Conformational and Functional Transitions in Class II α-mannosidase from <Emphasis Type="Italic">Aspergillus fischeri</Emphasis>

The conformational transitions in an oligomeric and high molecular weight class II α-mannosidase from Aspergillus fischeri were examined using fluorescence and CD spectroscopy under chemical, thermal and acid denaturing conditions. The enzyme lost the activity first and then the overall folded conformation and secondary structure. The midpoint values of GdnHCl mediated changes measured by inactivation; fluorescence and negative ellipticity were 0.48 M, 1.5 M and 1.9 M, respectively. The protein almost completely unfolded in 4.0 M GdnHCl but not at 90 °C. The inactivation and unfolding were irreversible. At pH 2.0, the protein exhibited molten-globule like intermediate with rearranged secondary and tertiary structures and exposed hydrophobic amino acids on the surface. This species showed increased accessibility of Trp to the quenchers and got denatured with GdnHCl in a different manner. The insoluble aggregates of a thermally denatured protein could be detected only in the presence of 0.25–0.75 M GdnHCl.     

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.     

Contribution of final-state interaction to the branching ratio of <Emphasis Type="Italic">B</Emphasis>→<Emphasis Type="Italic">J</Emphasis>/<Emphasis Type="Italic">ψ</Emphasis><Emphasis Type="Italic">D</Emphasis>

To test the validity of perturbative QCD (pQCD) and investigate its range of application, one should look for a suitable process. B→J/ψ D is a promising candidate. The linear momentum of the products is relatively small, so that there may exist a region where exchanged gluons are soft and the perturbative treatment may fail, so that the non-perturbative effect would be significant. We attribute such non-perturbative QCD effects to the long-distance final-state interaction (FSI) which is estimated in this work. We find that the contribution from the FSI to the branching ratio is indeed sizable and may span the rather wide range of 10⁻⁶∼10⁻⁵ and cover a region where the pQCD prediction is of the same order. A more accurate measurement of its branching ratio may provide important information about the application region of pQCD and help to clarify the picture of inelastic rescattering (i.e. FSI), which is generally believed to play an important role in B decays.     

The cusp effect in <Emphasis Type="Italic">η</Emphasis>′→<Emphasis Type="Italic">η</Emphasis><Emphasis Type="Italic">π</Emphasis><Emphasis Type="Italic">π</Emphasis> decays

Strong final-state interactions create a pronounced cusp in η′→η π ⁰ π ⁰ decays. We adapt and generalize the non-relativistic effective field theory framework developed for the extraction of π π scattering lengths from K→3π decays to this case. The cusp effect is predicted to have an effect of more than 8% on the decay spectrum below the π ⁺ π ⁻ threshold.     

<Emphasis Type="Italic">α</Emphasis>-cluster and <Emphasis Type="Italic">α</Emphasis>-binucleon states of 1<Emphasis Type="Italic">p</Emphasis>-shell nuclei

States that exhibit the properties of an α-cluster or an α-binucleon condensate are studied in 1p-shell nuclei. The generalized Hamiltonian of the Elliott SU(3) model is used to classify these states and to calculate their spectra. The results of the calculations are found to be in good agreement with experimental data. States not observed so far in the cluster spectra of the ¹²C, ¹⁶O, ¹⁰Be, and ¹²Be nuclei are predicted.     

The anisotropic cosmological models in <Emphasis Type="Italic">f</Emphasis>(<Emphasis Type="Italic">R</Emphasis>, <Emphasis Type="Italic">T</Emphasis>) gravity with <Emphasis Type="Italic">Λ(T)</Emphasis>

The rare decay \(B\rightarrow {K^{*}}\ell ^+\ell ^-\) is a very significant mode to search for physics beyond the Standard Model (SM). The mode provides a very rich spectrum of observables obtained from the angular distribution of its decay products. The recent LHCb measured values of these observables are used to conclude an evidence of right-handed currents at the kinematic endpoint of this decay mode. As the conclusion is drawn at the maximum dilepton invariant mass square (\(q^2\)) kinematic endpoint, it relies only on heavy quark symmetries where it is valid without significant corrections.     

Revised Spherically Symmetric Solutions of <Emphasis Type="Italic">R</Emphasis>+<Emphasis Type="Italic">ε</Emphasis>/<Emphasis Type="Italic">R</Emphasis> Gravity

We study spherically symmetric static empty space solutions in R+ε/R model of f(R) gravity. We show that the Schwarzschild metric is an exact solution of the resulted field equations and consequently there are general solutions which are perturbed Schwarzschild metric and viable for solar system. Our results for large scale contains a logarithmic term with a coefficient producing a repulsive gravity force which is in agreement with the positive acceleration of the universe.     

