Related papers: Sigma meson resonance and its coupling constant
We study the Higgs-boson mass spectrum of a classical scale-invariant realization of the two-Higgs-doublet model (SI-2HDM). The classical scale symmetry of the theory is explicitly broken by quantum loop effects due to gauge interactions,…
In the presence of non-minimal gravitational coupling $ \xi H^\dagger H {\cal R}$ between the standard model (SM) Higgs doublet $H$ and the curvature scalar ${\cal R}$, the effective ultraviolet cutoff scale is given by $\Lambda_{\rm…
In this talk I summarize recently proposed mechanisms to understand pi pi scattering to 1 GeV in an effective chiral Lagrangian. The Lagrangian includes higher resonances in addition to pions consistently with the chiral symmetry. Iso-spin…
A lepton collider in the multi-TeV range has the potential to measure the trilinear Higgs self-coupling constant $\lambda_{hhh}$ via the W-fusion mode $\ell^+\ell^- \rightarrow \nu_\ell \bar{\nu}_\ell h h$. In this paper we do a…
By fitting the R values between 3.7 and 5.0 GeV measured by the BES collaboration, the upper limit of the electron width of the newly discovered resonance Y(4260) is determined to be 580 eV at 90% C.L. Together with the BABAR measurement on…
Using the LHC and Tevatron data, we set upper and lower limits on the total width of the Higgs-like boson. The upper limit is based on the well-motivated assumption that the Higgs coupling to a W or Z pair is not much larger than in the…
The light mesons such as pi, rho, omega, f0, and a0 are possible candidates of magnetic degrees of freedom, if a magnetic dual picture of QCD exists. We construct a linear sigma model to describe spontaneous breaking of the magnetic gauge…
A recent ATLAS search for diboson resonances and a CMS search for $eejj$ resonances which both show excesses with significance around 3 sigma have generated interest in $SU(2)_R$ gauge extensions of the Standard Model with a $W'$ mass…
We apply the perturbative chiral quark model (PCQM) at one loop to analyse meson-baryon sigma-terms. Analytic expressions for these quantities are obtained in terms of fundamental parameters of low-energy pion-nucleon physics (weak pion…
The structure of the $\sigma$ meson and the diamagnetism of the nucleon are shown to be topics which are closely related to each other. Arguments are found that the $\sigma$ meson couples to two photons via its non-strange $q\bar{q}$…
The cross section of the process $e^{+}e^{-}\to\omega\pi^{0}\pi^{0}$ is measured at nineteen center-of-mass energies from 2.0 to 3.08 GeV using data collected with the BESIII detector at the BEPCII storage ring. A resonant structure around…
In certain five dimensional gauge theories the Standard Model Higgs doublet is identified, after compactification on the orbifold S^1/Z_2, with the zero mode of the fifth component of the gauge field. An effective potential for the Higgs…
We study the structure of the sigma meson, the lowest-lying resonance of the pi pi scattering in the scalar-isoscalar channel, through the softening phenomena associated with the partial restoration of chiral symmetry. We build dynamical…
An enhancement near the m_p + M_{\Lambda} mass threshold is observed in the combined p \bar{\Lambda} and \bar{p}\Lambda invariant mass spectrum from J/\psi --> p K^- \bar{Lambda} + c.c. decays. It can be fit with an S-wave Breit-Wigner…
The pi0 pi0 mass spectra and angular distributions around KK_bar-threshold and at 1.5 GeV in pp_bar(at rest) to 3pi0 in the Crystal Barrel experiment are reanalyzed by applying the new method, which is consistent with unitarity of S-matrix…
We use a nonpertubative approach which combines coupled channel Lippmann Schwinger equations with meson-meson potentials provided by the lowest order chiral Lagrangian. By means of one parameter, a cut off in the momentum of the loop…
We show that if the Standard Model gauge fields and fermions propagate in extra dimenions, a composite Higgs field with the correct quantum number can arise naturally as a bound state due to the strong gauge interactions in higher…
We perform a comprehensive statistical analysis of the standard model (SM) with three and four generations using the latest Higgs search results from LHC and Tevatron, the electroweak precision observables (EWPOs) measured at LEP and SLD…
Spontaneous symmetry breaking through the Higgs field has been experimentally confirmed as a basic ingredient of the Standard Model. However, the origin of the phenomenon may not be entirely clear, because, in perturbation theory, the…
We tested several models in which the Standard Model (SM) gauge group is extended by an additional U(1) gauge symmetry, against available electroweak precision data to impose limits on the mass of the neutral Z' boson, M_Z', predicted in…