172 research outputs found

    Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay

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    The decay channel Ļˆā€²ā†’Ļ€+Ļ€āˆ’J/Ļˆ(J/Ļˆā†’Ī³ppĖ‰)\psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) is studied using a sample of 1.06Ɨ1081.06\times 10^8 Ļˆā€²\psi^\prime events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the ppĖ‰p\bar{p} invariant mass spectrum. The enhancement can be fit with an SS-wave Breit-Wigner resonance function with a resulting peak mass of M=1861āˆ’13+6(stat)āˆ’26+7(syst)MeV/c2M=1861^{+6}_{-13} {\rm (stat)}^{+7}_{-26} {\rm (syst)} {\rm MeV/}c^2 and a narrow width that is Ī“<38MeV/c2\Gamma<38 {\rm MeV/}c^2 at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics

    Graphene Photonics and Optoelectronics

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    The richness of optical and electronic properties of graphene attracts enormous interest. Graphene has high mobility and optical transparency, in addition to flexibility, robustness and environmental stability. So far, the main focus has been on fundamental physics and electronic devices. However, we believe its true potential to be in photonics and optoelectronics, where the combination of its unique optical and electronic properties can be fully exploited, even in the absence of a bandgap, and the linear dispersion of the Dirac electrons enables ultra-wide-band tunability. The rise of graphene in photonics and optoelectronics is shown by several recent results, ranging from solar cells and light emitting devices, to touch screens, photodetectors and ultrafast lasers. Here we review the state of the art in this emerging field.Comment: Review Nature Photonics, in pres

    Murine Gamma Herpesvirus 68 Hijacks MAVS and IKKĪ² to Abrogate NFĪŗB Activation and Antiviral Cytokine Production

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    Upon viral infection, mitochondrial antiviral signaling (MAVS) protein serves as a key adaptor to promote cytokine production. We report here that murine gamma herpesvirus 68 (Ī³HV68), a model virus for oncogenic human gamma herpesviruses, subverts cytokine production via the MAVS adaptor. During early infection, Ī³HV68 hijacks MAVS and IKKĪ² to induce the site-specific phosphorylation of RelA, a crucial subunit of the transcriptionally active NFĪŗB dimer, which primes RelA for the proteasome-mediated degradation. As such, Ī³HV68 efficiently abrogated NFĪŗB activation and cytokine gene expression. Conversely, uncoupling RelA degradation from Ī³HV68 infection promoted NFĪŗB activation and elevated cytokine production. Loss of MAVS increased cytokine production and immune cell infiltration in the lungs of Ī³HV68-infected mice. Moreover, exogenous expression of the phosphorylation- and degradation-resistant RelA variant restored Ī³HV68-induced cytokine production. Our findings uncover an intricate strategy whereby signaling via the upstream MAVS adaptor is intercepted by a pathogen to nullify the immediate downstream effector, RelA, of the innate immune pathway

    Branching fraction measurements of Ļ‡c0 and Ļ‡c2 to Ļ€0Ļ€0 and Ī·Ī·

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    Using a sample of 1.06Ɨ108 Ļˆ ā€² decays collected by the BESIII detector, Ļ‡c0 and Ļ‡c2 decays into Ļ€0Ļ€0 and Ī·Ī· are studied. The branching fraction results are Br(Ļ‡c0ā†’Ļ€ 0Ļ€0)=(3.23Ā±0.03Ā±0.23Ā±0.14)Ɨ10 -3, Br(Ļ‡c2ā†’Ļ€0Ļ€0)=(8.8Ā±0.2Ā±0.6Ā±0.4)Ɨ10 -4, Br(Ļ‡c0ā†’Ī·Ī·)=(3.44Ā±0.10Ā±0. 24Ā±0.2)Ɨ10 -3, and Br(Ļ‡c2ā†’Ī·Ī·)=(6. 5Ā±0.4Ā±0.5Ā±0.3)Ɨ10 -4, where the uncertainties are statistical, systematic due to this measurement, and systematic due to the branching fractions of Ļˆ ā€²ā†’ Ī³Ļ‡cJ. The results provide information on the decay mechanism of Ļ‡c states into pseudoscalars. Ā© 2010 The American Physical Society.published_or_final_versio

