scholarly journals GLOBAL FITS TO THE CABIBBO–KOBAYASHI–MASKAWA MATRIX: UNITARITY CONDITION METHOD VERSUS STANDARD UNITARITY TRIANGLES APPROACH

2005 ◽  
Vol 20 (23) ◽  
pp. 1709-1721 ◽  
Author(s):  
PETRE DITA
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Fine Tuning ◽  
Unitarity Condition ◽  
Matrix Elements ◽  
Unitarity Triangle ◽  
Simple Criterion ◽  
Ckm Matrix ◽  
Condition Method ◽  
Global Fit

The aim of the paper is to make a comparison between the unitarity condition method and the standard version of the unitarity triangle approach by using as parameters four independent moduli |Uij|. This choice is motivated by the measurability property and leads to a simple criterion for the separation of unistochastic matrices from the double stochastic ones, whose fulfillment is the key point of any global fit for the CKM entries. In our formulation both the methods are exact, do not depend on any assumption as the smallness of some parameter and both can be used to global fits in the quark and fermion sectors. Monte Carlo simulations show that the separation criterion puts very strong conditions requiring a fine tuning of all the CKM matrix elements.

scholarly journals B DECAYS ON THE LATTICE AND RESULTS FOR PHENOMENOLOGY

2005 ◽  
Vol 20 (16) ◽  
pp. 3651-3653
Author(s):  
MATTHEW WINGATE ◽  
CHRISTINE DAVIES ◽  
ALAN GRAY ◽  
EMEL GULEZ ◽  
JUNKO SHIGEMITSU ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Form Factors ◽  
Matrix Elements ◽  
B Decays ◽  
Ckm Matrix ◽  
Decay Constants ◽  
Lattice Monte Carlo ◽  
Ckm Matrix Elements ◽  
Fermion Action

Lattice Monte Carlo simulations now include the effects of 2 light sea quarks and 1 strange sea quark through the use of an improved staggered fermion action. Consequently, results important to phenomenology are free of the approximate 10% errors inherent in the quenched approximation. This talk reports on calculations of the B and Bs, decay constants and B → πℓν form factors. Accurate determinations of these quantities will lead to tighter constraints on CKM matrix elements.

scholarly journals IMPLICATIONS OF THE UNITARITY TRIANGLE "uc" FOR J, δ AND |VCKM| ELEMENTS

2000 ◽  
Vol 15 (40) ◽  
pp. 2363-2372 ◽  
Author(s):  
MONIKA RANDHAWA ◽  
V. BHATNAGAR ◽  
P. S. GILL ◽  
M. GUPTA
Keyword(s):  
Matrix Elements ◽  
Unitarity Triangle ◽  
Ckm Matrix ◽  
Ckm Matrix Elements ◽  
Invariant Parameter

The Jarlskog rephasing invariant parameter |J| is evaluated using one of the six unitarity triangles involving well-known CKM matrix elements |Vud|, |Vus|, |Vub/Vcb|, |Vcd|, |Vcs|, and |Vcb|. With PDG2000 values of |Vud| etc. as input, we obtain |J|= (2.71±1.12)×10-5, which in the PDG representation of CKM matrix leads to the range 21° to 159° for the CP violating phase δ. The CKM matrix elements evaluated using this range of δ are in agreement with the PDG CKM matrix. The implications of refinements in the input on |J|, δ and CKM matrix elements have also been studied.

scholarly journals The role of colour flows in matrix element computations and Monte Carlo simulations

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Stefano Frixione ◽  
Bryan R. Webber
Keyword(s):  
Monte Carlo ◽  
Matrix Element ◽  
Monte Carlo Simulations ◽  
Closed Form ◽  
Parton Shower ◽  
Natural Generalization ◽  
Tree Level ◽  
Matrix Elements ◽  
Soft Radiation

Abstract We discuss how colour flows can be used to simplify the computation of matrix elements, and in the context of parton shower Monte Carlos with accuracy beyond leading-colour. We show that, by systematically employing them, the results for tree-level matrix elements and their soft limits can be given in a closed form that does not require any colour algebra. The colour flows that we define are a natural generalization of those exploited by existing Monte Carlos; we construct their representations in terms of different but conceptually equivalent quantities, namely colour loops and dipole graphs, and examine how these objects may help to extend the accuracy of Monte Carlos through the inclusion of subleading-colour effects. We show how the results that we obtain can be used, with trivial modifications, in the context of QCD+QED simulations, since we are able to put the gluon and photon soft-radiation patterns on the same footing. We also comment on some peculiar properties of gluon-only colour flows, and their relationships with established results in the mathematics of permutations.

