Exploring charm decays with missing energy in leptoquark models

We investigate the possibility that scalar leptoquarks generate consequential effects on the flavor-changing neutral-current decays of charmed hadrons into final states with missing energy (is not an element of) carried away by either standard model or sterile neutrinos. We focus on scenarios involving the R-2, (R) over tilde (2), and (S) over bar (1) leptoquarks and take into account various pertinent constraints, learning that meson-mixing ones and those inferred from collider searches can be of significance. We find in particular that the branching fractions of charmed meson decays D -> M is not an element of, M = pi, rho, and D-s -> K(*)is not an element of and singly charmed baryon decays Lambda(+)(c) -> p is not an element of and Xi(c) -> Sigma is not an element of are presently allowed to attain the 10(-7)-10(-6) levels if induced by R-2 and that the impact of (R) over tilde (2) is comparatively much less. In contrast, the contributions of (S) over bar (1), which couples to right-handed up-type quarks and the sterile neutrinos, could lead to branching fractions as high as order 10(-3). This suggests that these charmed hadron decays might be within reach of the BESIII and Belle II experiments or future super charm-tau factories and could serve as potentially promising probes of leptoquark interactions with sterile neutrinos.

Automated summary

The study investigates the impact of scalar leptoquarks on flavor-changing neutral-current decays of charmed hadrons, focusing on scenarios involving R-2, (R)tilde(2), and (S)bar(1) leptoquarks. The findings suggest that the branching fractions induced by R-2 may reach levels of 10(-7)-10(-6), while the effect of (R)tilde(2) is relatively weaker. Contributions from (S)bar(1) could lead to branching fractions up to 10(-3), indicating that these decays might be accessible to future experiments and serve as probes of leptoquark interactions with sterile neutrinos.