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Title: Resolution to the B{yields}{pi}K puzzle

Abstract

We calculate the important next-to-leading-order contributions to the B{yields}{pi}K, {pi}{pi} decays from the vertex corrections, the quark loops, and the magnetic penguins in the perturbative QCD approach. It is found that the latter two reduce the leading-order penguin amplitudes by about 10% and modify only the B{yields}{pi}K branching ratios. The main effect of the vertex corrections is to increase the small color-suppressed tree amplitude by a factor of 3, which then resolves the large difference between the direct CP asymmetries of the B{sup 0}{yields}{pi}{sup {+-}}K{sup {+-}} and B{sup {+-}}{yields}{pi}{sup 0}K{sup {+-}} modes. The puzzle from the large B{sup 0}{yields}{pi}{sup 0}{pi}{sup 0} branching ratio still remains.

Authors:
 [1];  [2];  [3]
  1. Institute of Physics, Academia Sinica, Taipei, Taiwan 115 (China) and Department of Physics, National Cheng-Kung University, Tainan, Taiwan 701 (China)
  2. Department of Physics, Tohoku University, Sendai 980-8578 (Japan)
  3. Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)
Publication Date:
OSTI Identifier:
20774425
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 72; Journal Issue: 11; Other Information: DOI: 10.1103/PhysRevD.72.114005; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; AMPLITUDES; ASYMMETRY; B MESONS; BRANCHING RATIO; COLOR MODEL; CORRECTIONS; CP INVARIANCE; FEYNMAN DIAGRAM; HADRONIC PARTICLE DECAY; KAONS MINUS; KAONS PLUS; PIONS NEUTRAL; QUANTUM CHROMODYNAMICS; QUARKS; RESOLUTION

Citation Formats

Li Hsiangnan, Mishima, Satoshi, and Sanda, A.I. Resolution to the B{yields}{pi}K puzzle. United States: N. p., 2005. Web. doi:10.1103/PhysRevD.72.114005.
Li Hsiangnan, Mishima, Satoshi, & Sanda, A.I. Resolution to the B{yields}{pi}K puzzle. United States. doi:10.1103/PhysRevD.72.114005.
Li Hsiangnan, Mishima, Satoshi, and Sanda, A.I. Thu . "Resolution to the B{yields}{pi}K puzzle". United States. doi:10.1103/PhysRevD.72.114005.
@article{osti_20774425,
title = {Resolution to the B{yields}{pi}K puzzle},
author = {Li Hsiangnan and Mishima, Satoshi and Sanda, A.I.},
abstractNote = {We calculate the important next-to-leading-order contributions to the B{yields}{pi}K, {pi}{pi} decays from the vertex corrections, the quark loops, and the magnetic penguins in the perturbative QCD approach. It is found that the latter two reduce the leading-order penguin amplitudes by about 10% and modify only the B{yields}{pi}K branching ratios. The main effect of the vertex corrections is to increase the small color-suppressed tree amplitude by a factor of 3, which then resolves the large difference between the direct CP asymmetries of the B{sup 0}{yields}{pi}{sup {+-}}K{sup {+-}} and B{sup {+-}}{yields}{pi}{sup 0}K{sup {+-}} modes. The puzzle from the large B{sup 0}{yields}{pi}{sup 0}{pi}{sup 0} branching ratio still remains.},
doi = {10.1103/PhysRevD.72.114005},
journal = {Physical Review. D, Particles Fields},
number = 11,
volume = 72,
place = {United States},
year = {Thu Dec 01 00:00:00 EST 2005},
month = {Thu Dec 01 00:00:00 EST 2005}
}
  • We study B{yields}K*{rho} modes that are analogues of the much studied B{yields}K{pi} modes with B decaying to two vector mesons instead of pseudoscalar mesons, using topological amplitudes in the quark diagram approach. We show how B{yields}K*{rho} modes can be used to obtain many more observables than those for B{yields}K{pi} modes, even though the quark level subprocesses of both modes are exactly the same. All the theoretical parameters (except for the weak phase {gamma}), such as the magnitudes of the topological amplitudes and their strong phases, can be determined in terms of the observables without any model-dependent assumption. We demonstrate howmore » B{yields}K*{rho} can also be used to verify if there exist any relations between theoretical parameters, such as the hierarchy relations between the topological amplitudes and possible relations between the strong phases. Conversely, if there exist reliable theoretical estimates of amplitudes and strong phases, the presence of new physics could be probed. We show that if the tree and color-suppressed tree are related to the electroweak penguins and color-suppressed electroweak penguins, it is not only possible to verify the validity of such relations but also to have a clean measurement of new physics parameters. We also present a numerical study to examine which of the observables are more sensitive to new physics.« less
  • Branching fraction measurements of charmless B{sup 0}{yields}K*{sup 0}h{sub 1}{sup +}h{sub 2}{sup -} (h{sub 1,2}=K, {pi}) decays are presented, using a data sample of 383x10{sup 6} {upsilon}(4S){yields}BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B-meson factory at SLAC. The results are B(B{sup 0}{yields}K*{sup 0}K{sup +}K{sup -})=(27.5{+-}1.3{+-}2.2)x10{sup -6}, B(B{sup 0}{yields}K*{sup 0}{pi}{sup +}K{sup -})=(4.6{+-}1.1{+-}0.8)x10{sup -6}, and B(B{sup 0}{yields}K*{sup 0}{pi}{sup +}{pi}{sup -})=(54.5{+-}2.9{+-}4.3)x10{sup -6}. The first errors quoted are statistical and the second are systematic. An upper limit is set for B(B{sup 0}{yields}K*{sup 0}K{sup +}{pi}{sup -})<2.2x10{sup -6} at 90% confidence level. We also present measurements of CP-violating asymmetries for the observed decays.
  • The present B{yields}{pi}K data is studied in the context of the standard model (SM) and with new physics (NP). We confirm that the SM has difficulties explaining the B{yields}{pi}K measurements. By adopting an effective-lagrangian parametrization of NP effects, we are able to rule out several classes of NP. Our model-independent analysis shows that the B{yields}{pi}K data can be accommodated by NP in the electroweak penguin sector.
  • In the light of new experimental results on B{yields}K{pi} decays, we critically study the decay processes B{yields}K{pi} in a phenomenological way. Using the quark diagram approach and the currently available data, we determine the allowed values of the relevant theoretical parameters, corresponding to the electroweak (EW) penguin, the color-suppressed tree contribution, etc. In order to find the most likely values of the parameters in a statistically reliable way, we use the {chi}{sup 2} minimization technique. Our result shows that the current data for B{yields}K{pi} decays strongly indicate (large) enhancements of both the EW penguin and the color-suppressed tree contributions. Inmore » particular, the color-suppressed tree effect needs to be enhanced by about an order of magnitude to fit the present data.« less
  • The present B {yields} {pi}K data is studied in the context of the standard model (SM) and with new physics (NP). We confirm that the SM has difficulties explaining the B {yields} {pi}K measurements. By adopting an effective-lagrangian parametrization of NP effects, we are able to rule out several classes of NP. Our model-independent analysis shows that the B {yields} {pi}K data can be accommodated by NP in the electroweak penguin sector.