3,647 research outputs found
Higgs boson search significance deformations due to mixed-in scalars
The existence of exotic scalars that mix with the Standard Model (SM) Higgs
boson can affect Higgs boson phenomenology in a multitude of ways. We consider
two light Higgs bosons with shared couplings to SM fields and with masses close
to each other, in the range where the h \to WW \to l \nu l \nu is an important
search channel. In this channel, we do not find the dilution of significance of
the `SM-like' Higgs boson that is naively expected because of the mixing. This
is because of leakage of events from the decay of the other scalar into its
signal region. Nevertheless, we show that the broadening of the h\to WW \to l
\nu l \nu significance plots of Standard Model Higgs boson searches could
indicate the first evidence of the the extra scalar state.Comment: 6 pages, 6 figures; v2: all plots now made with the lighter Higgs
mass equal to 125 GeV and other minor corrections made, to be published in
Physics Letters
Liquid-like behaviour of gold nanowire bridges
A combination of Focused Ion Beam (FIB) and Reactive Ion Etch (RIE) was used to fabricate free standing gold nanowire bridges with radii of 30 nm and below. These were subjected to point loading to failure at their mid-points using an Atomic Force Microscope (AFM), providing strength and deformation data. The results demonstrate a dimensionally dependent transition from conventional solid metallic properties to liquid-like behaviour including the unexpected reformation of a fractured bridge. The work reveals mechanical and materials properties of nanowires which could have significant impact on nanofabrication processes and nanotechnology devices such as Nano Electro Mechanical Systems (NEMS)
Patterns of local and nonlocal water resource use across the western U.S. determined via stable isotope intercomparisons
In the western U.S., the mismatch between public water demands and natural water availability necessitates large interbasin transfers of water as well as groundwater mining of fossil aquifers. Here we identify probable situations of nonlocal water use in both space and time based on isotopic comparisons between tap waters and potential water resources within hydrologic basins. Our approach, which considers evaporative enrichment of heavy isotopes during storage and distribution, is used to determine the likelihood of local origin for 612 tap water samples collected from across the western U.S. We find that 64% of samples are isotopically distinct from precipitation falling within the local hydrologic basin, a proxy for groundwater with modern recharge, and 31% of samples are isotopically distinct from estimated surface water found within the local basin. Those samples inconsistent with local water sources, which we suggest are likely derived from water imported from other basins or extracted from fossil aquifers, are primarily clustered in southern California, the San Francisco Bay area, and central Arizona. Our isotope-based estimates of nonlocal water use are correlated with both hydrogeomorphic and socioeconomic properties of basins, suggesting that these factors exert a predictable influence on the likelihood that nonlocal waters are used to supply tap water. We use these basin properties to develop a regional model of nonlocal water resource use that predicts (r2 = 0.64) isotopically inferred patterns and allows assessment of total interbasin transfer and/or fossil aquifer extraction volumes across the western U.S.Fil: Good, Stephen P.. University of Utah; Estados UnidosFil: Kennedy, Casey D.. United States Department Of Agriculture. Agriculture Research Service; Estados UnidosFil: Stalker Jeremy C.. Jacksonville University; Estados UnidosFil: Chesson, Lesley A.. IsoForensics; Estados UnidosFil: Valenzuela, Luciano Oscar. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Sociales. Departamento de Arqueología. Laboratorio de Ecología Evolutiva Humana (Sede Quequén); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. University of Utah; Estados UnidosFil: Beasley, Melanie M.. University of California at San Diego; Estados UnidosFil: Ehleringer, James R. University of Utah; Estados UnidosFil: Bowen, Gabriel J.. University of Utah; Estados Unido
An Analysis of Private School Closings
We add to the small literature on private school supply by exploring exits of K-12 private schools. We find that the closure of private schools is not an infrequent event, and use national survey data from the National Center for Education Statistics to study closures of private schools. We assume that the probability of an exit is a function of excess supply of private schools over the demand, as well as the school's characteristics such as age, size, and religious affiliation. Our empirical results generally support the implications of the model. Working Paper 07-0
STX209 (Arbaclofen) for Autism Spectrum Disorders: An 8-Week Open-Label Study
STX209 (arbaclofen), a selective GABA-B agonist, is hypothesized to modulate the balance of excitatory to inhibitory neurotransmission, and has shown preliminary evidence of benefit in fragile X syndrome. We evaluated its safety, tolerability, and efficacy in non-syndromic autism spectrum disorders, in an 8-week open-label trial enrolling 32 children and adolescents with either Autistic Disorder or Pervasive Developmental Disorder—Not Otherwise Specified, and a score ≥17 on the Aberrant Behavior Checklist (ABC)—Irritability subscale. STX209 was generally well-tolerated. The most common adverse events were agitation and irritability, which typically resolved without dose changes, and were often felt to represent spontaneous variation in underlying symptoms. Improvements were observed on several outcome measures in this exploratory trial, including the ABC-Irritability (the primary endpoint) and the Lethargy/Social Withdrawal subscales, the Social Responsiveness Scale, the CY-BOCS-PDD, and clinical global impression scales. Placebo-controlled study of STX209 is warranted.Seaside Therapeutics Inc
Dark matter and Higgs boson collider implications of fermions in an abelian-gauged hidden sector
We add fermions to an abelian-gauged hidden sector. We show that the lightest
can be the dark matter with the right thermal relic abundance, and discovery is
within reach of upcoming dark matter detectors. We also show that these
fermions change Higgs boson phenomenology at the Large Hadron Collider (LHC),
and in particular could induce a large invisible width to the lightest Higgs
boson state. Such an invisibly decaying Higgs boson can be discovered with good
significance in the vector boson fusion channel at the LHC.Comment: 14 pages, 6 figure
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