Measurement of CP--violating asymmetries in $$D^0\to\pi^+\pi^-$$ and $$D^0\to K^+K^-$$ decays at CDF

Journal Article · Tue Nov 01 04:00:00 EDT 2011 · Phys.Rev.D85:012009,2012

DOI:https://doi.org/10.1103/PhysRevD.85.012009· OSTI ID:1030749

Aaltonen, T; Alvarez Gonzalez, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Arisawa, T; Artikov, A

We report on a measurement of CP-violating asymmetries (A{sub CP}) in the Cabibbo-suppressed D{sup 0} {yields} {pi}{sup +}{pi}{sup -} and D{sup 0} {yields} K{sup +}K{sup -} decays reconstructed in a data sample corresponding to 5.9 fb{sup -1} of integrated luminosity collected by the upgraded Collider Detector at Fermilab. We use the strong decay D*{sup +} {yields} D{sup 0}{pi}{sup +} to identify the flavor of the charmed meson at production and exploit CP-conserving strong c{bar c} pair-production in p{bar p} collisions. High-statistics samples of Cabibbo-favored D{sup 0} {yields} K{sup -}{pi}{sup +} decays with and without a D*{sup {+-}} tag are used to correct for instrumental effects and significantly reduce systematic uncertainties. We measure A{sub CP}(D{sup 0} {yields} {pi}{sup +}{pi}{sup -}) = (+0.22 {+-} 0.24(stat) {+-} 0.11 (syst))% and A{sub CP}(D{sup 0} {yields} K{sup +}K{sup -}) = (-0.24 {+-} 0.22 (stat) {+-} 0.09 (syst))%, in agreement with CP conservation. These are the most precise determinations from a single experiment to date. Under the assumption of negligible direct CP violation in D{sup 0} {yields} {pi}{sup +}{pi}{sup -} and D{sup 0} {yields} K{sup +}K{sup -} decays, the results provide an upper limit to the CP-violating asymmetry in D{sup 0} mixing, |A{sub CP}{sup ind}(D{sup 0})| < 0.13% at the 90% confidence level.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL
• Sponsoring Organization: DOE Office of Science
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 1030749
• Report Number(s): FERMILAB-PUB-11-624-PPD; arXiv eprint number arXiv:1111.5023
• Journal Information: Phys.Rev.D85:012009,2012, Journal Name: Phys.Rev.D85:012009,2012
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMMETRY
CHARMED MESONS
DECAY
Experiment-HEP
Phenomenology-HEP
FERMILAB COLLIDER DETECTOR
LUMINOSITY
PAIR PRODUCTION
PRODUCTION