On the nature ofC(1480) resonance

The dynamic interpretation of theC(1480) resonance in the φπ⁰ mass spectrum is discussed in detail. It is shown thatC(1480) can result from a rare decay ρ′(1600)→φπ⁰ originating from OZI rule violation due to coherently amplified intermediate processes ρ′(1600)→ \(K*\bar K + \bar K*K\) →φπ⁰ in the region of logarithmic singularity. Some checks of this interpretation ofC(1480) are given. It is shown that one cannot describe the φπ⁰ data by a nonresonant amplitude π⁰ p→( \(K*\bar K + \bar K*K\) )n→φπ⁰ n with Regge parametrizedK andK ^* exchanges in the block π^?π⁺→ \(K*\bar K + \bar K*K\) →φπ⁰. The decays ρ′(1600)→ωπ⁰, \(K*\bar K + \bar K*K\) ? η are also discussed.     

Spin dependence of the parity non-conserving neutron-nucleus interaction

We show that the spin dependence of the parity violating amplitudes can provide a clue to the precise origin of the large parity non-conserving effects observed in neutron scattering on nuclei. The polarization asymmetries for longitudinal and transverse polarization of the incoming neutrons allow the separation of these spin amplitudes. In the mechanism of parity admixing of the virtually excited compound nucleus states, the spin dependence of the weak amplitudes is determined by the spin dependence of the strong interaction amplitudes for the elastic channel of the decay of the p-wave resonance     

Multiquark picture for Σ (1620)

In this work we report on a new QCD sum rule analysis to predict masses of the excited baryon states (e.g. Σ (1620) and Λ (1405)) by using multiquark interpolating fields ((qˉq)(qqq)). For the Σ (1620) we consider the ˉKN, πΣ, and πΛ (I = 1) multiquark interpolating fields. The calculated mass from those multiquark states is about 1.592 GeV. For the Λ (1405) we first show the result using the π⁺Σ⁻+π⁰Σ⁰+π⁻Σ⁺ (I = 0) multiquark interpolating field, and compare the calculated mass to that of our previous result using the π⁰Σ⁰ multiquark state. We then show that the mass 1.405 GeV is well reproduced when using the ˉKN (I = 0) multiquark state. The uncertainties in our sum rules are also discussed. Received: 7 September 1998 / Revised version: 5 January 2000     

Representation of Spin Group Spin（p, q）

The representation η（P, q） of spin group Spin（p, q） in any dimensional space is given by induction, and the relation between two representations, which are obtained in two kinds of inductions from Spin（p, q） to Spin（p ＋ 1, q ＋ 1） are studied.     

Supersymmetric inhomogeneous semiconductor structures and the nature of a parity anomaly in (2+1) electrodynamics

Possible inhomogeneous structures in a two-band semiconductor are classified by symmetry treatment of an effective Dirac hamiltonian. One possibility — the antiferromagnetic domain wall — reveals the parity anomaly, well-known in (2+1) QED. The anomaly is caused by the universal interface magnetic moment directed perpendicular to the wall.     

Spin dependence of electronic surface resonance scattering from W(100)

In polarized low energy electron diffraction (PLEED) from W(100) at energies of 2 to 9 eV and incident angles 15°< θ < 45°, we observe a spin-splitting of the resonance sequence of peaks which converge on the (01) beam threshold. For θ>26° the peak splitting to peak width ratio is approximately constant while for decreasing θ≤26° it increases. An anomalous spin-up-only peak appears at small θ. The nature of the spin dependent splitting is discussed within the four-beam layer multiple scattering approximation.     

Spin tests for the Ξ1 (1820) resonance

Spin tests are derived for the Ξ^1? (1820) resonance from a comparison of its two main decay modes Ξ^1? (1820) → Λ⁰K^? and Ξ^1o (1530) π^?.     

