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The intramolecular oxidative coupling of electron-rich aromatic groups in 5-(het)aryl-1-(het)arylalkyl-1 H -1,2,3-triazoles was studied in detail. Under treatment with phenyliodoso bis(trifluoroacetate) and boron trifluoride etherate these substrates afforded products of either ortho/ortho or ortho/ipso coupling depending on the nature of aromatic groups and reaction conditions applied. It was found that for substrates which are capable for both types of coupling, ortho-/ipso -adducts are formed under kinetic control while ortho-/ortho -products are formed under thermodynamic control. The developed procedures allow preparation of complex polycyclic azaheterocycles from simple precursors in two steps only.

We present a coupled-channel analysis of the two $$\varSigma \pi $$ charge states and of $$K^-p$$ pair, produced in the reaction $$\gamma p\rightarrow K^+(\varSigma \pi )$$ , and in the reaction $$\gamma p\rightarrow K^+(K^- p)$$ . Hyperon resonances in the mass range from $$\varLambda (1405)1/2^-$$ to the $$\varSigma (1915)5/2^+$$ are produced abundantly in the intermediate state. Cross sections for their production are evaluated.

A measurement of the double-polarization observable E for the reaction $$\gamma p\rightarrow \pi ^0 p$$ γ p → π 0 p is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C$$_4$$ 4 H$$_9$$ 9 OH) target, which provided longitudinally-polarized protons. Circularly-polarized photons were produced via bremsstrahlung of longitudinally-polarized electrons. The data cover the photon energy range from $$E_\gamma =600$$ E γ = 600 to 2310 MeV and nearly the complete angular range. The results are compared to and have been included in recent partial wave analyses.

Data on the beam asymmetry Σ in the photoproduction of η mesons off protons are reported for tagged photon energies from 1130 to 1790 MeV (mass range from W=1748 MeV to W=2045 MeV). The data cover the full solid angle that allows for a precise moment analysis. For the first time, a strong cusp effect in a polarization observable has been observed that is an effect of a branch-point singularity at the pη^{'} threshold [E_{γ}=1447 MeV (W=1896 MeV)]. The latest BnGa partial wave analysis includes the new beam asymmetry data and yields a strong indication for the N(1895)1/2^{-} nucleon resonance, demonstrating the importance of including all singularities for a correct determination of partial waves and resonance parameters.

Low-energy data on the three charge states in $$\gamma p \rightarrow K^+(\varSigma \pi )$$ γ p → K + ( Σ π ) from CLAS at JLab, on $$K^-p\rightarrow \pi ^0\pi ^0\varLambda $$ K - p → π 0 π 0 Λ and $$\pi ^0\pi ^0\varSigma $$ π 0 π 0 Σ from the Crystal Ball at BNL, bubble chamber data on $$K^-p\rightarrow \pi ^-\pi ^+\pi ^{\pm }\varSigma ^{\mp }$$ K - p → π - π + π ± Σ ∓ , low-energy total cross sections on $$K^-$$ K - induced reactions, and data on the $$K^-p$$ K - p atom are fitted with the BnGa partial-wave-analysis program. We find that the data can be fitted well with just one isoscalar spin-1/2 negative-parity pole, the $$\varLambda (1405)$$ Λ ( 1405 ) , and background contributions. In a fit with one isocsalar state, the $$\varLambda (1405)$$ Λ ( 1405 ) structure can be determined as a dominantly SU(3) singlet state. A fit with two isoscalar singlet states, with imposed properties of the low-mass state, is, however, also not incompatible with data.

Data on the beam asymmetry Σ in the photoproduction of η mesons off protons are reported for tagged photon energies from 1130 to 1790 MeV (mass range from W=1748 MeV to W=2045 MeV). The data cover the full solid angle that allows for a precise moment analysis. For the first time, a strong cusp effect in a polarization observable has been observed that is an effect of a branch-point singularity at the pη^{'} threshold [E_{γ}=1447 MeV (W=1896 MeV)]. The latest BnGa partial wave analysis includes the new beam asymmetry data and yields a strong indication for the N(1895)1/2^{-} nucleon resonance, demonstrating the importance of including all singularities for a correct determination of partial waves and resonance parameters.

