Speaker
Description
Measurements of the transverse polarization of lambda hyperons with
respect to their production plane are sensitive to the polarizing
fragmentation function $D_{1T}^{\perp \Lambda/q}$. This fragmentation
function might be part of the explanation of the significant
transverse polarization of Lambda in p+p scattering. It can also be seen
as the hadronization analogue to the Sivers function, since it
describes the transverse momentum dependent transverse polarization of
the hyperon. As a chiral-even, naive time-reversal-odd function it
also allows to test universality, in particular the sign, of these
functions between different processes.
We present the first observation of the transverse polarization of
Lambda hyperons in e+e- annihilation at or near $\sqrt{s}=10.58$ GeV using a dataset of about 800fb$^-1$ integrated luminosity collected by the Belle detector.
