829 research outputs found
Derivation of Covariant Dissipative Fluid Dynamics in the Renormalization-group Method
We derive generic relativistic hydrodynamical equations with dissipative
effects from the underlying Boltzmann equation in a mechanical and systematic
way on the basis of so called the renormalization-group (RG) method. A
macroscopic frame vector is introduced to specify the frame on which the
macroscopic dynamics is described. Our method is so mechanical with only few
ansatz that our method give a microscopic foundation of the available
hydrodynamical equations, and also can be applied to make a reduction of the
kinetic equations other than the simple Boltzmann equation.Comment: Serious typos and a minor one are corrected in p.6 and 7, and in p.1,
respectivel
Lepton Flavour Violation at an electron-photon collider
We study the LFV Higgs production processes e−γ → l�− ϕ (�l =
μ, τ ; ϕ = H,A) as a probe of Higgs-mediated LFV couplings at an electron-photon collider, where H and A are extra CP even and odd Higgs bosons, respectively, in the two Higgs doublet model. Under the constraints from the current data of muon and tau rare decay, the cross-section can be significantly large. It would improve the experimental upper bounds on the effective LFV coupling constants. In addition, the chirality nature of the LFV Higgs coupling constants can be measured by selecting electron beam polarizations
Higgs boson pair production in new physics models at hadron, lepton, and photon colliders
We discuss Higgs boson pair production processes at future hadron and lepton colliders including the photon collision option in several new physics models, i.e. the two-Higgs-doublet model, the scalar leptoquark model, the sequential
fourth-generation fermion model and the vectorlike quark model. Cross sections for these processes can differ significantly from the standard model predictions, due to the nondecoupling effect in the triple Higgs boson coupling constant. For the one-loop induced processes such as gg → hh and γγ → hh, new physics particles can mediate in a loop diagram, which can affect cross sections. Measurements of the Higgs boson pair production processes can be useful not only to test the standard model but also to explore new physics models
Lepton Flavour Violation at an electron-photon collider
We study the LFV Higgs production processes e−γ → l�− ϕ (�l =
μ, τ ; ϕ = H,A) as a probe of Higgs-mediated LFV couplings at an electron-photon collider, where H and A are extra CP even and odd Higgs bosons, respectively, in the two Higgs doublet model. Under the constraints from the current data of muon and tau rare decay, the cross-section can be significantly large. It would improve the experimental upper bounds on the effective LFV coupling constants. In addition, the chirality nature of the LFV Higgs coupling constants can be measured by selecting electron beam polarizations
Survival of charmonia above Tc in anisotropic lattice QCD
We find a strong evidence for the survival of and as
spatially-localized (quasi-)bound states above the QCD critical
temperature , by investigating the boundary-condition dependence of their
energies and spectral functions. In a finite-volume box, there arises a
boundary-condition dependence for spatially spread states, while no such
dependence appears for spatially compact states. In lattice QCD, we find almost
{\it no} spatial boundary-condition dependence for the energy of the
system in and channels for . We also
investigate the spectral function of charmonia above in lattice QCD using
the maximum entropy method (MEM) in terms of the boundary-condition dependence.
There is {\it no} spatial boundary-condition dependence for the low-lying peaks
corresponding to and around 3GeV at . These facts
indicate the survival of and as compact
(quasi-)bound states for .Comment: 4 pages, 1 figur
- …