Possible large directCPviolations in charmlessBmeson decays: Summary report on the PQCD method

Abstract

We discuss the perturbative QCD approach for the exclusive two body B-meson decays to light mesons. We briefly review its ingredients and some important theoretical issues on factorization approach. We show numerical results which are compatible with present experimantal data for the charmless B-meson decays. Specailly we predict the possibility of large direct CP violation effects in B 0 → π + π − (23 ± 7%) and B 0 → K + π − (−17 ± 5%). In the last section we investigate two methods to determine the weak phases φ 2 and φ 3 from B → ππ, Kπ processes. We obtain bounds on φ 2 and φ 3 from present experimental measurements.Talk given by Y.-Y. Keum at the 3rd workshop on Higher Luminosity B Factory,

Determining weak phases from theB→ππ,Kπdecays

“…(9) is in agreement with the theoretical prediction from the perturbative QCD (PQCD) approach, (0.20 ± 0.04) exp(−156 o i) [4,15]. The extracted P/T in Eq.…”

CP Violation Studies at Tevatron

“…B-factories recently measured a O(10%) asymmetry with 2% accuracy, probing for the first time direct CP violation in the b-quark sector [4,5]; however, additional experimental information is needed because theoretical predictions still suffer from large (5-10%) uncertainties [6,7,8], and the observed asymmetries in neutral and charged modes are not consistent, as the SM would suggest. A measurement from the Tevatron is therefore interesting, also for the unique possibility to combine asymmetry measurements in B 0 → K + π − and B 0 s → K − π + decays, which provide a model-independent probe for the presence of non-SM physics [9].…”

“…A CP (B 0 → K + π − ) = (−5.8 ± 3.9 ± 0.7)%, (6) which is approximately 1.5σ different from zero, and in agreement with world best results: A CP (B 0 → K + π − ) = (−10.8 ± 2.4 ± 0.7)%= from the Babar Collaboration [4] and A CP (B 0 → K + π − ) = (−9.3±1.8±0.8)%, from the Belle Collaboration [5].…”

Search for TeV scale physics in heavy flavor decays

“…This was done in the PQCD approach up to next-to-leading order (NLO), which is the state of the art. We note that PQCD is the only QCD-based factorization approach that predicted [29] both the strength and …”