Unraveling the Rich Fragmentation Dynamics Associated with S-H Bond Fission Following Photoexcitation of H ₂S at Wavelengths ∼129.1 nm

H2S is being detected in the atmospheres of ever more interstellar bodies, and photolysis is an important mechanism by which it is processed. Here, we report H Rydberg atom time-of-flight measurements following the excitation of H2S molecules to selected rotational (JKaKc′) levels of the 1B1 Rydberg state associated with the strong absorption feature at wavelengths of λ ∼ 129.1 nm. Analysis of the total kinetic energy release spectra derived from these data reveals that all levels predissociate to yield H atoms in conjunction with both SH(A) and SH(X) partners and that the primary SH(A)/SH(X) product branching ratio increases steeply with ⟨Jb2⟩, the square of the rotational angular momentum about the b-inertial axis in the excited state. These products arise via competing homogeneous (vibronic) and heterogeneous (Coriolis-induced) predissociation pathways that involve coupling to dissociative potential energy surfaces (PES(s)) of, respectively, 1A″ and 1A′ symmetries. The present data also show H + SH(A) product formation when exciting the JKaKc′ = 000 and 111 levels, for which ⟨Jb2⟩ = 0 and Coriolis coupling to the 1A′ PES(s) is symmetry forbidden, implying the operation of another, hitherto unrecognized, route to forming H + SH(A) products following excitation of H2S at energies above ∼9 eV. These data can be expected to stimulate future ab initio molecular dynamic studies that test, refine, and define the currently inferred predissociation pathways available to photoexcited H2S molecules

Partial Wave Analysis of J/ψ→γ(K+K−π+π−)J/\psi \to \gamma (K^+K^-\pi^+\pi^-)

BES data on $J/\psi \to \gamma (K^+K^-\pi^+\pi^-)$ are presented. The $K^*\bar K^*$ contribution peaks strongly near threshold. It is fitted with a broad $0^{-+}$ resonance with mass $M = 1800 \pm 100$ MeV, width $\Gamma = 500 \pm 200$ MeV. A broad $2^{++}$ resonance peaking at 2020 MeV is also required with width $\sim 500$ MeV. There is further evidence for a $2^{-+}$ component peaking at 2.55 GeV. The non-$K^*\bar K^*$ contribution is close to phase space; it peaks at 2.6 GeV and is very different from $K^{*}\bar{K^{*}}$.Comment: 15 pages, 6 figures, 1 table, Submitted to PL

Phenomenology of Pc(4380)+, Pc(4450)+ and related states

The $P_c(4380)^+$ and $P_c(4450)^+$ states recently discovered at LHCb have masses close to several relevant thresholds, which suggests they can be described in terms of meson-baryon degrees of freedom. This article explores the phenomenology of these states, and their possible partners, from this point of view. Competing models can be distinguished by the masses of the neutral partners which have yet to be observed, and the existence or otherwise of further partners with different isospin, spin, and parity. Future experimental studies in different decay channels can also discriminate among models, using selection rules and algebraic relations among decays. Among the several possible meson-baryon pairs which could be important, one implies that the states are mixtures of isospins 1/2 and 3/2, with characteristic signatures in production and decay. A previous experimental study of a Cabibbo-suppressed decay showed no evidence for the states, and further analysis is required to establish the significance of this non-observation. Several intriguing similarities suggest that $P_c(4450)^+$ is related to the $X(3872)$ meson.Comment: 16 pages, 1 figure. Journal version (some very minor changes from arXiv v1

Measurement of CP observables in B± → D(⁎)K± and B± → D(⁎)π± decays

Measurements of CP observables in B ± →D (⁎) K ± and B ± →D (⁎) π ± decays are presented, where D (⁎) indicates a neutral D or D ⁎ meson that is an admixture of D (⁎)0 and D¯ (⁎)0 states. Decays of the D ⁎ meson to the Dπ 0 and Dγ final states are partially reconstructed without inclusion of the neutral pion or photon, resulting in distinctive shapes in the B candidate invariant mass distribution. Decays of the D meson are fully reconstructed in the K ± π ∓ , K + K − and π + π − final states. The analysis uses a sample of charged B mesons produced in pp collisions collected by the LHCb experiment, corresponding to an integrated luminosity of 2.0, 1.0 and 2.0 fb −1 taken at centre-of-mass energies of s=7, 8 and 13 TeV, respectively. The study of B ± →D ⁎ K ± and B ± →D ⁎ π ± decays using a partial reconstruction method is the first of its kind, while the measurement of B ± →DK ± and B ± →Dπ ± decays is an update of previous LHCb measurements. The B ± →DK ± results are the most precise to date

