Related papers: Sigma meson resonance and its coupling constant
We first review the recent accumulating evidences of the existence of a scalar-isoscalar meson with the mass 500 to 800 MeV which may be identified with the sigma meson as the quantum fluctuation of the amplitude of the chiral order…
A distinct peak is observed in the pi^+/- psi' invariant mass distribution near 4.43 GeV in B->K pi^+/- psi' decays. A fit using a Breit Wigner resonance shape yields a peak mass and width of 4433+-4(stat)+-2(syst) MeV and Gamma =…
Based on the one-boson-exchange framework that the $\sigma$ meson serves as an effective parameterization for the correlated scalar-isoscalar $\pi\pi$ interaction, we calculate the coupling constants of the $\sigma$ to the $\frac{1}{2}^+$…
The effective potential of massless standard model (SM) is calculated up to three-loop order. The stability of the effective potential and the Higgs boson mass are investigated up to three-loop order. We found that, Higgs boson mass $m_{H}$…
Chiral Ward identities lead to consistent accounting for the sigma's width in the linear sigma model's Feynman rules. Reanalysis of pion scattering data at threshold imply a mass for the sigma of 600+ 200 - 100 MeV.
CERN measurements of pi(-)p->pi(-)pi(+)n on polarized target at 17.2 GeV/c enable experimental determination of partial wave production amplitudes below 1080 MeV. The measured S-wave transversity amplitudes provide evidence for a narrow…
We describe the meson-meson data for the ($IJ^{PC}=00^{++}$) wave at $280\leq\sqrt s\leq 1900$ MeV in two approaches: (i) the K-matrix approach and (ii) the dispersion relation D-matrix method. With a good description of low energy data (at…
We present results of an exclusive measurement of the first excited state of the Sigma hyperon, Sigma(1385)^+, produced in p+p -> Sigma^+ + K^+ + n at 3.5 GeV beam energy. The extracted data allow to study in detail the invariant mass…
BES data on the sigma pole are refitted taking into account new information on coupling of sigma to KK and eta-eta. The fit also includes Cern-Munich data on pi-pi elastic phases shifts and Ke4 data, and gives a pole position of 500 +- 30 -…
A separable potential model of three coupled channels (pion-pion, kaon-antikaon and an effective four pion) has been constructed and applied in the analysis of the isoscalar S-wave pion-pion and kaon-antikaon phase shifts and inelasticities…
Unification at M_{GUT}\sim 3\times 10^{16} GeV of the three Standard Model (SM) gauge couplings can be achieved by postulating the existence of a pair of vectorlike fermions carrying SM charges and masses of order 300 GeV -- 1 TeV. The…
Highly precise measurements of the $^{99}$Tc beta spectrum were performed in two laboratories using metallic magnetic calorimeters. Independent sample preparations, evaluation methods and analyses yield consistent results and the spectrum…
Resonance pole positions of the $f_0(500)$ alias $\sigma(500)$ meson are computed and plotted as a continuous function of pion mass in the framework of a unitary and analytic coupled-channel model for scalar mesons as dynamical $q\bar{q}$…
We compute a unitarity bound for higgs mass using one--loop corrected s--wave partial amplitude for $Z_L Z_L \rightarrow Z_L Z_L$ scattering. We use the equivalence theorem and show that the higgs mass has to be less than $\approx 600$ GeV…
We discuss the lower Higgs boson mass bounds which come from the absolute stability of the Standard Model (SM) vacuum and from the Higgs inflation, as well as the prediction of the Higgs boson mass coming from asymptotic safety of the SM.…
The latest measurements of the atomic level width in Sigma-hyperonic Pb atom offer the most accurate datum in the region of low-energy Sigma-hyperon physics. Atomic widths are due to the conversion of Sigma-nucleon into Lambda-nucleon. In…
Masses and widths of the four light scalar mesons $\sigma$, $\kappa$, $a_0$(980) and $f_0$(980) may be reproduced in a model where mesons scatter via a $q\bar{q}$ loop. A transition potential is used to couple mesons to $q\bar{q}$ at a…
The lightest QCD resonance, the sigma, has been recently fixed in the pi-pi scattering amplitude. The nature of this state remains nowadays one of the most intriguing and difficult issues in particle physics. Its coupling to photons is…
The assumption that the ratio of the Higgs self-coupling to the square of its yukawa coupling to the top is (almost) independent of the renormalization scale fixes the Higgs mass within narrow limits at m=160 GeV using only the values of…
It has been recently proposed that, besides the known resonance with mass $m_h\sim$ 125 GeV, the Higgs field could exhibit a new excitation with a larger mass $M_h$ related by $M^2_h\sim m^2_h \ln (\Lambda_s/M_h)$, where $\Lambda_s$ is the…