Implication of BaBar's new data on the Ds1(2710)D_{s1}(2710) and DsJ(2860)D_{sJ}(2860)

The strong decays of the $D_{s1}(2710)$ and $D_{sJ}(2860)$ are investigated in the framework of the $^3P_0$ model. Its decay properties newly reported by the BaBar Collaboration can be reasonably accounted for in the presence of the $D_{s1}(2710)$ being a mixture of the $D_s(2 ^3S_1)$ and $D_s(1 ^3D_1)$. The orthogonal partner of the $D_{s1}(2710)$ is expected to have a mass of about $2.66\sim 2.9$ GeV in quark models and a width of about $40\sim 60$ MeV in the $^3P_0$ model. The predicted decay properties turn out to be consistent with the BaBar's new data in both the orthogonal partner of the $D_{s1}(2710)$ and the $D_s(1 ^3D_3)$ interpretations for the $D_{sJ}(2860)$. The available experimental information is not enough to distinguish these two possibilities. The $E1$ radiative transitions of the $D_{s1}(2710)$ and $D_{sJ}(2860)$ are also studied. We tend to conclude that the $D_{s1}(2710)$ can be identified as a mixture of the $D_s(2 ^3S_1)$ and $D_s(1 ^3D_1)$, and the $D_{sJ}(2860)$ could be either the orthogonal partner of the $D_{s1}(2710)$ or the $D_s(1 ^3D_3)$. Further experimental information on the $D_{sJ}(2860)$ in the $D_s\eta$, $D^\ast_s\eta$, and $DK^\ast$ channels is needed.Comment: 13 pages, 2 figures, version accepted for publication in Phys. Rev.

Properties of the scalar mesons f0(1370)f_0(1370), f0(1500)f_0(1500) and f0(1710)f_0(1710)

In the three-state mixing framework, considering the possible glueball components of $\eta$ and $\eta^\prime$, we investigate the hadronic decays of $f_0(1370)$, $f_0(1500)$ and $f_0(1710)$ into two pseudoscalar mesons. The quarkonia-glueball content of the three states is determined from the fit to the new data presented by the WA102 Collaboration. We find that these data are insensitive to the possible glueball components of $\eta$ and $\eta^\prime$. Furthermore, we discuss some properties of the mass matrix describing the mixing of the isoscalar scalar mesons.Comment: Latex 14 pages including 1 eps figur

The kHz QPOs as a probe of the X-ray color-color diagram and accretion-disk structure for the atoll source 4U 1728-34

We have taken the kHz QPOs as a tool to probe the correlation between the tracks of X-ray color-color diagram (CCD) and magnetosphere-disk positions for the atoll source 4U 1728-34, based on the assumptions that the upper kHz QPO is ascribed to the Keplerian orbital motion and the neutron star (NS) magnetosphere is defined by the dipole magnetic field. We find that from the island to the banana state, the inner accretion disk gradually approaches the NS surface with the radius decreasing from r ~33.0km to ~15.9 km, corresponding to the magnetic field from B(r) ~4.8*10^6 G to ~4.3*10^7 G. In addition, we note the characteristics of some particular radii of magnetosphere-disk -r are: firstly, the whole atoll shape of the CCD links the disk radius range of ~15.9 - 33.0 km, which is just located inside the corotation radius of 4U 1728-34 -r_co ( ~34.4 km), implying that the CCD shape is involved in the NS spin-up state. Secondly, the island and banana states of CCD correspond to the two particular boundaries: (I)-near the corotation radius at r ~27.2 - 33.0 km, where the source lies in the island state; (II)-near the NS surface at r ~15.9 - 22.3 km, where the source lies in both the island and banana states. Thirdly, the vertex of the atoll shape in CCD, where the radiation transition from the hard to soft photons occurs, is found to be near the NS surface at r ~16.4 km. The above results suggest that both the magnetic field and accretion environment are related to the CCD structure of atoll track, where the corotation radius and NS hard surface play the significant roles in the radiation distribution of atoll source.Comment: 6 pages, 3 figures, 1 table, accepted by Astronomy & Astrophysic

Capillarity-driven dynamics of water–alcohol mixtures in nanofluidic channels

We investigated the spontaneous capillarity-driven filling of nanofluidic channels with a thickness of 6 and 16 nm using mixtures of ethanol and water of variable composition. To improve the visibility of the fluid, we embedded metal mirrors into the top and bottom walls of the channels that act as a Fabry–Pérot interferometer. The motion of propagating liquid–air menisci was monitored for various concentrations in transmission with an optical microscope. In spite of the visible effects of surface roughness and different affinity of water and ethanol to the channel walls, the dynamics followed the classical t 1/2—dependence according to Lucas and Washburn. While the prefactor of this algebraic relation falls short of the expectations based on bulk properties by 10–30%, the relative variation between mixtures of different composition follows the expectations based on the bulk surface tension and viscosity, implying that—despite the small width of the channels and the large surface-to-volume ratio—specific adsorption or chemical selectivity effects are not relevant. We briefly discuss the impact of surface roughness on our experimental results

The η(2225)\eta(2225) observed by the BES Collaboration

In the framework of the $^3P_0$ meson decay model, the strong decays of the $3 ^1S_0$ and $4 ^1S_0$ $s\bar{s}$ states are investigated. It is found that in the presence of the initial state mass being 2.24 GeV, the total widths of the $3 ^1S_0$ and $4 ^1S_0$ $s\bar{s}$ states are about 438 MeV and 125 MeV, respectively. Also, when the initial state mass varies from 2220 to 2400 MeV, the total width of the $4 ^1S_0$ $s\bar{s}$ state varies from about 100 to 132 MeV, while the total width of the $3 ^1S_0$ $s\bar{s}$ state varies from about 400 to 594 MeV. A comparison of the predicted widths and the experimental result of $(0.19\pm 0.03^{+0.04}_{-0.06})$ GeV, the width of the $\eta(2225)$ with a mass of $(2.24^{+0.03+0.03}_{-0.02-0.02})$ GeV recently observed by the BES Collaboration in the radiative decay $J/\psi\to\gamma\phi\phi\to\gamma K^+K^-K^0_SK^0_L$, suggests that it would be very difficult to identify the $\eta(2225)$ as the $3 ^1S_0$ $s\bar{s}$ state, and the $\eta(2225)$ seams a good candidate for the $4 ^1S_0$ $s\bar{s}$ state.Comment: 14 pages, 3 figures, typos corrected, Accepted by Physical Review