6,572 research outputs found
Search for C-Parity Violation in J/ψ → γγ and γϕ
No full textUsing 1.06 x 10⁸ ψ(3686) events recorded in e⁺e⁻ collisions at √s = 3.686 GeV with the BESIII at the BEPCII collider, we present searches for C-parity violation in J/ψ → γγ and γϕ decays via ψ(3686) → J/ψ π⁺π⁻. No significant signals are observed in either channel. Upper limits on the branching fractions are set to be ℬ(J/ψ → γγ) < 2.7 x 10⁻⁷ and ℬ(J/ψ → γϕ) < 1.4 x 10⁻⁶ at the 90% confidence level. The former is one order of magnitude more stringent than the previous upper limit, and the latter represents the first limit on this decay channel.National Key Basic Research Program of China (2015CB856700); Joint Funds of the National Natural Science Foundation of China (11079008, 11179007, U1232201, U1332201); National Natural Science Foundation of China (NSFC) (11205082, 11475090, 10935007, 11121092, 11125525, 11235011, 11322544, 11335008); Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program (KJCX2-YW-N29, KJCX2-YW-N45); German Research Foundation DFG under Contract No. Collaborative Research Center (CRC-1044); Ministry of Development of Turkey (DPT2006K-120470); Russian Foundation for Basic Research (14-07-91152); US Department of Energy (DE-FG02-04ER41291, DE-FG02-05ER41374, DE-FG02-94ER40823, DESC0010118); WCU Program of the National Research Foundation of Korea (32-2008-000-10155-0)
Searches for Isospin-Violating Transitions χ_{c0,2} → π⁰η_c.
No full textWe present the first upper-limit measurement of the branching fractions of the isospin-violating transitions χ{c0,2} → π⁰η{c}. The measurements are performed using 106 x 10⁶ ψ(3686) events accumulated with the BESIII detector at the BEPCII e⁺e⁻ collider at a center-of-mass energy corresponding to the ψ(3686) mass. We obtained upper limits on the branching fractions at a 90% confidence level of B(χ{c0,2} → π⁰η{c}) < 3.2 x 10⁻³
An Improved Limit for Γ_{ee} of X(3872) and Γ_{ee} Measurement of ψ(3686)
No full textUsing the data sets taken at center-of-mass energies above 4 GeV by the BESIII detector at the BEPCII storage ring, we search for the reaction e⁺e⁻→ γ(ISR}X(3872) → γ{ISR}π⁺π⁻J/ψ via the Initial State Radiation technique. The production of a resonance with quantum numbers JPC=1⁺⁺ such as the X(3872) via single photon e+e- annihilation is forbidden, but is allowed by a next-to-leading order box diagram. We do not observe a significant signal of X(3872), and therefore give an upper limit for the electronic width times the branching fraction Γ{ee} ^{X(3872)} ℬ(X(3872) → π⁺π⁻J/ψ) < 0.13 eV at the 90% confidence level. This measurement improves upon existing limits by a factor of 46. Using the same final state, we also measure the electronic width of the ψ(3686) to be Γ {ee} ^{ψ(3686)} = 2213 ± 18{stat} ± 99{sys} eV. © 2015 The Authors.National Key Basic Research Program of China (Contract no.2015CB856700); National Natural Science Foundation of China (NSFC) (Contract nos..11125525, 11235011, 11322544, 11335008, 11425524); Joint Large-Scale Scientific Facility Funds of the NSFC and CAS (contract nos. 11179007, U1232201, U1332201); CAS (contract nos. KJCX2-YW-N29, KJCX2-YW-N45); German Research Foundation DFG (contract no. CRC-1044); Seventh Framework Programme of the European Union under Marie Curie International Incoming Fellowship Grant (agreement no. 627240; Ministry of Development of Turkey (contract no. DPT2006K-120470); Russian Foundation for Basic Research (contract no. 14-07-91152); U.S. Department of Energy (contract nos. DE-FG02-04ER41291, DE-FG02-05ER41374, DE-FG02-94ER40823, DESC0010118); WCU Program of National Research Foundation of Korea (contract no. R32-2008-000-10155-0)
Liver mitochondrial properties from the obesity-resistant Lou/C rat.
