Spectroscopy and decays of the fully-heavy tetraquarks Anwar, Muhammad Naeem; Ferretti, Jacopo; Guo, Feng-Kun ...
The European physical journal. C, Particles and fields,
08/2018, Letnik:
78, Številka:
8
Journal Article
Recenzirano
Odprti dostop
We discuss the possible existence of the fully-heavy tetraquarks. We calculate the ground-state energy of the
b
b
b
¯
b
¯
bound state, where
b
stands for the bottom quark, in a nonrelativistic ...effective field theory framework with one-gluon-exchange (OGE) color Coulomb interaction, and in a relativized diquark model characterized by OGE plus a confining potential. Our analysis advocates the existence of uni-flavor heavy four-quark bound states. The ground state
b
b
b
¯
b
¯
tetraquark mass is predicted to be
(
18.72
±
0.02
)
GeV. Mass inequality relations among the lowest
Q
Q
Q
¯
Q
¯
states, where
Q
∈
{
c
,
b
}
, and the corresponding heavy quarkonia are presented, which give the upper limit on the mass of ground state
Q
Q
Q
¯
Q
¯
. The possible decays of the lowest
b
b
b
¯
b
¯
are highlighted, which might provide useful references in the search for them in ongoing LHC experiments, and its width is estimated to be a few tens of MeV.
Advancing perovskite solar cell technologies toward their theoretical power conversion efficiency (PCE) requires delicate control over the carrier dynamics throughout the entire device. By ...controlling the formation of the perovskite layer and careful choices of other materials, we suppressed carrier recombination in the absorber, facilitated carrier injection into the carrier transport layers, and maintained good carrier extraction at the electrodes. When measured via reverse bias scan, cell PCE is typically boosted to 16.6% on average, with the highest efficiency of ∼19.3% in a planar geometry without antireflective coating. The fabrication of our perovskite solar cells was conducted in air and from solution at low temperatures, which should simplify manufacturing of large-area perovskite devices that are inexpensive and perform at high levels.
Aqueous zinc‐ion batteries (ZIBs) using the Zn metal anode have been considered as one of the next‐generation commercial batteries with high security, robust capacity, and low price. However, ...parasitic reactions, notorious dendrites and limited lifespan still hamper their practical applications. Herein, an eco‐friendly nitrogen‐doped and sulfonated carbon dots (NSCDs) is designed as a multifunctional additive for the cheap aqueous ZnSO4 electrolyte, which can overcome the above difficulties effectively. The abundant polar groups (‐COOH, ‐OH, ‐NH2, and ‐SO3H) on the CDs surfaces can regulate the solvation structure of Zn2+ through decreasing the coordinated active H2O molecules, and thus redistribute Zn2+ deposition to avoid side reactions. Some of the negatively charged NSCDs are adsorbed on Zn anode surface to isolate the H2O/SO42‐ corrosion through the electrostatic shielding effect. The synergistic effect of the doped nitrogen species and the surface sulfonic groups can induce a uniform electrolyte flux and a homogeneous Zn plating with a (002) texture. As a result, the excellent cycle life (4000 h) and Coulombic efficiency (99.5%) of the optimized ZIBs are realized in typical ZnSO4 electrolytes with only 0.1 mg mL‐1 of NSCDs additive.
Nitrogen‐doped and sulfonated carbon dots are designed as a multifunctional additive for the cheap aqueous ZnSO4 electrolyte, thus effectively regulating the solvation structure of Zn2+ to decrease the coordinated active water molecules and overcoming parasitic reactions, notorious dendrites and short lifespan, which finally improve electrochemical performance of aqueous zinc ion batteries.
We extend the chiral quark model for
u
,
d
,
c
and
b
quarks with vector mesons, which we proposed in the previous analysis, to a model with the
s
quark. We include the nonet pseudo-scalar and ...vector mesons together with the singlet scalar meson based on the SU(3)
L
×
SU(3)
R
chiral symmetry combined with the hidden local symmetry, which mediate force among
u
,
d
and
s
quarks. We fit the model parameters to the known ground state mesons and baryons. We show that the mass spectra of those hadrons are beautifully reproduced. We predict the masses of missing ground states, 1 meson and 20 baryons, which will be tested in the future experiment.
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