Higher-order QCD corrections to H → b$$ \overline{b} $$ from rational approximants

We use rational approximants to study missing higher orders in the massless scalar-current quark correlator. We predict the yet unknown six-loop coefficient of its imaginary part, related to Γ(H → b$$ \overline{b} $$ b ¯ ), to be c5 = −6900 ± 1400. With this result, the perturbative series becomes almost insensitive to renormalization scale variations and the intrinsic QCD truncation uncertainty is tiny. This confirms the expectation that higher-order loop computations for this quantity will not be required in the foreseeable future, as the uncertainty in Γ(H → b$$ \overline{b} $$ b ¯ ) will remain largely dominated by the Standard Model parameters.

Mixed scalar-current bootstrap in three dimensions

We study the mixed system of correlation functions involving a scalar field charged under a global U(1) symmetry and the associated conserved spin-1 current Jμ. Using numerical bootstrap techniques we obtain bounds on new observables not accessible in the usual scalar bootstrap. We then specialize to the O(2) model and extract rigorous bounds on the three-point function coefficient of two currents and the unique relevant scalar singlet, as well as those of two currents and the stress tensor. Using these results, and comparing with a quantum Monte Carlo simulation of the O(2) model conductivity, we give estimates of the thermal one-point function of the relevant singlet and the stress tensor. We also obtain new bounds on operators in various sectors.

Subleading contributions to the nuclear scalar isoscalar current

We extend our recent analyses of the nuclear vector, axial-vector and pseudoscalar currents and derive the leading one-loop corrections to the two-nucleon scalar current operator in the framework of chiral effective field theory using the method of unitary transformation. We also show that the scalar current operators at zero momentum transfer are directly related to the quark mass dependence of the nuclear forces.

Psuedo-Scalar Current and Weak Type Interaction in Fourth Generation Quarks Models

In this note, the toy-model of Fourth Generation quarks coupling to Standard Model particles through unknown Lagrangian has been figured. Eventually producing a 103 TeV vector gauge boson, which is a special gauge boson that appears in unification models and here as a mediator for WeakSM4 interaction. Another anomaly of different gauge boson has been reported.

b → cℓν anomalies in light of extended scalar sectors

Considering the recent experimental results on exclusive semileptonic [Formula: see text] meson decays showing sizable departure from their Standard Model prediction of lepton flavor universality and keeping ongoing and proposed nonstandard Higgs searches in mind, we explore the charged current flavor observables [Formula: see text], among other [Formula: see text] transitions, in the presence of a relevant scalar current effective new physics operator. We use [Formula: see text] lifetime and predicted bounds on the branching fraction of [Formula: see text] decay as constraints. We show the allowed parameter space in terms of the real and imaginary parts of the corresponding Wilson coefficients for such interactions. Under the light of obtained results, we study the prospect of two benchmark models, rendering the Wilson coefficients real (Georgi–Machacek (GM)) and complex (leptoquark (LQ)), respectively. We show that constraints from [Formula: see text] on GM parameters are consistent with other flavor constraints on the model, if we drop the Babar results. Including those that disfavors the model by more than [Formula: see text]. On the other hand, one benchmark LQ scenario, which gives rise to a single scalar current effective interaction, is still allowed within [Formula: see text] confidence level, albeit with a shrunk parameter space.