2,261 research outputs found
Effects of states and bottom meson loops on transitions
We study the dipion transitions . In particular, we consider the effects of the two
intermediate bottomoniumlike exotic states and as
well as bottom meson loops. The strong pion-pion final-state interactions,
especially including channel coupling to in the -wave, are taken
into account model-independently by using dispersion theory. Based on a
nonrelativistic effective field theory we find that the contribution from the
bottom meson loops is comparable to those from the chiral contact terms and the
-exchange terms. For the decay, the result shows that including the effects of the
-exchange and the bottom meson loops can naturally reproduce the two-hump
behavior of the mass spectra. Future angular distribution data are
decisive for the identification of different production mechanisms. For the
decay, we show that there is
a narrow dip around 1 GeV in the invariant mass distribution, caused
by the final-state interactions. The distribution is clearly different from
that in similar transitions from lower states, and needs to be
verified by future data with high statistics. Also we predict the decay width
and the dikaon mass distribution of the process.Comment: 25 pages, 8 figures, predictions of the decay width and the dikaon
mass distribution of the
process added, more discussions adde
Revealing the mystery of the double charm tetraquark in collision
A novel approach is proposed to probe the nature of the double charm
tetraquark through the measurement of production asymmetry between
and in collisions. When comparing two
theoretical pictures, the compact tetraquark and molecular pictures, we find
that the compact tetraquark picture exhibits a significantly larger production
asymmetry and an order of magnitude lower total cross section compared to the
molecular picture, enabling the unambiguous determination of the tetraquark's
internal structure. Additionally, distinctive differences in the transverse
momentum () and rapidity () distributions of
and cross sections emerge, particularly at
and . The difference
between particles and antiparticles in a large rapidity region is attributed to
the behavior of the residual diquarks within the proton. Our work extends
to the exploration of other double heavy tetraquark candidates, offering a
versatile approach to advance our understanding of exotic hadronic states in
particle physics.Comment: 6 pages, 3 figure
Survivin is a prognostic marker and therapeutic target for extranodal, nasal-type natural killer/T cell lymphoma.
Background: The relationship between survivin and extranodal, nasal-type natural killer/T cell lymphoma (ENKTCL) was unclearly established yet. We here studied the potential prognostic roles of survivin and its implication as a target in ENKTCL therapy.
Methods: ENKTCL patients\u27 peripheral blood were collected and tested by ELISA. ENKTCL cell lines were cultured with or without survivin inhibitor and tested by MTT and Flow cytometry. According to the gene expression profiles from the ArrayExpress Archive under E-TABM-702, survivin co-regulated cluster was established by Coupled Two-way Clustering Algorithm.
Results: Seventeen point six percent of total 17 ENKTCL patients were serum survivin-positive. These patients had poorer outcome than that of negative cases (P
Conclusions: We concluded that survivin was a potential prognostic marker and a critical regulatory molecule in the pathological process of ENKTCL. It would be a promising target in drugs discovery for ENKTCL therapy
Deep quantum neural networks equipped with backpropagation on a superconducting processor
Deep learning and quantum computing have achieved dramatic progresses in
recent years. The interplay between these two fast-growing fields gives rise to
a new research frontier of quantum machine learning. In this work, we report
the first experimental demonstration of training deep quantum neural networks
via the backpropagation algorithm with a six-qubit programmable superconducting
processor. In particular, we show that three-layer deep quantum neural networks
can be trained efficiently to learn two-qubit quantum channels with a mean
fidelity up to 96.0% and the ground state energy of molecular hydrogen with an
accuracy up to 93.3% compared to the theoretical value. In addition, six-layer
deep quantum neural networks can be trained in a similar fashion to achieve a
mean fidelity up to 94.8% for learning single-qubit quantum channels. Our
experimental results explicitly showcase the advantages of deep quantum neural
networks, including quantum analogue of the backpropagation algorithm and less
stringent coherence-time requirement for their constituting physical qubits,
