy scan of d + Au collisions provides a testing ground for the onset of flow signatures in small collision systems. We measure a nonzero v(2) signal at all four collision energies, which, at midrapidity and low p(T), is consistent with predictions from viscous hydrodynamic models. Comparisons with calculations from parton transport models (based on the AMPT Monte Carlo generator) show good agreement with the data at midrapidity to forward (d-going) rapidities and low p(T). At backward (Au-going) rapidities and p(T) > 1.5GeV/c, the data diverges from AMPT calculations of v(2) relative to the initial geometry, indicating the possible dominance of nongeometry related correlations, referred to as nonflow. We also present measurements of the charged-particle multiplicity (d N-ch/d eta) as a function of eta in central d + Au collisions at the same energies. We find that in d + Au collisions at root s(NN) = 200 GeV the v(2) scales with d N-ch/d eta over all eta in the PHENIX acceptance. At root s(NN) = 62.4, and 39 GeV, v(2) scales with d N-ch/d eta at midrapidity and forward rapidity, but falls off at backward rapidity. This departure from the d N-ch/d eta scaling may be a further indication of nonflow effects dominating at backward rapidity.
  • Aidala, C.; Kim, D. J.; Krizek, F.; Novitzky, N.; Rak, J.; PHENIX Collaboration (2017)
    We report the first measurement of the fraction of J/psi mesons coming from B-meson decay (F (B -> J/psi)) in p + p collisions at root s = 510 GeV. The measurement is performed using the forward silicon vertex detector and central vertex detector at PHENIX, which provide precise tracking and distance-of-closest-approach determinations, enabling the statistical separation of J=. due to B-meson decays from prompt J/psi. The measured value of F (B -> J/psi) is 8.1% +/- 2.3% (stat) +/- 1.9% (syst) for J/psi with transverse momenta 0 <p(T) <5 GeV/c and rapidity 1.2 <vertical bar y vertical bar <2.2. The measured fraction F (B -> J/psi) at PHENIX is compared to values measured by other experiments at higher center of mass energies and to fixed-order-next-toleading- logarithm and color-evaporation-model predictions. The b (b) over bar cross section per unit rapidity [d sigma/dy(pp -> b (b) over bar)] extracted from the obtained F (B -> J/psi) and the PHENIX inclusive J/psi cross section measured at 200 GeV scaled with color-evaporation-model calculations, at the mean B hadron rapidity y = +/- 1.7 in 510 GeV p + p collisions, is 3.63(-1.70)(+1.92) mu b. It is consistent with the fixed-order-next-toleading- logarithm calculations.
  • PHENIX Collaboration; Aidala, C.; Kim, D. J. (2018)
    Recently, multiparticle-correlation measurements of relativistic p/d(3)He + Au, p + Pb, and even p + p collisions show surprising collective signatures. Here, we present beam-energy-scan measurements of two, four-, and six-particle angular correlations in d + Au collisions at root s(NN) = 200, 62.4, 39, and 19.6 GeV. We also present measurements of two-and four-particle angular correlations in p + Au collisions at root s(NN) = 200 GeV. We find the four-particle cumulant to be real valued for d + Au collisions at all four energies. We also find that the four-particle cumulant in p + Au has the opposite sign as that in d + Au. Further, we find that the six-particle cumulant agrees with the four-particle cumulant in d + Au collisions at 200 GeV, indicating that nonflow effects are subdominant. These observations provide strong evidence that the correlations originate from the initial geometric configuration, which is then translated into the momentum distribution for all particles, commonly referred to as collectivity.
  • PHENIX Collaboration; Aidala, C.; Kim, D. J.; Krizek, F.; Novitzky, N.; Rak, J. (2018)
    Production of pi(0) and eta mesons has been measured at midrapidity in Cu+Au collisions at root S-NN = 200 GeV. Measurements were performed in pi(0) (eta) -> gamma gamma decay channel in the 1(2)-20 GeV/c transverse momentum range. A strong suppression is observed for pi(0) and eta meson production at high transverse momentum in central Cu+Au collisions relative to the p + p results scaled by the number of nucleon-nucleon collisions. In central collisions the suppression is similar to Au + Au with comparable nuclear overlap. The eta/pi(0) ratio measured as a function of transverse momentum is consistent with m(T)-scaling parametrization down to p(T) = 2 GeV/c, its asymptotic value is constant and consistent with Au + Au and p + p and does not show any significant dependence on collision centrality. Similar results were obtained in hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions as well as in e(+)e(-) collisions in a range of collision energies root S-NN = 3-1800 GeV. This suggests that the quark-gluon-plasma medium produced in Cu+Cu collisions either does not affect the jet fragmentation into light mesons or it affects the pi(0) and eta the same way.
