{Search for direct production of GeV-scale resonances decaying to a pair of muons in proton-proton collisions at s \sqrt{s} = 13 TeV}

A search for direct production of low-mass dimuon resonances is performed using = 13 TeV proton-proton collision data collected by the CMS experiment during the 2017–2018 operation of the CERN LHC with an integrated luminosity of 96.6 fb−1. The search exploits a dedicated high-rate trigger stream that records events with two muons with transverse momenta as low as 3 GeV but does not include the full event information. The search is performed by looking for narrow peaks in the dimuon mass spectrum in the ranges of 1.1–2.6 GeV and 4.2–7.9 GeV. No significant excess of events above the expectation from the standard model background is observed. Model-independent limits on production rates of dimuon resonances within the experimental fiducial acceptance are set. Competitive or world’s best limits are set at 90% confidence level for a minimal dark photon model and for a scenario with two Higgs doublets and an extra complex scalar singlet (2HDM+S). Values of the squared kinetic mixing coefficient ε2 in the dark photon model above 10−6 are excluded over most of the mass range of the search. In the 2HDM+S, values of the mixing angle sin(θH) above 0.08 are excluded over most of the mass range of the search with a fixed ratio of the Higgs doublets vacuum expectation tan β = 0.5

Leading Sectors and Leading Regions: Economic Restructuring and Regional Inequality in Hungary since 1990

This article examines factors accounting for persisting regional inequality in Hungary during the regime change from socialism to a market economy in 1990. We examine the determinants of regional inequality through the lens of "leading sector theory" which has been used to explain why some ex-socialist countries have done better than others during the transformation. In other words, we ask whether some regions of Hungary are doing better than others for the same reasons that some ex-socialist countries have outperformed their counterparts. We use county level data from the Hungarian Central Statistical Office to examine whether the quantity and types of foreign direct investment counties have received since 1990 are associated with regional inequality in per capita GDP. We find that foreign capitalists concentrate human-capital-intensive investment in already well performing locations because they have similar supply structures to their home economies. We also contend that no measure of institutional modernization is likely to make lagging regions attractive candidates for human-capital-intensive investments in the near future. Hence, regardless of the national state's efforts to target development to lagging areas, or the effectiveness of local institutions, lagging regions are likely to remain underdeveloped. We recommend that future field-based research be conducted to examine the nexus between FDI, the nation state and localities. Unraveling interrelationships between these three political economy sites will expose the causal forces sustaining regional inequalities during post-socialism. Copyright (c) 2007 The Authors. Journal Compilation (c) 2007 Joint Editors and Blackwell Publishing Ltd.