Recent data on photoproduction of η′ mesons off protons have been included in the data base for the Bonn–Gatchina partial wave analysis. The real and imaginary parts of the S-wave η′p→η′p scattering amplitude in the threshold region were fit to yield the η′p scattering length and the interaction range. This new analysis found |aη′p|=(0.403±0.015±0.060) fm and a phase ϕ=(87±2)∘, while the range parameter is not well-constrained. The striking behavior of the GRAAL data on the beam asymmetry in the threshold region suggests that a narrow proton-η′ resonance might exist. However, the scattering length was found to be relatively insensitive to the possible existence of this narrow resonance.

Photon beam asymmetry Σ measurements for ω photoproduction in the reaction γ → p → ω p are reported for photon energies from 1.152 to 1.876 GeV. Data were taken using a linearly-polarized tagged photon beam, a cryogenic hydrogen target, and the CLAS spectrometer in Hall B at Jefferson Lab. The measurements obtained markedly increase the size of the database for this observable, extend coverage to higher energies, and resolve discrepancies in previously published data. Comparisons of these new results with predictions from a chiral-quark-based model and from a dynamical coupled-channels model indicate the importance of interferences between t-channel meson exchange and s- and u-channel contributions, underscoring sensitivity to the nucleon resonances included in those descriptions. Comparisons with the Bonn–Gatchina partial-wave analysis indicate the Σ data reported here help to fix the magnitudes of the interference terms between the leading amplitudes in that calculation (Pomeron exchange and the resonant portion of the J P = 3 / 2 + partial wave), as well as the resonant portions of the smaller partial waves with J P = 1 / 2 − , 3 / 2 − , and 5 / 2 + .

We report a partial-wave analysis of new data on the double-polarization variable E for the reactions γ p → π + n and γ p → π 0 p and of further data published earlier. The analysis within the Bonn–Gatchina (BnGa) formalism reveals evidence for a poorly known baryon resonance, the one-star Δ ( 2200 ) 7 / 2 − . This is the lowest-mass Δ ⁎ resonance with spin-parity J P = 7 / 2 − . Its mass is significantly higher than the mass of its parity partner Δ ( 1950 ) 7 / 2 + which is the lowest-mass Δ ⁎ resonance with spin-parity J P = 7 / 2 + . It has been suggested that chiral symmetry might be restored in the high-mass region of hadron excitations, and that these two resonances should be degenerate in mass. Our findings are in conflict with this prediction.

To explore the underlying mechanism of cancer cell growth inhibition by brassinosteroids (BS), reactive oxygen species (ROS) generation under treatment with 28-homocastasterone and its synthetic derivatives (22S,23S)-28-homocastasterone was measured in A549 human lung adenocarcinoma cells. BS induced ROS generation in A549 cells and their growth in a time and dose-dependent manner. The maximal effect was observed for (22S,23S)-28-homocastasterone which at 30μM concentration showed a 6-fold increase of ROS generation in comparison with the control.

Early data on $K^-$ induced reactions off protons are collected and used in a coupled-channel partial wave analysis (PWA). Data which had been published in the form of Legendre coefficients are included in the PWA. In a {\it primary} fit using 3* and 4* resonances only, we observe some significant discrepancies with the data. In a systematic search for new $\Lambda$ and $\Sigma$ hyperon resonances, additional candidates are found. The significance of the known and of the additional resonances is evaluated. Seventeen resonances listed with 1* or 2* and one resonance listed with 3* in the Review of Particle Properties cannot be confirmed, five new hyperons are suggested. The partial-wave amplitudes deduced in this analysis are compared to those from other analyses., Comment: 28 pages, 27 figures, 9 Tables

We report properties of $\Lambda$ and $\Sigma$ hyperon resonances formed in $K^-$ induced reactions. Special emphasis is laid on the analysis of the three-body final states $2\pi^0\Lambda$ and $2\pi^0\Sigma$ and of the quasi-two-body final states $\pi\Lambda(1520)$, $\bar K\Delta(1232)$, $\pi\Sigma(1385)$, $\bar K^*N$, and $\omega\Lambda$. We give pole positions of $\Lambda$ and $\Sigma$ hyperon resonances and transition residues from the $K^-p$ initial to various final states as well as Breit-Wigner masses and widths and decay branching ratios. Twenty resonances and "bumps" reported in the Review of Particle Physics are not required in our fits, evidence for five new resonances is reported. The observed mass spectrum is compared to the spectrum calculated in the Bonn quark model. Three spin doublets, six $\Lambda$ hyperons, are tentatively assigned to the SU(3) singlet system., Comment: 18 pages, 10 Figures, 3 Tables

A measurement of the double-polarization observable E for the reaction \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\gamma p\rightarrow \pi ^0 p$$\end{document}γp→π0p is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_4$$\end{document}4H\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_9$$\end{document}9OH) target, which provided longitudinally-polarized protons. Circularly-polarized photons were produced via bremsstrahlung of longitudinally-polarized electrons. The data cover the photon energy range from \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$E_\gamma =600$$\end{document}Eγ=600 to 2310 MeV and nearly the complete angular range. The results are compared to and have been included in recent partial wave analyses.

