91色情片

After a major overhaul, the world鈥檚 only electron-proton collider got back to
work this week. The revamped HERA particle accelerator at the DESY research
centre in Hamburg will quadruple its 鈥渉it rate鈥�, the rate at which particles
smash into each other. Experiments at the accelerator reveal quarks and gluons
milling around inside the proton and could soon shed light on whether quarks
really are elementary particles, as we believe today. 鈥淲e are heading into
unexplored territory,鈥� says Albrecht Wagner, DESY鈥檚 director.