\begin{table}%t1
%%\centering

\par
\caption{Explanation of the different fitting parameters used for Eq.~(\ref{lifetimeequ}).}
\begin{tabular}{l l l l}
\hline\hline
Distribution type & Fit parameter & Representation & Meaning \\
\hline
lifetimes&$x(t)$& $A(t)$& Number of MBPs with a lifetime of $t$ minutes in a 1~min interval.\\
& & & Could be interpreted as ``activity'' (according to radio-activity):\\
& & & number of MBPs that decay within 1~min at time $t$.\\
& $a$& $A(0)$& Starting activity (number of MBPs which will decay within the first min)\\
&$b$&$\lambda$&Decaying parameter (related to the mean lifetime $\tau=1/\lambda$)\\
\hline
cumulated& $x(t)$& $N(t)$& Number of MBPs with a lifetime greater than $t$\\
lifetimes& $a$& $N(0)$& Number of all MBPs\\
&$b$&$\lambda$&Decaying parameter\\
\hline
\end{tabular}
\label{explife}
\end{table}