No full textInternational audienceOBJECTIVE: The first objective was to evaluate the influence of caloric intake on liver mitochondrial properties. The second objective was aimed at determining the impact of increasing fat intake on these properties. DESIGN: Lou/C rats, displaying an inborn low caloric intake and resistant to diet-induced obesity, were compared to Wistar rats fed either ad libitum or pair-fed. An additional group of Lou/C rats were allowed to increase their fat intake by adjusting their diet from a standard high carbohydrate low-fat diet to a high-fat carbohydrate-free diet. MEASUREMENTS: Hydrogen peroxide (H(2)O(2)) generation, oxygen consumption rate (J(O(2))), membrane potential (DeltaPsi), activity of respiratory chain complexes, cytochrome contents, oxidative phosphorylation efficiency (OPE) and uncoupling protein 2 (UCP2) expression were determined in liver mitochondria. RESULTS: H(2)O(2) production was higher in Lou/C than Wistar rats with glutamate/malate and/or succinate, octanoyl-carnitine, as substrates. These mitochondrial features cannot be mimicked by pair-feeding Wistar rats and remained unaltered by increasing fat intake. Enhanced H(2)O(2) production by mitochondria from Lou/C rats is due to an increased reverse electron flow through the respiratory-chain complex I and a higher medium-chain acyl-CoA dehydrogenase activity. While J(O(2)) was similar over a large range of DeltaPsi in both strains, Lou/C rats were able to sustain higher membrane potential and respiratory rate. In addition, mitochondria from Lou/C rats displayed a decrease in OPE that cannot be explained by increased expression of UCP2 but rather to a slip in proton pumping by cytochrome oxidase. CONCLUSIONS: Liver mitochondria from Lou/C rats display higher reactive oxygen species (ROS) generation but to deplete upstream electron-rich intermediates responsible for ROS generation, these animals increased intrinsic uncoupling of cytochrome oxidase. It is likely that liver mitochondrial properties allowed this strain of rat to display higher insulin sensitivity and resist diet-induced obesity
Monte Carlo study of particle identification at the CEPC using TPC dE / dx information
No full textAbstract The kaon identification is crucial for the flavor physics, and also benefits the flavor and charge reconstruction of the jets. We explore the particle identification capability for tracks with momenta ranging from 2–20 GeV/c using the dE / dx measurements in the Time Projection Chamber at the future Circular Electron-Positron Collider. Based on Monte Carlo simulation, we anticipate that an average 3.2σ ( 2.6σ ) K/π separation can be achieved based on dE / dx information for an optimistic (conservative) extrapolation of the simulated performance to the final system. Time-of-flight (TOF) information from the Electromagnetic Calorimeter can provide K/π separation around 1 GeV/c and reduce the K / p mis-identification rate. By combining the dE / dx and TOF information, we estimate that in the optimistic scenario a kaon selection in inclusive hadronic Z decays with both the average efficiency and purity approaching 95% can be achieved
Measurement of the Absolute Branching Fraction of the Inclusive Decay Lambda(+)(c) -> Lambda plus X
No full textBased on an e(+)e(-) collision data sample corresponding to an integrated luminosity of 567 pb(-1) taken at the center-of-mass energy of root s = 4.6 GeV with the BESIII detector, we measure the absolute branching fraction of the inclusive decay Lambda(+)(c) -> Lambda + X to be B(Lambda(+)(c) -> Lambda + X) = (38.2(-2.2)(+2.8) +/- 0.9)% using the double-tag method, where X refers to any possible final state particles. In addition, we search for direct CP violation in the charge asymmetry of this inclusive decay for the first time, and obtain A(CP) [B(Lambda(+)(c) -> Lambda + X) - B((Lambda) over bar (-)(c) -> (Lambda) over bar + X)]/[B(Lambda(+)(c) -> Lambda + X) + B((Lambda) over bar (-)(c) -> (Lambda) over bar + X)] = (2.1(-6.6)(+7.0) +/- 1.6)%, a statistically limited result with no evidence of CP violation
Lack of starvation-induced activation of AMP-activated protein kinase in the hypothalamus of the Lou/C rats resistant to obesity.
No full textOBJECTIVE: The AMP-activated protein kinase (AMPK) is involved in the control of food intake by the hypothalamus. The aim of this work was to investigate if modification of hypothalamic AMPK regulation could be related to the spontaneous food restriction of Lou/C rats, a strain resistant to obesity exhibiting a 40% reduction in caloric intake compared with their lean Wistar counterparts. DESIGN: Three-month-old male Lou/C rats were compared with age-matched male Wistar rats in both fed ad libitum and 24-h food deprivation state. MEASUREMENTS AND RESULTS: We first confirmed that starvation activated both isoforms of AMPK catalytic alpha subunits and enhanced the phosphorylation state of its downstream targets acetyl-CoA carboxylase and elongation factor 2 in the hypothalamus of Wistar rats. These changes were not observed in the hypothalamus of Lou/C rats. Interestingly, the starvation-induced changes in hypothalamic mRNA levels of the main orexigenic and anorexigenic neuropeptides were also blunted in the Lou/C rats. Analysis of the