arXiv subjects
Publications and source records attributed to M. I. Vysotsky.
Precise measurements of Z-boson parameters and W-boson and t-quark masses put strong constraints on non SU(2) * U(1) singlet New Physics. We demonstrate that one extra generation passes electroweak constraints even when all new particle masses are well above their direct mass bounds.
Precision measurements of $Z$-boson parameters and $W$-boson and $t$-quark masses put strong constraints on non $SU(2)\times U(1)$ singlet New Physics. We demonstrate that one extra generation passes electroweak constraints even when all new particle masses are well above their direct mass bounds.
Arguments coming from Quantum Field Theory are supplemented with a 1-loop perturbative calculation to settle the non-unitarity of mixing matrices linking renormalized mass eigenstates to bare flavor states for non-degenerate coupled fermions. We simultaneously diagonalize the kinetic and mass terms and counterterms in the renormalized Lagrangian. SU(2)_L gauge invariance constrains the mixing matrix in charged currents of renormalized mass states, for example the Cabibbo matrix, to stay unitary. Leaving aside CP violation, we observe that the mixing angles exhibit, within experimental uncertainty, a very simple breaking pattern of SU(2)_f horizontal symmetry linked to the algebra of weak neutral currents, the origin of which presumably lies beyond the Standard Model. It concerns: on one hand, the three quark mixing angles; on the other hand, a neutrino-like pattern in which theta_{23} is maximal and tan(2 theta_{12})=2. The Cabibbo angle fulfills the condition tan (2 theta_c)=1/2 and theta_{12} for neutrinos satisfies accordingly the "quark-lepton complementarity condition" theta_c + theta_{12}= π/4. theta_{13} = +- 5.7 10^{-3} are the only values obtained for the third neutrino mixing angle that lie within present experimental bounds. Flavor symmetries, their breaking by a non-degenerate mass spectrum, and their entanglement with the gauge symmetry, are scrutinized; the special role of flavor rotations as a very mildly brokensymmetry of the Standard Model is outlined.
The final state interactions (FSI) model, in which soft rescattering of low mass intermediate states dominate, is suggested. It explains why the strong interaction phases are large in the $B_d\toππ$ channel and are considerably smaller in the $B_d\toρρ$ one.
General formulas as well as leading asymptotics for corrections to Z- and W-boson parameters are derived. Experimental data fits in Standard Model and its extensions are discussed and results are presented.
Loop corrections induce a dependence on the momentum squared of the coefficients of the Standard Model Lagrangian, making highly non-trivial (or even impossible) the diagonalization of its quadratic part. Fortunately, the introduction of appropriate counterterms solves this puzzle.
The effects of final state interactions (FSI) in hadronic B-decays are investigated. The model for FSI, based on Regge phenomenology of high-energy hadronic interactions is proposed. It is shown that this model explains the pattern of phases in matrix elements of $B\toππ$ and $B\toρρ$ decays. These phases play an important role for CP-violation in B-decays. The most precise determination of the unitarity triangle angle $α$ from $B_d\to ρπ$ decays is performed. The relation between CP-asymmetries in $B\to Kπ$ decays is discussed. It is emphasized that the large distance FSI can explain the structure of polarizations of the vector mesons in B-decays and other puzzles like a very large branching ratio of the B-decay to $\barΞ_cΛ_c$.
We investigate the implications of the model with a SU(2)-singlet up-type quark, heavy enough not to be produced at the LHC, namely, the contribution of the new quark to the branching ratios of the K to πν\barν, B to πν\barν and B to K ν\barν decays. We show that the deviation from the Standard Model can be up to 10% in the case of a 5 TeV quark. Precise measurements of these branching ratios at the future experiments will allow to observe the contributions of the new quark or to impose stronger constraints on its mass.
The final state interactions (FSI) model in which soft rescattering of low mass intermediate states dominates is suggested. It explains why the strong interaction phases are large in the $B_d\toππ$ channel and are considerably smaller in the $B_d\toρρ$ one. Direct CP asymmetries of $B_d\toππ$ decays which are determined by FSI phases are considered as well.
