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Related papers: Isospin-breaking effects on alpha extracted in B -…

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Theoretical errors in the extraction of alpha from B -> pi^+ pi^-, rho^+ rho^-, rho pi decays are usually given in terms of upper bounds on alpha_eff-alpha obtained from isospin or from SU(3) relations, where alpha_eff is measured through…

High Energy Physics - Phenomenology · Physics 2010-04-05 M. Gronau , E. Lunghi , D. Wyler

We study the implications of several recent high-precision measurements of the pion form factor in the region of the rho-omega interference "shoulder" for (i) the extraction of the rho-omega mixing matrix element, Pi_{\rho\omega}(m_rho^2),…

High Energy Physics - Phenomenology · Physics 2010-04-30 C. E. Wolfe , K. Maltman

Isospin-breaking effects, in particular those associated with electroweak-penguin contributions and pi0-eta,eta' mixing, have long been known to affect the Standard Model prediction of Re(epsilon'/epsilon) in a significant manner. We have…

High Energy Physics - Phenomenology · Physics 2011-02-01 S. Gardner

Defining a most economical parametrization of time-dependent B-> rho^\pm pi^\mp decays, including a measurable phase alpha_{eff} which equals the weak phase alpha in the limit of vanishing penguin amplitudes, we propose two ways for…

High Energy Physics - Phenomenology · Physics 2009-11-10 M. Gronau , J. Zupan

We discuss how to extract the weak phase alpha from present data on B--> rho+- pi-+ decays. Introducing alpha_{eff} and constraining the difference from alpha using flavor SU(3), one arrives at alpha=(95+- 16) degrees, if a testable…

High Energy Physics - Phenomenology · Physics 2009-11-10 J. Zupan

The 2.5 sigma discrepancy between theory and experiment observed in the difference A_CP(B^- --> pi^0 K^-)-A_CP(Bbar^0 --> pi^+ K^-) can be explained by a new electroweak penguin amplitude. Motivated by this result, we analyse the purely…

High Energy Physics - Phenomenology · Physics 2015-03-17 Lars Hofer , Dominik Scherer , Leonardo Vernazza

An isospin analysis of $B\to\pi\pi$ decays yields $\sin 2\alpha$, where $\alpha$ is the usual CKM angle $\alpha\equiv arg [-V_{td}V_{tb}^\ast /(V_{ud}V_{ub}^\ast)]$, without hadronic uncertainty if isospin is a perfect symmetry. Isospin,…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Gardner

In the analysis of \epsilon^\prime/\epsilon it has been traditional to consider the isospin-breaking effects arising from electroweak-penguin contributions and from \pi^0-\eta and \pi^0-\eta^\prime mixing, yet additional isospin-violating…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Gardner , G. Valencia

The 2.5 sigma discrepancy between theory and experiment observed in the difference Delta ACP = ACP(B- --> pi0 K-) - ACP(Bb0 --> pi+ K-) can be explained by a new electroweak (EW) penguin amplitude. Motivated by this result, we have analyzed…

High Energy Physics - Phenomenology · Physics 2010-12-17 Lars Hofer , Dominik Scherer , Leonardo Vernazza

A way to explain the puzzling difference between the pion form factor as measured in e+ e- annihilations and in tau decays is discussed. We show that isospin symmetry breaking, beside the already identified effects, produces also a full…

High Energy Physics - Phenomenology · Physics 2008-05-14 Maurice Benayoun

The effect of the penguin amplitude on extracting $\alpha$ from CP asymmetries in $B^0\to \rho^+\rho^-$ decays is studied using information on the SU(3)-related penguin amplitude in $B^+\to K^{*0}\rho^+$. Conservative bounds on…

High Energy Physics - Phenomenology · Physics 2009-11-11 Martin Beneke , Michael Gronau , Johannes Rohrer , Michael Spranger

Using psi(2S) --> pi+ pi- J/psi, J/psi --> gamma eta' events acquired with the CLEO-c detector at the CESR e+e- collider, we make the first observations of the decays eta' --> pi+ pi- pi0 and eta' --> pi+ pi- e+ e-, measuring absolute…

High Energy Physics - Experiment · Physics 2010-04-08 CLEO Collaboration , P. Naik

In terms of effective field theory and mixed propagator approach, we show that there is a larger hidden effect of isospin breaking in $\rho^0\to\pi^0\gamma$ decay due to an $\omega$ exchange, $\rho^0\to\omega\to\pi^0\gamma$. The branching…

High Energy Physics - Phenomenology · Physics 2007-05-23 Xiao-Jun Wang , Ji-Hao Jiang , Mu-Lin Yan

For direct CP-violation in $K\to\pi\pi$ decays, the usual isospin-breaking effects at the percent level are amplified by the dynamics behind the $\Delta I=1/2$ rule and conventionally encoded in $\Omega_{\rm IB}$ parameters. The updated…

High Energy Physics - Phenomenology · Physics 2020-08-26 Andrzej J. Buras , Jean-Marc Gerard

Quasi two-body decays B^0(t)-> a_1^{+-}(1260) pi^{-+} identified by four charged pions determine a phase alpha_eff, which is equal to the weak phase alpha in the limit of vanishing penguin amplitudes. Applying flavor SU(3) to these decays…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Gronau , J. Zupan

This is the first of a series of papers devoted to a detailed analysis of isospin-breaking effects in the $\pi \pi$ scattering amplitude and the vector form factor of the pion. Isospin breaking originates from the mass difference between up…

High Energy Physics - Phenomenology · Physics 2025-11-13 Gilberto Colangelo , Martina Cottini , Jacobo Ruiz de Elvira

I present two disparate examples of isospin violation in hadronic B-decays. In the first, the presence of \rho^0-\omega mixing in the decay B^\mp\to\rho^\mp\rho^0(\omega)\to\rho^\mp\pi^+ \pi^- permits the extraction of sgn(\sin \alpha),…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Gardner

We discuss how experiments measuring B -> pi pi and B -> rho rho may be used to search for a Delta I = 5/2 amplitude component. This component could be the explanation for a recent (albeit very tentative) hint from B(Bbar) -> rho rho decays…

High Energy Physics - Phenomenology · Physics 2014-11-18 F. J. Botella , David London , Joao P. Silva

In this paper we improve and extend a recent analysis which showed that the rho-omega mixing amplitude cannot be unambiguously extracted from the pion electromagnetic form-factor in a model independent way. In particular, we focus on the…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. G. Williams , H. B. O'Connell , A. W. Thomas

We show that ratios of tree and penguin amplitudes in B-> K*pi and B->rho K are two to three times larger than in B-> K pi. This allows for considerably larger CP asymmetries in the former processes than the 10% asymmetry measured in B0 ->…

High Energy Physics - Phenomenology · Physics 2010-05-25 Michael Gronau , Dan Pirjol , Jure Zupan
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