Re: [fluka-discuss]: eta(550) decays

From: Joseph Comfort <Joseph.Comfort_at_asu.edu>
Date: Wed, 02 Oct 2013 13:09:01 -0700

Hi Giuseppe,
Thank you for your quick reply. I have a problem and do not see a way
to solve it.

I am not interested in transporting etas, and they would travel
negligibly little anyway before decaying (like pi0s). But when the code
produces them and causes them to decay, it knows exactly where that
happens and what decay mode is chosen. That is the information I am
trying to find. Would that not be somewhere in the complete dump file
and, if so, how can I find it without producing a very huge complete
file? I thought that testing for Icode 102 in USDRAW might be the
point. Is there some other place?

I do not see a good reason to suppress some particles from the user.
The properties of etas are defined in bdpart.f, in ID slot 31. The
(PART) and (PART2) commons include a Parameter KPETA0 = 31. They have
been important particles for many experiments. Conceptually, all such
particles can be treated as being transported a distance zero, and skip
the transport routines.

In my case, the largest background for a K0LONG decay experiment came
from neutrons in the beam hitting collimator materials, producing etas
that decayed into 2 gammas, but the gammas being misconstrued as a pi0
by the analysis algorithm. We have made many substantial improvements
and are aiming for a factor of 1000 improvement. But very detailed
studies are needed. Even if another code can do it, I also want Fluka
results for comparison due to the uncertainties of such calculations.

I would certainly appreciate any help or code modifications so I can get
the information that I need and does exist.

Thank you,
Joe Comfort
Received on Wed Oct 02 2013 - 22:58:07 CEST