Some aspects of global Lambda polarization in heavy-ion collisions

Large orbital angular momentum can be generated in non-central heavy-ion collisions, and part of it is expected to be converted into final particle's polarization due to the spin-orbit coupling. Within the framework of A Multi-Phase Transport (AMPT) model, we studied the vorticity-induced polarization of $\Lambda$ hyperons at the midrapidity region $|\eta|<1$ in Au-Au collisions at energies $\sqrt{s_{NN}}=7.7\sim200$ GeV. Our results show that the global polarization decreases with the collisional energies and is consistent with the recent STAR measurements. This behavior can be understood by less asymmetry of participant matter in the midrapidity region due to faster expansion of fireball at higher energies. As another evidence, we discuss how much the angular momentum is deposited in different rapidity region. The result supports our asymmetry argument.Comment: 6 pages, 4 figures, CPOD 2017 proceedin

Warped Brane worlds in Critical Gravity

We investigate the brane models in arbitrary dimensional critical gravity presented in [Phys. Rev. Lett. 106, 181302 (2011)]. For the model of the thin branes with codimension one, the Gibbons-Hawking surface term and the junction conditions are derived, with which the analytical solutions for the flat, AdS, and dS branes are obtained at the critical point of the critical gravity. It is found that all these branes are embedded in an AdS$_{n}$ spacetime, but, in general, the effective cosmological constant $\Lambda$ of the AdS$_{n}$ spacetime is not equal to the naked one $\Lambda_0$ in the critical gravity, which can be positive, zero, and negative. Another interesting result is that the brane tension can also be positive, zero, or negative, depending on the symmetry of the thin brane and the values of the parameters of the theory, which is very different from the case in general relativity. It is shown that the mass hierarchy problem can be solved in the braneworld model in the higher-derivative critical gravity. We also study the thick brane model and find analytical and numerical solutions of the flat, AdS, and dS branes. It is find that some branes will have inner structure when some parameters of the theory are larger than their critical values, which may result in resonant KK modes for some bulk matter fields. The flat branes with positive energy density and AdS branes with negative energy density are embedded in an $n$-dimensional AdS spacetime, while the dS branes with positive energy density are embedded in an $n$-dimensional Minkowski one.Comment: 14 pages, 7 figures, updated version, accepted by EPJ

Clinical observation on pathologic myopia CNV treated with intravitreal bevacizumab

AIM: To evaluate the efficacy and safety of intravitreal bevacizumab(Avastin)for choroidal neovascularization(CNV)in pathologic myopia(PM)by including optical coherence tomography(OCT), fluorescein angiography(FFA)and best-corrected visual acuity(BCVA). METHODS: Totally 42 eyes in 41 patients with PM CNV were divided into 2 groups randomly, experimental group(n=22)were assigned to receive intravitreal bevacizumab injections and take fufangxueshuantong capsule; control group(n=20)just took fufangxueshuantong capsule. Subjects were followed up every month after treatment. The efficacy and safety of two group were compared by ophthalmic evaluations including OCT, FFA, and BCVA. RESULTS: BCVA: BCVA in two groups was improved after 12 months. The mean number of treatments per eye, experimental group was 4.23±2.02 and control group was 1.95±1.90. There was significant difference(P<0.005). OCT: Before and after 12 months central foveal thickness(CFD)for two groups were thin,and the mean value in experimental group was 43.41±40.39μm and in control group was 22.65±20.79μm, there was significant difference(P<0.05); FFA: In experimental group CNV was completely disappeared in 20 eyes(91%), persistent in 2 eyes(9%); the control group CNV was completely disappeared in 12 eyes(60%), persistent in 8 eyes(40%). There was significant difference(P<0.05). CONCLUSION: Intravitreal bevacizumab are safe and effective treatment for most patients of CNV in PM