Spin resonance spectroscopy of grown-in defects in Ga(In)NP alloys

We employ the optically detected magnetic resonance (ODMR) technique to study and identify important grown-in defects in Ga(In)NP grown by molecular-beam epitaxy (MBE). Several types of defects were revealed from ODMR studies. The dominant defects were found to be related to Ga interstitials, evident form their characteristic hyperfine interaction arising from the spin interaction between the electron and the Ga nucleus. Some other as yet unidentified intrinsic defects were also found to be commonly present in the alloys. The effects of growth conditions (ion bombardment, N₂ gas flow, etc.) and post-growth rapid thermal annealing on the formation of these defects were studied in detail, shedding light on the formation mechanism of defects.     

Spin structures and the nature of the pseudogap in cuprates

The spin and charge structures formed in a Hubbard model for a finite two-dimensional cluster have been studied in the mean field approximation. The self-consistent iterative procedure reduces an uncorrelated initial spin distribution into stable structures with characteristic spectral properties. It has been shown that the density of states of the system for any doping has a sharp minimum at the Fermi level, the pseudogap. This means that the pinning of the gap at the Fermi level is not an exclusive property of a superconducting state, but is also typical of a normal state of spin glasses.     

Spin and parity of isomeric and ground states of the doubly-odd nucleus184Au

Low-spin states in doubly-odd¹⁸⁴Au have been populated in the ⁺/EC decay of¹⁸⁴Hg produced by bombarding¹⁸⁴Sm targets with an 185 MeV⁴⁰Ar beam. Radioactive Hg nuclei were transported by a He jet system. A new level scheme has been established from --t and X--t coincidence measurements. Spin and parity values I=5⁺, I =2⁺ and I=3^– were assigned to the ground state and the two isomeric states of¹⁸⁴Au, respectively. The structure of these states is discussed using B(E1) values.     

Hyperfine interactions in negative parity baryons and the ΔD35(1925) resonance

We investigate the mass and composition of the ΔD35(1925) resonance within the framework of the Isgur-Karl model. After inclusion of hyperfine effects, and with reasonable values of the parameters in the model, we find good agreement with the results of a recent phase-shift analysis by Cutkosky et al.     

Spin,parity, and multipolarity assignments and g-factor measurements using the tristan superconducting magnet and four detector coincidence apparatus

The use of a multidetector -ray coincidence system for perturbed and unperturbed -ray angular correlations at the on-line mass separator TRISTAN is described. Applications of angular correlation techniques for deducing spin and parity assignments in a variety of even-even nuclides (116_Ag 142_Ba 142_Ce 144_Ce), odd-odd nuclides (¹⁴⁴La,¹³⁸Cs,¹³²Sb) and odd-mass nuclides (¹³⁹Xe,¹⁰⁵Rh) are discussed.     

Particle masses,force constants,and Spin(8)

From a number of qualitative conjectures, the constantsm _e ,c, , and a spin(8) gauge field theory, I derive the following particle masses (quark masses are constituent masses) and force constants: up quark mass=312.7542 MeV; down quark mass=312.7542 MeV; proton mass=938.2626 MeV; neutrino masses (all types)=0; muon mass=104.76 MeV; strange quark mass=523 MeV; charmed quark mass=1989 MeV; tauon mass=1877 MeV; bottom quark mass=5631 MeV; top quark mass=129.5 GeV;W ⁺ mass=80.87 GeV;W ^– mass=80.87 GeV;W ₀ mass=99.04 GeV; fine structure constant= 1/137.036082; weak constant times the proton mass squared M _p ² =0.97×10^–5; color constant=0.6286. From the pion mass in addition, I derive the Planck mass (1–1.6)×10¹⁹ GeV, so that the gravitational constant times the proton mass squared GM _p ² (3.6–8.8)×10^–39.     

Determination of the K(1800) spin parity

A spherical harmonic moment analysis of the reactions K⁻p → K⁻π⁺n and K⁺p → K⁺π⁻Δ⁺⁺ at 13 GeV/c demonstrates the existence of a broad K^* state with mass in the vicinity of 1800 MeV and spin parity 3⁻.