Model-independent constraints on ΔF = 2 operators and the scale of new physics

By M. Bona, Marco Ciuchini, E. Franco, V. Lubicz, G. Martinelli, F. Parodi, M. Pierini, P. Roudeau, C. Schiavi, L. Silvestrini and 3 more. 2007

566 citations recorded by the source corpus.

We update the constraints on new-physics contributions to ΔF = 2 processes from the generalized unitarity triangle analysis, including the most recent experimental developments. Based on these constraints, we derive upper bounds on the coefficients of the most general ΔF = 2 effective Hamiltonian. These upper bounds can be translated into lower bounds on the scale of new physics that contributes to these low-energy effective interactions. We point out that, due to the enhancement in the renormalization group evolution and in the matrix elements, the coefficients of non-standard operators are much more constrained than the coefficient of the operator present in the Standard Model. Therefore, the scale of new physics in models that generate new ΔF = 2 operators, such as next-to-minimal flavour violation, has to be much higher than the scale of minimal flavour violation, and it most probably lies beyond the reach of direct searches at the LHC.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/1f8cbc341dae573c8796e6b603bdd320fed595ab

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Citations in the corpus

Non-resonant new physics in top pair production at hadron colliders (2010, background): “We have discarded the operator ( Q̄TγqL ) ( Q̄TγqL ) as well as its SU(2) triplet and color singlet1 analogues since they are already strongly constrained by flavour physics [40].”
Vectorlike confinement at the LHC (2009, background): “The absence of FCNCs then requires the coefficients of these operators be <∼ (O(105) TeV)−2 [19].”
Low scale flavor gauge symmetries (2010, background): “At tree level the strongest bounds come from ∆F = 2 quark transitions, whose bounds on 4-fermion operators are conveniently summarized in [41].”
Reconsidering the one leptoquark solution: flavor anomalies and neutrino mass (2017, unknown): “[118], our leptoquark only generates the effective operator Q 1 = C bs 1 (q̄ α i γμPLq α j )(q̄ β i γ PLq β j ), where α and β are color indices, through box diagrams with neutrinos and leptoquarks in the loop.”
Implications of LHCb measurements and future prospects - eScholarship (2013, methodology): “1)◦ [262] and not using the measurement of 2βs from b → cc̄s decays.”
The flavor of the composite pseudo-goldstone Higgs (2008, methodology): “The Wilson coefficients of these operators will directly correspond to the C1,4,5 bounded by the model independent constraints from ∆F = 2 processes by the UTFit collaboration3 in [11], see table 2.”