A new muon and K_Long detector based on scintillators will be used for the endcap and inner barrel regions in the Belle II experiment, currently under construction. The increased luminosity of the e+e- SuperKEKB collider entails challenging detector
requirements. We demonstrate that relatively inexpensive polystyrene scintillator stips with wave length shifting fibers ensure a sufficient light yield at the Silcon PhotoMultiplier (SiPM) photodetector, are robust and provide improved physics performance for the Belle II experiment compared to its predecessor, Belle.
We report a study of the decays B -> D_s1(2536)+ anti-D(*), where anti-D(*) is anti-D0, D- or D*-, using a sample of 657 x 10^6 B anti-B pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider.
The branching fractions of the decays B+ -> D_s1(2536)+ anti-D0, B0 -> D_s1(2536)+ D- and B0 -> D_s1(2536)+ D*- multiplied by that of D_s1(2536)+ -> (D*0K+ + D*+K0) are found to be (3.97+-0.85+-0.56) x 10^-4, (2.75+-0.62+-0.36) x 10^-4 and (5.01+-1.21+-0.70) x 10^-4, respectively.
In this report we summarize the most recent sin2phi_1 measurements in the b -> q anti-q s decays.
We report measurements of the branching fractions for the decays B->D_s1(2536)+ anti-D(*), where anti-D(*) is anti-D0, D- or D*-, and study of B->X(3872) K with X(3872) decaying to D*0 anti-D0 using a sample of 657 million B anti-B pairs recorded at
the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider.
We report recent measurements of the Unitarity triangle angles phi_1 and phi_2 using large data samples collected with Belle and BaBar detectors at e+e- asymmetric-energy colliders.
