447 research outputs found
Body temperatures in two brazilian primates
O ciclo de temperatura corpórea diário do saguà Callithrix jacchus (4 o) tem uma amplitude de 4,3ºC, cêrca de 2 vêzes a observada em outros primatas e mais elevada em qualquer outro mamÃfero. O máximo foi à s 9,30 horas (39,7 mais ou menos 0,98º) e o mÃnimo foi à s 1,30 horas (35,4 mais ou menos 0,4º
Analysis of intermittency in submillimeter radio and hard x-ray data during the impulsive phase of a solar flare
We present an analysis of intermittent processes occurring during the impulsive phase of the flare SOL2012-03-13, using hard X-rays and submillimeter radio data. Intermittency is a key characteristic in turbulent plasmas and has so far only been analyzed for hard X-ray data. Since in a typical flare the same accelerated electron population is believed to produce both hard X-rays and gyrosynchrotron radiation, we compare the two time profiles by searching for intermittency signatures. For this, we define a cross-wavelet power spectrum, which is used to obtain the local intermittency measure, or LIMLIM. When greater than three, the square LIMLIM coefficients indicate a local intermittent process. The LIM2LIM2 coefficient distribution in time and scale helps to identify avalanche or cascade energy release processes. We find two different and well-separated intermittent behaviors in the submillimeter data: for scales greater than 20Â s, a broad distribution during the rising and maximum phases of the emission seems to favor a cascade process; for scales below 1Â s, short pulses centered on the peak time are representative of avalanches. When applying the same analysis to hard X-rays, we find that only the scales above 10Â s produce a distribution related to a cascade energy fragmentation. Our results suggest that different acceleration mechanisms are responsible for tens of keV and MeV energy ranges of electrons
Dirac and Majorana heavy neutrinos at LEP II
The possibility of detecting single heavy Dirac and Majorana neutrinos at LEP
II is investigated for heavy neutrino masses in the range . We study the process as a clear signature for heavy neutrinos. Numerical estimates for
cross sections and distributions for the signal and the background are
calculated and a Monte Carlo reconstruction of final state particles after
hadronization is presented.Comment: 4 pages, 8 figure
Neutral heavy lepton production at next high energy linear colliders
The discovery potential for detecting new heavy Majorana and Dirac neutrinos
at some recently proposed high energy colliders is discussed. These
new particles are suggested by grand unified theories and superstring-inspired
models. For these models the production of a single heavy neutrino is shown to
be more relevant than pair production when comparing cross sections and
neutrino mass ranges.
The process is calculated
including on-shell and off-shell heavy neutrino effects.
We present a detailed study of cross sections and distributions that shows a
clear separation between the signal and standard model contributions, even
after including hadronization effects.Comment: 4 pages including 15 figures, 1 table. RevTex. Accepted in Physical
Review
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