808 research outputs found
Search For Dark Photons From Neutral Meson Decays In p+p And d+ Au Collisions At √sNN =200 GeV
No full textThe standard model (SM) of particle physics is spectacularly successful, yet the measured value of the muon anomalous magnetic moment (g-2)μ deviates from SM calculations by 3.6σ. Several theoretical models attribute this to the existence of a dark photon, an additional U(1) gauge boson, which is weakly coupled to ordinary photons. The PHENIX experiment at the Relativistic Heavy Ion Collider has searched for a dark photon, U, in π0,η→γe+e- decays and obtained upper limits of O(2×10‐⁶) U-γ mixing at 90% C.L. for the mass range 30\u3c mᵤ \u3c 90 MeV/c². Combined with other experimental limits, the remaining region in the U-γ mixing parameter space that can explain the (g-2)ᵤ deviation from its SM value is nearly completely excluded at the 90% confidence level, with only a small region of 2
Gluon-Spin contribution to the proton spin from the double-helicity asymmetry in inclusive π0 production in polarized p+p collisions at square root of s = 200 GeV
No full textThe double helicity asymmetry in neutral pion production for pT ¼ 1 to 12 GeV=c was measured with the PHENIX experiment to access the gluon-spin contribution, G, to the proton spin. Measured asymmetries are consistent with zero, and at a theory scale of 2 ¼ 4 GeV2 a next to leading order QCD analysis gives G½0:02;0:3 ¼ 0:2, with a constraint of 0:7 \u3c G½0:02;0:3 \u3c 0:5 at 2 ¼ 9 (3) for the sampled gluon momentum fraction (x) range, 0.02 to 0.3. The results are obtained using predictions for the measured asymmetries generated from four representative fits to polarized deep inelastic scattering data. We also consider the dependence of the G constraint on the choice of the theoretical scale, a dominant uncertainty in these predictions
Study Of The Solar Anisotropy Of Cosmic Ray Primaries Of About 200 GeV Energy With The L3+C Muon Detector
No full textContext. Primary cosmic rays experience multiple deflections in the non-uniform galactic and heliospheric magnetic fields which may generate anisotropies. Aims. A study of anisotropies in the energy range between 100 and 500 GeV is performed. This energy range is not yet well explored. Methods. The L3 detector at the CERN electron-positron collider, LEP, is used for a study of the angular distribution of atmospheric muons with energies above 20 GeV. This distribution is used to investigate the isotropy of the time-dependent intensity of the primary cosmic-ray flux with a Fourier analysis. Results. A small deviation from isotropy at energies around 200 GeV is observed for the second harmonics at the solar frequency. No sidereal anisotropy is found at a level above 10ˉ⁴. The measurements were performed in the years 1999 and 2000
Measurement of g\u3csub\u3eA\u3c/sub\u3e and g\u3csub\u3ev\u3c/sub\u3e, the neutral current coupling constants to leptons
No full text\u3cp\u3eWe have measured both the rates and the forward-backward asymmetry of ℓ\u3csup\u3e+\u3c/sup\u3eℓ\u3csup\u3e-\u3c/sup\u3e from Z\u3csup\u3e0\u3c/sup\u3e→ℓ\u3csup\u3e+\u3c/sup\u3eℓ\u3csup\u3e-\u3c/sup\u3e (where ℓ=μ, τ) with the L3 detector. We obtained Γ\u3csub\u3eℓℓ\u3c/sub\u3e=88±4±3 MeV and the vector neutral current coupling constant, g\u3csub\u3ev\u3c/sub\u3e=0.00±0.07 and the axial vector neutral current coupling constant, g\u3csub\u3eA\u3c/sub\u3e=-0.515±0.015.\u3c/p\u3
Apples and oranges? A comparison of the public expenditure of the Visegrád countries
No full textIn this article, the average expenditure of Hungary is compared to that of the other three Visegrád countries. In Hungary, this expenditure is higher by 10 % of GDP, but one-quarter of this is attributable to higher interest expenses, and one-third to revenue factors which simultaneously increase both revenues and expenses. These revenue factors have a neutral impact in terms of the deficit, but they distort the comparison in respect of the levels of expenditure. For example, the tax content of public expenditures, the sales and fee revenues collected directly to cover the expenditures, and the size of EU subsidies – flowing through the budget – vary considerably from one country to the next. Two-thirds of the remaining 4-percentage point difference appears in relation to households’ cash transfers (pensions, family allowances). Hungary spends more on public services and economic subsidies, but less on the current and capital expenditure of healthcare institutions.government expenditure, public spending, Visegrad countries.