An up-to-date determination of the CKM matrix elements and of the unitarity triangle on the basis of the available experimental results

1999 ◽  
Vol 112 (10) ◽  
pp. 1229-1237
Author(s):  
M. Bargiotti ◽  
A. Bertin ◽  
M. Bruschi ◽  
M. Capponi ◽  
S. de Castro ◽  
...  
Keyword(s):  
Experimental Results ◽  
Matrix Elements ◽  
Unitarity Triangle ◽  
Ckm Matrix ◽  
Ckm Matrix Elements

IMPLICATIONS OF "4 TEXTURE ZEROS" MASS MATRICES BASED ON G × SU(3)fam

1996 ◽  
Vol 11 (27) ◽  
pp. 4805-4814
Author(s):  
P. S. GILL ◽  
MANMOHAN GUPTA
Keyword(s):  
Phenomenological Models ◽  
Present Model ◽  
Unified Theory ◽  
Grand Unified Theory ◽  
Matrix Elements ◽  
Unitarity Triangle ◽  
Specific Mass ◽  
Family Symmetry ◽  
Ckm Matrix ◽  
Mass Matrices

Texture specific mass matrices generated from the grand unified theory with global family symmetry, have been investigated in the context of latest data regarding [Formula: see text], |Vub|, |Vcb|, |Vtd|, |Vts| and other parameters depending on CKM matrix elements. Unlike several other phenomenological models, the present model not only accommodates the value of [Formula: see text] in the range 150–240 GeV, encompassing the CDF and D0 values, but is also able to reproduce |Vcb| = .038 ± .003 and |Vub/Vcb| = 0.08 ± 0.02, whereas |Vtd| is predicted in the range .005–.014. Further, the angles of the unitarity triangle, related to the CP-violating asymmetries, are in the ranges -1.0 ≤ sin 2α ≤ -.1, .6 ≤ sin 2α ≤ 1.0 and .48 ≤ sin 2β ≤ .56, in agreement with other recent calculations.

Low-voltage EDS of magnesium ferrite Dendrites in a FEG-SEM

1996 ◽  
Vol 54 ◽  
pp. 478-479
Author(s):  
Matthew T. Johnson ◽  
Ian M. Anderson ◽  
Jim Bentley ◽  
C. Barry Carter
Keyword(s):  
Monte Carlo ◽  
Quantitative Analysis ◽  
Monte Carlo Simulations ◽  
Cross Section ◽  
Spatial Resolution ◽  
Low Voltage ◽  
Magnesium Ferrite ◽  
X Ray ◽  
Interaction Volume ◽  
Ferrite Spinel

Energy-dispersive X-ray spectrometry (EDS) performed at low (≤ 5 kV) accelerating voltages in the SEM has the potential for providing quantitative microanalytical information with a spatial resolution of ∼100 nm. In the present work, EDS analyses were performed on magnesium ferrite spinel [(MgxFe1−x)Fe2O4] dendrites embedded in a MgO matrix, as shown in Fig. 1. spatial resolution of X-ray microanalysis at conventional accelerating voltages is insufficient for the quantitative analysis of these dendrites, which have widths of the order of a few hundred nanometers, without deconvolution of contributions from the MgO matrix. However, Monte Carlo simulations indicate that the interaction volume for MgFe2O4 is ∼150 nm at 3 kV accelerating voltage and therefore sufficient to analyze the dendrites without matrix contributions.Single-crystal {001}-oriented MgO was reacted with hematite (Fe2O3) powder for 6 h at 1450°C in air and furnace cooled. The specimen was then cleaved to expose a clean cross-section suitable for microanalysis.

MONTE CARLO SIMULATIONS OF ELECTRON DRIFT VELOCITIES IN THE NOBLE GASES AND THEIR MIXTURES

1979 ◽  
Vol 40 (C7) ◽  
pp. C7-63-C7-64
Author(s):  
A. J. Davies ◽  
J. Dutton ◽  
C. J. Evans ◽  
A. Goodings ◽  
P.K. Stewart
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Noble Gases ◽  
Electron Drift
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