PARAMETER OF K MESON MIXING AND NON-ABELIAN ANOMALY

1992 ◽  
Vol 07 (27) ◽  
pp. 6833-6844 ◽  
Author(s):  
V.M. BELYAEV

The amplitude of K meson mixing is calculated. Pseudo-Goldstone fields are considered as phases of γ5 transformation of quark fields. A formalism for description of K and π mesons in this approach is given. The amplitude is expressed in terms of matrix elements [Formula: see text] and [Formula: see text]. It is shown that there is a relation between [Formula: see text] and [Formula: see text]. This relation is in good agreement with known values for amplitudes. The result for the parameter of K meson mixing is [Formula: see text]. From general consideration it is shown that the correction to the vacuum factorization hypothesis must be positive.

2021 ◽  
Vol 81 (3) ◽  
Author(s):  
Y. Amhis ◽  
Sw. Banerjee ◽  
E. Ben-Haim ◽  
F. U. Bernlochner ◽  
M. Bona ◽  
...  

AbstractThis paper reports world averages of measurements of b-hadron, c-hadron, and $$\tau $$ τ -lepton properties obtained by the Heavy Flavour Averaging Group using results available through September 2018. In rare cases, significant results obtained several months later are also used. For the averaging, common input parameters used in the various analyses are adjusted (rescaled) to common values, and known correlations are taken into account. The averages include branching fractions, lifetimes, neutral meson mixing parameters, $$C\!P$$ C P  violation parameters, parameters of semileptonic decays, and Cabibbo–Kobayashi–Maskawa matrix elements.


2020 ◽  
Vol 128 (8) ◽  
pp. 1077
Author(s):  
В.П. Булычев ◽  
М.В. Бутурлимова ◽  
К.Г. Тохадзе

The frequencies and intensities of IR absorption bands of symmetric and asymmetric H-bonded complexes [FL1FL2F]- (L1, L2 = K-meson Ka, proton H, deuton D, and triton T) are calculated. The equilibrium configuration and potential energy and dipole moment surfaces of isotopologues [FL1FL2F]- were calculated by the MP2/6-311++G(3df,3pd) method with the basis set superposition error taken into account. The calculations of spectral parameters with allowance for anharmonic interactions of all vibrations were carried out using the second-order vibrational perturbation theory. Variation of Li and L2 masses in wide regions allowed significant changes in the forms of normal vibrations and values of anharmonic interaction constants upon isotopic substitution to be obtained. The trends in the changes of spectral parameters were determined upon transition from one symmetric isotopologue to another and upon transition from symmetric to asymmetric isotopologues. The D-F stretching band frequency predicted for [FHFDF]- is in good agreement with the experimental value. The assignment of this band was improved.


2017 ◽  
Vol 26 (05) ◽  
pp. 1750032 ◽  
Author(s):  
Anwer A. Al-Sammarraie ◽  
M. L. Inche Ibrahim ◽  
Muna Ahmed Saeed ◽  
Fadhil I. Sharrad ◽  
Hasan Abu Kassim

The electric and magnetic transitions in the [Formula: see text]Mg nucleus are studied based on the calculations of the longitudinal and the transverse electron scattering form factors. The universal sd-shell model Hamiltonian (USDA) is used for calculations. The wave functions of radial single-particle matrix elements are calculated using the Skyrme potential. For the longitudinal form factors, a good agreement is obtained between the calculations and the experimental data. For the transverse form factors, the effective [Formula: see text] factors are made as adjustable parameters in order to describe the experimental data.


1977 ◽  
Vol 55 (13) ◽  
pp. 1137-1144 ◽  
Author(s):  
C. R. Hirning ◽  
D. G. Burke

Levels in the deformed even–even nucleus 152Sm have been populated by the (t,α) reaction using beams of 15 MeV tritons from the model FN tandem Van de Graaff accelerator at the Los Alamos Scientific Laboratory. For the initial experiments in the series the reaction products were analyzed in an Elbek magnetic spectrograph and detected with nuclear emulsions. Those done later made use of the Q3D magnetic spectrometer and helical-cathode focal plane detector. On the basis of levels observed in adjacent odd-Z nuclei and some previous (α,2nγ) results, a rotational band built on the Kπ = 5−, 5/2+[413] + 5/2−[532] two-quasiparticle state has been identified. A Coriolis coupling calculation has been done, which gives good agreement with experimental energies and cross sections when an attenuation factor of 0.31 is used for the Coriolis matrix elements.


