

   TTaauu PPaarrttiiccllee DDeeccaayy MMooddeess

   AArrgguummeennttss::

       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'.

   SSUUMMMMAARRYY::

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

        The tau particle is a heavy electron-like particle dis-
        covered 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 con-
        straints each experiment can only estimate the compos-
        ite 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.

   DDAATTAA DDEESSCCRRIIPPTTIIOONN::

        This data frame contains the following columns:

   SSOOUURRCCEE::

        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.

   OOTTHHEERR RREEFFEERREENNCCEESS::

        Davison, A.C. and Hinkley, D.V. (1997) Bootstrap Meth-
        ods and Their Application. Cambridge University Press.

        Hayes, K.G., Perl, M.L. and Efron, B. (1989) Applica-
        tion of the bootstrap statistical method to the tau-
        decay-mode problem.  Physical Review, D, 39, 274-279.

