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Ming-Qiu Huang

Publications and source records attributed to Ming-Qiu Huang.

At least 55 records · Page 3Linked to original sources

Light-cone Distribution Amplitudes of Xi and their Applications

We present the light-cone distribution amplitudes of the Xi baryons up to twist six on the basis of QCD conformal partial wave expansion to the leading order conformal spin accuracy. The nonperturbative parameters relevant to the DAs are determined in the framework of the QCD sum rule. The light-cone QCD sum rule approach is used to investigate both the electromagnetic form factors of Xi and the exclusive semileptonic decay of Xi_c as applications. Our estimations on the magnetic moments are $μ_{Ξ^0}=-(1.92\pm0.34)μ_N$ and $μ_{Ξ^-}=-(1.19\pm0.03)μ_N$. The decay width of the process Xi_c->Xi e^+ν_e is evaluated to be $Γ=8.73\times10^{-14}{GeV}$, which is in accordance with the experimental measurements and other theoretical approaches.

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$(Q\bar{s})^{(*)}(\bar{Q}s)^{(*)}$ molecular states from QCD sum rules: a view on Y(4140)

Masses for the $(Q\bar{s})^{(*)}(\bar{Q}s)^{(*)}$ ($Q=c$ or $b$) molecular states are systematically computed in the framework of QCD sum rules. Technically, contributions of the operators up to dimension six are included in operator product expansion (OPE). The numerical result $4.13\pm0.10 {GeV}$ for $D_{s}^{*}\bar{D}_{s}^{*}$ agrees well with the mass $4143.0\pm2.9\pm1.2 {MeV}$ for Y(4140), which supports the $D_{s}^{*}\bar{D}_{s}^{*}$ molecular configuration for Y(4140).

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Semileptonic $B$ Meson Decays Into A Highly Excited Charmed Meson Doublet

We study the heavy quark effective theory prediction for semileptonic $B$ decays into an orbital excited $F$-wave charmed doublet, the ($2^{+}$, $3^{+}$) states ($D^{*'}_{2}$, $D_{3}$), at the leading order of heavy quark expansion. The corresponding universal form factor is estimated by using the QCD sum rule method. The decay rates we predict are $Γ_{B\to D^{*'}_{2}\ell\overlineν}=1.85\times10^{-19} {GeV}$ and $Γ_{B\to D_{3}\ell\overlineν}=1.78\times10^{-19} {GeV}$. The branching ratios are $\mathcal {B}(B\to D_{2}^{*'}\ell\overlineν)=4.6\times10^{-7}$ and $\mathcal {B}(B\to D_{3}\ell\overlineν)=4.4\times10^{-7}$, respectively.

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Electromagnetic form factors of the $Λ$ and $Σ$ baryons in an alternative baryonic current approach

Light-cone sum rules are used to investigate the electromagnetic form factors of the $Λ$ and $Σ$ baryons by using the Ioffe type interpolating currents. The sum rules are affected to some extent by the choice of the interpolating currents from a comparison. Numerical calculations show that the magnetic form factor can be well fitted by the dipole formula for $Σ$ but not for $Λ$. The magnetic form factor of $Λ$ approaches zero with the momentum transfer faster than the dipole formula estimation.

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Light-cone QCD Sum Rules for the $Λ$ Baryon Electromagnetic Form Factors and its magnetic moment

We present the light-cone QCD sum rules up to twist 6 for the electromagnetic form factors of the $Λ$ baryon. To estimate the magnetic moment of the baryon, the magnetic form factor is fitted by the dipole formula. The numerical value of our estimation is $μ_Λ=-(0.64\pm0.04)μ_N$, which is in accordance with the experimental data and the existing theoretical results. We find that it is twist 4 but not the leading twist distribution amplitudes that dominate the results.

