Testing the W-exchange mechanism with two-body baryonic B decays

Abstract

The role of $W$-exchange diagrams in baryonic $B$ decays is poorly understood, and often taken as insignificant and neglected. We show that charmful two-body baryonic $B\to {\mathbf{B}}_c{\bar{\mathbf{B}}}^{\prime }$ decays provide a good test-bed for the study of the $W$-exchange topology, whose contribution is found to be non-negligible; here ${\mathbf{B}}_c$ is an anti-triplet or a sextet charmed baryon, and ${\bar{\mathbf{B}}}^{\prime }$ an octet charmless (anti-)baryon. In particular, we calculate that $\mathcal{B}({\bar{B}}^0\to {\Sigma }_c^{+}\bar{p})=(2.9_{-0.9}^{+0.8})\times 10^{-6}$ in good agreement with the experimental upper bound. Its cousin ${\bar{B}}_s^0$ mode, ${\bar{B}}_s^0\to {\Lambda }_c^{+}\bar{p}$, is a purely $W$-exchange decay, hence is naturally suited for the study of the role of the $W$-exchange topology. We predict $\mathcal{B}({\bar{B}}_s^0\to {\Lambda }_c^{+}\bar{p})=(0.8\pm 0.3)\times 10^{-6}$, a relatively large branching ratio to be tested with a future measurement by the LHCb collaboration. Other predictions, such as $\mathcal{B}({\bar{B}}^0\to {\Xi }_c^{+}{\bar{\Sigma }}^{-})=(1.1\pm 0.4)\times 10^{-5}$, can be tested with future Belle II measurements.

12 pages, 1 figure, 3 tables, version published in JHEP

References in corpus (6)

• ${\Lambda }_c\to \Lambda {\ell }^{+}{\nu }_{\ell }$ form factors and decay rates from lattice QCD with physical quark masses
• Partial waves of baryon-antibaryon in three-body B meson decay
• Violation of PCAC and two-body baryonic $B$ and $D_s$ decays
• Enhanced $B\to \mu \bar{\nu }$ Decay at Tree Level as Probe of Extra Yukawa Couplings
• Baryonic D Decay $D_s^{+}\to p\bar{n}$ and Its Implication
• Study of $B^{-}\to \Lambda \bar{p}{\eta }^{{(}^{\prime })}$ and ${\bar{B}}_s^0\to \Lambda \bar{\Lambda }{\eta }^{{(}^{\prime })}$ decays

Cited by in corpus (13)

• Charmed ${\Omega }_c$ weak decays into $\Omega$ in the light-front quark model
• Estimates of exchange topological contributions and $CP$-violating observables in ${\Lambda }_b\to \Lambda \varphi$ decay
• Study of two-body doubly charmful baryonic $B$ decays with $SU(3)$ flavor symmetry
• Baryonic $B$ meson decays
• Search for the rare hadronic decay $B_s^0\to p\bar{p}$
• Topological $SU(3{)}_f$ approach for two-body ${\Omega }_c$ weak decays
• Two-body Baryonic $B_{u,d,s}$ and $B_c$ to Charmless Final State Decays
• Semileptonic baryonic $B$ decays
• Angular asymmetries in $B\to \Lambda \bar{p}M$ decays
• Charmful two-body ${\Omega }_b$ decays in the light-front quark model
• Hidden charm ${\mathcal{P}}_{cs}(4338{)}^0$ production in baryonic $B^{-}\to J/\psi \Lambda \bar{p}$ decay
• First observation of the ${\overline{B}}_s^0\to {\Lambda }_c^{+}{\overline{\Lambda }}_c{}^{-}$ decay and evidence for the ${\overline{B}}^0\to {\Lambda }_c^{+}{\overline{\Lambda }}_c{}^{-}$ decay
• Rescattering-induced $D\to SS$ weak decays