Charm-strange baryon strong decays in a chiral quark model

The strong decays of charm-strange baryons up to N=2 shell are studied in a chiral quark model. The theoretical predictions for the well determined charm-strange baryons, $\Xi_c^*(2645)$, $\Xi_c(2790)$ and $\Xi_c(2815)$, are in good agreement with the experimental data. This model is also extended to analyze the strong decays of the other newly observed charm-strange baryons $\Xi_c(2930)$, $\Xi_c(2980)$, $\Xi_c(3055)$, $\Xi_c(3080)$ and $\Xi_c(3123)$. Our predictions are given as follows. (i) $\Xi_c(2930)$ might be the first $P$-wave excitation of $\Xi_c'$ with $J^P=1/2^-$, favors the $|\Xi_c'\ ^2P_\lambda 1/2^->$or$|\Xi_c'\ ^4P_\lambda 1/2^->$state. (ii)$\Xi_c(2980)$might correspond to two overlapping$P$-wave states$|\Xi_c'\ ^2P_\rho 1/2^->$and$|\Xi_c'\ ^2P_\rho 3/2^->$, respectively. The$\Xi_c(2980)$observed in the$\Lambda_c^+\bar{K}\pi$final state is most likely to be the$|\Xi_c'\ ^2P_\rho 1/2^->$state, while the narrower resonance with a mass$m\simeq 2.97$GeV observed in the$\Xi_c^*(2645)\pi$channel favors to be assigned to the$|\Xi_c'\ ^2P_\rho 3/2^->$state. (iii)$\Xi_c(3080)$favors to be classified as the$|\Xi_c\ S_{\rho\rho} 1/2^+>$state, i.e., the first radial excitation (2S) of$\Xi_c$. (iv)$\Xi_c(3055)$is most likely to be the first$D$-wave excitation of$\Xi_c$with$J^P=3/2^+$, favors the$|\Xi_c\ ^2D_{\lambda\lambda} 3/2^+>$state. (v)$\Xi_c(3123)$might be assigned to the$|\Xi_c'\ ^4D_{\lambda\lambda} 3/2^+>$,$|\Xi_c'\ ^4D_{\lambda\lambda} 5/2^+>$, or$|\Xi_c\ ^2D_{\rho\rho} 5/2^+>$state. As a by-product, we calculate the strong decays of the bottom baryons$\Sigma_b^{\pm}$,$\Sigma_b^{*\pm}$and$\Xi_b^*$, which are in good agreement with the recent observations as well.Comment: 15 pages, 9 figure

Zinc 2-((2-(benzoimidazol-2-yl)quinolin-8-ylimino)methyl)phenolates : synthesis, characterization and photoluminescence behavior

A series of 2-(2-(1H-benzoimidazol-2-yl)quinolin-8-yliminomethyl)phenol derivatives and their zinc complexes (C1 – C5) were synthesized and fully characterized. The molecular structure of the representative complex C2 was determined by single crystal X-ray diffraction, which revealed that the zinc was five-coordinated with the tetra-dentate ligand and a methanol bound to the metal afford a distorted square-pyramidal geometry. The UV-Vis absorption and fluorescence spectra of the organic compounds and their zinc complexes were measured and investigated in various solvents such as methanol, THF, dichloromethane, and toluene; significant influences by solvents were observed on their luminescent properties; red-shifts for the zinc complexes were clearly observed in comparisons to the free organic compounds

From crustal anatexis to mantle melting in the Variscan orogen of Corsica (France): SIMS U-Pb zircon age constraints

International audienceHigh-precision SIMS U-Pb zircon age determinations are conducted in this study on migmatites and Mg-K magmatic suites from the Variscan orogen of Corsica (France). Zircons from leucosomes of four migmatites yield consistent crystallization ages of ca. 345 Ma. Four Mg-K granitoid rocks and one monzogabbro enclave from the Calvi-IIe Rousse pluton of NW Corsica yield indistinguishable U-Pb zircon ages of ca. 330 Ma. These new SIMS zircon U-Pb dating results indicate that the regional crustal anatexis under amphibolite-facies condition occurred synchronously at ca. 345 Ma throughout the Corsican Variscan chain. There is a ca. 15 m.y. time interval between anatexis of the thickened crust and partial melting of the metasomatized mantle and overlying crust to form the Mg-K rock suites. In combination with the previous dating results for the high-temperature and high-pressure granulite-facies metamorphism, three major discrete tectonothermal events at ca. 360 Ma, ca. 345 Ma, and ca. 330 Ma are acknowledged. We argue for a slab break-off model accounting for thermal and mechanical evolution of the crust within the Variscan orogen of Corsica. A tearing of the subducting oceanic lithosphere initiates the asthenosphere rise to fill the void and causes the granulite-facies metamorphism of the overlying continental crust at ca. 360 Ma. Final breaking of the subducting oceanic lithosphere results in exhumation of the subducted crust to the thickened lower to middle crustal-level. Internal radiogenic heating causes crust-scale migmatization at ca. 345 Ma. Slab break-off and foundering enhance the rise of hot asthenosphere, resulting in conducted thermal perturbation that leads to melting of the metasomatised enriched mantle lithosphere to form Mg-K mafic-granitoid magmatism at ca. 330 Ma

Provenance evolution of age‐calibrated strata reveals when and how South China Block collided with Gondwana

The South China Block (SCB) has been regarded by many as an integral part of Gondwana, but proposed timing and processes for its accretion to Gondwana vary and remain contentious, largely owing to the lack of reliable Pan‐African age paleomagnetic data and tectono‐magmatic records from the SCB. Integrated in situ U‐Pb ages and Hf‐O isotope analyses of detrital zircons from geochronologically well‐calibrated Ediacaran‐Cambrian sedimentary rocks of western SCB reveal age populations of 2.51, 1.85, 1.20, 0.80, and 0.52 Ga. Detrital zircon age spectra indicate a major tectonic transition for the SCB during 0.56–0.54 Ga, interpreted to reflect the beginning of the collision between SCB‐Indochina and NW India blocks. The collisional event lasted until early Ordovician, leading to the suturing of the SCB‐Indochina to the northern margin of East Gondwana