Annihilation contributions in B→K1γ decay in next-to-leading order in LEET and CP-asymmetry

Aslam, M. Jamil

doi:10.1140/epjc/s10052-006-0151-0

“…The study on rare decay of Λ b → Λ+γ and Λ b → Λ+l + l − can serve as the baryonic counterparts of analysis on B → K * γ [11,12,13,14,15,16,17,18,19,20,21], B → K * l + l − [5,6,7,8,9,10] and could also be the extension of investigations on heavy baryon decays Λ b → plν [63] and Λ c → Λlν [64]. Such decays play the role as a corner stone [121] to explore the quark-flavor structure of the SM as well as determine its fundamental parameters such as the CKM matrix.…”

Section: Discussionmentioning

confidence: 99%

“…Combining the Eq. (19,20), (43,44) and summing over the polarization of Λ b baryon, we can obtain the phenomenological representations of correlation function as…”

Section: B Parameterizations Of Hadronic Matrix Elementmentioning

confidence: 99%

“…On the contrary, the experimental investigations of exclusive decays are comparably easier; while the theoretical analysis of these modes encounter formidable difficulties due to lack of good understanding of QCD at low energy. As a matter of fact, there have been extensive studies on the exclusive decays of B → M l + l − [5,6,7,8,9,10], B → V (A) γ [11,12,13,14,15,16,17,18,19,20,21] in the literature with varying degrees of theoretical rigor and emphasis. Unlike mesonic decays, the investigations of FCNC b → s transition for bottom baryonic decays Λ b → Λγ and Λ b → Λl + l − are much behind because more degrees of freedom are involved in the bound state of baryon system at the quark level.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Rare decays of Λ b →Λ+γ and Λ b →Λ+l + l − in the light-cone sum rules

Wang

¹

,

Li

²

,

Lü

³

2009

View full text Add to dashboard Cite

The weak decays of Λ b → Λ + γ and Λ b → Λ + l + l − are investigated in the Standard Model using light-cone sum rules approach. The higher twist distribution amplitudes of Λ baryon to the leading conformal spin are included in the sum rules for transition form factors. Our results indicate that the higher twist distribution amplitudes almost have no influences on the transition form factors retaining the heavy quark spin symmetry, while such corrections can result in significant impacts on the form factors breaking the heavy quark spin symmetry. Two phenomenological models (COZ and FZOZ) for the wave function of Λ baryon are also employed in the sum rules for a comparison, which can give rise to the form factors approximately five times larger than that in terms of conformal expansion. Utilizing the form factors calculated in LCSR, the physical observables like decay rate, polarization asymmetry and forward-backward asymmetry are analyzed for the decays of Λ b → Λγ, Λl + l − . I. INTRODUCTION Generally, new physics can be accessible through rare decays, where the contributions from the Standard Model (SM) are suppressed enough. Hence, such decays can provide an ideal platform to test the SM precisely as well as to bound new physics parameters stringently. Rare decays involving b → s flavor changing neutral current (FCNC), which are forbidden at the tree level in the standard model, can only be induced by Glashow-Iliopoulos-Maiani mechanism [1] via loop diagrams. The Cabibbo-Kobayashi-Maskawa (CKM) matrix [2, 3] elements can be determined quantitatively from b → s rare decays, B 0 s −B 0 s mixing [4] etc., which will test its unitarity under the requirement of the SM.It is well known that the inclusive decays are relatively robust theoretically, since the decay rate can be systematically and reasonably approximated by the decay of a free b quark into light quarks, gluons and photons; but the counterpart of experimental measurements are quite difficult. On the

show abstract

“…But the mixing angle is not uniquely determined only using the τ → K 1 (1270)ν and τ → K 1 (1400)ν data. Thus radiative and semileptonic B decay channels not only provide valuable information on weak interactions but also offer an opportunity to detect the internal structure of the K 1 mesons [1,2,3,4,5,6,7,8,9,10,11,12,13]. In our previous work [14,15], we have studied the B → A form factors in the perturbative QCD (PQCD) approach.…”

Section: Introductionmentioning

confidence: 99%

Branching ratios, forward-backward asymmetry, and angular distributions ofB→K1l+l−decays

Li

¹

,

Lu

²

,

Wang

³

2009

View full text Add to dashboard Cite

Using the B → K1 form factors evaluated in the perturbative QCD approach, we study semileptonic B → K1(1270)l + l − and B → K1(1400)l + l − decays, where K1(1270) and K1(1400) are mixtures of K1A and K1B which are 3 P1 and 1 P1 states, respectively. Using the technique of helicity amplitudes, we express the decay amplitudes in terms of several independent and Lorentz invariant pieces. We study the dilepton invariant mass distributions, branching ratios, polarizations and forward-backward asymmetries of B → K1l + l − decays. The ambiguity in the sign of the mixing angle will induce very large differences to branching ratios of semileptonic B decays: branching ratios without resonant contributions either have the order of 10 −6 or 10 −8 . But the polarizations and the forward-backward asymmetries are not sensitive to the mixing angles. We find that the resonant contributions will dramatically change the dilepton invariant mass distributions in the resonant region. We also provide the angular distributions of B → K1l + l − → (Kππ)l + l − decays.

show abstract

“…But the mixing angle is not uniquely determined only using the τ → K 1 (1270)ν and τ → K 1 (1400)ν data. Thus radiative and semileptonic B decay channels not only provide valuable information on weak interactions but also offer an opportunity to detect the internal structure of the K 1 mesons [1,2,3,4,5,6,7,8,9,10,11,12,13].…”

Section: Introductionmentioning

confidence: 99%

Branching Ratios, Forward-backward Asymmetry and Angular Distributions of $B\to K_1l^+l^-$ Decays

Li,

Lü,

Wang

2009

Preprint

View full text Add to dashboard Cite

Using the B → K1 form factors evaluated in the perturbative QCD approach, we study semileptonic B → K1(1270)l + l − and B → K1(1400)l + l − decays, where K1(1270) and K1(1400) are mixtures of K1A and K1B which are 3 P1 and 1 P1 states, respectively. Using the technique of helicity amplitudes, we express the decay amplitudes in terms of several independent and Lorentz invariant pieces. We study the dilepton invariant mass distributions, branching ratios, polarizations and forward-backward asymmetries of B → K1l + l − decays. The ambiguity in the sign of the mixing angle will induce very large differences to branching ratios of semileptonic B decays: branching ratios without resonant contributions either have the order of 10 −6 or 10 −8 . But the polarizations and the forward-backward asymmetries are not sensitive to the mixing angles. We find that the resonant contributions will dramatically change the dilepton invariant mass distributions in the resonant region. We also provide the angular distributions of B → K1l + l − → (Kππ)l + l − decays.

show abstract

Annihilation contributions in B→K1γ decay in next-to-leading order in LEET and CP-asymmetry

Cited by 10 publications

References 45 publications

Rare decays of Λ b →Λ+γ and Λ b →Λ+l + l − in the light-cone sum rules

Rare decays of Λ b →Λ+γ and Λ b →Λ+l + l − in the light-cone sum rules

Branching ratios, forward-backward asymmetry, and angular distributions ofB→K1l+l−decays

Branching Ratios, Forward-backward Asymmetry and Angular Distributions of $B\to K_1l^+l^-$ Decays

Contact Info

Product

Resources

About