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Distribution amplitudes of $Σ$ and $Λ$ and their electromagnetic form factors

Based on QCD conformal partial wave expansion to leading order conformal spin accuracy, we present the light-cone distribution amplitudes (DAs) of $Σ$ and $Λ$ baryons up to twist 6. It is concluded that fourteen ndependent DAs are needed to describe the valence three-quark states of the baryons at small transverse separations. The nonperturbative parameters relevant to the DAs are determined within the framework of QCD sum rule method. With the obtained DAs, a simple investigation on the electromagnetic form factors of these baryons are given. The magnetic moments of the baryons are estimated by fitting the magnetic form factor with the dipole formula.

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Semileptonic Decays of B Meson Transition Into D-wave Charmed Meson Doublets

We use QCD sum rules to estimate the leading-order universal form factors describing the semileptonic B decay into orbital excited $D$-wave charmed doublets, including the ($1^{-}$, $2^{-}$) states ($D_{1}^{*}$, $D'_{2}$) and the ($2^{-}$, $3^{-}$) states ($D_{2}$, $D_{3}^{*}$). The decay rates we predict are $Γ_{B\to D^{*}_{1}\ell\overlineν}=Γ_{B\to D'_{2}\ell\overlineν}=2.4\times10^{-18} {GeV}$, $Γ_{B\to D_{2}\ell\overlineν}=6.2\times10^{-17} {GeV}$, and $Γ_{B\to D_{3}^{*}\ell\overlineν}=8.6\times10^{-17} {GeV}$. The branching ratios are $\mathcal {B}(B\to D^{*}_{1}\ell\overlineν)=\mathcal {B}(B\to D'_{2}\ell\overlineν)=6.0\times10^{-6}$, $\mathcal {B}(B\to D_{2}\ell\overlineν)=1.5\times10^{-4}$, and $\mathcal {B}(B\to D_{3}^{*}\ell\overlineν)=2.1\times10^{-4}$, respectively.

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Deciphering triply heavy baryons in terms of QCD sum rules

The mass spectra of ground-state triply heavy baryons are systematically unscrambled and computed in QCD sum rules. With a tentative $(QQ)-(Q')$ configuration for $QQQ'$, the interpolating currents representing the triply heavy baryons are proposed. Technically, contributions of the operators up to dimension six are included in operator product expansion (OPE). The numerical results are presented in comparison with other theoretical predictions.

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Heavy baryon spectroscopy in QCD

We perform a systematic study of the masses of charmed and bottom baryons in the framework of the QCD sum rule approach. Contributions of the operators up to dimension six are included in operator product expansion. The resulting heavy baryon masses from the calculations are well consistent with the experimental values, and predictions to the spectroscopy of the unobserved bottom baryons are also presented.

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Doubly heavy baryons in QCD sum rules

The mass spectra of doubly heavy baryons are systematically calculated in the framework of QCD sum rules. With a tentative heavy-diquark--light-quark configuration, the interpolating currents representing the doubly heavy baryons are proposed. Contributions of the operators up to dimension six are included in operator product expansion. The numerical results are compatible with other theoretical predictions, which may support the $(QQ)-(q)$ structure of doubly heavy baryons.

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Mass spectra of the heavy baryons Lambda_Q and Sigma_Q^(*) from QCD sum rules

We use QCD sum rule approach to calculate the masses of the ground-state Lambda_Q and Sigma_Q^(*) baryons. Contributions of the operators up to dimension six are included in operator product expansion. The resulting heavy baryonic masses from the calculations are m_{Lambda_b}=5.69 +/- 0.13 GeV, and m_{Lambda_c}=2.31 +/- 0.19 GeV for Lambda_Q; m_{Sigma_b}=5.73 +/- 0.21 GeV, m_{Sigma_b^*}=5.81 +/- 0.19 GeV, m_{Sigma_c}=2.40 +/- 0.31 GeV and m_{Sigma_c^*}=2.56 +/- 0.24 GeV for Sigma_Q^(*), respectively, which are in good agreement with the experimental values.