    Measurement of the matrix element for the decay Ī·ā€²ā†’Ī·Ļ€ +Ļ€ -

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    The Dalitz plot of Ī·āŠƒā€²ā†’Ī·Ļ€āŠƒ+Ļ€āŠƒ- decay is studied using (225.2Ā±2.8)Ɨ106 J/Ļˆ events collected with the BESIII detector at the BEPCII eāŠƒ+eāŠƒ- collider. With the largest sample of Ī·āŠƒā€² decays to date, the parameters of the Dalitz plot are determined in a generalized and a linear representation. Also, the branching fraction of J/Ļˆā†’Ī³Ī·āŠƒā€² is determined to be (4.84Ā±0.03Ā±0.24)Ɨ10āŠƒ-3, where the first error is statistical and the second systematic. Ā© 2011 American Physical Society.published_or_final_versio

    First observation of the decays Ļ‡cJā†’Ļ€0Ļ€0Ļ€0Ļ€0

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    We present a study of the P-wave spin-triplet charmonium Ļ‡ cJ decays (J=0, 1, 2) into Ļ€0Ļ€0Ļ€0Ļ€0. The analysis is based on 106Ɨ106 ĻˆāŠƒā€² decays recorded with the BESIII detector at the BEPCII electron positron collider. The decay into the Ļ€0Ļ€0Ļ€0Ļ€0 hadronic final state is observed for the first time. We measure the branching fractions B(Ļ‡ c0ā†’Ļ€0Ļ€0Ļ€0Ļ€0)=(3.34Ā±0. 06Ā±0.44)Ɨ10āŠƒ-3, B(Ļ‡ c1ā†’Ļ€0Ļ€0Ļ€0Ļ€0) =(0.57Ā±0.03Ā±0.08)Ɨ10āŠƒ-3, and B(Ļ‡ c2ā†’Ļ€0Ļ€0Ļ€0Ļ€0)=(1.21Ā±0.05Ā±0.16) Ɨ10āŠƒ-3, where the uncertainties are statistical and systematical, respectively. Ā© 2011 American Physical Society.published_or_final_versio

    Higher-order multipole amplitude measurement in Ļˆ ā€²ā†’Ī³Ļ‡ c2

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    Using 106Ɨ106 Ļˆ ā€² events collected with the BESIII detector at the BEPCII storage ring, the higher-order multipole amplitudes in the radiative transition Ļˆ ā€²ā†’Ī³Ļ‡ c2ā†’Ī³Ļ€ +Ļ€ -/Ī³K +K - are measured. A fit to the Ļ‡ c2 production and decay angular distributions yields M2=0.046Ā±0. 010Ā±0.013 and E3=0.015Ā±0.008Ā±0.018, where the first errors are statistical and the second systematic. Here M2 denotes the normalized magnetic quadrupole amplitude and E3 the normalized electric octupole amplitude. This measurement shows evidence for the existence of the M2 signal with 4.4Ļƒ statistical significance and is consistent with the charm quark having no anomalous magnetic moment. Ā© 2011 American Physical Society.published_or_final_versio

    Study of a00(980)-f0(980) mixing

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    Using samples of 2.25Ɨ108 J/Ļˆ events and 1.06Ɨ108 Ļˆ ā€² events collected with the BES III detector, we study the f 0(980)ā†’a00(980) and a00(980)ā†’f 0(980) transitions in the processes J/Ļˆā†’Ļ†f 0(980) ā†’Ļ†a00(980) and Ļ‡ c1ā†’Ļ€0a00(980)ā†’Ļ€0f 0(980), respectively. Evidence for f 0(980)ā†’a00(980) is found with a significance of 3.4Ļƒ, while in the case of a00(980)ā†’f 0(980) transition, the significance is 1.9Ļƒ. Measurements and upper limits of both branching ratios and mixing intensities are determined. Ā© 2011 American Physical Society.published_or_final_versio

    The Current State of Proteomics in GI Oncology

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    Proteomics refers to the study of the entire set of proteins in a given cell or tissue. With the extensive development of protein separation, mass spectrometry, and bioinformatics technologies, clinical proteomics has shown its potential as a powerful approach for biomarker discovery, particularly in the area of oncology. More than 130 exploratory studies have defined candidate markers in serum, gastrointestinal (GI) fluids, or cancer tissue. In this article, we introduce the commonly adopted proteomic technologies and describe results of a comprehensive review of studies that have applied these technologies to GI oncology, with a particular emphasis on developments in the last 3Ā years. We discuss reasons why the more than 130 studies to date have had little discernible clinical impact, and we outline steps that may allow proteomics to realize its promise for early detection of disease, monitoring of disease recurrence, and identification of targets for individualized therapy

    Determination of the number of J/Ļˆ events with J/Ļˆ ā†’ inclusive decays

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