Astrophysical <Emphasis Type="Italic">S</Emphasis>-factor of the <Emphasis Type="Italic">p</Emphasis><Superscript>9</Superscript>Be → <Superscript>10</Superscript>Bγ radiative capture

The S-factor of the p ⁹Be → ¹⁰Bγ radiative capture is considered at astrophysical energies in the potential cluster model where orbital states are classified by the Young schemes.     

Astrophysical <Emphasis Type="Italic">S</Emphasis>-factor for the radiative-capture reaction <Emphasis Type="Italic">p</Emphasis><Superscript>13</Superscript>C → <Superscript>14</Superscript>N<Emphasis Type="Italic">γ</Emphasis>

The possibility of describing experimental data on the astrophysical S factor for radiative proton capture on a ¹³C nucleus at energies in the range 0.03–0.8 MeV is considered within the potential cluster model involving forbidden states. It is shown that the energy dependence of this astrophysical S factor can be reasonably explained on the basis of the E1 transition to the ³ P ₁-wave bound state of the ¹⁴N nucleus in the p ¹³C channel from the ³ S ₁ wave of p ¹³C scattering in the resonance energy region around 0.55 MeV in the laboratory frame.     

Near-threshold radiative 3<Emphasis Type="Italic">π</Emphasis> production in <Emphasis Type="Italic">e</Emphasis><Superscript>+</Superscript><Emphasis Type="Italic">e</Emphasis><Superscript>−</Superscript> annihilation

We consider the π⁺π^?π₀γ final state in electron-positron annihilation at c.m.s. energies not far from the threshold. Both initial-and final-state radiations of the hard photon are considered, but without interference between them. The amplitude for the final-state radiation is obtained by using the effective Wess-Zumino-Witten Lagrangian for pion-photon interactions valid for low energies. In real experiments, energies are never so small that ρ and ω mesons would have a negligible effect. So a phenomenological Breit-Wigner factor is introduced in the final-state radiation amplitude to account for the vector mesons' influence. Using radiative 3π production amplitudes, a Monte Carlo event generator was developed which could be useful in experimental studies.     

Nuclear asymptotic normalization coefficients for <Superscript>14</Superscript>N → <Superscript>13</Superscript>C + <Emphasis Type="Italic">p</Emphasis> configurations and astrophysical <Emphasis Type="Italic">S</Emphasis> factor for radiative proton capture

Empirical values of the asymptotic normalization coefficient for proton bound states in the ¹⁴N nucleus for the first five levels were obtained from an analysis of the experimental differential cross sections known from our measurements and from the literature for the reaction ¹³C(³He, d)¹⁴N in the projectile-energy range between about 15 and 40 MeV. The values obtained in this way were used to calculate the astrophysical S factors for the reaction ¹³C(p, γ)¹⁴N in the case of the population of the first five levels of the 14N nucleus. The calculations were based on the R-matrix approach. The calculated values are in good agreement with the experimental astrophysical S factor at energies below 1 MeV.     

Astrophysical <Emphasis Type="Italic">S</Emphasis>-factor of the <Emphasis Type="Italic">p</Emphasis><Superscript>7</Superscript>Li → <Superscript>8</Superscript>Beγ capture at low energies

The interaction potentials describing some phases of elastic p ⁷Li scattering for energies up to 0.8 MeV and the ground bound P ₀ state of the ⁸Be nucleus in the p ⁷Li cluster channel are obtained. The astrophysical S-factor of the p ⁷Li → ⁸Beγ radiative capture is considered for the potential cluster model.     

Astrophysical <Emphasis Type="Italic">S</Emphasis> factor for the radiative-capture reaction <Emphasis Type="Italic">p</Emphasis><Superscript>6</Superscript>Li → <Superscript>7</Superscript>Beγ

A new measurement of differential cross sections for elastic p ⁶Li scattering in the energy range 0.35–1.2 MeV was performed. A partial-wave analysis of the data obtained in this way was carried out, and potentials simulating the p ⁶Li interaction were constructed. Various experiments devoted to studying elastic p ⁶Li scattering over the broad energy range of 0.5–50 MeV were analyzed on the basis of the optical model. By using the potentials obtained from the partial-wave analysis, the possibility of describing the astrophysical S factor for radiative proton capture on ⁶Li at low energies was considered within the potential cluster model involving forbidden states.     