First observation of forward Z→bbˉZ \rightarrow b \bar{b} production in pppp collisions at s=8\sqrt{s}=8 TeV

The decay Z→bb¯ is reconstructed in pp collision data, corresponding to 2 fb −1 of integrated luminosity, collected by the LHCb experiment at a centre-of-mass energy of s=8 TeV. The product of the Z production cross-section and the Z→bb¯ branching fraction is measured for candidates in the fiducial region defined by two particle-level b -quark jets with pseudorapidities in the range 2.220 GeV and dijet invariant mass in the range 4520$GeV and dijet invariant mass in the range$45 < m_{jj} < 165$GeV. From a signal yield of$5462 \pm 763$$Z \rightarrow b \bar{b}$events, where the uncertainty is statistical, a production cross-section times branching fraction of$332 \pm 46 \pm 59$pb is obtained, where the first uncertainty is statistical and the second systematic. The measured significance of the signal yield is 6.0 standard deviations. This measurement represents the first observation of the$Z \rightarrow b \bar{b}$production in the forward region of$pp$ collisions

Runoff prediction under different climate scenarios in the source region of the yellow river

Climate change has great effect on water resources in the source region of the Yellow River, which affects agricultural productivity, industrial water supply and wildlife management in the whole river basin. The hydrologic characteristics of precipitation, temperature and runoff in the source region of the Yellow River are analyzed using the long-term observed data from 1961 to 2010. The trend of runoff is predicted by the multivariate linear regression method under different climate scenarios. Reasons for the changing runoff are explored from the climate change and human activities perspective

Determination and prediction of standardized ileal amino acid digestibility of wheat in broilers

ABSTRACT: This experiment evaluated the standard ileal digestibility (SID) of amino acids (AA) in 8 different sources of wheat fed to broilers and established prediction equations based on the chemical properties of wheat. A total of five hundred forty 1-day-old broilers were tested in 2 stages (from d 10 to 13 and from d 25 to 28). On d 13, 324 broilers were randomly assigned to 9 diets (6 replicate cages, 6 broilers per cage); on d 28, 216 broilers were randomly assigned to 9 diets (6 replicate cages, 4 broilers per cage). The 9 experimental diets included 8 test diets and 1 nitrogen-free diet. Titanium dioxide was added as an exogenous indicator at 0.5% of the diet. In 8 wheat samples, the mean values of total amino acids (TAA), dispensable amino acids (DAA), and indispensable amino acids (IAA) were 12.16% (CV 13.70%), 7.97% (CV 15.49%), and 4.20% (CV 11.47%). On d 13, the lowest SID of AA was Lys (86.71%), and the highest was Pro (97.98%). On d 28, the lowest SID of AA was His (81.31%), and the highest was Pro (96.83%). There was an effect of wheat source on the SID of AA except for Trp (P < 0.05); the broiler age had an effect on the SID of AA except for Tyr (P < 0.05); the SID of most AA were higher at d 13 compared to d 28. At d 13, the SID of AA was correlated with CP, NDF, and ST (P < 0.05). At d 28, the SID of AA was correlated with EE, Ash, ADF, and NDF (P < 0.05). The R2 value of stepwise regression equations to predict the SID of AA at d 13 was highest for Leu (R2 = 0.972), lowest for Asp (R2 = 0.785); at d 28 was highest for Gly (R2 = 0.995), lowest for His (R2 = 0.678). In conclusion, this experiment showed that the chemical properties of wheat can be used to establish accurate equations for predicting the SID of AA. This made it more efficient to obtain the SID of AA for wheat

Magnetic anisotropies in epitaxial Fe3O4/GaAs(100) patterned structures

10.1063/1.4897963AIP Advances41010711

Low-field magnetoresistance in nanosized La0.7Sr0.3MnO3/Pr0.5Sr 0.5MnO3 composites

10.1063/1.1350602Applied Physics Letters7881110-1112APPL