3,166 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=1/2J^P=1/2^-, favors the $|\Xi_c'\ ^2P_\lambda 1/2^->or or |\Xi_c'\ ^4P_\lambda 1/2^->state.(ii) state. (ii) \Xi_c(2980)mightcorrespondtotwooverlapping might correspond to two overlapping Pwavestates-wave states |\Xi_c'\ ^2P_\rho 1/2^->and and |\Xi_c'\ ^2P_\rho 3/2^->,respectively.The, respectively. The \Xi_c(2980)observedinthe observed in the \Lambda_c^+\bar{K}\pifinalstateismostlikelytobethe final state is most likely to be the |\Xi_c'\ ^2P_\rho 1/2^->state,whilethenarrowerresonancewithamass state, while the narrower resonance with a mass m\simeq 2.97GeVobservedinthe GeV observed in the \Xi_c^*(2645)\pichannelfavorstobeassignedtothe channel favors to be assigned to the |\Xi_c'\ ^2P_\rho 3/2^->state.(iii) state. (iii) \Xi_c(3080)favorstobeclassifiedasthe favors to be classified as the |\Xi_c\ S_{\rho\rho} 1/2^+>state,i.e.,thefirstradialexcitation(2S)of state, i.e., the first radial excitation (2S) of \Xi_c.(iv). (iv) \Xi_c(3055)ismostlikelytobethefirst is most likely to be the first Dwaveexcitationof-wave excitation of \Xi_cwith with J^P=3/2^+,favorsthe, favors the |\Xi_c\ ^2D_{\lambda\lambda} 3/2^+>state.(v) state. (v) \Xi_c(3123)mightbeassignedtothe might be assigned to the |\Xi_c'\ ^4D_{\lambda\lambda} 3/2^+>,, |\Xi_c'\ ^4D_{\lambda\lambda} 5/2^+>,or, or |\Xi_c\ ^2D_{\rho\rho} 5/2^+>state.Asabyproduct,wecalculatethestrongdecaysofthebottombaryons state. As a by-product, we calculate the strong decays of the bottom baryons \Sigma_b^{\pm},, \Sigma_b^{*\pm}and and \Xi_b^*$, which are in good agreement with the recent observations as well.Comment: 15 pages, 9 figure

    Effect of High Se and Co Alfalfa Forage on Animal Production

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    Total and available selenium (Se) and cobalt (Co) concentrations are low in Chinese soils, especially those found in mainly in temperate humid sub-humid conditions in the northeast to the southwest band across China (Tan et al. 2002). The levels of Se and Co are marginally deficit in the brown soil of the Yellow River region which causes lower production level and quality in forage and crop plants. Application of Se and Co fertilizers to arable lands is essential to produce high Se and Co forages. Henan is a Province where produce high-quality grass forages are used to support dairy farming. The province is mainly spread along the Yellow River where soils are sandy and deficient in Se and Co (Lu et al. 2003). Se deficiency in forages not only limits livestock production, but also affects the quality and safety of food products (Rotruck et al. 2003). Since rabbits and dairy cows are especially sensitive to low Se levels in feed, we chose these as our test animals. The objective of this study was to analyze effect of high Se and Co alfalfa forage on animal production and feed conversion efficiency in order to establish a set of effective technical ways to solve trace element gaps of animal diets, i.e. by basal fertilization of Se and Co fertilizers in soil. This study was conducted as a series of field trials and animal experiments from 2007 to 2008

    Leptophilic dark matter in gauged U(1)LeLμU(1)_{L_e-L_\mu} model in light of DAMPE cosmic ray e++ee^+ + e^- excess

