scholarly journals a0(980)–f0(980) mixing in χc1 decay

2019 ◽  
Vol 199 ◽  
pp. 04009
Author(s):  
M Bayar ◽  
V. R. Debastiani
Keyword(s):  
Experimental Measurement ◽  
Isospin Breaking ◽  
Total Amplitude ◽  
Isospin Violation ◽  
Neutral Kaons ◽  
Good Agreement

We investigate the isospin breaking in the ${\chi _{c1}} \to {\pi ^0}{\pi ^ + }{\pi ^ - }$ and ${\chi _{c1}} \to {\pi ^0}{\pi ^0}\eta $ decays and its relation to the a0(980) – f0(980) mixing, which was measured by the BESIII Collaboration. The isospin violation is introduced through the use of different masses for the charged and neutral kaons, either in the propagators of pairs of mesons created in the χc1 decay, or in the propagators inside the T matrix. We find that the most important effect in the total amplitude is the isospin breaking inside the T matrix which is essential to get a good agreement with the experimental measurement of the mixing.

scholarly journals Hadronic vacuum polarization and vector-meson resonance parameters from $$\varvec{e^+e^-\rightarrow \pi ^0\gamma }$$

2020 ◽  
Vol 80 (10) ◽  
Author(s):  
Bai-Long Hoid ◽  
Martin Hoferichter ◽  
Bastian Kubis
Keyword(s):  
Transition Form Factor ◽  
Vacuum Polarization ◽  
Transition Form ◽  
Isospin Breaking ◽  
Meson Resonance ◽  
Resonance Parameters ◽  
Polarization Correction ◽  
Dispersive Representation ◽  
The Masses ◽  
Good Agreement

AbstractWe study the reaction $$e^+e^-\rightarrow \pi ^0\gamma $$ e + e - → π 0 γ based on a dispersive representation of the underlying $$\pi ^0\rightarrow \gamma \gamma ^*$$ π 0 → γ γ ∗ transition form factor. As a first application, we evaluate the contribution of the $$\pi ^0\gamma $$ π 0 γ channel to the hadronic-vacuum-polarization correction to the anomalous magnetic moment of the muon. We find $$a_\mu ^{\pi ^0\gamma }\big |_{\le 1.35\,\text {GeV}}=43.8(6)\times 10^{-11}$$ a μ π 0 γ | ≤ 1.35 GeV = 43.8 ( 6 ) × 10 - 11 , in line with evaluations from the direct integration of the data. Second, our fit determines the resonance parameters of $$\omega $$ ω and $$\phi $$ ϕ . We observe good agreement with the $$e^+e^-\rightarrow 3\pi $$ e + e - → 3 π channel, explaining a previous tension in the $$\omega $$ ω mass between $$\pi ^0\gamma $$ π 0 γ and $$3\pi $$ 3 π by an unphysical phase in the fit function. Combining both channels we find $${\bar{M}}_\omega =782.736(24)\,\text {MeV}$$ M ¯ ω = 782.736 ( 24 ) MeV and $${\bar{M}}_\phi =1019.457(20)\,\text {MeV}$$ M ¯ ϕ = 1019.457 ( 20 ) MeV for the masses including vacuum-polarization corrections. The $$\phi $$ ϕ mass agrees perfectly with the PDG average, which is dominated by determinations from the $${\bar{K}} K$$ K ¯ K channel, demonstrating consistency with $$3\pi $$ 3 π and $$\pi ^0\gamma $$ π 0 γ . For the $$\omega $$ ω mass, our result is consistent but more precise, exacerbating tensions with the $$\omega $$ ω mass extracted via isospin-breaking effects from the $$2\pi $$ 2 π channel.

