I would like to make here few points about our background in NOV02 experimantal and simulated data.
Presented below pictures are made for the full HARD CUTS analysis. And all cuts are already applied.
Background is calculated with the like-sign same event method.

background: PLUTO true and reconstructed vs. EXP


background: PLUTO and UrQMD reconstructed vs. EXP

Just for the comparison i have added also the background from the UrQMD, where we have not only the leptons
inside, but also hadrons. One can see from this, that indeed comparing PLUTO with UrQMD,
we have more background in case of the UrQMD


Since now for the simplicity I will concentrate only on the PLUTO simulation.
SIMULATION is done with the standard PLUTO macro, including gamma conversion with the external macro.
Then the events are filtered with the acceptance matrix. There is no full analysis involved into this.

Opening angle distribution for the signal (NO PAIR CUTs)


Table below shows the reduction [%] of the true signal for the cocktail components.
pi0 74
gamma 97
eta 65
delta 68
omega Dalitz 63
omega Direct -
rho -

Opening angle distribution for the simulated signal (NO PAIR CUTs)

Looking into the background (also correlated one) opening angle will not removed a lot of it.
Please keep in mind that this is TRUE background.


By comparing the TRUE and RECONSTRUCTED background in simulation, we can see that we are close to 100 % agremment,
appart of the pi0 region. And this would means that the additional yield in the experimental background comes from hadrons most probably.

-- GosiaSudol - 27 Mar 2007
Topic attachments
I Attachment Action Size Date Who Comment
EXP_PLUTO_UrQMD_back.gifgif EXP_PLUTO_UrQMD_back.gif manage 417 K 2007-03-27 - 10:29 GosiaSudol omparison of the simulated (PLUTO & UrQMD) and experimental background
background_exp_sim_true_rec.gifgif background_exp_sim_true_rec.gif manage 417 K 2007-03-27 - 10:28 GosiaSudol comparison of the simulated (PLUTO) and experimental background
opangle_background_noCUT.gifgif opangle_background_noCUT.gif manage 528 K 2007-03-27 - 10:55 GosiaSudol Op angle distribution without any cut - background - PLUTO
opangle_signal_noCUT.gifgif opangle_signal_noCUT.gif manage 606 K 2007-03-27 - 10:39 GosiaSudol Op angle distribution without any cut - PLUTO
Topic revision: r1 - 2007-03-27, GosiaSudol
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