[b1_ana] Fwd: comments/questions to PR12-13-011
Elena Long
ellie at jlab.org
Mon Jun 10 15:44:05 EDT 2013
Good afternoon,
My apologies, the numbers I gave for Miller are incorrect. I actually
listed Azz instead of the sum. The actual Miller numbers are:
For Miller, the integrated sums over particular ranges are:
Range & PDF Type & Sum
0.0001 < x < 1 & CTEQ5 & -0.0295
0.0001 < x < 1 & MRST2001LO & -0.0316
0.0001 < x < 1 & MSTW2008LO & -0.0208
0.0001 < x < 0.15 & CTEQ5 & -0.0295
0.0001 < x < 0.15 & MRST2001LO & -0.0315
0.0001 < x < 0.15 & MSTW2008LO & -0.0208
0.0001 < x < 0.5 & CTEQ5 & -0.0296
0.0001 < x < 0.5 & MRST2001LO & -0.0316
0.0001 < x < 0.5 & MSTW2008LO & -0.0209
0.5 < x < 0.998 & CTEQ5 & +0.0001
0.5 < x < 0.998 & MRST2001LO & +0.0000
0.5 < x < 0.998 & MSTW2008LO & +0.0001
0.15 < x < 0.5 & CTEQ5 & -0.0001
0.15 < x < 0.5 & MRST2001LO & -0.0001
0.15 < x < 0.5 & MSTW2008LO & -0.0001
All of the other numbers should be fine.
Take care,
Ellie
Elena Long, Ph.D.
Post Doctoral Research Associate
University of New Hampshire
elena.long at unh.edu
ellie at jlab.org
http://nuclear.unh.edu/~elong
(603) 862-1962
On Mon 10 Jun 2013 03:18:00 PM EDT, Elena Long wrote:
> Also, for just the x-range we're looking over, we get:
>
> ------------------------------------------------------------------------------------------
> For Miller, the integrated sums over particular ranges are:
>
> Range & PDF Type & Sum
>
> 0.15 < x < 0.5 & CTEQ5 & -0.00467
> 0.15 < x < 0.5 & MRST2001LO & -0.00467
> 0.15 < x < 0.5 & MSTW2008LO & -0.00467
>
> ------------------------------------------------------------------------------------------
> For Misak, the integrated sums over particular ranges are:
>
> Range & PDF Type & Sum with vn & Sum with lc
>
> 0.245 < x < 0.5 & CTEQ5 & -0.000191 & -0.000141
> 0.245 < x < 0.5 & MRST2001LO & -0.000152 & -0.000112
> 0.245 < x < 0.5 & MSTW2008LO & -0.000184 & -0.000136
>
> ------------------------------------------------------------------------------------------
> For Kumano, the integrated sums over particular ranges are:
>
> Range & PDF Type & Sum Without Sea & Sum With Sea
>
> 0.15 < x < 0.5 & CTEQ5 & -0.000700 & -0.00053
> 0.15 < x < 0.5 & MRST2001LO & -0.000553 & -0.00030
> 0.15 < x < 0.5 & MSTW2008LO & -0.000718 & -0.00053
>
>
> Take care,
> Ellie
>
>
> On Mon 10 Jun 2013 03:09:34 PM EDT, Elena Long wrote:
>>
>> test of Close-Kumano sum rule - it is very hard to do such test with
>> limited coverage in x, may be some
>> estimates of contribution measured/extrapolated can be done for
>> specific models. For the models mentioned
>> on page 17 - can one get some idea what would be the contribution in
>> measured range?
>>
>> RESPONSE : Yes, this in an excellent suggestion. G. Miller and M.
>> Sargian have provided us their curves. We need to integrate to see the
>> contributions for x<0.15 and x>0.5. (Ellie, I think you have these
>> now. Can you look into this?)
>>
>> ------------------------------
>>
>> Ellie:
>> The calculations below show the integral over certain x ranges for
>> three different types of PDFs used in the calculation of b1. They were
>> calculated using step sizes of x=0.001 with INT(b1,x) =
>> SUM(b1(x)*stepsize) where b1(x) is a calculate value of b1 at a
>> particular x value.