Bottomonium γ(5<Emphasis Type="Italic">S</Emphasis>) decays into <Emphasis Type="Italic">BB</Emphasis> and <Emphasis Type="Italic">BB</Emphasis>π

Two-and three-body decays of γ(5S) into BB, BB*, B*B*, B _s B _s , B _s B _s ^*, and BB*π, B*B*π are evaluated using the theory developed earlier for dipion-bottomonium transitions. The theory contains only two parameters—vertex masses M _br and M _ω—known from the dipion spectra and width. Predicted values of Γ_tot(5S) and six partial widths Γ _k (5S), k = BB, BB*, ... are in agreement with the experiment. The decay widths Γ_5S (πBB*) and Γ_5S (πB*B*) are also calculated and found to be on the order of 10 keV. The text was submitted by the authors in English.     

On mass corrections to the decay <Emphasis Type="Italic">P</Emphasis> → <Emphasis Type="Italic">l</Emphasis><Superscript>+</Superscript><Emphasis Type="Italic">l</Emphasis><Superscript>−</Superscript>

The Mellin-Barnes representation is used to improve the theoretical estimate of mass corrections to the width of a light pseudoscalar meson decay into a lepton pair, P → l ⁺ l ⁻. The full resummation of the terms ln(m _l ²/Λ²)(m _l ²/Λ²) ⁿ and (m _l ²/Λ²) ⁿ to the decay amplitude is performed, where m _l is the lepton mass and Λ ≈ m _ρ is the characteristic scale of the P → γ*γ* form factor. The total effect of the mass corrections for the e ⁺ e ⁻ channel is negligible and, for the μ⁺μ⁻channel, its order is of a few percent. The text was submitted by the authors in English.     

Estimating of CP-violation in <Emphasis Type="Italic">B</Emphasis><Superscript>0</Superscript>→ψ(2<Emphasis Type="Italic">S</Emphasis>)π<Superscript>0</Superscript> decay

I present estimates of CP-violating asymmetries in the non-leptonic charmonium two-body B⁰→ψ(2S)π⁰ decay and the same decays of B⁺→ψ(2S)π⁺ and B⁺→ψ(2S)K⁺ These estimates are based on QCD and improved QCD factorization approach making use of next-to-leading order (NLO) contributions. The CP-violating asymmetry for B⁰→ψ(2S)π⁰ decay is not available, according to the same calculations, it is expected if it can be measured in the future its value will be S_ψ(2S)π0(B⁰ → ψ(2S)π⁰)= 0.662 ± 0.197 and C_ψ(2S)π0(B⁰ → ψ(2S)π⁰)= 0.024 ± 0.007.     

Scalar mesons in <Emphasis Type="Italic">η</Emphasis>′ → <Emphasis Type="Italic">ηπ</Emphasis><Superscript>0</Superscript><Emphasis Type="Italic">π</Emphasis><Superscript>0</Superscript> decay

The decay η′ → ηπ ⁰ π ⁰ is studied in the framework of isobar model. It is shown, that good agreement with the experiment is achieved if α ₀- and σ-meson contributions are taken into account. The contribution of α ₀-meson is dominant, but σ-meson is necessary to reproduce the form of the Dalitz plot. Instead of the usual Breit-Wigner form of σ-meson propagator we use parametrization of the ππ-amplitude, which satisfies analyticity, crossing, unitarity and chirality constraints. This amplitude has a pole in the complex plane, which corresponds to σ-meson and describe experimental data on ππ-scattering in K _e4 decay.     

Lie Superalgebra Structures in <Emphasis Type="Italic">H</Emphasis><Superscript>⋅</Superscript> (<Emphasis Type="Italic">g</Emphasis>;<Emphasis Type="Italic">g</Emphasis>)

Let g=vect(M) be the Lie (super)algebra of vector fields on any connected (super)manifold M; let - be the change of parity functor, C ⁱ and H ⁱ the space of i-chains and i-cohomology. The Nijenhuis bracket makes into a Lie superalgebra that can be interpreted as the centralizer of the exterior differential considered as a vector field on the supermanifold associated with the de Rham bundle on M. A similar bracket introduces structures of DG Lie superalgebra in L ^* and for any Lie superalgebra g. We use a Mathematica-based package SuperLie (already proven useful in various problems) to explicitly describe the algebras l ^* for some simple finite dimensional Lie superalgebras g and their relatives - the nontrivial central extensions or derivation algebras of the considered simple ones.     

Process <Emphasis Type="Italic">γ</Emphasis>*<Emphasis Type="Italic">γ</Emphasis> → <Emphasis Type="Italic">σ</Emphasis> at large virtuality of <Emphasis Type="Italic">γ</Emphasis>*

The process γ*γ → σ is investigated in the framework of the SU(2)×SU(2) chiral NJL model. The form factor of the process is derived for arbitrary virtuality of γ* in the Euclidean kinematic domain. The asymptotic behavior of this form factor resembles the asymptotic behavior of the γ*γ → π form factor.