First measurements of double-polarization observables in ω photoproduction off the proton are presented using transverse target polarization and data from the CEBAF Large Acceptance Spectrometer (CLAS) FROST experiment at Jefferson Lab. The beam-target asymmetry F has been measured using circularly polarized, tagged photons in the energy range 1200-2700 MeV, and the beam-target asymmetries H and P have been measured using linearly polarized, tagged photons in the energy range 1200-2000 MeV. These measurements significantly increase the database on polarization observables. The results are included in two partial-wave analyses and reveal significant contributions from several nucleon (N^{*}) resonances. In particular, contributions from new N^{*} resonances listed in the Review of Particle Properties are observed, which aid in reaching the goal of mapping out the nucleon resonance spectrum.

The aim of the study was to evaluate the association between the angiotensin-converting enzyme ACE I/D (rs 4340) polymorphism and DNA damage in patients with essential hypertension (EH). The I/D polymorphism of ACE was determined by polymerase chain reaction in 170 male hypertensive patients and 64 normotensive blood donors. We used flow cytometry to determine the levels of cell death, micronuclei and accumulation of peripheral blood leukocytes in G1/G0, S, G2/M phases of the cell cycle. Additionally, the whole blood samples were incubated in vitro at 4°C for 24 h to investigate the genotype effects on the susceptibility of cells to DNA damage. We found lower frequency of cells in DNA synthesis S phase and higher levels of micronuclei in the hypertensive compared to normotensive group (p 0.05) in the II genotype carriers too. However, hypertensive patients displayed different cellular response to incubation-induced DNA damages in the ACE I/D genotype groups; after incubation, the frequencies of micronuclei were significantly higher in the DD genotype carriers (p < 0.05). To conclude, the study suggests that the ACE I/D polymorphism may contribute to mechanisms and intensity of DNA damages in hypertensive and normotensive individuals.

Data on the reaction γ p → ω p with ω → π 0 γ , taken with unpolarized or polarized beams in combination with an unpolarized or polarized proton-target, were analyzed within the Bonn–Gatchina (BnGa) partial wave analysis. Differential cross sections, several spin density matrix elements, the beam asymmetry Σ, the normalized helicity difference E, and the correlation G between linear photon and longitudinal target polarization were included in a large data base on pion and photo-induced reactions. The data on ω photoproduction are used to determine twelve N ⁎ → N ω branching ratios; most of these are determined for the first time.

The polarization observables T , E , P , H , and G in photoproduction of η mesons off protons are measured for photon energies from threshold to W = 2400 MeV (T), 2280 MeV (E), 1620 MeV ( P , H ), or 1820 MeV (G), covering nearly the full solid angle. The data are compared to predictions from the SAID, MAID, JuBo, and BnGa partial-wave analyses. A refit within the BnGa approach including further data yields precise branching ratios for the Nη decay of nucleon resonances. A Nη-branching ratio of 0.33 ± 0.04 for N ( 1650 ) 1 / 2 − is found, which reduces the large and controversially discussed Nη-branching ratio difference of the two lowest mass J P = 1 / 2 − -resonances significantly.

Quasi-free photoproduction of $ \eta{^\prime}$ -mesons off nucleons bound in the deuteron has been measured with the combined Crystal Barrel - TAPS detector. The experiment was done at a tagged photon beam of the ELSA electron accelerator in Bonn for incident photon energies from the production threshold up to 2.5GeV. The $ \eta{^\prime}$ -mesons have been detected in coincidence with recoil protons and recoil neutrons. The quasi-free proton data are in good agreement with the results for free protons, indicating that nuclear effects have no significant impact. The coincidence with recoil neutrons provides the first data for the $ \gamma$ n $ \rightarrow$ n $ \eta{^\prime}$ reaction. In addition, also first estimates for coherent $ \eta{^\prime}$ -production off the deuteron have been obtained. In agreement with model predictions, the total cross-section for this channel is found to be very small, at most at the level of a few nb. The data are compared to model calculations taking into account contributions from nucleon resonances and t -channel exchanges

