Evidence for two strangeonium resonances with JPC=1++ and 1+− in K−p interactions at 11 GeV/c

The results of a partial wave analysis of the low mass KK̄π system produced in the reactions K⁻p→K⁰_sK^±π^±Λ at 11 GeV/c using the LASS spectrometer are presented. Evidence is given for two ss̄ axial-vector meson states: one with quantum numbers J^PC = 1⁺⁺, mass ∼ 1530 MeV/c², and width ∼ 100 MeV/c², and the other with quantum numbers J^PC=1⁺⁻, mass ∼ 1380 MeV/c², and width ∼ 80 MeV/c². These states are good candidates to be the mostly strangeonium members of the ground state 1⁺⁺ and 1⁺⁻ nonets predicted by the quark model.     

Identification of a 3+ state in16O and evidence for a (1f 7/2 1p 1 2/−1 ) component in its wave function

Excitation functions and angular distributions for the elastic scattering of protons on¹⁵N and the reactions¹⁵N(p, α ₀)¹²C and¹⁵N(p,α ₁)¹²C^* were measured in the proton energy range of 2.50?5.14 MeV (E _x (¹⁶O)=14.47?16.94 MeV). Besides known resonances two new ones were found at 16.46 and 16.82MeV. For the latterJ ^?=3⁺ is assigned using the compound nucleus theory. The wave function of this state contains a (1f _7/2 1p ₁ ^2/?1 )₃-particle-hole-component. Earlier spin parity assignments of other resonances are discussed.     

Parameterization of a potential function for the Ca2+ −Ne and Ca2+ −N2 interactions using high-level ab initio data

Ab initio calculations have been carried out at the CCSD(T)/aug-cc-pVTZ level on di-nitrogen and neon interacting with a calcium (II) cation. The interaction of nitrogen with the Ca²⁺ cation is examined for end-on and side-on approaches. The two adjustable parameters in the TrAZ potential (A ^Ca2+-Ne , b ^Ca2+-Ne ) are fitted to the Ca²⁺-Ne potential energy curve and combination rules are then applied in reverse to get A ^Ca2+-Ca2+ , b ^Ca2+-Ca2+ . Combining these with values of A^NN, 6^NN enables the Ca²⁺-N₂ potential energy curves to be predicted a priori. Agreement with the ab initio data is found to improve dramatically when the anisotropy of the nitrogen polarizability is included in the induced interaction energy. Other combination rules are tried but are not found to have an impact on the agreement between the a priori potential and the ab initio data     

Evidence for A JPC=4++ KK state at ∼2.2 GeV/c2 from K−p interactions at 11 GeV/c

Data from the reaction K⁻p→K⁻K⁺Λ at 11 GeV/c have been obtained in the LASS spectrometer at SLAC. A spherical harmonic moments analysis of the K⁻K⁺ system provides evidence for a rather narrow J^PC=4⁺⁺ state at ∼2.2 GeV/c². Relevant data from the reaction K⁻p→K⁰_sK⁰_sΛ in the present experiment are shown also, and comparisons made to results from MARK III and GAMS in this mass region.     

Study of the production of a strange (S = −1) dibaryon in the interactions of K− and π+ on deuterium below 1.5GeV/c

The production of a strange dibaryonic system called H⁺₁ (M = 2.13 GeV/c², S = ?1), has been studied with a missing mass spectrometer, at the CERN Proton Synchrotron, in the reaction K^?d → π^?H⁺₁ and in the line-reversed reaction π⁺d → K⁺H⁺₁ between 0.9 and 1.4 GeV/c.The reactions

$\text{K}{}^{\mathrm{?}}\text{d}\text{→ π}{}^{\mathrm{?}}\text{X}{}^{\mathrm{+}}$

,

$\text{π}{}^{\mathrm{<mtext>d</mtext>}}\text{→}\text{K}{}^{\mathrm{+}}\text{X}{}^{\mathrm{+}}$

,have been studied in a missing mass spectrometer at CERN. The experiment (PS159) is well adapted to search for a signal in the missing mass X⁺ (B = 2, S = ?1) produced in the backward c.m.s. direction, between 2.0 and 2.3 GeV/c². The two reactions have been analysed at three different beam settings: 1.4, 1.06 and 0.92 GeV/c for reaction (1) and 1.4, 1.2 and 1.06 GeV/c for reaction (2).     

Evidence for a double charge transfer contribution to SERS in the Ag/Ag (CN)2− system

Using a square wave potential perturbation and monitoring the Raman intensity in parallel, the potential dependence of Ag(CN)₂⁻ spectra was studied with different exciting wavelengths. A double peak structure was found for the C-N stretch frequency both peaks having different excitation characteristics. In addition, the quenching rate of ad-complexes was measured at negative potentials together with the activation energy. From E_A = 75 kJ mol⁻, the energy of an acceptor level can be estimated located about 3 eV above E_F. This level presumably corresponds to the Ag 5s orbital which is shifted upwards due to the interaction with the ligands of the ad-complex. Since the CN⁻ 5σ or 1π orbitals form a donor level, the possibility of a double charge transfer contribution to the SERS enhancement exists.     

The infrared spectrum of 13C2HD between 100 and 2100 cm−1: a global fit for the bending states up to υ 4 + υ 5 = 3

The fundamental bending ro-vibrational bands and a number of overtone, combination and hot bands of ¹³C₂HD have been recorded by Fourier transform infrared spectroscopy in the range 450–2100 cm^?1. In addition, the ν ₅ ← ν ₄ band, centred at 164.65 cm^?1, has been identified in the spectrum of ¹³C₂H₂. The data were analysed simultaneously in a global fit that has provided very accurate rotational and vibrational parameters for the ground and vibrationally excited states.     

A 480 ms isomeric 29/2−-state of the(p_{1/2}^{ - 2} )_{0^ + } f_{5/2}^{ - 1} (i_{13/2}^{ - 2} )_{12^ + } configuration in203Pb

A new, 480 ms, 29/2^? isomeric level has been found in²⁰³Pb at an excitation energy of 2950.1 keV by bombarding²⁰⁴Hg with α-particles in the energy range 45–55 MeV using the Stockholm 225-cm cyclotron. This 29/2^? state is suggested to be mainly due to the configuration (p ₁ ^2/?2 f ₅ ^2/?1 i ₁₃ ^2/?2 )₁₂. The 29/2^? state decays predominantly by a 153.4 keV M2 transition to a 23/2^? level and by a 1027.5 keV M4 transition to a 21/2⁺ level, followed by two E2 transitions of energies 258.6 keV and 838.7 keV, respectively, to the previously known 13/2⁺, 6.4 s isomeric level. The decay scheme of the 29/2^? isomeric state is based on experimental information obtained from total and delayedγ-ray intensities,γγ-coincidences, excitation functions, lifetime and delayed conversion electron measurements. The presence of the 29/2^? level confirms an essential and expected feature of the shell model for five neutron holes added to the²⁰⁸Pb-core.