scholarly journals NONFACTORIZABLE LONG DISTANCE CONTRIBUTIONS IN COLOR SUPPRESSED DECAYS OF B MESONS

1998 ◽  
Vol 13 (25) ◽  
pp. 4325-4338 ◽  
Author(s):  
K. TERASAKI
Keyword(s):  
Experimental Data ◽  
B Mesons ◽  
Branching Ratios ◽  
Unknown Parameters ◽  
Long Distance

[Formula: see text], D*π, [Formula: see text] and J/ψπ decays are studied. Their amplitude is given by a sum of factorized and nonfactorizable ones. The latter which is estimated by using a hard pion approximation is rather small in color favored [Formula: see text] and D*π decays but still can efficiently interfere with the main amplitude given by the factorization. In the color suppressed [Formula: see text] and J/ψπ decays, the nonfactorizable contribution is very important. The sum of the factorized and nonfactorizable amplitudes can reproduce well the existing experimental data on the branching ratios for the color favored [Formula: see text] and D*π and the color suppressed [Formula: see text] and J/ψπ decays by taking reasonable values of unknown parameters involved.

scholarly journals Study on branching ratios and direct CP asymmetries of D → PV decays

2014 ◽  
Vol 29 ◽  
pp. 1460209 ◽  
Author(s):  
Qin Qin ◽  
Hsiang-Nan Li ◽  
Cai-Dian Lü ◽  
Fu-Sheng Yu
Keyword(s):  
Experimental Data ◽  
Pseudoscalar Meson ◽  
Short Distance ◽  
D Mesons ◽  
Branching Ratios ◽  
Matrix Elements ◽  
Long Distance ◽  
Global Fit ◽  
Belle Ii ◽  
Cp Asymmetries

We study the non-leptonic two-body decays of D mesons decaying into one pseudoscalar meson (P) and one vector meson (V) in the factorization-asisted topological-amplitude approach. In this approach, the decay amplitudes are factorized into two parts, the short-distance contribution (Wilson coefficients) and the long-distance contribution (hadronic matrix elements). We predict the branching ratios of D → PV decays using a global fit with the non-perturbative parameters. Our results agree well with the experimental data. We also predict the direct CP asymmetries by combining short-distance dynamics associated with penguin operators and long-distance hadronic matrix elements determined by branching ratios. The large asymmetries in D+ → π+ρ0 and [Formula: see text] may be measurable in the LHCb and future Belle II experiments.

scholarly journals A Monte Carlo approach for determining cluster evaporation rates from concentration measurements

2016 ◽  
Author(s):  
Oona Kupiainen-Määttä
Keyword(s):  
Experimental Data ◽  
Monte Carlo ◽  
Markov Chain ◽  
Sulfuric Acid ◽  
Markov Chain Monte Carlo ◽  
Mass Spectrometer ◽  
Large Fraction ◽  
Cluster Formation ◽  
Unknown Parameters ◽  
Ammonia Clusters

Abstract. Evaporation rates of small negatively charged sulfuric acid–ammonia clusters are determined by combining detailed cluster formation simulations with cluster distributions measured at CLOUD. The analysis is performed by varying the evaporation rates with Markov chain Monte Carlo (MCMC), running cluster formation simulations with each new set of evaporation rates and comparing the obtained cluster distributions to the measurements. In a second set of simulations, the fragmentation of clusters in the mass spectrometer due to energetic collisions is studied by treating also the fragmentation probabilities as unknown parameters and varying them with MCMC. This second set of simulations results in a better fit to the experimental data, suggesting that a large fraction of the observed HSO4− and HSO4− ⋅ H2SO4 signals may result from fragmentation of larger clusters, most importantly the HSO4− ⋅ (H2SO4)2 trimer.

scholarly journals Parameter Estimation of DC Motor using Adaptive Transfer Function Based on Nelder-Mead Optimisation

2018 ◽  
Vol 9 (3) ◽  
pp. 696 ◽  
Author(s):  
Byamakesh Nayak ◽  
Sangeeta Sahu ◽  
Tanmoy Roy Choudhury
Keyword(s):  
Experimental Data ◽  
Transfer Function ◽  
Adaptive Method ◽  
Dc Motor ◽  
Model Parameters ◽  
Current Response ◽  
Adaptive Model ◽  
Unknown Parameters ◽  
Dc Motors ◽  
Estimated Parameters

<p>This paper explains an adaptive method for estimation of unknown parameters of transfer function model of any system for finding the parameters. The transfer function of the model with unknown model parameters is considered as the adaptive model whose values are adapted with the experimental data. The minimization of error between the experimental data and the output of the adaptive model have been realised by choosing objective function based on different error criterions. Nelder-Mead optimisation Method is used for adaption algorithm. To prove the method robustness and for students learning, the simple system of separately excited dc motor is considered in this paper. The experimental data of speed response and corresponding current response are taken and transfer function parameters of  dc motors are adapted based on Nelder-Mead optimisation to match with the experimental data. The effectiveness of estimated parameters with different objective functions are compared and validated with machine specification parameters.</p>

