5,236 research outputs found

    Searches for High Mass Resonances and Exotics at the Tevatron

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    I review recent searches for physics beyond the standard model from the CDF and D0 experiments at the Fermilab Tevatron collider, covering searches for fourth generation quarks, exotic resonances, universal extra dimensions, and dark matter particles.Comment: Presented at the 2011 Hadron Collider Physics symposium (HCP-2011), Paris, France, November 14-18 2011, 4 pages, 12 figure

    Precision Measurements of the W-Boson Mass

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    The Standard Model of electroweak interactions has had great success in describing the observed data over the last three decades. The precision of experimental measurements affords tests of the Standard Model at the quantum loop level beyond leading order. Despite this great success it is important to continue confronting experimental measurements with the Standard Model predictions as any deviation would signal new physics. As a fundamental parameter of the Standard Model, the mass of the W-boson, M_W, is of particular importance. Aside from being an important test of the SM itself, a precision measurement of M_W can be used to constrain the mass of the Higgs boson, M_H. In this article we review the principal experimental techniques for determining M_W and discuss their combination into a single precision M_W measurement, which is then used to yield constraints on M_H. We conclude by briefly discussing future prospects for precision measurements of the W-boson mass.Comment: 37 pages, 13 figures, LaTex, to be published in volume 50 of Annual Review of Nuclear and Particle Scienc

    Efficient evaluation of specific queries in constraint databases

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    Let F1,...,FsεR[X1,...,Xn] be polynomials of degree at most d, and suppose that F1,...,F s are represented by a division free arithmetic circuit of non-scalar complexity size L. Let A be the arrangement of Rn defined by F 1,...,Fs. For any point xεRn, we consider the task of determining the signs of the values F1(x),...,F s(x) (sign condition query) and the task of determining the connected component of A to which x belongs (point location query). By an extremely simple reduction to the well-known case where the polynomials F 1,...,Fs are affine linear (i.e., polynomials of degree one), we show first that there exists a database of (possibly enormous) size sO(L+n) which allows the evaluation of the sign condition query using only (Ln)O(1)log(s) arithmetic operations. The key point of this paper is the proof that this upper bound is almost optimal. By the way, we show that the point location query can be evaluated using dO(n)log(s) arithmetic operations. Based on a different argument, analogous complexity upper-bounds are exhibited with respect to the bit-model in case that F 1,...,Fs belong to Z[X1,...,Xn] and satisfy a certain natural genericity condition. Mutatis mutandis our upper-bound results may be applied to the sparse and dense representations of F 1,...,Fs.Fil: Grimson, Rafael. Hasselt University; Bélgica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; ArgentinaFil: Heintz, Joos Ulrich. Universidad de Cantabria; España. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Computación; ArgentinaFil: Kuijpers, Bart. Hasselt University; Bélgic
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