Measurement of forward W → eν production in pp collisions at s=8 TeV

• Published in: The journal of high energy physics 2016-10, Vol.2016 (10)
• Main Authors: Akar, S., Alkhazov, G., Aslanides, E., Batsukh, B., Bertolin, A., Birnkraut, A., Brodzicka, J., Buytaert, J., Cavallero, G., Charles, M., Chatzikonstantinidis, G., Chobanova, V., Clemencic, M., Cliff, H. V., Closier, J., Cogneras, E., Cook, A., Dall’Occo, E., De Aguiar Francisco, O., De Cian, M., De Paula, L., Dettori, F., Dziurda, A., Ely, S., Evans, T., Fontana, M., Gambetta, S., Garcia Martin, L. M., Garra Tico, J., Garrido, L., Graziani, G., Gys, T., Haen, C., Haines, S. C., Hall, S., Henry, L., Hicheur, A., Kandybei, S., Kenyon, I. R., Kenzie, M., Klimaszewski, K., Kozachuk, A., Kozeiha, M., Kravchuk, L., Kreplin, K., Krokovny, P., Krzemien, W., Leflat, A., Lionetto, F., Liu, B., Longstaff, I., Lucchesi, D., Maev, O., Marin Benito, C., Matev, R., Mathad, A., Mogini, A., Mountain, R., Müller, V., Nikitin, N., Oyanguren, A., Palutan, M., Panman, J., Patrignani, C., Penso, G., Pescatore, L., Petridis, K., Petruzzo, M., Pietrzyk, B., Piucci, A., Polci, F., Potterat, C., Puig Navarro, A., Qian, W., Remon Alepuz, C., Renaudin, V., Rodrigues, E., Rogozhnikov, A., Roiser, S., Ronayne, J. W., Saitta, B., Salustino Guimaraes, V., Schubert, K., Schune, M.-H., Sergi, A., Stahl, M., Steinkamp, O., Stoica, S., Tekampe, T., van Tilburg, J., Tully, A., van Veghel, M., Vorobyev, A., Wallace, C., Ward, D. R., Wark, H. M., Wyllie, K., Zheng, Y., Zhokhov, A., Zhu, X.
• Format: Article
• Language: English
• Subjects: Classical and Quantum Gravitation; Elementary Particles; Hadron interactions; Interaccions d'hadrons; Particles (Nuclear physics); Partícules (Física nuclear); Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Regular Article - Experimental Physics; Relativity Theory; String Theory
• ISSN: 1126-6708; 1029-8479
• DOI: 10.1007/JHEP10(2016)030

A bstract A measurement of the cross-section for W → eν production in pp collisions is presented using data corresponding to an integrated luminosity of 2 fb −1 collected by the LHCb experiment at a centre-of-mass energy of s = 8 TeV. The electrons are required to have more than 20 GeV of transverse momentum and to lie between 2 . 00 and 4 . 25 in pseudorapidity. The inclusive W production cross-sections, where the W decays to eν , are measured to be σ W + → e + ν e = 1124.4 ± 2.1 ± 21.5 ± 11.2 ± 13.0 p b , σ W − → e − ν ¯ e = 809.0 ± 1.9 ± 18.1 ± 7.0 ± 9.4 p b , where the first uncertainties are statistical, the second are systematic, the third are due to the knowledge of the LHC beam energy and the fourth are due to the luminosity determination. Differential cross-sections as a function of the electron pseudorapidity are measured. The W + /W − cross-section ratio and production charge asymmetry are also reported. Results are compared with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics. Finally, in a precise test of lepton universality, the ratio of W boson branching fractions is determined to be ℬ W → e ν / ℬ W → μ ν = 1.020 ± 0.002 ± 0.019 , where the first uncertainty is statistical and the second is systematic.