65,452 research outputs found

    Pure spinor computation towards open string three-loop

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    Using the recent results in the pure spinor formulation, we lay out a ground-work towards the full momentum space amplitudes of open superstrings at three-loop. After briefly reviewing the one-loop amplitude, we directly work out the two-loop and reproduce the result that was obtained by a symmetry argument. For the three-loop, first we use the two-loop regulator as a warm-up exercise. The result vanishes. We then employ the regulator that has been recently proposed by Aisaka and Berkovits (AB). It is noted that the terms in higher power in 1λλˉ\frac{1}{\lambda\bar{\lambda}} that render the two-loop regulator disqualified for the three-loop do not contribute. This with a few other indications suggests a possibility that the AB regulator might also lead to a vanishing result. Nevertheless, we argue that it is possible to acquire the three-loop amplitude, and present a result that we anticipate to be the three-loop amplitude.Comment: 41 pages, latex, cosmetic change

    Massive super Yang-Mills quantum mechanics: classification and the relation to supermembrane

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    We classify the supersymmetric mass deformations of all the super Yang-Mills quantum mechanics, which are obtained by dimensional reductions of minimal super Yang-Mills in spacetime dimensions: ten, six, four, three and two. The resulting actions can be viewed as the matrix descriptions of supermembranes in nontrivial backgrounds of one higher dimensional supergravity theories. We also discuss the utmost generalization of the light-cone formulation of the Nambu-Goto action for a p-brane, including time dependent backgrounds

    Limits on Interactions between Weakly Interacting Massive Particles and Nucleons Obtained with NaI(Tl) crystal Detectors

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    Limits on the cross section for weakly interacting massive particles (WIMPs) scattering off nucleons in the NaI(Tl) detectors at the Yangyang Underground Laboratory are obtained with a 2967.4 kg*day data exposure. Nuclei recoiling are identified by the pulse shape of scintillating photon signals. Data are consistent with no nuclear recoil hypothesis, and 90% confidence level upper limits are set. These limits partially exclude the DAMA/LIBRA region of WIMP-sodium interaction with the same NaI(Tl) target detector. This 90% confidence level upper limit on WIMP-nucleon spin-independent cross section is 3.26*10^-4 pb for a WIMP mass at 10 GeV/c^2
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