Dispersive Contribution of ρ(1450,1700) Decays and X(1576)

We study whether the broad enhancement X（1576） arises from the final state interaction （FSI） of p（1450, 1700）→p^＋ p^- →K^＋ K^-decay,Both the absorptive and dispersive contributions of the above amplitudes are considered since the intermediate states are very close to p（1450, 1700）. AThe same mechanism leads to a similar enhancement around 1580 MeV in the π^＋ π^- specturm in the J/ψ →π^0 π^＋ π^- channel, which can be used to test whether X（1576） can be ascribed to the FSI effect ofp（1450, 1700） → p^＋ p^-.     

Confirmation of the X(1835) and observation of the resonances X(2120) and X(2370) in J/ψ→γπ+π-η'

With a sample of (225.2±2.8)×10(6) J/ψ events registered in the BESIII detector, J/ψ→γπ(+)π(-)η(') is studied using two η(') decay modes: η(')→π(+)π(-)η and η(')→γρ(0). The X(1835), which was previously observed by BESII, is confirmed with a statistical significance that is larger than 20σ. In addition, in the π(+)π(-)η(') invariant-mass spectrum, the X(2120) and the X(2370), are observed with statistical significances larger than 7.2σ and 6.4σ, respectively. For the X(1835), the angular distribution of the radiative photon is consistent with expectations for a pseudoscalar.     

The pure rotational spectrum of ZnS (XΣ)

The pure rotational spectrum of ZnS (X¹Σ⁺) has been measured using direct-absorption millimeter/sub-millimeter techniques in the frequency range 372-471 GHz. This study is the first spectroscopic investigation of this molecule. Spectra originating in four zinc isotopologues (⁶⁴ZnS, ⁶⁶ZnS, ⁶⁸ZnS, and ⁶⁷ZnS) were recorded in natural abundance in the ground vibrational state, and data from the v = 1 state were also measured for the two most abundant zinc species. Spectroscopic constants have been subsequently determined, and equilibrium parameters have been estimated. The equilibrium bond length was calculated to be r_e ∼ 2.0464 Å, which agrees well with theoretical predictions. In contrast, the dissociation energy of D_E ∼ 3.12 eV calculated for ZnS, assuming a Morse potential, was significantly higher than past experimental and theoretical estimates, suggesting diabatic interaction with other potentials that lower the effective dissociation energy. Although ZnS is isovalent with ZnO, there appear to be subtle differences in bonding between the two species, as suggested by their respective force constants and bond length trends in the 3d series.     

Vibrational spectra of Te(OH)6·X2SO4 (X = Tl,Na)

The IR and Raman spectra of Te(OH)₆·X₂SO₄ (X = Tl, Na) have been recorded and analysed. The splitting of the nondegenerate mode of the sulphate ion suggests factor group interaction between the vibrating ions. The linear distortion of the sulphate ions is found to be more in Te(OH)₆·Na₂SO₄ than in Te(OH)₆·Tl₂SO₄. The tellurate ion seems to be less distorted than the sulphate ion. The appearance of Raman inactive modes of the tellurate ion indicate the presence of strain produced by the crystalline field. The anions are also found to coexist independently.     

Effect of γ-radiation on TL,ESR and evaluation of trapping parameters of K2Ca(SO4)2:X (X = Dy or Eu) phosphors

ABSTRACT

The present phosphor K₂Ca(SO₄)_2, doped by dysprosium and europium, is synthesized by the solid-state diffusion method. The doping concentration varied from 0.1 to 0.5?mol% by weight. A phosphor is studied for X-ray powder diffraction, surface morphology analytical scanning electron microscopy and analyzed by energy-dispersive X-ray spectroscopy. The prepared phosphor K₂Ca(SO₄)_2, doped by Dy and Eu, has been characterized for thermoluminescence (TL) glow curve, showing maximum peak temperatures at 176°C and at 200°C, respectively. TL peak intensity of K₂Ca(SO₄)₂: Dy and Eu was compared with the standard TLD CaSO₄:Dy phosphor. Both phosphors show the dose linearity ranging from 20 to 240?Gy doses of γ-rays of ⁶⁰Co source at room temperature. Negligible fading has been observed when irradiated with γ-rays and stored for 60 days without taking any care from sunlight. The TL materials were used in powder forms. The linearity of ESR response with dose for powder forms of K₂Ca(SO₄)₂: Dy was also studied using the signals at g?=?2:0039 (SO₃^?) and at g?=?2:02282 (SO₄^?). It was observed that the range of linearity of dose response extended between 20 and 240?Gy. Kinetic parameters have been calculated using three different methods: Chen's peak shape method, various heating rate method and initial rise method. To study the heating rate method, the glow curve was recorded for the heating rate as 1°C, 3°C, 5°C, 7°C, 9°C each time. Electron spin resonance (ESR) shows the ionic radical formation during γ-irradiation, which is responsible for TL. The effect of temperature and microwave power on the ESR signal was also studied.     

