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);


    PReaction my_reaction("_P1 = 2.2","g","p","p eta [dilepton [e+ e-] g]",creater,1,0,0,0);