A Measurement of the Prompt J/Psi Spin Alignment in CDF Run II Data

A Measurement of the Prompt J/ψ Spin Alignment in CDF Run II Data

We present a measurement of the spin alignment of promptly-produced J/ψ mesons having 5 ≤ p_T < 30 GeV and rapidity |y| < 0.6. Only J/ψ decays to &mu⁺ &mu^- pairs with muon p_T > 1.75 GeV were used in this analysis, to match well with the GEANT-based CDF detector simulation. Promptly-produced events were distinguished from J/ψ mesons from heavy flavor decays by impact parameter requirements on the two muons. The data contains 151,553 J/ψ mesons with signal/background ratio of 13.9, taken with the Run II CMU Dimuon Triggers. The integrated luminosity was 188± 11 pb^-1. The analysis uses the same fitting methodology developed for the CDF Run I measurement.

Description

A complete description of the analysis is available here: ps.
Blessed: April 28, 2005
Data: Run II, 188+-11 pb^-1

Blessed Plots

Prompt J/ψ Polarization:
	EPS