In this work, we investigate the semi-leptonic weak decays of spin-1/2 doubly-heavy baryons $Ξ_{QQ^{\prime}}$ into spin-3/2 singly-heavy baryons $Σ_{Q^{\prime}}^*$ within light-cone sum rules. Using the parallel components of the light-cone distribution amplitudes of $Σ_{Q^{\prime}}^*$, the transition form factors for these decays are calculated both analytically and numerically. The numerical results for these semi-leptonic weak decays widths and branching ratios are also predicted, which are compared with the same predictions by other theoretical approaches in the literatures. These phenomenology predictions can be tested by the experiments in the future.
The strong $D^{*}_sD_{s}η^{(\prime)}$ and $B^{*}_sB_{s}η^{(\prime)}$ vertices are studied and the relevant couplings are calculated in the context of the light-cone QCD sum rule method with twist-4 accuracy by including the next-to-leading order corrections. In the analysis, both the quark and gluon components of the $η$ and $η^{\prime}$ mesons and the axial anomaly corrected higher twist distributions are included.
The $Ξ_Q^\prime$-$Ξ_Q$ transition magnetic moments are calculated in framework of the light cone QCD sum rules method (LCSR). The values of the transition magnetic moments obtained are compared with the predictions of the other theoretical approaches.
As a continuation of our previous work, we investigate the weak decays of doubly-heavy baryons $Ξ_{QQ^{\prime}}$ into sextet $Σ_{Q^{\prime}}$ with light-cone sum rules. We calculate the form factors for these decays with the parallel light-cone distribution amplitudes of $Σ_{Q^{\prime}}$. Numerical results of these form factors are used to predict the decay widths and branching ratios of the corresponding semi-leptonic processes. Parametric uncertainties and theoretical analyses are also given in detail. We find that the decay widths of $Ξ_{cc}$ and $Ξ_{bc}$ decays are several orders of magnit…
We analyze the weak decay of doubly-heavy baryon decays into anti-triplets $Λ_Q$ with light-cone sum rules. To calculate the decay form factors, both bottom and charmed anti-triplets $Λ_b$ and $Λ_c$ are described by the same set of leading twist light-cone distribution functions. With the obtained form factors, we perform a phenomenology study on the corresponding semi-leptonic decays. The decay widths are calculated and the branching ratios given in this work are expected to be tested by future experimental data, which will help us to understand the underlying dynamics in doubly-heavy baryon …
We present an improved light-cone sum rule analysis of the decay form factors of $D$ and $D_s$ into $η$ and $η^{\prime}$ and argue that these decays offer a very promissing possibility to determine the leading Fock-state gluonic contribution of the $η'$ at future experimental facilities as FAIR or Super-KEKB. We also give the corresponding branching ratios for B decays.
We calculate the magnetic dipole and electric quadrupole moments associated with the radiative $Ω_{Q}^{*}\rightarrowΩ_{Q}γ$ and $Ξ_{Q}^{*}\rightarrowΞ^{\prime}_{Q}γ$ transitions with $Q=b$ or $c$ in the framework of light cone QCD sum rules. It is found that the corresponding quadrupole moments are negligibly small while the magnetic dipole moments are considerably large. A comparison of the results on the considered multipole moments as well as corresponding decay widths with the predictions of the vector dominance model is performed.
The light cone sum rules method is used in studying the radiative decays $Σ_Q \to Λ_Q γ$ and $Ξ^\prime_Q \to Ξ_Q γ$. Firstly, the sum rules for the form factor $F_2(Q^2=0)$ responsible for these transitions is constructed. Using this result the decay widths of the above--mentioned decays are calculated and analyzed. A comparison of our predictions on the decay widths of considered transitions with the predictions of the other approaches is presented.
Probing the $\bar ss$ content of the $η$ and $η'$ mesons and considering mixing between these states as well as gluonic contributions, the form factors responsible for semileptonic $D_s \to (η, η') l ν$ transitions are calculated via light cone QCD sum rules. Corresponding branching fractions and their ratio for different mixing angles are also obtained. Our results are in a good consistency with experimental data as well as predictions of other nonperturbative approaches.
The coupling constant of f0-->omega-gamma decay is calculated using 3-point sum rule and light cone QCD sum rules. We investigate the results within the two-models which depend on mixing angle.
The coupling constant of g_phi-pion-gamma decay is calculated using light cone QCD sum rules. A comparison of our result with the ones existing in the literature is presented.
We investigate the a0-omega-gamma vertex and estimate the coupling constant in the framework of the light cone QCD sum rules. We compare our result with the value of the coupling constant was calculated in the QCD sum rules.