Industrial Robot Kinematics Parameter Identification

2014 ◽  
Vol 889-890 ◽  
pp. 1136-1143
Author(s):  
Yong Gui Zhang ◽  
Chen Rong Liu ◽  
Peng Liu
Keyword(s):  
Experimental Data ◽  
Genetic Algorithms ◽  
Parameter Identification ◽  
Industrial Robot ◽  
Industrial Robots ◽  
Robot Kinematics ◽  
Kinematic Parameters ◽  
Unknown Parameters ◽  
Preliminary Measurement ◽  
Kinematics Modeling

For an industrial robots with unknown parameters, on the basis of preliminary measurement and data of the Cartesian and joints coordinates which are shown on the FlexPendant, the kinematic parameters is identified by using genetic algorithms and accurate kinematics modeling of the robot is established. Experimental data could prove the validity of this method.

B0 → J/ψf2(1270) decay in QCD factorization

2012 ◽  
Vol 90 (12) ◽  
pp. 1201-1208 ◽  
Author(s):  
Mahboobeh Sayahi ◽  
Hossein Mahraban
Keyword(s):  
Experimental Data ◽  
B Meson ◽  
Factorization Method ◽  
Branching Ratios ◽  
Hadronic Decay ◽  
Light Meson ◽  
Qcd Factorization ◽  
Effective Coefficients

In this paper, the hadronic decay B0 → J/ψf2(1270) has been analyzed using the “QCD factorization” method. The effective coefficients [Formula: see text] have been calculated for three helicity states (h = 0, +, –) which give three contributions of amplitude. We have assumed two scenarios for J/ψ. First, we have considered that J/ψ behaves as a light meson compared to the B meson and second, we have considered the mass of J/ψ in our calculations meaning that mJ/ψ/mb is held fixed. The branching ratios are calculated in these two scenarios and also in different energy scales (μ = mb, μ = mb/2, and μ = 2mb). The obtained results are in agreement with available experimental data for the second scenario and μ = 2mb.

scholarly journals Combining simulation to nonlinear fitting for the determination of rate constants of elementary reactions by using Excel spreadsheets

2012 ◽  
Vol 8 (4) ◽  
Author(s):  
Ammar M. Tighezza ◽  
Daifallah M. Aldhayan ◽  
Nouir A. Aldawsari
Keyword(s):  
Experimental Data ◽  
Numerical Integration ◽  
Chemical Kinetics ◽  
Chemical Reactions ◽  
Rate Constants ◽  
Model Equation ◽  
Rate Equations ◽  
Unknown Parameters ◽  
Elementary Reactions ◽  
Nonlinear Fitting

A common problem in chemistry is to determine parameters (constants) in an equation used to represent experimental data. Examples are fitting a set of data to a model equation (straight line or curve) to obtain unknown parameters. In chemical kinetics, a set of data is usually a number of concentrations versus time, but the model equation is not well defined! Instead of a well defined model equation we have a set of coupled ODE’s (ordinary differential equations) which represent rate equations for reactants and products. The analytical integration of these ODE’s is rarely possible. The numerical integration is the alternative. In this work are combined the simulation of chemical reactions, by using numerical integration, and nonlinear regression (curve fitting) by using “Solver add-in” of Microsoft Excel to find rate constants of elementary reactions from experimental data. This method is illustrated on three complex mechanisms. The simulation of chemical reactions in Excel spreadsheets is illustrated with/without VBA programming. The automation (automatic obtaining of rate equations from mechanism: no need of chemical kinetics knowledge from the end user!) of mechanism simulation is demonstrated on many example.

scholarly journals The Possibility of Meson-Lepton and Dilepton Resonances

1987 ◽  
Vol 40 (3) ◽  
pp. 283
Author(s):  
SR Choudhury ◽  
GC Joshi ◽  
BHJ McKellar ◽  
EW Vogt
Keyword(s):  
Experimental Data ◽  
Branching Ratios ◽  
Composite Model ◽  
Charged Leptons ◽  
Colour Octet

Recent hints in experimental data of a fJ.1T resonance at 429 MeV have led us to speculate about the possibility of meson-lepton and dilepton resonances. We show that the proposed fJ.7T resonance at 429 MeV is not in conflict with the muon g-2 measurements, and that it could be interpreted as a partner of the excited charged leptons possibly seen at CERN. Moreover, a composite model by Fritzsch and Mandelbaum predicts not only a flavour octet of meson-muon resonances of which this could be one, but also dilepton resonances which were suggested by Ramm as an explanation of the lobe structure in the fJ.7T data. The observed widths and branching ratios of the resonances can be interpreted to suggest that the colour-octet states are considerably smaller than the colour singlets.