Numerical Study of the Gas Flow in the Swirl Tube

2012 ◽  
Vol 550-553 ◽  
pp. 3194-3200
Author(s):  
Guang Cai Gao ◽  
Jian Jun Wang ◽  
You Hai Jin
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Reynolds Stress ◽  
Experimental Measurement ◽  
Gas Flow ◽  
Numerical Study ◽  
Separation Performance ◽  
Turbulent Model ◽  
Simulation Results ◽  
Good Agreement

The gas flow field in the swirl tube was studied by experimental measurement and numerical simulation. The results show that the simulation results based on the Reynolds stress turbulent model is in good agreement with the measured results probed by the five orifice Pitot-tube. Meantime, it is analyzed that there is short cut stream at the end of the exit tube, and at the dust discharge jaws, the particles are prone to be re-entrained from the hopper. All results above provide a base for further research on the optimization of the structure and the improvement of the separation performance of the swirl tube.

scholarly journals A phenomenological analysis on isospin-violating decay of X(3872)

2021 ◽  
Vol 81 (2) ◽  
Author(s):  
Qi Wu ◽  
Dian-Yong Chen ◽  
Takayuki Matsuki
Keyword(s):  
Phenomenological Analysis ◽  
Partial Width ◽  
Width Ratio ◽  
Neutral Meson ◽  
Isospin Breaking ◽  
Isospin Violation ◽  
Charm Decay ◽  
Charged Meson ◽  
Coupling Strengths ◽  
Belle Ii

AbstractIn a molecular scenario, we investigate the isospin-breaking hidden charm decay processes of X(3872), i.e., $$X(3872) \rightarrow \pi ^+ \pi ^- J/\psi $$ X ( 3872 ) → π + π - J / ψ , $$X(3872) \rightarrow \pi ^+ \pi ^- \pi ^0 J/\psi $$ X ( 3872 ) → π + π - π 0 J / ψ , and $$X(3872)\rightarrow \pi ^0\chi _{cJ}$$ X ( 3872 ) → π 0 χ cJ . We assume that the source of the strong isospin violation comes from the different coupling strengths of X(3872) to its charged components $$D^{*+} D^-$$ D ∗ + D - and neutral components $$D^{*0 } {\bar{D}}^0$$ D ∗ 0 D ¯ 0 as well as the interference between the charged meson loops and neutral meson loops. The former effect could fix our parameters by using the measurement of the ratio $$\Gamma [X(3872) \rightarrow \pi ^+ \pi ^- \pi ^0 J/\psi ]/\Gamma [X(3872) \rightarrow \pi ^+ \pi ^- J/\psi ]$$ Γ [ X ( 3872 ) → π + π - π 0 J / ψ ] / Γ [ X ( 3872 ) → π + π - J / ψ ] . With the determined parameter range, we find that the estimated ratio $$\Gamma [X(3872) \rightarrow \pi ^0 \chi _{c1}/\Gamma [X(3872) \rightarrow \pi ^+ \pi ^- J/\psi ]$$ Γ [ X ( 3872 ) → π 0 χ c 1 / Γ [ X ( 3872 ) → π + π - J / ψ ] is well consistent with the experimental measurement from the BESIII collaboration. Moreover, the partial width ratio of $$\pi ^0 \chi _{cJ}$$ π 0 χ cJ for $$J=0,1,2$$ J = 0 , 1 , 2 is estimated to be $$1.77{-}1.65:1:1.09{-}1.43$$ 1.77 - 1.65 : 1 : 1.09 - 1.43 , which could be tested by further precise measurements of BESIII and Belle II.

scholarly journals The $$D_s^+ \rightarrow a_0(980) e^+ \nu _e$$ reaction and the $$a_0(980)-f_0(980)$$ mixing

2021 ◽  
Vol 81 (11) ◽  
Author(s):  
Jia-Xin Lin ◽  
Jia-Ting Li ◽  
Sheng-Juan Jiang ◽  
Wei-Hong Liang ◽  
E. Oset
Keyword(s):  
Upper Bound ◽  
Production Mechanism ◽  
Scalar Mesons ◽  
Isospin Violation ◽  
Neutral Kaons ◽  
Scalar Resonances ◽  
Different Sources

