Search for lepton number violating decays of $$ {\textrm{D}}_{\textrm{s}}^{+} $$ → h−h0e+e

• Published in: The journal of high energy physics 2025-01, Vol.2025 (1), Article 109
• Main Authors: Ablikim, M., Achasov, M. N., Adlarson, P., Afedulidis, O., Ai, X. C., Aliberti, R., Amoroso, A., An, Q., Bai, Y., Bakina, O., Balossino, I., Ban, Y., Bao, H.-R., Batozskaya, V., Begzsuren, K., Berger, N., Berlowski, M., Bertani, M., Bettoni, D., Bianchi, F., Bianco, E., Bortone, A., Boyko, I., Briere, R. A., Brueggemann, A., Cai, H., Cai, X., Calcaterra, A., Cao, G. F., Cao, N., Cetin, S. A., Chai, X. Y., Chang, J. F., Che, G. R., Che, Y. Z., Chelkov, G., Chen, C., Chen, 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, Y. B., Chen, Y. Q., Chen, Z. J., Chen, Z. Y., Choi, S. K., Cibinetto, G., Cossio, F., Cui, J. J., Dai, H. L., Dai, J. P., Dbeyssi, A., de Boer, R. E., Dedovich, D., Deng, C. Q., Deng, Z. Y., Denig, A., Denysenko, I., Destefanis, M., De Mori, F., Ding, B., Ding, X. X., Ding, Y., Dong, J., Dong, L. Y., Dong, M. Y., Dong, X., Du, M. C., Du, S. X., Duan, Y. Y., Duan, Z. H., Egorov, P., Fan, Y. H., Fang, J., Fang, S. S., Fang, W. X., Fang, Y., Fang, Y. Q., Farinelli, R., Fava, L., Feldbauer, F., Felici, G., Feng, C. Q., Feng, J. H., Feng, Y. T., Fritsch, M., Fu, C. D., Fu, J. L., Fu, Y. W., Gao, H., Gao, X. B., Gao, Y. N.
• Format: Article
• Language: English
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP01(2025)109

Based on 7.33 fb − 1 of e + e − collision data collected by the BESIII detector operating at the BEPCII collider at center-of-mass energies from 4.128 to 4.226 GeV, a search for the Majorana neutrino ν m is conducted in the lepton-number-violating decays of $$ {D}_{\textrm{s}}^{+} $$ D s + → h − h 0 e + e + . Here, h − represents a K − or π − , and h 0 represents a π 0 , $$ {K}_S^0 $$ K S 0 or ϕ . No significant signal is observed, and the upper limits of their branching fractions at the 90% confidence level are determined to be $$ \mathcal{B} $$ B ( $$ {D}_{\textrm{s}}^{+} $$ D s + → ϕπ − e + e + ) < 6 . 9 × 10 − 5 , $$ \mathcal{B} $$ B ( $$ {D}_{\textrm{s}}^{+} $$ D s + → ϕK − e + e + ) < 9 . 9 × 10 − 5 , $$ \mathcal{B} $$ B ( $$ {D}_{\textrm{s}}^{+} $$ D s + → $$ {K}_S^0 $$ K S 0 π − e + e + ) < 1 . 3 × 10 − 5 , $$ \mathcal{B} $$ B ( $$ {D}_{\textrm{s}}^{+} $$ D s + → $$ {K}_S^0 $$ K S 0 K − e + e + ) < 2 . 9 × 10 − 5 , $$ \mathcal{B} $$ B ( $$ {D}_{\textrm{s}}^{+} $$ D s + → π − π 0 e + e + ) < 2 . 9 × 10 − 5 and $$ \mathcal{B} $$ B ( $$ {D}_{\textrm{s}}^{+} $$ D s + → K − π 0 e + e + ) < 3 . 4 × 10 − 5 . The Majorana neutrino is searched for with different mass assumptions within the range [0 . 20 , 0 . 80] GeV /c 2 in the decay of $$ {D}_{\textrm{s}}^{+} $$ D s + → ϕe + ν m with ν m → π − e + , and the upper limits of the branching fractions at the 90% confidence level are at the level of 10 − 5 –10 − 2 , depending on the mass of the Majorana neutrino.