Study of X(5568) in a unitary coupled-channel approximation of BK and B_sπ

The potential of the B meson and the pseudoscalar meson is constructed up to the next-to-leading order Lagrangian, and then the BK and B_sπ interaction is studied in the unitary coupled-channel approximation. A resonant state with a mass about 5568 MeV and J~P= 0~+is generated dynamically, which can be associated with the X(5568) state announced by the D0 Collaboration recently. The mass and the decay width of this resonant state depend on the regularization scale in the dimensional regularization scheme, or the maximum momentum in the momentum cutoff regularization scheme. The scattering amplitude of the vector B meson and the pseudoscalar meson is calculated, and an axial-vector state with a mass near 5620 MeV and J~P= 1~+is produced. Their partners in the charm sector are also discussed.     

Vibrational analysis of the (B 2 П→X 2 П) system of NS

A few red degraded bands attributable to NS have been reported earlier byFowler andBarker, Dressler andBarrow et al, and they occur in the same region (2300 to 2700 Å) as the bands of the known systems (C ² ∑ ⁺?X ² П) and (A ² Δ?X ² П). Measurements made on the heads of some of these weak bands ledBarrow et al. to believe that these bands may form a system analogous to theβ-system of NO and be due to a² П-² П transition. The spectrum of NS has now been studied in a little more detail by means of an uncondensed discharge through dry nitrogen and sulphur vapour in the presence of argon and thirty three bands belonging to this system have been recorded in the region 2280 to 2760 Å. It has been found possible to represent the band heads by means of the equation

$$^v {\text{head}} {\text{ = }} \left. {_{43182 \cdot 5}^{{\text{43311}} \cdot {\text{5}}} } \right\}_{ - [1219 \cdot 20(v'' + \tfrac{1}{2}) - 7 \cdot 48(v'' + \tfrac{1}{2})^2 ].}^{ + [761 \cdot 04(v' + \tfrac{1}{2}) - 5 \cdot 10(v' + \tfrac{1}{2})^2 ]}$$     

Optimisation of the pulse duration of a discharge-pumped XeF(B→X) excimer laser

In an x-ray preionised XeF(BX) discharge-excited laser driven by a magnetic-spiker sustainer circuit with a magnetic pulse compressor the influence of the various parameters on the optical pulse duration was experimentally investigated. Laser pulses at = 351 nm with a duration of 212 ns (FWHM) have been achieved in a NF₃/Xe/Ne mixture by using very low (0.25 mbar) NF₃ partial pressures in a total gas pressure of 2.5 bar and with a high-reflecting output coupling mirror.     

The sub-millimeter and Fourier transform microwave spectrum of HZnCl (X Σ)

The pure rotational spectrum of HZnCl (X ¹Σ⁺) has been recorded using sub-millimeter direct-absorption methods in the range of 439-540 GHz and Fourier transform microwave (FTMW) techniques from 9 to 39 GHz. This species was produced by the reaction of zinc vapor and chlorine gas with H₂ or D₂ in a d.c. glow discharge for the sub-millimeter studies. In the FTMW measurements, HZnCl was created in a discharge nozzle from Cl₂ and (CH₃)₂Zn. Between 5 and 10 rotational transitions were measured in the sub-millimeter regime for four zinc and two chlorine isotopologues; four transitions were recorded with the FTMW machine for the main isotopologue, each consisting of several chlorine hyperfine components. The data are consistent with a linear molecule and a ¹Σ⁺ ground electronic state. Rotational and chlorine quadrupole constants were established from the spectra, as well as an r_m⁽²⁾ structure. The Zn-Cl and Zn-H bond lengths were determined to be 2.0829 and 1.5050 Å, respectively; in contrast, the Zn-Cl bond distance in ZnCl is 2.1300 Å, longer by ∼0.050 Å. The zinc-chlorine bond distance therefore shortens with the addition of the H atom. The ³⁵Cl electric quadrupole coupling constant of eQq = −27.429 MHz found for HZnCl suggests that this molecule is primarily an ionic species with some covalent character for the Zn-Cl bond.     

A photoelectron spectroscopic study of the second ionisation of the CF(X2Π) radical

The CF(X²Π) radical has been re-investigated with vacuum ultraviolet photoelectron spectroscopy. Two bands were observed and assigned to the ionisations CF⁺(X¹Σ⁺)←CF(X²Π) and CF⁺(a³Π)← CF(X²Π). The first band, which has been observed previously, has an adiabatic ionisation energy of (9.11±0.02) eV and a vertical ionisation energy of (9.55±0.02) eV. For the second band, three vibrational components were observed with the first, the most intense, at an ionisation energy of (13.94±0.02) eV. Analysis of the vibrational structure in the two observed bands allowed ω_e and r_e to be determined as 1810±30 cm⁻¹ and 1.154±0.005 Å, respectively for the first ionic state, CF⁺(X¹Σ⁺), and 1614±30 cm⁻¹ and 1.213±0.005 Å, respectively for the second ionic state, CF⁺(a³Π). Comparison of the ionisation energies and spectroscopic constants obtained has been made with values obtained from recent multi-reference configuration interaction calculations.     

