4,204 research outputs found

    Resummation of High Order Corrections in ZZ Boson Plus Jet Production at the LHC

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    We study the multiple soft gluon radiation effects in ZZ boson plus jet production at the LHC. By applying the transverse momentum dependent factorization formalism, the large logarithms introduced by the small total transverse momentum of the ZZ boson plus jet final state system, are resummed to all orders in the expansion of the strong interaction coupling at the accuracy of Next-to-Leading Logarithm(NLL). We also compare the prediction of our resummation calculation to the CMS data by employing a reweighting procedure to estimate the effect from imposing kinematic cuts on the leptons from ZZ boson decay, and find good agreement for both the imbalance transverse momentum and the azimuthal angle correlation of the final state ZZ boson and jet system, for ppZ+jetpp\to Z+jet production at the LHC.Comment: 7 pages, published versio

    Tetra­aqua­bis{2-[4-(3-pyrid­yl)pyrimidin-2-ylsulfan­yl]acetato}manganese(II) dihydrate

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    In the title compound, [Mn(C11H8N3O2S)2(H2O)4]·2H2O, the MnII ion lies on an inversion centre and is coordinated by four water mol­ecules in equatorial positions and two N atoms from two 2-[4-(3-pyrid­yl)pyrimidin-2-ylsulfan­yl]acetate ligands in the axial positions. The water mol­ecules, including the uncoordinated water mol­ecules, and the acetate O atoms are involved in O—H⋯O and O—H⋯N hydrogen-bonding inter­actions, which link the components into layers parallel to the a (b + c) plane

    Soft Gluon Resummation in tt-channel single top quark production at the LHC

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    We present a detailed phenomenological study of the multiple soft gluon radiation for the tt-channel single top and anti-top quark production at the Large Hadron Collider (LHC). By applying the transverse momentum dependent factorization formalism, large logarithms introduced by small total transverse momentum qq_\perp of the single-top (anti-top) plus one-jet final state system are resummed to all orders in the expansion of the strong interaction coupling at the accuracy of Next-to-Leading Logarithm. We discuss various kinematical distributions which are sensitive to this effect and find that soft gluon radiation become more important when the final state jet is required to be in the forward region. We show that the main difference from PYTHIA prediction lies on the inclusion of the exact color coherence effect between the initial and final states in our resummation calculation. We further propose to apply the experimental observable ϕ\phi^* to test the effect of multiple gluon radiation in the single-top and anti-top events. The bottom quark mass effect and jet rapidity distribution are also discussed.Comment: 22 pages. arXiv admin note: substantial text overlap with arXiv:1801.09656, arXiv:1811.0142

    Comparative analysis of the pattern of population genetic diversity in three Indo-West Pacific Rhizophora mangrove species

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    Rhizophora species are the most widely distributed mangrove trees in the Indo-West Pacific (IWP) region. Comparative studies of these species with shared life history traits can help identify evolutionary factors that have played most important roles in determining genetic diversity within and between populations in ocean-current dispersed mangrove tree species. We sampled 935 individuals from 54 natural populations for genotyping with 13 microsatellite markers to investigate the level of genetic variation, population structure, and gene flow on a broad geographic scale in Rhizophora apiculata, Rhizophora mucronata, and Rhizophora stylosa across the IWP region. In contrast to the pattern expected of long-lived woody plants with predominant wind-pollination, water-dispersed seeds and wide geographic range, genetic variation within populations was generally low in all the three species, especially in those peripheral populations from geographic range limits. Although the large water-buoyant propagules of Rhizophora have capacity for long distance dispersal, such events might be rare in reality, as reflected by the low level of gene flow and high genetic differentiation between most of population pairs within each species. Phylogeographic separation of Australian and Pacific island populations from SE Asian lineages previously revealed with DNA sequence data was still detectable in R. apiculata based on genetic distances, but this pattern of disjunction was not always evident in R. mucronata and R. stylosa, suggesting that fast-evolving molecular markers could be more suitable for detecting contemporary genetic structure but not deep evolutionary divergence caused by historical vicariance. Given that mangrove species generally have small effective population sizes, we conclude that genetic drift coupled with limited gene flow have played a dominant role in producing the current pattern of population genetic diversity in the IWP Rhizophora species, overshadowing the effects of their life history traits. Recent population fragmentation and disturbances arising from human activities could further endanger genetic diversity in mangrove trees

    QCD corrections to the R-parity violating processes ppˉ/ppeμ+Xp\bar{p}/pp \to e\mu+X at hadron colliders

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    We present the QCD corrections to the processes ppˉ/ppeμ+Xp\bar{p}/pp \to e\mu+X at the Tevatron and the CERN large hadron collider(LHC). The numerical results show that variation of K factor is in the range between 1.28(1.32)1.28(1.32) and 1.79(1.58)1.79(1.58) at the Tevatron(LHC). We find that the QCD correction part from the one-loop gluon-gluon fusion subprocess is remarkable at the LHC and should be taken into account.Comment: 7 pages, 6 Postscript figures, to be appeared in Phy. Rev.
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