1,995 research outputs found

    Production of open-charm pentaquark molecules in decay B0Dˉ0ppˉB^0 \rightarrow \bar{D}^0 p \bar{p}

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    This study explores the production of open-charm pentaquark molecular states, specifically NDˉN\bar{D}^* and NˉDˉ\bar{N}\bar{D}^*, within the B0Dˉ0ppˉB^0 \rightarrow \bar{D}^0 p \bar{p} decay process. We analyze the invariant mass spectrum of pDˉ0p\bar{D}^0 and pˉDˉ0\bar{p}\bar{D}^0, incorporating the rescattering process calculated using a quasipotential Bethe-Salpeter equation approach. Our findings suggest the potential identification of the isoscalar NˉDˉ\bar{N}\bar{D}^* molecule with 3/2+3/2^+, serving as the antiparticle partner of the Λc(2940)\Lambda_c(2940), in the pˉDˉ0\bar{p}\bar{D}^0 mass distribution. Additionally, distinctive signals of the isovector NDˉN\bar{D}^* molecule with 1/21/2^- may emerge in the pDˉ0p\bar{D}^0 invariant mass distribution. We highlight the significance of the three-body decay of the bottom meson as a valuable avenue for studying open-charm molecules and advocate for increased attention and more precise experimental measurements of the B0Dˉ0ppˉB^0 \rightarrow \bar{D}^0 p \bar{p} process.Comment: 8 pages, 3 figure

    Hidden-bottom molecular states from Σb()B()ΛbB()\Sigma^{(*)}_bB^{(*)}-\Lambda_bB^{(*)} interaction

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    In this work, we study possible hidden-bottom molecular pentaquarks PbP_b from coupled-channel Σb()B()ΛbB()\Sigma^{(*)}_bB^{(*)}-\Lambda_bB^{(*)} interaction in the quasipotential Bethe-Salpeter equation approach. In isodoublet sector with I=1/2I=1/2, with the same reasonable parameters the interaction produces seven molecular states, a state near ΣbB \Sigma_bB threshold with spin parity JP=1/2J^P=1/2^-, a state near ΣbB\Sigma^*_bB threshold with 3/23/2^-, two states near ΣbB\Sigma_bB^* threshold with 1/21/2^- and 3/23/2^-, and three states near ΣbB\Sigma_b^*B^* threshold with 1/21/2^-, 3/23/2^-, and 5/25/2^-. The results suggest that three states near ΣbB\Sigma_b^* B^* threshold and two states near ΣbB\Sigma_b B^* threshold are very close, respectively, which may be difficult to distinguish in experiment without partial wave analysis. Compared with the hidden-charm pentaquark, the PbP_b states are relatively narrow with widths at an order of magnitude of 1 MeV or smaller. The importance of each channel considered is also discussed, and it is found that the ΛbB\Lambda_b B^* channel provides important contribution for the widths of those states. In isoquartet sector with I=3/2I=3/2, cutoff should be considerably enlarged to achieve bound states from the interaction, which makes the existence of such states unreliable. The results in the current work are helpful for searching for hidden-bottom molecular pentaquarks in future experiments, such as the COMPASS, J-PARC, and the Electron Ion Collider in China (EicC).Comment: 8 pages, 3 figure

    Possible molecular dibaryons with csssqqcsssqq quarks and their baryon-antibaryon partners

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    In this work, we systematically investigate the charmed-strange dibaryon systems with csssqqcsssqq quarks and their baryon-antibaryon partners from the interactions Ξc(,)Ξ()\Xi^{(',*)}_{c}\Xi^{(*)}, Ωc()Λ\Omega^{(*)}_c\Lambda, Ωc()Σ()\Omega^{(*)}_c\Sigma^{(*)}, ΛcΩ\Lambda_c\Omega and Σc()Ω\Sigma^{(*)}_c\Omega and their baryon-antibaryon partners from interactions Ξc(,)Ξˉ()\Xi^{(',*)}_{c}\bar{\Xi}^{(*)}, Ωc()Λˉ\Omega^{(*)}_c\bar{\Lambda}, Ωc()Σˉ()\Omega^{(*)}_c\bar{\Sigma}^{(*)}, ΛcΩˉ\Lambda_c\bar{\Omega} and Σc()Ωˉ\Sigma^{(*)}_c\bar{\Omega}. The potential kernels are constructed with the help of effective Lagrangians under SU(3), heavy quark, and chiral symmetries to describe these interactions. To search for possible molecular states, the kernels are inserted into the quasipotential Bethe-Salpeter equation, which is solved to find poles from scattering amplitude. The results suggest that 36 and 24 bound states can be found in the baryon-baryon and baryon-antibaryon interactions, respectively. However, much large values of parameter α\alpha are required to produce the bound states from the baryon-antibaryon interactions, which questions the existence of these bound states. Possible coupled-channel effect are considered in the current work to estimate the couplings of the molecular states to the channels considered.Comment: 13 pages, 5 figures. arXiv admin note: text overlap with arXiv:2208.1196