The photoproduction of ω mesons off the proton has been studied in the reaction γp→pω using the CEBAF Large Acceptance Spectrometer (CLAS) and the frozen-spin target in Hall B at the Thomas Jefferson National Accelerator Facility. For the first time, the target asymmetry T has been measured in photoproduction from the decay ω→π+π-π0, using a transversely polarized target with energies ranging from just above the reaction threshold up to 2.8 GeV. Significant nonzero values are observed for these asymmetries, reaching about 30-40% in the third-resonance region. New measurements for the photon-beam asymmetry Σ are also presented, which agree well with previous CLAS results and extend the world database up to 2.1 GeV. These data and additional ω photoproduction observables from CLAS were included in a partial-wave analysis within the Bonn-Gatchina framework. Significant contributions from s-channel resonance production were found in addition to t-channel exchange processes.

First results from the longitudinally polarized frozen-spin target (FROST) program are reported. The double-polarization observable E, for the reaction (p) over right arrow((gamma) over right arrow, pi(+))n, has been measured using a circularly polarized tagged-photon beam, with energies from 0.35 to 2.37 GeV. The final-state pions were detected with the CEBAF Large Acceptance Spectrometer in Hall B at the Thomas Jefferson National Accelerator Facility. These polarization data agree fairly well with previous partial-wave analyses at low photon energies. Over much of the covered energy range, however, significant deviations are observed, particularly in the high-energy region where high-L multipoles contribute. The data have been included in new multipole analyses resulting in updated nucleon resonance parameters. We report updated fits from the Bonn-Gatchina, Jfilich-Bonn, and SAID groups. (C) 2015 The Authors. Published by Elsevier B.V.

The first measurements of the beam-target-helicity-asymmetries $E$ and $G$ in the photoproduction of $\omega$-mesons off protons at the CBELSA/TAPS experiment are reported. $E$ ($G$) was measured using circularly (linearly) polarised photons and a longitudinally polarised target. $E$ was measured over the photon energy range from close to threshold ($E_\gamma = 1108$~MeV) to $E_\gamma = 2300$~MeV and $G$ at a single energy interval of $1108 < E_\gamma, Comment: 6 pages, 6 figures

The current status of ultrahigh energy diffractive collisions is presented. The Gribov total cross section universality is discussed in terms of the profile and -matrix functions in impact parameter space.

Data on the polarization observables T, P, and H for the reaction gamma p -> p pi(0) are reported. Compared to earlier data from other experiments, our data are more precise and extend the covered range in energy and angle substantially. The results were extracted from azimuthal asymmetries measured using a transversely polarized target and linearly polarized photons. The data were taken at the Bonn electron stretcher accelerator ELSA with the CBELSA/TAPS detector. Within the Bonn-Gatchina partial wave analysis, the new polarization data lead to a significant narrowing of the error band for the multipoles for neutral-pion photoproduction. (C) 2015 The Authors. Published by Elsevier B.V.

Photoproduction of two neutral pions off the proton is studied using linearly polarized photons, and the polarization observables I-s and I-c are measured for the first time. These two observables are unique to multi-meson final states; they characterize correlations between the linear photon polarization and the direction of outgoing single particles in photoproduction of three-body final states. The I-s and I-c distributions suggest that, in the 1.8 to 2.0 GeV mass region, the N(1520) 3/2(-)pi intermediate state is reached with reaction dynamics consistent with a dominant J(P) = 3/2(+) wave. These data are included in the Bonn-Gatchina (BnGa) partial wave analysis which is based on a large variety of data; the analysis confirms a significant contribution from the reaction chain gamma p -> N(1900)3/2(+) -> N(1520)3/2(-)pi(0) -> p pi(0)pi(0). (C) 2015 The Authors. Published by Elsevier B.V.

Hadronic resonance propagators which take into account the analytical properties of decay processes are built in terms of the dispersion relation technique. Such propagators can describe multi-component systems, for example, those when quark degrees of freedom create a resonance state, and decay products correct the corresponding pole by adding hadronic deuteron-like components. Meson and baryon states are considered, examples of particles with different spins are presented.