Experimental Investigation on Stochastic Crack Growth Model of GH4133B at Fatigue-Creep

2009 ◽  
Author(s):  
Dianyin Hu ◽  
Rongqiao Wang
Keyword(s):  
Experimental Data ◽  
High Temperature ◽  
Crack Growth ◽  
Room Temperature ◽  
Deterministic Model ◽  
Hold Time ◽  
Testing Machine ◽  
Crack Size ◽  
Long Distance ◽  
Crack Growth Model

Experiments on the fatigue crack growth have shown great dispersancy. Study on stochastic crack growth of material at room temperature has been widely performed. However, probabilistic model for crack growth at fatigue-creep has been little investigated due to the complexity of the deterministic model for crack growth at fatigue-creep as well as the time-consuming and the difficulty of the experiments. Traditional crack measurement such as direct current and alternating current electrical potential technique, compliance method is limited for circuit interference at large crack, especially when the temperature is higher than 500°C. Experimental system to achieve real-time FCCG detection at high temperature is established by introducing a long-distance microscope with high magnification and resolution from distances of 15cm to 35cm. The experimental setup consists of a dynamic testing machine, a machine controller, a temperature controlled box, a long-distance microscope and a high temperature furnace from room temperature to 1000°C. Then the fatigue-creep crack growth (FCCG) rate tests on thirty compact tension (CT) specimens made of GH4133B material at 600°C are carried out. The reason for choosing the GH4133B Ni-based superalloy is owing to its popularity in use for the turbine disc of the aero-engine. The tests are conducted on a 100KN capacity servo-hydraulic closed-loop machine employed trapezoidal load with hold time at upon peak load. Based on the crack growth models used for room temperature, the deterministic model for FCCG rate considering the parameters including temperature, hold time is established through comparison of the analytical results with the experimental data. Then the stochastic FCCG model for GH4133B is proposed and the probability of random to reach a specified crack size can be obtained as well as the distribution function of crack size at the service time. Through comparison between the analytical and experimental results, it’s found that the probabilistic FCCG model can fit the experimental data well. Once the stochastic FCCG model is established, it can be used for the probabilistic damage tolerance design of the turbine components made of GH4133B material.

NEW RESULT OF DIRECT CP VIOLATION IN B → π+π-π+π-

2011 ◽  
Vol 26 (17) ◽  
pp. 2899-2912 ◽  
Author(s):  
GANG LÜ ◽  
ZHEN-HUA ZHANG ◽  
XIU-YING LIU ◽  
LI-YING ZHANG
Keyword(s):  
Experimental Data ◽  
Cp Violation ◽  
Invariant Mass ◽  
Branching Ratios ◽  
Effective Parameter ◽  
Matrix Elements ◽  
Strong Constraint ◽  
Ckm Matrix ◽  
First Order ◽  
Isospin Violation

In the framework of factorization, based on the first-order of isospin violation, we study direct CP violation in the decay of [Formula: see text] including the effect of ρ–ω mixing. The CP violation depends strongly on Cabibbo–Kobayashi–Maskawa (CKM) matrix elements and the effective parameter, Nc. Recently, the experimental data for the branching ratios of [Formula: see text] are accurate and we can give the strong constraint on the range of Nc. We find that the CP violating asymmetry is large and ranges from -82% to -98% via ρ–ω mixing mechanism when the invariant mass of the π+π- pair is in the vicinity of the ω resonance. We also discuss the possibility to observe the predicted CP violating asymmetries at the LHC.

Sivers effect in single spin asymmetry based on the covariant parton model

2017 ◽  
Vol 32 (28n29) ◽  
pp. 1750176
Author(s):  
H. Mahdizadeh Saffar ◽  
A. Mirjalili ◽  
S. Atashbar Tehrani ◽  
M. M. Yazdanpanah
Keyword(s):  
Experimental Data ◽  
Transverse Momentum ◽  
Spin Asymmetry ◽  
Parton Model ◽  
Single Spin Asymmetry ◽  
Unknown Parameters ◽  
Kaon Production ◽  
Single Spin ◽  
Sivers Function ◽  
Global Fit

Sivers effect is describing the correlation between the transverse polarization of nucleon and the transverse momentum, [Formula: see text], of its unpolarized constituent partons. This effect is an outstanding subject and in this regard, a great deal in recent years has been considered from experimental and phenomenological points of view. It also plays an essential role to extend our understanding from nucleon structure. Semi-inclusive DIS (SIDIS) process provides us an opportunity to access to Sivers function which is dependent on transverse momentum of partons. In this paper, for the first time the covariant parton model is used to deliver us the [Formula: see text] and [Formula: see text] dependence part of Sivers function. Based on this model, this combinatory dependence is arising out from the HERAPDF parametrization group. In this paper the other required parametrized functions in Sivers function is also changed with respect to Ref. 1. The unknown parameters which exist in Sivers function can be extracted, doing a global fit over the recent available experimental data, including HERMES, COMPASS and JLAB collaborations for the single spin asymmetry (SSA) in [Formula: see text] and [Formula: see text] meson production as well as kaon production to constrain the evolved strange quark. This is done, considering advanced mathematical manipulations to overcome the difficulties which exist to compute the required multiple integrals and finally employing the CERN MINIUTE program to do a global fit. Our results for SSA are in good agreement with the available experimental data. For more confirmation a comparison between our results and the ones from Ref. 2 is also done.

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