    Extraordinary focusing of sound above a soda can array without time reversal

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    Recently, Lemoult et al. [Phys. Rev. Lett. 107, 064301 (2011)] used time reversal to focus sound above an array of soda cans into a spot much smaller than the acoustic wavelength in air. In this study, we show that equally sharp focusing can be achieved without time reversal, by arranging transducers around a nearly circular array of soda cans. The size of the focal spot at the center of the array is made progressively smaller as the frequency approaches the Helmholtz resonance frequency of a can from below, and, near the resonance, becomes smaller than the size of a single can. We show that the locally resonant metamaterial formed by soda cans supports a guided wave at frequencies below the Helmholtz resonance frequency. The small focal spot results from a small wavelength of this guided wave near the resonance in combination with a near field effect making the acoustic field concentrate at the opening of a can. The focusing is achieved with propagating rather than evanescent waves. No sub-diffraction-limited focusing is observed if the diffraction limit is defined with respect to the wavelength of the guided mode in the metamaterial medium rather than the wavelength of the bulk wave in air

    Possible molecular states from interactions of charmed baryons

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    In this work, we perform a systematic study of possible molecular states composed of two charmed baryons including hidden-charm systems ΛcΛˉc\Lambda_c\bar{\Lambda}_c, Σc()Σˉc()\Sigma_c^{(*)}\bar{\Sigma}_c^{(*)}, and ΛcΣˉc()\Lambda_c\bar{\Sigma}_c^{(*)}, and corresponding double-charm systems ΛcΛc\Lambda_c\Lambda_c, Σc()Σc()\Sigma_c^{(*)}\Sigma_c^{(*)}, and ΛcΣc()\Lambda_c\Sigma_c^{(*)}. With the help of the heavy quark chiral effective Lagrangians, the interactions are described with π\pi, ρ\rho, η\eta, ω\omega, ϕ\phi, and σ\sigma exchanges. The potential kernels are constructed, and inserted into the quasipotential Bethe-Salpeter equation. The bound states from the interactions considered is studied by searching for the poles of the scattering amplitude. The results suggest that strong attractions exist in both hidden-charm and double-charm systems considered in the current work, and bound states can be produced in most of the systems. More experiment studies about these molecular states are suggested though the nucleon-nucleon collison at LHC and nucleon-antinucleon collison at PˉANDA\rm \bar{P}ANDA.Comment: 7 pages, 5 figure

    Effects of STAT3 Gene Silencing and Rapamycin on Apoptosis in Hepatocarcinoma Cells

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    The PI3K/Akt/mTOR and JAK/STAT3 signaling pathways are important for regulating apoptosis, and are frequently activated in cancers. In this study, we targeted STAT3 and mTOR in human hepatocellular carcinoma Bel-7402 cells and examined the subsequent alterations in cellular apoptosis. The expression of STAT3 was silenced with small interfering RNA (siRNA)-expressing plasmid. The activity of mTOR was inhibited using rapamycin. Following treatment, Annexin V/propidium iodide staining followed by flow cytometry and Hoechst33258 immunofluorescence staining was used to examine cellular apoptosis. JC-1 staining was used to monitor depolarization of mitochondrial membrane (ΔΨm). Furthermore, the expression of activated caspase 3 protein was analyzed by Western blotting. Compared to non-treated or control siRNA-transfected cells, significantly higher levels of apoptosis were detected in siSTAT3-transfected or rapamycin-treated cells (P < 0.05), which was further enhanced in cells targeted for both molecules (P < 0.05). The pro-apoptotic effects were accompanied with concomitant depolarization of mitochondrial membrane and up-regulation of activated caspase 3. Combined treatments using rapamycin and STAT3 gene silencing significantly increases apoptosis in Bel-7402 cells, displaying more dramatic effect than any single treatment. This study provides evidence for targeting multiple molecules in cancer therapy

    Introduction to the wheelchair training's influence on the rehabilitation of patients

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    目的  通过轮椅训练提高患者掌握轮椅的技巧,保证患者乘坐轮椅时的安全,提高患者日常生活能力及社会参与能力。方法  通过轮椅基本技术动作练习、轮椅技巧动作训练、轮椅体育项目训练、社会实践检测。结果  患者轮椅训练前后对照,躯干的控制能力较前好转,ADL能力明显提高,社会参与能力增强。结论  轮椅训练可以使残疾人参与康复体育和社会活动的机会明显增加。Objective: Training to improve patient’s master of wheelchair technology to ensure the safety of patients in wheelchairs things to improve patients' daily living skills and social participation skills. Methods: By practicing basic techniques wheelchair, wheelchair technology movement training, wheelchair sports training, social practice test. Results: Wheelchair patients before and after control technology, the ability to control the trunk before it gets better, ADL ability as well as social participation improved significantly. Conclusion: Wheelchair training increased opportunities for people with disabilities to participate in the rehabilitation of sports and social activities.
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