I tried to compare data on mult_pi per A_part between HADES, FOPI, TAPS, and KAOS.
But as you know, data require several corrections, so this comparison is alwayd biased, like e.g. in Reisdorf's paper for FOPI,TAPS,KAOS comparison.
The corrections:
- recalculation of KAOS data from cross section to multiplicity. Kaos used sigma_reaction 5.9+-0.4 b, while we in HADES get 6.8+-0.4 b from Glauber. Would be nice to get somewhere some reliable independent value.
- recalculation from energy 1.0 ! GeV to our energy 1.23 ! GeV I use here factor 1.36, error is hopefuly small.
- TAPS and KAOS measured at or close to midrapidity, then assumed isotropic distribution. Knowing that there is quite strong polar asymmetry we can correct it, e.g. by factor 1.25 used by Reisdorf (for A2= 1.0 the correction is 1.33, but at mean p_cm between 100 and 200 ! MeV A2<1).
- determination of centrality (A_part) can be also different in different experiments and influence data for comparison
here I did nothing, just believed what was published.
The result for m_pi per Apart at 1.23 !GeV is (as you can see in detail below):
| KAOS |
KAOS* |
TAPS |
FOPI |
HADES |
| 0.154+-0.018 |
*0.86 CS 0.132+-0.015 |
0.117+-0.026 |
0.173+-0.016 |
0.139+-0.008 |
*0.86 scalling with cross-section : 5.9/6.8
We can add then ! KaoS point (if we agree on the procedure of calculation) into Fig.6 on the paper.
One can also compare pt distributions at midrapidity as it is done in Senger&Stroebele review in Fig. 3.2. if we manage to get the exp. points from the three experiments.
Still there will be the same problem with corrections which influence the normalization factor.
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GosiaSudol - 24 Jun 2019