English
Related papers

Related papers: Isospin violation in epsilon'

200 papers

We consider the impact of isospin violation on the analysis of K-> pi pi decays. We scrutinize, in particular, the phenomenological role played by the additional weak amplitude, of |Delta I|=5/2 in character, incurred by the presence of…

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

We have compared the decay rates of K_L and K_S to \pi^+ \pi^- and \pi^0 \pi^0 final states using a subset of the data from the KTeV experiment (E832) at Fermilab. We find that the direct-CP-violation parameter Re(\epsilon'/\epsilon) is…

High Energy Physics - Experiment · Physics 2012-08-27 KTeV Collaboration

We calculate the rate for $D_s^* \rightarrow D_s \pi^0$ decay using Chiral Perturbation Theory. This isospin violating process results from $\pi^0$ - $\eta$ mixing, and its amplitude is proportional to $(m_d - m_u)/\bigl(m_s-(m_u+m_d)/2…

High Energy Physics - Phenomenology · Physics 2009-10-28 Peter Cho , Mark B. Wise

Using the recent first lattice results of the RBC-UKQCD collaboration for $K \to \pi\pi$ decays, we perform a phenomenological analysis of $\epsilon_K^{\prime}/\epsilon_K$ and find a discrepancy between SM prediction and experiments by…

High Energy Physics - Phenomenology · Physics 2017-04-05 Teppei Kitahara , Ulrich Nierste , Paul Tremper

We use chiral perturbation theory to evaluate the scattering amplitude for the process Pi^+ K^- to Pi^+ K^- at leading and next-to-leading orders in the chiral counting and in the presence of isospin breaking effects. We also discuss the…

High Energy Physics - Phenomenology · Physics 2011-09-13 A. Nehme

The strong isospin-breaking correction, Omega_{st}, which appears in estimates of the Standard Model value for the direct CP-violating ratio epsilon'/epsilon, is evaluated to next-to-leading order (NLO) in the chiral expansion using Chiral…

High Energy Physics - Phenomenology · Physics 2014-11-17 C. E. Wolfe , K. Maltman

The effects of isospin violation on the neutral weak magnetic form factor of the proton are studied using two-flavour chiral perturbation theory. The first nonzero contributions appear at O(p^4) in the small-momentum expansion, and the…

High Energy Physics - Phenomenology · Physics 2009-12-30 Randy Lewis , Nader Mobed

It is shown that isospin-breaking corrections to the pion-deuteron scattering length can be very large, because of the vanishing of the isospin-symmetric contribution to this scattering length at leading order in chiral perturbation theory.…

Nuclear Theory · Physics 2008-11-26 Ulf-G. Meißner , Udit Raha , Akaki Rusetsky

I discuss low-energy pion-nucleon scattering in the framework of chiral perturbation theory. I argue that using this theoretical method one is able to handle the in some cases tremendous experimental accuracy (for the low partial waves). I…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ulf-G. Meißner

We show that in the context of large extra dimensions enough CP violation can be obtained from the spontaneous breaking in a simple non-SUSY model, which is usually considered not to cause the spontaneous CP violation. We estimate…

High Energy Physics - Phenomenology · Physics 2007-05-23 Yutaka Sakamura

CP violation in K and B decays is reviewed in the Standard Model (SM) and beyond the SM. In K decays, one is seeking first evidence for CP violation in direct $K\to \pi\pi$ decays. This would not give a precise quantitative test for the…

High Energy Physics - Phenomenology · Physics 2014-11-17 Michael Gronau

We examine the effect of isospin-violating meson-nucleon coupling constants on low-energy pion-nucleon scattering. We compute the couplings in the context of a nonrelativistic quark model. The difference between the up and down constituent…

Nuclear Theory · Physics 2011-02-01 Jorge Piekarewicz

We report measurements of CP violation parameters in $B^0 \to K^0 \pi^0$ decays based on a data sample of $657 \times 10^6 B\bar{B}$ pairs collected with the Belle detector at the KEKB $e^+ e^-$ asymmetric-energy collider. We use $B^0 \to…

High Energy Physics - Experiment · Physics 2019-08-13 M. Fujikawa , Y. Yusa

I give a short presentation of the theoretical prediction of epsilon-prime/epsilon. Short distance and especially long distance aspects of the computation is discussed. I consentrate on the general framework and the chiral quark model…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. O. Eeg

The direct CP violation parameter Re(epsilon'/epsilon) has been measured from the decay rates of neutral kaons into two pions using the NA48 detector at the CERN SPS. With 3.3 million KL->pi0pi0 events collected during the 1998 and 1999…

High Energy Physics - Experiment · Physics 2012-08-27 NA48 Collaboration

Two aspects of isospin breaking in the decay $K^\pm \to \pi^0 \pi^0 e^\pm \stackrel{_{(-)}}{\nu_e}$ are studied and discussed. The first addresses the possible influence of the phenomenological description of the unitarity cusp on the…

High Energy Physics - Phenomenology · Physics 2015-01-29 Véronique Bernard , Sébastien Descotes-Genon , Marc Knecht

Extraction of the nucleon's strange form factors from experimental data requires a quantitative understanding of the unavoidable contamination from isospin violation. A number of authors have addressed this issue during the past decade, and…

Nuclear Theory · Physics 2008-11-26 Randy Lewis

We study direct CP violation in $B^\pm \to \rho^\pm\rho^0(\omega) \to \rho^\pm\pi^+\pi^-$ and focus specifically on the rate asymmetry in the $\rho^0$-$\omega$ interference region. Here the strong phase is dominated by isospin violation, so…

High Energy Physics - Phenomenology · Physics 2009-10-30 S. Gardner , H. B. O'Connell , A. W. Thomas

We present a new measurement of the time-dependent CP-violating parameters in B0 --> pi+ pi- decays with 275 x 10^6 BB-bar pairs collected with the Belle detector at the KEKB asymmetric-energy e+e- collider operating at the Upsilon(4S)…

High Energy Physics - Experiment · Physics 2008-11-26 Belle Collaboration , K. Abe

We calculate the decay $\eta\to3\pi$ at next-to-next-to-leading order or order $p^6$ in Chiral Perturbation Theory. The corrections are somewhat larger than was indicated by dispersive estimates. We present numerical results for the Dalitz…

High Energy Physics - Phenomenology · Physics 2009-01-06 Johan Bijnens , Karim Ghorbani