Open-charm tetraquark $$X_c$$ X c and open-bottom tetraquark $$X_b$$ X b

Abstract

Abstract Motivated by the LHCb observation of exotic states $$X_{0,1}(2900)$$ X 0 , 1 ( 2900 ) with four open quark flavors in the $$D^- K^+$$ D - K + invariant mass distribution in the decay channel $$B^\pm \rightarrow D^+ D^- K^\pm $$ B ± → D + D - K ± , we study the spectrum and decay properties of the open charm tetraquarks. Using the two-body chromomagnetic interactions, we find that the two newly observed states can be interpreted as a radial excited tetraquark with $$J^P=0^+$$ J P = 0 + and an orbitally excited tetraquark with $$J^P=1^-$$ J P = 1 - , respectively. We then explore the mass and decays of the other flavor-open tetraquarks made of $$su {\bar{d}} {\bar{c}}$$ s u d ¯ c ¯ and $$ d s {\bar{u}} {\bar{c}}$$ d s u ¯ c ¯ , which are in the $${\bar{6}}$$ 6 ¯ or 15 representation of the flavor SU(3) group. We point that these two states can be found through the decays: $$X^{(\prime )}_{d s \bar{u}\bar{c}}\rightarrow (D^- K^-, D_s^- \pi ^-) $$ X d s u ¯ c ¯ ( ′ ) → ( D - K - , D s - π - ) , and $$X^{(\prime )}_{s u \bar{d}\bar{c}}\rightarrow D_s^-\pi ^+ $$ X s u d ¯ c ¯ ( ′ ) → D s - π + . We also apply our analysis to open bottom tetraquark $$X_b$$ X b and predict their masses. The open-flavored $$X_b$$ X b can be discovered through the following decays: $$X_{ud{\bar{s}}\bar{b}}\rightarrow B^0K^+$$ X u d s ¯ b ¯ → B 0 K + , $$X^{(\prime )}_{d s \bar{u}\bar{b}}\rightarrow (B^0 K^-, B_s^0 \pi ^-) $$ X d s u ¯ b ¯ ( ′ ) → ( B 0 K - , B s 0 π - ) , and $$X^{(\prime )}_{s u \bar{d}\bar{b}}\rightarrow B_s^0\pi ^+ $$ X s u d ¯ b ¯ ( ′ ) → B s 0 π + .