Q2: Decay mode identification number.

First of all, read the file, $(KFLIBROOT)/README. There are valuable information there.

In Physsim generator, each decay mode of W and Zhas decay mode ID as shown in the Table 1.

 

Table 1:W and Z decay mode and their ID number used in Physsim generator.

ID number	Z decay	W decay
1	$\nu_\ell \bar{\nu_\ell}$	$\ell \nu_\ell$
2	$\nu_\mu \bar{\nu_\mu}$	$mu \nu_\mu$
3	$\nu_\tau \bar{\nu_\tau}$	$\tau \nu_\tau$
4	$\ell\bar{\ell}$	$d\bar{u}$
5	$\mu\bar{\mu}$	$d\bar{c}$
6	$\tau\bar{\tau}$	$d\bar{t}$ (forbidden)
7	$u\bar{u}$	$s\bar{u}$
8	$c\bar{c}$	$s\bar{c}$
9	$t\bar{t}$ (forbidden)	$s\bar{t}$ (forbidden)
10	$d\bar{d}$	$b\bar{u}$
11	$s\bar{s}$	$b\bar{c}$
12	$b\bar{b}$	$b\bar{t}$ (forbidden)