Description of high-spin isomers in theN=82 region

The high spin states and of those especially the yrast isomers are studied in the region near the rare earth nuclei. The deformation energy surface is calculated with a method modelled in principle according to a shape constrained cranked HF theory (CHF). In practice, the expectation value of the many-body Hamiltonian is calculated with cranked Nilsson functions. One finds rotation around a slightly deformed oblate or prolate symmetry axis in front or behind the rare earth region, respectively. Near the Hf isotopes strongly prolate deformed nuclei rotating around the symmetry axis are found in agreement with the knownK isomers in this region. These results are explained also qualitatively with the help of the MONA (Maximisation of theOverlap ofNucleonic wave functions byAlignment of single particle angular momenta) effect. In the second part high spin states and yrast isomers in theN=82 region are calculated in the cranked Hartree-Fock-Bogoliubov approach with four and six quasi-particle excitations. For the excitation energies in¹⁴⁶Gd and¹⁵²Dy and a measuredg factor one finds satisfactory agreement.     

The MTV experiment: a test of time reversal symmetry using polarized 8Li

The MTV (Mott Polarimetry for T-Violation Experiment) experiment at TRIUMF-ISAC (Isotope Separator and ACcelerator), which aims to achieve the highest precision test of time reversal symmetry in polarized nuclear beta decay by measuring a triple correlation (R-correlation), is motivated by the search for a new physics beyond the Standard Model. In this experiment, the existence of non-zero transverse electron polarization is examined utilizing the analyzing power of Mott scattering from a thin metal foil. Backward scattering electron tracks are measured using a multi-wire drift chamber for the first time. The MTV experiment was commissioned at ISAC in 2009 using an 80 % polarized ⁸Li beam at 10⁷ pps, resulting in 0.1 % statistical precision on the R-parameter in the first physics run performed in 2010. Next generation cylindrical drift chamber (CDC) is now being installed for the future run.     

A reexamination ofSU(6) symmetry breaking in high-energy phenomenology

A permutationally-symmetric form for the nucleon wave function consisting of a linear combination of the56 ground state and the70 excited state is used to reexamine the nucleon structure functions and form factors. This form of wave function reproduces the results of the successful Carlitz-Kaur model, differing only in the addition of a term that is proportional to the square of the mixing coefficient between the56 and the70 states. Values of this mixing coefficient are obtained from the structure functions and from the initial slope of the neutron electric form factor using relativistic wave functions constructed by Henriques, Kellett, and Moorhouse. The signs of these values are in agreement, so that the model avoids the contradiction noted by Le Yaouanc et al. This result is due to the dependence of the neutron electric form factor calculation on the spin wave function and associated matrix elements.     

On scalar resonances in ππ→ππ,K\bar K, ηη reactions

Carried out is the analysis of the new experimental data on theS-wave of the ππ→ \(K\bar K\) reaction in common with ππ→ππ one in the 1–1.6 Gev energy region. It is shown that new resonances are not required for the explanation of the data and for that the well-knownS ^* (980) and ε (1300–1400) resonances and their mixing only are enough. Once more confirmed is the possibility forS ^* (980) to be the \(qq\bar q\bar q\) from (9,0⁺) nonet of the \(qq\bar q\bar q\) mesons predicted by the MIT-bag model. Moreover, it is shown that the ε(1300–1400) resonance can be interpreted as a member of the second four-quark (9,0⁺)-nonet. We predict the bright manifestation of theS ^* and ε-resonances in the π⁺π^? →ηη reaction. The analysis of the data shows that the ε-meson cannot be a pureSU (3)-singlet and therefore it cannot pretend to the role of the gluonium. Discussed is critically the Törnqvist's analysis for scalar mesons.     

Hyperfine interaction of Ce and La in 3-d ferromagnets

NMR/ON measurements on¹⁴¹CeFe show the sign of the hyperfine field of CeFe to be negative. For the¹⁴¹Ce nucleus a g-factor of ¦g_N¦=0.311±0.011 is found. With this g-value a hyperfine field of H_hf=?41±2 T for CeFe is derived. Low temperature nuclear orientation experiments on¹⁴¹CeCo and¹⁴⁰LaFe yield ¦H_hf¦=30±3 T and ¦H_hf¦=46±5 T respectively. The valence of cerium impurities in Fe, Co and Ni is discussed.     

