ViewVC Help
View File | Revision Log | Show Annotations | Root Listing
root/cvsroot/UserCode/benhoob/cmsnotes/ZMet2012/introduction.tex
(Generate patch)

Comparing UserCode/benhoob/cmsnotes/ZMet2012/introduction.tex (file contents):
Revision 1.2 by benhoob, Mon Jun 25 11:45:56 2012 UTC vs.
Revision 1.4 by benhoob, Wed Jun 27 16:38:31 2012 UTC

# Line 8 | Line 8 | The search is based on a data sample of
8   corresponding to an integrated luminosity of \lumi.
9  
10   The production of Z bosons is expected in many BSM scenarios, for example supersymmetric (SUSY)
11 < models. For example, Z bosons may be produced in the decays $\chi^0_2\to Z \chi^0_1$
12 < $\chi^0_1\to Z \tilde{G}$, where $\chi^0_2$ is the second lightest neutralino, $\chi^0_1$ is
13 < the lightest neutralino, and $\tilde{G}$ is the gravitino. Such decays may occur in the cascade
11 > models. In SUSY models with neutralino lightest SUSY particle (LSP), Z bosons may be produced in the decays $\chi^0_2\to Z \chi^0_1$,
12 > where $\chi^0_2$ is the second lightest neutralino and $\chi^0_1$ is
13 > the lightest neutralino.
14 > In models with gravitino LSP such as gauge-mediated SUSY breaking (GMSB) models, Z bosons may be produced via
15 > $\chi^0_1\to Z \tilde{G}$, where $\tilde{G}$ is the gravitino. Such decays may occur either in the cascade
16   decays of the strongly-produced squarks and gluinos, or via direct production of the electroweak
17   charginos and neutralino. Examples of such processes (see Fig.~\ref{fig:diagrams}) are:
18  
# Line 36 | Line 38 | via direct production of the weakly-coup
38  
39   We thus pursue two strategies. The first is an inclusive strategy which selects events with a Z$\to\ell\ell$ candidate,
40   at least two jets, and large \MET. This strategy is useful for targeting, e.g., the production of Z bosons in the
41 < cascades decays of strongly-interacting particles as depicted in Fig.~\ref{fig:diagrams} (left). In the second strategy,
41 > cascade decays of strongly-interacting particles as depicted in Fig.~\ref{fig:diagrams} (left). In the second strategy,
42   we impose additional requirements which strongly suppress the backgrounds while retaining high efficiency for events
43 < with Z bosons produced via direct production of the weakly-coupled charginos and neutralinos. These two strategies
44 < are referred to as the ``inclusive search'' and the ``targeted search,'' respectively.
43 > with Z bosons produced via direct production of the weakly-coupled charginos and neutralinos.
44 > These two strategies are referred to as the ``inclusive search'' and the ``targeted search,'' respectively.
45  
46   After selecting events with jets and a $\Z\to\ell^+\ell^-$ ($\ell=e,\mu$) candidate,
47   the dominant background consists of SM \Z production accompanied by jets from initial-state radiation (\zjets).
# Line 51 | Line 53 | to establish that a potential excess is
53   \MET\ from jet mismeasurements. In this note, the \zjets\ background is estimated with the \MET templates technique,
54   in which the artificial \MET in \zjets events is modeled using a \gjets control sample.
55   The second background category consists of processes which produce leptons with uncorrelated flavor.
56 < These ``flavor-symmetric'' (FS) backgrounds, which are dominated by \ttbar but also contain WW, DY$\to\tau\tau$
56 > These ``flavor-symmetric'' (FS) backgrounds, which are dominated by \ttbar\ but also contain WW, DY$\to\tau\tau$
57   and single top processes, are estimated using a data control sample of e$\mu$ events.
58   Additional backgrounds from WZ and ZZ production are estimated from MC, after validation of the MC modeling
59   of these processes using 3-lepton and 4-lepton data control samples.

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines