[Olympus] remaining program

[Jan C. Bernauer]

Hi,

  yes, but that means only the relative change, not when switching the 
species, right?

If we have a possible unknown offset between species, I would vote for 
another try.

Best,
Jan


On 20.12.12 17:44, Douglas Kenneth Hasell wrote:
> Hi,
>
> 	I would vote to NOT have another energy calibration run.  It is unfortunate that the last measurement was unsuccessful but looking at the existing monitoring of the energy with Uwe I am reasonably confident that the variations are on the order of 10^-4 or at least can be corrected for to this level.
>
> Cheers,
> Douglas
>
> On Dec 20, 2012, at 4:43 PM, Brinker, Frank wrote:
>
>> Dear all,
>> Beside the program you discuss here I want to ask whether another energy
>> calibration is wanted.
>> We have a calibration for e+ and e- from mid of November  and for e+
>> from Dec 22nd.
>> A try for e- in December was not successful.
>>
>> I can offer to try another calibration in the night from Dec 31st to Jan
>> 1st.
>>
>> Best regards
>> Frank Brinker
>>
>>> -----Original Message-----
>>> From: olympus-bounces at mit.edu [mailto:olympus-bounces at mit.edu] On
>>> Behalf Of Michael Kohl
>>> Sent: Thursday, December 20, 2012 2:14 PM
>>> To: olympus at mit.edu
>>> Subject: [Olympus] remaining program
>>>
>>> Dear all,
>>>
>>> we have collected 3.2 fb^-1 so far, almost close to the design
>>> luminosity.
>>>
>>> For the 12-day addendum we should make a plan for a set of additional
>>> measurements that could be helpful for the analysis.
>>>
>>> Here is my proposal for low-luminosity running:
>>> -run all four configs (e+-,B+-) without shielding but with the
>> intensity
>>> reduced to optimze the noise, each for a day.
>>> E.g. reduce lumi by x10, expect ~3Hz elastics = 250k elastic events per
>>> day -> 20 mA current / 0.2 sccm flow;
>>> vary the magnetic field (100%, 75%, 50%, 25%) every six hours.
>>> Open up the trigger by reducing the prescale on the 3-of-4 trigger type
>>> to max out the DAQ (<30-40% deadtime).
>>>
>>> This would cost us four days of running.
>>> A data set with minimized noise can help us train and optimize the
>>> reconstruction software, rather than using "noisy" high-luminosity
>> data.
>>>
>>> A dataset with minimized moise in all four configs will show how the
>>> cancelations in the ratio occur and will help us validate the MC.
>> Varying
>>> the magnetic field in addition will serve the same purpose. The
>> statistics
>>> will be good enough for the validation at forward angles, where also
>> the
>>> systematic effects on the single-polarity ratio were the largest.
>>> In the end we will need to be able to trust the MC for B+ at low
>> epsilon.
>>>
>>> At low luminosity, a trigger which is more more open also allows to
>> verify
>>> TOF and trigger efficiencies, and to break any inefficiencies further
>> down
>>> as a function of channels, coordinates etc.
>>>
>>> We should start producing that set of measurements beginning on
>> Saturday,
>>> so that it could be finished by Wednesday. If it takes longer we still
>>> have a few days left. Any final remaining days would be used to further
>>> improve the statistics.
>>> Frank Brinker also would like to do another Touchek energy measurement,
>>> probably on Dec 31 / Jan 1.
>>>
>>> If you have further ideas or wishes, please bring them up.
>>>
>>> Best regards
>>>   Michael
>>>
>>>
>>>
>>> +---------------------------------------------------------------------
>>> | Dr. Michael Kohl, Assistant Professor and Staff Research Scientist
>>> | Physics Department, Hampton University, Hampton, VA 23668
>>> | Jefferson Lab, C117, 12000 Jefferson Avenue, Newport News, VA 23606
>>> | Phone: +1-757-727-5153 (HU), +1-757-269-7343 (Jlab)
>>> | Fax:   +1-757-728-6910 (HU), +1-757-269-7363 (Jlab)
>>> | Email: kohlm at jlab.org
>>> | Cell:  +1-757-256-5122 (USA)
>>> |
>>> | Deutsches Elektronen-Synchrotron DESY, Bd. 66, Rm. 6,
>>> | Phone: +49-40-8998-6406, Cell: +49-171-101-1967
>>> +---------------------------------------------------------------------
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>>
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>
>                                                      Cheers,
>                                                              Douglas
>
> 26-415 M.I.T.                                 Tel: +1 (617) 258-7199
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>
>
>
>
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