FCNC PROCESS IN B DECAY AND THE VECTOR MESON DOMINANCE

1999 ◽  
Vol 14 (25) ◽  
pp. 1701-1712
Author(s):  
SURATH KUMAR BISWAS ◽  
V. P. GAUTAM
Keyword(s):  
Vector Meson ◽  
Short Distance ◽  
Distance Effect ◽  
Vector Meson Dominance ◽  
Matrix Elements ◽  
Long Distance ◽  
Inclusive Decays ◽  
The Matrix ◽  
Working Out

We investigate how the vector meson dominance affects the O(αs) virtual corrections in addition to the bremsstrahlung correction while working out the matrix elements for b→sγ and b→ dγ decays. Long-distance effect alone is not appreciable but it is a good supplement to the short-distance contribution. We obtain better results for the inclusive decays.

DOMINANCE OF LONG DISTANCE EFFECTS IN THE KL-KS MASS DIFFERENCE

1990 ◽  
Vol 05 (19) ◽  
pp. 1477-1483 ◽  
Author(s):  
K. TERASAKI ◽  
S. ONEDA
Keyword(s):  
Asymptotic Behavior ◽  
Vector Meson ◽  
Ground State ◽  
Mass Shell ◽  
Mass Difference ◽  
Matrix Elements ◽  
Long Distance ◽  
Distance Effects ◽  
Intermediate States ◽  
The Matrix

It is argued that the asymptotic behavior of the matrix elements of Hw involving on-mass-shell ground-state mesons with infinite momenta, which were instrumental in explaining the |ΔI|=1/2 rule in the K→ππ decays, actually implies [Formula: see text]. The long distance effects (contributions of PS and vector meson poles and ππ intermediate states) may reproduce the observed KL−Ks mass difference, consistent with the |ΔI|=1/2 rule. Its estimate is however sensitive to the η-η′-… mixing.

scholarly journals FEASIBILITY OF EXTRACTING Vtd FROM RADIATIVE B(Bs) DECAYS

1996 ◽  
Vol 11 (20) ◽  
pp. 3743-3759 ◽  
Author(s):  
D. ATWOOD ◽  
B. BLOK ◽  
A. SONI
Keyword(s):  
Vector Meson ◽  
Short Distance ◽  
Experimental Information ◽  
Radiative Decays ◽  
Vector Meson Dominance ◽  
Long Distance

We use experimental information on D−→K*0ρ− and B→ψ+K*, coupled with flavor independence of QCD, and with vector meson dominance, to show that long distance (LD) contributions to B→ρ+γ, especially to B−→ρ−+γ, are potentially very serious. Estimates based on the annihilation graph are shown to lead to similar conclusions. We emphasize that LD contributions can be appreciably different in B−→ρ−+γ and B0→ρ0(ω)+γ. All radiative decays of B, Bs are shown to be governed essentially by two LD and two short distance (SD) hadronic entities. Despite the presence of considerable LD contributions, we show how separate measurements of B−→ρ−+γ, B0→ρ0(ω)+γ, along with B→K*+γ, can be used for a systematic extraction of Vtd. Measurements of Bs→ɸ+γ and K*0+γ could also provide very useful consistency checks.

Inclusive and Exclusive Decay of B- Meson

1997 ◽  
Vol 12 (37) ◽  
pp. 2873-2882 ◽  
Author(s):  
H. Routh ◽  
V. P. Gautam
Keyword(s):  
Large Scale ◽  
B Meson ◽  
Effective Hamiltonian ◽  
Matrix Elements ◽  
Long Distance ◽  
Logarithmic Approximation ◽  
Fermion Operator ◽  
Color Dipole ◽  
The Matrix ◽  
Exclusive Decay

In our letter we deal with the inclusive and exclusive decay of B- meson. The inclusive b→dγ decay has been considered here including the QCD corrections to the Wilson coefficients and the matrix elements of the operators in the effective Hamiltonian. We calculate the O(αs) virtual corrections to the matrix element for b→dγ, taking into account the contributions of the four-fermion operator O2 and the electromagnetic and color dipole type operators. It drastically reduces the large scale dependence of the leading logarithmic approximation. Moreover, while we are considering the exclusive B-→ρ-γ decay, we have taken into consideration both the short distance as well as long distance contributions. Therefore, we have obtained better result for the partial decay width of B-→ρ-γ.

