Measurement of Partial Widths and Search for Direct CP Violation

Authors

Darin Acosta, University of FloridaFollow
Kenneth A. Bloom, University of Nebraska-LincolnFollow
Collider Detector at Fermilab Collaboration

Date of this Version

4-1-2005

Comments

Published by American Physical Society. Phys. Rev. Lett. 94, 122001 (2005). http://prl.aps.org. Copyright © 2005 American Physical Society. Permission to use.

Abstract

We present a measurement of relative partial widths and decay rate CP asymmetries in K^-K⁺ and π^- π⁺ decays of D⁰ mesons produced in pp̅ collisions at √s=1.96 TeV. We use a sample of 2×10⁵ D*+ D⁰ π⁺ (and charge conjugate) decays with the D⁰ decaying to K^- π ⁺, K^-K⁺, and π^- π⁺, corresponding to 123 pb^-1 of data collected by the Collider Detector at Fermilab II experiment at the Fermilab Tevatron collider. No significant direct CP violation is observed. We measure Γ (D⁰→ K^-K⁺)/ Γ (D⁰→ K^- π ⁺)=0.0992±0.0011±0.0012, Γ (D⁰→ π^- π⁺)/ Γ (D⁰→ K^- π ⁺)=0.035 94±0.000 54±0.000 40, ACP(K^-K⁺)=(2.0±1.2±0.6)%, and ACP(π^- π⁺)=(1.0±1.3±0.6)%, where, in all cases, the first uncertainty is statistical and the second is systematic.