9,048 research outputs found
Atmospheric neutrino flux at INO, South Pole and Pyh\"asalmi
We present the calculation of the atmospheric neutrino fluxes for the
neutrino experiments proposed at INO, South Pole and Pyh\"asalmi. Neutrino
fluxes have been obtained using ATMNC, a simulation code for cosmic ray in the
atmosphere. Even using the same primary flux model and the interaction model,
the calculated atmospheric neutrino fluxes are different for the different
sites due to the geomagnetic field. The prediction of these fluxes in the
present paper would be quite useful in the experimental analysis.Comment: 12Pages,9Fig
Ferrimagnetic spin-1/2 chain of alternating Ising and Heisenberg spins in arbitrarily oriented magnetic field
The ferrimagnetic spin-1/2 chain composed of alternating Ising and Heisenberg
spins in an arbitrarily oriented magnetic field is exactly solved using the
spin-rotation transformation and the transfer-matrix method. It is shown that
the low-temperature magnetization process depends basically on a spatial
orientation of the magnetic field. A sharp stepwise magnetization curve with a
marked intermediate plateau, which emerges for the magnetic field applied along
the easy-axis direction of the Ising spins, becomes smoother and the
intermediate plateau shrinks if the external field is tilted from the easy-axis
direction. The magnetization curve of a polycrystalline system is also
calculated by performing powder averaging of the derived magnetization formula.
The proposed spin-chain model brings an insight into high-field magnetization
data of 3d-4f bimetallic polymeric compound Dy(NO_3)(DMSO)_2Cu(opba)(DMSO)_2,
which provides an interesting experimental realization of the ferrimagnetic
chain composed of two different but regularly alternating spin-1/2 magnetic
ions Dy^{3+} and Cu^{2+} that are reasonably approximated by the notion of
Ising and Heisenberg spins, respectively.Comment: 11 pages, 6 figure
Field induced long-range-ordering in an S=1 quasi-one-dimensional Heisenberg antiferromagnet
We have measured the heat capacity and magnetization of the spin one
one-dimensional Heisenberg antiferromagnet NDMAP and constructed a magnetic
field versus temperature phase diagram. We found a field induced long-range
magnetic ordering. We have been successful in explaining the phase diagram
theoretically.Comment: 6 pages, 18 figure
Field-induced 3- and 2-dimensional freezing in a quantum spin liquid
Field-induced commensurate transverse magnetic ordering is observed in the
Haldane-gap compound \nd by means of neutron diffraction. Depending on the
direction of applied field, the high-field phase is shown to be either a
3-dimensional ordered N\'{e}el state or a short-range ordered state with
dominant 2-dimensional spin correlations. The structure of the high-field phase
is determined, and properties of the observed quantum phase transition are
discussed.Comment: 4 pages 3 figure
A simulation of high energy cosmic ray propagation 1
High energy cosmic ray propagation of the energy region 10 to the 14.5 power - 10 to the 18th power eV is simulated in the inter steller circumstances. In conclusion, the diffusion process by turbulent magnetic fields is classified into several regions by ratio of the gyro-radius and the scale of turbulence. When the ratio becomes larger then 10 to the minus 0.5 power, the analysis with the assumption of point scattering can be applied with the mean free path E sup 2. However, when the ratio is smaller than 10 to the minus 0.5 power, we need a more complicated analysis or simulation. Assuming the turbulence scale of magnetic fields of the Galaxy is 10-30pc and the mean magnetic field strength is 3 micro gauss, the energy of cosmic ray with that gyro-radius is about 10 to the 16.5 power eV
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