scholarly journals Study on branching ratios and direct CP asymmetries of D → PV decays

2014 ◽  
Vol 29 ◽  
pp. 1460209 ◽  
Author(s):  
Qin Qin ◽  
Hsiang-Nan Li ◽  
Cai-Dian Lü ◽  
Fu-Sheng Yu
Keyword(s):  
Experimental Data ◽  
Pseudoscalar Meson ◽  
Short Distance ◽  
D Mesons ◽  
Branching Ratios ◽  
Matrix Elements ◽  
Long Distance ◽  
Global Fit ◽  
Belle Ii ◽  
Cp Asymmetries

We study the non-leptonic two-body decays of D mesons decaying into one pseudoscalar meson (P) and one vector meson (V) in the factorization-asisted topological-amplitude approach. In this approach, the decay amplitudes are factorized into two parts, the short-distance contribution (Wilson coefficients) and the long-distance contribution (hadronic matrix elements). We predict the branching ratios of D → PV decays using a global fit with the non-perturbative parameters. Our results agree well with the experimental data. We also predict the direct CP asymmetries by combining short-distance dynamics associated with penguin operators and long-distance hadronic matrix elements determined by branching ratios. The large asymmetries in D+ → π+ρ0 and [Formula: see text] may be measurable in the LHCb and future Belle II experiments.

scholarly journals NEW INSIGHTS CONCERNING DIMENSION EIGHT EFFECTS IN WEAK DECAYS

2001 ◽  
Vol 16 (supp01c) ◽  
pp. 1228-1230
Author(s):  
JOHN F. DONOGHUE
Keyword(s):  
Operator Product Expansion ◽  
Short Distance ◽  
Numerical Estimate ◽  
Dimensional Regularization ◽  
Operator Product ◽  
Higher Dimension ◽  
Matrix Elements ◽  
Weak Decays ◽  
The Matrix ◽  
Weak Operator

Most past work on weak nonleptonic decays has mixed dimensional regularization in the weak operator product expansion with some form of a cutoff regularization in the evaluation of the matrix elements. Even with the usual technique of matching the two schemes, this combination misses physics at short distance which can be described by dimension eight (and higher dimension) operators. I describe some recent work with V. Cirigliano and E. Golowich which clarifies these effects and provides a numerical estimate suggesting that they are important.

scholarly journals Gluon fragmentation into 3$$ {P}_J^{\left[1,8\right]} $$ quark pair and test of NRQCD factorization at two-loop level

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Peng Zhang ◽  
Ce Meng ◽  
Yan-Qing Ma ◽  
Kuang-Ta Chao
Keyword(s):  
Short Distance ◽  
Distance Matrix ◽  
Matrix Elements ◽  
Leading Order ◽  
Long Distance ◽  
Loop Level ◽  
Matching Procedure ◽  
Fragmentation Functions ◽  
Infrared Divergences ◽  
Gluon Fragmentation

Abstract The next-to-leading order (NLO) ($$ \mathcal{O} $$ O ($$ {\alpha}_s^3 $$ α s 3 )) corrections for gluon fragmentation functions to a heavy quark-antiquark pair in 3$$ {P}_J^{\left[1,8\right]} $$ P J 1 8 states are calculated within the NRQCD factorization. We use the integration-by-parts reduction and differential equations to semi-analytically calculate the fragmentation functions in full-QCD, and find that infrared divergences can be absorbed by the NRQCD long distance matrix elements. Thus, the NRQCD factorization conjecture is verified at two-loop level via a physical process, which is free of artificial ultraviolet divergences. Through the matching procedure, infrared-safe short distance coefficients and $$ \mathcal{O} $$ O ($$ {\alpha}_s^2 $$ α s 2 ) perturbative NRQCD matrix elements ⟨$$ {\mathcal{O}}^3{P}_J^{\left[1,8\right]} $$ O 3 P J 1 8 (3$$ {S}_1^{\left[8\right]} $$ S 1 8 )⟩ are obtained simultaneously. The NLO short distance coefficients are found to have significant corrections comparing with the LO ones.

