15,412 research outputs found

    Evaluating the employment impact of a mandatory job search program

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    This paper exploits area-based piloting and age-related eligibility rules to identify treatment effects of a labor market program—the New Deal for Young People in the U.K. A central focus is on substitution/displacement effects and on equilibrium wage effects. The program includes extensive job assistance and wage subsidies to employers. We find that the impact of the program significantly raised transitions to employment by about 5 percentage points. The impact is robust to a wide variety of nonexperimental estimators. However, we present some evidence that this effect may not be as large in the longer run

    Scaling limit for a drainage network model

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    We consider the two dimensional version of a drainage network model introduced by Gangopadhyay, Roy and Sarkar, and show that the appropriately rescaled family of its paths converges in distribution to the Brownian web. We do so by verifying the convergence criteria proposed by Fontes, Isopi, Newman and Ravishankar.Comment: 15 page

    Axion Like Particles and the Inverse Seesaw Mechanism

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    Light pseudoscalars known as axion like particles (ALPs) may be behind physical phenomena like the Universe transparency to ultra-energetic photons, the soft Îł\gamma-ray excess from the Coma cluster, and the 3.5 keV line. We explore the connection of these particles with the inverse seesaw (ISS) mechanism for neutrino mass generation. We propose a very restrictive setting where the scalar field hosting the ALP is also responsible for generating the ISS mass scales through its vacuum expectation value on gravity induced nonrenormalizable operators. A discrete gauge symmetry protects the theory from the appearance of overly strong gravitational effects and discrete anomaly cancellation imposes strong constraints on the order of the group. The anomalous U(1)(1) symmetry leading to the ALP is an extended lepton number and the protective discrete symmetry can be always chosen as a subgroup of a combination of the lepton number and the baryon number.Comment: 29pp. v4: published version with erratum. Conclusions unchange

    Evaluating the employment effects of a mandatory job search program

    Get PDF
    This paper exploits area based piloting and age-related eligibility rules to identify treatment effects of a labor market program – the New Deal for Young People in the UK. A central focus is on substitution/displacement effects and on equilibrium wage effects. The program includes extensive job assistance and wage subsidies to employers. We find that the initial impact of the program significantly raised transitions to unsubsidized employment by about five percentage points. The impact is robust to a wide variety of non-experimental estimators. However we present some evidence that this effect may not be as large in the longer run

    Evading the Few TeV Perturbative Limit in 3-3-1 Models

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    Some versions of the electroweak SU(3)_L\otimesU(1)_X models cannot be treated within perturbation theory at energies of few TeV. An extended version for these models is proposed which is perturbative even at TeV scale posing no threatening inconsistency for test at future colliders. The extension presented here needs the addition of three octets of vector leptons, which leave three new leptonic isotriplets in the SU(2)_L\otimesU(1)_Y subgroup. With this representation content the running of the electroweak mixing angle, ΞW(ÎŒ)\theta_W (\mu), is such that sin⁥2ΞW(ÎŒ)\sin^2\theta_W(\mu) decreases with the increase of the energy scale ÎŒ\mu, when only the light states of the Standard Model group are considered. The neutral exotic gauge boson Zâ€ČZ^\prime marks then a new symmetry frontier.Comment: 15 pages, 2 figures, minor correction

    Bridge over troubled gas: clusters and associations under the SMC and LMC tidal stresses

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    We obtained SOAR telescope B and V photometry of 14 star clusters and 2 associations in the Bridge tidal structure connecting the LMC and SMC. These objects are used to study the formation and evolution of star clusters and associations under tidal stresses from the Clouds. Typical star clusters in the Bridge are not richly populated and have in general relatively large diameters (~30-35 pc), being larger than Galactic counterparts of similar age. Ages and other fundamental parameters are determined with field-star decontaminated photometry. A self-consistent approach is used to derive parameters for the most-populated sample cluster NGC 796 and two young CMD templates built with the remaining Bridge clusters. We find that the clusters are not coeval in the Bridge. They range from approximately a few Myr (still related to optical HII regions and WISE and Spitzer dust emission measurements) to about 100-200 Myr. The derived distance moduli for the Bridge objects suggests that the Bridge is a structure connecting the LMC far-side in the East to the foreground of the SMC to the West. Most of the present clusters are part of the tidal dwarf candidate D 1, which is associated with an H I overdensity. We find further evidence that the studied part of the Bridge is evolving into a tidal dwarf galaxy, decoupling from the Bridge.Comment: 15 pages, 15 figures, MNRAS, Accepted 2015 July 2

    Y(4260) as a mixed charmonium-tetraquark state

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    Using the QCD sum rule approach we study the Y(4260) state assuming that it can be described by a mixed charmonium-tetraquark current with JPC=1−−J^{PC}=1^{--} quantum numbers. For the mixing angle around ξ≈(53.0±0.5)0\theta \approx (53.0\pm 0.5)^{0}, we obtain a value for the mass which is in good agreement with the experimental mass of the Y(4260). However, for the decay width we find the value \Ga_Y \approx (1.0\pm 0.2) MeV which is not compatible with the experimental value \Ga \approx (88\pm 23) MeV. Therefore, we conclude that, although we can explain the mass of the Y(4260), this state cannot be described as a mixed charmonium-tetraquark state since, with this assumption, we can not explain its decay width.Comment: 9 pages, 6 figure
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