Probing new physics with the kaon decays K → ππ∋

The latest search for the rare kaon decay K+ ->pi+ nu(nu) over bar by the NA62 experiment has produced evidence for it with a branching fraction consistent with the prediction of the standard model. The new result implies that in this decay, with the nu(nu) over bar pair appearing as missing energy (is not an element of), the room for possible new physics is no longer sizable and that therefore its contributions to underlying four-particle s -> d is not an element of operators with parityeven ds quark bilinears have become significantly constrained. Nevertheless, we point out that appreciable manifestations from beyond the standard model induced by the corresponding operators with mainly parity-odd ds quark bilinears could still occur in K -> pi pi is not an element of modes, on which there are only minimal empirical details at present. We find in particular that new physics of this kind may enhance the branching fraction of K-L -> pi(0)pi(0) is not an element of to values reaching its current experimental upper limit and the branching fractions of K+ ->pi(+)pi(0)is not an element of and K-L ->pi(+)pi(-)is not an element of to the levels of 10(-7) and 10(-6) , respectively. Thus, quests for these decays in existing kaon facilities such as KOTO and NA62 or future ones could provide valuable information complementary to that gained from K ->pi is not an element of.