Measurement of $B^0\to {\pi }^{+}{\pi }^{-}{\pi }^{+}{\pi }^{-}$ Decays and Search for $B^0\to {\rho }^0{\rho }^0$

Abstract

We report on a search for the decay $B^0\to {\rho }^0{\rho }^0$ and other charmless modes with a ${\pi }^{+}{\pi }^{-}{\pi }^{+}{\pi }^{-}$ final state, including $B^0\to {\rho }^0{\pi }^{+}{\pi }^{-}$, non-resonant $B^0\to 4{\pi }^{\pm }$, $B^0\to {\rho }^0{f}_0(980)$, $B^0\to f_0(980)f_0(980)$ and $B^0\to f_0(980){\pi }^{+}{\pi }^{-}$. These results are obtained from a data sample containing 657 million $B\overline{B}$ pairs collected with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. We set an upper limit on $\mathcal{B}(B^0\to {\rho }^0{\rho }^0)$ of $1.0\times 10^{-6}$ at the 90% confidence level (C.L.). From our $B^0\to {\rho }^0{\rho }^0$ measurement and an isospin analysis, we determine the Cabibbo-Kobayashi-Maskawa phase ${\varphi }_2$ to be $91.7\pm 14.9$ degrees. We find excesses in $B^0\to {\rho }^0{\pi }^{+}{\pi }^{-}$ and non-resonant $B^0\to 4{\pi }^{\pm }$ with 1.3$\sigma$ and 2.5$\sigma$ significance, respectively. The corresponding branching fractions are less than $12.0\times 10^{-6}$ and $19.3\times 10^{-6}$ at the 90% C.L. In addition, we set 90% C.L. upper limits as follows: $\mathcal{B}(B^0\to {\rho }^0{f}_0(980))<0.3\times 10^{-6}$, $\mathcal{B}(B^0\to f_0(980)f_0(980))<0.1\times 10^{-6}$, and $\mathcal{B}(B^0\to f_0(980){\pi }^{+}{\pi }^{-})<3.8\times 10^{-6}$.

6 pages, 2 figures. Submitted to PRD(RC)

References in corpus (3)

• Branching fractions, polarisation and asymmetries of B -> VV decays
• Observation of Direct CP-Violation in B0 --> pi+pi- Decays and Model-Independent Constraints on phi2
• Measurement of CP Asymmetry in a Time-Dependent Dalitz Analysis of B^0 \to (ρπ)^0 and a Constraint on the Quark Mixing Matrix Angle ϕ_2

Cited by in corpus (1)

• Measurements of Charmless Hadronic b->s Penguin Decays in the pi+pi-K+pi- Final State and First Observation of B0 -> rho0K+pi-