A simple extension of the Standard Model demonstrates that New Physics non-reachable through direct production at LHC can induce up to 10% corrections to the length of the unitarity triangle side, extracted from $Δm_{B_d}$.
Theoretically motivated smallness of the penguin amplitude in $B \to ππ$ decays allowes to calculate the value of the unitarity triangle angle $α(ϕ_2)$ with good accuracy. The relatively large branching ratio of the decay into $π^0 π^0$ is explained by the large value of FSI phase difference between $ΔI = 1/2$ and $ΔI = 3/2$ tree amplitudes.
The hypothesis of the smallness of penguin contribution to charmless strangeless $B_d (\bar B_d)$ decays allows to determine with high accuracy the value of angle $α$ from the currently available $B \to ρρ$, $B \to ππ$ and $B\to ρπ$ decay data.
We determine the domains of the values of unitarity triangle angle alpha, allowed by the charmless strangeless B_d (\bar B_d) decays.
The difference between induced by box diagram quantity \tilde εand experimentally measured value of εis determined and used to obtain the value of \tilde εwith high precision. Present day knowledge of CKM matrix elements (including B-factory data), allows us to obtain from the Standard Model expression for \tilde εthe value of parameter B_K: B_K = 0.89 \pm0.16. It turns out to be very close to the result of vacuum insertion, B_K = 1.
Quasi-degenerate binary systems of neutral mesons of the kaon type are investigated in Quantum Field Theory (QFT). General constraints cast by analyticity and discrete symmetries P, C, CP, TCP on the propagator (and on its spectral function) are deduced. Its poles are the physical masses; this unambiguously defines the propagating eigenstates. It is diagonalized and its spectrum thoroughly investigated. The role of ``spurious'' states, of zero norm at the poles, is emphasized, in particular for unitarity and for the realization of TCP symmetry. The K_L-K_S mass splitting triggers a tiny difference between their CP violating parameters ε_L and ε_S, without any violation of TCP. A constant mass matrix like used in Quantum Mechanics (QM) can only be introduced in a linear approximation to the inverse propagator, which respects its analyticity and positivity properties; it is however unable to faithfully describe all features of neutral mesons as we determine them in QFT, nor to provide any sensible parameterization of eventual effects of TCP violation. The suitable way to diagonalize the propagator makes use of a bi-orthogonal basis; it is inequivalent to a bi-unitary transformation (unless the propagator is normal, which cannot occur here). Problems linked with the existence of different ``in'' and ``out'' eigenstates are smoothed out. We study phenomenological consequences of the differences between the QFT and QM treatments. The non-vanishing of semi-leptonic asymmetry δ_S - δ_L does not signal, unlike usually claimed, TCP violation, while A_TCP keeps vanishing when TCP is realized. We provide expressions invariant by the rephasing of K0 and K0bar.
The higher bound on the mass of the Brout-Englert-Higgs scalar boson (BEH boson for brevity) arising from radiative corrections is not stable when the Standard Model is extended to include non-decoupling particles. In particular additional generation{s} of fermions allow for a heavier scalar. We investigate how the decay branchings of scalar boson are affected by the opening of new channels.
The difference between induced by box diagram value of \tilde εand experimentally measured value of εis estimated. It appeared to be around 5 - 10 %, depending on the values of hadronic matrix elements. With this result, the fit of CKM marix parameters within the SM is performed.
We consider a few thought experiments of radial motion of massive particles in the gravitational fields outside and inside various celestial bodies: Earth, Sun, black hole. All other interactions except gravity are disregarded. For the outside motion there exists a critical value of coordinate velocity ${\rm v}_c = c/\sqrt 3$: particles with ${\rm v} < {\rm v}_c$ are accelerated by the field, like Newtonian apples, particles with ${\rm v} > {\rm v}_c$ are decelerated like photons. Particles moving inside a body with constant density have no critical velocity; they are always accelerated. We consider also the motion of a ball inside a tower, when it is thrown from the top (bottom) of the tower and after classically bouncing at the bottom (top) comes back to the original point. The total time of flight is the same in these two cases if the initial proper velocity $v_0$ is equal to $c/\sqrt 2$.