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تسجيل مستخدم جديدVector Leptoquarks Beyond Tree Level III: Vector-like Fermions and Flavor-Changing Transitions
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Extending previous work on this subject, we evaluate the impact of vector-like fermions at next-to-leading order accuracy in models with a massive vector leptoquark embedded in the $SU(4)times SU(3)^primetimes SU(2)_Ltimes U(1)_X$ gauge group. Vector-like fermions induce new sources of flavor symmetry breaking, resulting in tree-level flavor-changing couplings for the leptoquark not present in the minimal version of the model. These, in turn, lead to a series of non-vanishing flavor-changing neutral-current amplitudes at the loop level. We systematically analyze these effects in semileptonic, dipole and $Delta F=2$ operators. The impact of these corrections in $bto s u u$ and $bto ctau u$ observables are discussed in detail. In particular, we show that, in the parameter region providing a good fit to the $B$-physics anomalies, the model predicts a $10%$ to $50%$ enhancement of $mathcal{B}(Bto K^{(*)} u u)$.
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