[d2n-analysis-talk] Target Mass Corrections

[Brad Sawatzky]

Thanks Matt.  I think one of the other open questions was whether the QE
contribution needed to be computed using a Nachtmann formalism before
subtraction (at least I think that's what Oscar was meaning...)

-- Brad

On Thu, 11 Apr 2013, posik at jlab.org wrote:

>  Hi all,
> 
>   A few days ago Brad forwarded an email which had posed the question of
> how target mass corrections were going to be handled, So I have been
> reading about target mass corrections and what I have found is that
> there is a variable called the Nachtmann variable, xi, that is related
> to x Bjorken. By plotting xi vs x, the significance of the target mass
> corrections can be seen by how much xi deviates from the xi = x curve.
> 
>   In light of this, I have calculated xi using the neutron mass (0.940
> GeV) for various Q2 values, as well as for our data.
> 
>  Below I show the Nachtmann variable as a function of x. The dashed line
> represents xi = x (i.e. Q2 = infinity and no mass corrections are
> needed). There are several other curves where the Nachtmann variable was
> calculated at various constant Q2 values. These curves show that as Q2
> increases the curves approach the xi = x curve. The red and blue markers
> represent our 4 and 5 pass data, which show that we fall pretty close to
> the xi = x curve, with a slight deviation towards higher x. Given the
> small deviation at high x from the xi = x curve and the fact that d2 at
> x > 0.6 is around an order of magnitude smaller than d2 at x < 0.6, I do
> not think we need to worry about target mass corrections.
> 
>   Please let me know if you have any comments or suggestions.
> 
> Thanks
> Matt

-- 
Brad Sawatzky, PhD <brads at jlab.org>  -<>-  Jefferson Lab / Hall C / C111
Ph: 757-269-5947  -<>-  Fax: 757-269-5235  -<>- Pager: brads-page at jlab.org
The most exciting phrase to hear in science, the one that heralds new
  discoveries, is not "Eureka!" but "That's funny..."   -- Isaac Asimov