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 p (p) over bar collisions with root s = 1.96 TeV, we search for pair production of T' in the lepton + jets channel, p (p) over bar -> t (t) over bar + X + X -> lnubqq'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/c(2), the dark matter particle mass being anywhere below m(T'). The data are consistent with standard model expectations, and we set 95% confidence level limits on the generic production of T'(T) over bar -> t (t) over bar + X + X. For the dark matter model we exclude T' at 95% confidence level up to m(T)' = 360 GeV/c(2) for m(X) <= 100 GeV/c(2).

Search for Production of Heavy Particles Decaying to Top Quarks and Invisible Particles in p(p)over-bar Collisions at root s=1.96 TeV

CIOCCI, MARIA AGNESE;DONATI, SIMONE;F. Ruffini;
2011-01-01

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 p (p) over bar collisions with root s = 1.96 TeV, we search for pair production of T' in the lepton + jets channel, p (p) over bar -> t (t) over bar + X + X -> lnubqq'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/c(2), the dark matter particle mass being anywhere below m(T'). The data are consistent with standard model expectations, and we set 95% confidence level limits on the generic production of T'(T) over bar -> t (t) over bar + X + X. For the dark matter model we exclude T' at 95% confidence level up to m(T)' = 360 GeV/c(2) for m(X) <= 100 GeV/c(2).
2011
T., Aaltonen; B., Álvarez González; S., Amerio; D., Amidei; A., Anastassov; A., Annovi; J., Antos; G., Apollinari; J., Appel; A., Apresyan; T., Arisaw...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/828833
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