thus providing a valuable guide for quantum machine learning applications with
both near-term and future quantum devices.Comment: 7 pages (main text) + 11 pages (Supplementary Information), 10
figure
Dirac semimetal PdTe2 temperature-dependent quasiparticle dynamics and electron-phonon coupling
Dirac semimetal PdTe2 single-crystal temperature-dependent ultrafast carrier
and phonon dynamics were studied using ultrafast optical pump-probe
spectroscopy. Two distinct carrier and coherent phonons relaxation processes
were identified in the 5 K - 300 K range. Quantitative analysis revealed a fast
relaxation process ({\tau}_f) occurring on a subpicosecond time scale which
originated from electron-phonon thermalization. This was followed by a slower
relaxation process ({\tau}_s) with a time scale of ~ 7-9.5 ps which originated
from phonon-assisted electron-hole recombination. Two significant vibrational
modes resolved at all measured temperatures and corresponded to Te atoms
in-plane (E_g), and out-of-plane (A_1g), motion. As temperature increased both
phonon modes softened markedly. A_1g mode frequency monotonically decreased as
temperature increased. Its damping rate remained virtually unchanged. As
expected, E_g decreased uniformly as temperatures rose. At temperatures above
80 K, there was insignificant change. Test results suggested that pure
dephasing played an important role in the relaxation processes. PdTe2 phonon is
thought responsible for its superconductive properties. Examining phonons
behavior should improve the understanding of its complex superconductivity.Comment: 6 pages, 4 figure
Expression and Role of the Calcium-Sensing Receptor in Rat Peripheral Blood Polymorphonuclear Neutrophils
The calcium-sensing receptors (CaSRs) play an important role in many tissues and organs that are involved in inflammatory reactions. Peripheral blood polymorphonuclear neutrophils (PMNs) are important inflammatory cells. However, the expression and functions of CaSR in peripheral blood PMNs are still not reported. In this study, we collected rat peripheral blood PMNs to observe the relationship between CaSR and PMNs. From the results, we found first that the CaSR protein was expressed in PMNs, and it increased after PMNs were activated with fMLP. In addition, CaSR activator cincalcet promoted the expression of CaSR and P-p65 (NF-κB signaling pathway protein) and Bcl-xl (antiapoptosis protein), and it increased the secretion of interleukin-6 (IL-6) and myeloperoxidase (MPO); meanwhile, it decreased proapoptosis protein Bax expression and the production of IL-10 and reactive oxygen species (ROS). At the same time, cincalcet also decreased the PMN apoptosis rate analyzed by flow cytometry. However, CaSR inhibitor NPS-2143 and NF-κB signaling pathway inhibitor PDTC reverse the results cited earlier. All of these results indicated that CaSR can regulate PMN functions and status to play a role in inflammation, which is probably through the NF-κB signaling pathway
The Hidden Nematic Fluctuations in the Triclinic (Ca0.85La0.15)10(Pt3As8)(Fe2As2)5 Superconductor Revealed by Ultrafast Optical Spectroscopy
We reported the quasiparticle relaxation dynamics of an optimally doped
triclinic iron-based superconductor
(CaLa)(PtAs)(FeAs) with bulk
= 30 K using polarized ultrafast optical pump-probe spectroscopy. Our results
reveal anisotropic transient reflectivity induced by nematic fluctuations
develops below 120 K and persists in the superconducting
states. Measurements under high pump fluence reveal three distinct, coherent
phonon modes at frequencies of 1.6, 3.5, and 4.7 THz, corresponding to
, , and modes, respectively. The high-frequency
mode corresponds to the -axis polarized vibrations of FeAs
planes with a nominal electron-phonon coupling constant
0.139 0.02. Our findings suggest that the superconductivity and
nematic state are compatible but competitive at low temperatures, and the
phonons play an important role in the formation of Cooper pairs in
(CaLa)(PtAs)(FeAs).Comment: 6 pages, 3 figures and Supplemental Material
Nesting-driven antiferromagnetic order in Kondo lattice CePd5Al2
We investigated the electronic structure of the antiferromagnetic Kondo
lattice CePd5Al2 using high-resolution angle-resolved photoemission
spectroscopy. The experimentally determined band structure of the conduction
electrons is predominated by the Pd 4d character. It contains multiple hole and
electron Fermi pockets, in good agreement with density functional theory
calculations. The Fermi surface is folded over Q0 = (0, 0, 1), manifested by
Fermi surface reconstruction and band folding. Our results suggest that Fermi
surface nesting drives the formation of antiferromagnetic order in CePd5Al2.Comment: 6 pages,3 figur
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