Measurement of the singly Cabibbo-suppressed decay $ {\Lambda}_c^{+}\to p{\eta}^{\prime } $ with deep learning

Using 4 . 5 fb − 1 of e + e − collision data collected with the BESIII detector at center-of-mass energies from 4.600 to 4.699 GeV, we report a measurement of the singly Cabibbo-suppressed decay ${\Lambda}_c^{+}\to p{\eta}^{\prime }$ with the single-tag method. To effectively distinguish the signal from the large backgrounds, we exploit a deep-learning classifier built on a Transformer-based neural network. Extensive validation and uncertainty quantification are carried out. The ${\Lambda}_c^{+}\to p{\eta}^{\prime }$ signal is observed with a statistical significance of 3 . 1 σ . The ratio of branching fractions of $\mathcal{B}\left({\Lambda}_c^{+}\to p{\eta}^{\prime}\right)/\mathcal{B}\left({\Lambda}_c^{+}\to p\omega \right)=0.55\pm 0.22\pm 0.05$ is obtained, where the first uncertainty is statistical and the second systematic.