7,896 research outputs found

    Charm-strange baryon strong decays in a chiral quark model

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    The strong decays of charm-strange baryons up to N=2 shell are studied in a chiral quark model. The theoretical predictions for the well determined charm-strange baryons, Ξc∗(2645)\Xi_c^*(2645), Ξc(2790)\Xi_c(2790) and Ξc(2815)\Xi_c(2815), are in good agreement with the experimental data. This model is also extended to analyze the strong decays of the other newly observed charm-strange baryons Ξc(2930)\Xi_c(2930), Ξc(2980)\Xi_c(2980), Ξc(3055)\Xi_c(3055), Ξc(3080)\Xi_c(3080) and Ξc(3123)\Xi_c(3123). Our predictions are given as follows. (i) Ξc(2930)\Xi_c(2930) might be the first PP-wave excitation of Ξc′\Xi_c' with JP=1/2−J^P=1/2^-, favors the $|\Xi_c'\ ^2P_\lambda 1/2^->or or |\Xi_c'\ ^4P_\lambda 1/2^->state.(ii) state. (ii) \Xi_c(2980)mightcorrespondtotwooverlapping might correspond to two overlapping P−wavestates-wave states |\Xi_c'\ ^2P_\rho 1/2^->and and |\Xi_c'\ ^2P_\rho 3/2^->,respectively.The, respectively. The \Xi_c(2980)observedinthe observed in the \Lambda_c^+\bar{K}\pifinalstateismostlikelytobethe final state is most likely to be the |\Xi_c'\ ^2P_\rho 1/2^->state,whilethenarrowerresonancewithamass state, while the narrower resonance with a mass m\simeq 2.97GeVobservedinthe GeV observed in the \Xi_c^*(2645)\pichannelfavorstobeassignedtothe channel favors to be assigned to the |\Xi_c'\ ^2P_\rho 3/2^->state.(iii) state. (iii) \Xi_c(3080)favorstobeclassifiedasthe favors to be classified as the |\Xi_c\ S_{\rho\rho} 1/2^+>state,i.e.,thefirstradialexcitation(2S)of state, i.e., the first radial excitation (2S) of \Xi_c.(iv). (iv) \Xi_c(3055)ismostlikelytobethefirst is most likely to be the first D−waveexcitationof-wave excitation of \Xi_cwith with J^P=3/2^+,favorsthe, favors the |\Xi_c\ ^2D_{\lambda\lambda} 3/2^+>state.(v) state. (v) \Xi_c(3123)mightbeassignedtothe might be assigned to the |\Xi_c'\ ^4D_{\lambda\lambda} 3/2^+>,, |\Xi_c'\ ^4D_{\lambda\lambda} 5/2^+>,or, or |\Xi_c\ ^2D_{\rho\rho} 5/2^+>state.Asaby−product,wecalculatethestrongdecaysofthebottombaryons state. As a by-product, we calculate the strong decays of the bottom baryons \Sigma_b^{\pm},, \Sigma_b^{*\pm}and and \Xi_b^*$, which are in good agreement with the recent observations as well.Comment: 15 pages, 9 figure

    Clapeyron equation and phase equilibrium properties in higher dimensional charged topological dilaton AdS black holes with a nonlinear source

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    Using Maxwell's equal area law, we discuss the phase transition of higher dimensional charged topological dilaton AdS black holes with a nonlinear source. The coexisting region of the two phases is found and we depict the coexistence region in P−vP-v diagrams. The two-phase equilibrium curves in P−TP-T diagrams are plotted, and we take the first order approximation of volume vv in the calculation. To better compare with a general thermodynamic system, the Clapeyron equation is derived for higher dimensional charged topological black hole with a nonlinear source. The latent heat of isothermal phase transition is investigated. We also study the effect of the parameters of the black hole on the region of two-phases coexistence. The results show that the black hole may go through a small-large phase transition similar to those of usual non-gravity thermodynamic systems.Comment: 21 pages,25 figures. published version in EPJC. arXiv admin note: substantial text overlap with arXiv:1411.7202; text overlap with arXiv:1506.01786, arXiv:hep-th/0605042 by other author

    Solar system tests for realistic f(T)f(T) models with nonminimal torsion-matter coupling

