Probing the photon polarization in B -> K*gamma with conversion

作者：Bishara Fady^*; Robinson Dean J

来源：The Journal of High Energy Physics, 2015, 2015(9): 013.

DOI：10.1007/JHEP09(2015)013

• Rare Decays
• B-Physics

We re-examine the possibility to measure the photon polarization in B -> K*gamma decays, via decays in which the photon subsequently undergoes nuclear conversion to a lepton pair. We obtain compact expressions for the full decay-plus-conversion amplitude. With these results we show that interference between the B -> (K* -> K pi)gamma decay and the gamma N -> l(+)l(-) N conversion permits both the ratio and relative weak phase between the left- and right-handed photon amplitudes to be probed by an angular observable, constructed from the final state dilepton, kaon and pion kinematic configuration. Exploiting this technique will be experimentally challenging. However, we present special kinematic cuts that enhance the statistical power of this technique by an O(1) factor. We verify this effect and extract pertinent angular kinematic distributions with dedicated numerical simulations.

• 出版日期2015-9-2