Production of nucleon resonances by single diffraction dissociation at the CERN ISR
No full textThe single diffraction dissociation process pp to (p pi /sup +/ pi /sup -/)p has been studied at the CERN ISR at square root s=45 GeV and 0.1<-t<0.6 GeV/sup 2/. The reaction is dominated by nucleon resonance production: pp to pN(1520) and pp to pN(1688) with cross-sections (0.25+or-0.08) mb and (0.56+or-0.19) mb respectively. (9 refs)
The Impact of the Crisis on Budget Policy in Central and Eastern Europe
No full textThis paper describes the particular impacts of the financial and economic crisis on Central and Eastern European (CEE) countries, studies pro-cyclicality of fiscal policies, discusses the impact of the crisis on fiscal policy, and the policy response of various governments. After drawing some lessons for fiscal policy from previous emerging market crises, the paper concludes with some thoughts on the appropriate policy response from a more normative perspective. The key message of the paper is that the crisis should be used as an opportunity to introduce reforms to avoid future pro-cyclical fiscal policies, to increase the quality of budgeting and to increase credibility. These reforms should include fiscal responsibility laws comprising medium-term fiscal frameworks, fiscal rules, and independent fiscal councils. When fiscal consolidation is accompanied by fiscal reforms that increase credibility, non-Keynesian effects may offset to some extent the contraction caused by the consolidation.budget policy, Central and Eastern European (CEE) countries, financial and economic crisis
Forensic‐Based and Environmentally Responsible Protocol to Manage Shark Fatal Bites on Humans Can Better Contribute to Conservation Needs
No full textInternational audienceAlthough sharks are important for marine ecosystems, they still suffer culling campaigns after human fatalities. A case study from the Caribbean shows how the rapid use of several complementary and reproducible forensic techniques not only allowed the confirmation of the species implicated in the bite but also the accurate assessment of the size of the animal. Six non‐lethal fishing sessions led to the capture of several shark individuals that were released after either being eliminated due to their unsuitable size or the absence of human remains in their stomach. Such an ecologically responsible risk management can contribute to shark conservation
High mass photon pairs in lepton+ lepton-gamma gamma events at LEP
No full textHigh mass photon pairs in lepton+ lepton-gamma gamma events at LEP Adriani, O.; Aguilar-Benitez, M.; Ahlen, S.P.; Alcaraz, J.; Aloisio, A.; Alverson, G.; Alviggi, M.G.; Ambrosi, G.; Linde, F.L. Published in: Physics Letters B DOI: 10.1016/0370-2693(92)91576-U Link to publication Citation for published version (APA): Adriani, O., Aguilar-Benitez, M., Ahlen, S. P., Alcaraz, J., Aloisio, A., Alverson, G., ... Linde, F. L. (1992). High mass photon pairs in lepton+ lepton-gamma gamma events at LEP. Physics Letters B, 295,[337][338][339][340][341][342][343][344][345][346] https://doi.org/10.1016/0370-2693(92)91576-U General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Download date: 28 Jun 2019 Physics Letters B 295 (1992) From the analysis of the reactions e + e-~ g + g-(n?) (g = e, #, ~) we observe four events, one e+e -~'7 and three #+ ~-??, with the invariant mass of the photon pairs close to 60 GeV. These events were selected from a data sample collected in the L3 detector corresponding to 950000 produced Z°'s. More data are necessary to ascertain the origin of these events
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