Vertex operators for photo- and electro-production of baryon states with arbitrary spin-parity, $ \gamma + N\to B(J^P)$, are constructed. The operators obey gauge invariance and analyticity constraints. Analyticity is realized as a requirement of the generalized Siegert theorem for vertex form factors., Comment: 10 pages

We consider as an example the two-pion decay of the ρ meson, the 3 S 1 q $$ \bar q $$ state of the constituent quarks—the decay being determined by the transition q $$ \bar q $$ → ππ contains information about confinement interactions. One can specify in this decay two types of transitions: (i) the bremsstrahlung radiation of a pion q → q + π (or $$ \bar q $$ → $$ \bar q $$ + π) with a subsequent fusion q $$ \bar q $$ → π, and (ii) the direct transition q $$ \bar q $$ → ππ. We demonstrate how in the amplitudes of the corresponding transitions the quark singularities have to disappear, i.e., what is the way the quark confinement at relatively short distances can be realized. We calculate and estimate the contributions of processes with bremsstrahlung radiation of the pion and of the direct transition q $$ \bar q $$ → ππ. The estimates demonstrate that the processes involving the direct transition q $$ \bar q $$ → ππ are necessary, but they cannot be determined unambiguously by the decay ρ(775) → ππ. We conclude that for the determination of the q $$ \bar q $$ → ππ transition more complete data on the resonance decays into the ππ channels are needed than those available at the moment.

In the framework of the relativistic and gauge invariant spectral integral technique, we calculate radiative decays rho(770)-> gamma pi(140) and omega(780)-> gamma pi(140) supposing all mesons (pi, rho and omega) to be quark-antiquark states. The q anti-q wave functions found for mesons and photon lead to a reasonably good description of data ($\Gamma^{(exp)}_{\rho^{\pm} \to\gamma\pi^{\pm}}=68\pm 30$ keV, $\Gamma^{(exp)}_{\rho^{0}\to\gamma\pi^0}=77\pm 28$ keV, $\Gamma^{(exp)}_{\omega\to\gamma\pi^0}=776\pm 45$ keV) that makes it possible to estimate the coupling for the bremsstrahlung emission of pion by quarks $g_\pi\equiv g_\pi (u\to d \pi)$. We have found two values for the pion bremsstrahlung coupling: $|g_\pi|=16.7 \pm 0.3 ^{+0.1}_{-2.3}$ (Solution I) and $|g_\pi|=3.0 \pm 0.3 ^{+0.1}_{-2.1}$ (Solution II). Within SU(6)-symmetry for nucleons, Solution I gives us for pi NN coupling the value $16.4 \le g_{\pi NN}^2/(4\pi) \le 23.2$ that is in qualitative agreement with the pi N scattering data, $g_{\pi NN}^2/(4\pi)\simeq 14$. For excited states, we have estimated the partial widths in Solution I as follows: $\Gamma (\rho_{2S}^\pm\to \gamma\pi)\simeq 10 - 130$ keV, $\Gamma (\rho_{2S}^0\to \gamma\pi)\simeq 10 -130$ keV, $\Gamma (\omega_{2S}\to \gamma\pi)\simeq 60 - 1080$ keV. The large uncertainties emphasise the necessity to carry out measurements of the meson radiative processes in the region of large masses.

The double-polarization observable E was studied for the reaction γp → pω using the CEBAF Large Acceptance Spectrometer (CLAS) in Hall B at the Thomas Jefferson National Accelerator Facility and the longitudinally polarized frozen-spin target (FROST). The observable was measured from the charged decay mode of the meson, ω → π+π−π0, using a circularly polarized tagged-photon beam with energies ranging from the ω threshold at 1.1 to 2.3 GeV. A partial-wave analysis within the Bonn-Gatchina framework found dominant contributions from the 3/2+ partial wave near threshold, which is identified with the subthreshold N(1720) 3/2+ nucleon resonance. To describe the entire data set, which consisted of ω differential cross sections and a large variety of polarization observables, further contributions from other nucleon resonances were found to be necessary. With respect to nonresonant mechanisms, π exchange in the t channel was found to remain small across the analyzed energy range, while Pomeron t-channel exchange gradually grew from the reaction threshold to dominate all other contributions above W ≈ 2 GeV.

