We perform the first search for CP violation in Ds+→KS0K−π+π+ decays. We use a combined data set from the Belle and Belle II experiments, which study e+e− collisions at center-of-mass energies at or near the Υ(4S) resonance. We use 980 fb−1 of data from Belle and 428 fb−1 of data from Belle II. We measure six CP-violating asymmetries that are based on triple products and quadruple products of the momenta of final-state particles, and also the particles’ helicity angles. We obtain a precision at the level of 0.5% for D+→KS0K−π+π+ decays, and better than 0.3% for Ds+→KS0K−π+π+ decays. No evidence of CP violation is found. Our results for the triple-product asymmetries are the most precise to date for singly-Cabibbo-suppressed D+ decays. Our results for the other asymmetries are the first such measurements performed for charm decays.
Search for CP violation in $$ {D}_{(s)}^{+}\to {K}_S^0{K}^{-}{\pi}^{+}{\pi}^{+} $$ decays using triple and quadruple products
Bertacchi, V.;Bettarini, S.;Bussino, S.;Casarosa, G.;Corona, L.;Forti, F.;Massaccesi, L.;Mondal, S.;Paoloni, E.;Rizzo, G.;Tenchini, F.;Zani, L.;
2025-01-01
Abstract
We perform the first search for CP violation in Ds+→KS0K−π+π+ decays. We use a combined data set from the Belle and Belle II experiments, which study e+e− collisions at center-of-mass energies at or near the Υ(4S) resonance. We use 980 fb−1 of data from Belle and 428 fb−1 of data from Belle II. We measure six CP-violating asymmetries that are based on triple products and quadruple products of the momenta of final-state particles, and also the particles’ helicity angles. We obtain a precision at the level of 0.5% for D+→KS0K−π+π+ decays, and better than 0.3% for Ds+→KS0K−π+π+ decays. No evidence of CP violation is found. Our results for the triple-product asymmetries are the most precise to date for singly-Cabibbo-suppressed D+ decays. Our results for the other asymmetries are the first such measurements performed for charm decays.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.


