3,704 research outputs found
A proposal for a different chi-square function for Poisson distributions
We obtain an approximate Gaussian distribution from a Poisson distribution
after doing a change of variable. A new chi-square function is obtained which
can be used for parameter estimations and goodness-of-fit testing when
adjusting curves to histograms. Since the new distribution is approximately
Gaussian we can use it even when the bin contents are small. The corresponding
chi-square function can be used for curve fitting. This chi-square function is
simple to implement and presents a fast convergence of the parameters to the
correct value, especially for the parameters associated with the width of the
fitted curve. We present a Monte Carlo comparative study of the fitting method
introduced here and two other methods for three types of curves: Gaussian,
Breit-Wigner and Moyal, when each bin content obeys a Poisson distribution. It
is also shown that the new method and the other two converge to the same result
when the number of events increasesComment: 27 pages, 13 figure
Aprendendo com a natureza.
bitstream/item/94348/1/Midia-Aprendendo-com-a-natureza-Portal-Dia-de-Campo.pd
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
Rhizobacteria promoting growth and defense in rice plants against Magnaporthe oryzae.
This study investigated the effect of PGPR in promoting growth of rice roots and suppressing leaf blast (Magnaporthe oryzae)
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