Using Z gamma candidate events collected by the CDF detector at the Tevatron Collider, we search for potential anomalous (non-standard-model) couplings between the Z boson and the photon. Z gamma couplings vanish at tree level and are heavily suppressed at higher orders; hence any evidence of couplings indicates new physics. Measurements are performed using data corresponding to an integrated luminosity of 4.9 fb(-1) in the Z -> nu(nu) over bar decay channel and 5.1 fb(-1) in the Z -> l(+)l(-) (l=mu, e) decay channels. The combination of these measurements provides the most stringent limits to date on Z gamma trilinear gauge couplings. Using an energy scale of Lambda = 1.5 TeV to allow for a direct comparison with previous measurements, we find limits on the CP-conserving parameters that describe Z gamma couplings to be |h(3)(gamma,Z)| < 0.022 and |h(4)(gamma,Z)| < 0.0009. These results are consistent with standard model predictions.

Limits on Anomalous Trilinear Gauge Couplings in Z gamma Events from p(p)over-bar Collisions at root s=1.96 TeV

CIOCCI, MARIA AGNESE;DONATI, SIMONE;
2011-01-01

Abstract

Using Z gamma candidate events collected by the CDF detector at the Tevatron Collider, we search for potential anomalous (non-standard-model) couplings between the Z boson and the photon. Z gamma couplings vanish at tree level and are heavily suppressed at higher orders; hence any evidence of couplings indicates new physics. Measurements are performed using data corresponding to an integrated luminosity of 4.9 fb(-1) in the Z -> nu(nu) over bar decay channel and 5.1 fb(-1) in the Z -> l(+)l(-) (l=mu, e) decay channels. The combination of these measurements provides the most stringent limits to date on Z gamma trilinear gauge couplings. Using an energy scale of Lambda = 1.5 TeV to allow for a direct comparison with previous measurements, we find limits on the CP-conserving parameters that describe Z gamma couplings to be |h(3)(gamma,Z)| < 0.022 and |h(4)(gamma,Z)| < 0.0009. These results are consistent with standard model predictions.
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/11568/828611
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