scholarly journals Implications of tau data for CP violation in K decays

Author(s):  
Antonio Rodríguez Sánchez

The \bm{D=6}𝐃=6 contribution of the Operator Product Expansion (OPE) of the \bm{\mathrm{VV-AA}}VV−AA correlator of quark currents can be related to hadronic matrix elements associated to CP violation in non-leptonic kaon decays. We use those relations to find an updated value for \bm{\langle(\pi\pi)_{I=2}|\mathcal{Q}_{8}|K\rangle}⟨(𝛑𝛑)𝐈=2|𝒬8|𝐊⟩ in the chiral limit using the updated ALEPH spectral function. Taking instead values of the matrix elements from the lattice to obtain the \bm{D=6}𝐃=6 vacuum elements provides a new short-distance constraint that allows for an inclusive determination of \bm{f_{\pi}}𝐟𝛑 and an updated value for the \bm{D=8}𝐃=8 condensate.

2001 ◽  
Vol 16 (supp01c) ◽  
pp. 1228-1230
Author(s):  
JOHN F. DONOGHUE

Most past work on weak nonleptonic decays has mixed dimensional regularization in the weak operator product expansion with some form of a cutoff regularization in the evaluation of the matrix elements. Even with the usual technique of matching the two schemes, this combination misses physics at short distance which can be described by dimension eight (and higher dimension) operators. I describe some recent work with V. Cirigliano and E. Golowich which clarifies these effects and provides a numerical estimate suggesting that they are important.


2004 ◽  
Vol 19 (07) ◽  
pp. 1004-1016 ◽  
Author(s):  
K. R. SCHUBERT

The present status of experimental results for the magnitudes of Cabibbo-Kobayashi-Maskawa matrix elements is reviewed and used for a unitarity test. The matrix is found to be unitary within ±1.8 standard deviations. The matrix violates CP-symmetry and the size of its CP-violation, as derived from only magnitude measurements and unitarity, is in perfect agreement with the observed CP-violations in K and B meson decays.


2000 ◽  
Vol 2000 (08) ◽  
pp. 023-023 ◽  
Author(s):  
Maarten Golterman ◽  
Elisabetta Pallante
Keyword(s):  

2018 ◽  
Vol 175 ◽  
pp. 13026
Author(s):  
Vittorio Lubicz ◽  
Lorenzo Riggio ◽  
Giorgio Salerno ◽  
Silvano Simula ◽  
Cecilia Tarantino

We present a lattice determination of the vector and scalar form factors of the D → π(K)lv semileptonic decays, which are relevant for the extraction of the CKM matrix elements |Vcd| and |Vcs| from experimental data. Our analysis is based on the gauge configurations produced by the European Twisted Mass Collaboration with Nf = 2 + 1 +1 flavors of dynamical quarks. We simulated at three different values of the lattice spacing and with pion masses as small as 210 MeV. The matrix elements of both vector and scalar currents are determined for a plenty of kinematical conditions in which parent and child mesons are either moving or at rest. Lorentz symmetry breaking due to hypercubic effects is clearly observed in the data and included in the decomposition of the current matrix elements in terms of additional form factors. After the extrapolations to the physical pion mass and to the continuum limit the vector and scalar form factors are determined in the whole kinematical region from q2 = 0 up to [see formula in PDF] accessible in the experiments, obtaining a good overall agreement with experiments, except in the region at high values of q2 where some deviations are visible.


2016 ◽  
Vol 31 (30) ◽  
pp. 1630031 ◽  
Author(s):  
Santiago Peris ◽  
Diogo Boito ◽  
Maarten Golterman ◽  
Kim Maltman

In this review, we discuss why, in the determination of [Formula: see text] from hadronic [Formula: see text] decays, two important assumptions made in most of previous analyses, namely the neglect of higher-dimension condensates and of duality violations (DVs), have introduced uncontrolled systematic errors into this determination. Although the use of pinched weights is usually offered as a justification of these assumptions, we explain why it is not possible to simultaneously suppress these two contributions; particularly since the Operator Product Expansion (OPE) is expected to be an asymptotic, rather than a convergent expansion. There is not only experimental and theoretical evidence for DVs but they also affect the extraction of [Formula: see text].


2013 ◽  
Vol 22 (05) ◽  
pp. 1330012 ◽  
Author(s):  
SINYA AOKI ◽  
JANOS BALOG ◽  
TAKUMI DOI ◽  
TAKASHI INOUE ◽  
PETER WEISZ

We review recent investigations on the short distance behaviors of potentials among baryons, which are formulated through the Nambu–Bethe–Salpeter (NBS) wave function. After explaining the method to define the potentials, we analyze the short distance behavior of the NBS wave functions and the corresponding potentials by combining the operator product expansion (OPE) and a renormalization group (RG) analysis in the perturbation theory (PT) of QCD. These analytic results are compared with numerical results obtained in lattice QCD simulations.


1979 ◽  
Vol 57 (6) ◽  
pp. 793-800 ◽  
Author(s):  
Marie Fontaine ◽  
Pierre Amiot

We develop a hydrodynamical method to calculate the inertia matrix elements for highly deformed nuclei. The nuclear velocity field is incompressible but is not limited to the adiabatic case. The formulation is also more general than Werner–Wheeler's. It is shown that off-diagonal terms play an important role in the determination of the normal modes of fission by diagonalization of the matrix.


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