scholarly journals QCD sum rules analysis of weak decays of doubly heavy baryons: the $$b\rightarrow c$$ processes

2021 ◽  
Vol 81 (12) ◽  
Author(s):  
Zhi-Peng Xing ◽  
Zhen-Xing Zhao
Keyword(s):  
Correlation Functions ◽  
Sum Rules ◽  
Form Factors ◽  
Final States ◽  
Qcd Sum Rules ◽  
Leptonic Decays ◽  
Weak Decays ◽  
Heavy Baryons ◽  
Point Correlation ◽  
Comprehensive Study

AbstractA comprehensive study of $$b\rightarrow c$$ b → c weak decays of doubly heavy baryons is presented in this paper. The transition form factors as well as the pole residues of the initial and final states are respectively obtained by investigating the three-point and two-point correlation functions in QCD sum rules. Contributions from up to dimension-6 operators are respectively considered for the two-point and three-point correlation functions. The obtained form factors are then applied to a phenomenological analysis of semi-leptonic decays.

J/ψ COUPLINGS TO OPEN CHARM MESONS FROM QCD SUM RULES

2005 ◽  
Vol 14 (04) ◽  
pp. 555-567 ◽  
Author(s):  
R. D. MATHEUS ◽  
F. S. NAVARRA ◽  
M. NIELSEN ◽  
R. RODRIGUES DA SILVA
Keyword(s):  
Correlation Functions ◽  
Constituent Quark ◽  
Sum Rules ◽  
Form Factors ◽  
Constituent Quark Model ◽  
Coupling Constants ◽  
Momentum Dependence ◽  
Charm Mesons ◽  
Qcd Sum Rules ◽  
Point Correlation

We employ QCD sum rules to calculate the J/ψ form factors and coupling constants with charmed mesons, by studying three-point correlation functions. In particular, we consider the J/ψD*D and J/ψDD vertices. We determine the momentum dependence of the form factors for kinematical conditions where J/ψ, D or D* are off-shell. Extrapolating to the pole of each of the form factors obtained, we determine the coupling constants. For both couplings, our results (within the errors) are compatible with estimates based on the constituent quark model.

scholarly journals Analysis of the strong vertices of Σc∗ND and Σb∗NB in QCD sum rules

2017 ◽  
Vol 32 (35) ◽  
pp. 1750203 ◽  
Author(s):  
Guo-Liang Yu ◽  
Zhi-Gang Wang ◽  
Zhen-Yu Li
Keyword(s):  
Strong Coupling ◽  
Sum Rules ◽  
Form Factors ◽  
Coupling Constants ◽  
Strong Interactions ◽  
Dirac Structure ◽  
Qcd Sum Rules ◽  
Analytical Functions ◽  
Heavy Baryons ◽  
Perturbative Part

The strong coupling constants not only are important to understand the strong interactions of the heavy baryons, but can also help us reveal the nature and structure of these baryons. Additionally, researchers indeed have made great efforts to calculate some of the strong coupling constants, [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], etc. In this paper, we analyze the strong vertices [Formula: see text] and [Formula: see text] using the three-point QCD sum rules under the Dirac structure of [Formula: see text]. We perform our analysis by considering the contributions of the perturbative part and the condensate terms of [Formula: see text] and [Formula: see text]. After the form factors are calculated, they are then fitted into analytical functions which are used to get the strong coupling constants for these two vertices. The final results are [Formula: see text] and [Formula: see text].

scholarly journals The scalar and pseudoscalar hidden-charm tetraquark states with QCD sum rules

2018 ◽  
Vol 33 (14n15) ◽  
pp. 1850090
Author(s):  
Zun-Yan Di ◽  
Zhi-Gang Wang
Keyword(s):  
Experimental Data ◽  
Correlation Functions ◽  
Sum Rules ◽  
Qcd Sum Rules ◽  
Sum Rule ◽  
Rule Approach ◽  
Point Correlation ◽  
The Masses ◽  
Vacuum Condensates ◽  
Conserved Currents

