<html> <head> <meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"> </head> <body text="#000000" bgcolor="#FFFFFF"> On 07/11/13 09:34, Ulla Blumenschein wrote: <blockquote cite="mid:CA+9n4GRLtRDU5hNncdW7F6kkRAwK893CsPU9tKyKfRoWvrqEhA@mail.gmail.com" type="cite"> <pre wrap="">Hi Andy, do you have a short technical outline for the new dressing implementation (e.g. a list of pid mothers to exclude?) Since there seems to be no one else willing to do this, I fear I have to make a comparison with the old definition myself and sell it to SM... </pre> </blockquote> Hi Ulla, not sure if it helps much but these are PDGIds I currently use to reject photons of tau and hadron decays: <blockquote>int hadronsandtaus[73] = {15, 111, 113, 115, 211, 213, 215, 221, 223, 225, 313, 315, 323, 325, 331, 333, 411, 413, 421, 423, 425, 431, 433, 511, 513, 521, 523, 531, 533, 551, 1114, 2103, 2114, 2203, 2212, 2214, 2224, 3114, 3212, 3324, 4132, 4312, 4322, 5122, 5312, 5322, 10213, 10221, 10223, 10311, 10313, 10321, 10323, 10333, 10411, 10423, 10433, 12112, 12212, 13222, 20113, 20213, 20223, 20313, 20323, 20413, 20423, 20433, 23122, 100443, 9000111, 9000211, 9010221}; </blockquote> This list is based on a study where I looked at Sherpa 1.3.1 samples, both ee and mumu, and checked what motherPDGids do photons (status=1) have that fall into the dressing cone of 0.1. I was lazy and used the absolute values of the pdgids. Not sure if this list is complete, what I found though as that the variety of photonic hadron decays is much larger in Sherpa than it is in Pythia, which, according to Marek Schönherr, is due to the hadron decay module in sherpa using full multiplets which Pythia8 does not. E.g. you won't find any photonic a_0 decays in Pythia8. Cheers, Holger <blockquote cite="mid:CA+9n4GRLtRDU5hNncdW7F6kkRAwK893CsPU9tKyKfRoWvrqEhA@mail.gmail.com" type="cite"> <pre wrap=""> Many thanks in advance, Ulla On Thu, Oct 3, 2013 at 3:16 PM, Andy Buckley <a class="moz-txt-link-rfc2396E" href="mailto:andy.buckley@cern.ch"><andy.buckley@cern.ch></a> wrote: </pre> <blockquote type="cite"> <pre wrap="">Hi Ulla, all, I've discussed this a bit with Daniel Froidevaux and think that it would make sense for us to at least add a flag to the ClusteredPhotons tool in Rivet to exclude photons which come from hadron decays. Taus are a bit of a borderline case, but that does not affect (current) EW measurements. This is not *exactly* the same definition, but I think that "only photons from W/Z" is hard to implement in a generator-unspecific way. Maybe Frank Siegert wants to comment more on this proposal to use the fromDecay() function in ClusteredPhotons, since he did most of the detailed work to put these W/ZFinders and related classes together. Re. the Born comparisons, I believe that the ATLAS W/Z analyses written so far *don't* compare to the Born-level results, since there *isn't* a generator-portable way to write them. I remember removing a generator-specific code along those lines in a previously submitted analysis for that reason: it's fine for ATLAS-internal versions of analyses but won't go into the public Rivet library. Hope that helps, Andy PS. For those who care, if we agree that that is a reasonable route, I propose that the exclude-decay-photons functionality would go into Rivet 2.0.1 or 2.0.2. The exact version depends on the extent to which we want to separate different types of change -- 2.0.1 might just be adding some "queued" analysis codes, or it could be a combination of that and some definition changes. The numbering does not really reflect anything about the timescales! But note that we'll only be making this change in the Rivet 2 series -- 1.x is in "maintenance mode". On 03/10/13 14:51, Roman Lysak wrote: </pre> <blockquote type="cite"> <pre wrap=""> Hi Ulla, I think the Rivet authors are better to replay to your questions so I'm cc-ing this to them. Could anyone address Ulla's questions? Cheers, Roman On 10/03/2013 12:25 PM, Ulla Blumenschein wrote: </pre> <blockquote type="cite"> <pre wrap="">Hi Roman, we have currently a discussion in SM about how to synchronize the Atlas internal definition of dressed leptons with the Rivet implementation. Currently in SM, we sum all photons emitted from the W/Z decay products whereas Rivet sums all photons. With the extreme phase spaces which we access with 8TeV there are differences up to percentage level between these definitions due to pi0 decays from hadronic activity close to leptons. Is it possible to implemet an alternate Z finder which can discriminate photon sources? I understand that this might be against the philosophy of Rivet (MC independence). Or are there other problems? Also the born level Z finder is not completely clear to me. I assumed so far that the born level is defined by different status codes in different MC generator, so how does Rivet handle this issue? Many thanks in advance, Ulla On Sun, Sep 15, 2013 at 7:46 PM, Roman Lysak <a class="moz-txt-link-rfc2396E" href="mailto:lysak@fzu.cz"><lysak@fzu.cz></a> wrote: </pre> <blockquote type="cite"> <pre wrap=""> Hi Ulla, On 09/12/2013 06:51 PM, Ulla Blumenschein wrote: </pre> <blockquote type="cite"> <pre wrap="">Hi Roman, Could you explain how we define Born and dressed in a generator independent way in Rivet? </pre> </blockquote> <pre wrap=""> it depends on the object type. For example, for Z boson (similarly for W boson), you can specify whether to add photons (next to last one parameter in the constructor below) in a given radius (2nd next to last one parameter) around the leptons from Z decay to the Z boson 4-momentum. //fiducial phase space + born level ZFinder zfinder_mu(-2.4, 2.4, 20, MUON, 66.0*GeV, 116.0*GeV, 0.1, false, false); addProjection(zfinder_mu, "ZFinder_mu"); //for combined cross-sections (combined phase space + dressed level) ZFinder zfinder_comb_mu(-2.5, 2.5, 20, MUON, 66.0*GeV, 116.0*GeV, 0.1, true, false); Sorry for late response. Cheers, Roman </pre> <blockquote type="cite"> <pre wrap="">Cheers, Ulla /_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ Ulla Blumenschein II Physik, Uni Goettingen Friedrich-Hund-Platz 1, D01.110 phone: 0049-551-397645 /_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ </pre> </blockquote> <pre wrap=""> </pre> </blockquote> <pre wrap=""> </pre> </blockquote> <pre wrap=""> _______________________________________________ Rivet mailing list <a class="moz-txt-link-abbreviated" href="mailto:Rivet@projects.hepforge.org">Rivet@projects.hepforge.org</a> <a class="moz-txt-link-freetext" href="http://www.hepforge.org/lists/listinfo/rivet">http://www.hepforge.org/lists/listinfo/rivet</a> </pre> </blockquote> <pre wrap=""> -- Dr Andy Buckley, Royal Society University Research Fellow Particle Physics Expt Group, University of Glasgow / PH Dept, CERN </pre> </blockquote> <pre wrap=""> </pre> </blockquote> </body> </html>