A consistent picture for large penguins in D →π+π−, K+K

A bstract A long-standing puzzle in charm physics is the large difference between the D 0 → K + K − and D 0 → π + π − decay rates. Recently, the LHCb and CDF collaborations reported a surprisingly large difference between the direct CP asymmetries, Δ A CP , in these two modes. We show that the two p...

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Bibliographic Details
Published in:The journal of high energy physics 2012-10, Vol.2012 (10), Article 161
Main Authors: Brod, Joachim, Grossman, Yuval, Kagan, Alexander L., Zupan, Jure
Format: Article
Language:English
Subjects:
Asymmetry
Charm (particle physics)
Classical and Quantum Gravitation
Decay rate
Elementary Particles
High energy physics
Physics
Physics and Astronomy
Quantum Field Theories
Quantum Field Theory
Quantum Physics
Quarks
Relativity Theory
String Theory
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Summary:A bstract A long-standing puzzle in charm physics is the large difference between the D 0 → K + K − and D 0 → π + π − decay rates. Recently, the LHCb and CDF collaborations reported a surprisingly large difference between the direct CP asymmetries, Δ A CP , in these two modes. We show that the two puzzles are naturally related in the Standard Model via s - and d -quark “penguin contractions”. Their sum gives rise to Δ A CP , while their difference contributes to the two branching ratios with opposite sign. Assuming nominal SU(3) breaking, we perform a U-spin based fit to the D 0 → K + π − , π + K − , π + π − , K + K − decay rates, which yields large penguin contractions that naturally explain Δ A CP . Expectations for the individual CP asymmetries are also discussed.
ISSN:1029-8479
1029-8479
DOI:10.1007/JHEP10(2012)161