scholarly journals Exact heavy to light meson form factors in the combined heavy quark, large N{sub c} and chiral limits

10.2172/71709 ◽  
1993 ◽  
Author(s):  
B. Grinstein ◽  
P. Mende
Keyword(s):  
Heavy Quark ◽  
Form Factors ◽  
Light Meson ◽  
Large N

scholarly journals B(s), D(s)→ π, K, η, ρ, K*, ω, ϕ TRANSITION FORM FACTORS AND DECAY RATES WITH EXTRACTION OF THE CKM PARAMETERS |Vub|, |Vcs|, |Vcd|

2006 ◽  
Vol 21 (30) ◽  
pp. 6125-6172 ◽  
Author(s):  
Y. L. WU ◽  
M. ZHONG ◽  
Y. B. ZUO
Keyword(s):  
Heavy Quark ◽  
Radiative Decay ◽  
Form Factors ◽  
Effective Field ◽  
Decay Rates ◽  
Light Meson ◽  
Meson Mass ◽  
Transition Form ◽  
Systematic Calculation ◽  
Light Mesons

A systematic calculation for the transition form factors of heavy to light mesons (B, Bs, D, Ds→ π, K, η, ρ, K*, ω, ϕ) is carried out by using light-cone sum rules in the framework of heavy quark effective field theory. The heavy quark symmetry at the leading order of 1/mQexpansion enables us to reduce the independent wave functions and establish interesting relations among form factors. Some relations hold for the whole region of momentum transfer. The meson distribution amplitudes up to twist-4 including the contributions from higher conformal spin partial waves and light meson mass corrections are considered. The CKM matrix elements |Vub|, |Vcs| and |Vcd| are extracted from some relatively well-measured decay channels. A detailed prediction for the branching ratios of heavy to light meson decays is then presented. The resulting predictions for the semileptonic and radiative decay rates of heavy to light mesons (B, Bs, D, Ds→ π, K, η, ρ, K*, ω, ϕ) are found to be compatible with the current experimental data and can be tested by more precise experiments at B-factory, LHCb, BEPCII and CLEOc.

scholarly journals Consistent treatment of rapidity divergence in soft-collinear effective theory

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Junegone Chay ◽  
Chul Kim
Keyword(s):  
Heavy Quark ◽  
Soft Mode ◽  
Form Factors ◽  
Effective Theory ◽  
Large Rapidity ◽  
Soft Modes ◽  
Heavy Quark Mass ◽  
Soft Collinear Effective Theory ◽  
Matching Procedure ◽  
Consistent Treatment

Abstract In soft-collinear effective theory, we analyze the structure of rapidity divergence due to the collinear and soft modes residing in disparate phase spaces. The idea of an effective theory is applied to a system of collinear modes with large rapidity and soft modes with small rapidity. The large-rapidity (collinear) modes are integrated out to obtain the effective theory for the small-rapidity (soft) modes. The full SCET with the collinear and soft modes should be matched onto the soft theory at the rapidity boundary, and the matching procedure becomes exactly the zero-bin subtraction. The large-rapidity region is out of reach for the soft mode, which results in the rapidity divergence. The rapidity divergence in the collinear sector comes from the zero-bin subtraction, which ensures the cancellation of the rapidity divergences from the soft and collinear sectors. In order to treat the rapidity divergence, we construct the rapidity regulators consistently for all the modes. They are generalized by assigning independent rapidity scales for different collinear directions. The soft regulator incorporates the correct directional dependence when the innate collinear directions are not back-to-back, which is discussed in the N-jet operator. As an application, we consider the Sudakov form factor for the back-to-back collinear current and the soft-collinear current, where the soft rapidity regulator for a soft quark is developed. We extend the analysis to the boosted heavy quark sector and exploit the delicacy with the presence of the heavy quark mass. We present the resummed results of large logarithms in the form factors for various currents with the light and the heavy quarks, employing the renormalization group evolution on the renormalization and the rapidity scales.

scholarly journals Critical analysis of theoretical estimates forB-to-light-meson form factors andB→ψK(K*) data using factorization

1995 ◽  
Vol 51 (11) ◽  
pp. 6235-6252 ◽  
Author(s):  
R. Aleksan ◽  
A. Le Yaouanc ◽  
L. Oliver ◽  
O. Pène ◽  
J.-C. Raynal
Keyword(s):  
Critical Analysis ◽  
Form Factors ◽  
Light Meson

scholarly journals TRANSVERSE CHARGE AND MAGNETIZATION DENSITIES IN THE NUCLEON'S CHIRAL PERIPHERY

2014 ◽  
Vol 25 ◽  
pp. 1460036 ◽  
Author(s):  
C. GRANADOS ◽  
C. WEISS
Keyword(s):  
Form Factors ◽  
High Energy ◽  
Effective Field ◽  
Light Front ◽  
Chiral Effective Field Theory ◽  
Independent Manner ◽  
Generalized Parton Distributions ◽  
Large N ◽  
Mechanical Interpretation ◽  
High Energy Scattering

In the light–front description of nucleon structure the electromagnetic form factors are expressed in terms of frame–independent transverse densities of charge and magnetization. Recent work has studied the transverse densities at peripheral distances [Formula: see text], where they are governed by universal chiral dynamics and can be computed in a model–independent manner. Of particular interest is the comparison of the peripheral charge and magnetization densities. We summarize (a) their interpretation as spin–independent and –dependent current matrix elements; (b) the leading–order chiral effective field theory results; (c) their mechanical interpretation in the light–front formulation; (d) the large–Nc limit of QCD and the role of Δ intermediate states; (e) the connection with generalized parton distributions and peripheral high–energy scattering processes.

scholarly journals Dispersive analysis of light-meson transition form factors

2019 ◽  
Vol 218 ◽  
pp. 03001
Author(s):  
Bastian Kubis
Keyword(s):  
Light Scattering ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Form Factors ◽  
Experimental Information ◽  
Light Meson ◽  
Transition Form ◽  
Dispersive Analysis

We discuss status and prospects of a dispersive analysis of the π0, η, and η ′ transition form factors. Particular focus is put on the various pieces of experimental information that serve as input to such a calculation. These can help improve on the precision of an evaluation of the light pseudoscalar pole contributions to hadronic light-by-light scattering in the anomalous magnetic moment of the muon.**

Symmetry-breaking corrections to the form factors for heavy-to-heavy B-meson at large recoil

2019 ◽  
Vol 34 (08) ◽  
pp. 1950046
Author(s):  
Saba Shafaq ◽  
Ishtiaq Ahmed ◽  
M. Jamil Aslam
Keyword(s):  
Perturbation Theory ◽  
Symmetry Breaking ◽  
Heavy Quark ◽  
B Meson ◽  
Form Factors ◽  
Heavy Meson ◽  
Effective Theory ◽  
Vertex Corrections ◽  
Soft Collinear Effective Theory ◽  
Heavy Quark Limit

The present study investigates the decay of B to heavy meson using the soft collinear effective theory. By assigning different loop momenta, the factorization has been tested and it is found to be valid to all orders in the perturbation theory. It is noted that theory contains one hard collinear and two soft modes depending upon virtuality of different momenta. In the next step, symmetry-conserving relations (in heavy quark limits) to the form factors have been studied. These relations are then used to parametrize the form factors to get symmetry-breaking corrections. These symmetry-breaking corrections can be calculated using perturbative (vertex corrections) as well as nonperturbative (hard spectator interactions) QCD. It is found that in the heavy quark limit, these symmetry contributions do not contribute to the form factors that appear in physical observables for the case of [Formula: see text] decays which are contrary to the heavy-to-light meson decays.

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