4,073 research outputs found

    Bs(d)Bˉs(d)B_{s(d)}-\bar{B}_{s(d)} Mixing and Bsμ+μB_s\to\mu^+\mu^- Decay in the NMSSM with the Flavour Expansion Theorem

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    In this paper, motivated by the observation that the Standard Model predictions are now above the experimental data for the mass difference ΔMs(d)\Delta M_{s(d)}, we perform a detailed study of Bs(d)Bˉs(d)B_{s(d)}-\bar{B}_{s(d)} mixing and Bsμ+μB_s\to\mu^+\mu^- decay in the Z3\mathbb{Z}_3-invariant NMSSM with non-minimal flavour violation, using the recently developed procedure based on the Flavour Expansion Theorem, with which one can perform a purely algebraic mass-insertion expansion of an amplitude written in the mass eigenstate basis without performing any diagrammatic calculations in the interaction/flavour basis. Specifically, we consider the finite orders of mass insertions for neutralinos but the general orders for squarks and charginos, under two sets of assumptions for the squark flavour structures (\textit{i.e.}, while the flavour-conserving off-diagonal element δ33LR\delta_{33}^\text{LR} is kept in both of these two sectors, only the flavour-violating off-diagonal elements δ23LL\delta_{23}^\text{LL} and δi3RR\delta_{i3}^\text{RR} (i=1,2i=1,2) are kept in the \text{LL} and \text{RR} sectors, respectively). Our analytic results are then expressed directly in terms of the initial Lagrangian parameters in the interaction/flavour basis, making it easy to impose the experimental bounds on them. It is found numerically that the NMSSM effects with the above two assumptions for the squark flavour structures can accommodate the observed deviation for ΔMs(d)\Delta M_{s(d)}, while complying with the experimental constraints from the branching ratios of Bsμ+μB_s\to \mu^+ \mu^- and BXsγB\to X_s\gamma decays.Comment: 48 pages, 7 figures, and 2 tables; More discussions and references added, final version to be published in JHE

    2,10-Dibromo-6-isobutyl-6-methyl­dibenzo[d,f][1,3]dioxepine

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    In the crystal structure of the title compound, C18H18Br2O2, the two benzene rings of the bridged biphenyl unit are twisted by 38.0 (1)°

    3,9-Dibromo-5,7-dihydro­dibenzo[c,e]oxepine

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    The title compound, C14H10Br2O, is a biphenyl derivative containing a –CH2—O—CH2– bridge in the 2,2′-position. The compound displays a twisted conformation with the two benzene rings making a dihedral angle of 45.02 (5)°, while the central seven-membered ring is in a boat conformation. The mol­ecule lies on a crystallographic twofold axis of symmetry passing through the O atom and bis­ecting the 1,1′ C—C bond

    2,10-Dibromo-6,6-dimethyl­dibenzo[d,f][1,3]dioxepine

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    In the crystal structure of the title compound, C15H12Br2O2, which was synthesized from 2,10-dibromo-2,2′-dihydroxy­biphenyl and 2,2-dimethoxy­propane, the aromatic rings are twisted by 35 (1)°. The heterocyclic ring exhibits a twisted conformation

    Assembly of the Lhasa and Qiangtang terranes in central Tibet by divergent double subduction

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    This research was financially co-supported by the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (XDB03010301), the National Key Project for Basic Research of China (2011CB403102 and 2015CB452604), the Chinese National Natural Science Foundation (41225006, 41472061, and 40973026), and the Specialized Research Fund for the Doctoral Program of Higher Education (20120022110001)Integration of lithostratigraphic, magmatic, and metamorphic data from the Lhasa-Qiangtang collision zone in central Tibet (including the Bangong suture zone and adjacent regions of the Lhasa and Qiangtang terranes) indicates assembly through divergent double sided subduction. This collision zone is characterized by the absence of Early Cretaceous high-grade metamorphic rocks and the presence of extensive magmatism with enhanced mantle contributions at ca. 120–110 Ma. Two Jurassic−Cretaceous magmatic arcs are identified from the Caima−Duobuza−Rongma−Kangqiong−Amdo magmatic belt in the western Qiangtang Terrane and from the Along Tso−Yanhu−Daguo−Baingoin−Daru Tso magmatic belt in the northern Lhasa Terrane. These two magmatic arcs reflect northward and southward subduction of the Bangong Ocean lithosphere, respectively. Available multidisciplinary data reconcile that the Bangong Ocean may have closed during the Late Jurassic−Early Cretaceous (most likely ca. 140–130 Ma) through arc-arc “soft” collision rather than continent-continent “hard” collision. Subduction zone retreat associated with convergence beneath the Lhasa Terrane may have driven its rifting and separation from the northern margin of Gondwana leading to its accretion within Asia.PostprintPeer reviewe

