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eta prime dalitz [message #14859] Wed, 12 June 2013 02:46 Go to next message
Michael Kunkel is currently offline  Michael Kunkel
Messages: 53
Registered: June 2011
continuous participant
From: *hr.hr.cox.net
Greetings again,

When I attempt to run an etaPrime simulation, namely the dalitz decay of etaprime. I get error
Quote:

"Error in <PChannel::Initialization>: No database entry for:
eta' --> dilepton + g"


But if I look in PDalitzDecay.cc eta' is listed.

What our end goal is is to simulate the etaprime dalitz and also the etaprime pi+ pi- dilepton.

Also oddly enough if I try to set etaprime dalitz to QED =1
((PDalitzDecay * )makeDistributionManager()->GetDistribution("eta'_dalitz"))->SetUseQED(1);

This also produces error.
Quote:

Error: illegal pointer to class object (PDalitzDecay*)makeDistributionManager()->GetDistribution("eta'_dalitz ")


Here is a working macro. I know this works because I can replace eta' with eta and all is well.

void SIMULATE_EtaPrime_Dalitz(){
	
    double ebeam_min = 1.1725;
    double ebeam_max = 5.44575;
    PBeamSmearing *beam_smear = new PBeamSmearing("beam_smear", "Beam smearing");
    TF1* beam_smear_fn = new TF1("beam_smear_fn", "1./x", ebeam_min, ebeam_max);

    beam_smear->SetReaction("g + p");
    beam_smear->SetMomentumFunction(beam_smear_fn);
    makeDistributionManager()->Add(beam_smear);

    //((PDalitzDecay * )makeDistributionManager()->GetDistribution("eta'_dalitz"))->SetUseQED(1);

    gROOT->Reset();
    //PUtils::SetSeed(123); //this is to have a fixed SEED. By default, the systime is used....




    PReaction my_reaction("_P1 = 2.2","g","p","p eta' [dilepton [e+ e-] g]","etaP_Aphi",1,0,0,0);
    
    
    my_reaction.Loop(1500);
    
    
    
}
Re: eta prime dalitz [message #14860 is a reply to message #14859] Wed, 12 June 2013 08:18 Go to previous messageGo to next message
Ingo Froehlich is currently offline  Ingo Froehlich
Messages: 167
Registered: March 2004
Location: IKF - Frankfurt
first-grade participant
From: 109.46.234*
Hi,

the problem is known and will be corrected soon. The eta prime Dalitz decay is there in the physics class but missing in the data base. You have to add:

makeStaticData()->AddDecay(-1, "eta' -> g + dilepton", "eta'", "g,dilepton", 0.0009);

in the very beginning of your macro.


--
Ingo Froehlich
IKF - University of Frankfurt
069-798-47027, FAX: -47024
Re: eta prime dalitz [message #15354 is a reply to message #14859] Mon, 26 August 2013 00:03 Go to previous messageGo to next message
Michael Kunkel is currently offline  Michael Kunkel
Messages: 53
Registered: June 2011
continuous participant
From: *hr.hr.cox.net
Edit: Disregard, didnt have threshold set to an appropriate decimal.



Greetings,

When I apply the above prescription, I get the following warnings
Warning in <PHadronDecayM1::sampleM1>: not enough energy
Warning in <PHadronDecayM1::SampleMass>: failed in [g + p_m1_p_eta'], ecm=1.849045
Warning in <PChannel::Genbod>: No mass sampling model(s) found in g + p --> p + eta'


I do get a distribution and the codes exits successfully, I thought I would report it.

[Updated on: Mon, 26 August 2013 23:15]

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Re: eta prime dalitz [message #15370 is a reply to message #15354] Wed, 28 August 2013 11:51 Go to previous message
Ingo Froehlich is currently offline  Ingo Froehlich
Messages: 167
Registered: March 2004
Location: IKF - Frankfurt
first-grade participant
From: *dip0.t-ipconnect.de
This happens when the parent does not have sufficient energy (maybe due to the beam smearing?). Anyhow, the false events are resampled.

--
Ingo Froehlich
IKF - University of Frankfurt
069-798-47027, FAX: -47024
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