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arXiv · 2508.17819

Search for CP violation in $e^{+}e^{-} \to \psi(3770) \to D^{0}\bar{D}^{0}$ via $D -> K^{0}_{S} \pi^{0}$

BESIII Collaboration·M. Ablikim·M. N. Achasov·P. Adlarson·X. C. Ai·R. Aliberti·A. Amoroso·Q. An·Y. Bai·O. Bakina·Y. Ban·H. -R. Bao·V. Batozskaya·K. Begzsuren·N. Berger·M. Berlowski·M. B. Bertani·D. Bettoni·F. Bianchi·E. Bianco·A. Bortone·I. Boyko·R. A. Briere·A. Brueggemann·H. Cai·M. H. Cai·X. Cai·A. Calcaterra·G. F. Cao·N. Cao·S. A. Cetin·X. Y. Chai·J. F. Chang·T. T. Chang·G. R. Che·Y. Z. Che·C. H. Chen·Chao Chen·G. Chen·H. S. Chen·H. Y. Chen·M. L. Chen·S. J. Chen·S. L. Chen·S. M. Chen·T. Chen·X. R. Chen·X. T. Chen·X. Y. Chen·Y. B. Chen·Y. Q. Chen·Z. Chen·Z. K. Chen·J. Cheng·L. N. Cheng·S. K. Choi·X. Chu·G. Cibinetto·F. Cossio·J. Cottee-Meldrum·H. L. Dai·J. P. Dai·A. Dbeyssi·R. E. de Boer·D. Dedovich·C. Q. Deng·Z. Y. Deng·A. Denig·I. Denisenko·M. Destefanis·F. De Mori·B. Ding·X. X. Ding·Y. Ding·Y. X. Ding·J. Dong·L. Y. Dong·M. Y. Dong·X. Dong·M. C. Du·S. X. Du·X. L. Du·Y. Y. Duan·Z. H. Duan·P. Egorov·G. F. Fan·J. J. Fan·Y. H. Fan·J. Fang·S. S. Fang·W. X. Fang·Y. Q. Fang·R. Farinelli·L. Fava·F. Feldbauer·G. Felici·C. Q. Feng·J. H. Feng·L. Feng·Q. X. Feng
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Abstract

Utilizing data sample of electron-positron collisions recorded with the BESIII detector at the center of mass energy of 3.773 GeV, corresponding to an integrated luminosity of 20.28 fb$^{-1}$, we report the first search for the CP forbidden process $e^+e^- \to \psi(3773) \to D^0\bar{D}^0 \to (K^0_S\pi^0)(K^0_S\pi^0)$. No significant signal is observed. We set the upper limit on the observed cross section to be 7.37 fb, and the upper limit on the joint branching fraction of the C-odd correlated neutral $D$ pair $\mathcal{B}[(D^{0} \bar{D}^{0})_{\text{C-odd}} \to (K^{0}_{S} \pi^{0})(K^{0}_{S} \pi^{0})] < 2.04 \times 10^{-6}$ at the 90% confidence level.

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BESIII Collaboration, M. Ablikim, M. N. Achasov, P. Adlarson, X. C. Ai, R. Aliberti, A. Amoroso, Q. An, Y. Bai, O. Bakina, Y. Ban, H. -R. Bao, V. Batozskaya, K. Begzsuren, N. Berger, M. Berlowski, M. B. Bertani, D. Bettoni, F. Bianchi, E. Bianco, A. Bortone, I. Boyko, R. A. Briere, A. Brueggemann, H. Cai, M. H. Cai, X. Cai, A. Calcaterra, G. F. Cao, N. Cao, S. A. Cetin, X. Y. Chai, J. F. Chang, T. T. Chang, G. R. Che, Y. Z. Che, C. H. Chen, Chao Chen, G. Chen, H. S. Chen, H. Y. Chen, M. L. Chen, S. J. Chen, S. L. Chen, S. M. Chen, T. Chen, X. R. Chen, X. T. Chen, X. Y. Chen, Y. B. Chen, Y. Q. Chen, Z. Chen, Z. K. Chen, J. Cheng, L. N. Cheng, S. K. Choi, X. Chu, G. Cibinetto, F. Cossio, J. Cottee-Meldrum, H. L. Dai, J. P. Dai, A. Dbeyssi, R. E. de Boer, D. Dedovich, C. Q. Deng, Z. Y. Deng, A. Denig, I. Denisenko, M. Destefanis, F. De Mori, B. Ding, X. X. Ding, Y. Ding, Y. X. Ding, J. Dong, L. Y. Dong, M. Y. Dong, X. Dong, M. C. Du, S. X. Du, X. L. Du, Y. Y. Duan, Z. H. Duan, P. Egorov, G. F. Fan, J. J. Fan, Y. H. Fan, J. Fang, S. S. Fang, W. X. Fang, Y. Q. Fang, R. Farinelli, L. Fava, F. Feldbauer, G. Felici, C. Q. Feng, J. H. Feng, L. Feng, Q. X. Feng. 2025-08-25. Search for CP violation in $e^{+}e^{-} \to \psi(3770) \to D^{0}\bar{D}^{0}$ via $D -> K^{0}_{S} \pi^{0}$. https://doi.org/10.1103/dwlf-f4jn

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