Activities in the SUSY sector
@ HEPHY / Vienna
Wolfgang Adam for the CMS analysis group
June 29, 2010
Overview
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SUSY search in events with 1 lepton + jets + MET (RA4)
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SUSY search in events with 3rd generation quarks
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relatively new topic with a reach beyond SUSY
Non-SUSY activities in CMS physics
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low activity in the past years; plan to restart with
sufficient manpower
Interpretation of search results in terms of OSETs
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currently our main SUSY topic
QCD – quarkonium production
b-tagging
WA; IPM-HEPHY meeting June 29, 2010
SUSY / RA4
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Data-driven background estimation using the
“ABCD” method and extensions
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one possible choice: mT vs. MET
8-fields, “Rubik’s method”: correction for correlations
Measure correlations in
background dominated region
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Additional signal suppression:
$
!
3
"
#
Introduce cuts on a 3rd variable
to reduce signal in control region
G. Kasieczka, R. Schöfbeck,
W. Waltenberger
WA; IPM-HEPHY meeting June 29, 2010
SUSY / RA4
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Tests with other variables
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aim to avoid substantial correlation between mT and MET:
use HT-2 and MET significance
Compatible with two independent,
exponentially distributed variables
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included studies of systematics
R. Schöfbeck
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WA; IPM-HEPHY meeting June 29, 2010
SUSY / RA4
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Muon reconstruction for RA4
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efficiency of different components from data
based on reconstructed J/Psi’s and Upsilons
Comparison of pT and η distributions with LM1
W. Kiesenhofer, R. Schöfbeck
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WA; IPM-HEPHY meeting June 29, 2010
SUSY / RA4
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Determination of efficiencies with T&P
ID efficiency (track -> global muon)
Main difference: isolation
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WA; IPM-HEPHY meeting June 29, 2010
3rd generation in SUSY events
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Interested in b’s and t’s in SUSY candidate events
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Prototype study @ PTDR time
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search for an exclusive signature using a Z as a tag
clearly a high luminosity scenario
in the recent past continued as part of a PhD
project; introducing data-driven techniques
Z efficiencies via T&P
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V. Ghete, N. Hörmann, J. Strauss
WA; IPM-HEPHY meeting June 29, 2010
3rd generation in SUSY events
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Plan: restart top analysis in a more inclusive way
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attractive as a first step beyond the RA* analyses
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importance of the 3rd generation in distinguishing different scenarios
rapid commissioning of b-tag algorithms
(and corresponding expertise at HEPHY)
Possible area of collaboration IPM-HEPHY
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and using more manpower
potential to cover a wider range of scenarii by sharing
different parts of the analysis
WA; IPM-HEPHY meeting June 29, 2010
OSETs
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Attempt to avoid the dependence on constrained models with
limited theoretical justification
Description of new physics in terms of on-shell effective
theories
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Two main goals
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can be inspired by SUSY models
tuning of selections in terms of mass hierarchies
model-independent interpretation of results
Working on leptonic signatures
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in collaboration with UCSB and theorists
W. Waltenberger
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WA; IPM-HEPHY meeting June 29, 2010
OSETs
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Examples of OSET templates
LLM
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LLM1
WA; IPM-HEPHY meeting June 29, 2010
OSETs
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comparison of LLM1 with LM1 distributions
pT lepton
MET
HT
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WA; IPM-HEPHY meeting June 29, 2010
Other physics activities
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Quarkonium production
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relatively new topic – in collaboration with CERN and LIP
first steps: implementation of a specific HLT for low pT J/Psi’s
Will become the
main trigger for
low pT J/Psi’s once
the lowest pT muon
triggers will be prescaled
F. Teischinger,V.Knünz,
J.Strauss, H.Rohringer
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WA; IPM-HEPHY meeting June 29, 2010
Other physics activities
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b-tagging
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commissioning proceeds much faster than anticipated
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currently recommending simple tagging algorithms but
will turn attention to combined taggers in a few months time
Track IP
significance
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Sec. vertex
flight distance
currently assuming co-ordination role +
working on data-driven techniques for
SV efficiency measurement
C.Thomay, D.Liko,
W.Adam
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WA; IPM-HEPHY meeting June 29, 2010
Conclusions
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SUSY
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currently focussed on the inclusive single-lepton search (RA4)
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will put more attention on the next stage
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background estimates, muon efficiencies
interested in analysis of final states involving b’s and t’s
in both areas a collaboration could be fruitful for both parties
interesting topic at the border of SUSY: OSETs
SM and physics objects
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quarkonia analysis as complement to searches
involvement in b-tagging
WA; IPM-HEPHY meeting June 29, 2010