scholarly journals RADIATIVE LEPTONIC DECAYS OF THE CHARGED B AND D MESONS INCLUDING LONG-DISTANCE CONTRIBUTION

2012 ◽  
Vol 27 (22) ◽  
pp. 1250120 ◽  
Author(s):  
JI-CHONG YANG ◽  
MAO-ZHI YANG
Keyword(s):  
Short Distance ◽  
D Mesons ◽  
Bound State ◽  
Vector Meson Dominance ◽  
Dominance Model ◽  
Long Distance ◽  
Leptonic Decays ◽  
Bound State Wave Function ◽  
Vector Meson Dominance Model ◽  
Relativistic Potential

In this work, we study the radiative leptonic decays of B-, D-and [Formula: see text], including both the short-distance and long-distance contributions. The short-distance contribution is calculated by using the relativistic quark model, where the bound state wave function we used is that obtained in the relativistic potential model. The long-distance contribution is estimated by using vector meson dominance model.

scholarly journals Estimate of the Long-Distance Contribution Through b→ sψ to the Bs→γγ Decay Rate

1997 ◽  
Vol 12 (37) ◽  
pp. 2837-2846 ◽  
Author(s):  
G. Hiller ◽  
E. O. Iltan
Keyword(s):  
Vector Meson ◽  
Decay Rate ◽  
Charm Quark ◽  
Branching Ratio ◽  
Vector Meson Dominance ◽  
Chain Process ◽  
Quark Loop ◽  
Dominance Model ◽  
Long Distance ◽  
Vector Meson Dominance Model

The Bs→ϕψ decay is modeled through the inclusive b→ sψ decay. Using the vector meson dominance model, the amplitude for the chain process Bs→ϕ;ψ→ϕγ→γγ is estimated and it is found to be at most 4% of the corresponding amplitude from the O7 type LD contribution. The intermediate amplitude for the process Bs→ϕγ is compared with the corresponding one obtained by a different approach based on the interaction of the virtual charm quark loop with soft gluons.7 Both amplitudes are found to agree within 10%. Further the influence on the branching ratio B (Bs→γγ) SD + LD O7 from inclusive b→ sψ is estimated to be less than 1%.

Operations with elements of transferred density matrix via unitary transformations on extended receiver

2020 ◽  
Vol 18 (03) ◽  
pp. 2050007
Author(s):  
A. I. Zenchuk
Keyword(s):  
Density Matrix ◽  
Matrix Elements ◽  
Algebraic Equations ◽  
Quantum State Transfer ◽  
Long Distance ◽  
Linear Combinations ◽  
State Transfer ◽  
Linear Algebraic Equations ◽  
Unitary Transformations ◽  
The Matrix

We combine the long-distance quantum state transfer and simple operations with the elements of the transferred (nor perfectly) density matrix. These operations are turning some matrix elements to zero, rearranging the matrix elements and preparing their linear combinations with required coefficients. The basic tool performing these operations is the unitary transformation on the extended receiver. A system of linear algebraic equations can be solved in this way as well. Such operations are numerically simulated on the basis of 42-node spin-1/2 chain with the two-qubit sender and receiver.

WEAK RADIATIVE DECAY WIDTH OF Λb→Λγ DECAY

2001 ◽  
Vol 16 (31) ◽  
pp. 2013-2019
Author(s):  
A. K. MAITI ◽  
S. KOLA ◽  
D. P. BHATTACHARYYA
Keyword(s):  
Decay Width ◽  
Short Distance ◽  
Close Agreement ◽  
Radiative Decay ◽  
Photon Emission ◽  
Branching Ratio ◽  
Distance Effect ◽  
Long Distance ◽  
Effective Lagrangian ◽  
Quark Level

We have systematically analyzed the two-body weak radiative Λb→Λγ decay of bottom baryon. The weak radiative decay proceeds through W-exchange accompanied by a photon emission. Effective Lagrangian has been used for the W-exchange bremsstrahlung processes to estimate the long distance effect through pole. The short distance effect at the quark level (b→sγ) is also estimated here. With these predictions we have finally obtained the branching ratio of Λb→Λγ as Br (Λb→Λγ)=2.3×10-10 which is in close agreement with the experimental results.

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