Samuel Bertolini

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We use the chiral quark model to construct the complete O(p2) weak ∆S = 1 chiral lagrangian via the bosonization of the ten relevant operators of the effective quark lagrangian. The chiral coefficients are given in terms of fπ, the quark and gluon condensates and the scale-dependent NLO Wilson coefficients of the corresponding operators; in addition, they(More)
We discuss a new estimate of ε/ε in the kaon system. The present approach is based on the evaluation of the hadronic matrix elements of the ∆S = 1 effective quark lagrangian by means of the chiral quark model, with the inclusion of meson one-loop renormalization and NLO Wilson coefficients. The estimate here reviewed is fully consistent with the ∆I = 1/2(More)
The precipitation of lithium sulfide (Li2S) on the Li metal anode surface adversely impacts the performance of lithium-sulfur (Li-S) batteries. In this study, a first-principles approach including density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations is employed to theoretically elucidate the Li2S/Li metal surface interactions(More)
After updating the determination of the combination of Kobayashi-Maskawa elements ImVtdV ∗ ts according to our new estimate of the parameter B̂K , we study the CP -violating ratio ε/ε by means of hadronic matrix elements computed to O(p) in the chiral expansion. It is the first time that this order in chiral perturbation theory is included. We also discuss(More)
We calculate the hadronic matrix elements to O(p) in the chiral expansion for the (∆S = 1) K → 2 π decays and the (∆S = 2) K̄-K oscillation. This is done within the framework of the chiral quark model. The chiral coefficients thus determined depend on the values of the quark and gluon condensates and the constituent quark mass. We show that it is possible(More)
We study the effect of supersymmetric contributions to the effective quark transition b → sγγ, including leading order QCD effects. We apply the discussion to the decay Bs → γγ. In all generality the amplitude for the two-photon emission is strongly correlated to the b → sγ amplitude which is sharply constrained by experiment. A quite general statement(More)
We compute the B̂K parameter and the mass difference ∆MLS of the K 0-K̄0 system by means of the chiral quark model. The chiral coefficients of the relevant ∆S = 2 and ∆S = 1 chiral lagrangians are computed via quark-loop integration. We include the relevant effects of one-loop corrections in chiral perturbation theory. The final result is very sensitive to(More)
After updating the determination of the combination of Kobayashi-Maskawa elements Im V ∗ tsVtd according to a new estimate of the parameter B̂K , we study the CP -violating ratio ε/ε by means of hadronic matrix elements computed to O(p4) in the chiral expansion and NLO Wilson coefficients. It is the first time that this order in chiral perturbation theory(More)
We compute the B̂K parameter and the mass difference ∆MLS of the K 0-K̄0 system by means of the chiral quark model. The chiral coefficients of the relevant ∆S = 2 and ∆S = 1 chiral lagrangians are computed via quark-loop integration. We include the relevant effects of one-loop corrections in chiral perturbation theory. The final result is very sensitive to(More)
I discuss the comparison of the current theoretical calculations of ε/ε with the experimental data. Lacking reliable “first principle” calculations, phenomenological approaches may help in understanding correlations among different contributions and available experimental data. In particular, in the chiral quark model approach the same dynamics which(More)
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