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    In the previous paper, we have constructed two f(T)f(T) models with nonminimal torsion-matter coupling extension, which are successful in describing the evolution history of the Universe including the radiation-dominated era, the matter-dominated era, and the present accelerating expansion. Meantime, the significant advantage of these models is that they could avoid the cosmological constant problem of Λ\LambdaCDM. However, the nonminimal coupling between matter and torsion will affect the tests of Solar system. In this paper, we study the effects of Solar system in these models, including the gravitation redshift, geodetic effect and perihelion preccesion. We find that Model I can pass all three of the Solar system tests. For Model II, the parameter is constrained by the measure of the perihelion precession of Mercury.Comment: 10 page

    Thermodynamics of phase transition in higher dimensional Reissner-Nordstr\"{o}m-de Sitter black hole

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    It is well known that there are black hole and the cosmological horizons for the Reissner-Nordstr\"{o}m-de Sitter spacetime. Although the thermodynamic quantities on the horizons are not irrelevant, they satisfy the laws of black hole thermodynamics respectively. In this paper by considering the relations between the two horizons we give the effective thermodynamic quantities in (n+2)(n+2)-dimensional Reissner-Nordstr\"{o}m-de Sitter spacetime. The thermodynamic properties of these effective quantities are analyzed, moreover, the critical temperature, critical pressure and critical volume are obtained. We carry out an analytical check of Ehrenfest equations and prove that both Ehrenfest equations are satisfied. So the spacetime undergoes a second order phase transition at the critical point. This result is consistent with the nature of liquid--gas phase transition at the critical point, hence deepening the understanding of the analogy of charged dS spacetime and liquid--gas systems.Comment: 18 pages, 7 figures, 1 tabl

    Phase transition of the higher dimensional charged Gauss-Bonnet black hole in de Sitter spacetime

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    We study the phase transition of charged Gauss-Bonnet-de Sitter (GB-dS) black hole. For black holes in de Sitter spacetime, there is not only black hole horizon, but also the cosmological horizon. The thermodynamic quantities on the both horizons satisfy the first law of the black hole thermodynamics, respectively; moreover, there are additional connections between them. Using the effective temperature approach, we obtained the effective thermodynamic quantities of charged GB-dS black hole. According to Ehrenfest classification, we calculate some response functions and plot their figures, from which one can see that the spacetime undergoes a second-order phase transition at the critical point. It is shown that the critical values of effective temperature and pressure decrease with the increase of the value of GB parameter α\alpha.Comment: 9 pages, 16 figure

    Analgesic, anti-inflammatory and immuno-modulatory effects of dezocine-propofol anesthesia combination following colonoscopy

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    Purpose: To study and compare the analgesic, anti-inflammatory and immuno-modulatory effects of dezocine-propofol, and fentanyl-propofol combinations in colonoscopy.Methods: One hundred and thirty-four patients who received painless colonoscopy in Eastern Medical District of Linyi People's Hospital, Linyi City, Shandong Province, China, from June 2013 to December 2016 were randomly divided into two groups. Patients in the observation group (aged 42 - 65 years) received dezocine-propofol combination as anesthesia, while those in the control group (aged 41 - 67 years) were anesthetized with fentanyl-propofol. Serum levels of pain and inflammatory mediators, as well as contents of immune response molecules were determined prior to, during and after colonoscopy using either enzyme-linked immunosorbent assay (ELISA) or electro-chemiluminescence kits.Results: There were no statistically significant differences in the serum levels of 5-hydroxytryptophan (5-HTP), 5-hydroxy indole acetic acid (5-HIAA), substance P (SP), prostaglandin E2 (PGE2), C-reactive protein (CRP), heat shock protein 70 (HSP70), Interleukin-1 β(IL-1β), adrenocorticotropic hormone (ACTH), Cortisol (Cor), Inositol (Ins), c-peptide (C-P), immunoglobulin G (IgG) and immunoglobulin A (IgA), complement 3 (C3) and complement 4 (C4) before and during colonoscopy between the two groups of patients. However, after the examination, serum levels of 5-HTP, 5-HIAA, SP, PGE2, CRP, HSP70, IL-1 beta, ACTH, Cor, Ins and C-P in the observation group were significantly lower than those in control group (p < 0.05), while IgG, IgA, C3 and C4 contents were significantly higher than those of the control group (p < 0.05).Conclusion: These results suggest that the analgesic effect of dezocine-propofol combination after colonoscopy examination is superior to that of fentanyl-propofol combination, due to its effectiveness in inhibiting inflammatory reactions and improving immune response.Keywords: Colonoscopy, Dezocine, Propofol Fentanyl, Pain mediators, Analgesic, Inflammatory reaction, Immune respons
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