Counting Inclusive b Jets as an Efficient Probe of New Flavor Physics

We consider the inclusive reaction ℓ⁺ℓ^-→nb+X ( n = number of b jets) in lepton colliders for which we propose a useful approximately conserved quantum number b_P = (-1)ⁿ that we call b parity ( b_P). We make the observation that the standard model (SM) is essentially b_P even since SM b_P-violating signals are necessarily Cabibbo-Kobayashi-Maskawa suppressed. In contrast new flavor physics can produce b_P = -1 signals whose only significant SM background is due to b-jet misidentification. Thus, we show that b-jet counting, that relies primarily on b tagging, becomes a very simple and sensitive probe of new flavor physics (i.e., of b_P violation).