In this article, we use the light-cone QCD sum rules to relate the $Λ_b$ baryon light-cone distribution amplitudes to the Isgur-Wise function $ξ(ω)$ of the $Λ_b \to Λ_c$ transition, and obtain a simple relation. The numerical value of the Isgur-Wise function $ξ(ω)$ is consistent with the prediction of the QCD sum rules.
We calculate the form factors V, A_1, A_2 and A_0 appearing in the (D -> phi) transition in light cone QCD sum rule method. We compare our results on these form factors with the current experimental results and existing theoretical calculations.
The axial N-> Delta(1232) transition form factors are calculated within the light cone QCD sum rules method. A comparison of our results with predictions of lattice theory and quark model calculations is pre- sented.
We investigate the $ωσγ$-vertex and estimate the coupling constant g$_{ωσγ}$ in the framework of the light cone QCD sum rules. We compare our result with the values of this coupling constant deduced from a phenomenological analysis of $ω\toππγ$ decays.
The radiative $Δ\to γN$ transition is examined at the real photon point $Q^2=0$ using the framework of light-cone QCD sum rules. In particular, we determine the sum rules for the transition form factors $G_M(0)$ and $R_{EM}$ up to twist 4.
The strong coupling constants g_{K LAMBDA N} and g_{K SIGMA N} for the structure (sigma_{mu,nu} gamma_5) are calculated within light cone QCD sum rules. A comparison of our results on these couplings with predictions from traditional QCD sum rules is presented.
The radiative decays of heavy baryons and lowest three doublets of heavy mesons are studied with the light cone QCD sum rules in the leading order of heavy quark effective theory.
A short introduction is given to the method of light-cone sum rules, their theoretical background and main modifications. The discussion is concentrated but not restricted to the applications to heavy quark decays.
We outline the developed approach within the light-cone sum rules at the leading order for calculation of the gravitational form factors related to the nucleon valence quark combinations. The predictions for the gravitational form factor $D(t)$ ($D$-term contributions) have been presented.
The tensor form factors of $B$ into p--wave axial vector meson transition are calculated within light cone QCD sum rules method. The parametrizations of the tensor form factors based on the series expansion are presented.
For the heavy baryons $Ξ_c$ and $Ξ_b$ the coupling constants $g_{Ξ_cΞ_cπ}$ and $g_{Ξ_bΞ_bπ}$ are calculated in the framework of light cone QCD sum rules. The most general form of the interpolating field of $Ξ_Q$ is used in the calculation.
We calculate the "pi Sigma Lambda" and "pi Sigma Sigma" coupling constants in light cone QCD sum rules for the structure "sigma_{alpha beta} gamma_5 p^alpha q^beta". A comparison of our results on these coupling constants with prediction of the SU(3) symmetry is presented.
The magnetic moments of heavy $Ξ_{Q}$ baryons containing a single charm or bottom quark are calculated in the framework of light cone QCD sum rules method. A comparison of our results with the predictions of the quark models is presented.
We present the application of the method of light-cone sum rules to the determination of baryonic form factors at intermediate momentum transfer. After reviewing the current status of this field we give some outlook on possible future projects.
Using the recent results for the two-parton light-cone distribution amplitudes of the tensor meson, we calculate the form factors for the decays of $B_{u,d,s}$ into the light $J^{PC}=2^{++}$ tensor mesons via the vector/axial-vector/tensor current with the light-cone sum rules. We also obtain the $q^2$-dependence of the form factors.
We calculate the transition formfactors for the B -> K l(+) l(-) decay in the framework of the light cone QCD sum rules. The invariant dilepton mass distribution and the final lepton longitudinal polarization asymmetry are investigated. The comparison analysis of our results with traditional sum rules method predictions on the formfactors is performed.
We have analyzed the $B\to π$ and $B_{s}\to K$ semileptonic form factors and $B\to Vγ(V=K^*,ρ,ω)$ processes in the light-cone QCD sum rules. In order to enhance the predictivity and reliability of numerical results the chiral-current correlator is employed and the twist-3 light-cone wavefunction can be effectively eliminated from the sum rules.
The magnetic and quadrupole moments of the light-vector and axial-vector mesons are calculated in the light cone QCD sum rules. Our results for the static properties of these mesons are compared with the predictions of lattice QCD as well as other approaches existing in the literature.