    Imaging Molecular Outflow in Massive Star-forming Regions with HNCO Lines

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    Protostellar outflows are considered a signpost of star formation. These outflows can cause shocks in the molecular gas and are typically traced by the line wings of certain molecules. HNCO (4--3) has been regarded as a shock tracer because of the high abundance in shocked regions. Here we present the first imaging results of HNCO (4--3) line wings toward nine sources in a sample of twenty three massive star-forming regions using the IRAM 30\,m telescope. We adopt the velocity range of the full width of HC3_{3}N (10--9) and H13^{13}CO+^+ (1--0) emissions as the central emission values, beyond which the emission from HNCO (4--3) is considered to be from line wings. The spatial distributions of the red- and/or blue-lobes of HNCO (4--3) emission nicely associate with those lobes of HCO+^{+} (1--0) in most of the sources. High intensity ratios of HNCO (4--3) to HCO+^+ (1--0) are obtained in the line wings. The derived column density ratios of HNCO to HCO+^+ are consistent with those previously observed towards massive star-forming regions. These results provide direct evidence that HNCO could trace outflow in massive star-forming regions. This work also implies that the formation of some HNCO molecules is related to shock, either on the grain surface or within the shocked gas.Comment: 18 pages, 4 tables, 4 figures, and accepted for publication in Ap

    Shooting method for free vibration of FGM Reissner-Mindlin circular plates resting on elastic foundation in thermal environments

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    This paper presents a free vibration analysis of functionally graded Reissner-Mindlin circular plates with various supported boundaries in thermal environments. A FGM consisting of metal and ceramic was considered in the study. Based on the geometric equation, physical equation and equilibrium equation of thick plate, taking into account the transverse shearing deformation, the free vibration equation of the axisymmetric FGM moderately thick circular plates was derived in terms of the middle surface angles of rotation and lateral displacement. The material properties of the plate were assumed to vary continuously in the thickness direction according a power law. By using shooting method to solve the coupled ordinary differential equations with different boundary conditions, the natural frequencies of FGM thick circular plates were obtained numerically. The effects of material gradient property, thickness ratio and boundary conditions on the natural frequencies were discussed in detail

    Detection of differentially expressed genes between Erhualian and Large White placentas on day 75 and 90 of gestation

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    <p>Abstract</p> <p>Background</p> <p>Placental efficiency is strongly associated with litter size, fetal weight and prenatal mortality. Together with its rapid growth during late gestation, the Large White pig breed shows a significant increase in placental size and weight, but this does not occur in the highly prolific Chinese pig breeds. To understand the molecular basis of placental development during late gestation in Chinese indigenous and Western breeds with different placental efficiency, female placental samples were collected from six pregnant Erhualian gilts at gestation day 75 (E75) and day 90 (E90) and from six pregnant Large White gilts at gestation day 75 (L75) and day 90 (L90). Two female placentas from one sow were used to extract RNA and then pooled in equal volumes. Twelve pooled samples were hybridized to the porcine Affymetrix GeneChip.</p> <p>Results</p> <p>A total of 226 and 577 transcripts were detected that were differentially expressed between E75 and L75 and between E90 and L90 (p < 0.01, q < 0.2), respectively. Gene Ontology (GO) analysis revealed that these genes belong to the class of genes that participate in angiogenesis and development. Real-time RT-PCR confirmed the differential expression of eight selected genes. Significant differential expression of five genes in the <it>VEGF </it>pathway was also detected between the breeds. A search of chromosomal location revealed that 44 differentially expressed genes located to QTL regions related to reproduction. Differential expression of six candidate imprinted genes was also confirmed. Three of the six genes (<it>PLAGL1</it>, <it>DIRAS3</it>, and <it>SLC38A4</it>) showed monoallelic expression in the porcine placenta.</p> <p>Conclusion</p> <p>Our study detected many genes that showed differential expression between placentas of two divergent breed of pigs, and confirmed the imprinting of three genes. These findings help to elucidate the genetic control of placental efficiency and improve the understanding of placental development.</p
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