@article{10902/2260,
year = {2012},
month = {1},
url = {http://hdl.handle.net/10902/2260},
abstract = {We present a search for new phenomena in events with two reconstructed Z bosons and large missing transverse momentum, sensitive to processes pp̅ →X2X2→ZZX1X1, where X2 is an unstable particle decaying as X2→ZX1 and X1 is undetected. The particles X1 and X2 may be, among other possibilities, fourth-generation neutrinos or supersymmetric particles. We study the final state in which one Z boson decays to two charged leptons and the second decays hadronically. In data corresponding to an integrated luminosity of 4.2  fb-1 from proton-antiproton collisions recorded by the CDF II detector at the Tevatron, with center-of-mass energy of 1.96 TeV, we find agreement between data and standard-model backgrounds. We calculate 95% confidence level upper limits on the cross section of the process pp̅ →X2X2→ZZX1X1 ranging from 50 fb to 1 pb, depending on the masses of X1 and X2.},
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 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. D, Particles, fields, gravitation, and cosmology, 2012, 85(1), 011104(R)},
title = {Search for new phenomena in events with two Z bosons and missing transverse momentum in pp̅ collisions at √s=1.96  TeV},
author = {Aaltonen, Timo Antero and Amerio, Silvia and Amidei, Dante and Anastassov, Anton and Annovi, Alberto and Antos, Jaroslav and Apollinari, Giorgio and Appel, Jeffrey A. 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 and Arisawa, Tetsuo and Álvarez González, Bárbara},
}