<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"></head><body>Hello all,<div><br></div><div> I just had a quick look to Hendrik's and Andy's mails.</div><div>I may come back to you with more questions in the coming days.</div><div><br></div><div>I just wanted here to thank you for your answers.</div><div><br></div><div>Have a nice day,</div><div> Antonin</div><div><br><br><span style="font-size:87%">Envoyé depuis un mobile Samsung</span> </div><br><br><br> a écrit : <br><br><br><div style="word-break:break-all;">Hi Antonin,<br><br>quoting a pdf is kind of awkward, so you'll have to live with numbered<br>answers:<br><br>A.1: UnstableFinalState returns all status==1 and status==2 particles,<br> minus duplicates, minus reggeons, minus decaying photons, minus<br> partons, minus zero-momentum particles. So yes, all particles you<br> mentioned will be seen by UnstableFinalState. And no, you can't<br> choose what you get. You get everything. If you want to select, you<br> need to use IdentifiedFinalState or VetoedFinalState.<br><br>A.2: Stable/unstable is set by the generator.<br><br>A.3: See A.1. You get all status==1 and status==2 particles.<br><br>A.4: See A.1. Yes. Mothers, daughters, sisters, the whole family.<br><br>B.1: The two analyses you quote ask very different questions, so<br> recommending one over the other would be like answering the<br> questions whether a VW Beatle or a television is better. If you<br> want to know whether a certain particle appears amongst the<br> ancestors, then ask for that particle (-> ALICE). If you want to<br> know if any B-hadron (and there are plenty!!!) appears amongst the<br> ancestors, then ask for that (-> ATLAS). It depends on your<br> application.<br><br>B.2: Ancestors are ancestors. As opposed to just parents. See<br> http://rivet.hepforge.org/code/hepmc/classHepMC_1_1GenVertex_1_1edge__iterator.html<br><br>C.1: Bins in histograms are automatically normalized for their bin<br> width. In a histogram (as opposed to a bar chart) the defining<br> quantity is the area of the bin, not its height.<br><br>C.2: The weight is supplied by the MC event generator. It might be the<br> same for all events, it might be a different weight for each event<br> (to make the generation more efficient (or possible at all!)). The<br> sumOfWeights() is the sum of weights of all events Rivet has seen.<br> Scaling by 1./sumOfWeights() means normalizing the histogram area<br> (if for example you had exactly one fill per event, the histogram<br> will be normalized to 1).<br><br>C.3: crossSection() is the cross-section value provided by the<br> generator and of course depends on the process. But it doesn't know<br> anything about your analysis. If you want to document your cut<br> flow, you have to do some bookkeeping yourself.<br><br>C.4: Yes, it is up to the user to define what NSD means. Because NSD is<br> not a physically meaningful definition. Cuts are. Triggers are. But<br> "NSD" is not.<br><br>D.1: The Multiplicity projection takes whatever particles you feed into<br> it and counts them for you. If, like in your "cnfs" example, you<br> feed it charged and neutral stable particles within -4 < |eta| < 4<br> and pT>2GeV, then it will count those. If you feed it something<br> else, well, it'll count that.<br><br>D.2: I'm sorry, I don't understand the question.<br><br>E.1: Yes. Read the generator manual on setting the random number seeds.<br> About combining the results, well, it depends on your observables.<br> Overall, yodamerge is a good starting point.<br><br>E.2: Yes. Read the generator manual.<br><br>E.3: Read the generator manual.<br><br>E.4: Read the generator manual and/or visit the MCnet school. All<br> generators come with examples, and all our previous schools used<br> the C++ generators in the tutorials, not the Fortran ones.<br><br>In August there will be the next MCnet school with lectures and several<br>hands-on tutorials on Rivet and the major MC event generators. The<br>generator authors and the Rivet authors will be present. This might be a<br>good opportunity to learn more about Monte Carlo, and probably answers<br>all your questions (certainly all the ones you asked in your mail). Note<br>that the registration deadline is soon -- if you miss it but still want<br>to go, contact the organisers:<br>http://www.montecarlonet.org/index.php?p=MCSchool/Gottingen<br><br>Cheers,<br><br> Hendrik<br><br>-- <br>If your dreams don't scare you, then you are not dreaming big enough.<br></div> </body>