Compact Muon Solenoid
LHC, CERN
Visit us: CMS Public Website, CMS Physics ;
Contact us: CMS Publications Committee
| CMS-EXO-11-098 ; CERN-PH-EP-2012-251 | ||
| Combined search for the quarks of a sequential fourth generation | ||
| CMS Collaboration | ||
| 6 September 2012 | ||
| Phys. Rev. D 86 (2012) 112003 | ||
| Abstract: Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up- and down-type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant CKM matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. This result significantly reduces the allowed parameter space for a fourth generation of fermions. | ||
| Links: e-print arXiv:1209.1062 [hep-ex] (PDF) ; CDS record ; inSPIRE record ; Public twiki page ; CADI line (restricted) ; | ||
| Figures | |
png pdf |
Figure 1-a:
|
png pdf |
Figure 1-b:
|
png pdf |
Figure 1-c:
|
png pdf |
Figure 1-d:
|
png pdf |
Figure 2-a:
|
png pdf |
Figure 2-b:
|
|
|
Compact Muon Solenoid LHC, CERN |
|
|
|
|
|
|