Measurement of the production of a W boson in association with a charm quark in pp collisions at sqrts = 7 TeV with the ATLAS detector

The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at ps = 7TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio ơ(W++c)/ơ(W−+c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s–s quark asymmetry.

Measurement of the production cross section of prompt J/ψ mesons in association with a W± boson in pp collisions at √8 = 7 TeV with the ATLAS detector

The process pp ! W±J/ provides a powerful probe of the production mechanism of charmonium in hadronic collisions, and is also sensitive to multiple parton interactions in the colliding protons. Using the 2011 ATLAS dataset of 4.5 fb−1 of p s =7TeV pp collisions at the LHC, the first observation is made of the production of W± +prompt J/ events in hadronic collisions, using W± → μѵμ and Jψ → μ+μ−. A yield of 27.4+7.5−6.5 W± + prompt J/ψ events is observed, with a statistical significance of 5.1ơ. The production rate as a ratio to the inclusive W± boson production rate is measured, and the double parton scattering contribution to the cross section is estimated.

Peter der Große, ertrinkende Matrosen rettend [Illustration]

Leopold Bernard Bernstamm

Peter der Große als Zimmermann in Zaardam [Illustration]

Leopold Bernard Bernstamm

Peter Benoît, Kniestück

Signatur des Originals: S 36/F00136

Peter Cornelius, Brustbild

Signatur des Originals: S 36/F00296

Peter Josef von Lindpaintner, Brustbild

Signatur des Originals: S 36/F01118

Peter Franz Reichensperger, Brustbild

Signatur des Originals: S 36/F01593

Peter Benoît, Brustbild, Profil, 1894

Signatur des Originals: S 36/F02978

Peter Benoît, Brustbild, 1890

Signatur des Originals: S 36/F02979

Peter Benoît, Brustbild, 1890

Signatur des Originals: S 36/F02980

Geboortehuis van Peter Benoit (1834-1901) te Harelbeke (Westvlaanderen)

Signatur des Originals: S 36/F02981

Geboortehuis van Peter Benoit (1834-1901) te Harelbeke (Westvlaanderen)

Signatur des Originals: S 36/F02982

Begrafenisplechtigheid Van Peter Benoit, Te Antwerpen, 11 Maart 1901, Het Lijk Wordt Uit De Hoofdkerk Gedragen

Signatur des Originals: S 36/F02983

Begrafenisplechtigheid Van Peter Benoit, Te Antwerpen, 11 Maart 1901, Het Lijk Wordt Uit De Hoofdkerk Gedragen

Signatur des Originals: S 36/F02984