Search of anomalous $Wtb$ couplins in single top quark prodution at D0

Conference · Thu Dec 01 04:00:00 EST 2011 · Submitted to Pramana

OSTI ID:1039345

Joshi, Jyoti; Beri, Suman

The large mass of the top quark, close to the electroweak symmetry-breaking scale, makes it a good candidate for probing physics beyond the Standard Model, including possible anomalous couplings. D0 has made measurements of single top quark production using 5.4 fb{sup -1} of integrated luminosity. We examine the data to study the Lorentz structure of the Wtb coupling. We find that the data prefer the left-handed vector coupling and set upper limits on the anomalous couplings. In 2009, the electroweak single top quark production was observed by the D0 and CDF collaborations. Electroweak production of top quarks at the Tevatron proceeds mainly via the decay of a time-like virtual W boson accompanied by a bottom quark in the s-channel (tb = t{bar b} + {bar t}b), or via the exchange of a space-like virtual W boson between a light quark and a bottom quark in the t-channel (tqb = tq{bar b} + {bar t}qb, where q refers to the light quark). For a top quark mass of 172.5 GeV, The Standard Model (SM) prediction of single top production rate at next-to-leading order with soft-gluon contributions at next-to-next-to-leading order are 1.04 {+-} 0.04 pb (s-channel) and 2.26 {+-} 0.12 pb (t-channel). The large mass of the top quark implies that it has large couplings to the electroweak symmetry breaking sector of the SM and may have non-standard interactions with the weak gauge bosons. Single top quark production provides a unique probe to study the interactions of the top quark with the W boson.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL
• Sponsoring Organization: DOE Office of Science
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 1039345
• Report Number(s): FERMILAB-CONF-11-648-E
• Conference Information: Journal Name: Submitted to Pramana
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
Accelerators
BOSONS
DECAY
FERMILAB COLLIDER DETECTOR
FERMILAB TEVATRON
FORECASTING
INTERMEDIATE BOSONS
LEPTONS
LUMINOSITY
PHOTONS
PHYSICS
PROBES
PRODUCTION
QUARKS
S CHANNEL
STANDARD MODEL
SYMMETRY BREAKING
T CHANNEL
T QUARKS
VECTORS