concentrations of circulating substrates and hormones known to regulate hypothalamic AMPK indicated that the starvation-induced changes in ghrelin, adiponectin and leptin were not observed in Lou/C rats. Furthermore, an increased phosphorylation state of signal transducer and activator of transcription 3 (STAT3), which admittedly mediates leptin signaling, was evidenced in the hypothalamus of the starved Lou/C rats, as well as modifications of expression of the leptin-sensitive genes suppressor of cytokine signaling-3 and stearoyl-coenzyme A desaturase 1. In addition, despite reduced leptin level in fed Lou/C rats, the phosphorylation state of hypothalamic STAT3 remained similar to that found in fed Wistar rats, an adaptation that could be explained by the concomitant increase in ObRb leptin receptor mRNA expression. CONCLUSION: Activation of hypothalamic AMPK by starvation, which stimulates food intake through changes in (an)orexigenic neuropeptides in the normal rats, was not observed in the spontaneously hypophagic Lou/C rats
Study of η(1475) and Χ(1835) in Radiative J/ψ Decays to γφ
No full textThe decay J/ψ → γγφ is studied using a sample of 1.31 x 10⁹ J/ψ events collected with the BESIII detector. Two structures around 1475 MeV/c² and 1835 MeV/c² are observed in the γφ invariant mass spectrum for the first time. With a fit on the γφ invariant mass, which takes into account the interference between the two structures, and a simple analysis of the angular distribution, the structure around 1475 MeV/c² is found to favor an assignment as the η(1475) and the mass and width for the structure around 1835 MeV/c² are consistent with the X(1835). The statistical significances of the two structures are 13.5σ and 6.3σ, respectively. The results indicate that both η(1475) and X(1835) contain a sizeable ss̅ component.School of Natural Sciences and Mathematic
PENGARUH PAKAN IKAN LOU HAN YANG BEREDAR DI PASARAN TERHADAP PERTUMBUHAN DAN PERUBAHAN WARNA. LOU HAN RED DIAMOND
No full textLou Han merupakan salah satu ikan hias yang banyak digemari di Indonesia dan berasal dari keluarga Cichlidae. Siklid merupakan keluarga besar yang terdiri atas ratusan spesies. Perkawinan silang antar Lou Han terbukti menghasilkan Lou Han yang cukup baik kualitasnya dengan ciri-ciri fisik tertentu, yaitu pada aspek warna, rajah dan keindahan bentuk. Salah satu faktor yang berpengaruh terhadap perubahan warna ikan Lou Han adalah dengan pemberian pakan buatan di samping faktor genetic ikan tersebut. Terdapat banyak produk pakan Lou Han yang beredar di pasaran dan menawarkan keunggulan masing-masing antara lain untuk pertumbuhan, perubahan warna, perkembangan nonong dan penampakan sisik mutiara, sehingga membuat bingung konsumen untuk memilihnya. Terdapat juga strategi pasar yang membuat pakan yang dwifungsi atau tiga fungsi. Penelitian ini dilakukan untuk menguji berbagai merk pakan Lou Han yang beredar di pasaran terhadap perubahan warna khususnya warna merah pada ikan Lou Han Red Diamond, di samping itu untuk mengetahui pertumbuhan (pertambahan berat badan) ikan. Penelitian ini menggunakan Rancangan Acak Lengkap dengan 4 macam perlakuan pakan dan 4 ulangan. Masing-masing ulangan berisi 5 ekor ikan Lou Han. Adapun 4 macam perlakuan pakan lou han tersebut adalah Z (A), FH (B), A (C) dan HF (D). Pakan diberikan sebanyak 3 x sehari yaitu pada pagi, siang dan sore hari selama 4 minggu. Variabel yang diamati adalah pertambahan berat badan per-hari serta perubahan warna pada akhir penelitian. Rata-rata pertambahan berat badan per-hari ikan lou han dengan pemberian beberapa merk pakan komersial adalah : pakan A sebesar 0,1550 gram, pakan B sebesar 0,1846 gram, pakan C sebesar 0,1423 gram dan pakan D sebesar 0,1626 gram. Uji anava menunjukkan tidak adanya perbedaan yang nyata pada keempat perlakuan. Rata-rata skala warna ikan lou han pada akhir penelitian dengan pemberian beberapa merk pakan komersial adalah : pakan A skala 2 , pakan B skala 1,75 , pakan C skala 2,75 dan pakan D skala 3,25. Uji Kruskal Wallis dan uji Z menunjukkan bahwa pakan D berbeda nyata dengan pakan A dan B namun tidak berbeda nyata dengan pakan C. Pakan A tidak berbeda nyata dengan pakan B, namun berbeda nyata dengan pakan C dan D. Saran yang bisa diberikan dari hasil penelitian ini adalah hendaknya hobiis dalam membeli pakan untuk ikan Lou Han sebaiknya memeriksa terlebih dahulu kadar nutrisi yang sesuai dengan kebutuhan ikan dan sumber pigmen warnanya, meskipun harganya relatif mahal
Measurement of the absolute branching fraction of the inclusive decay Λ ̄c− →n ̄+X
No full textBased on e+e− collision data corresponding to an integrated luminosity of 4.5 fb−1 collected at the center-of-mass energies between 4.600 and 4.699 GeV with the BESIII detector at BEPCII, the absolute branchingfractionoftheinclusivedecayΛ ̄−c →nbar+X,where X refers to any possible final state particles, is measured. The absolute branching fraction is determined to be B(Λ ̄−c →nbar+X)=(32.4 pm 0.7 pm 1.5)%, where the first uncertainty is statistical and the second systematic. Assuming CP symmetry, the measurement indicates that about one fourth of Λ+c (Λ ̄−c) decay modes with a neutron(anantineutron) in the final state have not been observe
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