Date: Tue, 28 Mar 2000 12:13:23 -0600 (CST)
From: Deborah Harris <debbie@tamora.fnal.gov>
Subject: corrections for text in section 3:
To: sgeer@fnal.gov
Reply-to: Deborah Harris <debbie@tamora.fnal.gov>
Message-id: <Pine.LNX.3.96.1000328112213.14485B-100000@tamora.fnal.gov>
MIME-version: 1.0
Content-type: TEXT/PLAIN; charset=US-ASCII

Hi Steve, 

     I thought I would explain some of the harder to understand comments 
before giving you my marked-up page.  

Page 17: The sentence I deleted seemed redundant with the following
sentence.  

"hard look" sounds too informal, I would say something more like 
"it is important to understand how our community can..." 

>> done

I would have the last sentence(s) of the first paragraph be 
something like 

"In this section we describe the theoretical basis for 
neutrino oscillations, followed by the current experimental status and how
it can be expected to change in the near future, and then complete
the section with a survey of detector technologies and how they have 
been predicted to perform in future neutrino factory experiments.  
It is clear from these studies that a muon storage ring will go well 
beyond the capabilities of the next generation of neutrino oscillation
experiments. " 

>> The appropriate paragraph has been changed, something along these lines.

On page 19:  You could introduce the jarlscog invariant here, 
and state that to see CP violating effects you must be at an 
L where the SMALLER mass difference isn't washed out. the Larger
mass difference is washed out, but it's a sin^2 term so it doesn't
matter.  

>> More complicated to introduce it (them) for >3 flavors, so prefer
>> to introduce it explicitly in context of 3 flavors.
  
There's a sin^2(larger mass difference)*sin(smaller mass difference) 
which is not clear from this discussion...

>> note sure about this comment. If its still a problem in draft 2
>> please get back to us.

page 20: mention that this is for the case where the largest mass 
difference is described by the atmospheric, so LSND is assumed false.  

>> done

(page 22) Mention that if LSND is true, other physics topics get much more 
important, but matter effects could only be seen if one either 
goes to much longer (i.e. non-terrestrial) distances or much higher 
energies (i.e. muon collider energies, not storage ring energies).  

>> footnote added

also, you should mention that the matter effects you quote are for 
neutrinos, and that there's a +- sign on A for nu/nubar, right? 

>> done

typo on page 21:  tan2theta13_m should reduce to tan2theta13_vacuum 
if A=0

>> done

page 26: discard should be discarded 

>> done

figure 14: I am 90% confident that the plot there has nu_mu to nu_tau 
limits for MINOS and K2K, not nu_mu to nu_e like it says in the text. 

>> Response from HM is that it is correct as stands. 

page 31:  the only thing you can safely say about nu_e to nu_tau is 
that NO EXPERIMENT has any hope of seeing this period in the 
near term future.  Period!  Even if you saw 100 nu_mu to nu_tau 
events at an experiment (which is way beyond what anyone will see) 
remember the nu_e contamination is 1-2%, 
and is THE SAME SIGN as the nu_mu, so you couldn't even use 
the charge of the tau to separate the two...

>> done

table 5:  I think it's not worth having all those columns with "no" 
there, you should just say that the nu_e content in the beam 
is small and too poorly known to do much precise work on nu_e to 
anything.  (in the figure caption) 

>> I like having "no's" ... Fritz has improved the cosmetics.

table 6: it might be better to have 2 columns of delta m2, 
delta m_23 and delta m_12.  that way you can get miniboone
correctly identified.  the thing is, even if lsnd is correct, 
minos should still be able to look for nu_mu disappearance, 
which at that distance would have a little nu_mu to nu_e but 
would also have plenty of nu_mu to nu_tau and 
as such would still be a measure (although with worse statistics) 
of delta m_23^2.  it's not that lsnd has to be wrong for minos et al to 
measure something...

>> The experiments only effectively measure the leading delta m^2,
>> so introducing an additional blank column seems unnecessary. 
>> However, your point is well taken ... changed table caption 
>> to spell out its the leading dm2.

page 53: analysis cuts for steel/scint: pt2 should be > 2GeV ^2, not
4GEV^2.