Based on the diquark configuration, we construct the diquark–antidiquark interpolating tetraquark currents with [Formula: see text] and [Formula: see text], which can couple to the scalar and pseudoscalar tetraquark states, respectively, since they are not conserved currents. Then, we investigate their two-point correlation functions including the contributions of the vacuum condensates up to dimension-10 and extract the masses and pole residues of the tetraquark states with [Formula: see text] and [Formula: see text] through the QCD sum rule approach. The predicted masses can be confronted with the experimental data in the future. Moreover, we briefly discuss the possible decay patterns of the tetraquark states.

scholarly journals Light-by-light forward scattering amplitudes in Lattice QCD

2018 ◽  
Vol 175 ◽  
pp. 06030
Author(s):  
Antoine Gérardin ◽  
Jeremy Green ◽  
Oleksii Gryniuk ◽  
Georg von Hippel ◽  
Harvey B. Meyer ◽  
...  
Keyword(s):  
Scattering Amplitudes ◽  
Lattice Qcd ◽  
Cross Sections ◽  
Correlation Functions ◽  
Sum Rules ◽  
Form Factors ◽  
Forward Scattering ◽  
Meson Pole ◽  
Point Correlation ◽  
Dispersive Approach

We present our preliminary results on the calculation of hadronic light-by-light forward scattering amplitudes using vector four-point correlation functions computed on the lattice. Using a dispersive approach, forward scattering amplitudes can be described by γ*γ* → hadrons fusion cross sections and then compared with phenomenology. We show that only a few states are needed to reproduce our data. In particular, the sum rules considered in this study imply relations between meson–γγ couplings and provide valuable information about individual form factors which are often used to estimate the meson-pole contributions to the hadronic light-by-light contribution to the (g – 2) of the muon.

scholarly journals The transition form factors for semi-leptonic weak decays of J/ψ in QCD sum rules

2008 ◽  
Vol 54 (1) ◽  
pp. 107-121 ◽  
Author(s):  
Yu-Ming Wang ◽  
Hao Zou ◽  
Zheng-Tao Wei ◽  
Xue-Qian Li ◽  
Cai-Dian Lü
Keyword(s):  
Sum Rules ◽  
Form Factors ◽  
Transition Form ◽  
Qcd Sum Rules ◽  
Weak Decays

scholarly journals The semi-leptonic form factors of $$\Lambda _{b}\rightarrow \Lambda _{c}$$ and $$\Xi _{b}\rightarrow \Xi _{c}$$ in QCD sum rules

2020 ◽  
Vol 80 (12) ◽  
Author(s):  
Zhen-Xing Zhao ◽  
Run-Hui Li ◽  
Yue-Long Shen ◽  
Yu-Ji Shi ◽  
Yan-Sheng Yang
Keyword(s):  
Correlation Function ◽  
Lattice Qcd ◽  
Sum Rules ◽  
Form Factors ◽  
Leading Order ◽  
Qcd Sum Rules ◽  
Point Correlation ◽  
Point Correlation Function

AbstractIn this work, the full leading order results of the form factors for $$\Xi _{b}\rightarrow \Xi _{c}$$ Ξ b → Ξ c and $$\Lambda _{b}\rightarrow \Lambda _{c}$$ Λ b → Λ c are obtained in QCD sum rules. Contributions from up to dimension-5 have been considered. For completeness, we also study the two-point correlation function to obtain the pole residues of $$\Xi _{Q}$$ Ξ Q and $$\Lambda _{Q}$$ Λ Q , and higher accuracy is achieved. For the three-point correlation function, since stable Borel regions cannot be found, about $$20\%$$ 20 % uncertainties are introduced for the form factors of $$\Xi _{b}\rightarrow \Xi _{c}$$ Ξ b → Ξ c and $$\Lambda _{b}\rightarrow \Lambda _{c}$$ Λ b → Λ c . Our results for the form factors are consistent with those of the lattice QCD within errors.

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.

scholarly journals Analysis of the strong coupling form factors of Σ b NB and Σ c ND in QCD sum rules

2017 ◽  
Vol 41 (8) ◽  
pp. 083104 ◽  
Author(s):  
Guo-Liang Yu ◽  
Zhi-Gang Wang ◽  
Zhen-Yu Li
Keyword(s):  
Strong Coupling ◽  
Sum Rules ◽  
Form Factors ◽  
Qcd Sum Rules
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