The main characteristics of coherent bremsstrahlung (CBS) for the Beijing Electron-Positron Collider are calculated. At this collider dNγ~3 x 10^(8) dE_(γ)/E_(γ) photons of CBS will be emitted for a single collisio...The main characteristics of coherent bremsstrahlung (CBS) for the Beijing Electron-Positron Collider are calculated. At this collider dNγ~3 x 10^(8) dE_(γ)/E_(γ) photons of CBS will be emitted for a single collision of the beams in the energy range E_(γ)< 240 eV. It seems that CBS can be a potential tool for optimizing collisions and measuring beam parameters. Indeed, the bunch length σz can be found from the CBS spectrum because critical energy Ec ∝ 1/σz;the horizontal transverse bunch size σx is related to dNγ∝1/σ^(2)_(x). In addition, CBS may be very useful for a fast control over an impact parameter R between the colliding bunch axes.展开更多
For a possible fourth generation down quark of mass 23GeV we discuss the problems on the energy gap between hidden and open channels for the new flavor and on peculiar fermion mass relations in view of the grand unifi...For a possible fourth generation down quark of mass 23GeV we discuss the problems on the energy gap between hidden and open channels for the new flavor and on peculiar fermion mass relations in view of the grand unification.It is unlikely to be the conventionally expected fourth generation down quark.展开更多
It is assumed in this paper that the interquark(or gluon)forces are dominated by color octet exchange,which leads to the attractive forces to form colored bound states.The mass spectrum of colored states is discussed ...It is assumed in this paper that the interquark(or gluon)forces are dominated by color octet exchange,which leads to the attractive forces to form colored bound states.The mass spectrum of colored states is discussed in two quasi-confinement models.A qualitative prediction of the experimental signature on the colored bound states is included.展开更多
基金the National Natural Science Foundation of China and the Russian Foundation for Basic Research(code 96-02-19114).
文摘The main characteristics of coherent bremsstrahlung (CBS) for the Beijing Electron-Positron Collider are calculated. At this collider dNγ~3 x 10^(8) dE_(γ)/E_(γ) photons of CBS will be emitted for a single collision of the beams in the energy range E_(γ)< 240 eV. It seems that CBS can be a potential tool for optimizing collisions and measuring beam parameters. Indeed, the bunch length σz can be found from the CBS spectrum because critical energy Ec ∝ 1/σz;the horizontal transverse bunch size σx is related to dNγ∝1/σ^(2)_(x). In addition, CBS may be very useful for a fast control over an impact parameter R between the colliding bunch axes.
文摘For a possible fourth generation down quark of mass 23GeV we discuss the problems on the energy gap between hidden and open channels for the new flavor and on peculiar fermion mass relations in view of the grand unification.It is unlikely to be the conventionally expected fourth generation down quark.
文摘It is assumed in this paper that the interquark(or gluon)forces are dominated by color octet exchange,which leads to the attractive forces to form colored bound states.The mass spectrum of colored states is discussed in two quasi-confinement models.A qualitative prediction of the experimental signature on the colored bound states is included.
