arXiv subjects
Publications and source records attributed to Mohammad Ahmady.
We predict the cross-section for diffractive $ϕ$ electroproduction within the dipole model, using a holographic meson wavefunction for the $ϕ$. For the dipole cross-section, we use the Color Glass Condensate dipole model whose parameters are fitted to the latest 2015 combined HERA data on Deep Inelastic Scattering. Choosing a strange quark mass of $0.14$ GeV, we find good agreement with the available data.
We compute the branching ratio and forward-backward asymmetry ($A_{FB}$) distribution for the rare dileptonic decay $B \to K^* μ^+ μ^-$ for the full range of $q^2$, the dimuon mass squared, region. For the required form factors, we use nonperturbative inputs as predicted by the anti-de Sitter (AdS)/QCD correspondence. When using the Breit-Wigner model with momentum-dependent decay constants to account for the $ψ$ and $ψ^\prime$ resonance effects in the nonresonance region of the spectrum, we find our predictions to be in better agreement with the experimental data for the branching ratio.
We build on the success of AdS/QCD in predicting diffractive $ρ$ meson production to obtain the transition form factors for B decays to light mesons. Consequently, we predict several observables associated with $B\to ρ\ellν$ semileptonic and $B\to K^*μ^+μ^-$ dileptonic decays. Our predictions are compared to the available experimental data.
The light front wavefunction obtained from anti-de Sitter Quantum Chromodynamics is used to calculate the light cone distribution amplitudes for $ρ$ and $K^*$ vector mesons. These distribution amplitudes are then utilized to calculate the $B \to ρ,\; K^*$ transition form factors via light cone sum rules. Two-parameter fits of our results for low to intermediate momentum transfer $q^2$ that includes the QCD lattice data at high $q^2$ are presented. Consequently, we give predictions for the semileptoic $B \to ρ\ell ν$ and dileptonic $B \to K^* μ^+ μ^-$ decays.
We use the AdS/QCD distribution amplitudes for light mesons to calculate the transition form factors for B to $ρ$, $K^*$ decays. These form factors are then utilized to make predictions for the semileptonic $B\toρ\ellν$ and dileptonic $B\to K^* μ^+μ^-$ decays. We compare our predictions to the experimental data from BaBar and LHCb.
Light front Holography is a formalism developed by Brodsky and de Téramond in which analytic forms for the hadronic bound state wavefunctions can be obtained. We have used the holographic light front wavefunctions thus obtained in order to calculate the distribution amplitudes of the light vector mesons $ρ$ and $K^*$. As a result, we are able to calculate the form factors for $B\to ρ, K^*$ transitions as well as $Λ_{\rm QCD}/m_b$ contributions in radiative $B_{(s)}\to (ρ,K^*)γ$ decays. We compare our predictions to the available experimental data.
We use AdS/QCD holographic Distributions Amplitudes for the vector mesons $ρ$ and $K^*$ in order to predict the radiative decays $B \to ργ$ and $B \to K^* γ$ as well as the semileptonic decays $B \to ρl ν$ and $B \to K^* μ^+ μ^-$. For the radiative decays, we find that the AdS/QCD DAs offer the advantage of avoiding end-point singularities when computing power suppressed contributions. For the semileptonic decays $B \to ρl ν$ and $B \to K^* μ^+ μ^-$, we compare our predictions to the latest BaBar and LHCb data respectively.
We predict observables in radiative B decays to vector mesons using holographic AdS/QCD Distribution Amplitudes for the vector mesons. We find that end-point divergences can be avoided when computing power-suppressed contributions in the heavy quark limit. The results reported here can be found in references [1] and [2].