Recent results, status and prospects for the BESIII experiment

Isabella Garzia

doi:10.1088/1742-6596/631/1/012043

Abstract

We report the measurement of the asymmetry ACP of the branching fractions of D0 → K-π+ in the CP-odd and CP-even eigenstates using a data sample of 2.92 fb-1 collected with the BESIII detector at the center-of-mass energy √s = 3.773 GeV. With the measured ACP, the strong phase difference δKπ between the doubly Cabibbo-suppressed process D̄0 → K−π+ and the Cabibbo-favored process D0 → K−π+ is extracted. Using world- average values of external parameters, we obtain the most precise measurement of δKπ to date: cos δKπ = 1.02 ± 0.11 ± 0.06 ± 0.01. The first and second uncertainties are statistical and systematic, respectively, while the third arises from external input. Based on the same data sample a preliminary results of the parameter yCP in D0D̄0 oscillation is obtained. Finally, a summary of the recent results from charmonium spectroscopy is reported. The high statistics accumulated at the Y(4260) and Y(4360) energies help us to understand the nature and the proprieties of the XYZ states.

Highlights

Mixing between K0 and K0, B0 and B0, and Bs and Bs is well established, and is well described by the Standard Model (SM) box diagrams containing up-type (u, c, t) quarks
The first uncertainty is statistical, the second is systematic, and the third is due to the external input parameters
There is no significant evidence of the Zc(3900) structure in the Mhcπ± mass spectrum: adding the Zc(3900) mass and width fixed to the BESIII measurement [16], we find a significance of 2.1σ

Summary

Introduction

Mixing between K0 and K0, B0 and B0, and Bs and Bs is well established, and is well described by the Standard Model (SM) box diagrams containing up-type (u, c, t) quarks. In the first part of this report, we present the measurements of the strong phase δKπ and yCP obtained from center-of-mass a time-in√dependent energy s = 3.773 analysis. Final state, while nKπ,CP ± and Kπ,CP ± are the yields and detection efficiencies of double tag (DT) of the (CP ±, Kπ) final state, respectively In this analysis, we use 5 CP -even D0 decay modes (K+K−, π+π−, KS0 π0π0, π0π0, ρ0π0), and 3 CP -odd modes (KS0 π0, KS0 η, KS0 ω), with π0(η) → γγ, KS0 → π+π− and ω → π+π−π0. The first uncertainty is statistical, the second is systematic, and the third is due to the external input parameters This result is consistent with CLEO measurement[10] and provides the word best constrain on δKπ

Measurement of yCP

Findings

Conclusions