The two reactions $\gamma p\to K^+\Lambda$ and $\pi^-p\to K^0\Lambda$ are analyzed to determine the leading photoproduction multipoles and the pion-induced partial wave amplitudes in slices of the invariant mass. The multipoles and the partial-wave amplitudes are simultaneously fitted in a multichannel Laurent+Pietarinen model (L+P model), which determines the poles in the complex energy plane on the second Riemann sheet close to the physical axes. The results from the L+P fit are compared with the results of an energy-dependent fit based on the Bonn-Gatchina (BnGa) approach. The study confirms the existence of several poles due to nucleon resonances in the region at about 1.9\,GeV with quantum numbers $J^P = 1/2^+$, $3/2^+, 1/2^-, 3/2^-, 5/2^-$., Comment: 18 pages, 12 figures

The helicity amplitudes for the photoproduction of nucleon resonances excited from neutrons are determined in the Bonn-Gatchina coupled-channel partial wave analysis. Upper limits for the decay fraction of the pentaquark candidate $N(1685)\ensuremath{\rightarrow}{K}^{0}\mathrm{\ensuremath{\Lambda}}$ are given. The electric and magnetic couplings at the pole positions are also tabulated, and these are used to suggest candidates for possible multiplets with quark-spin-1/2 and -3/2 content.

The reaction γp→K⁎+Λ was measured using the CLAS detector for photon energies between the threshold and 3.9 GeV at the Thomas Jefferson National Accelerator Facility. For the first time, spin-density matrix elements have been extracted for this reaction. Differential cross sections, spin density matrix elements, and the Λ recoil polarization are compared with theoretical predictions using the BnGa partial wave analysis. The main result is the evidence for significant contributions from N(1895)1/2− and N(2100)1/2+ to the reaction. Branching ratios for decays into K⁎Λ for these resonances and further resonances are reported.

A study of the partial-wave content of the γ p → η ′ p reaction in the fourth resonance region is presented, which has been prompted by new measurements of polarization observables for that process. Using the Bonn–Gatchina partial-wave formalism, the incorporation of new data indicates that the N ( 1895 ) 1 / 2 − , N ( 1900 ) 3 / 2 + , N ( 2100 ) 1 / 2 + , and N ( 2120 ) 3 / 2 − are the most significant contributors to the photoproduction process. New results for the branching ratios of the decays of these more prominent resonances to N η ′ final states are provided; such branches have not been indicated in the most recent edition of the Review of Particle Properties. Based on the analysis performed here, predictions for the helicity asymmetry E for the γ p → η ′ p reaction are presented.

The diquark–diquark–antiquark model describes pentaquark states both in terms of quarks and hadrons. The latest LHCb data for pentaquarks with open charm emphasize the importance of hadron components in the structure of pentaquarks. We discuss pentaquark states with hidden charm [Formula: see text] and those with open charm [Formula: see text] which were discovered recently in LHCb data ([Formula: see text] and [Formula: see text] spectra correspondingly). Considering the observed states as members of the lowest ([Formula: see text]-wave) multiplet, we discuss the mass splitting of states and the dumping of their widths.

Measurements of the linearly-polarized photon beam asymmetry Σ for photoproduction from the proton of η and η′ mesons are reported. A linearly-polarized tagged photon beam produced by coherent bremsstrahlung was incident on a cryogenic hydrogen target within the CEBAF Large Acceptance Spectrometer. Results are presented for the γp→ηp reaction for incident photon energies from 1.070 to 1.876 GeV, and from 1.516 to 1.836 GeV for the γp→η′p reaction. For γp→ηp, the data reported here considerably extend the range of measurements to higher energies, and are consistent with the few previously published measurements for this observable near threshold. For γp→η′p, the results obtained are consistent with the few previously published measurements for this observable near threshold, but also greatly expand the incident photon energy coverage for that reaction. Initial analysis of the data reported here with the Bonn–Gatchina model strengthens the evidence for four nucleon resonances – the N(1895)1/2−, N(1900)3/2+, N(2100)1/2+ and N(2120)3/2− resonances – which presently lack the “four-star” status in the current Particle Data Group compilation, providing examples of how these new measurements help refine models of the photoproduction process.

The helicity-dependent observable $E$ for the reaction $\ensuremath{\gamma}d\ensuremath{\rightarrow}\ensuremath{\eta}n(p)$ with a spectator proton was recently measured by the A2 Collaboration at MAMI in Mainz. The data were interpreted as further evidence for a narrow resonance with spin and parity ${J}^{P}=1/{2}^{+}$ $({P}_{11}$ wave). However, a full partial-wave analysis without any narrow resonance leads to an excellent description of the data. Imposing a narrow resonance with the properties suggested by the A2 Collaboration leads to a significant deterioration of the fit quality: there is no need for a narrow resonance.