Recently, LHCb Collaboration announced the discovery of radial excitations of $D_s$ and $B_s$ mesons. In present work, we calculate the most promising strong and electromagnetic decay widths of radially excited $D_s(2S)$ and $B_s(2S)$ mesons within the light cone QCD sum rules method.
We investigate the $a_0K^+K^-$-vertex in the framework of light cone QCD sum rules. We estimate the coupling constant g$_{a_0K^+K^-}$ which is an essential ingredient in the analysis of physical processes involving $a_0(980)$ meson. Our result is somewhat larger than the previous determinations of this coupling constant.
New sum rules for $B\to π,K $ and $B\to ρ,K^*$ form factors are derived from the correlation functions expanded near the light-cone in terms of B-meson distribution amplitudes. The contributions of quark-antiquark and quark-antiquark-gluon components in the B meson are taken into account. Models for the B-meson three-particle distribution amplitudes are suggested, based on QCD sum rules in HQET. Employing the new light-cone sum rules we calculate the form factors at small momentum transfers, including $SU(3)_{fl}$ violation effects. The results agree with the predictions of the conventional li…
Using the general form of the (Sigma^0) and (Lambda) currents, the (Sigma^0-Lambda) transition magnetic moment is calculated in framework of the light cone QCD sum rules. A comparison of our result on this quantity with the existing theoretical results and experimental data is presented.
We suggest a new approach for calculating heavy-to-light form factors. The method is based on light cone sum rules (LCSR) and covers the whole kinematical range of momentum transfer. The derivation of the new sum rule uses a suitable combination of double and single dispersion integrals. As an example we give numerical results for the form factor f^+ for the B -> pion transition.
We discuss the calculation of the $B \rightarrow π$ and $D \rightarrow π$ form factors based on an expansion in terms of pion wave functions on the light-cone with increasing twist and QCD sum rule methods. The results are compared with predictions of conventional QCD sum rules and other approaches.
In this article, we study the $B \to K^*_2(1430)$, $a_2(1320)$, $f_2(1270)$ form-factors with the light-cone QCD sum rules, where the $B$-meson light-cone distribution amplitudes are used. In calculations, we observe that the line-shapes of the $B$-meson light-cone distribution amplitude $ϕ_+(ω)$ have significant impacts on the values of the form-factors, and expect to obtain severe constraints on the parameters of the $B$-meson light-cone distribution amplitudes from the experimental data in the future.
Strong decay constants of the heavy tensor to heavy pseudoscalar (vector) and light pseudoscalar mesons are estimated within the light cone QCD sum rules. It is obtained that the values of these coupling constants are very strongly dependent on the choice of the Lorentz structure. Moreover, using these strong coupling constants the corresponding decay widths are calculated.
The couplings of pions with heavy baryons g_2 (Σ^*, Σ) and g_3(Σ^*, Λ) are studied with light-cone QCD sum rules in the leading order of heavy quark effective theory. Both sum rules are stable. Our results are g_2=(1.56\pm 0.3), g_3=(0.94\pm 0.06).
Using the most general form of the interpolating currents, the coupling constants $g_{Σ_bΣ_bπ}$ and $g_{Σ_cΣ_cπ}$ are calculated within the light cone QCD sum rules approach. It is found that $g_{{Σ_{c}Σ_{c}π}}=-8.0\pm1.7$ and $g_{{Σ_{b}Σ_{b}π}}=-11.0\pm2.1$.
The radiative decays $ B^{*} (D^{*})\to B(D) γ$ are investigated in the framework of light cone QCD sum rules. The transition amplitude and decay rates are estimated.It is shown that our results on branching ratios of D meson decays are in good agreement with the existing experimental data.
Electromagnetic form factors of the transition $π+γ_{virt.}\ra A_1$ are calculated by QCD sum rules technique with the description of the pion in terms of the set of wave functions of increasing twist. Obtained results are compared with standard QCD sum rule calculations.
We describe the construction of light-cone sum rules (LCSRs) for exclusive $B$-meson decays into light energetic hadrons from correlation functions within soft-collinear effective theory (SCET). As an example, we consider the SCET sum rule for the $B \to π$ transition form factor at large recoil, including radiative corrections from hard-collinear loop diagrams at first order in the strong coupling constant.
The magnetic moments of heavy sextet $J^P = {1\over 2}^+$ baryons are calculated in framework of the light cone QCD sum rules method. Linearly independent relations among the magnetic moments of these baryons are obtained. The results for the magnetic moments of heavy baryons obtained in this work are compared with the predictions of the other approaches.
