Flavor physics at the EIC with b -jet tagging

We employ an approximate conserved quantum number [defined as “ b parity” in ] of the Standard Model (SM): b P = ( − 1 ) n , where n is the number of produced b jets in the reaction e + p / A → n · j b + X , to explore new TeV-scale flavor-changing interactions involving the third-generation quarks at the Electron-Ion Collider (EIC); simply by counting the number of b jets in the final state. In particular, the SM single and dijet production at the EIC, which occurs through charge current interactions, e + p / A → j + E T and e + p / A → 2 · j + E T , are b P even since the b P -violating (i.e., b P = − 1 ) SM signals for these processes are necessarily Cabibbo-Kobayashi-Maskawa suppressed and, therefore, have a vanishingly small production rate. In contrast, new flavor physics can generate b P = − 1 signals at the EIC whose only significant SM background is due to b -jet misidentification. We thus show that b P can be used as a simple and sensitive probe of new flavor-violating physics; specifically, we find that counting single b -jet events in e + p / A → j + E T at the EIC with a center-of-mass (c.m.) energy of s ∼ 140 GeV can probe scales of new physics up to Λ ≲ O ( 5 ) TeV for a certain type of new chiral flavor-changing physics in third-generation interactions. This is remarkably more than 30 times larger than the assumed EIC c.m. energy and it critically depends on the b -tagging efficiency and purity as well as the feasibility of electron beam polarization. The sensitivity of the dijet process, e + p / A → 2 j + E T , to these