55,885 research outputs found

    Real photons produced from photoproduction in pppp collisions

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    We calculate the production of real photons originating from the photoproduction in relativistic pppp collisions. The Weizsa¨\ddot{\mathrm{a}}cker-Williams approximation in the photoproduction is considered. Numerical results agree with the experimental data from Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC). We find that the modification of the photoproduction is more prominent in large transverse momentum region.Comment: 2 figure

    A Distributive Lattice Connected with Arithmetic Progressions of Length Three

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    Let T\mathcal{T} be a collection of 3-element subsets SS of {1,,n}\{1, \ldots,n\} with the property that if i<j<ki<j<k and a<b<ca<b<c are two 3-element subsets in SS, then there exists an integer sequence x1<x2<<xnx_1 < x_2 < \cdots < x_n such that xi,xj,xkx_i, x_j, x_k and xa,xb,xcx_a, x_b, x_c are arithmetic progressions. We determine the number of such collections T\mathcal{T} and the number of them of maximum size. These results confirm two conjectures of Noam Elkies.Comment: 25 pages, 1 figure. To appear in the Ramanujan Journa

    The Lecture Hall Parallelepiped

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    The s-lecture hall polytopes P_s are a class of integer polytopes defined by Savage and Schuster which are closely related to the lecture hall partitions of Eriksson and Bousquet-M\'elou. We define a half-open parallelopiped Par_s associated with P_s and give a simple description of its integer points. We use this description to recover earlier results of Savage et al. on the \delta-vector (or h^*-vector) and to obtain the connections to s-ascents and s-descents, as well as some generalizations of these results.Comment: 14 pages. To appear in Annals of Combinatoric

    Guanxi and the organization of Chinese new year festivals in England

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    This article explores how Chinese diaspora communities use guanxi, a unique Chinese interpretation of personal relationships, in the organization of Chinese New Year (CNY) festivals in England. A case-study approach that incorporated mixed qualitative methods was used to investigate the interactions and interrelationships between the ethnic Chinese communities involved in the organization of CNY festivals in five English cities. The article argues that Chinese diaspora communities use their guanxi to establish collaboration at CNY festivals. However, the process of organizing CNY festivals has also exposed divisions among Chinese communities. The article proposes that guanxi has important implications for the relationships among Chinese diaspora communities in the context of CNY festivals. Although it facilitates collaboration and promotes solidarity among Chinese communities, it may also intensify competition for power. Diaspora festivals in general are a neglected area of research and this article is the first to study the organization of Chinese New Year festivals in detail

    Graphene oxide-Au nano particle coated quartz crystal microbalance biosensor for the real time analysis of carcinoembryonic antigen

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    A label-free quartz crystal microbalance (QCM) biosensor was developed for the selective and real-time estimation of carcinoembryonic antigen (CEA) through the present study. Graphene oxide-Au nanoparticles (GO-AuNPs) was in situ synthesised on the surface of the QCM electrode and the antibody of CEA (monoclonal anti-CEA from mouse) was covalently immobilized on this layer as the bioreceptor for CEA. Mercaptoacetic acid–EDC–NHS reaction mechanism was used for anti-CEA immobilization. The effect of oxygen plasma treatment of the QCM electrode surface before bioreceptor preparation on the performance of the biosensor was tested and was found promising. CEA solutions with various concentrations were analysed using the bioreceptors to estimate the sensitivity and detection limit of the biosensor. The biosensors selectively recognized and captured CEA biomolecules with a detection limit of 0.06 and 0.09 ng mL−1 of CEA for oxygen plasma-treated (E2) and untreated (E1) bioreceptors, respectively. The sensitivity was estimated at 102 and 79 Hz, respectively, for E2 and E1. Clinical serum samples were analysed and the results were found in good agreement with the ELISA analysis. Long term stability was also found to be excellent. Langmuir adsorption isotherm was also conducted using the experimental results

    Interaction induced mergence of Dirac points in Non-Abelian optical lattices

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    We study the properties of an ultracold Fermi gas loaded in a square optical lattice and subjected to an external and classical non-Abelian gauge field. We calculate the energy spectrum of the system and show that the Dirac points in the energy spectrum will remain quite stable under onsite interaction of certain strength. Once the on-site interaction grows stronger than a critical value, the Dirac points will no longer be stable and merge into a single hybrid point. This mergence implies a quantum phase transition from a semimetallic phase to a band insulator. The on-site interaction between ultracold fermions could be conveniently controlled by Feshbach resonances in current experiments. We proposed that this remarkable interaction induced mergence of Dirac points may be observed in the ultracold fermi gas experiments
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