2,964 research outputs found

    Precision Mass Determination of the Higgs Boson at Photon-Photon Colliders

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    We demonstrate a measurement of the Higgs boson mass by the method of energy scanning at photon-photon colliders, using the high energy edge of the photon spectrum. With an integrated luminosity of 50 fb1\rm{fb^{-1}} it is possible to measure the standard model Higgs mass to within 110 MeV in photon-photon collisions for m_h=100 GeV. As for the total width of the Higgs boson, the statistical error ΔΓh/ΓhSM=0.06\Delta\Gamma_h/\Gamma_{h \rm{SM}}=0.06 is expected for m_h=100 GeV, if both Γ(hγγ)\Gamma(h\to\gamma\gamma) and Γ(hbbˉ)\Gamma(h\to b\bar{b}) are fixed at the predicted standard model value.Comment: 7 pages, 4 figures, Given at 3nd International Workshop on Electron-Electron Interactions at TeV Energies, Dec 10-12, Santa Cruz, California, 199

    Specific heat study of spin-structural change in pyrochlore Nd2_2Mo2_2O7_7

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    By measurements of specific heat, we have investigated the magnetic field (HH) induced spin-structural change in Nd2_2Mo2_2O7_7 that shows spin-chirality-related magneto-transport phenomena. A broad peak around 2 K caused by the ordering of 2-in 2-out structure of the Nd moments at zero HH shifts to the lower temperature (TT) up to around 3 T and then to the higher TT above around 3 T with increasing HH for all the direction of HH. This is due to the crossover from antiferromagnetic to ferromagnetic arrangement between the Nd and Mo moments. While the peak TT increases monotonically above 3 T for HH//[100], another peak emerges around 0.9 K at 12 T for HH//[111], which is ascribed to the ordering of 3-in 1-out structure. For HH//[110], a spike like peak is observed at around 3 T, which is caused perhaps by some spin flip transition.Comment: 5 pages, 4 figure

    Generalized hidden symmetries and the Kerr-Sen black hole

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    We elaborate on basic properties of generalized Killing-Yano tensors which naturally extend Killing-Yano symmetry in the presence of skew-symmetric torsion. In particular, we discuss their relationship to Killing tensors and the separability of various field equations. We further demonstrate that the Kerr-Sen black hole spacetime of heterotic string theory, as well as its generalization to all dimensions, possesses a generalized closed conformal Killing-Yano 2-form with respect to a torsion identified with the 3-form occuring naturally in the theory. Such a 2-form is responsible for complete integrability of geodesic motion as well as for separability of the scalar and Dirac equations in these spacetimes.Comment: 33 pages, no figure

    Exotic mesons with hidden charm and bottom near thresholds

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    We study heavy hadron spectroscopy near heavy meson thresholds. We employ heavy pseudoscalar meson P and heavy vector meson P* as effective degrees of freedom and consider meson exchange potentials between them. All possible composite states which can be constructed from the P and P* mesons are studied up to the total angular momentum J <= 2. We consider, as exotic states, isosinglet states with exotic J^{PC} quantum numbers and isotriplet states. We solve numerically the Schr\"odinger equation with channel-couplings for each state. We found B(*)barB(*) molecule states for I^G(J^{PC}) = 1^+(1^{+-}) correspond to the masses of twin resonances Zb(10610) and Zb(10650). We predict several possible B(*)barB(*) bound and/or resonant states in other channels. On the other hand, there are no B(*)barB(*) bound and/or resonant states whose quantum numbers are exotic.Comment: 10 pages, 1 figure, to appear in the proceedings of The 5th International Workshop on Charm Physics (Charm 2012
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