>>
>> ------------------------------------------------------------------------------------------
>> For Miller, the integrated sums over particular ranges are:
>>
>> Range & PDF Type & Sum
>>
>> 0.0001 < x < 0.998 & CTEQ5 & -0.00931
>> 0.0001 < x < 0.998 & MRST2001LO & -0.00931
>> 0.0001 < x < 0.998 & MSTW2008LO & -0.00931
>>
>> 0.0001 < x < 0.15 & CTEQ5 & +0.00200
>> 0.0001 < x < 0.15 & MRST2001LO & +0.00200
>> 0.0001 < x < 0.15 & MSTW2008LO & +0.00200
>>
>> 0.0001 < x < 0.5 & CTEQ5 & -0.00267
>> 0.0001 < x < 0.5 & MRST2001LO & -0.00267
>> 0.0001 < x < 0.5 & MSTW2008LO & -0.00267
>>
>> 0.5 < x < 0.998 & CTEQ5 & -0.00664
>> 0.5 < x < 0.998 & MRST2001LO & -0.00664
>> 0.5 < x < 0.998 & MSTW2008LO & -0.00664
>>
>> ------------------------------------------------------------------------------------------
>> For Misak, the integrated sums over particular ranges are:
>>
>> Range & PDF Type & Sum with vn
>> & Sum with lc
>>
>> 0 < x < 0.245 & N/A & Model does not apply
>>
>> 0.245 < x < 0.998 & CTEQ5 & -0.000181 & -0.000135
>> 0.245 < x < 0.998 & MRST2001LO & -0.000146 & -0.000109
>> 0.245 < x < 0.998 & MSTW2008LO & -0.000172 & -0.000129
>>
>> 0.245 < x < 0.5 & CTEQ5 & -0.000191 &
>> -0.000141
>> 0.245 < x < 0.5 & MRST2001LO & -0.000152 & -0.000112
>> 0.245 < x < 0.5 & MSTW2008LO & -0.000184 & -0.000136
>>
>> 0.5 < x < 0.998 & CTEQ5 & +0.000010 &
>> +0.000006
>> 0.5 < x < 0.998 & MRST2001LO & +0.000006 & +0.000003
>> 0.5 < x < 0.998 & MSTW2008LO & +0.000012 & +0.000007
>>
>> ------------------------------------------------------------------------------------------
>> For Kumano, the integrated sums over particular ranges are:
>>
>> Range & PDF Type & Sum Without Sea&
>> Sum With Sea
>>
>> 0.0001 < x < 0.998 & CTEQ5 & +0.00183 &
>> +0.00820
>> 0.0001 < x < 0.998 & MRST2001LO & +0.000604 & +0.0104
>> 0.0001 < x < 0.998 & MSTW2008LO & +0.000266 & +0.00767
>>
>> 0.0001 < x < 0.15 & CTEQ5 & +0.00296 &
>> +0.00901
>> 0.0001 < x < 0.15 & MRST2001LO & +0.00147 & +0.0109
>> 0.0001 < x < 0.15 & MSTW2008LO & +0.00143 & +0.00849
>>
>> 0.0001 < x < 0.5 & CTEQ5 & +0.00226 &
>> +0.00848
>> 0.0001 < x < 0.5 & MRST2001LO & +0.000917 & +0.0106
>> 0.0001 < x < 0.5 & MSTW2008LO & +0.000712 & +0.00796
>>
>> 0.5 < x < 0.998 & CTEQ5 & -0.00043
>> & -0.00028
>> 0.5 < x < 0.998 & MRST2001LO & -0.000313 & -0.0002
>> 0.5 < x < 0.998 & MSTW2008LO & -0.000446 & -0.00029
>>
>>
>>
>> Take care,
>> Ellie
>>
>> Elena Long, Ph.D.
>> Post Doctoral Research Associate
>> University of New Hampshire
>> elena.long at unh.edu
>> ellie at jlab.org
>> http://nuclear.unh.edu/~elong
>> (603) 862-1962
>> On 06/09/2013 11:07 PM, Karl Slifer wrote:
>>>
>>>
>>> Hi all,
>>>
>>> Below please find a draft response to the readers. I'd appreciate
>>> any/all feedback.
>>>
>>> Thanks to Oscar and Dustin for sending comments already. I hope I
>>> have incorporated them satisfactorily, but let me know if not.