Photoproduction of $\eta$ mesons from neutrons} \abstract{Results from measurements of the photoproduction of $\eta$ mesons from quasifree protons and neutrons are summarized. The experiments were performed with the CBELSA/TAPS detector at the electron accelerator ELSA in Bonn using the $\eta\to3\pi^{0}\to6\gamma$ decay. A liquid deuterium target was used for the measurement of total cross sections and angular distributions. The results confirm earlier measurements from Bonn and the MAMI facility in Mainz about the existence of a narrow structure in the excitation function of $\gamma n\rightarrow n\eta$. The current angular distributions show a forward-backward asymmetry, which was previously not seen, but was predicted by model calculations including an additional narrow $P_{11}$ state. Furthermore, data obtained with a longitudinally polarized, deuterated butanol target and a circularly polarized photon beam were analyzed to determine the double polarization observable $E$. Both data sets together were also used to extract the helicity dependent cross sections $\sigma_{1/2}$ and $\sigma_{3/2}$. The narrow structure in the excitation function of $\gamma n\rightarrow n\eta$ appears associated with the helicity-1/2 component of the reaction.

In terms of relativistic and gauge-invariant spectral-integral technique, we calculate amplitude for the π2 → γγ decay as a three-step transition π2 → q\( \bar q \)(2−+) → γ + q\( \bar q \)(1−−) → γγ. Using wave functions of the q\( \bar q \) components of photon (hep-ph/0406320) and those of pseudotensor mesons π2(1670), π2(2000), π2(2250), and π2(2510) (hep-ph/0511109), we obtain the following values for partial widths: Γπ2(1670)→γγ = 0.072 ± 0.007 keV, Γπ2(2000)→γγ = 0.037 ± 0.004 keV, Γπ2(2250)→γγ = 0.027 ± 0.003 keV, and Γπ2(2510)→γγ = 0.022 ± 0.002 keV. In the calculations, we use the momentum operator expansion, and, in this connection, discuss the problem of nilpotent operators inherent in the considered amplitude. It should be emphasized that measurement of two-photon decays of the π2 states can give valuable information about the long-range quark-antiquark forces which, as one may guess, are related to the quark confinement.

Objective: to analyze the effect of candesartan cilexetil and resveratrol of different dosages and combinations on the molecular and biological parameters of cell culture from bone marrow of mice and cytogenetic parameters of peripheral blood of the animals after physical activity. Material and methods. The cell culture from the bone marrow of C57Bl/6, Balb/C and ICR mice was used for the experiment. We analyzed the number of stem cells with CD117+ phenotype and the molecular and biological parameters (flow cytometry). The statistical processing of the data was performed using «Excel» and «Statistica», 6.0. Results. It was shown that the combined application of candesartan cilexetil and resveratrol increased the number of stem cells with CD117+ and had a stimulating effect on the proliferative processes in vitro and in vivo .

The reaction γ p → K S 0 Σ + is studied in the photon energy range from threshold. Linearly polarised photon beams from coherent bremsstrahlung enabled the first measurement of photon beam asymmetries in this reaction up to E γ = 1650 MeV . In addition, the recoil hyperon polarisation was determined through the asymmetry in the weak decay Σ + → p π 0 up to E γ = 2250 MeV . The data are compared to partial wave analyses, and the possible impact on the interpretation of a recently observed prominent structure in the cross section near the K ⁎ thresholds is discussed.

Partial-wave scattering amplitudes in baryon-baryon and baryon-antibaryon collisions and amplitudes for the production and decay of baryon resonances are constructed in the framework of the spin-momentum operator expansion method. The approach is relativistically invariant and it allows us to perform combined analyses of different reactions imposing analyticity and unitarity directly. The role of final-state interactions (triangle and box diagrams) is discussed.

Based on the data for the transitions pi0, eta, eta' -> gamma gamma^*(Q^2) and reactions of the e^+ e^- -annihilations, e^+ e^- -> rho0, omega, phi and e^+ e^--> hadrons at 1 q anti-q (q= u, d, s) for the region 0< Q^2, Comment: 17 pages, some typos corrected

We demonstrate the possibility of a good description of the processes $\phi (1020)\to \gamma\pi\pi$ and $\phi (1020)\to \gamma f_0(980)$ within the framework of non-relativistic quark model assuming $f_0(980)$ to be dominantly quark--antiquark system. Different mechanisms of the radiative decay, that is, the emission of photon by the constituent quark (additive quark model) and charge-exchange current, are considered. We also discuss the status of the threshold theorem applied to the studied reactions, namely, the behaviour of the decay amplitude at $M_{\pi\pi} \to m_\phi$ and $m_{f_0}\to m_\phi$. In conclusion the arguments favouring the $q\bar q$ origin of $f_0(980)$ are listed.

