2,964 research outputs found

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

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 $\rm{fb^{-1}}$ 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 $\Delta\Gamma_h/\Gamma_{h \rm{SM}}=0.06$ is expected for
m_h=100 GeV, if both $\Gamma(h\to\gamma\gamma)$ and $\Gamma(h\to b\bar{b})$ 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 Nd$_2$Mo$_2$O$_7$

By measurements of specific heat, we have investigated the magnetic field
($H$) induced spin-structural change in Nd$_2$Mo$_2$O$_7$ 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 $H$
shifts to the lower temperature ($T$) up to around 3 T and then to the higher
$T$ above around 3 T with increasing $H$ for all the direction of $H$. This is
due to the crossover from antiferromagnetic to ferromagnetic arrangement
between the Nd and Mo moments. While the peak $T$ increases monotonically above
3 T for $H$//[100], another peak emerges around 0.9 K at 12 T for $H$//[111],
which is ascribed to the ordering of 3-in 1-out structure. For $H$//[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

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

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

- â€¦