tau                   package:boot                   R Documentation

Tau Particle Decay Modes

Description:

     The 'tau' data frame has 60 rows and 2 columns.

     The tau particle is a heavy electron-like particle discovered in
     the 1970's by Martin Perl at the Stanford Linear Accelerator
     Center.  Soon after its production the tau particle decays into
     various collections of more stable particles.  About 86% of the
     time the decay involves just one charged particle. This rate has
     been measured independently 13 times.  

     The one-charged-particle event is made up of four major modes of
     decay as well as a collection of other events.  The four main
     types of decay are denoted rho, pi, e and mu.  These rates have
     been measured independently 6, 7, 14 and 19 times respectively. 
     Due to physical constraints each experiment can only estimate the
     composite one-charged-particle decay rate or the rate of one of
     the major modes of decay.  

     Each experiment consists of a major research project involving
     many years work. One of the goals of the experiments was to
     estimate the rate of decay due to  events other than the four main
     modes of decay.  These are uncertain events and so cannot
     themselves be observed directly.

Usage:

     tau

Format:

     This data frame contains the following columns:


     'rate' The decay rate expressed as a percentage.

     'decay' The type of decay measured in the experiment.  It is a
          factor with levels '1', 'rho', 'pi', 'e' and 'mu'.

Source:

     The data were obtained from

     Efron, B. (1992) Jackknife-after-bootstrap standard errors and
     influence  functions (with Discussion).  _Journal of the Royal
     Statistical Society, B_, *54*, 83-127.

References:

     Davison, A.C. and Hinkley, D.V. (1997)  _Bootstrap Methods and
     Their Application_. Cambridge University Press.

     Hayes, K.G., Perl, M.L. and Efron, B. (1989) Application of the
     bootstrap statistical method to the tau-decay-mode problem. 
     _Physical Review, D_, *39*, 274-279.

