[Eic_ct] minutes of the 03/18/ phone meeting

[Rolf Ent]

Dear all,

 	I agree with Leonid, this is indeed wy we also ended
up with a relatively large detector space, even if that costs
somewhat luminosity (luminosity without acceptance does not
help either...). You probably have to think a bit how you are
going to list the kinematics for the recoil baryons, as this
can become complicated.

 	To give some points of reference, we are pretty sure we
can detect down to one degrees, and are trying to map down to 0.5
degrees. It may even be possible to make final-focusing magnets
such that we map lower angles. Below 0.2 degree or so you are
essentially in the beam-stay-clear area for the beam, and one
would need to do tricks with measurements in the arcs, etc. Some
of this is again correlated with the momentum of the particles,
and whether they are charge-neutral or now, and then you have to
also ponder about where decay products go.

 	I have no recipe, but probably a two-dimensional angle
vs momentum plot for various recoil baryons and their products
is the least. And, probably for a variety of energies as that
comes in too.

 				Best regards,	Rolf

On Thu, 18 Mar 2010, Leonid Frankfurt wrote:

> Hi everybody,
> it is important to measure recoil particle. This is because in QCD
> many observables for semiinclusive processes depend strongly on
> the mass of associated system.cf figures in our paper B.Blok,L.Frankfurt and
> M.Strikman. If to ignore this property of QCD evolution bizarre effects
> would
> arise which contradict to common sense.  This is exactly what happen at HERA
> in the interpretation of data on the process: \gamma^*+p\J/\psi +rap gap +Y
> Best Leonid
>
>
> On Thu, Mar 18, 2010 at 7:43 PM, Dipangkar Dutta <d.dutta at msstate.edu>wrote:
>
>> Hello All,
>> Here are the minutes of today's phone meeting, they are also posted on the
>> Wiki.
>>
>> https://eic.jlab.org/wiki/index.php/EA_color_in_nuclei:_meeting_minutes_3/18/10
>>
>> == Participants ==
>>
>> ''Lamiaa El Fassi, Wim Cosyn, Gerry Miller, Dipangkar Dutta''
>>
>> Gerry gave us a quick update from the Rutger's EIC meeting
>>
>> We discussed the point that for most exclusive reactions, the lack of
>> missing mass resolution implies that, we have to detect the recoil particle
>> to
>> ensure exclusivity. In many cases the recoil is at very forward angles and
>> detection would be difficult. For each reaction under study we should list
>> the
>> kinematics for all reactions products so that the detector requirements can
>> be
>> specified.
>>
>> Progress on the reactions under study.
>>
>> * Coherent diffractive &rho;<sup>0</sup>, J/&Psi; production from nuclei
>> (Lamiaa)
>> Event generator is being modified for the collider geometry and it will be
>> used
>> with a PYTHIA code under development.
>>
>> * Exclusive &pi;, p, pp production from nuclei. (Wim)
>> Kinematics have been simulated, will also look at the kinematics of the
>> recoil
>> particle
>>
>> * diffractive di-jet, and high p<sub>T</sub> di-jet production (DD)
>> Determined to be not suitable for mEIC energies
>>
>> Gerry mentioned Mark Strikman and S. Kumano's work on a couple of new
>> observables:
>> 2-to-3 hard hadronic processes and large angle two body scattering.
>> He also mentioned that at the Rutgers meeting Stan Brodsky talked about
>> several new observables.
>>
>> We will look into these observables and their feasibility at the EIC.
>>
>>
>>
>> --
>> Dipangkar Dutta    Assistant Professor
>> Department of Physics & Astronomy
>> Mississippi State University
>> Rm 010C Hilbun Hall,  P.O. Box 5167
>> Mississippi State, MS 39762-5167
>> Ph: 662 325 3105      Fax: 662 325 8898
>> email: d.dutta at msstate.edu
>> webpage: http://ra.msstate.edu/~dd285 <http://ra.msstate.edu/%7Edd285>
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>