Abstract
We use the Laplace/Borel sum rules (LSR) and the finite energy/local duality sum rules (FESR) to investigate the non-strange $ud\bar u\bar d$ and hidden-strange $us\bar u\bar s$ tetraquark states with exotic quantum numbers $J^{PC}=0^{+-}$ . We systematically construct all eight possible tetraquark currents in this channel without covariant derivative operator. Our analyses show that the $ud\bar u\bar d$ systems have good behaviour of sum rule stability and expansion series convergence in both the LSR and FESR analyses, while the LSR for the $us\bar u\bar s$ states do not associate with convergent OPE series in the stability regions and only the FESR can provide valid results. We give the mass predictions $1.43\pm0.09$ GeV and $1.54\pm0.12$ GeV for the $ud\bar u\bar d$ and $us\bar u\bar s$ tetraquark states, respectively. Our results indicate that the $0^{+-}$ isovector $us\bar u\bar s$ tetraquark may only decay via weak interaction mechanism, e.g. $X_{us\bar{u}\bar{s}}\to K\pi\pi$, since its strong decays are forbidden by kinematics and the symmetry constraints on the exotic quantum numbers. It is predicted to be very narrow, if it does exist. The $0^{+-}$ isoscalar $us\bar u\bar s$ tetraquark is also predicted to be not very wide because its dominate decay mode $X_{us\bar{u}\bar{s}}\to\phi\pi\pi$ is in $P$-wave.
Highlights
In the constituent quark model, mesons consist of a pair of quark and antiquark [1,2]. They can be characterized by the isospin I, the total angular momentum J, the parity P, and the charge-conjugation parity C
The combinations JPC 1⁄4 0−−; 0þ−; 1−þ; 2þ− are not allowed for the conventional qqsystems
Have a lower dimension than those in Ref. [23], which will result in better operator product expansion (OPE) behaviors and mass predictions
Summary
In the constituent quark model, mesons consist of a pair of quark and antiquark (qq ) [1,2] They can be characterized by the isospin I, the total angular momentum J, the parity P, and the charge-conjugation parity C (for charge neutral states). It is useful to define the G parity instead of C parity For such meson states, the allowed J ≤ 2 quantum numbers are JPC 1⁄4 0−þ; 0þþ; 1−−; 1þ−; 1þþ; 2−−; 2−þ; 2þþ. The combinations JPC 1⁄4 0−−; 0þ−; 1−þ; 2þ− are not allowed for the conventional qqsystems In other words, they are exotic quantum numbers in the quark model. For hadrons with exotic quantum numbers, the 1−þ hybrid meson has been extensively studied since it was predicted to be the lightest hybrid state [15]. The possible decay patterns of the 0þ− tetraquark states will be discussed last
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
