Search for new phenomena in events with two Z bosons and missing transverse momentum in p(p)over-bar collisions at root s=1.96 TeV

0382478 - FZÚ 2013 RIV US eng J - Journal Article
Aaltonen, T. - Gonzalez, B.A. - Amerio, S. - Lysák, Roman … Total 475 authors
Search for new phenomena in events with two Z bosons and missing transverse momentum in p(p)over-bar collisions at root s=1.96 TeV.
Physical Review D: Particles, Fields, Gravitation and Cosmology. Roč. 85, č. 1 (2012), "011104-1"-"011104-7". ISSN 1550-7998
R&D Projects: GA MŠMT LC527
Institutional research plan: CEZ:AV0Z10100502
Keywords : Z0 pair production * transverse momentum missing-energy * neutrino * anti-p p scattering * CDF * Batavia TEVATRON Coll
Subject RIV: BF - Elementary Particles and High Energy Physics
Impact factor: 4.691, year: 2012

We present a search for new phenomena in events with two reconstructed $Z$ bosons and large missing transverse momentum, sensitive to processes $p/bar{p}/rightarrow X_2X_2 /rightarrow Z Z X_1 X_1$, where $X_2$ is an unstable particle decaying as $X_2/rightarrow ZX_1$ and $X_1$ is undetected. The particles $X_1$ and $X_2$ 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 $p/bar{p}/rightarrow X_2X_2 /rightarrow Z Z X_1 X_1$ ranging from 50 fb to 1 pb, depending on the masses of $X_1$ and $X_2$.
Permanent Link: http://hdl.handle.net/11104/0212687