Study of the Exclusive Initial-State-Radiation Production of the DDbar System

TL;DR

This study investigates the production of D Dbar pairs via initial-state radiation in electron-positron collisions, revealing known charmonium states and setting limits on the Y(4260) decay into D Dbar.

Contribution

It provides new measurements of D Dbar production spectra and sets upper limits on Y(4260) decays, enhancing understanding of charmonium states and exotic resonances.

Findings

Clear evidence of psi(3770) and structures near 3.9, 4.1, 4.4 GeV/c^2

No evidence for Y(4260) -> D Dbar, upper limit set

Data sample of 384 fb-1 from BABAR experiment

Abstract

A search for charmonium and other new states is performed in a study of exclusive initial-state-radiation production of D Dbar events from electron-positron annihilations at a center-of-mass energy of 10.58 GeV. The data sample corresponds to an integrated luminosity of 384 fb-1 and was recorded by the BABAR experiment at the PEP-II storage ring. The D Dbar mass spectrum shows clear evidence of the psi(3770) plus other structures near 3.9, 4.1, and 4.4 GeV/c^2. No evidence for Y(4260) -> D Dbar is observed, leading to an upper limit of B(Y(4260) -> D Dbar)/B(Y(4260) -> J/psi pi+ pi-) < 1.0 at 90 % confidence level.