p_lab plots for pi+ from C+C at 1 and 2A GeV are compared to pi+ from KAOS.
TAPS data points are from Ch. Sturm (published in his thesis, page 81, Fig.4.7), and show d(sigma)/dp_lab at 44+-4 and 54+-4 deg for 1A GeV, and at 32+-4 deg. and 40+-4deg. for 2A GeV (region close to midrapidity). The HADES points are re-calculated from multiplicity to cross section assuming total cross section 950 mb, and corrected to minimum bias by a ratio of number of participants 6./8.61 and 6./8.38 for 1 and 2 GeV, respectively.
2 figures show the comparison for 1 and 2 GeV

  • c1c:

  • c2c:

The same figures in the linear scale are also attached. For 1 GeV data we have almost perfect agreement, for 2 GeV our data are systematically lower than the KAOS points at low momenta region, just outside the error bars (about 10% difference).
There can be problem with upper range in momenta of our data. When pi/p ratio is low, we do not separate protons and pi+ already at momenta below 1000 MeV/c. For 1 GeV I already cut points with p_lab above 775 and 875 Me/c for 44 and 54 degrees, respectively. For 2 GeV, it probably should be done for p_lab > 900 MeV/c for the 40 deg. data.

Comparison of the cross sections within KAOS acceptance (p_lab > 175 MeV/c):
                  HADES              KAOS    p_lab>175MeV/c
1GeV 44 deg        46+-3+-3         46+-2
     54            29+-1.5+-2       29+-2

                  HADES              KAOS
2GeV 32 deg        173+-9+-12      185+-5
     40            120+-6+-9       129+-4


Errors of our data: 1st error is a 5% error of the efficiency correction, the 2nd is a 7% error of the correction to min. bias.

-- PavelTlusty - 02 Dec 2008

  • c1c liny:
    c1c liny

  • c2c liny:
    c2c liny
Topic attachments
I Attachment Action Size Date Who Comment
c1c_pip_hades_kaos_liny.gifgif c1c_pip_hades_kaos_liny.gif manage 24.0 K 04 Dec 2008 - 10:38 PavelTlusty c1c liny
c1c_pip_hades_kaos_logy.gifgif c1c_pip_hades_kaos_logy.gif manage 18.7 K 02 Dec 2008 - 15:53 PavelTlusty c1c
c2c_pip_hades_kaos_liny.gifgif c2c_pip_hades_kaos_liny.gif manage 25.4 K 04 Dec 2008 - 10:39 PavelTlusty c2c liny
c2c_pip_hades_kaos_logy.gifgif c2c_pip_hades_kaos_logy.gif manage 19.2 K 02 Dec 2008 - 15:54 PavelTlusty c2c
Edit | Attach | Print version | History: r4 < r3 < r2 < r1 | Backlinks | View wiki text | Edit WikiText | More topic actions...
Topic revision: r3 - 04 Dec 2008, PavelTlusty
This site is powered by FoswikiCopyright © by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding Hades Wiki? Send feedback
Imprint (in German)
Privacy Policy (in German)