Probing Flavor Physics in BSM Scenarios with SM Null Tests

Abstract

As direct searches for new physics (NP) beyond the standard model (SM) at the LHC and other colliders have so far come up empty, increasingly attention has been paid to the intensity frontier, where high-precision measurements can probe rare processes which are possibly sensitive to indirect signals of NP. An important tool in the quest for NP effects on rare processes is the null tests of the SM. These are observables which vanish or are very small in the SM and which therefore could receive potentially large contributions from NP. Among such tests are, to be discussed here, asymmetries in the charm-meson decays \(D\rightarrow P_1 P_2\ell ^+\ell ^-\) \((P=\pi ,K\) and \(\ell =e,\mu )\), direct CP asymmetries in Cabibbo-favored nonleptonic charm-meson decays, muon asymmetries in the hyperon decay \(\varSigma ^+\rightarrow p\mu ^+\mu ^-\), and searches for the rare transitions \(b\rightarrow ss\bar{d},dd\bar{s}\) and for nonleptonic \(B_s\)-meson decays which fully break isospin symmetry. These are under ongoing or near-future investigations in the LHCb and other experiments.