[Clascomment] Fwd: Re: OPT-IN: Tensor Correlations Measured in 3He(e,e′ pp)n

[Larry Weinstein]

Dear Mikhail,

Thank you for your perceptive comments.

We decided that, rather than correct the data for acceptance, we
integrated the theory calculations over the CLAS acceptance.

Fig 3 shows the cross section, the corrected number of counts divided by
luminosity and bin size.  It is not corrected for CLAS acceptance.  The
relative momentum drops to zero at p_rel approx 0.25 because a) each
nucleon has momentum p>  0.25 and b) the pair is predominantly back to
back.  This is a consequence of the angular distributions.  The total
momentum drops to zero at small p_tot due to phase space.

The acceptances mostly cancel in the ratio in figure 4.

Sincerely,
Larry

Mikhail Osipenko wrote:
>  Dear authors of He3-ppn paper,
>
>  the results presented in the paper are very interesting, however these are hard to understand in many places. E.g. Fig.2 would be more significant if corrected for efficiency/acceptance (though probably the correction does not change the picture), interplay between p1, p2 and p_leading could be avoided (using p_slow and p_fast everywhere).
>
>  Fig.3 shows the cross section (according to the text), but below I found some confusing discussion about the drope at low momenta related to a cut imposed... Indeed I would expect the cross section rising until zero momentum. Is the observable plotted in Fig.3 really the physical cross section?
>
>  Fig.4 is very impressive, but the same question as before come to my mind: is this really the ratio of cross sections? Or one have to assume that some efficiency/acceptance effects are constant in P_tot or cancels in the ratio?
>
>  Best Regards,
>                   Mikhail.
>
>

-- 
				Sincerely,
				Larry

-----------------------------------------------------------
Lawrence Weinstein
University Professor
Physics Department
Old Dominion University
Norfolk, VA 23529
757 683 5803
757 683 3038 (fax)
weinstein at odu.edu
http://www.lions.odu.edu/~lweinste/