scholarly journals Scalar form factor of the proton with light-cone QCD sum rules

2006 ◽  
Vol 73 (9) ◽  
Author(s):  
Zhi-Gang Wang ◽  
Shao-Long Wan ◽  
Wei-Min Yang
Keyword(s):  
Form Factor ◽  
Light Cone ◽  
Sum Rules ◽  
Scalar Form Factor ◽  
Qcd Sum Rules ◽  
Scalar Form

scholarly journals ELECTROMAGNETIC FORM-FACTOR OF THE π MESON WITH LIGHT-CONE QCD SUM RULES

2008 ◽  
Vol 23 (27n28) ◽  
pp. 4621-4636 ◽  
Author(s):  
ZHI-GANG WANG ◽  
ZHI-BIN WANG
Keyword(s):  
Experimental Data ◽  
Form Factor ◽  
Momentum Transfer ◽  
Electromagnetic Form Factor ◽  
Light Cone ◽  
Sum Rules ◽  
Large Momentum ◽  
Normalization Condition ◽  
Qcd Sum Rules ◽  
Zero Momentum

In this paper, we calculate the electromagnetic form-factor of the π meson with the light-cone QCD sum rules. The numerical value [Formula: see text] is in excellent agreement with the experimental data (extrapolated to the limit of zero momentum transfer or the normalization condition Fπ(0) = 1). For large momentum transfers, the values from the two sum rules are all comparable with the experimental data and theoretical estimations.

scholarly journals PION TRANSITION FORM FACTOR AT THE TWO-LOOP LEVEL VIS-À-VIS EXPERIMENTAL DATA

2009 ◽  
Vol 24 (35n37) ◽  
pp. 2858-2867 ◽  
Author(s):  
S. V. MIKHAILOV ◽  
N. G. STEFANIS
Keyword(s):  
Experimental Data ◽  
Perturbation Theory ◽  
Form Factor ◽  
Light Cone ◽  
Transition Form Factor ◽  
Sum Rules ◽  
Leading Order ◽  
Transition Form ◽  
Qcd Sum Rules ◽  
Theoretical Results

We use light-cone QCD sum rules to calculate the pion-photon transition form factor, taking into account radiative corrections up to the next-to-next-to-leading order of perturbation theory. We compare the obtained predictions with all available experimental data from the CELLO, CLEO, and the BaBar Collaborations. We point out that the BaBar data are incompatible with the convolution scheme of QCD, on which our predictions are based, and can possibly be explained only with a violation of the factorization theorem. We pull together recent theoretical results and comment on their significance.

scholarly journals Soft contribution to the pion form factor from light-cone QCD sum rules

1994 ◽  
Vol 328 (3-4) ◽  
pp. 457-465 ◽  
Author(s):  
Vladimir Braun ◽  
Igor Halperin
Keyword(s):  
Form Factor ◽  
Light Cone ◽  
Sum Rules ◽  
Pion Form Factor ◽  
Qcd Sum Rules

scholarly journals The $$ \overline{B} $$ → π form factors from QCD and their impact on |Vub|

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Domagoj Leljak ◽  
Blaženka Melić ◽  
Danny van Dyk
Keyword(s):  
Form Factor ◽  
Lattice Qcd ◽  
Sum Rules ◽  
Semileptonic Decay ◽  
Form Factors ◽  
Scalar Form Factor ◽  
Small Momentum Transfer ◽  
Scalar Form ◽  
Sum Rule ◽  
First Time

Abstract We revisit light-cone sum rules with pion distribution amplitudes to determine the full set of local $$ \overline{B} $$ B ¯ → π form factors. To this end, we determine all duality threshold parameters from a Bayesian fit for the first time. Our results, obtained at small momentum transfer q2, are extrapolated to large q2 where they agree with precise lattice QCD results. We find that a modification to the commonly used BCL parametrization is crucial to interpolate the scalar form factor between the two q2 regions. We provide numerical results for the form factor parameters — including their covariance — based on simultaneous fit of all three form factors to both the sum rule and lattice QCD results. Our predictions for the form factors agree well with measurements of the q2 spectrum of the semileptonic decay $$ {\overline{B}}^0\to {\pi}^{+}{\mathrm{\ell}}^{-}{\overline{\nu}}_{\mathrm{\ell}} $$ B ¯ 0 → π + ℓ − ν ¯ ℓ . From the world average of the latter we obtain |Vub| = (3.77 ± 0.15) · 10−3, which is in agreement with the most recent inclusive determination at the 1 σ level.

scholarly journals The Radiative Δ(1600) → γN Decay in the Light-Cone QCD Sum Rules

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 255
Author(s):  
Haifa I. Alrebdi ◽  
Thabit Barakat
Keyword(s):  
Decay Rate ◽  
Light Cone ◽  
Magnetic Dipole Moment ◽  
Sum Rules ◽  
Electric Quadrupole ◽  
The Other ◽  
Electric Quadrupole Moment ◽  
Multipole Moments ◽  
Qcd Sum Rules ◽  
Strongly Agree

Within the framework of the light-cone QCD sum rules method (LCSR’s), the radiative Δ(1600)→γN decay is studied. In particular, the magnetic dipole moment GM1(0) and the electric quadrupole moment GE1(0) are estimated. We also calculate the ratio REM=−GE1(0)GM1(0) and the decay rate. The predicted multipole moments and the decay rate strongly agree with the existing experimental results as well as with the other available phenomenological approaches.

scholarly journals ANALYSIS OF THE $B \to K^*_2(1430), a_2(1320), f_2(1270)$ FORM-FACTORS WITH LIGHT-CONE QCD SUM RULES

2011 ◽  
Vol 26 (37) ◽  
pp. 2761-2782 ◽  
Author(s):  
ZHI-GANG WANG
Keyword(s):  
Experimental Data ◽  
Light Cone ◽  
B Meson ◽  
Sum Rules ◽  
Form Factors ◽  
Distribution Amplitude ◽  
Qcd Sum Rules ◽  
Line Shapes ◽  
The Future

In this paper, we study the [Formula: see text] form-factors with the light-cone QCD sum rules, where the B-meson light-cone distribution amplitudes are used. In calculations, we observe that the line-shapes of the B-meson light-cone distribution amplitude ϕ+(ω) have significant impacts on the values of the form-factors, and expect to obtain severe constraints on the parameters of the B-meson light-cone distribution amplitudes from the experimental data in the future.

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