Evidence for Direct CP Violation in B-+/- -> eta h(+/-) and Observation of B-0 -> eta K-0

We report measurements of the branching fractions and CP asymmetries for B-+/- -> eta h(+/-) (h = K or pi) and the observation of the decay B-0 -> eta K-0 from the final data sample of 772 x 10(6) B (B) over bar pairs collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The measured branching fractions are B(B-+/- -> eta K-+/-) = (2.12 +/- 0.23 +/- 0.11) x 10(-6), B(B-+/- -> eta pi(+/-)) = (4.07 +/- 0.26 +/- 0.21) x 10(-6), and B(B-0 -> eta K-0) = (1.27(-0.29)(+0.33) +/- 0.08) x 10(-6), where the last decay is observed for the first time with a significance of 5.4 standard deviations (sigma). We also find evidence for CP violation in the charged B modes, A(CP)(B-+/- -> eta K-+/-) = -0.38 +/- 0.11 +/- 0.01 and A(CP)(B-+/- -> eta pi(+/-)) = -0.19 +/- 0.06 +/- 0.01 with significances of 3.8 sigma and 3.0 sigma, respectively. For all measurements, the first and second uncertainties are statistical and systematic, respectively.

À propos de ce résultat

Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.

Concepts associés

Chargement

Publications associées

Chargement

Tagir Aushev, Ji Hyun Kim, Jing Li, Zhen Liu, Remi Léandre Albert Louvot, Olivier Schneider, Mingkui Wang
2012
Article

Résumé

Official source

https://infoscience.epfl.ch/record/175303?ln=fr

À propos de ce résultat

Concepts associés (12)

Concepts associés

Chargement

Publications associées (103)

Publications associées

Chargement

Rapport de branchement

En physique des particules et en physique nucléaire, le rapport de branchement (ou rapport d'embranchement) désigne la probabilité de voir un nucléide emprunter un mode de désintégration radioactive d

Violation de CP

En physique des particules, la violation de CP est une violation de la symétrie CP, c'est-à-dire de la combinaison de la symétrie C (symétrie de conjugaison de charge) et de la symétrie P (symétrie de

Mesure physique

La mesure physique est l'action de déterminer la ou les valeurs d'une grandeur (longueur, capacité), par comparaison avec une grandeur constante de même espèce prise comme terme de référence (étalon

Observation of D+ -> K+eta(()'()) and Search for CP Violation in D+ -> pi(+)eta(()'()) Decays

Tagir Aushev, Aurelio Bay, Sun Hee Kim, Ji Hyun Kim, Jing Li, Yiming Li, Remi Léandre Albert Louvot, Olivier Schneider, Mingkui Wang

We report the first observation of the doubly Cabibbo-suppressed decays D+ -> K+eta(()'()) using a 791 fb(-1) data sample collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The ratio of the branching fractions of doubly Cabibbo-suppressed relative to singly Cabibbo-suppressed D+ -> pi(+)eta(()'()) decays are B(D+ -> K+eta) / B(D+ -> pi(+)eta) =(3.06 +/- 0.43 +/- 0.14)% and B(D+ -> K+eta')/B(D+->pi(+)eta') = (3.77 +/- 0.39 +/- 0.10)%. From these, we find that the relative final-state phase difference between the tree and annihilation amplitudes in D+ decays, delta(TA), is (72 +/- 9)degrees or (288 +/- 9)degrees. We also report the most precise measurements of CP asymmetries to date: A(CP)(D+->pi+eta) = (+1.74 +/- 1.13 +/- 0.19)% and A(CP)(D+->pi+eta') = (-0.12 +/- 1.12 +/- 0.17)%.

2011

Chargement

Measurement of CP asymmetries in B0→K0π0 decays

Tagir Aushev, Vladislav Balagura, Sun Hee Kim, Jing Li, Remi Léandre Albert Louvot, Olivier Schneider

We report measurements of CP violation parameters in B0→K0π0 decays based on a data sample of 657×106BB̄ pairs collected with the Belle detector at the KEKB e+e- asymmetric-energy collider. We use B0→KS0π0 decays for both mixing-induced and direct CP violating asymmetry measurements and B0→KL0π0 decays for the direct CP violation measurement. The CP violation parameters obtained are sin 2 1eff=+0.67±0. 31(stat)±0.08(syst) and AK0π0=+0.14±0.13(stat)±0. 06(syst). The branching fraction of B0→K0π0 decay is measured to be B(B0→K0π0)=(8.7±0.5(stat.)±0.6(syst.))×10 -6. The observed AK0π0 value differs by 1.9 standard deviations from the value expected from an isospin sum rule. © 2010 The American Physical Society.

2010

Chargement

Measurement of branching fraction and first evidence of CP violation in B-0 -> a(1)(+/-)(1260)pi(-/+) decays

Tagir Aushev, Aurelio Bay, Ji Hyun Kim, Jing Li, Zhen Liu, Remi Léandre Albert Louvot, Olivier Schneider

We present a measurement of the branching fraction and time-dependent CP violation parameters in B-0 -> a(1)(+/-)(1260)pi(-/+) decays. The results are obtained from the final data sample containing 772 x 10(6) B (B) over bar pairs collected at the Gamma(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We obtain the product branching fraction B(B-0 -> a(1)(+/-)(1260)pi(-/+)) x B(a(1)(+/-)(1260) -> pi(+/-)pi(-/+)pi(+/-)) = (11.1 +/- 1.0(stat) +/- 1.4(syst)) x 10(-6) and an upper limit on the product branching fraction for a possible decay with the same final state B(B-0 -> a(2)(+/-)(1320)pi(-/+)) x B(a(2)(+/-)(1320) -> pi(+/-)pi(-/+)pi(+/-)) a(1)(+/-)(1260)pi(-/+) decays with 3.1 sigma significance. The rate where the a(1)(+/-) 1 does not contain the spectator quark from the B meson is found to dominate the rate where it does at the 4.1 sigma level. However, there is no evidence for either time-and flavor-integrated direct CP violation or flavor-dependent direct CP violation.

Amer Physical Soc2012

Chargement