The 25Mg(p, γ)26Al and 25Mg(p,p′) resonances for Ep = 0.31–1.84 MeV

Thin target yield curves with good statistics have been measured for the ²⁵Mg(p, γ)²⁶Al and ²⁵Mg(p, p′)²⁵Mg reactions in the E_p = 310–1845 keV region. Altogether 76 resonances have been observed, of which 45 only in (p, γ), 30 in both (p, γ) and (p, p′), and one only in (p, p′). Several of these resonances had not been observed previously in either of the two reactions, and several of the previously observed resonances turned out to be doublets. All 39 ²⁵Mg(p, p₀)²⁵Mg resonances found previously in the E_p = 700–1845 keV region resonate in (p, γ) and many also in (p, p′). Resonance strengths have been derived relative to that of the E_p = 593 keV resonance.The analysis of weak (p, p₁) and (p, p₂) resonance yields has been supported by a calculation of the yields in the continuum (in between resonances) due to the Breit-Wigner tails of strong and broad resonances in the neighbourhood (with interference between resonances with the same J^π; T taken into account), and to Coulomb excitation.     

Graded orthosymplectic geometry and OSp (4;1)-invariant fermionic σ models

A geometry based on the fundamental 4+N-dimensional linear representation of the extended super-de Sitter group OSp(4;N) is considered. For N=1 two OSp(4;1)-invariant fermionic models are discussed.On leave of absence from Institute of Theoretical Physics, University of Wrocaw, Wrocaw, Poland.     

Invariant Mass Spectroscopy of 23O via the (p, p′) Reaction in Inverse Kinematics

The neutron-rich oxygen isotope ²³O has been investigated via proton inelastic scattering on a liquid hydrogen target at 63.5 MeV/nucleon. The invariant mass method in inverse kinematics was employed to reconstruct the energy spectrum. A sharp resonance state was observed at 42(5) keV above the neutron threshold. A comparison of the differential cross section leading to this state with a microscopic DWBA calculation allowed a J ^π assignment of 5/2⁺ for this state.     

The nuclear structure of 126Te studied with (d,p), (d,3He) and (d,d′) reactions

At the Munich Tandem Accelerator the reactions ¹²⁵Te(d, p)¹²⁶Te, ¹²⁶Te(d, d′)¹²⁶Te and ¹²⁷I(d, ³He)¹²⁶Te were measured with deuteron energies between 24 and 28 MeV up to excitation energies of about 3.2 MeV. Using γ-lines from previous (n,γ), (n,n′γ) and (γ,γ′) experiments, a level scheme of ¹²⁶Te up to above 3 MeV was established. The results are compared with quasiparticle-phonon model calculations.     

Relativistic equations and indecomposable representations of the Lorentz groupSL(2, ℂ)

Relativistic equations in which the fields cotransform under the direct sum of ordinary indecomposable representations of the Lorentz group are derived and discussed.Talk given at the Symposium on Mathematical Methods in the Theory of Elementary Particles, Liblice castle, Czechoslovakia, June 18–23, 1978.     

On the relation between Φ(1,2) and Φ(1,5) perturbed minimal models and unitarity

We consider the RSOS S-matrices of the Φ_(1,5) perturbed minimal models which have recently been found in a companion paper. These S-matrices have some interesting properties, in particular, unitarity may be broken in a stronger sense than seen before, while one of the three classes of Φ_(1,5) perturbations (to be described) shares the same thermodynamic Bethe ansatz as a related Φ_(1,2) perturbation. We test these new S-matrices by the standard Truncated Conformal Space method, and further observe that in some cases the BA equations for two particle energy levels may be continued to complex rapidity to describe (a) single particle excitations and (b) complex eigenvalues of the Hamiltonian corresponding to non-unitary S-matrix elements. We make some comments on identities between characters in the two related models following from the fact that the two perturbed theories share the same breather sector.     

Quantum-mechanical and continual models of magnetic dynamics for antiferromagnetic particles in Mössbauer spectra analysis

A standard multi-level relaxation model of magnetic dynamics of single-domain particles together with recently developed quantum-mechanical and continual models of specific thermo- and magnetic dynamics of antiferromagnetic particles were applied to analyse temperature series of Mössbauer spectra of Fe₂O₃ based nanoparticles. Advantages of these models, their comparison and further generalizations are discussed on the example of the particular experimental data.     

Transverse (e,e′) Response Functions for 4He

This poster presentation is intended to show preliminary results from calculations of the inclusive (e,e′) transverse response functions of ⁴He. Up to now we have only included the E1 and M1 multipoles and therefore no comparison with experiment is shown. That will be done once all relevant multipoles have been calculated. Details of the calculation are summarized in the text below.     

Stability of proton and maximally symmetric minimal unification model for basic forces and building blocks of matter

With the hypothesis that all independent degrees of freedom of basic building blocks should be treated equally on the same footing and correlated by a possible maximal symmetry, we arrive at a 4-dimensional space-time unification model. In this model the basic building blocks are Majorana fermions in the spinor repre- sentation of 14-dimensional quantum space-time with a gauge symmetry GM4D = SO(1,3)×SU(32)×U(1)A×SU(3)F. The model leads to new physics including mirror particles of the standard model. It enables us to issue some fundamental questions that include: why our living space-time is 4-dimensional, why parity is not con- served in our world, how the stability of proton is, what the origin of CP violation is and what the dark matter can be.     

Search for an enhanced production of low energy pions in C(p, π+)X,Cu(p, π+)X,and Cu(p, π∘)X reactions for 300 MeV≦Tp≦400 MeV

The observation of an enhancement in the production of low energy pions in the Cu(p, ⁺)X reaction is confirmed. The width of the bump is about 5 MeV around 350 MeV. A similar enhancement appears at 330 MeV for C(p, ⁺)X but the width has not been measured. An attempt to observe this behaviour in Cu(p, )X is described. From the data one cannot conclude about the existence of a structure around 350 MeV proton energy. The lack of resolution in the spectrometer may have washed out the small effect expected from ⁺ measurements.     

Density functional investigations for geometric and electronic properties of In4M and In12M （M = C,Si, In） clusters

First-principle calculations are performed to study geometric and electronic properties of both neutral and anionic In4M and In12M （M = C, Si, In） clusters. In4C and In4Si are found to be tetrahedral molecules. The icosahedral structure is found to be unfavourable for In12M. The most stable structure for In12C is a distorted buckled biplanar structure while for In12Si it is of an In-cage with the Si located in the centre. Charge effect on the structure of In12M is discussed. In4C has a significantly large binding energy and an energy gap between the highest-occupied molecularorbital level and the lowest unoccupied molecular-orbital level, a low electron affinity, and a high ionization potential, which are the characters of a magic cluster, enriching the family of doped-group-IIIA metal clusters for cluster-assembled materials.