We are exploring a generic strongly-interacting Electroweak Symmetry Breaking Sector(EWSBS) with the low-energy effective field theory for the four experimentally known particles(W_L~±,Z_l,h) and its dispersion-relation based unitary extension.In this contribution we provide simple estimates for the production cross-section of pairs of the EWSBS bosons and their resonances at proton-proton colliders as well as in a future e^-e^+(or potentially aμ^-μ^+) collider with a typical few-TeV energy.We examine the simplest production mechanisms,tree-level production through a W(dominant when quantum numbers allow) and the simple effective boson approximation(in which the electroweak bosons are considered as collinear partons of the colliding fermions).We exemplify with custodial isovector and isotensor resonances at 2 TeV,the energy currently being discussed because of a slight excess in the ATLAS 2-jet data.We find it hard,though not unthinkable,to ascribe this excess to one of these W_lW_l rescattering resonances.An isovector resonance could be produced at a rate smaller than,but close to earlier CMS exclusion bounds,depending on the parameters of the effective theory.The ZZ excess is then problematic and requires additional physics(such as an additional scalar resonance).The isotensor one(that would describe all charge combinations) has smaller cross-section.
We confirm our previous prediction of a d* state with I(JP) = 0(3+) [Phys. Rev. C 60, 045203(1999)] and report for the first time based on a microscopic calculation that d* has about 2/3 hidden color(CC)configurations and thus is a hexaquark-dominated exotic state. By performing a more elaborate dynamical coupledchannels investigation of the △△-CC system within the framework of the resonating group method(RGM) in a chiral quark model, we find that the d* state has a mass of about 2.38–2.42 Ge V, a root-mean-square radius(RMS) of0.76–0.88 fm, and a CC fraction of 66%–68%. The last may cause a rather narrow width for the d* which, together with the quantum numbers and our calculated mass, is consistent with the newly observed resonance-like structure(M ≈2380 Me V, Γ≈70 Me V) in double-pionic fusion reactions reported by the WASA-at-COSY Collaboration.
A phenomenological Lagrangian approach is employed to study the electromagnetic properties of deuteron.The deuteron is regarded as a loosely bound state of a proton and a neutron. The deuteron electromagnetic form factors are expressed in light-front representation in the transverse plane. The transverse charge density of the deuteron is discussed.
The phenomenon of the near ppˉ-threshold enhancement observed in the J/ψ→γ pp decay is studied by using the enhancement factor method with a simpler one-pion-exchange potential between p and p. The Jost function caused by the mentioned potential is perturbatively calculated in the zero-th order approximation, and the corresponding enhancement factor is obtained. It is found that such a final state interaction offers an important contribution to the decay width near the ppˉ-threshold, although it is not large enough. To explain the decay data, a phenomenological factor G(p) with the form of 285500/(m 2 π + p 2 ) should be introduced. A further calculation including the p-dependent bare T -matrix, a more realistic N ˉ N potential and the contribution from the higher-order wave functions would provide a better understanding of the decay data and even the existence of the baryonium ppˉ. The near ppˉ-threshold behavior of the decay width in the J/ψ→π 0 pp process is also discussed.
