FCNC B and K meson decays with light bosonic Dark Matter

Abstract

We consider decays of B and K mesons into a pseudo-scalar or vector meson plus missing energy. Within the SM, these modes originate from flavor changing neutral current (FCNC) processes with two neutrinos in the final state. In this paper we consider the experimental upper bounds on these modes and interpret the difference between these bounds and the SM prediction as a window into new light invisible particles. In particular we consider the case where some new symmetry requires the new particles to be produced in pairs. We first construct the general low energy effective Lagrangian coupling an FCNC with two dark sector particles of spin zero, one-half and one. We then present numerical estimates for the constraints that can be placed on these interactions, finding that an effective new physics scale from $$ \mathcal{O} $$ O (10)-$$ \mathcal{O} $$ O (1011) GeV can be probed, with the exact value strongly depending on the interaction structure as well as the mass of the invisible particle. For "Image missing" we incorporate into our constraints the effect of using only the signal regions of NA62, and for "Image missing" the q2-dependent efficiency of Belle II.

The quark flavor-violating ALPs in light of B mesons and hadron colliders

“…Subtracting the SM contributions, ref. [93] derived upper limits on noninterfering new physics contributions, which are reproduced in table 1. We find the constraint on the quantity c…”

“…The invisible decay modes of B mesons and the corresponding measurement or bounds on NP contribution. The upper bounds have been obtained by subtracting the lower bound of the SM prediction from the experimental branching ratio following the procedure in refs [93,94]…”

The dark Stodolsky effect: constraining effective dark matter operators with spin-dependent interactions

“…Finally, the full spin-1 2 basis includes products of fermion bilinears not given in table 1, whilst the complete basis for RS fermions is given in [67]. The same spin-0 basis, along with a similar spin-1 basis can also be found in [81].…”

The first limit on invisible decays of $$B_s$$ mesons comes from LEP

“…The b → s flavor-changing neutral currents, which are strongly suppressed in the Standard Model (SM), have gathered a lot of attention in the past few years. The transition involving neutrinos, b → s νν, is theoretically well-suited to test the consistency of the Standard Model [1][2][3][4][5] and offers a window to weakly-coupled light new physics [6][7][8][9][10][11][12][13][14][15][16][17]. However, the associated B meson decay modes are challenging to test experimentally due to the presence of missing energy in the final state, and until recently only upper limits on the B → K νν channels existed [18][19][20][21].…”