Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userScalar hidden-charm tetraquark states with QCD sum rules
182
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
In this article, we study the masses and pole residues of the pseudoscalar-diquark-pseudoscalar-antidiquark type and vector-diquark-vector-antidiquark type scalar hidden-charm $cubar{c}bar{d}$ ($cubar{c}bar{s}$) tetraquark states with QCD sum rules by taking into account the contributions of the vacuum condensates up to dimension-10 in the operator product expansion. The predicted masses can be confronted with the experimental data in the future. Possible decays of those tetraquark states are also discussed.
rate research
Read More
In the present work, we take the scalar, pseudoscalar, axialvector, vector and tensor (anti)diquark operators as the elementary constituents to construct vector four-quark currents without introducing explicit P-waves, and explore the mass spectrum of the vector hidden-charm tetraquark states via the QCD sum rules comprehensively, and revisit the assignments of the $Y$ states in the scenario of tetraquark states. The predicted vector hidden-charm tetraquark states can be confronted to the experimental data in the future.
Very recently, the LHCb Collaboration observed distinct structures with the $ccbar{c}bar{c}$ in the $J/Psi$-pair mass spectrum. In this work, we construct four scalar ($J^{PC} = 0^{++}$) $[8_c]_{Qbar{Q^prime}}otimes [8_c]_{Q^prime bar{Q}}$ type currents to investigate the fully-heavy tetraquark state $Q Q^prime bar{Q} bar{Q^prime}$ in the framework of QCD sum rules, where $Q=c, b$ and $Q^prime = c, b$. Our results suggest that the broad structure around 6.2-6.8 GeV can be interpreted as the $0^{++}$ octet-octet tetraquark states with masses $6.44pm 0.11$ GeV and $6.52pm 0.10$ GeV, and the narrow structure around $6.9$ GeV can be interpreted as the $0^{++}$ octet-octet tetraquark states with masses $6.87pm 0.11$ GeV and $6.96pm 0.11$ GeV, respectivley. Extending to the b-quark sector,the masses of their fully-bottom partners are found to be around 18.38-18.59 GeV. Additionally, we also analyze the spectra of the $[cbar{c}][bbar{b}]$ and $[cbar{b}] [b bar{c}]$ tetraquark states, which lie in the range of 12.51-12.74 GeV and 12.49-12.81 GeV, respectively.
In the present work, we investigate the axialvector doubly-charmed tetraquark molecular states without strange, with strange and with doubly-strange via the QCD sum rules, and try to make assignment of the $T^+_{cc}$ from the LHCb collaboration in the scenario of molecular states. The predictions favor assigning the $T^+_{cc}$ to be the heavier $DD^{*}$ molecular state with the spin-parity $J^P=1^+$, while the lighter $DD^{*}$ molecular state with the spin-parity $J^P=1^+$ still escapes experimental detections. All the predicted doubly-charmed tetraquark molecular states can be confronted to the experimental data in the future.
Using the QCD sum rule approach we investigate the possible four-quark structure of the recently observed charmed scalar mesons $D_0^{0}(2308)$ (BELLE) and $D_0^{0,+}(2405)$ (FOCUS) and also of the very narrow $D_{sJ}^{+}(2317)$, firstly observed by BABAR. We use diquak-antidiquark currents and work to the order of $m_s$ in full QCD, without relying on $1/m_c$ expansion. Our results indicate that a four-quark structure is acceptable for the resonances observed by BELLE and BABAR: $D_0^{0}(2308)$ and $D_{sJ}^{+}(2317)$ respectively, but not for the resonances observed by FOCUS: $D_0^{0,+}(2405)$.
The purpose of the present study is to explore the mass spectrum of the hidden charm tetraquark states within a diquark model. Proposing that a tetraquark state is composed of a diquark and an antidiquark, the masses of all possible $[qc][bar{q}bar{c}]$, $[sc][bar{s}bar{c}]$, and $[qc][bar{s}bar{c}]$ $left([sc][bar{q}bar{c}]right)$ hidden charm tetraquark states are systematically calculated by use of an effective Hamiltonian, which contains color, spin, and flavor dependent interactions. Apart from the $X(3872)$, $Z(3900)$, $chi_{c2}(3930)$, and $X(4350)$ which are taken as input to fix the model parameters, the calculated results support that the $chi_{c0}(3860)$, $X(4020)$, $X(4050)$ are $[qc][bar{q}bar{c}]$ states with $I^GJ^{PC}=0^+0^{++}$, $1^+1^{+-}$, and $1^-2^{++}$, respectively, the $chi_{c1}(4274)$ is an $[sc][bar{s}bar{c}]$ state with $I^GJ^{PC}=0^+1^{++}$, the $X(3940)$ is a $[qc][bar{q}bar{c}]$ state with $I^GJ^{PC}=1^-0^{++}$ or $1^-1^{++}$, the $Z_{cs}(3985)^-$ is an $[sc][bar{q}bar{c}]$ state with $J^{P}=0^{+}$ or $1^+$, and the $Z_{cs}(4000)^+$ and $Z_{cs}(4220)^+$ are $[qc][bar{s}bar{c}]$ states with $J^{P}=1^{+}$. Predictions for other possible tetraquark states are also given.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
