Phys.Rev.Lett.99:211601,2007 We report the first search for CP violating decays of the $\Upsilon(4S)$
using a data sample that contains 535 million $\Upsilon(4S)$ mesons with the
Belle detector at ...the KEKB asymmetric-energy e^+ e^- collider. A partial
reconstruction technique is employed to enhance the signal sensitivity. No
significant signals were observed. We obtain an upper limit of $4 \times
10^{-7}$ at the 90 % confidence level for the branching fractions of the $CP$
violating modes, $\Upsilon(4S) \to B^0\bar{B}^0 \to J/\psi K^0_S +
J/\psi(\eta_c) K^0_S$. Extrapolating the result, we find that an observation
with 5$\sigma$ significance is expected with a 30 ab^{-1} data sample, which is
within the reach of a future super B factory.
Using only cosmic microwave background polarization data from the POLARBEAR experiment, we measure \(B\)-mode polarization delensing on subdegree scales at more than \(5\sigma\) significance. We ...achieve a 14% \(B\)-mode power variance reduction, the highest to date for internal delensing, and improve this result to 2% by applying for the first time an iterative maximum a posteriori delensing method. Our analysis demonstrates the capability of internal delensing as a means of improving constraints on inflationary models, paving the way for the optimal analysis of next-generation primordial \(B\)-mode experiments.