>> done

mention somewhere in the tau discussion that Opera sees 30% 
efficiency, for a 20GeV neutrino beam (on average, and that in general the 
tau detection efficiency is a function of energy and will be low!) 

>> 29% efficiency is explicitly stated in the OPERA paragraph.

On page 39: "events where the primary muon was less than 2GeV"
(I figured that number out when I made the new punch-charm plot) 

>> done

page 54:  in the introduction to the measurements section, I would realy 
spell out what we're going to do:  maybe put bullets or a list of the 
different measurements instead of having them be part of one long 
sentence:  

but then I would spell things out something like this: 

"This section will describe several studies that have been performed  
to investigate proposed detectors at a neutrino storage ring.  
The two muon detector technologies used in these studies  
correspond to either a steel scintillator detector or a 
liquid argon TPC.  
Since different studies make different assumptions about backgrounds 
and efficiencies it is difficult to make line-by-line comparisons. 
However, it will be shown in this section how both detectors, with 
reasonable assumptions about backgrounds and efficiencies, can 
make very impressive measurements at a neutrino storage ring.  
To understand how these measurements work it is helpful to first 
show the physics signal with no backgrounds but only detector 
resolutions, and then go on to show what a real experiment might 
actually see given backgrounds and cuts.  

---------------------------------------------------------------------
Anyway, I think that it would be good to warn people as early as possible
that you are going to be showing things with and without backgrounds
and efficiencies...even in the first section!  

>> Intro changed to "spell out" the list of things in the section.
>> Also added text to spell out differences in calcs.

Thanks for fielding all these comments--I'll give you the paper copy 
of my comments shortly (remember, there are comments on pages that haven't
been indicated in this email message).  

Sincerely, 
Debbie


Replies to written comments  on sections 2 and 4


Date: Wed, 29 Mar 2000 21:16:27 -0600 (CST)
From: Heidi Schellman <schellma>
Subject: response to debbie section 2 comments
To: dharris@fnal.gov, sgeer@fnal.gov, schellman@fnal.gov

Added _{cm} and an explanation 

 $x\equiv 2E_\nu/m_\mu$, $\theta_{cm}$ 

and later.

($\cos\theta_{lab}\simeq1$) are relevant to the neutrino flux for
long-baseline experiments; in this limit

I added  sentences to 2.1

Neutrinos scatter from nuclei via two major processes, neutral current
processes in which a $Z^0$ boson is exchanged and the neutrino remains
in the final state, and charged current processes in which a charged
$W$ boson is exchanged and the neutrino is transformed into the corresponding
charged lepton in the final state. Neutrino charged-current  scattering 
cross-sections are shown as a function of
energy in Fig.~\ref{tau_fig}. 
At low energies the neutrino scattering cross section is dominated by
quasi-elastic scattering and resonance production. 
However, if $E_\nu$ is greater than $\sim10$~GeV, 
the total cross section is  dominated by deep inelastic scattering 
and is approximately\cite{CCFRsigma}:

I have not added a quasi-elastic description here as Debbie requested
as it should be in some more detailed section.

Page 12
Tau neutrino charged current  interaction rates are substantially less than 
the corresponding
$\nu_e$ and $\nu_\mu$ rates, 
especially near the tau production threshold of $\sim 3.3$~GeV.
%Above threshold the $\tau$--lepton mass terms in the leptonic
%current cannot be ignored, allowing the axial vector structure
%functions $W_4$ and $W_5$ to play a non-negligible role.
The neutral current rates should be the same as those for electron
and muon neutrinos.
Figure~\ref{tau_fig} shows the calculated~\cite{goodman} 
ratio of $\nu_\tau / \nu_\mu$ CC 
interaction rates as a function of the neutrino energy. 
Near threshold, contributions
from quasi--elastic and resonance production dominate.
If the $\nu_\tau$ cross sections from 
Ref.~\cite{casper} are used, the predicted event rates are 20--30\%
higher.

Burt wanted us to use Casper - what's the plan here (and what's the reference?

Dr. Casper turns out to have done a stint on Aleph which makes finding
his papers hard. He's done something like 20 with tau in the name, all at 91 
GeV.

I rechecked the number of interactions upstream and, for all processes
neutral and charged current get about 30 interactions/spill not the 140
I had.  I will now recheck again!