AbstractWe perform a study of the $$D_s^+ \rightarrow a_0(980)(f_0(980)) e^+ \nu _e$$ D s + → a 0 ( 980 ) ( f 0 ( 980 ) ) e + ν e reactions investigating the different sources of isospin violation which make the production of the $$a_0(980)$$ a 0 ( 980 ) possible. We find that loops involving kaons in the production mechanism provide a source of isospin violation since they do not cancel due to the different mass of charged and neutral kaons, but we also find that the main source comes from the breaking of isospin in the meson-meson transition T matrices, which contain information on the nature of the low lying scalar mesons. The reaction is thus very sensitive to the nature of the $$a_0(980)$$ a 0 ( 980 ) and $$f_0(980)$$ f 0 ( 980 ) resonances. Our results are consistent with the present upper bound for $$a_0(980)$$ a 0 ( 980 ) production and only a factor three smaller, indicating that future runs with more statistics should find actual numbers for this reaction from where we can learn more about the origin of the scalar resonances and their nature.

A New Experimental Method Allowing a Quantitative Measure of Orthopositronium Magnetic Quenching

1973 ◽  
Vol 51 (21) ◽  
pp. 2270-2274 ◽  
Author(s):  
F. Falciglia ◽  
G. Iaci ◽  
M. Lo Savio ◽  
E. Turrisi
Keyword(s):  
Magnetic Field ◽  
Experimental Method ◽  
Angular Correlation ◽  
Experimental Measurement ◽  
Quantitative Measure ◽  
New Method ◽  
Direct Measure ◽  
Correlation Techniques ◽  
Good Agreement

A new method for determining the amount of magnetic quenching of the orthopositronium atom is described. This method, still using angular correlation techniques, allows a direct measure of the quantities which the orthopositronium magnetic quenching deals with. By this way, an experimental measurement has been performed, as a check, in water at temperature T = 20 °C and with a magnetic field H = 10 kG. The obtained value ΔIs = (1.73 ± 0.22)% is in very good agreement with the theoretical one.

scholarly journals Experimental measurement of the specific mass of drilling fluids at high pressure and high temperature

2019 ◽  
Author(s):  
Vinícius Henrique Boschini ◽  
Paulo Roberto Ribeiro ◽  
Nara Angélica Policarpo ◽  
Nilo Ricardo Kim
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Experimental Measurement ◽  
Drilling Fluids ◽  
Distilled Water ◽  
Constant Composition ◽  
Specific Mass ◽  
Expansion Procedure ◽  
Good Agreement

The knowledge of specific mass of drilling fluids are of great importance in defining the characteristics of them during drilling wells. In the present work, the specific mass of distilled water was carried out in a PVT (Pressure-Volume-Temperature) cell using the Constant Composition Expansion procedure under high pressure and high temperature. Results showed a good agreement with literature valures.

Experimental Measurement of Resonance Frequencies of Asymmetric Micro-bridge Resonators

2011 ◽  
Vol 22 (2) ◽  
pp. 127-136 ◽  
Author(s):  
Pezhman A. Hassanpour ◽  
William L. Cleghorn ◽  
Ebrahim Esmailzadeh ◽  
James K. Mills
Keyword(s):  
Analytical Model ◽  
Experimental Measurement ◽  
Natural Frequencies ◽  
Resonance Frequencies ◽  
Comb Drives ◽  
Second Mode ◽  
Novel Design ◽  
Good Agreement

The experiment results on the resonance frequencies of micro-bridge resonators with attached electrostatic comb-drives are reported in this article. The resonators include a novel design of asymmetric resonators, in which the comb-drives are attached to off-midpoint of the beam. The experiment results confirm that by properly designing the location and mass of the comb-drives, the natural frequencies can exceed those of conventional symmetric resonators. Moreover, it has been shown that the second mode of vibration of asymmetric resonators, in contrast to that of symmetric resonators, can be excited, hence exploited for applications in which multiple working frequencies are desired. The experiment results are in good agreement with the analytical model. The deviations between these two are discussed in detail.

