2011 QCD and High Energy Interactions - Rencontres de Moriond ...

λ’
311
95% C.L.
0.014
0.012
0.01
0.008
0.006
0.004
0.002
-1
DØ, 5.3 fb -1
DØ, 5.3 fb
λ
λ
λ
λ
312
312
=0.07
=0.02
=0.01
312
=0.005
312
[GeV]
ντ ∼ M
0
100 150 200 250 300 350 400 450 500
3j + 3j) [pb]
→
p
BR(p
×
σ
5
10
4
10
3
10
2
10
10
2
2
0.5 TeV/c < m~
< 0.7 TeV/c
q
2
m~
=m~
+ 10 GeV/c
q g
-1
CDF RUN II Preliminary 3.2 fb
Observed 95% C.L. limit
Expected 95% C.L. limit
± 1σ
on expected limit
80 100 120 140 160 180 200 220 240
2
gluino mass [GeV/c ]
Figure 2: DØ cross section limit on the resonant sneutrino as a function of the sneutrino mass (left) and CDF
cross section limit on the gluino pair production as a function of the gluino mass (right).
fb −1 data sample analysed. The resulting 95% C.L. limit on the cross section led to exclude
sneutrino masses heavier than 300 GeV (Fig. 2, left).
4.2 Search for 3-jet resonances
The CDF experiment12 has performed a model independent search for 3-jet hadronic resonances.
Events with a high number of jets (at least six) and no E/T were selected. The dominant multijet
background was estimated from data using 5-jet events. To model new physics signatures that
could hide in the analyzed data sample corresponding to an integrated luminosity of 3.2 fb−1 ,
gluino pairs decaying each into three partons (through λ ′′
couplings) were chosen. Kinematic
quantities such as invariant mass and scalar pT sum of jet triplets (and their correlations) were
used to extract the signal. No significant excess of data has been observed and 95% C.L. limits
on the production cross section of the process ˜g˜g →3 jets+3 jets have been set: gluino masses
below 144 GeV have been excluded (Fig. 2, left).
5 Summary
This contribution reported the most recent results of searches for SUSY at the Tevatron. Analyses
performed by the CDF and DØ collaboration using up to 6.3 fb −1 of data were summarized.
No significant data excess has been observed and the results have been interpreted as 95% C.L.
exclusion limits on the free parameters of several SUSY scenarios.
References
1. See, for instance: H.P. Nilles, Phys. Rep. 110, 1 (1984).
2. V.M. Abazov et al, Phys. Lett. B 696, 321 (2011).
3. T. Aaltonen et al, Phys. Rev. Lett. 104, 251801 (2010).
4. V.M. Abazov et al, Phys. Lett. B 693, 95 (2010).
5. CDF public note 9817.
6. V.M. Abazov et al, Phys. Lett. B 680, 34 (2009).
7. V.M. Abazov et al, Phys. Rev. Lett. 105, 221802 (2010).
8. M. Strassler and K. Zurek, Phys. Lett. B 651, 374 (2007).
9. V.M. Abazov et al, Phys. Rev. Lett. 105, 211802 (2010).
10. For a review see: R. Barbier et al, Phys. Rep. 420, 1 (2005).
11. V.M. Abazov et al, Phys. Rev. Lett. 105, 191802 (2010).
12. CDF public note 10256.