3,514 research outputs found

    Observation of Two Resonant Structures in e+e- to pi+ pi- psi(2S) via Initial State Radiation at Belle

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    The cross section for e+e- to pi+ pi- psi(2S) between threshold and \sqrt{s}=5.5 GeV is measured using 673 fb^{-1} of data on and off the \Upsilon(4S) resonance collected with the Belle detector at KEKB. Two resonant structures are observed in the pi+ pi- psi(2S) invariant mass distribution, one at 4361\pm 9\pm 9 MeV/c2 with a width of 74\pm 15\pm 10 MeV/c2, and another at 4664\pm 11\pm 5 MeV/c2 with a width of 48\pm 15\pm 3 MeV/c2, if the mass spectrum is parameterized with the coherent sum of two Breit-Wigner functions. These values do not match those of any of the known charmonium states.Comment: 10 pages, 5 figures, 2 tables, version to appear in Phys. Rev. Let

    Observation of a new D_sJ meson in B+->D0BD0K+ decays

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    We report the observation of a new DsJD_{sJ} meson produced in B+Dˉ0DsJDˉ0D0K+B^{+} \to \bar{D}^{0} D_{sJ} \to \bar{D}^{0} D^{0} K^{+}. This state has a mass of M=2708±910+11MeV/c2M=2708 \pm 9 ^{+11}_{-10} \rm{MeV}/{\it c}^{2}, a width Γ=108±2331+36 MeV/c2\Gamma = 108 \pm 23 ^{+36}_{-31} ~\rm{MeV}/ {\it c}^{2} and a 11^{-} spin-parity. The results are based on an analysis of 449 million BBˉB\bar{B} events collected at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ee^{+} e^{-} collider.Comment: submitted to Phys. Rev. Let

    Study of time-dependent CP violation in B0 -> J/Psi pi0 decays

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    We report a measurement of CP asymmetry parameters in the decay B0(B0bar) -> J/Psi pi0, which is governed by the b->c cbar d transition. The analysis is based on a 140/fb data sample accumulated at the Upsilon(4S) resonance by the belle detector at the KEKB asymmetric-energy e+e- collider. We fully reconstruct one neutral B meson in the J/Psi pi0 final state. The accompanying B meson flavor is identified by its decay products. From the distribution of proper time intervals between the two B decays, we obtain the following CP-violating parameters: S_{J/Psi pi0}=-0.72+-0.42+-0.09 and A_{J/Psi pi0}=-0.01 +-0.29+-0.03.Comment: 5 pages, 2 figures, submitted to PR

    Improved Constraints on D0-D0bar Mixing in D0 -> K+ pi- Decays from the Belle Detector

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    We report the results of a search for D0-D0bar mixing in D0 -> K+ pi- decays based on 400 fb^{-1} of data accumulated by the Belle detector at KEKB. Both assuming CP conservation and allowing for CP violation, we fit the decay-time distribution for the mixing parameters x' and y', as well as for the parameter R_D, the ratio of doubly-Cabibbo-suppressed decays to Cabibbo-favored decays. The 95% confidence level region in the (x'^2,y') plane is obtained using a frequentist method. Assuming CP conservation, we find x'^2<0.72 x 10^{-3} and -9.9 x 10^{-3}<y'<6.8 x 10^{-3} at the 95% confidence level; these are the most stringent constraints on the mixing parameters to date. The no-mixing point (0,0) has a confidence level of 3.9%. Assuming no mixing, we measure R_D=(0.377+-0.008+-0.005)%.Comment: 6 pages, 3 figures, 1 table; replaced with the version of Phys. Rev. Let

    Evidence for Direct CP Violation in B0 -> K+- pi-+ Decays

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    We report evidence for direct CP violation in the decay B0 -> K+-pi-+ with 253/fb of data collected with the Belle detector at the KEKB e+e- collider. Using 275 million B B_bar pairs we observe a B -> K+-pi-+ signal with 2140+-53 events. The measured CP violating asymmetry is Acp(K+-pi-+) = -0.101+-0.025 (stat)+-0.005 (syst), corresponding to a significance of 3.9 sigma including systematics. We also search for CP violation in the decays B+- -> K+-pi0 and B+- -> pi+-pi0. The measured CP violating asymmetries are Acp(K+-pi0) = 0.04+-0.05(stat)+-0.02(syst) and Acp(pi+-pi0) = -0.02+-0.10(stat)+-0.01(syst), corresponding to the intervals -0.05 < Acp(K+-pi0) < 0.13 and -0.18<Acp(pi+-pi0)<0.14 at 90% confidence level.Comment: 9 pages, 3 figures. submitted to Physical Review Letter

    Older Adults and Information and Communication Technologies in the Global North

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    At all ages, people are incorporating information and communication technologies (ICTs) into their lives. It is not that they have stopped talking with each other in-person, it is that ICTs complement their interactions when they cannot be together face-to-face. Since the 1990s, email has provided a routine way to stay in touch and sustain meaningful contact over distance. But not all age groups have adopted ICTs with the same enthusiasm. Research in the Global North has consistently reported that age plays an important role in ICT adoption and use (Anderson and Perrin 2017). For example, older adults have been the least likely to use ICTs, and even when they do use ICTs, they are less active in their use (Blank and Groselji 2014; Haight, Quan-Haase, and Corbett 2014; Schreurs, Quan-Haase, and Martin 2017). Yet, this is changing. As more older adults use ICTs, analysts are wondering how such ICTs affect older adults’ social networks (Wang, Zhang and Wellman 2018; Wellman, Quan-Haase and Harper forthcoming): Are ICTs helping older adults build, maintain, or diminish personal networks? And how are they supporting or limiting the exchange of social support both for local and long-distance social networks? Moreover, are ICTs affecting different types of social ties differently—be they kin, friend, neighbor, workmate, or churchgoer; or strong or weak

    QTL Analysis of Shading Sensitive Related Traits in Maize under Two Shading Treatments

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    During maize development and reproduction, shading stress is an important abiotic factor influencing grain yield. To elucidate the genetic basis of shading stress in maize, an F2:3 population derived from two inbred lines, Zhong72 and 502, was used to evaluate the performance of six traits under shading treatment and full-light treatment at two locations. The results showed that shading treatment significantly decreased plant height and ear height, reduced stem diameter, delayed day-to-tassel (DTT) and day-to-silk (DTS), and increased anthesis-silking interval (ASI). Forty-three different QTLs were identified for the six measured traits under shading and full light treatment at two locations, including seven QTL for plant height, nine QTL for ear height, six QTL for stem diameter, seven QTL for day-to-tassel, six QTL for day-to-silk, and eight QTL for ASI. Interestingly, three QTLs, qPH4, qEH4a, and qDTT1b were detected under full sunlight and shading treatment at two locations simultaneously, these QTL could be used for selecting elite hybrids with high tolerance to shading and high plant density. And the two QTL, qPH10 and qDTS1a, were only detected under shading treatment at two locations, should be quit for selecting insensitive inbred line in maize breeding procedure by using MAS method
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