Inclusive <Emphasis Type="Italic">J</Emphasis>/<Emphasis Type="Italic">ψ</Emphasis> photoproduction and polarization at HERA in the <Emphasis Type="Italic">k</Emphasis><Subscript><Emphasis Type="Italic">T</Emphasis></Subscript>-factorization approach

We investigate the inclusive photoproduction of J/ψ mesons at HERA within the framework of the k _T -factorization QCD approach. Our study is based on the color singlet model supplemented with the relevant off-shell matrix elements and the CCFM and KMR unintegrated gluon densities in a proton and in a photon. Both the direct and resolved photon contributions are taken into account. Our predictions are compared with the recent experimental data taken by the H1 and ZEUS collaborations. Special attention is put on the J/ψ polarization parameters λ and ν, which are sensitive to the production dynamics.     

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.     

Study of in-medium <Emphasis Type="Italic">ω</Emphasis>-meson properties in <Emphasis Type="Italic">Ap</Emphasis> and <Emphasis Type="Italic">pA</Emphasis> collisions

The possibility to investigate the in-medium properties of the vector ω mesons at normal nuclear density is considered. The folding model and simulations with the RQMD generator have been used for studying of the ω-resonance production in Ap and pA reactions and its ω → π ⁰ γ → 3γ decay. We show that measurements in the inverse Ap kinematics is an effective way to get information about the ω-meson mass modification especially in not yet explored range of small meson momenta relative to the projectile nuclei where the strength of the effect is expected to be most strong. The traditional pA kinematics appears to be more preferable for the investigation of the in-medium ω-meson width. Using of compact electromagnetic calorimeter provides the possibility to collect large statistics and study the momentum dependencies of both the ω-meson mass and width at the density of normal nuclei.     

Exact solutions and conserved quantities in <Emphasis Type="Italic">f</Emphasis>(<Emphasis Type="Italic">R</Emphasis>, <Emphasis Type="Italic">T</Emphasis>) Gravity

This paper explores Noether and Noether gauge symmetries of anisotropic universe model in f(R, T) gravity. We consider two particular models of this gravity and evaluate their symmetry generators as well as associated conserved quantities. We also find exact solution by using cyclic variable and investigate its behavior via cosmological parameters. The behavior of cosmological parameters turns out to be consistent with recent observations which indicates accelerated expansion of the universe. Next we study Noether gauge symmetry and corresponding conserved quantities for both isotropic and anisotropic universe models. We conclude that symmetry generators and the associated conserved quantities appear in all cases.     

Transverse-momentum dependence of <Emphasis Type="Italic">J</Emphasis>/<Emphasis Type="Italic">ψ</Emphasis> shadowing effects

We present a new approach to estimate the effect of gluon shadowing in nucleus + nucleus collisions and its consequences on the J/ψ production yield. Using kinematical information available from the measured J/ψ production in proton + proton collisions at  GeV, we build a Glauber Monte Carlo code which takes into account shadowing in two alternative ways: multiple-scattering corrections or Q ² evolution of parton densities. We exploit the dependence of these different parameterizations to the J/ψ transverse momentum and we give the first predictions on the resulting p _T dependence of the nuclear modification factor in deuteron + gold collisions at the same energy.     

Study of the nuclear interaction of isoscalar <Emphasis Type="Italic">η</Emphasis>-, <Emphasis Type="Italic">ω</Emphasis>-, <Emphasis Type="Italic">ή</Emphasis>-, and <Emphasis Type="Italic">ϕ</Emphasis>-mesons

The possibility of experimental study of the nuclear interaction of mesons with nucleons and nuclei is considered.     

The quest for <Emphasis Type="Italic">μ</Emphasis> → <Emphasis Type="Italic">e</Emphasis><Emphasis Type="Italic">γ</Emphasis>: present and future

The quest for μ → eγ is one of the most important endeavors to search for New Physics beyond the Standard Model. In this talk I will review the current status of the experimental searches by the MEG Collaboration at PSI. I will also present a study of the experimental limiting factors that will define the ultimate performances, and hence the sensitivity, in the search for μ → eγ with continuous muon beams of extremely high rate (one or even two orders of magnitude larger than the present beams), whose construction is under consideration for the next decade.     

Polarization observables <Emphasis Type="Italic">P</Emphasis> + <Emphasis Type="Italic">A</Emphasis> and (<Emphasis Type="Italic">P</Emphasis> + <Emphasis Type="Italic">A</Emphasis>)σ in 200-MeV proton inelastic scattering

Experimental and calculated data on inelastic scattering of polarized protons are presented as polarization-analyzing-power combinations P + A and (P + A)σ for the 0⁺ → 1⁺, T = 1 transition in ¹²C. Data on the polarization P and the function (P ? A)σ are also reported. Microscopic calculations have been performed using the DWBA program with the G-matrix interaction based on the Paris and Bonn potentials. A significant difference between the effective interaction with density correction and free NN interaction has been demonstrated. It is established that the (P + A)σ combination is especially sensitive to systematic variations in the density dependence in effective NN interactions.