In the wake of exploring uncertainty in the full angular distribution of the B → Kπ + µ + µ − decay caused by the presence of the intermediate scalar K * 0 meson, we perform the straightforward calculation of the B(Bs) → S (S is a scalar meson) transition form factors in the full kinematical region within the covariant quark model. We restrict ourselves to the scalar mesons below 1 GeV: a0(980), f0(500), f0(980), and K * 0 (800). As an application of the obtained results we calculate the widths of the semileptonic and rare decays B(Bs) → Sℓν, B(Bs) → Sℓl and B(Bs) → Sνν. We compare our results with those obtained in other approaches.Recently, much attention has been paid to the rare flavor-changing neutral current decay B → K * (→ Kπ)µ + µ − . One of the reasons for this was the first measurement of form-factor-independent angular observables performed by the LHCb Collaboration [1,2]. It has been claimed that there is a 3.7σ deviation from the Standard Model (SM) prediction for one of the angular observables. Much effort has been spent to explain this deviation by invoking the effects of new physics (NP) (for example, see Refs. [3][4][5][6][7][8][9] and references therein). The main emphasis of the above-mentioned papers was on the search for the physical observables that have low sensitivity to the form factors.In addition to the NP effects, the uncertainties related to the presence of the intermediate scalar resonance K * 0 decaying into Kπ have been intensively discussed in the literature [10][11][12][13][14][15][16]. A detailed analysis of the B → K * J (→ Kπ)µ + µ − decay in the higher kaon resonance region was done in Ref. [10]. In many papers, the Breit-Wigner form for the Kπ mass spectra was used. However, this assumption cannot be justified for the broad scalar resonances like the K * 0 (800) meson. The improvement of the description was done in Ref.[11] by invoking the chiral perturbation theory for the Kπ interaction. This issue was also generalized to B s → Kπℓν in Ref. [12].As is well-known, short-distance physics is under control in the description of the rare B decays, whereas the effects of long-distance physics described by the hadronic form factors lead to large uncertainties since they involve nonperturbative QCD. The calculation of the B → K * transition form factors have been performed in many theoretical approaches and models. We must mention some of them: light-cone QCD sum rules [17], QCD sum rules [18], the lattice-constrained dispersion quark model [19], the simple dipole parametrization [20], perturbative QCD at large recoil region [21], the relativistic quark model [22], and the Dyson-Schwinger equations in QCD [23].The B s and D s to K * 0 (1430) transition form factors were calculated in Ref. [27] within an approach based on QCD sum rules. The form factors for the B → K * 0 (1430) transition have been evaluated in the light-front quark model [28]. The form factors of rare B → K * 0 (1430)ℓ + ℓ − decay were calculated in Ref. [29] within three-point QCD sum rules. The B → S transition...
The burning kinetics of dense hot plasma of composition D+D, D+T, D+ 3 He in devices with inertial-magnetic confinement concept is considered. Calculations of the burning kinetics of main fusion reactions in plasma with use of modern refined data on reaction rates at the appropriate temperatures and several types of energy loss for radiation have been made. An analysis of the energy yield is performed taking into account the change in plasma temperature and the heating of burning area in equilibrium plasma, which is described by Maxwell distribution, as well as the analysis of energy exchange between two adjacent burning volumes with different temperatures. Based on all the data found, estimates of the burning properties of plasma in thermonuclear devices with inertial-magnetic confinement of plasma have been made.
Nuclear gamma-resonance spectroscopy on 57Fe nuclei, X-ray diffraction, and scanning electron microscopy have been used to study the narrow fractions of fly ash formed after combustion of the Ekibastuz coal. Two groups of samples of magnetic (ferrospheres) and non-magnetic type have been separated by granulometric and magnetic separation. A number of regularities associated with the granules size of fly ash have been established. According to the data of Mössbauer spectroscopy, a decrease in the magnetically ordered contribution has been identified with the growth of the particle size. After magnetic separation, iron in ferrospheres was found mainly in the structure of Fe3O4/γ-Fe2O3 and α-Fe2O3. The dominant phase was Fe3O4 (60–77%), the amount of which decreases with the growth of the grain size. With the growth of the particle size, the ratio of [Fe]tetra/[Fe]octa positions occupancy in Fe3O4 approaches 0.5; the structure of magnetite tends to the stoichiometric composition. α-Fe was found in the composition of ferrospheres, and a mechanism of its formation was proposed. The main components of the non-magnetic fractions of fly ash are mullite, hercynite, and silicate glass.
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