4,227 research outputs found
Two monotonic functions involving gamma function and volume of unit ball
In present paper, we prove the monotonicity of two functions involving the
gamma function and relating to the -dimensional volume of the
unit ball in .Comment: 7 page
A cosmic ray super high multicore family event. 1: Experiment and general features
Information on the fragmentation region in super high energy hadronic interactions can be obtained through the observations of gamma-ray families produced by cosmic rays. Gamma-ray families with the sum of E sub gamma or 1000 TeV are receiving increasing interests in emulsion chamber experiments. There exist some complications caused by the superposition of nuclear and electromagnetic cascades and the uncertainty in the nature of the primary particles. These complications usually make the conclusions drawn from various interesting phenomena observed in family events not so definite. An interesting family event KO E19, which is likely to have suffered only very slight disturbances is described. It was found in the Mt. Kambala emulsion chamber experiment. The production height of the event is determined to be H=(70 + or - 30)m and some conclusions are given
Intensities of high-energy cosmic rays at Mount Kanbala
The energy spectra of atmospheric cosmic rays at Mt. Kanbala (520 g/sq cm.) are measured with emulsion chambers. The power indexes of the spectra are values of about 2.0 for both gamma-rays and hadrons. Those fluxes are consistent with the ones expected from the model of primary cosmic rays with heavy nuclei of high content in the energy around 10 to the 15th power eV
Pseudospectral Calculation of the Wavefunction of Helium and the Negative Hydrogen Ion
We study the numerical solution of the non-relativistic Schr\"{o}dinger
equation for two-electron atoms in ground and excited S-states using
pseudospectral (PS) methods of calculation. The calculation achieves
convergence rates for the energy, Cauchy error in the wavefunction, and
variance in local energy that are exponentially fast for all practical
purposes. The method requires three separate subdomains to handle the
wavefunction's cusp-like behavior near the two-particle coalescences. The use
of three subdomains is essential to maintaining exponential convergence. A
comparison of several different treatments of the cusps and the semi-infinite
domain suggest that the simplest prescription is sufficient. For many purposes
it proves unnecessary to handle the logarithmic behavior near the
three-particle coalescence in a special way. The PS method has many virtues: no
explicit assumptions need be made about the asymptotic behavior of the
wavefunction near cusps or at large distances, the local energy is exactly
equal to the calculated global energy at all collocation points, local errors
go down everywhere with increasing resolution, the effective basis using
Chebyshev polynomials is complete and simple, and the method is easily
extensible to other bound states. This study serves as a proof-of-principle of
the method for more general two- and possibly three-electron applications.Comment: 23 pages, 20 figures, 2 tables, Final refereed version - Some
references added, some stylistic changes, added paragraph to matrix methods
section, added last sentence to abstract
The Superluminal Neutrinos from Deformed Lorentz Invariance
We study two superluminal neutrino scenarios where \delta v\equiv (v-c)/c is
a constant. To be consistent with the OPERA, Borexino, and ICARUS experiments
and with the SN1987a observations, we assume that \delta v_{\nu} on the Earth
is about three order larger than that on the interstellar scale. To explain the
theoretical challenges from the Bremsstrahlung effects and pion decays, we
consider the deformed Lorentz invariance, and show that the superluminal
neutrino dispersion relations can be realized properly while the modifications
to the dispersion relations of the other Standard Model particles can be
negligible. In addition, we propose the deformed energy and momentum
conservation laws for a generic physical process. In Scenario I the momentum
conservation law is preserved while the energy conservation law is deformed. In
Scenario II the energy conservation law is preserved while the momentum
conservation law is deformed. We present the energy and momentum conservation
laws in terms of neutrino momentum in Scenario I and in terms of neutrino
energy in Scenario II. In such formats, the energy and momentum conservation
laws are exactly the same as those in the traditional quantum field theory with
Lorentz symmetry. Thus, all the above theoretical challenges can be
automatically solved. We show explicitly that the Bremsstrahlung processes are
forbidden and there is no problem for pion decays.Comment: RevTex4, 5 pages, comments and references adde
An investigation of clinical and immunological events following repeated aerodigestive tract challenge infections with live Mycobacterium bovis Bacille Calmette Guerin
Bacille Calmette Guérin substrain Moreau Rio de Janeiro is an attenuated strain of Mycobacterium bovis that has been used extensively as an oral tuberculosis vaccine. We assessed its potential as a challenge model to study clinical and immunological events following repeated mycobacterial gut infection. Seven individuals received three oral challenges with approximately 107 viable bacilli. Clinical symptoms, T-cell responses and gene expression patterns in peripheral blood were monitored. Clinical symptoms were relatively mild and declined following each oral challenge. Delayed T-cell responses were observed, and limited differential gene expression detected by microarrays. Oral challenge with BCG Moreau Rio de Janeiro vaccine was immunogenic in healthy volunteers, limiting its potential to explore clinical innate immune responses, but with low reactogenicity
Off-Diagonal Long Range Order and Scaling in a Disordered Quantum Hall System
We have numerically studied the bosonic off-diagonal long range order,
introduced by Read to describe the ordering in ideal quantum Hall states, for
noninteracting electrons in random potentials confined to the lowest Landau
level. We find that it also describes the ordering in disordered quantum Hall
states: the proposed order parameter vanishes in the disordered
() phase and increases continuously from zero in the ordered
() phase. We study the scaling of the order parameter and
find that it is consistent with that of the one-electron Green's function.Comment: 10 pages and 4 figures, Revtex v3.0, UIUC preprint P-94-03-02
Scaling Properties of Conductance at Integer Quantum Hall Plateau Transitions
We investigate the scaling properties of zero temperature conductances at
integer quantum Hall plateau transitions in the lowest Landau band of a
two-dimensional tight-binding model. Scaling is obeyed for all energy and
system sizes with critical exponent nu =7/3 . The arithmetic average of the
conductance at the localization-delocalization critical point is found to be
_c = 0.506 e^2 / h, in agreement with the universal longitudinal conductance
predicted by an analytical theory. The probability distribution of the
conductance at the critical point is broad with a dip at small G.Comment: 4 pages, 3 postscript figures, Submitted to PR
in Littlest Higgs Model
The inclusive process is studied in the littlest Higgs
model. The contributions arising from new particles are normally suppressed by
a factor of . Due to the large uncertainties of experimental
measurements and theoretical predictions, the model parameters can escape from
the constraints of present experiments provided TeV.Comment: 7 pages, 1 fi
Preliminary genetic evidence of two different populations of Opisthorchis viverrini in Lao PDR
Opisthorchis viverrini is a major public health concern in Southeast Asia. Various reports have suggested that this parasite may represent a species complex, with genetic structure in the region perhaps being dictated by geographical factors and different species of intermediate hosts. We used four microsatellite loci to analyze O. viverrini adult worms originating from six species of cyprinid fish in Thailand and Lao PDR. Two distinct O. viverrini populations were observed. In Ban Phai, Thailand, only one subgroup occurred, hosted by two different fish species. Both subgroups occurred in fish from That Luang, Lao PDR, but were represented to very different degrees among the fish hosts there. Our data suggest that, although geographical separation is more important than fish host specificity in influencing genetic structure, it is possible that two species of Opisthorchis, with little interbreeding, are present near Vientiane in Lao PDR
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