9 research outputs found

    Two- and three-pion quantum statistics correlations in Pb-Pb collisions at root S-NN=2.76 TeV at the CERN Large Hadron Collider

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    Correlations induced by quantum statistics are sensitive to the spatiotemporal extent as well as dynamics of particle-emitting sources in heavy-ion collisions. In addition, such correlations can be used to search for the presence of a coherent component of pion production. Two- and three-pion correlations of same and mixed charge are measured at low relative momentum to estimate the coherent fraction of charged pions in Pb-Pb collisions at root S-NN = 2.76 TeV at the CERN Large Hadron Collider with ALICE. The genuine three-pion quantum statistics correlation is found to be suppressed relative to the two-pion correlation based on the assumption of fully chaotic pion emission. The suppression is observed to decrease with triplet momentum. The observed suppression at low triplet momentum may correspond to a coherent fraction in charged-pion emission of 23% +/- 8%

    Two-and three-pion quantum statistics correlations in Pb-Pb collisions at root S-NN=2.76 TeV at the CERN Large Hadron Collider

    No full text
    Correlations induced by quantum statistics are sensitive to the spatiotemporal extent as well as dynamics of particle-emitting sources in heavy-ion collisions. In addition, such correlations can be used to search for the presence of a coherent component of pion production. Two- and three-pion correlations of same and mixed charge are measured at low relative momentum to estimate the coherent fraction of charged pions in Pb-Pb collisions at root S-NN = 2.76 TeV at the CERN Large Hadron Collider with ALICE. The genuine three-pion quantum statistics correlation is found to be suppressed relative to the two-pion correlation based on the assumption of fully chaotic pion emission. The suppression is observed to decrease with triplet momentum. The observed suppression at low triplet momentum may correspond to a coherent fraction in charged-pion emission of 23% +/- 8%

    Measurement of charged jet suppression in Pb-Pb collisions at root s(NN)=2.76 TeV

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    20143NSFC; National Natural Science Foundation of China; Helmholtz Associatio

    Calibration of the photon spectrometer PHOS of the ALICE experiment

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    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 s=13 TeV. After applying all corrections, the achieved mass resolutions for \u3c00 and \u3b7 mesons for pT > 1.7 GeV/c are \u3c3m\u3c0javax.xml.bind.JAXBElement@533d1c3d = 4.56 \ub1 0.03 MeV/c2 and \u3c3m\u3b7 = 15.3 \ub1 1.0 MeV/c2, respectively

    Energy dependence of exclusive J/ photoproduction off protons in ultra-peripheral p-Pb collisions at NN=5.02 TeV

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    The ALICE Collaboration has measured the energy dependence of exclusive photoproduction of J / \u3c8 vector mesons off proton targets in ultra\u2013peripheral p\u2013Pb collisions at a centre-of-mass energy per nucleon pair sNN=5.02 TeV. The e + e - and \u3bc + \u3bc - decay channels are used to measure the cross section as a function of the rapidity of the J / \u3c8 in the range - 2.5 < y< 2.7 , corresponding to an energy in the \u3b3p centre-of-mass in the interval 40 < W \u3b3p < 550 GeV. The measurements, which are consistent with a power law dependence of the exclusive J / \u3c8 photoproduction cross section, are compared to previous results from HERA and the LHC and to several theoretical models. They are found to be compatible with previous measurements

    Charged-particle pseudorapidity density at mid-rapidity in p-Pb collisions at root S-NN=8.16 TeV

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    The pseudorapidity density of charged particles, d N ch / d \u3b7, in p\u2013Pb collisions has been measured at a centre-of-mass energy per nucleon\u2013nucleon pair of 1asNN = 8.16 TeV at mid-pseudorapidity for non-single-diffractive events. The results cover 3.6 units of pseudorapidity, | \u3b7| < 1.8. The d N ch / d \u3b7 value is 19.1 \ub1 0.7 at | \u3b7| < 0.5. This quantity divided by \u27e8 N part \u27e9 / 2 is 4.73 \ub1 0.20 , where \u27e8 N part \u27e9 is the average number of participating nucleons, is 9.5% higher than the corresponding value for p\u2013Pb collisions at 1asNN = 5.02 TeV. Measurements are compared with models based on different mechanisms for particle production. All models agree within uncertainties with data in the Pb-going side, while HIJING overestimates, showing a symmetric behaviour, and EPOS underestimates the p-going side of the d N ch / d \u3b7 distribution. Saturation-based models reproduce the distributions well for \u3b7> - 1.3. The d N ch / d \u3b7 is also measured for different centrality estimators, based both on the charged-particle multiplicity and on the energy deposited in the Zero-Degree Calorimeters. A study of the implications of the large multiplicity fluctuations due to the small number of participants for systems like p\u2013Pb in the centrality calculation for multiplicity-based estimators is discussed, demonstrating the advantages of determining the centrality with energy deposited near beam rapidity

    Dietary Polyphenols and Mitochondrial Function: Role in Health and Disease

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