Cartesian Dynamics of Simple Molecules X Linear Quadratomics (C∞v Symmetry)

The vibrations of linear ABC₂ type molecules with C_∞V point group are analysed in terms of Cartesian co-ordinates. Algebraic expressions for the three stretching and two bending normal mode frequencies are derived in terms of longitudinal and transverse force constants, atomic masses and bond lengths. Values of non-valence interaction parameters are transferred from A₂B₂ (D_∞h) molecules, and values of the principal force constants are adjusted to reproduce the observed frequencies for a number of asymmetric halogen derivatives of acetylene. Normal mode frequencies of various isotopic species are also calculated. The nature of the computed eigenvectors for these molecules is briefly discussed. It is found that the carbon-carbon and carbon-hydrogen valence interactions remain approximately constant for these molecules, whereas the carbon-halogen bonds show a weakening trend with increasing halogen mass.     

Determination of the electron phonon coupling and the superconducting gap in β-(BEDT-TTF)2X crystals (X=I3, IAuI)

We performed point-contact and tunneling measurements on the organic superconductors -(BEDT-TTF)₂I₃ and -(BEDT-TTF)₂IAuI, in the normal and superconducting states. The point-contact measurement in the normal state provides the Eliashberg function ²()F (). This function has maxima at 4 and 15 mV, as well as a sharp peak at 1 mV which seems to indicate a very soft phonon strongly coupled to the electrons. The measurements in the superconducting state provide the superconducting gap, which for the tunneling measurements has a value 2/k_B T_c4, just slightly above the BCS value.     

Formation of 8He in the 9Be(π–, p)X and 10B(π–, pp)X Stopped Pion Absorption Reactions

JETP Letters - The structure of levels of the 8He heavy helium isotope has been studied in the 9Be $$({{\pi }^{ - }},p)X$$ and 10B $$({{\pi }^{ - }},pp)X$$ stopped pion absorption reactions....     

C(γ,η)X Reactions and Properties of N*(1535) in Nuclei

The η photon production reaction on nuclei is studied by employing N^*(1535) resonance model. The parameters of the model are extracted by using experimental data of N^* decay channels and fitting γp→ηp reaction cross section. The result shows that the theoretical values are in good agreement with experimental data if M_N*=1550MeV. The total cross section of the η photoproduction on ¹²C is calculated. We find that the width of N^*(1535) in nuclei increases because of corrections of many-body effects, and the interaction between N^* and nuclei has the feature of repulsion.     

Time-dependent quantum wave packet and quasiclassical trajectory studies of the Au(2S) + H2(X1∑+g) → AuH(X1∑+g) + H(2S) reaction

The time-dependent quantum wave packet (TDWP) and quasiclassical trajectory calculations (QCT) are carried out for the Au(²S) + H₂(X¹∑⁺_g) → AuH(X¹∑⁺_g) + H(²S) reaction on a global potential energy surface. The reaction probabilities at a series of J values, integral cross sections (ICSs) and differential cross sections of the title reaction are calculated by the TDWP method. For reaction probabilities, there are a mass of sharp oscillations at low collision energy, which can be attributed to resonances supported by the potential well. Due to the endothermicity of the title reaction, the total ICS shows a threshold about 1.53 eV. In order to further investigate the reactive mechanism, the lifetime of complex is calculated by QCT method. At the low collision energy, most intermediate complexes are long lived, which implies that the reaction is governed by indirect reactive mechanism. With the collision energy increasing, the direct reactive mechanism occupies the dominant position. Due to the change of the reactive mechanism, the angular distribution shifts toward the forward direction with collision energy increasing. The isotopic variant, Au + D₂→AuD + D reaction, is also calculated by TDWP method. The calculated reaction probabilities and ICSs show that the isotope effect reduces the reactivity.     

Influence of ro-vibrational and isotope effects on the dynamics of the C(3 P)+ OD(X 2Π) → CO(X 1 Σ+) + D(2 S) reaction

The C(³ P)+OD(X ²Π) reaction has been studied by means of quantum mechanical real wave packet (RWP) and quasiclassical trajectory (QCT) methodologies on the ground potential energy surface of Zanchet et al. [J. Phys. Chem. A 110, 12017 (2006)]. Initial state selected total reaction probabilities at J?=?0 total angular momentum have been calculated for a wide range of collision energies. Product state-resolved integral cross-sections at selected collision energies and excitation functions have been determined from the RWP calculations using the J-shifting approximation and from QCT calculations. State-specific and thermal rate coefficients have been calculated using both methodologies up to 500 K. The effect of reagent rotational excitation on the dynamics for the C(³ P)+OH(X ²Π) and C(³ P)+OD(X ²Π) reactions has been investigated and interesting discrepancies between the QCT and RWP results have been found. The RWP results are found to be in an overall good agreement with the corresponding QCT results, although the QCT integral cross-section and rate coefficients are slightly smaller than those obtained from the RWP calculations.