In this article, we calculate the strong coupling constant $g_{ΔNπ}$ and study the strong decay $Δ^{++} \to pπ$ with the light-cone QCD sum rules. The numerical value of the strong coupling constant $g_{ΔNπ}$ is consistent with the experimental data. The small discrepancy maybe due to failure to take into account the perturbative $\mathcal {O}(α_s)$ corrections.
The radiative decays $ B^{*} (D^{*})\rightarrow B(D) γ$ are investigated in the framework of light cone QCD sum rules. The transition amplitude and decay rates are estimated.It is shown that our results on branching ratios of D meson decays are in good agreement with the existing experimental data.
Octet baryon magnetic moments are calculated in framework of the light cone QCD sum rules. The analysis is carried for the general form of the interpolating currents for octet baryons. A comparison of our results on the magnetic moments of octet baryons with the predictions of other approaches and experimental data is presented.
Light-cone sum rules have proved to be very useful in calculating hadronic matrix elements for exclusive processes. I present recent applications of this method to the pion electromagnetic form factor and to the form factors of $γ^* ρ\to π$ and $γ^*γ\to π^0$ transitions.
We examine the radiative $Δ\to γN$ transition at the real photon point $Q^2=0$ using the framework of light-cone QCD sum rules. In particular, the sum rules for the transition form factors $G_M(0)$ and $R_{EM}$ are determined up to twist 4. The result for $G_M(0)$ agrees with experiment within 10% accuracy. The agreement for $R_{EM}$ is also reasonable. In addition, we derive new light-cone sum rules for the magnetic moments of nucleons, with a complete account of twist-4 corrections based on a recent reanalysis of photon distribution amplitudes.
We complete the set of QCD light-cone sum rules for $B\to ππ$ transition form factors, deriving a new sum rule for the timelike-helicity form factor $F_t$ in terms of dipion distribution amplitudes. This sum rule, in the leading twist-2 approximation, is directly related to the pion vector form factor. Employing a relation between $F_t$ and other $B\to ππ$ form factors we obtain also the longitudinal-helicity form factor $F_0$. In this way, all four (axial-)vector $B\to ππ$ form factors are predicted from light-cone sum rules with dipion distribution amplitudes. These results are valid for sma…
The introduction of an explicit negative radial excitation contribution in the hadronic side of the light cone QCD sum rule (LCSR) of Belyaev, Braun, Khodjamirian and Ruckl, can explain the large experimental value of g(D*Dpi), recently measured by CLEO. At the same time, it considerably improves the stability of the sum rule when varying the Borel parameter.
We calculate the magnetic moments of Delta baryons within the framework of QCD sum rules. A comparison of our results on the magnetic moments of the Delta baryons with the predictions of different approaches is presented.
Using the most general form of the interpolating currents of heavy baryons, the magnetic moments of heavy baryons "Lambda_Q (Q=b,c)" are calculated in framework of the light cone QCD sum rules. A comparison of our results on magnetic moments with the existing theoretical results calculated in various other frameworks are presented.
We investigate the electromagnetic form factors of the (rho) meson in light cone QCD sum rules. We find that the ratio of the magnetic and charge form factors is larger than two at all values of Q^2, (Q^2 >= 0.5 GeV^2). The values of the individual form factors at fixed values of Q^2 predicted by the light cone QCD sum rules are quite different compared to the results of other approaches. These results can be checked in future, when more precise data on (rho) meson form factors is available.
The transition magnetic dipole and electric quadrupole moments of the radiative decays of the sextet heavy flavored spin 3/2 to the heavy spin 1/2 baryons are calculated within the light cone QCD sum rules approach. Using the obtained results, the decay rate for these transitions are also computed and compared with the existing predictions of the other approaches.
The couplings of pions with lowest three doublets (0^-,1^-), (0^+,1^+) and (1^+,2^+) of heavy mesons are studied with ligh cone QCD sum rules in the leading order of heavy quark effective theory. The ambiguity due to the presence of two distinct 1^+ states are solved.
Using the light cone QCD Sum Rules Method, we study the rare B -> nu barnu gamma decay and and find that the branching ratios are, B(B_s -> nu barnu gamma) = 7.5 10^{-8}, B(B_d -> nu -> nu gamma) = 4.2 10^{-9}. A comparision of our results, on branching ratio, with constituent quark and pole dominance model predictions are presented.
In this article, we calculate the contribution from the nonfactorizable soft hadronic matrix element to the decay $B^0\to χ_{c1} π^0$ with the light-cone QCD sum rules. The numerical results show that its contribution is rather large and should not be neglected. The total amplitudes lead to a branching fraction which is in agreement with the experimental data marginally.
