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Guohuai Zhu

Publications and source records attributed to Guohuai Zhu.

42 records · Page 3Linked to original sources
arXiv2001

QCD factorization for B -> PP

In this work, we give a detailed discussion for QCD factorization involved the complete chirally enhanced power corrections for B decays to two light pseudoscalar mesons, and present some detailed calculations of radiative corrections at the order of alpha_s. We point out that the infrared finiteness of the vertex corrections in the chirally enhanced power corrections requires twist-3 light-cone distribution amplitudes (LCDAs) of the light pseudoscalar symmetric. However, even in the symmetric condition, there is also logarithmic divergence from the endpoints of the twist-3 LCDAs in the hard spectator scattering. We point out that the decay amplitudes of B --> PP predicted by QCD factorization are really free of the renormalization scale dependence, at least at the order of alpha_s. At last, we briefly compare the QCD factorization with the generalized factorization and PQCD method.

hep-ph↗
arXiv2001

Infrared Divergence and Twist-3 Distribution Amplitudes in QCD Factorization For $B \to PP$

Since b quark mass is not asymptotically large, chirally enhanced corrections which arise from twist-3 wave functions may be important in B decays. We thus evaluate the hadronic matrix elements with the final light pseudoscalar mesons described by leading twist and twist-3 distribution amplitudes. We find that chirally enhanced corrections can be included consistently in the framework of QCD factorization only if the twist-3 distribution amplitudes are symmetric. We then give explicit expressions of $a_i^p$ for $B \to ππ$ at the next-to-leading order of $α_s$ including chirally enhanced corrections. We also briefly discuss the divergence appeared in the hard spectator contributions.

hep-ph↗
arXiv2000

QCD Factorization For B Decays To Two Light Pseudoscalars Including Chirally Enhanced Corrections

Since b quark mass is not asymptotically large, chirally enhanced corrections which arise from twist-3 wave functions may be important in B decays. We thus evaluate the hadronic matrix elements with the emitted meson described by leading twist and twist-3 distribution amplitudes $Φ_p(x)$. After summing over the four "vertex correction" diagrams, we obtain the results with infrared finiteness which shows that chirally enhanced corrections arise from $Φ_p(x)$ can be consistently included in QCD factorization. We also briefly discuss the contributions from "hard spectator" diagrams.

hep-ph↗
arXiv1999

Further Analysis of Di-gluon Fusion Mechanism for the decays of $B \to K η^{\prime}$

Di-gluon fusion mechanism might account for the large branching ratios of $B\to K η^{\prime}$. But because we know little about the effective $η^{\prime}gg$ vertex, there are large uncertainties in perturbative QCD estimations. In this paper, we try several kinds of $η^{\prime}gg$ form factors and compare the numerical results with the experiment. We find that, though we know little about $η^{\prime}gg$ form factor, if di-gluon fusion mechanism is important in $B\to K η^{\prime}$, the branching ratios of the decays $B\to K^{\ast} η^{\prime}$ would be around $10^{-5}$ which can be tested by future experiments.

hep-ph↗
arXiv1999

Nonleptonic charmless 2-body B decays in the perturbative QCD approach

With the generalized factorization approximation, we calculate the branching ratios and CP asymmetries in B meson decays into two charmless pseudoscalar mesons. We give a new estimation of the matrix elements of (S+P)(S-P) current products with the PQCD method instead of equation of motion. We find that our results are comparatively smaller than those in the literature.

hep-ph↗
arXiv1998

Further Analysis of $B \to η^{\prime} K(K^*),ηK(K^*)$ Processes

Combining three mechanisms, we reanalysis processes of $B \to η^{\prime} K(K^*),ηK(K^*)$ and calculate their branching ratios. The results are compared with other mechanisms in the literature. The striking feature of the gluon fusion mechanism is emphasized and its experimental test is discussed.

hep-ph↗