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Semileptonic decay Lambda_c-->Lambda \ell^+ νfrom QCD light-cone sum rules

We present the study of the semileptonic decay Λ_c to Λ\ell^+νby using the light-cone sum rule approach. Distribution amplitudes (DAs) for the Λbaryon are discussed to the leading order conformal spin, and QCD sum rule estimate for the corresponding parameters is presented. The form factors describing the decay are calculated and used to predict the decay width and the decay asymmetry parameter α. With the inclusion of twist-3 contributions the calculated decay width Γ=(7.2+/-2.0)X10^{-14} GeV as well as asymmetry α=-(0.88+/-0.03) is found in good agreement with the experimental data, while there are appreciable deviations from experiment values when the higher twist contributions are included.

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Note on the Slope Parameter of the Baryonic Λ_b to Λ_c Isgur-Wise Function

Using the framework of the Heavy Quark Effective Theory we have re-analyzed the Isgur-Wise function describing semileptonic Λ_b to Λ_c decays in the QCD sum rule approach. The slope parameter of the Isgur-Wise function is found to be ρ^2 = 1.35 \pm 0.12, which is consistent with an experimental measurement and a lattice calculation. To O(1/m_b,1/m_c) of the heavy quark expansion the integrated Λ_b decay width is used to extract the CKM matrix element V_{cb} for which we obtain a value of |V_{cb}| = 0.041 \pm 0.004 in excellent agreement with the value of |V_{cb}| determined from semileptonic B to D^* decays.

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Exclusive semileptonic B_s decays to excited D_s mesons: Search of D_{sJ}(2317) and D_{sJ}(2460)

We study the exclusive semileptonic decays B_s->D_{s0}^*\ell\barνand B_s->D_{s1}^*\ell\barν, where p-wave excited D_{s0}^* and D_{s1}^* states are identified with the newly observed D_{sJ}(2317) and D_{sJ}(2460) states. Within the framework of HQET the Isgur-Wise functions up to the subleading order of the heavy quark expansion are calculated by QCD sum rules. The decay rates and branching ratios are computed with the inclusion of the order of 1/m_Q corrections. We point out that the investigation of the B_s semileptonic decays to excited D_s mesons may provide some information about the nature of the new D_{sJ}^* mesons.

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Light-cone QCD sum rules for the semileptonic decay Lambda_b --> p lepton anti-neutrino

The exclusive semileptonic heavy baryon decay Λ_b\to p l\barνis investigated using light-cone sum rule method in both full QCD and HQET. The form factors describing the decay are calculated and used to predict the decay width and differential distribution. The total decay width obtained from full QCD is in agreement with the previous theoretical predictions while the HQET result are typically one order smaller. Both results are consistent with the experimental upper limit and can be compared to the refined experimental data in the future.

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Excited heavy baryon masses to order Lambda_{QCD}/m_Q from QCD sum rules

Masses of the p-wave excited heavy baryons have been calculated to the Lambda_{QCD}/m_Q order using QCD sum rule method within the framework of heavy quark effective theory. Numerical results for kinetic energy lambda_1 and chromo-magnetic interaction lambda_2 are presented. The splitting between spin 1/2 and 3/2 doublet derived from our calculation is given, for which the agreement with the current experiment is desirable.

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Choice of heavy baryon currents in QCD sum rules

In this paper we investigate the effects due to the mixing of two interpolating currents for ground state baryons within the framework of Heavy Quark Effective Theory using the QCD sum rule approach. Both two-point and three-point sum rules, thus the mass, coupling constant and Isgur-Wise function sum rules are considered. It is interesting to contrast those results with each other. Based on the Isgur-Wise functions obtained in this paper, we also analyze the effects of current mixing to Lambda-type and and Sigma-type semi-leptonic decays Lambda_b-->Lambda_c\ell\barν, Σ_b-->Σ_c\ell\barνand Σ_b-->Σ^*_c\ell\barν. Decay widths corresponding to various mixing parameters are obtained and can be compared to the experimental data.

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