scholarly journals Transition form factors ofBdecays intop-wave axial-vector mesons in the perturbative QCD approach

2009 ◽  
Vol 79 (3) ◽  
Author(s):  
Run-Hui Li ◽  
Cai-Dian Lü ◽  
Wei Wang
Keyword(s):  
Perturbative Qcd ◽  
Axial Vector ◽  
Form Factors ◽  
Transition Form ◽  
Vector Mesons

scholarly journals D → a1, f1 transition form factors and semileptonic decays via 3-point QCD sum rules

2016 ◽  
Vol 31 (20n21) ◽  
pp. 1650116 ◽  
Author(s):  
Yabing Zuo ◽  
Yue Hu ◽  
Linlin He ◽  
Wei Yang ◽  
Yan Chen ◽  
...  
Keyword(s):  
Sum Rules ◽  
Axial Vector ◽  
Form Factors ◽  
Semileptonic Decays ◽  
Branching Ratios ◽  
Transition Form ◽  
Vector Mesons ◽  
Qcd Sum Rules ◽  
The Future ◽  
Spin Triplet

By using the 3-point QCD sum rules, we calculate the transition form factors of [Formula: see text] decays into the spin triplet axial vector mesons [Formula: see text], [Formula: see text], [Formula: see text]. In the calculations, we consider the quark contents of each meson in detail. In view of the fact that the isospin of [Formula: see text] is one, we calculate the [Formula: see text] and [Formula: see text] transition form factors separately. In the case of [Formula: see text], [Formula: see text], the mixing between light flavor [Formula: see text] singlet and octet is taken into account. Based on the form factors obtained here, we give predictions for the branching ratios of relevant semileptonic decays, which can be tested in the future experiments.

scholarly journals ANALYSIS OF THE $B_q\to D_q(D_q^*)P$ AND $B_q\to D_q(D_q^*)V$ DECAYS WITHIN THE FACTORIZATION APPROACH IN QCD

2009 ◽  
Vol 24 (31) ◽  
pp. 5845-5860 ◽  
Author(s):  
K. AZIZI ◽  
R. KHOSRAVI ◽  
F. FALAHATI
Keyword(s):  
Experimental Data ◽  
Perturbative Qcd ◽  
Sum Rules ◽  
Branching Fraction ◽  
Form Factors ◽  
Transition Form ◽  
Qcd Sum Rules ◽  
Factorization Approach ◽  
Electroweak Penguin ◽  
Decay Widths

Using the factorization approach and considering the contributions of the current–current, QCD penguin and electroweak penguin operators at the leading approximation, the decay amplitudes and decay widths of [Formula: see text] and [Formula: see text] transitions, where q = u, d, s and P and V are pseudoscalar and vector mesons, are calculated in terms of the transition form factors of the Bq→Dq and [Formula: see text]. Having computed those form factors in three-point QCD sum rules, the branching fraction for these decays are also evaluated. A comparison of our results with the predictions of the perturbative QCD as well as the existing experimental data is presented.

INFRARED RENORMALON EFFECTS ON LIGHT MESONS ELECTROMAGNETIC TRANSITION FORM FACTOR FMγ*(Q2, ω)

2003 ◽  
Vol 18 (07) ◽  
pp. 1023-1050 ◽  
Author(s):  
YEGANA V. MAMEDOVA
Keyword(s):  
Form Factor ◽  
Perturbative Qcd ◽  
Transition Form Factor ◽  
Form Factors ◽  
Transition Form ◽  
Coupling Constant ◽  
Electromagnetic Transition ◽  
Qcd Factorization ◽  
Factorization Formula ◽  
Light Mesons

The light pseudoscalar π0, η and η′ mesons electromagnetic transition γ* + γ* → M form factors FMγ*(Q2,ω) are calculated, applying the perturbative QCD factorization formula and the frozen coupling constant approximation. In the computations the O(αS) order expression for FMγ*(Q2,ω) and the mesons' infrared renormalon corrected distribution amplitudes are used. In the case of the η and η′ mesons, the SUf(3) ordinary octet-singlet mixing scheme is utilized. Comparisons are made with the results obtained, employing the mesons' ordinary distribution amplitudes and with γ + γ* → M transition form factors.

scholarly journals The interplay of transverse degrees of freedom and axial-vector mesons with short-distance constraints in g−2

2021 ◽  
Author(s):  
Pere Masjuan ◽  
Pablo Roig ◽  
Pablo Sanchez Puertas
Keyword(s):  
Short Distance ◽  
Degrees Of Freedom ◽  
Axial Vector ◽  
Form Factors ◽  
Experimental Result ◽  
Special Focus ◽  
Vector Mesons ◽  
Distance Constraints ◽  
The Past

Abstract We revisit well-known short-distance constraints relating the hadronic light-by light Green's function to the〈VVA〉one, that have been a subject of debate over the past years in the context of the muon (g-2). Specifically, we identify a relation among the longitudinal and transverse degrees of freedom that is enforced by the axial anomaly that, by contrast, has not received attention in the past. Such relation allows, among other things, to overcome the problem of basis ambiguities when describing axial-vector mesons transition form factors, but further applications are discussed as well, with special focus on the role of axial-vector mesons in the HLbL contribution to the muon (g-2). Our results should also contribute to a better understanding of the, so far, controversial interplay among short-distance constraints with longitudinal and transverse degrees of freedom, such as axial-vector mesons. This is key to confront the theoretical and experimental result for the muon (g-2) that, currently, exhibits a 4.2σ tension.

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