[b1_ana] draft proposal v02

[Jian-ping Chen]

Dustin,

For the study of asymmetry changes due to drift in charge measurement and
detector efficiency, the transversity experience can only be used for
detectors, not for charge, since the conditions for charge/current 
measurement
are completely different (10 uA vs 100 nA). So we need information from 
g2p/GEp
to say anything about charge/current.

For HRS detector drift during transversity , we measured detector response
(normalized yield for same condition) over long period and see little 
change (<1%).
The measurements were usually limited to about 1% precision.
Not worrying about fluctuations (which does not contribute to overall 
drift), this
means that for short time (20 minutes period when we did target spin flip),
the detector drift should be less than 1%*20minte/3 months and significantly
less than 10^-3. We just took it as 10^-3 to be conservative.The total 
contribution to
our false asymmetry is 10^-3/sqrt(N_pairs)  < 10^-4 (since we have more 
than 100 pairs).
This is also confirmed from checking false asymmetries.

To translate to our proposal, if we can keep detector response to be stable
at 1% in 3 months, then in 12 hours, stability should again be better 
than 10^-3,
the total contribution to the systematic should be 
10^-3/sqrt(N_pair)=3*10^-4 (for 10 pairs).
(Probably not use conservative number, we can reach 1*10^-4).

For the charge, if we can measure to 1% in 1s, in a typical run of 1 
hour, we
should have more than enough statistics for 10^3. Need to check 
stability from
data (g2p/GEP) to see if data stays at that level of stability and also 
to check at
12 hours time scale. If it stays at 10^-3, then we have the same
systematic uncertainty of 3*10-4. If it is better, then we can do better.

I believe reaching the combined uncertainty (both charge and detector) 
of 3*10-4 is
reasonable. But better to have data to support it

Cheers.

Jian-ping



On 5/5/2013 3:03 AM, Dustin Keller wrote:
> here is what i was thinking, let me know if we want to add something
> like this and we can clean it up a bit and add some details.
>
> dustin
>
> On Sun, 5 May 2013, Karl Slifer wrote:
>
>> Hi Oscar,
>>
>> I modified this eq as you suggested to show the explicit dependence on Q
>> and e.
>>
>> -Karl
>>
>>
>> [image: Inline image 3]
>>
>> ---
>> Karl J. Slifer
>> Assistant Professor
>> University of New Hampshire
>> Telephone : 603-722-0695
>>
>>
>> On Fri, May 3, 2013 at 9:38 PM, Oscar Rondon-Aramayo <
>> or at cms.mail.virginia.edu> wrote:
>>
>>> Hi,
>>>
>>> To further remove any confusion about our method and its errors, I 
>>> suggest
>>> that instead of writing eq. (19) in terms of charge normalized, 
>>> efficiency
>>> corrected counts, we display the charges and efficiencies 
>>> explicitly, and
>>> use raw counts. Although we stated the kind of counts we are using 
>>> in that
>>> eq. just above it, it seems Steve missed it.
>>>
>>> Per eqs. (32) and (33) in the appendix 2.2.3, this means just moving 
>>> Q's
>>> and
>>> epsilons to the l.h.sides, since N1 and N are indeed raw counts 
>>> there, and
>>> don't make any approximations, like Q1 ~ Q, etc.
>>>
>>> Then, the l.h.s. of eq. (34) would be
>>>
>>> (Q/Q1)*(e/e1)*(N1/N) and
>>>
>>> eq. (19) becomes
>>>
>>>   Azz =  2/(f*Pzz)*[(Q/Q1)*(e/e1)*(N1/N) - 1]
>>>
>>> where it's evident that Q's and e's are normalizations or scale 
>>> factors,
>>> just like f and Pzz, and change the text above the equation to say raw
>>> counts, not normalized and corrected ones.
>>>
>>> I don't see any other way to make it any clearer.
>>>
>>> And, of course, we need to emphasize somewhere that the statistical 
>>> error
>>> is
>>> always based on the RAW counts.
>>>
>>> Cheers,
>>>
>>> Oscar
>>>
>>>
>>>
>>> On Fri, 3 May 2013 17:43:55 -0400
>>>   Karl Slifer <karl.slifer at unh.edu> wrote:
>>>> Hi all,
>>>>
>>>> I got a ton of comments, and I think I've implemented them all.  I 
>>>> think
>>>> the most substantial pertain to the following: (equation numbers 
>>>> refer to
>>>> the attached draft)
>>>>
>>>> Eq 17 and 19: Azz expressed as ratio - 1 as suggested by Oscar
>>>>
>>>> Eq 22 : Total time expressed in terms of R_T as noted by Patricia and
>>>> concurred by Ellie and Oscar.
>>>>
>>>> Page 23 Charge determination systematic : modified to reflect Oscar 
>>>> and
>>>> JP's suggestions
>>>>
>>>> There were a lot more, so please double check that your suggestions 
>>>> have
>>>> been satisfactorily included.
>>>>
>>>> The overhead and target sections are still in progress. Anyone have 
>>>> time
>>>> to help with that?
>>>>
>>>> thanks,
>>>>
>>>> Karl
>>>>
>>>>
>>>> ---
>>>> Karl J. Slifer
>>>> Assistant Professor
>>>> University of New Hampshire
>>>> Telephone : 603-722-0695
>>>
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>>
>
>
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