Phenomenological implications of the intrinsic charm in the

In this paper we study the Z, $$Z+$$ jet, $$Z+c$$, and $$Z+c+$$ jet production in pp collisions at the LHC considering different models for the intrinsic charm content of the proton. We analyze the impact of the intrinsic charm in the rapidity and transverse momentum distributions for these different processes. Our results indicated that differently from the other processes, the $$Z+c$$ cross section is strongly affected by the presence of the intrinsic charm. Moreover, we propose the analysis of the ratios $$R(Z+c/Z) \equiv \sigma (Z+c)/\sigma (Z)$$ and $$R(Z+c/Z+\text{ jet }) \equiv \sigma (Z+c)/\sigma (Z+\text{ jet })$$ and we demonstrate that these observables can be used as a probe of the intrinsic charm

Charming new B-physics

We give a comprehensive account of the flavour physics of Beyond-Standard-Model (BSM) effects in b → cc¯¯cs transitions, considering the full set of 20 four-quark operators. We discuss the leading-order structure of their RG mixing with each other as well as the QCD-penguin, dipole, and FCNC semileptonic operators they necessarily mix with, providing compact expressions. We also provide the first complete results for BSM effects in the lifetime observables ∆Γs and τ (Bs)/τ(Bd), as well as for the semileptonic CP-asymmetry assl. From a global analysis, we obtain stringent constraints on 16 of the 20 BSM operators, including the 10 operators Qc′1…10 involving a right-handed strange quark. Focussing on CP-conserving new physics, the constraints correspond to NP scales of order 10 TeV in most cases, always dominated by exclusive and/or radiative B-decays via RGE mixing. For the remaining four operators, including the two Standard-Model (SM) ones, larger effects are experimentally allowed, as previously noted in [1]. We extend that paper’s scope to the CP-violating case, paying attention to the impact on the decay rate and time-dependent CP-violation in Bd → J/ψKS. Contrary to common lore, we show that quantifiable constraints arise for new physics in either of the two SM operators, with the uncertain non-perturbative matrix element of the colour-suppressed (or equivalently, colour-octet) operator determined from the data. For new physics in the coefficient Cc1, suppressed in the SM, we find (in addition to CP-conserving new physics) two perfectly viable, narrow bands of complex Wilson coefficients. Somewhat curiously, one of them contains a region where the fitted matrix element for the colour-suppressed operator is in agreement with naive factorization, contrarily to a widely held belief that large non- factorizable contributions to Bd → J/ψKS are implied by experimental data