Measurement of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>e</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mo stretchy="false">→</mml:mo><mml:msup><mml:mi>π</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msup><mml:mi>D</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>D</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math> cross sections at center-of-mass energies from 4.190 to 4.946 GeV
M. Ablikim, М. Н. Ачасов, P. Adlarson, M. Albrecht, R. Aliberti, A. Amoroso, M. R. An, Q. An, X. H. Bai, Y. Bai, O. Bakina, R. Baldini Ferroli, I. Balossino, Y. Ban, V. Batozskaya, D. Becker, K. Begzsuren, N. Berger, M. Bertani, D. Bettoni, F. Bianchi, J. Bloms, A. Bortone, I. Boyko, R. A. Briere, A. Brueggemann, H. Cai, X. Z. Cai, A. Calcaterra, G. F. Cao, N. Cao, S. A. Çetin, J. F. Chang, W. L. Chang, G. Chelkov, C. Chen, Chao Chen, G. Chen, H. S. Chen, Mingliang Chen, S. J. Chen, S. M. Chen, T. Chen, X. R. Chen, X. T. Chen, Y. B. Chen, Z. J. Chen, W. S. Cheng, S. K. Choi, X. Chu, G. Cibinetto, F. Cossio, J. J. Cui, H. L. Dai, J. P. Dai, A. Dbeyssi, R. E. de Boer, D. Dedovich, Z. Y. Deng, A. Denig, I. Denysenko, M. Destefanis, F. De Mori, Y. Ding, J. Dong, L. Y. Dong, M. Y. Dong, X. Dong, S. X. Du, P. Egorov, Y. L. Fan, J. Fang, S. S. Fang, Wenxing Fang, Y. Fang, R. Farinelli, L. Fava, F. Feldbauer, G. Felici, C. Q. Feng, J. H. Feng, K. Fischer, M. Fritsch, C. Fritzsch, C. D. Fu, He Gao, Yang Gao, Yang Gao, S. Garbolino, I. Garzia, P. T. Ge, Z. W. Ge, C. Geng, E. Gersabeck, A. Gilman, L. Gong, W. X. Gong, W. Gradl, M. Greco, L. M. Gu
Abstract
Using data samples collected with the BESIII detector operating at the BEPCII storage ring, we measure the cross sections of the ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{D}^{+}{D}^{\ensuremath{-}}$ process at center-of-mass energies from 4.190 to 4.946 GeV with a partial reconstruction method. Resonance structures are seen and the cross section line shape can be described by the coherent sum of either two Breit-Wigner functions or a Breit-Wigner function and a phase space term. The mass and width of the resonance at about 4.4 GeV are determined to be $(4371.6\ifmmode\pm\else\textpm\fi{}2.5\ifmmode\pm\else\textpm\fi{}9.2)\text{ }\mathrm{MeV}/{c}^{2}$ and $(167\ifmmode\pm\else\textpm\fi{}4\ifmmode\pm\else\textpm\fi{}29)\text{ }\mathrm{MeV}$, respectively, which are in agreement with those of the $\ensuremath{\psi}(4360)$ or $Y(4390)$ state. The spin-$3D$-wave charmonium state $X(3842)$ is searched for through the ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}X(3842)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{D}^{+}{D}^{\ensuremath{-}}$ process, and evidence with a significance of $4.2\ensuremath{\sigma}$ is found in the data samples with center-of-mass energies from 4.6 to 4.7 GeV.