A STRANGE state of matter that dominated the early universe could be used to create ultra-fast flashes of radiation, brief enough to capture what’s going on inside atomic nuclei.
To take snapshots of rapid processes you need brief flashes of light. Until now, the shortest pulses have been created by lasers – a quick blast can prompt atoms to release a burst of X-rays lasting only attosecondsMovie Camera (10-18 seconds, or a billionth of a billionth of a second). That is quick enough to capture the vibration of individual molecules, but far too slow for nuclear processes.
Now it may be possible to create pulses of radiation that last for only one millionth of an attosecond, say Andreas Ipp, now at the Vienna University of Technology, Austria, and his colleagues at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany.
Instead of lasers, the light would be emitted by an exotic, dense state of matter called a quark-gluon plasma – the same stuff the universe contained for a fraction of a second after the big bang. This soup of ultra-hot, subatomic building blocks of protons and neutrons may still be hiding inside neutron stars. On Earth, a quark-gluon plasma could be created in the lab by smashing heavy nuclei such as gold together at high speeds.
This short-lived plasma would emit bursts of gamma rays lasting for just a few yoctoseconds (10-24 seconds), the smallest unit of time that has its own prefix. When Ipp and colleagues modelled the plasma, they discovered that the gamma rays can sometimes be emitted in two closely spaced yoctosecond pulses (Physical Review Letters, DOI: 10.1103/PhysRevLett.103.152301, arXiv version).
Two flashes would enable the measurement of very rapid changes. “You could use it to make movies of really fast processes,” says Michael Strickland of Gettysburg College in Pennsylvania. Aimed at a target of ordinary matter, the gamma-ray pulses could reveal more about the vibrations and energies inside nuclei, which govern phenomena like radioactivity. …