The Bethe-Salpeter equations for the light-quark composite systems, q q-bar, are written in terms of spectral integrals. For the q q-bar -mesons characterized by the mass M, spin J and radial quantum number n, the equations are presented for the following (n,M^2)-trajectories: pi_J, eta_J, a_J, f_J, rho_J, omega_J, h_J and b_J., Comment: 42 pages, 5 figures, typos corrected

Objectives: to analyze the cytogenetic parameters in vivo and in vitro in the administration of Resveratrol and Candesartan Cilexetil in different dosages and combinations. Material and methods. Male C57Bl/6 mice were used for the research. We investigated the molecular-biological parameters in vivo and in vitro and also the number of stem cells with CD117 phenotype (flow cytometry). The statistical analysis of the data was performed using Excel and Statistica. Results. Candesartan and Resveratrol in different dosages and combinations influence the molecular-biological parameters in vivo and in vitro . Candesartan at a dose of 3 mg/kg and its complex application with Resveratrol stimulate the formation of CD117 cells.

Results of a coupled channel isobar analysis of new high-statistics data on γ p → p η from MAMI are presented. A fit using known broad resonances and only standard background amplitudes cannot describe the relatively narrow peaking structure in the cross section in the mass region of 1660–1750 MeV which follows a minimum. An improved description of the data can be reached by either assuming the existence of a narrow resonance at a mass of about 1700 MeV with small photo-coupling or by a threshold effect. In the latter case the observed structure is explained by a strong (resonant or non-resonant) γ p → ω p coupling in the S 11 partial wave. When the beam asymmetry data, published by part of the GRAAL Collaboration, are included in the fit, the solution with a narrow P 11 state is slightly preferred. In that fit, mass and width of the hypothetical resonance are determined to M ∼ 1694 MeV and Γ ∼ 40 MeV , respectively, and the photo-coupling to Br η N A 1 / 2 p ∼ 2.6 ⋅ 10 − 3 GeV − 1 / 2 . High-precision measurements of the target asymmetry and F -observable are mandatory to establish the possible existence of such a narrow state and to provide the necessary information to define which partial wave is responsible for the structure observed in the data.

The quark structure of φ(1020) and f 0(980) is studied on the basis of data on the radiative decays φ(1020) → γπ 0, γη, γη′, γ a 0(980), γ f 0(980) and f 0(980) → γγ. The partial widths are calculated under the assumption that all the mesons under consideration are $$\bar qq$$ states: φ(1020) is a dominantly $$s\bar s$$ state ( $$\eta ' = n\bar nsin\theta + s\bar scos\theta $$ component contributes not more than 1%); η, η′, and π 0 are standard $$q\bar q$$ states, $$\eta = n\bar ncos\theta - s\bar ssin\theta $$ and $$\eta ' = n\bar nsin\theta + s\bar scos\theta $$ with θ≃37°; and f 0(980) is a e5 meson with the flavor wave function $$n\bar ncos\varphi + s\bar ssin\varphi $$ . The transition φ → γπ 0 specifies the admixture of the $$n\bar n$$ component in the φ meson: it is on the order of 0.5%. We argue that this order of $$n\bar n$$ value does not contradict data on the decay φ(1020) → γ a 0(980). The partial widths calculated for the decays φ → γη, γη‱ are in reasonable agreement with experimental data. The measured branching-ratio value Br(φ→γf 0(980))=(3.4±0.4 −0.5 +1.5 ×10−4) requires 25°≤|ϕ|≤90°. For the decay f 0(980) → γγ, the agreement with data, Γ(f 0(980) → γγ)=0.28 −0.13 +0.09 keV, is attained at either ϕ=85°±8° or ϕ=−46°±8°. A simultaneous analysis of the decays φ(1020) → γ f 0(980) and f 0(980) → γγ favors the solution with the negative mixing angle of ϕ=−48°±6°, setting f 0(980) very close to the flavor octet (ϕ octet=±54.7°).