Record |
Author |
BABAR and Belle Collaborations (Adachi, I.. et al); Martinez-Vidal, F.; Oyanguren, A. |
Title |
First Evidence for cos 2 beta > 0 and Resolution of the Cabibbo-Kobayashi-Maskawa Quark-Mixing Unitarity Triangle Ambiguity |
Type |
Journal Article |
Year |
2018 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
121 |
Issue |
26 |
Pages |
261801 - 11pp |
Keywords |
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Abstract |
We present first evidence that the cosine of the CP-violating weak phase 2 beta is positive, and hence exclude trigonometric multifold solutions of the Cabibbo-Kobayashi-Maskawa (CKM) Unitarity Triangle using a time-dependent Dalitz plot analysis of B-0 -> D-(*) h(0) with D -> K-S(0)pi(+)pi(-) decays, where h(0) is an element of {pi(0), eta, omega} denotes a light unflavored and neutral hadron. The measurement is performed combining the final data sets of the BABAR and Belle experiments collected at the (sic)(4S) resonance at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain (471 +/- 3) x 10(6) B (B) over bar pairs recorded by the BABAR detector and (772 +/- 11) x 10(6) B (B) over bar pairs recorded by the Belle detector. The results of the measurement are sin 2 beta = 0.80 +/- 0.14 (stat) +/- 0.06 (syst) +/- 0.03 (model) and cos 2 beta = 0.91 +/- 0.22(stat) +/- 0.09 (syst) +/- 0.07(model). The result for the direct measurement of the angle beta of the CKM Unitarity Triangle is beta = [22.5 +/- 4.4 (stat) +/- 1.2 (syst) +/- 0.6(model)]degrees. The measurement assumes no direct CP violation in B-0 -> D-(*) h(0) decays. The quoted model uncertainties are due to the composition of the D-0 -> K-S(0)pi(+)pi(-) decay amplitude model, which is newly established by performing a Dalitz plot amplitude analysis using a high-statistics e(+)e(-) -> c (c) over bar data sample. CP violation is observed in B-0 -> D-(*) h(0) decays at the level of 5.1 standard deviations. The significance for cos 2 beta > 0 is 3.7 standard deviations. The trigonometric multifold solution pi/2 – beta = (68.1 +/- 0.7)degrees is excluded at the level of 7.3 standard deviations. The measurement resolves an ambiguity in the determination of the apex of the CKM Unitarity Triangle. |
Address |
[Lees, J. P.; Poireau, V.; Tisserand, V.] Univ Savoie, CNRS IN2P3, LAPP, F-74941 Annecy Le Vieux, France |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0031-9007 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000454432900004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3858 |
Permanent link to this record |