1,178 research outputs found

    Sub-GeV millicharge dark matter from the U(1)XU(1)_X hidden sector

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    We conduct a comprehensive study on the sub-GeV millicharge dark matter produced through the freeze-in mechanism. We discuss in general the mixing mechanism, encompassing both kinetic mixing and mass mixing, between the U(1)XU(1)_X hidden sector and the standard model, which can generate millicharge carried by the dark fermions from the hidden sector. We discuss in depth how such millicharge is generated, and clarify several misunderstandings regarding this subject in the literature. Without employing an effective field theory approach, where the photon field directly mixed with the additional U(1)U(1), we analyze a general renormalizable model and investigate the complete evolution of the hidden sector particles. Due to the substantial self-interactions among hidden sector particles, the evolution of the hidden sector temperature plays a crucial role, which is addressed concurrently with the number densities of hidden sector particles by solving a set of coupled Boltzmann equations. We thoroughly examine eight benchmark models from six distinct cases. Some of our key findings from the analysis of these benchmark models may be generalizable and applicable to broader freeze-in scenarios. We also explore the possibility that the O\mathcal{O}(keV) U(1)XU(1)_X dark photon is a viable dark matter candidate, even though it can contribute at most 5%\sim 5\% to the total observed dark matter relic density.Comment: 55 pages, 13 figure

    Clinical investigation on angle-closure glaucoma patients with cataract treated by phacoemulsification combined with trabeculectomy

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    AIM: To investigate the effectiveness of phacoemulsification with intraocular lens(IOL)implantation combined with trabeculectomy in patients with cataract and angle-closure glaucoma.<p>METHODS: In 36 cases(46 eyes)of angle-closure glaucoma with cataract, phacoemulsification with foldable IOL implantation combined with trabeculectomy was performed. Data of pre- and post-operation, including visual acuity, intraocular pressure, filtering bleb, anterior chamber depth, chamber angle, and funds were all recorded and analyzed in detail.<p>RESULTS: During the follow-up of 3 months to 2 years,visual acuity of 43 eyes(93.5%)got improved, and intraocular pressure in 44 eyes(95.7%)were controlled in normal range(<21mmHg). Mean anterior chamber depth of 35 patients(46 eyes)got deeper from 2.1mm to 3.8mm(average 2.1±0.3mm to 3.8±0.4mm)after operation, with chamber angle opened to some extent. Six eyes(13.0%)got mild to moderate corneal edema, without corneal endothelial decompensation.<p>CONCLUSION: Phacoemulsification with IOL implantation combined with trabeculectomy is an effective and safe surgical technique for patients with angle-closure glaucoma and cataract, with satisfied control of intraocular pressure, deepening of anterior chamber, opening of anterior chamber angle, and improving visual function

    Dibromidobis(1,10-phenanthroline-κ2 N,N′)cadmium(II)

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    The title compound, [CdBr2(C12H8N2)2], synthesized by the hydro­thermal reaction of Cd(CH3COO)2·2H2O with NaBr and 1,10-phenanthroline, has the CdII cation coordinated by two Br− anions and four N atoms from two 1,10-phenanthroline ligands in a distorted octa­hedral geometry. The crystal packing is stabilized by inter­molecular π–π inter­actions with centroid–centroid distances 3.572 (1) and 3.671 (1) Å together with C—H⋯Br hydrogen bonds
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