BPeak and $\beta$ relaxation
$\beta$ relaxation is due to BPeak
thermally excited BPeak (liquid-like internal excitations) modes scatter/relax low-frequency phonons at 50K
but at higher temperatures equal-population of BPeak modes makes scattering very very weak - right?
real motions start close to the glass transition itself
2016 An Overview on Short and Long Time Relaxations in Glass-forming Supercooled Liquids
The short time relaxation is known as β-relaxation and the final long time relaxation is called α-relaxation
These results provide a clear connection between short-time dynamics and long-time structural relaxation in glass-forming liquids.