Rare meson decay through off-shell doubly charged scalars

Abstract

The presence of charged scalars is almost inevitable in most of the beyond standard model scenarios. They are expected to be detected easily if they are there due to their electromagnetic charge. These charged scalars can be produced at the LHC and their decays may lead to interesting signals-multilepton final states, displaced vertices, etc. These charged particles also play crucial roles in low energy rare processes. Thus apart from the collider searches in low energy rare processes their presence can be smelled. Here, we have noted the impact of doubly charged scalars in rare meson decays. As the mesons are lighter these heavy scalars always appear off shell. Due to their off-shell structure the phase space is relatively complicated to deal with. In this paper we have supplemented a general proposal to compute these decays that involve off-shell doubly charged scalars. We have argued that our prescription can be used for any process involving off-shell heavy scalars. Using the prescribed method we have computed two possible meson decays: M ± -► I f l j M '11, M ± -» I f ljlfJ n M '^. We have also estimated the numerical values of the branching ratios in different channels for different charged mesons.

Doubly-charged scalar in rare decays of the Bc meson

“…We can estimate this as follows: from Eqs. (6) and (15) one can see that the ratio of the constants is ð2 6 π 3 Þ −1 ¼ 5.0 × 10 −4 , which provide most of the difference between Table I and II. The channels which have the largest upper limit are J=ψD Ãþ s l − l − , which are about 10 −28 .…”

“…Theoretically, the heavy bosons cannot on the mass shell, their contribution is reflected in effective interaction vertices [10]. Such low energy processes include the rare decays of top quark [11], τ lepton [11][12][13], or charged mesons [10,14,15]. Surely the branching ratios of these decay modes will be very small due to the large Higgs mass and small coupling constant.…”

Hilbert series and plethystics: paving the path towards 2HDM- and MLRSM-EFT

“…So MLRSM-EFT scenario offers very convoluted contributions to 0ν2β process, and the usual constraints need to be revisited. The leptonic current for this process, and the meson decays (M + → M − l + l + ) are the same [247][248][249][250]. Thus the prediction for meson decays through Majorana neutrinos and doubly charged scalars will also be modified.…”

Novel method to deal with off-shell particles in cascade decays

“…The first example follows from Ref. [3] where an outline of the algorithm was given for scalar propagators only. Consider the decay of a heavy lepton 0 to three leptons 1 , 2 , and 3 , mediated by scalars which we will call ∆.…”