Direct mass measurements of neutron-deficient 152Sm projectile fragments at the FRS-ESR facility

The FRS-ESR facility at GSI provides one of the most efficient methods for direct mass measurements. In the present experiment, exotic nuclei were produced via fragmentation of ¹⁵²Sm projectiles in a thick beryllium target at 500-600 MeV/u, separated in-flight with the fragment separator FRS, and injected into the storage-cooler ring ESR. Time-resolved Schottky Mass Spectrometry was applied for mass measurements of stored and electron-cooled bare and few-electron ions. 373 different nuclides were identified by means of the spectra of their revolution frequencies. Masses for 18 nuclides (⁸⁴Zr, ⁹²Ru, ⁹⁴Rh, ^107,108,110Sb, ^111,112,114I, ¹¹⁸Ba, ^122,123La, ¹²⁴Ce, ¹²⁷Pr, ¹²⁹Nd, ¹³²Pm, ¹³⁴Sm, ¹³⁷Eu) have been determined for the first time. Masses for ^111,112I and ¹¹³Xe have been obtained via known α-decay energies. The experiment and first results will be presented.     

Discriminant Analysis of Volatile Organic Compounds data related to a new location method of entrapped people in collapsed buildings of an earthquake

Discriminant Analysis is used as a part of a research, which aims at using expired air analysis for the early location of entrapped people under the ruins of collapsed buildings in an earthquake. This work focuses on the possibility of distinguishing Volatile Organic Compounds (VOCs) in the entrapment area which originate from different sources. Five categories of samples were analyzed by Thermal Desorption-Gas Chromatography-Mass Spectrometry (TD-GC-MS). Expired air samples from healthy humans (Category 1) and fasting people (Category 2) were analyzed for studying the VOCs attributed to entrapped people. Headspace air of urban waste disposal bins (Category 3), headspace air of bags with decaying human bodies (Category 4) and urban air samples (Category 5) were analyzed for studying the VOCs attributed to background sources. Discriminant Rotation, a specific type of Discriminant Analysis was applied on the VOCs concentration matrix of the five categories. Combinations of VOCs that best discriminated each category were determined. Cluster Analysis was used to validate the results of Discriminant Analysis. The advantages and limitations of the method are presented and discussed.     

Loop Groups and Twin Buildings

In these notes we describe some buildings related to complex Kac–Moody groups. First we describe the spherical building of SL_n() (i.e. the projective geometry PG(ⁿ)) and its Veronese representation. Next we recall the construction of the affine building associated to a discrete valuation on the rational function field (z). Then we describe the same building in terms of complex Laurent polynomials, and introduce the Veronese representation, which is an equivariant embedding of the building into an affine Kac–Moody algebra. Next, we introduce topological twin buildings. These buildings can be used for a proof which is a variant of the proof by Quillen and Mitchell, of Bott periodicity which uses only topological geometry. At the end we indicate very briefly that the whole process works also for affine real almost split Kac–Moody groups.Supported by a Heisenberg fellowship by the Deutsche Forschungsgemeinschaft.     

On kaonic hydrogen. Phenomenological quantum field theoretic model revisited

We argue that due to isospin and U-spin invariance of strong low-energy interactions the S-wave scattering lengths a ⁰ ₀ and a ¹ ₀ of ˉN scattering with isospin I = 0 and I = 1 satisfy the low-energy theorem a ⁰ ₀ +3a ¹ ₀ = 0 valid to leading order in chiral expansion. In the model of strong low-energy ˉN interactions at threshold (Eur. Phys. J. A 21, 11 (2004)) we revisit the contribution of the Σ(1750) resonance, which does not saturate the low-energy theorem a ⁰ ₀ +3a ¹ ₀ = 0, and replace it by the baryon background with properties of an SU(3) octet. We calculate the S-wave scattering amplitudes of K^-N and K^-d scattering at threshold. We calculate the energy level displacements of the ground states of kaonic hydrogen and deuterium. The result obtained for kaonic hydrogen agrees well with recent experimental data by the DEAR Collaboration. We analyse the cross-sections for elastic and inelastic K^-p scattering for laboratory momenta 70MeV/c < p _K < 150MeV/c of the incident K^--meson. The theoretical results agree with the available experimental data within two standard deviations.     

Partition Complexes, Tits Buildings and Symmetric Products

We construct a homological approximation to the partition complex,and identify it as the Tits building. This gives a homologicalrelationship between the symmetric group and the affine group,leads to a geometric tie between symmetric powers of spheresand the Steinberg idempotent, and allows us to use the self-dualityof the Steinberg module to study layers in the Goodwillie towerof the identity functor. 2000 Mathematics Subject Classification:55N25, 55S15, 20B30, 55P25.     

(2 + 1)D exotic Newton-Hooke symmetry, duality and projective phase

A particle system with a (2 + 1)D exotic Newton-Hooke symmetry is constructed by the method of nonlinear realization. It has three essentially different phases depending on the values of the two central charges. The subcritical and supercritical phases (describing 2D isotropic ordinary and exotic oscillators) are separated by the critical phase (one-mode oscillator), and are related by a duality transformation. In the flat limit, the system transforms into a free Galilean exotic particle on the noncommutative plane. The wave equations carrying projective representations of the exotic Newton-Hooke symmetry are constructed.     

The adiabatic approximation to exotic leptonic molecules: further analysis and a nonlinear equation for conditional amplitudes

Recent successful applications of a particular kind of adiabatic approximation to complexes of muons and positrons with atoms, motivated us to perform a new analysis of the molecular approximations on this perspective. We focus our attention mainly on the various levels of the adiabatic approximation and discuss if and how it can be stressed to yield exact results. In the course of this analysis a new nonlinear equation for conditional amplitudes was obtained.     

Convex rank 1 subsets of Euclidean buildings (of type A 2)

For a Euclidean building X of type A ₂, we classify the 0-dimensional subbuildings A of ∂ _T X that occur as the asymptotic boundary of closed convex subsets. In particular, we show that triviality of the holonomy of a triple (of points of A) is (essentially) sufficient. To prove this, we construct new convex subsets as the union of convex sets.      

地方建筑的保护与开发

地方建筑作为一种文化遗产,具有较高的精神和经济价值以及深远的历史意义.当前,由于人们忽视地方建筑的价值,造成地方建筑资源的衰败.对如何正确保护地方建筑这一个重要课题进行了系统的总结和论述.     

X-ray transitions from antiprotonic noble gases

The onset of antiprotonic X-ray transitions at high principal quantum numbers and the occurrence of electronic X-rays in antiprotonic argon, krypton, and xenon has been analyzed with the help of Multiconfiguration Dirac-Fock calculations. The shell-by-shell ionisation by Auger electron emission, characterised by appearance and disappearance of X-ray lines, is followed through the antiprotonic cascade by considering transition and binding energies of both the antiproton and the remaining electrons. Electronic lines could be attributed partly to specific states of the antiprotonic atom de-excitation.