arXiv subjects

A. Likhoded

Publications and source records attributed to A. Likhoded.

5 recordsLinked to original sources

arXiv2004

Constraints on a scalar-pseudoscalar Higgs mixing at future e+e- colliders: an update

We perform an update of our previous analysis on the constraints on possible deviations of Hbb coupling from its Standard Model value, arising from a scalar-pseudoscalar mixing. In this paper we include a complete simulation of the process e+ e- -> b bbar e+ e- and combine it with our previous results to obtain tighter bounds on the deviations of the parameters describing this coupling that could be measured at the Next Linear Collider.

hep-ph↗

arXiv2002

Future e^+ e^- Colliders Sensitivity to H b b-bar Coupling and CP Violation

We perform a complete simulation of the process e^+ e^- --> b b-bar nu nu-bar, where nu can be an electron, muon or tau neutrino, in the context of a general Higgs coupling to b quarks. We parametrize the H b b-bar coupling as m_b/v (a + i gamma_5 b). Taking into account interference effects between pure Higgs and Standard Model contributions, we find that sensitivities of the order of 2% and 20% can be obtained at a future e^+ e^- collider for deviations of the $a$ and $b$ parameters respectively from their Standard Model values. Combining our analysis with an independent measurement of Gamma_{H --> b b-bar} can provide evidence about the CP nature of the Higgs sector.

hep-ph↗

arXiv2002

Measuring Higgs Coupling to Tau-Leptons at Future e+ e- Colliders

We perform a complete simulation of the process $ e^+ e^- \to τ^+ τ^- ν\barν$, where $ν$ can be an electron, muon or tau neutrino, in the context of a general Higgs coupling to $τ$ leptons. We analyse various kinematical distributions and obtain the sensitivity regions in the parameter space that can be explored at a future $e^+ e^-$ collider. In particular, inclusion of $W$ boson fusion enhances the sensitivity significantly.

hep-ph↗

arXiv2000

Top-quark couplings to TeV resonances at future lepton colliders

We study the processes $W_L W_L \to t \bar t$ and $W_L Z_L \to t\bar b (\bar t b)$ at future lepton colliders as probes of the couplings of the top quark to resonances at the TeV scale. We consider the cases in which the dominant low energy feature of a strongly interacting electroweak symmetry breaking sector is either a scalar or a vector resonance with mass near 1 TeV. We find that future lepton colliders with high energy and high luminosity have great potential to sensitively probe these physics scenarios. In particular, at a 1.5 TeV linear collider with an integrated luminosity of 200 fb$^{-1}$, we expect about 120 events for either a scalar or a vector to decay to $t\bar t, t \bar b$. Their leading partial decay widths, which characterize the coupling strengths, can be statistically determined to about 10% level.

hep-ph↗

arXiv1996

Probing Quartic Couplings Through Three Gauge Boson Production at an $e^+e^-$ Linear Collider

We explore the capability of a 500 or 1000 GeV $e^+e^-$ linear collider to measure anomalous quartic gauge boson couplings. In the framework of a non-linear effective Lagrangian with a custodial $SU)2)$ symmetry, there are only two next-to-leading order operators which contribute to quartic, but not to two- and three- gauge boson interactions. The limits on the coefficients of these operators from present and future $e^+e^-$ colliders are compared with those available from other sources.

hep-ph↗