@article{10902/1856,
year = {2011},
month = {5},
url = {http://hdl.handle.net/10902/1856},
abstract = {We present a search for a new particle T′ decaying to top quark via T′→t+X, where X is an invisible particle. In a data sample with 4.8  fb-1 of integrated luminosity collected by the CDF II detector at Fermilab in pp̅ collisions with √s=1.96  TeV, we search for pair production of T′ in the lepton+jets channel, pp̅ →tt̅ +X+X→ℓνbqq′b+X+X. We interpret our results primarily in terms of a model where T′ are exotic fourth generation quarks and X are dark matter particles. Current direct and indirect bounds on such exotic quarks restrict their masses to be between 300 and 600  GeV/c2, the dark matter particle mass being anywhere below mT′. The data are consistent with standard model expectations, and we set 95% confidence level limits on the generic production of T′T̅ ′→tt̅ +X+X. For the dark matter model we exclude T′ at 95% confidence level up to mT′=360  GeV/c2 for mX≤100  GeV/c2.},
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 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; and the Academy of Finland.},
publisher = {American Physical Society},
publisher = {Physical Review Letters, 2011, 106(19), 191801},
title = {Search for production of heavy particles decaying to top quarks and invisible particles 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},
}