scholarly journals Flavor-changing neutral current in production and decay of pseudoscalar mesons in a type III two-Higgs-doublet-model with four-texture Yukawa couplings

2009 ◽  
Vol 80 (5) ◽  
Author(s):  
M. Gómez-Bock ◽  
G. López-Castro ◽  
L. López-Lozano ◽  
A. Rosado
2014 ◽  
Vol 29 (18) ◽  
pp. 1450085
Author(s):  
Andrés Castillo ◽  
Rodolfo A. Diaz ◽  
Jhon Morales

Unitarity constraints for Yukawa couplings are considered in the Two-Higgs-Doublet Model type III, by using a general expansion in partial waves for fermionic scattering processes. Constraints over general Flavor Changing Neutral Currents are found from that systematic, wherein such bounds compete with those coming from Lagrangian perturbativity requirement but are weaker than those imposed from phenomenological processes and precision tests. Nevertheless, for bounds based on unitarity, the number of assumptions is the lowest among phenomenological and theoretical limits. Indeed, these new theoretical constraints are independent of scalar masses or mixing angles for this extended Higgs sector, making them less model dependent.


2007 ◽  
Vol 22 (25n28) ◽  
pp. 2121-2129 ◽  
Author(s):  
XIAO-GANG HE ◽  
HO-CHIN TSAI ◽  
TONG LI ◽  
XUE-QIAN LI

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.


2008 ◽  
Author(s):  
J. H. Montes de Oca Y. ◽  
S. R. Juárez W. ◽  
P. Kielanowski ◽  
Heriberto Castilla-Valdez ◽  
Omar Miranda ◽  
...  

2011 ◽  
Author(s):  
D. Morales C. ◽  
S. R. Juárez W. ◽  
P. Kielanowski ◽  
Alejandro Ayala ◽  
Guillermo Contreras ◽  
...  

2011 ◽  
Vol 26 (25) ◽  
pp. 1869-1879 ◽  
Author(s):  
H. CARDENAS ◽  
J. DUARTE ◽  
J. ALEXIS RODRIGUEZ

The D0 experiment has reported a direct search for a charged Higgs boson produced by [Formula: see text] annihilation and decaying to [Formula: see text] final state, in the 180≤MH+≤300 GeV mass range. The analysis has led to upper limits on the production cross-section in the framework of the two-Higgs doublet model types I, II and III. We compare the predictions of two different scenarios in the framework of the two-Higgs doublet type III to the cross-section limits reported by D0 collaboration, and we obtain constraints on the charged Higgs mass, for the case when the charged Higgs mass is bigger than the top quark mass. Also, searches for the charged Higgs boson with a mass smaller than top quark mass are considered, we discuss the possible limits on the charged Higgs boson mass obtained from measurements of the ratio [Formula: see text] within the two-Higgs doublet model type III.


2013 ◽  
Vol 28 (25) ◽  
pp. 1350124 ◽  
Author(s):  
R. GAITÁN ◽  
E. A. GARCES ◽  
O. G. MIRANDA ◽  
J. H. MONTES DE OCA Y

Many extensions to the Standard Model imply the existence of new charged scalar Higgs bosons. We study the contribution of a general scalar or pseudoscalar coupling for the neutrino–electron scattering. We take a phenomenological approach in order to obtain model independent limits to the couplings that arise in this picture. We illustrate the reach of the constraints by studying the particular case of the type III two Higgs doublet model, where we have found new constraints to some elements of the Yukawa couplings mixing matrix (|Yee| ≤ 1 × 10-1 and |Yeμ| ≤ 7 × 10-2 at 90% CL).


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