@article{10902/28869, year = {2013}, url = {https://hdl.handle.net/10902/28869}, abstract = {The first observation of the production of a W boson with a single charm quark (c) jet in p¯p collisions at √s=1.96  TeV is reported. The analysis uses data corresponding to 4.3  fb−1, recorded with the CDF II detector at the Fermilab Tevatron. Charm quark candidates are selected through the identification of an electron or muon from charm-hadron semileptonic decay within a hadronic jet, and a Wc signal is observed with a significance of 5.7 standard deviations. The production cross section σWc(pTc>20  GeV/c,|ηc|<1.5)×B(W→ℓν) is measured to be 13.6+3.4−3.1  pb and is in agreement with theoretical expectations. From this result the magnitude of the quark-mixing matrix element Vcs is derived, |Vcs|=1.08±0.16 along with a lower limit of |Vcs|>0.71 at the 95% confidence level, assuming that the Wc production through c to s quark coupling is dominant.}, organization = {We thank the Fermilab staff and the technical staffs of the participating institutions for their vital contributions. This work was supported by the U.S. Department of Energy and National Science Foundation; the Italian Istituto Nazionale di Fisica Nucleare; the Ministry of Education, Culture, Sports, Science and Technology of Japan; the Natural Sciences and Engineering Research Council of Canada; the National Science Council of the Republic of China; the Swiss National Science Foundation; the A. P. Sloan Foundation; the Bundesministerium für Bildung und Forschung, Germany; the Korean World Class University Program, the National Research Foundation of Korea; the Science and Technology Facilities Council, the Royal Society and the Leverhulme Trust, U.K.; the Russian Foundation for Basic Research; the Ministerio de Ciencia e Innovación, and Programa Consolider-Ingenio 2010, Spain; the Slovak R&D Agency; the Academy of Finland; and the Australian Research Council (ARC).}, publisher = {American Physical Society}, publisher = {Physical Review Letters 2013, 110(7), 071801}, title = {Observation of the production of a W boson in association with a single charm quark}, author = {Aaltonen, Timo Antero and Casal Laraña, Bruno and Cuevas Maestro, Francisco Javier and Gómez Gramuglio, Gervasio and Palencia Cortezón, José Enrique and Ruiz Jimeno, Alberto and Scodellaro, Luca and Vilar Cortabitarte, Rocío and Vizán García, Jesús Manuel}, }