  We study the influence of the in-medium mass difference between boson and
antiboson on their spectra. The in-medium mass difference may lead to a
difference between the transverse momentum spectra of boson and antiboson. This
effect increases with the increasing in-medium mass difference between boson
and antiboson. The difference between the transverse momentum spectra of boson
and antiboson increases with the increasing expanding velocity of the source
and decreases with the increasing transverse momentum in large transverse mass
region (mT > 1:6 GeV). The interactions between the hadron and the medium may
increase with the increasing temperature of the medium and the higher
freeze-out temperature may lead to a larger mass difference between boson and
antiboson, and may give rise to a larger difference between the transverse
momentum spectra of boson and antiboson for higher freeze-out temperature.
