Search for production of an Upsilon(1S) meson in association with a W or Z boson using the full 1.96 TeV proton anti-proton collision data set at CDF

TL;DR

This study searches for rare Upsilon(1S) meson production with W or Z bosons in proton-antiproton collisions, using the full CDF II dataset, to test standard model predictions and explore potential new physics.

Contribution

First comprehensive search for Upsilon(1S)+W/Z production at Tevatron, setting the most sensitive upper limits and constraining non-standard-model contributions.

Findings

Observed one Upsilon(1S)W candidate with background of 1.2 +/- 0.5 events.

Observed one Upsilon(1S)Z candidate with background of 0.1 +/- 0.1 events.

Results are consistent with standard model background predictions.

Abstract

Production of the Upsilon(1S) meson in association with a vector boson is a rare process in the standard model with a cross section predicted to be below the sensitivity of the Tevatron. Observation of this process could signify contributions not described by the standard model or reveal limitations with the current non-relativistic quantum-chromodynamic models used to calculate the cross section. We perform a search for this process using the full Run II data set collected by the CDF II detector corresponding to an integrated luminosity of 9.4/fb. The search considers the Upsilon(1S) to di-muon decay and the decay of the W and Z bosons into muons and electrons. In these purely leptonic decay channels, we observe one Upsilon(1S)W candidate with an expected background of 1.2 +/- 0.5 events, and one Upsilon(1S)Z candidate with an expected background of 0.1 +/- 0.1 events. Both observations are consistent with the predicted background contributions. The resulting upper limits on the cross section for Upsilon(1S)+W/Z production are the most sensitive reported from a single experiment and place restrictions on potential contributions from non-standard-model physics.