Frequency dependence of the freezing temperature in spin glasses: A comparative study of (La,Gd)B6, (Y,Gd)Al2 and (La,Gd)Al2

The frequency dependence of the freezing temperatureT _f(ν) is determined for the dilute spin glass systems (La, Gd)B₆ and (Y, Gd)Al₂ in the frequency range 10–1,000 Hz. While for (La, Gd)B₆,T _f(ν) is found to be weak, for (Y, Gd)Al₂ T _f(ν) is even stronger than for the previously studied system (La, Gd)Al₂. Both, measurements of the temperature dependence of the susceptibility nearT _f and calculations of the RKKY pair interaction, suggest that this difference is correlated with a different sign of the nearest-neighbor interaction, which appears to be antiferromagnetic for (La, Gd)B₆ and ferromagnetic for (Y, Gd)Al₂ as well as (La, Gd)Al₂.     

Hyperfine fields in the 5sp series studied by the low temperature nuclear orientation of83Rb,83Sr,85Sr and85Ym in iron

The hyperfine fields B_hf (RbFe), B_hf (SrFe) and B_hf (YFe) have been determined by the low temperature nuclear orientation of dilute samples of⁸³Rb,^83,85Sr and⁸⁵Y^m in an iron lattice to be B_hf (RbFe)=+54 (10) kG, B_hf (SrFe)=(?)100 (30) kG and B_hf (YFe)=?226 (10) kG. These results are compared with recent calculations for these fields (1), (2).     

Study on 222–226Th Isotopes in the Cranking Framework

The yrast spectra, quadrupole moments, quadrupole deformation parameters (β ₂), non-axiality parameters (γ), root mean-square radii for protons and neutrons, occupation probabilities, moment of inertia (I), and B(E2) transition probabilities are calculated for ^222–226Th in the cranked Hartree–Bogoliubov framework. The calculations employ a quadrupole-quadrupole plus pairing model of residual interaction operating in a reasonably large valence space outside the ¹⁶⁴Pb core. Our calculations reproduce qualitatively the observed yrast spectra in ^222–226Th up to spin 20⁺. The calculated results indicate that the non-axiality parameter decreases as one moves along the yrast states. The observed increase in deformation from ²²²Th to ²²⁶Th is due to the increase in the occupation of low-k components of $(2g_{9/2})_{\pi }$ and $(1j_{{15/2}})_{\nu }$ orbits. The model parameters reproduce not only the moment of inertia, deformation, and transition probabilities but also the proton and neutron pairing gaps and are the most appropriate for cranking studies in this region.     

A fast, low perturbation ionization beam profile monitor based on a gas-jet curtain for the ultra low energy storage ring

An ionization beam profile monitor relying on a supersonic gas-jet shaped into an extended, thin curtain is proposed for operation in an ultra high vacuum environment for very low perturbation on the accelerated beam, as requested for the in-ring profile monitoring at the Ultra low energy Storage Ring (USR) at the Facility for Low-energy Antiproton and Ion Research (FLAIR), in Darmstadt. In this paper, we describe the working principle of the monitor, as well as providing an analysis of sensitivity and resolution dependence on geometrical design and gas curtain thickness.     

Measurement of theg-factor of the 21 + state of192Pt in an external magnetic field

Theg-factor of the 2₁ ⁺ state of¹⁹²Pt has been measured by the IPAC technique in an external magnetic field as:g(2₁ ⁺,¹⁹²Pt)=+0.287(17). An additional IPAC experiment with an¹⁹²IrFe sample was performed with the same level in order to investigate the hyperfine field. The result:ω _L τ(2₁ ⁺,¹⁹²PtFe)=0.1115(9) gives the hyperfine field:B _hf ^4.2k (PtFe)=126.8(71) T. The result of an LTNO experiment with the same level is compatible with the assumption that 100% of the¹⁹²Ir atoms were on unique sites.     

