@article{10902/2147, year = {2011}, month = {11}, url = {http://hdl.handle.net/10902/2147}, abstract = {We present a search for a new particle T′ decaying to a top quark via T′→t+X, where X goes undetected. We use a data sample corresponding to 5.7  fb-1 of integrated luminosity of pp̅ collisions with √s=1.96  TeV, collected at Fermilab Tevatron by the CDF II detector. Our search for pair production of T′ is focused on the hadronic decay channel, pp̅ →T′T̅ ′→tt̅ +XX̅ →bqq̅ b̅ qq̅ +XX̅ . We interpret our results in terms of a model where T′ is an exotic fourth generation quark and X is a dark matter particle. The data are consistent with standard model expectations. We set a limit on the generic production of T′T̅ ′→tt̅ +XX̅ , excluding the fourth generation exotic quarks T′ at 95% confidence level up to mT′=400  GeV/c2 for mX≤70  GeV/c2.}, organization = {We thank Johan Alwall and Matteo Cacciari for useful discussions. We also 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 and the Royal Society, UK; the Institut National de Physique Nucleaire et Physique des Particules/CNRS; 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, 2011, 107(19), 191803}, title = {Search for new T′ particles in final states with large jet multiplicities and missing transverse energy in pp̅ collisions at √s=1.96  TeV}, author = {Aaltonen, Timo Antero and Álvarez González, Bárbara and Casal Laraña, Bruno and Cuevas Maestro, Francisco Javier and Gómez Gramuglio, Gervasio and Palencia Cortezón, José Enrique and Rodrigo Anoro, Teresa and Ruiz Jimeno, Alberto and Scodellaro, Luca and Vila Álvarez, Iván and Vilar Cortabitarte, Rocío and Vizán García, Jesús Manuel}, }