We present a measurement of the ratio of the decay rates Γ(KL→π+π−)/Γ(KL→π±e∓ν), denoted as ΓK2π/ΓKe3. The analysis is based on data taken during a dedicated run in 1999 by the NA48 experiment at the ...CERN SPS. Using a sample of 47 000 K2π and five million Ke3 decays, we find ΓK2π/ΓKe3=(4.835±0.022stat.±0.016syst.)×10−3. From this we derive the branching ratio of the CP violating decay KL→π+π− and the CP violation parameter |η+−|. Excluding the CP conserving direct photon emission component KL→π+π−γ, we obtain the results BR(KL→π+π−)=(1.941±0.019)×10−3 and |η+−|=(2.223±0.012)×10−3.
The direct CP violation parameter Re(ϵ′/ϵ) has been measured from the decay rates of neutral kaons into two pions using the NA48 detector at the CERN SPS. The 2001 running period was devoted to ...collecting additional data under varied conditions compared to earlier years (1997–1999). The new data yield the result: Re(ϵ′/ϵ)=(13.7±3.1)×10−4. Combining this result with that published from the 1997, 98 and 99 data, an overall value of Re(ϵ′/ϵ)=(14.7±2.2)×10−4 is obtained from the NA48 experiment.
Segmental copy-number variations (CNVs) in the human genome are associated with developmental disorders and susceptibility to diseases. More importantly, CNVs may represent a major genetic component ...of our phenotypic diversity. In this study, using a whole-genome array comparative genomic hybridization assay, we identified 3,654 autosomal segmental CNVs, 800 of which appeared at a frequency of at least 3%. Of these frequent CNVs, 77% are novel. In the 95 individuals analyzed, the two most diverse genomes differed by at least 9 Mb in size or varied by at least 266 loci in content. Approximately 68% of the 800 polymorphic regions overlap with genes, which may reflect human diversity in senses (smell, hearing, taste, and sight), rhesus phenotype, metabolism, and disease susceptibility. Intriguingly, 14 polymorphic regions harbor 21 of the known human microRNAs, raising the possibility of the contribution of microRNAs to phenotypic diversity in humans. This in-depth survey of CNVs across the human genome provides a valuable baseline for studies involving human genetics.
The direct CP violation parameter Re(epsilon'/epsilon) has been measured from the decay rates of neutral kaons into two pions using the NA48 detector at the CERN SPS. With 3.3 million KL->pi0pi0 ...events collected during the 1998 and 1999 running periods, a result of Re(epsilon'/epsilon) = (15.0 +- 2.7)x10-4 has been obtained. The result combined with the published 1997 sample is Re(epsilon'/epsilon) = (15.3 +- 2.6)x10-4.
Monolayer graphene exhibits many spectacular electronic properties, with superconductivity being arguably the most notable exception. It was theoretically proposed that superconductivity might be ...induced by enhancing the electron–phonon coupling through the decoration of graphene with an alkali adatom superlattice Profeta G, Calandra M, Mauri F (2012)Nat Phys8(2):131–134. Although experiments have shown an adatom-induced enhancement of the electron–phonon coupling, superconductivity has never been observed. Using angle-resolved photoemission spectroscopy (ARPES), we show that lithium deposited on graphene at low temperature strongly modifies the phonon density of states, leading to an enhancement of the electron–phonon coupling of up toλ≃ 0.58. On part of the graphene-derivedπ*-band Fermi surface, we then observe the opening of a Δ ≃ 0.9-meV temperature-dependent pairing gap. This result suggests for the first time, to our knowledge, that Li-decorated monolayer graphene is indeed superconducting, withTc
≃ 5.9 K.
Data from the Sudbury Neutrino Observatory have been used to constrain the lifetime for nucleon decay to "invisible" modes, such as n-->3nu. The analysis was based on a search for gamma rays from the ...deexcitation of the residual nucleus that would result from the disappearance of either a proton or neutron from 16O. A limit of tau(inv)>2 x 10(29) yr is obtained at 90% confidence for either neutron- or proton-decay modes. This is about an order of magnitude more stringent than previous constraints on invisible proton-decay modes and 400 times more stringent than similar neutron modes.
Abstract Objective Grit, defined as “working strenuously toward challenges, maintaining effort and interest over years despite failure, adversity, and plateaus in progress,” is strongly associated ...with academic achievement and life success and may also be associated with health outcomes and behaviors. We examined predictors of grit, and the association between grit and health behaviors among at-risk Latino adolescents. Methods We analyzed baseline survey data collected in 2013–2014 from a sample of 1270 9th graders in low-income neighborhoods of Los Angeles. We examined factors associated with grit and whether grit is associated with substance use and delinquent behaviors, controlling for adolescent and parent sociodemographic factors. Results In a sample of mostly Latino adolescents (89.5%), compared to those with low grit, those with high grit had significantly lower odds of alcohol use in the last 30 days (odds ratio 0.30, P < .001), marijuana use (odds ratio 0.21, P < .05), and fighting (odds ratio 0.58, P < .05). Involvement in delinquent behavior was also lower (β = −0.71, P < .001). Factors associated with more grit included authoritative parenting style, parental employment, and high self-efficacy scores. Conclusions Grit may be an important candidate protective factor against substance use and other risk behaviors among Latino adolescents.
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