LVL1 trigger bias in SEP05 - ArKCl at 1.75 A GeV - charged pion multiplicities

Addendum to previous page LVL1TriggerBiasInSEP05 concentrated on track multiplicities

This page tries to show the effect of the LVL1 trigger in the SEP05 experiment on selection of the reaction events.

We checked the multiplicity of charged pi mesons in the data samples taken with various LVL1 triggers:
For explanation of trigger conditions see LVL1TriggerBiasInSEP05.


Table 1: pi+/pi- multiplicities per event, in HADES acceptance, efficiency corrected, empty target subtracted.

trigger             EXP             UrQMD       UrQMD(4pi)

ST              0.027/ 0.034
min bias        0.88 / 1.08*    1.06 / 1.30    1.75 / 2.05
M4mb            1.27 / 1.55     1.35 / 1.70    2.25 / 2.65 
M4              1.53 / 1.85  
M16mb           1.92 / 2.33     2.17 / 2.70    3.51 / 4.16 
M16             1.97 / 2.38  

* for EXP min. bias was taken as multiplicity of START events divided by 0.0310, which is an estimated min. bias reaction rate, see Table 2 in LVL1TriggerBiasInSEP05.


Table 2: pi-/pi+ ratio, in HADES acceptance, efficiency corrected.

trigger        EXP             UrQMD       UrQMD(4pi)

ST             1.23
min bias       1.23             1.23        1.17
M4mb           1.22             1.26        1.18
M4             1.21  
M16mb          1.21             1.24        1.19
M16            1.21  

Table 3: pi content enhancement in various triggers:

triggers           EXP             UrQMD     difference   UrQMD(4pi)

M4mb /min. bias    1.44             1.29        10%          1.29
M16mb/min. bias    2.17             2.06         5%          2.02

-- PavelTlusty - 11 Jun 2009