Weak Annihilation Contribution to Angular Observables in $B_c^{+}\to D^{\ast +}{\ell }^{+}{\ell }^{-}$ Decays

Abstract

We analyze the rare semileptonic decays $B_c^{+}\to D^{\ast +}(\to P_1{P}_2){\ell }^{+}{\ell }^{-}$, with $P_1{P}_2=D^{+}{\pi }^0$ or $D^0{\pi }^{+}$, and $\ell =\mu ,\tau$. We focus on the impact of weak annihilation contributions alongside penguin, box, and long-distance effects. Using the effective Hamiltonian for $b\to d{\ell }^{+}{\ell }^{-}$ transitions and $B_c\to D^{\ast }$ form factors from covariant confined quark model inputs, we compute the differential branching ratios, forward-backward asymmetry, longitudinal helicity fraction of the $D^{\ast }$, and various normalized angular coefficients. The results of the observables show that weak annihilation effects are sizable, particularly at low $q^2$, significantly modifying several observables and shifting zero-crossings. Resonance effects dominate at high $q^2$, restricting reliable analysis windows. We conclude that the inclusion of weak annihilation is essential for precise Standard Model predictions and for isolating possible New Physics effects in $B_c^{+}\to D^{\ast +}{\ell }^{+}{\ell }^{-}$ decays.

18 pages, 8 figures

References in corpus (35)

• Systematic approach to exclusive B ->V l^+l^-, V gamma decays
• Calculation of two-loop virtual corrections to b --> s l+ l- in the standard model
• Observation of the Baryonic Flavor-Changing Neutral Current Decay Lambda_b -> Lambda mu+ mu-
• Two-loop virtual corrections to B --> X_s l^+ l^- in the standard model
• Three-loop matching of the dipole operators for b -> s gamma and b -> s g
• Generalised helicity formalism, higher moments and the $B\to K_{J_K}(\to K\pi ){\bar{\ell }}_1{\ell }_2$ angular distributions
• Phenomenology of semileptonic B-meson decays with form factors from lattice QCD
• Hadronic uncertainties in $B\to K^{\ast }{\mu }^{+}{\mu }^{-}$: a state-of-the-art analysis
• Analyzing new physics in the decays ${\bar{B}}^0\to D^{(\ast )}{\tau }^{-}{\bar{\nu }}_{\tau }$ with form factors obtained from the covariant quark model
• $B$ Flavour Anomalies: 2021 Theoretical Status Report
• Analytic calculation of two-loop QCD corrections to b\to s\ell^+\ell^- in the high q^2 region
• Rare semileptonic decays of B and B_c mesons in the relativistic quark model
• Extracting Angular Observables without a Likelihood and Applications to Rare Decays
• Study of Rare $B_c^{+}\to D_{d,s}^{(\ast )+}l\bar{l}$ Decays
• Model independent analysis of New Physics effects on $B_c\to (D_s,D_s^{\ast }){\mu }^{+}{\mu }^{-}$ decay observables
• Analysis of the Rare $B_c\to D_{s,d}^{\ast }{l}^{+}{l}^{-}$ Decays in QCD
• On the meson mass spectrum in the covariant confined quark model
• The two-body B_c {\to} D^{(*)}_{(s)}P, D^{(*)}_{(s)}V decays in the Perturbative QCD Approach
• Model-independent analysis of $b\to d$ processes
• Analysis of the rare semileptonic $B_c \rar P(D,D_s) l^{+}l^{-}/ν\barν$ decays within QCD sum rules
• Semileptonic decays $B_c^{+}\to D_{(s)}^{(\ast )}(l^{+}\nu ,l^{+}{l}^{-},\nu \bar{\nu })$ in the perturbative QCD approach
• Semileptonic $D_q\to K_1\ell \nu$ and nonleptonic $D\to K_1\pi$ decays in three--point QCD sum rules and factorization approach
• Semileptonic decays of $B_c$ mesons into charmonium states
• Light-front quark model analysis of the exclusive rare $B_c\to D_{(s)}({\ell }^{+}{\ell }^{-},{\nu }_{\ell }{\bar{\nu }}_{\ell })$ decays
• The rare semi-leptonic $B_c$ decays involving orbitally excited final mesons
• Method for an unbinned measurement of the $q^2$ dependent decay amplitudes of ${\bar{B}}^0\to {\bar{K}}^{\ast 0}{\mu }^{+}{\mu }^{-}$ decays
• Footprints of New Physics in the angular distribution of $B_c\to D_s^{\ast }(\to D_s\gamma ,(D_s\pi )){\ell }^{+}{\ell }^{-}$ decays
• B_c meson rare decays in the light-cone quark model
• Study of Bc-> D_s^* \ell^+ \ell^- in Single Universal Extra Dimension
• Investigation of rare semileptonic $B_c$ decays into $(D_{(}s,d{)}^{(}(\ast ))){\mu }^{+}{\mu }^{-}$ decays with non-universal $Z^{\prime }$ effect
• Charged Higgs Contribution on B_c decays into (D_s,D_s^*)l^+ l^-
• The Study of Rare $B_c\to D_{s,d}^{(\ast )}l\bar{l}$ Decays
• Exploring New Physics in transition $b\to s{\ell }^{+}{\ell }^{-}$ through different $B_c\to D_s^{(\ast )}{\ell }^{+}{\ell }^{-}$ observables
• $B_c$ to $A$ Transition Form Factors and Semileptonic Decays in Self-consistent Covariant Light-front Approach
• Decay $B_c^{+}\to D_{(s)}^{(\ast )+}{\ell }^{+}{\ell }^{-}$ within covariant confined quark model