>>>
>>> Dustin : any ETA for the updates to the technote? Ideally we can send
>>> them this short email and then provide your note for the full details.
>>> Most important would be to clarify the overall drift numbers, as I
>>> had the same confusion that Ellie raised.
>>>
>>> I'll have time to work on this tomorrow morning and early afternoon,
>>> but have to leave for DC mid afternoon. I'd love to get a response
>>> to Ewa before then if possible.
>>>
>>> thanks much,
>>>
>>> -Karl
>>>
>>>
>>> -----------------------------
>>>
>>> The measurement is very sensitive to the systematic effects and good
>>> control of them is the
>>> key point. Therefor I would like to know if there are any estimates
>>> of expected size of effects from:
>>>
>>> RESPONSE: We agree with the TAC assessment that systematic errors
>>> from drifts must be mitigated, but
>>> that they are manageable with a combination of
>>> hardware upgrades and a dedicated collaboration
>>> effort. We note that the recent g2p experiment
>>> involved a similar situation where a significant
>>> commitment was made to install and run this
>>> polarized target, but separate groups were tasked
>>> with substantial tasks of beamline, DAQ and
>>> detector upgrades. We are grateful to the TAC for
>>> pointing out several effects which were not
>>> explicitly discussed in our submitted proposal. We
>>> have written a short note discussing each of
>>> these and conclude that the overall systematic
>>> uncertainty is still of the same order as
>>> estimated in the proposal.
>>>
>>> 1. beam - one aspect is the stability in terms of position and divergency
>>> this can change acceptance and produce false asymmetries
>>>
>>> RESPONSE: (The TAC report pointed out that the false asymmetries from
>>> beam position drifts are easily
>>> removed by "regression". Can someone fill in the
>>> details? I assume that this just means
>>> that the parity feedback on position is very
>>> good, but we need some numbers/examples to
>>> back this up. This is dealt with in section
>>> 1.1.4 of the note, but there are few details.)
>>>
>>> 2 beam polarization - how the unpolarized beam will be obtained what
>>> kind of effects are
>>> expected from beam polarization (ie. to which level exact
>>> averaging of opposite beam polarity
>>> is needed and how the phase space of the beam is polarization
>>> dependent)
>>>
>>> RESPONSE: JLab E06-010 (Transversity) spin-averaged a highly
>>> polarized (~80%) beam in order to
>>> obtain an "unpolarized" beam. The parity
>>> feedback allowed for knowledge of the residual
>>> beam polarization at the 2.2*10^{-5} level,
>>> according to the lumi monitors. Please see attached
>>> plot, which shows the beam asymmetry from that
>>> experiment.
>>>
>>>
>>> 3. temperature effects on the efficiency (and stability of the
>>> detectors allignment) - proposed scheme
>>> of polarization reversals will give data with target
>>> polarization during the day and unpolarized
>>> at night or vice versa. This can introduce false asymmetry
>>> related to any kind of temperature
>>> dependence in efficiency or allignment. Was it estimated ? Are
>>> there any studies of this kind of effects
>>> in previous experiments?
>>>
>>> RESPONSE: (This could be addressed by the transversity slides, but
>>> I'm not sure if the pion yield plot
>>> addresses this. The main sensitivity to
>>> temperature will be the BCMs and Dave has plans
>>> to isolate them, but I don't have any details of
>>> that yet.)
>>>
>>>
>>>
>>> 4. for the drift of efficiency and its time dependence (page 25)
>>> linear evolution in time is assumed.
>>> for which effects it is justified? It is clear that for example
>>> changes in packing factor of dilution factor
>>> can have "step like" characteristics. Are there any ideas to
>>> what level such effects can be controlled
>>> during the run?
>>>
>>> RESPONSE : (Linear and sinusoidal drifts are the only type that I've
>>> seen. Higher orders could theoretically
>>> be present, but if they were I suppose they
>>> would become an issue for all experiments, not just ours.)
>>> "Step-like" changes in the packing factor or
>>> dilution factor have only been observed once in 700 hours
>>> of running the polarized target. It was
>>> immediately obvious from the change in polarization. If it
>>> occurs during this experiment, it would impact
>>> only a single pol/unpol cycle, which is either a 12 hour or
>>> 24 hour portion of data. This data would need
>>> to be either discarded or handled with care.