SU(5) andSU(2)×U(1) radiative breakings inN=1 supergravity unified models

Non-minimalSU(5) supergravity GUTs are analyzed in order to obtain theSU(5) andSU(2)×U(1) breakings à la Coleman-Weinberg as dynamical effects generated by the soft breaking terms, residues of supergravityN=1 (minimally coupled). Solutions are found that predict the existence ofSU(2)-triplets andSU(3)-octets as heavy asO(1 TeV). Supersymmetric Higgs masses, of the same order than the gravitino mass, must be introduced for the heavy, Σ(24), and lightH ₁ (2),H ₂ (2) sectors. Imposing the experimental bound \(m_{\tilde g} \gtrsim 60GeV\) , the lower boundsm _3/2?30 GeV, \(m_{\bar e} > 140GeV\) \(m_{\bar u} > 133GeV\) are obtained.     

Nuclear orientation and resonance studies of96TcFe

Low temperature nuclear orientation and nuclear magnetic resonance (NMRON) have been used to measure the magnetic hyperfine interaction in⁹⁶TcFe and the decay scheme properties of⁹⁶Tc. The spin of the⁹⁶Tc ground state is confirmed as 7. Its magnetic moment μ(⁹⁶Tc)=5.37±0.17 n.m. The magnetic hyperfine field for⁹⁶TcFe is ?298±10 kOe. The anisotropies of the 778, 813, 850 and 1126 keV transitions in⁹⁶Mo agree with pure E2 multipolarity assignments. The spin-parity of the 2876 keV level is 7⁺.     

ASO (10) model with Majorana masses for the vr's around 1011 GeV

A unified gauge model is built with Higgs in 210⊙126⊙10 representations and intermediate symmetry $$SU(3)_c \otimes SU(2)_L \otimes SU(2)_R \otimes U(1)_{B - L} .$$ . The vacuum of the210 is in a two-dimensional stratum. From the values sin²θ _W (M _W ) and \(\frac{\alpha }{{\alpha _s }}(M_W )\) one determines the high scales, with the result to predict leptoquarks heavier than 10¹⁵ GeV and Majorana masses for the right-handed neutrinos around 10¹¹ GeV.     

Preliminary design studies of an extraction of the USR

The next-generation Facility for Low energy Antiproton and Ion Research (FLAIR) at GSI is going to be a dedicated research facility for ion research in the keV range. These ion beams will allow to explore fundamental properties in matter-antimatter research at ultra-low energies of only 20 keV/q in hitherto impossible experiments. To provide these very low energy beams, the Ultra-low energy Storage Ring (USR), an electrostatic synchrotron, will play a major role within the FLAIR complex. It combines the electrostatic storage mode with deceleration from an initial energy of 300 keV/q down to 20 keV/q—as well as an efficient beam cooling. To fulfill its role as a multi-purpose experimental facility, the design of the USR has not only to cover in-ring experiments, but needs to include a highly flexible beam extraction for serving different external experiments as well.     

Superdeformation in194Pb

High spin states in the odd- odd nucleus¹²⁴Cs have been investigated within theNordball collaboration. In the yrast cascade which is determined as a πh_11/2 ? νh_11/2 configuration, a rather large signature splitting in the ratios, B(M1)/B(E2), has been observed. Furthermore, signature inversion is suggested in the lower spin part of the yrast band.     

A remark concerning 20 plet dominance in charm decays

Based onV spin consideration, it is argued that20 dominance in the effective weak Lagrangian does not strongly reduce theinclusive decay rate ofD ⁺ mesons. Decays of the typeD→Kρ,K ^*π, ρπ are discussed in pointing out that 20 dominance should lead to a large enhancement of \(D^ + \to \bar K^0 \rho ^ + ,\left( {\bar K^0 } \right) * \pi ^ + \) over \(D^ + \to \bar K^0 \pi ^ + \) ;W exchange, on the other hand, leads to a sizeable suppression ofD ⁰→K ^? ρ ⁺,(K ^?)*π⁺ relative toD ⁰→K ^?π⁺.     

