Folks-
I also agree with Flemming's assessment and further
think that Kharzeev's arguments are not correct, but
that we shouldn't raise that point. We should just
stick to the fact that BRAHMS cannot do much at a NEW
ENERGY in 24 hours of running as Flemming has said. If
we say BRAHMS can't do much in 24 hours of running any
beam we are essentially discounted in the discussion.
Chellis
_> ----- Original Message -----
> From: "Flemming Videbaek" <videbaek@sgs1.hirg.bnl.gov>
> To: "tom kirk" <tkirk@bnl.gov>
> Sent: Tuesday, November 13, 2001 9:17 PM
> Subject: Re: RHIC Au x Au Running at 22 GeV
>
>
> > Dear Tom,
> >
> > Unfortunately, I had not heard this until your e-mail of this evening,
and
> > have not had a chance to communicate with the rest of the Collaboration
on
> > this, and secondly will not be at BNL tomorow until mid-afternoon and
thus
> > cannot attend the 1.30- meeting.
> >
> > Though not an collaboration agreed upon statement ,my first hand
reaction
> is
> > summarized below.
> >
> > There is a physics merit to do such measurements, as discussed by Dima
> > (Though I doubt high pt will be feasible
> > even with the high solid angle by STAR and phenix).
> >
> > In the case of the BRAHMS detector with it's small solid angle
> > a 24 hours run (12 hours beam ?) with beta* of 10 and reduced luminosity
> > (1/gamma) , and shorter life time the use fullness of such beam is
highly
> > questionable . For a single setting e.g. at 90 deg or a single forward
> spec
> > angle
> > we typically need ~200K central collisions (also dN/dy is lower by
~1/3).
> > With a reduced rate .. this would
> > take ~30 hours (with beam) for a single setting, and thus of marginal
> > interest.
> >
> > We were in fact planning to collect in the remaining period high
> statistics
> > data to extend to high pt (3-4GeV/c)
> > measurements at this point where the survey for low pt (.2-1.5) is
almost
> > complete.
> > Given the choice I believe Brahms would prefer continuing the 200 GeV
run
> > particular in view of the concern given in the following paragraph.
> >
> > The amount of beam available in the last 1.5 week has certainly been
quite
> a
> > bit less than anticipated, and with the unfortunate accident at STAR
even
> > more time is being taken out of the remaining time. A 24 hour run is a
> > substantial amount of the remaining time. This, in particular if it mean
> 24
> > hours of running , and not just a 24 hours time slot set aside to this.
I
> > do honestly fear, that if such period has problems there will be
pressure
> to
> > continue outside such time and hope if agreed upon is real restricted to
a
> > fixed amount of time.
> >
> > best regards
> > Flemming
> >
> >
>
>
>
>
>
This archive was generated by hypermail 2b30 : Wed Nov 14 2001 - 09:39:29 EST