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Reis, T.

Publications and source records attributed to Reis, T..

At least 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Measurement of prompt ψ ( 2 S ) to J / ψ yield ratios in Pb-Pb and p - p collisions at s N N = 2.76 TeV

The ratio between the prompt ψ(2S) and J/ψ yields, reconstructed via their decays into μ⁺μ⁻, is measured in Pb-Pb and p-p collisions at √ s NN = 2.76 TeV. The analysis is based on Pb-Pb and p-p data samples collected by CMS at the Large Hadron Collider, corresponding to integrated luminosities of 150 μb⁻¹ and 5.4 pb⁻¹, respectively. The double ratio of measured yields (N ψ(2S) /N J/ψ ) Pb−Pb /(N ψ(2S) /N J/ψ ) p−p is computed in three Pb-Pb collision centrality bins and two kinematic ranges: one at midrapidity, |y| < 1.6, covering the transverse momentum range 6.5 < p T < 30 GeV/c, and the other at forward rapidity, 1.6<|y|<2.4, extending to lower pT values, 3<pT<30 GeV/c. The centrality-integrated double ratio changes from 0.45 ± 0.13 (stat) ± 0.07 (syst) in the first range to 1.67 ± 0.34 (stat) ± 0.27 (syst) in the second. This difference is most pronounced in the most central collisions.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2014

Measurement of the ratio of inclusive jet cross sections using the anti- k T algorithm with radius parameters R = 0.5 and 0.7 in p p collisions at s = 7 TeV

Measurements of the inclusive jet cross section with the anti-k T clustering algorithm are presented for two radius parameters, R = 0.5 and 0.7. They are based on data from LHC proton-proton collisions at √s = 7 TeV corresponding to an integrated luminosity of 5.0 fb⁻¹ collected with the CMS detector in 2011. The ratio of these two measurements is obtained as a function of the rapidity and transverse momentum of the jets. Significant discrepancies are found comparing the data to leading-order simulations and to fixed-order calculations at next-to-leading order, corrected for nonperturbative effects, whereas simulations with next-to-leading-order matrix elements matched to parton showers describe the data best.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