561 research outputs found

    Quark Coulomb Interactions and the Mass Difference of Mirror Nuclei

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    We study the Okamoto-Nolen-Schiffer (ONS) anomaly in the binding energy of mirror nuclei at high density by adding a single neutron or proton to a quark gluon plasma. In this high-density limit we find an anomaly equal to two-thirds of the Coulomb exchange energy of a proton. This effect is dominated by quark electromagnetic interactions---rather than by the up-down quark mass difference. At normal density we calculate the Coulomb energy of neutron matter using a string-flip quark model. We find a nonzero Coulomb energy because of the neutron's charged constituents. This effect could make a significant contribution to the ONS anomaly.Comment: 4 pages, 2 figs. sub. to Phys. Rev. Let

    bsb \to s Transitions in Family-dependent U(1)U(1)^\prime Models

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    We analyze flavor-changing-neutral-current (FCNC) effects in the bsb\to s transitions that are induced by family non-universal U(1)U(1)' gauge symmetries. After systematically developing the necessary formalism, we present a correlated analysis for the ΔB=1,2\Delta B =1, 2 processes. We adopt a model-independent approach in which we only require family-universal charges for the first and second generations and small fermion mixing angles. We analyze the constraints on the resulting parameter space from BsBˉsB_s - \bar B_s mixing and the time-dependent CP asymmetries of the penguin-dominated Bd(π,ϕ,η,ρ,ω,f0)KSB_d \to (\pi, \phi, \eta', \rho, \omega, f_0)K_S decays. Our results indicate that the currently observed discrepancies in some of these modes with respect to the Standard Model predictions can be consistently accommodated within this general class of models.Comment: 36 pages, 11 figure

    Generic flow profiles induced by a beating cilium

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    We describe a multipole expansion for the low Reynolds number fluid flows generated by a localized source embedded in a plane with a no-slip boundary condition. It contains 3 independent terms that fall quadratically with the distance and 6 terms that fall with the third power. Within this framework we discuss the flows induced by a beating cilium described in different ways: a small particle circling on an elliptical trajectory, a thin rod and a general ciliary beating pattern. We identify the flow modes present based on the symmetry properties of the ciliary beat.Comment: 12 pages, 6 figures, to appear in EPJ

    Critical Correlations of Wilson Lines in SU(3) and the High Energy γp\gamma^*p Cross Section

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    We discuss deep inelastic scattering at high energies as a critical phenomenon in 2+1 space - time dimensions. In the limit of Bjorken x0x \to 0, QCDQCD SU(3) with quark fields becomes a critical theory with a diverging correlation length ξ(x)x12λ2\xi(x) \propto x^{-\frac{1}{2 \lambda_2}} where the exponent λ2=2.52\lambda_2=2.52 is obtained from the center group Z(3) of SU(3). We conjecture that the dipole wave function of the virtual photon for transverse sizes 1/Q<x<ξ1/Q<x_{\bot}<\xi obeys correlation scaling Ψ(x)(1+n)\Psi \propto (x_{\bot})^{-(1+n)} before exponentially decaying for distances larger than the correlation length. Using this behavior combined with different xx -independent dipole proton cross sections we calculate the proton structure function and compare with the experimental data. We take the good agreement with the measured proton structure function F2(x,Q2)_2(x,Q^2) as an indication that at high energies dimensional reduction to an effective three dimensional theory with a critical point occurs.Comment: 21 pages, 3 figure

    Óleo essencial de alecrim no controle de doenças e na indução de resistência em videira

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    O objetivo deste trabalho foi determinar as características químicas do óleo essencial de alecrim e o seu efeito na produtividade, no controle da mancha da folha e do míldio, e na indução de resistência em videira 'Isabel'. O experimento foi realizado em vinhedo comercial, em dois ciclos consecutivos. Os tratamentos consistiram das doses do óleo essencial: 0, 500, 1.000, 2.000 e 4.000 µL L-1, além dos tratamentos Tween 80%, calda bordalesa, acibenzolar-S-metil e mancozebe. Foram avaliados a severidade da mancha da folha e do míldio, a atividade das enzimas quitinase e catalase, a massa e o número de cachos e as características químicas das uvas. Houve efeito quadrático das doses do óleo essencial de alecrim, para severidade da mancha da folha e do míldio da videira, nos dois ciclos, com resultados semelhantes aos dos tratamentos com calda bordalesa, acibenzolar-S-metil e mancozeb. Também houve aumento no número e na massa dos cachos, bem como na produtividade. O óleo essencial não interferiu nas características químicas das uvas. Observaram-se aumento na atividade da enzima quitinase e redução na atividade da catalase nas folhas. O óleo essencial nas doses de 500, 1.000 e 2.000 μL L-1 é uma alternativa para o controle de doenças da videira 'Isabel'

    Measurement of the cross section for isolated-photon plus jet production in pp collisions at √s=13 TeV using the ATLAS detector

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    The dynamics of isolated-photon production in association with a jet in proton–proton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fb−1. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti- algorithm with radius parameter and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photon–jet invariant mass and the scattering angle in the photon–jet centre-of-mass system. Tree-level plus parton-shower predictions from Sherpa and Pythia as well as next-to-leading-order QCD predictions from Jetphox and Sherpa are compared to the measurements

    A search for resonances decaying into a Higgs boson and a new particle X in the XH → qqbb final state with the ATLAS detector

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    A search for heavy resonances decaying into a Higgs boson (H) and a new particle (X) is reported, utilizing 36.1 fb−1 of proton–proton collision data at collected during 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. The particle X is assumed to decay to a pair of light quarks, and the fully hadronic final state is analysed. The search considers the regime of high XH resonance masses, where the X and H bosons are both highly Lorentz-boosted and are each reconstructed using a single jet with large radius parameter. A two-dimensional phase space of XH mass versus X mass is scanned for evidence of a signal, over a range of XH resonance mass values between 1 TeV and 4 TeV, and for X particles with masses from 50 GeV to 1000 GeV. All search results are consistent with the expectations for the background due to Standard Model processes, and 95% CL upper limits are set, as a function of XH and X masses, on the production cross-section of the resonance
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