Related papers: phi2/alpha
We present recent measurements of the unitarity triangle angle phi2(alpha) using B -> pi pi, B -> rho rho, and B -> rho pi decays. The measurements are based on data samples collected with the Belle and BaBar detectors at the KEKB and…
The Belle and BaBar experiments have measured branching fractions and CP asymmetries in the charmless decay modes B0->pi+pi-, B0->rho+pi-/rho-pi+, and B0->rho+rho-. From these measurements, constraints upon the CKM angle phi_2 can be…
We overview recent measurements in B -> rho rho decays which are based on data samples collected at the PEP-II and KEKB asymmetric-energy e+e- colliders with the BABAR and Belle detectors. Special emphasis is given to the determination of…
The Belle experiment has measured branching fractions and CP asymmetries for the charmless decays B0->pi+pi- and B0->rho+-pi-+. From these measurements, constraints upon the CKM angle phi_2 can be obtained. These constraints indicate that…
B meson decays involving b -> u transitions are sensitive to the unitarity triangle angle alpha (or phi2). The BaBar and Belle experiments have studied B-meson decays to pipi, rhopi and rhorho final states. It is possible to combine these…
We present a summary of the measurements of the CKM angle, alpha (phi2), performed by the BaBar and Belle experiments which collect BBbar pairs at the Y(4S) resonance produced in asymmetric e+ e- collisions. We discuss the measurements of…
We present a summary of measurements sensitive to the CKM angle \phi 2 (\alpha), performed by the BaBar and the Belle experiments which both collect B\bar{B} pairs produced at the \Upsilon(4S) resonance in asymmetric e+e- collisions. We…
We present measurements of time-dependent asymmetries in decays of neutral B mesons to the final states B0 -> rho+ pi-. Measurements are based on a 140 fb-1 data sample collected at the Upsilon(4S) resonance with the Belle detector at the…
The Belle experiment has used several methods to measure or constrain the angles phi_1, phi_2, and phi_3 (or beta, alpha, and gamma) of the CKM unitarity triangle. The results are sin(2phi_1) = 0.728 \pm 0.056 (stat) \pm 0.023 (syst) or…
In the neutral B meson system, it is possible to measure the CKM angle alpha using the decay mode b -> u ubar d in the presence of pollution from gluonic b -> d penguin decays. Here the recent status of the measurements of CP-violating…
We report recent measurements of the CKM angle alpha using data collected by the BABAR detector at the PEP-II asymmetric-energy e+e- collider at the SLAC National Accelerator Laboratory. In addition to improved constraints on alpha from the…
B-meson decays involving b->u transitions are sensitive to the Unitarity Triangle angle alpha (or phi_2). The B-factories at SLAC and KEK have made significant progress toward the measurement of alpha in recent years. This paper summarizes…
We have measured the branching fraction B, longitudinal polarization fraction f_L, and CP asymmetry coefficients A and S for B0->rho+rho- decays with the Belle detector at the KEKB e+e- collider using 253 fb-1 of data. We obtain B = [22.8…
We present recent measurements of the CKM angle alpha using data collected by the BABAR detector at the PEP-II asymmetric-energy e^+e^- collider at the SLAC National Accelerator Laboratory, operating at the Upsilon(4S) resonance. We present…
We present a summary of measurements sensitive to the CKM angle $\phi_2$, performed by the Belle experiment using the final data sample of $772 \times 10^{6}$ $B\bar{B}$ pairs produced at the $\Upsilon(4S)$ resonance at the KEK asymmetric…
The measurements of the angle alpha (phi2) of the unitarity triangle at the B factories are reviewed. The value of alpha determined by combining the results obtained in the B to pi pi, B to rho pi, and B to rho rho modes by both the BABAR…
Defining a most economical parametrization of time-dependent B-> rho^\pm pi^\mp decays, including a measurable phase alpha_{eff} which equals the weak phase alpha in the limit of vanishing penguin amplitudes, we propose two ways for…
We present improved measurements of the branching fractions and CP-asymmetries in the B0 --> pi+ pi-, B0 --> pi0 pi0, and B+ --> rho+ rho0 decays, which impact the determination of alpha. We find S(pi+ pi-) = -0.68 +/- 0.10 +/- 0.03 C(pi+…
The CKM angle $ \phi_{3} $ is the only angle of the unitarity triangle that is accessible with tree-level decays in a theoretically clean way. The Belle II experiment is a substantial upgrade of the Belle detector and will operate at the…
The current results on B to pipi decays and SU2 constraints on the Unitarity Triangle angle alpha or phi_2 from the B-factories are summarised. Based on these measurements, predictions of the isospin analysis constraints at the end of the…