Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

ZZ event

  1. Nov 18, 2007 #1
  2. jcsd
  3. Nov 20, 2007 #2

    ahrkron

    User Avatar
    Staff Emeritus
    Gold Member

    I don't know the details of CDF electron identification, but I assume electrons are id'd based on calorimeter depositions, while muons depend on the muon chambers. If so, then the extra "debris" from the ppbar collision could have deposited enough energy in the calorimeter to pass the electron id. It is also possible that they are using this candidate even when one muon did not leave hits on the muon chambers (maybe went through a region without detector elements), in an attempt to increase the number of candidates on their sample.
     
  4. Nov 21, 2007 #3
    Probably they label it e/mu because it is consistent both with the electron hypothesis (since it leaves some energy in the electromagnetic calorimeter, see the purple block) and with the muon hypothesis (since it has hits in the muon chambers).

    My 2 cents: it is a muon which by chance is superimposed to a jet(*). There are three quite stiff tracks pointing in the same directions, which could justify the presence of a signal in the hadronic calorimeter (see the blue block over the purple block), and if it is a jet it's probable that you also have some neutral pions; neutral pions don't leave tracks but they decay into photons, and so give signal in the electromagnetic calorimeter.

    (*) or maybe a jet from the fragmentation of a b quark, with the B meson decaying muonically. In this case this event would belong to the background and not to the signal.
     
    Last edited: Nov 21, 2007
  5. Nov 21, 2007 #4
    ops, I essentially repeated the answer by ahrkron.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: ZZ event
  1. ZZ found at LHC (Replies: 1)

  2. CERN Zen Events - 1985 (Replies: 0)

  3. Coincidence events (Replies: 1)

Loading...