Vacancy trapping by 5sp series impurities in rolled and implanted nickel foils

Nickel foils containing substitutional¹¹⁹Sb,¹²¹Sb and¹²⁵Sb impurities were deformed by rolling at room temperature and subsequently subjected to an isochronal annealing treatment. After each annealing step, a Mössbauer spectrum was measured. In the annealing temperature range from 350 to 800 K, in addition to the component for substitutional impurities, components ascribed to impurity atoms associated with one or more vacancies were observed in all cases. After annealing at 850 K and higher, only the substitutional component remains. Though very similar in general, some of the spectra for deformed¹¹⁹SbNi samples show clear differences from those obtained for implanted¹¹⁹SnNi samples. Additional experiments were performed on implanted sources of¹²¹Te and¹²⁹Te in nickel. Here, substantial vacancy trapping is already present in undeformed and unannealed foils. Rolling of the¹²⁹TeNi sources leads to a considerable increase of trapping after subsequent annealing at intermediate temperatures. For the insoluble Te impurities, a purely substitutional solution can not be recovered by annealing at higher temperatures. The evolution of vacancy trapping at the impurities that serve as probes and the dependence of the hyperfine field and the isomer shift of the impurities on the trapped vacancy configurations are discussed.     

Ion implantation a powerful technique for the production of metastable superconducting alloys

Ion implantation at liquid helium temperatures is a new method of producing metastable alloys. The special features of this alloying technique are illustrated by two selected examples of dilute and concentrated alloys, respectively. Superconductors containing small amounts of paramagnetic (3d)-impurities such asHgMn, PbMn andSnMn exhibit strong pair breaking effects. In the case ofSnMn the Kondo effect is observed. Concentrated alloys of Pd and Pd-noble metal alloys with hydrogen (deuterium) are only superconducting in a very high concentration range, being unstable at room temperature. Such concentrations can be achieved by ion implantation at liquid He-temperatures. The superconducting transition temperature can thus be raised to a maximum value of 16.6 K in aH/Pd _0.55 Cu_0.45?0.7 alloy.     

Demonstration of the origins of cooperativity within SU2×L 6 mapping over\left\{ {I\tilde H_\upsilon } \right\} Liouvillian carrier subspaces characterising the MQ-NMR cluster [A]6(L 6) and its\{ |kq\upsilon :[\tilde \lambda ] > > \} tensorial bases

The fundamental mappings over carrier subspace and substructures associated with \(\{ |kq\upsilon > > \} \) augmented spin algebras of Liouville space, and their mapping onto a subduced symmetry, are derived for [A]₆(L ₆) spin clusters within the combinatorial context of Rota-Cayley algebra over a field. Use of suitable lexical sets of combinatorialp-tuples (number partitions) over {|IM(M ₁?M _n )>}M, followed by the subsequent use ofL _n inner tensor product (ITP) algebra, allows the substructure of Liouville space to be derived. For SU2×L ₆ mapping over the simply-reducible \(\left\{ {I\tilde H_\upsilon } \right\}\) carrier subspaces, the \(D^k \left( {\tilde U} \right) \times \tilde \Gamma ^{\left[ {\tilde \lambda } \right]} \left( \upsilon \right)\) (L ₆) dual irreps, also arise as a consequence of the Liouville space recoupling termsv≡{k ₁?k _n } being distinct labels for \(\left\{ {I\tilde H_\upsilon } \right\}\) which are themselves amenible to combinatorial analysis within the concept of Rota-Cayley algebra. Hence, theL _n -induced symmetry aspects of multiquantum NMR density matrix formalisms and their dual \(\{ |kq\upsilon :[\tilde \lambda ] > > \} \) tensorial bases of spin cluster problems are derived and the nature of the cooperative, aspect between the individual symmetries comprising the duality is demonstrated, i.e. in the context of the operator bases of Liouville space. These practical arguments correlate, well with those based on an augmented boson pattern algebra derived from a Heisenburg algebra for superoperators, ?_±,?₀. An earlier, treatment of conventional Hilbert space SU2×L ₆ dualitycould only be realised in terms of standard SU2 boson algebra. Since the recoupling Rota-‘field’v for Liouville space is an explicit aspect of the dual mapping, a direct demonstration of cooperativity exists.