Analysis of the $$Z_c(4020)$$ Z c ( 4020 ) , $$Z_c(4025)$$ Z c ( 4025 ) , $$Y(4360)$$ Y ( 4360 ) , and $$Y(4660)$$ Y ( 4660 ) as vector tetraquark states with QCD sum rules

Abstract

In this article, we distinguish the charge conjugations of the interpolating currents, calculate the contributions of the vacuum condensates up to dimension-10 in the operator product expansion, and we study the masses and pole residues of the J PC = 1 −± hidden charmed tetraquark states with the QCD sum rules. We suggest a formulawith the effective mass M c = 1.8 GeV to estimate the energy scales of the QCD spectral densities of the hidden charmed tetraquark states, which works very well. The numerical results disfavor assigning the Z c (4020), Z c (4025), and Y (4360) as the diquark-antidiquark (with the Dirac-spinor structure C − Cγ μ ) type vector tetraquark states, and they favor assigning the Z c (4020), Z c (4025) as the diquark-antidiquark type 1 +− tetraquark states. While the masses of the tetraquark states with symbolic quark structures ccss and cc(uū + dd)/ √ 2 favor assigning the Y (4660) as the 1 −− diquark-antidiquark type tetraquark state, more experimental data are still needed to distinguish its quark constituents. There are no candidates for the positive charge conjugation vector tetraquark states; the predictions can be confronted with the experimental data in the future at the BESIII, LHCb and Belle-II.

Full‐Spectrum Solar‐Light‐Activated Photocatalysts for Light–Chemical Energy Conversion

“…Following this work, many studies have synthesized black TiO 2 through various methods. [60][61][62][63][64] However, some of the as-obtained black TiO 2 materials fail in visible light-driven photocatalysis, although the dramatic enhancement in light absorption is achieved. [61,64] We believe that the key factor is the balance between the light absorption enhanced by defects and the defect-induced carrier traps.…”

Surface oxygen-vacancy induced photocatalytic activity of La(OH)3 nanorods prepared by a fast and scalable method

“…[18][19][20] The light absorption range of semiconductor materials can be enhanced or expanded by introducing oxygen vacancies, which results in the extended light absorption spectra and band gap narrowing. 18,21 Recently, oxygen-vacancy associated properties have been widely surveyed in simple semiconductors, such as TiO 2 , [18][19][20]22 Fe 2 O 3 , 23 and ZnO. [24][25][26] However, to the best of our knowledge, the oxygen vacancies in La(OH) 3 and their influence on the band structure and photocatalytic activity have seldom been investigated.…”

Evidence for Octupole Correlations in Multiple Chiral Doublet Bands

“…Such chiral doublet bands were first observed in N ¼ 75 isotones [2]. So far, more than 30 experimental candidates have been reported in the A ∼ 80, 100, 130, and 190 mass regions [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20].Based on constrained triaxial covariant density functional theory (CDFT) calculations, it has been suggested that multiple chiral doublet (MχD) bands can exist in a single nucleus [21][22][23][24][25][26]. The theoretical prediction of MχD bands stimulated lots of experimental efforts [27][28][29][30][31].…”

“…Such chiral doublet bands were first observed in N ¼ 75 isotones [2]. So far, more than 30 experimental candidates have been reported in the A ∼ 80, 100, 130, and 190 mass regions [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20].…”