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    Motivated by the very recent cosmic-ray electron+positron excess observed by DAMPE collaboration, we investigate a Dirac fermion dark matter (DM) in the gauged LeLμL_e - L_\mu model. DM interacts with the electron and muon via the U(1)eμU(1)_{e-\mu} gauge boson ZZ^{'}. The model can explain the DAMPE data well. Although a non-zero DM-nucleon cross section is only generated at one loop level and there is a partial cancellation between ZeeZ^{'}ee and ZμμZ^{'}\mu\mu couplings, we find that a large portion of ZZ^{'} mass is ruled out from direct DM detection limit leaving the allowed ZZ^{'} mass to be close to two times of the DM mass. Implications for ppZ2pp \to Z^{'} \to 2\ell and pp2+Zpp \to 2\ell + Z^{'} , and muon g2g-2 anomaly are also studied.Comment: Discussions added, version accepted by EPJ

    Effects of Se and Co Combined Fertilizer on Production of Alfalfa

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    Selenium(Se) and cobalt (Co) are important essential trace elements for forage and animal production (Yang et al. 1998, Arvy 1993). The supplementation of Se in animal diet significantly increases Se-Glutathione peroxidase (GSH-Px ) activities in the liver, testes, spermatozoa and seminal plasma (Abdelrahman et al.1998), Selenium is also a key component of a number of functional seleno-proteins. GSH-Px is the best characterized of the family of selenoproteins. In Henan Province, the fine grass and green milk production zones are mainly distributed along the riverbank of the Yellow River where soils are sandy and sterile with lower Se and Co contents (Lu et al. 2003). Deficiency of Se and Co in soils affects local forage and animal production level, as well as the qualities and securities of fodder and animal products (Rotruck et al. 2003). This experiment was carried out to determine the impacts of the application combined Se and Co on the quality of alfalfa hay

    Effects of Pharmacological Block of GABAA Receptors on Pallidal Neurons in Normal and Parkinsonian State

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    The globus pallidus plays a central integrative role in the basal ganglia circuitry. Morphological studies have revealed a high level of GABA and GABAA receptors in the globus pallidus. To further investigate the effects of endogenous GABAA neurotransmission in the globus pallidus of normal and parkinsonian rats, in vivo extracellular recording and behavioral tests were performed in the present studies. In normal rats, micro-pressure ejection of GABAA receptor antagonist gabazine (0.1 mM) increased the spontaneous firing rate of pallidal neurons by 28.3%. Furthermore, in 6-hydroxydopamine parkinsonian rats, gabazine increased the firing rate by 46.0% on the lesioned side, which was significantly greater than that on the unlesioned side (21.5%, P < 0.05), as well as that in normal rats (P < 0.05). In the behaving rats, unilateral microinjection of gabazine (0.1 mM) evoked consistent contralateral rotation in normal rats, and significantly potentiated the number of apomorphine-induced contralateral rotations in parkinsonian rats. The present electrophysiological and behavioral findings may provide a rational for further investigations into the potential of pallidal endogenous GABAA neurotransmission in the treatment of Parkinson's disease

    Effect of the chosen incision on corneal astigmatism after implantable collamer lens surgery

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    AIM: To evaluate the effect of the chosen incision on corneal astigmatism after implantable collamer lens(ICL)surgery.<p>METHODS: The study included 195 eyes of 102 patients, and all eyes were randomly divided into two groups: the chosen incision group(Group A, 97 eyes)and temporal corneal incision(Group B, 98 eyes). Before the operation, and 1wk,1mo and 3mo after the operation, each patient was examined with corneal topography to observe the changes of corneal astigmatism. <p>RESULTS: Preoperative corneal astigmatisms were(1.26±0.35)D in group A and(1.28±0.38)D in group B, thus there was no statistically significant difference(<i>P</i>>0.05). One week postoperatively, the astigmatism were(0.93±0.29)D in group A and(1.32±0.33)D in group B. One month postoperatively, the astigmatism were(0.85±0.16)D in group A and(1.27±0.18)D in group B. Three months postoperatively, the astigmatism were(0.80±0.13)D in group A and(1.25±0.20)D in group B. The differences between the two groups were statistically significant(<i>P</i><0.01). <p>CONCLUSION: The chosen incision can reduce postoperative astigmatism to a certain extent after ICL surgery
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