scholarly journals Next-to-leading order QCD corrections to the top quark decay via the flavor-changing neutral-current operators with mixing effects

2010 ◽  
Vol 82 (7) ◽  
Author(s):  
Jia Jun Zhang ◽  
Chong Sheng Li ◽  
Jun Gao ◽  
Hua Xing Zhu ◽  
C.-P. Yuan ◽  
...  
Keyword(s):  
Top Quark ◽  
Neutral Current ◽  
Leading Order ◽  
Flavor Changing ◽  
Mixing Effects ◽  
Top Quark Decay ◽  
Flavor Changing Neutral Current ◽  
Quark Decay

scholarly journals NEXT-TO-NEXT-TO-LEADING ORDER SOFT AND VIRTUAL CORRECTIONS FOR QCD, HIGGS AND SUSY PROCESSES

2004 ◽  
Vol 19 (06) ◽  
pp. 405-419 ◽  
Author(s):  
NIKOLAOS KIDONAKIS
Keyword(s):  
Top Quark ◽  
W Boson ◽  
Neutral Current ◽  
Leading Order ◽  
Large Transverse Momentum ◽  
Hadron Colliders ◽  
Unified Approach ◽  
Anomalous Couplings ◽  
Flavor Changing ◽  
Flavor Changing Neutral Current

We review recent advances in the calculation of higher-order soft-gluon corrections for a variety of QCD, Higgs, and SUSY processes in hadron colliders. A unified approach and master formulas for next-to-next-to-leading order soft and virtual corrections are discussed. We present some applications of the formalism to top quark pair production at the Tevatron and the LHC, top production via anomalous couplings in flavor-changing neutral-current processes, W boson hadroproduction at large transverse momentum, and charged Higgs production at the LHC.

scholarly journals SCALAR DARK MATTER EFFECTS IN HIGGS AND TOP QUARK DECAYS

2007 ◽  
Vol 22 (25n28) ◽  
pp. 2121-2129 ◽  
Author(s):  
XIAO-GANG HE ◽  
HO-CHIN TSAI ◽  
TONG LI ◽  
XUE-QIAN LI
Keyword(s):  
Dark Matter ◽  
Top Quark ◽  
Neutral Current ◽  
Higgs Doublet ◽  
Tree Level ◽  
Flavor Changing ◽  
Higgs Decay ◽  
Dark Matter Relic Density ◽  
Flavor Changing Neutral Current ◽  
Two Higgs Doublet Model

We study possible observational effects of scalar dark matter, the darkon D, in Higgs h and top quark t decay processes, h → DD and t → cDD in the minimal Standard Model (SM) and its two Higgs doublet model (THDM) extension supplemented with a SM singlet darkon scalar field D. We find that the darkon D can have a mass in the range of sub-GeV to several tens of GeV, interesting for LHC and ILC colliders, to produce the required dark matter relic density. In the SM with a darkon, t → cDD only occurs at loop level giving a very small rate, while the rate for Higgs decay h → DD can be large. In THDM III with a darkon, where tree level flavor changing neutral current (FCNC) interaction exists, a sizable rate for t → cDD is also possible.

Search for Flavor-Changing Neutral Current Decays of the Top Quark inpp¯Collisions ats=1.8TeV

1998 ◽  
Vol 80 (12) ◽  
pp. 2525-2530 ◽  
Author(s):  
F. Abe ◽  
H. Akimoto ◽  
A. Akopian ◽  
M. G. Albrow ◽  
S. R. Amendolia ◽  
...  
Keyword(s):  
Top Quark ◽  
Neutral Current ◽  
Flavor Changing ◽  
Flavor Changing Neutral Current

scholarly journals Studying flavor-changing neutral tqZ couplings: Current constraints and future prospects

2019 ◽  
Vol 34 (34) ◽  
pp. 1950278 ◽  
Author(s):  
Zenrō Hioki ◽  
Kazumasa Ohkuma ◽  
Akira Uejima
Keyword(s):  
Top Quark ◽  
Neutral Current ◽  
Branching Fractions ◽  
Hadron Collider ◽  
Coupling Constants ◽  
Flavor Changing ◽  
Lagrangian Framework ◽  
Effective Lagrangian ◽  
Flavor Changing Neutral Current ◽  
Invariant Dimension

Possible nonstandard tuZ and tcZ interactions, which induce flavor-changing neutral-current decays of the top quark, are studied in the effective-Lagrangian framework. The corresponding Lagrangian consists of four kinds of nonstandard couplings coming from [Formula: see text] invariant dimension-6 effective operators. The four coupling constants in each interaction are treated as complex numbers independent of each other and constraints on them are derived by using the present experimental limits of the branching fractions for [Formula: see text] and [Formula: see text] processes. Future improvements of those constraints are also discussed as well as possibilities of measurements of these couplings at the High-Luminosity Large Hadron Collider.

Sign in / Sign up

Export Citation Format

Share Document