2013 ◽  
Vol 27 (11) ◽  
pp. 1350037 ◽  
Author(s):  
SOMIA ABD-ELNABI ◽  
K. I. OSMAN

The influence of Doppler broadening on a four-level N-type atomic system has been investigated in the presence of spontaneous generating coherence. The atomic system interacting with three electromagnetic fields and includes the nonradiative decay, the effect of co- and counter-propagation of the fields is considered. The probe susceptibility behaviors can be modified by Doppler broadening via nonperturbative treatments of the density matrix elements solution in the absence and presence of the spontaneous generating coherence. Some interesting features are enhanced for the spectral behaviors and controllability of electromagnetically induced transparency, which were found to be in good agreement to some experimental results without including Zeeman sublevels to the system.


2004 ◽  
Vol 19 (12) ◽  
pp. 921-925 ◽  
Author(s):  
A. BHATTACHARYA ◽  
S. N. BANERJEE ◽  
B. CHAKRABARTI ◽  
S. BANERJEE

The ratios of Bd and Bs meson decay constant have been estimated using the variational method in conjunction with the relativistic Hamiltonian of the heavy meson in the framework of the statistical model. The ratio of CKM matrix elements [Formula: see text] has been extracted from [Formula: see text] mixing using the estimated decay constants and ratio of Bd and Bs mass differences. The results are found to be in good agreement with the existing theoretical and experimental predictions.


2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Zhan Sun

Abstract In this paper, we present a detailed next-to-leading-order (NLO) study of J/ψ angular distributions in e+e−→ J/ψ + ηc, χcJ (J = 0, 1, 2) within the nonrelativistic QCD factorization (NRQCD). The numerical NLO expressions for total and differential cross sections, i.e., $$ \frac{d\sigma}{d\cos \theta } $$ dσ d cos θ = A + B cos2θ, are both derived. With the inclusion of the newly-calculated QCD corrections to A and B, the αθ (= B/A) parameters in J/ψ + χc0 and J/ψ + χc1 are moderately enhanced, while the magnitude of αθJ/ψ+χc2 is significantly reduced; regarding the production of J/ψ + ηc, the αθ value remains unchanged. By comparing with experiment, we find the predicted αθJ/ψ+ηc is in good agreement with the Belle measurement; however, αθJ/ψ+χc0 is still totally incompatible with the experimental result, and this discrepancy seems to hardly be cured by proper choices of the charm-quark mass, the renormalization scale, and the NRQCD matrix elements.


1984 ◽  
Vol 39 (12) ◽  
pp. 1168-1171
Author(s):  
C. T. Yap ◽  
E. L. Saw

Although experimental values of the Fermi nuclear matrix elements vary widely from about 1 × 10-3 to 40 × 10-3 for isospin-forbidden 0+→0+ β transitions, theoretical calculations using the Coulomb potential and Nilsson wave functions yielded values of MF in reasonably good agreement, except that of 234Np. However, our calculation of MF for this decay as a function of the deformation parameter β yielded a value of MF in good agreement with experiment for values of β between 0.1 and 0.2.


1967 ◽  
Vol 45 (5) ◽  
pp. 1661-1673 ◽  
Author(s):  
Maurice Cohen ◽  
Paul S. Kelly

Hartree–Fock wave functions for a number of S, P, and D states of the lithium isoelectronic sequence have been calculated, using a simplified procedure described in an earlier paper. Transition matrix elements for all permitted dipole transitions between these states have been computed using both the dipole length and the dipole velocity formulations. The results are in good agreement with earlier calculations.


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