scholarly journals Modeling of Non-Linear and Hysteretic Magnetization Effects in Transient Potential Drop Measurements

2020 ◽  
Author(s):  
Øyvind Persvik ◽  
Zhiliang Zhang
Keyword(s):  
Finite Difference ◽  
Experimental Measurement ◽  
Applied Field ◽  
Quadratic Function ◽  
Potential Drop ◽  
Rayleigh Law ◽  
Non Linear ◽  
Ferromagnetic Steel ◽  
Good Agreement

We have compared transient potential drop measurements on ferromagnetic steel rods with finite difference simulation assuming that the magnetization varies as a quadratic function of the applied field. Good agreement between simulation and experimental measurement is achieved and the results are discussed in terms of the Rayleigh law of magnetization.

scholarly journals High Potential of Magnet on the Performance of Dual Piezoelectric Fans in Electronics Cooling System

2018 ◽  
Vol 10 (2) ◽  
pp. 469 ◽  
Author(s):  
Abdul Razak Fadhilah ◽  
Robiah Ahmad ◽  
Sarip Shamsul
Keyword(s):  
Heat Transfer ◽  
Magnetic Force ◽  
Cooling System ◽  
Electronics Cooling ◽  
Total Amplitude ◽  
System A ◽  
Cooling Method ◽  
Optimization Parameters ◽  
Better Than ◽  
Good Agreement

Recently, piezoelectric fan has gained attention as potential active cooling method for electronics devices. Even though the piezoelectric requires high voltage, there are findings to overcome the shortcomings. Adding on a magnet at the tip of the piezoelectric fan to activate other magnetic passive fans is one of the methods to increase the total amplitude generated by the fans. This paper will discuss on the performance of integrated piezoelectric fan with passive fans (later refer to magnetic fans) to enhance the heat transfer in cooling system. A repulsive force produced by the magnets will cause the magnetic blades to oscillate together with the piezoelectric fan. The paper will focus on the optimization parameters of the magnets for selected dimension of piezoelectric fan. The parameters under investigation are the position of the magnet on the piezoelectric fan, number of magnets on each blades and orientation of blades with respect to adjacent blade. Results show that the magnet at middle location of extensive blade with double magnets generate the largest amplitude, 80% better than fan without magnet and for dual integrated piezoelectric fan with magnetic fan, radial orientation gives better result by 25%. By increasing the total amplitude using magnetic force, power consumption can be reduced while the heat transfer performance can be enhanced. it shows a good agreement for positive heat transfer and thermal resistance improvement compared to natural convection.

Natural Convection of a Heat Generating Fluid in a Closed Vertical Cylinder: An Examination of Theoretical Predictions

1971 ◽  
Vol 13 (3) ◽  
pp. 151-156 ◽  
Author(s):  
A. Watson
Keyword(s):  
Experimental Data ◽  
Natural Convection ◽  
Boundary Conditions ◽  
Experimental Measurement ◽  
Analytical Method ◽  
Vertical Cylinder ◽  
Thermal Boundary Conditions ◽  
Integral Technique ◽  
Theoretical Predictions ◽  
Good Agreement

An analysis of the natural convection of a heat generating fluid in a semi-infinite vertical cylinder has been seen, in a previous publication, to give good agreement with experimental measurement. The analytical method used was that of solving the integrated equations of continuity, motion and energy, a technique which is frequently applied to internal natural convection problems and which has a reputation for being insensitive to thermal boundary conditions and the profile assumptions needed. The boundary conditions assumed for the analysis were not those of the experiment, and this paper is the result of an examination of the sensitivity of the prediction to the assumed conditions. A new analysis has been carried out with the boundary conditions of the experiment, and with profile assumptions closer to the experimental data. The new predictions show much less favourable agreement. It is concluded that the agreement obtained in the earlier analysis should not be used as a recommendation of the integral technique.

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