  • Sotty, C.; Zielinska, M.; Georgiev, G.; Balabanski, D. L.; Stuchbery, A. E.; Blazhev, A.; Bree, N.; Chevrier, R.; Das Gupta, S.; Daugas, J. M.; Davinson, T.; De Witte, H.; Diriken, J.; Gaffney, L. P.; Geibel, K.; Hadynska-Klek, K.; Kondev, F. G.; Konki, J.; Kroell, T.; Morel, P.; Napiorkowski, P.; Pakarinen, J.; Reiter, P.; Scheck, M.; Seidlitz, M.; Siebeck, B.; Simpson, G.; Toernqvist, H.; Warr, N.; Wenander, F. (2015)
    Excited states of the neutron-rich nuclei Rb-97,Rb- 99 were populated for the first time using the multistep Coulomb excitation of radioactive beams. Comparisons of the results with particle-rotor model calculations provide clear identification for the ground-state rotational band of Rb-97 as being built on the pi g(9/2) [431] 3/2(+) Nilsson-model configuration. The ground-state excitation spectra of the Rb isotopes show a marked distinction between single-particle-like structures below N = 60 and rotational bands above. The present study defines the limits of the deformed region around A similar to 100 and indicates that the deformation of Rb-97 is essentially the same as that observed well inside the deformed region. It further highlights the power of the Coulomb-excitation technique for obtaining spectroscopic information far from stability. The Rb-99 case demonstrates the challenges of studies with very short-lived postaccelerated radioactive beams.
  • CDF Collaboration; Aaltonen, T.; Amerio, S.; Amidei, D.; Brucken, E.; Devoto, F.; Mehtala, P.; Orava, R. (2019)
    We report on a search for a spin-zero non-standard model particle in proton-antiproton collisions collected by the Collider Detector at Fermilab at a center-of-mass-energy of 1.96 TeV. This particle, the phi boson, is expected to decay into a bottom-antibottom quark pair and to be produced in association with at least one bottom quark. The data sample consists of events with three jets identified as initiated by bottom quarks and corresponds to 5.4 fb(-1) of integrated luminosity. In each event, the invariant mass of the two most energetic jets is studied by looking for deviations from the multijet background, which is modeled using data. No evidence is found for such a particle. Exclusion upper limits ranging from 20 to 2 pb are set for the product of production cross sections times branching fraction for the hypothetical phi boson with mass between 100 and 300 GeV/c(2). These are the most stringent constraints to date.
  • Lipiäinen, Tiina; Pessi, Jenni; Movahedi, Parisa; Koivistoinen, Juha; Kurki, Lauri; Tenhunen, Mari; Yliruusi, Jouko; Juppo, Anne M.; Heikkonen, Jukka; Pahikkala, Tapio; Strachan, Clare J. (2018)
    Raman spectroscopy is widely used for quantitative pharmaceutical analysis, but a common obstacle to its use is sample fluorescence masking the Raman signal. Time-gating provides an instrument-based method for rejecting fluorescence through temporal resolution of the spectral signal and allows Raman spectra of fluorescent materials to be obtained. An additional practical advantage is that analysis is possible in ambient lighting. This study assesses the efficacy of time-gated Raman spectroscopy for the quantitative measurement of fluorescent pharmaceuticals. Time-gated Raman spectroscopy with a 128 X (2) X 4 CMOS SPAD detector was applied for quantitative analysis of ternary mixtures of solid-state forms of the model drug, piroxicam (PRX). Partial least-squares (PLS) regression allowed quantification, with Raman-active time domain selection (based on visual inspection) improving performance. Model performance was further improved by using kernel-based regularized least-squares (RLS) regression with greedy feature selection in which the data use in both the Raman shift and time dimensions was statistically optimized. Overall, time-gated Raman spectroscopy, especially with optimized data analysis in both the spectral and time dimensions, shows potential for sensitive and relatively routine quantitative analysis of photoluminescent pharmaceuticals during drug development and manufacturing.