>>>
>>>
>>> In the proposal "consistency checks on measured cross section for
>>> each run" is mentioned.
>>> What precisely is meant? At what level it can be done for the
>>> proposed measurement? Please give
>>> more detail, especially on the precision of such test.
>>>
>>> RESPONSE : Typically we can monitor the unpolarized yields to the
>>> better than 1% level. Luminosity monitors
>>> installed around the beamline can be monitored
>>> to the ?? level (J.P.?)
>>>
>>>
>>> The other test mentioned in the proposal, where I would like to have
>>> some more comments on is "the
>>> measurements of dilution and packing factor - with carbon target "-
>>> what exactly is planed and which
>>> precision can be obtained? is it included in the beam time estimate?
>>>
>>> RESPONSE: The polarized target material is deuterated ammonia (ND_3).
>>> We determine the dilution factor by the ratio of
>>> simulated radiated rates on D to total
>>> rates. The pf is calculated by interpolating the
>>> ND3 measured rates between simulated
>>> rates for different packing factors, with the
>>> simulation calibrated by the measured rates
>>> on a carbon target of known thickness. The
>>> systematic uncertainty of this process
>>> is at the 4% level. It is important to note that
>>> the dilution factor is a scale factor so the
>>> uncertainty is an overall scale factor. We have
>>> 6 hours assigned to this task in our overhead table 4.
>>> This is a relatively short time since all that is
>>> needed is to measure the unpolarized cross section
>>> from a carbon disk, and the rate is usually quite
>>> high.
>>>
>>>
>>> It would be interesting to see comparison of expected statistical
>>> errors in each bin with expected false
>>> asymmetries from time variation of beam and efficiency/acceptance.
>>>
>>> RESPONSE: We now have plots graphically showing the full systematic
>>> uncertainty, both from the normalization
>>> dependent factors and the possible drifts. The
>>> plots are shown in the technote.
>>>
>>>
>>> What are the arguments for proposed binning in x?
>>> the last bean is clear, as much data in this configuration as
>>> possible, but splitting of SHMS data taking
>>> in 3 intervals is not discussed from the optimalization point of
>>> view, it would be good to have it in the
>>> presentation.
>>>
>>> RESPONSE : (Hmm. Not sure how to answer this. Simple answer is that
>>> the points represent the largest
>>> spread in x that allows a reasonable overlap
>>> with HERMES in a reasonable amount of beam-time.
>>> Ellie has optimized to avoid large systematics
>>> from F1, and suppression of rates. )
>>>
>>>
>>>
>>> In general, also the authors call the measurement "ratio method" it
>>> is the cross section difference method
>>> as the two data sets are taken at different time. Advantage of "ratio
>>> method" can be fully used when two
>>> target cels are exposed at the same time and next order is reversed.
>>> Such configuration allows several
>>> additional cross checks, but requires two cell target.
>>>
>>> RESPONSE : We have examined a two cell configuration, and while it is
>>> attractive for the reason you point
>>> out, it was not clear at the time of the
>>> proposal submission that it significantly reduced the
>>> overall systematic uncertainty. We will
>>> continue to examine this option and are open to using
>>> it if we are convinced the systematic
>>> improvement is significant.
>>>
>>>
>>> test of Close-Kumano sum rule - it is very hard to do such test with
>>> limited coverage in x, may be some
>>> estimates of contribution measured/extrapolated can be done for
>>> specific models. For the models mentioned
>>> on page 17 - can one get some idea what would be the contribution in
>>> measured range?
>>>
>>> RESPONSE : Yes, this in an excellent suggestion. G. Miller and M.
>>> Sargian have provided us their curves.
>>> We need to integrate to see the
>>> contributions for x<0.15 and x>0.5. (Ellie, I think you have these
>>> now. Can you look into this?)
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> b1_ana mailing list
>>> b1_ana at jlab.org
>>> https://mailman.jlab.org/mailman/listinfo/b1_ana
>>
>>
>>
>>
>> _______________________________________________
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>> --
>> Elena Long, Ph.D.
>> Post Doctoral Research Associate
>> University of New Hampshire
>> elena.long at unh.edu
>> ellie at jlab.org
>> http://nuclear.unh.edu/~elong
>> (603) 862-1962
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