2,786 research outputs found

    The Conduits and Barriers to Reentry for Formerly Incarcerated Individuals in San Bernardino

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    Numerous scholars have noted that the majority of prisoners will be reincarcerated within three years of their release. However, while there has been extensive research on recidivism, much less attention has been paid to the reentry process in the sociological and criminological literature. Given the high rates of former prisoners reentering society with struggles that may affect their friends, family members, and communities, policymakers and practitioners should understand the successful methods for their reintegration. In this paper, we explore the conduits and barriers to reentry for a sample of San Bernardino county callers using United Way’s 211 Reentry Call Center from 2014-2015. We find that human needs resources (i.e. housing, clothes, and food assistance) and legal assistance are the two most frequently requested services. The callers in our sample have intersecting, disadvantaged identities and require multiple services which suggests a need for collaboration across agencies

    Z-Z' Mixing and Z-Mediated FCNCs in SU(3)_C x SU(3)_L x U(1)_X Models

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    Most of the existing analyses of FCNC processes in the 331 models, based on the gauge group SU(3)_C x SU(3)_L x U(1)_X, take only into account tree-level exchanges of a new heavy neutral gauge boson Z'. However due to the Z-Z' mixing also corresponding contributions from Z boson are present that are usually neglected. We calculate the impact of these contributions on Delta F=2 processes and rare K, B_s and B_d decays for different values of a parameter beta, which distinguishes between various 331 models and for different fermion representations under the SU(3)_L group. We find a general expression for the Z-Z' mixing in terms beta, M_Z, M_Z' and tan(bar{beta}), familiar from 2 Higgs Doublet models, that differs from the one quoted in the literature. We study in particular the models with beta=+-n/sqrt{3} with n=1,2 which have recently been investigated by us in the context of new data on B_{s,d}->mu^+ mu^- and B_d->K^*(K)mu^+ mu^-. We find that these new contributions can indeed be neglected in the case of Delta F=2 transitions and decays, like B_d->K^*mu^+mu^-, where they are suppressed by the small vectorial Z coupling to charged leptons. However the contributions of tree-level Z exchanges to decays sensitive to axial-vector couplings, like B_{s,d}->mu^+ mu^- and B_d->K mu^+ mu^-, and those with neutrinos in the final state, like b->s nu bar{nu} transitions, K^+->pi^+ nu bar{nu} and K_L->pi^0 nu bar{nu} cannot be generally neglected with size of Z contributions depending on beta, tan(bar{beta}) and M_Z'. We analyze for the first time the ratio epsilon'/epsilon in these models including both Z' and Z contributions. Our analysis of electroweak precision observables within 331 models demonstrates transparently that the interplay of NP effects in electroweak precision observables and those in flavour observables could allow in the future to identify the favourite 331 model.Comment: 44 pages, 15 figures, 9 tables; clarifying comments added; version accepted for publication in JHE

    K+π+ννˉK^+\to\pi^+\nu\bar\nu and KLπ0ννˉK_L\to\pi^0\nu\bar\nu in the Standard Model: Status and Perspectives

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    In view of the recent start of the NA62 experiment at CERN that is expected to measure the K+π+ννˉK^+\to\pi^+\nu\bar\nu branching ratio with a precision of 10%, we summarise the present status of this promising decay within the Standard Model (SM). We do likewise for the closely related KLπ0ννˉK_L\to\pi^0\nu\bar\nu, which will be measured by the KOTO experiment around 2020. As the perturbative QCD and electroweak corrections in both decays are under full control, the dominant uncertainties within the SM presently originate from the CKM parameters VcbV_{cb}, VubV_{ub} and γ\gamma. We show this dependence with the help of analytic expressions as well as accurate interpolating formulae. Unfortunately a clarification of the discrepancies between inclusive and exclusive determinations of VcbV_{cb} and VubV_{ub} from tree-level decays will likely require results from the Belle II experiment available at the end of this decade. Thus we investigate whether higher precision on both branching ratios is achievable by determining VcbV_{cb}, VubV_{ub} and γ\gamma by means of other observables that are already precisely measured. In this context εK\varepsilon_K and ΔMs,d\Delta M_{s,d}, together with the expected progress in QCD lattice calculations will play a prominent role. We find B(K+π+ννˉ)=(9.11±0.72)×1011\mathcal{B}(K^+\to\pi^+\nu\bar\nu) = (9.11\pm 0.72) \times 10^{-11} and B(KLπ0ννˉ)=(3.00±0.30)×1011\mathcal{B}(K_L\to\pi^0\nu\bar\nu) = (3.00\pm 0.30) \times 10^{-11}, which is more precise than using averages of the present tree-level values of VcbV_{cb}, VubV_{ub} and γ\gamma. Furthermore, we point out the correlation between B(K+π+ννˉ)\mathcal{B}(K^+\to\pi^+\nu\bar\nu), B(Bsμ+μ)\overline{\mathcal{B}}(B_s\to\mu^+\mu^-) and γ\gamma within the SM, that is only very weakly dependent on other CKM parameters. Finally, we also update the ratio ε/ε\varepsilon'/\varepsilon in the SM and present its correlation with KLπ0ννˉK_L\to\pi^0\nu\bar\nu.Comment: 33 pages, 8 figures, 5 tables; v2: new correlation presented and discussion extended in section 3.2, analysis in section 5 updated, typos corrected; matches version published in JHE

    Can we reach the Zeptouniverse with rare K and B_{s,d} decays?

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    The Large Hadron Collider will directly probe distance scales as short as 10^{-19}m, corresponding to energy scales at the level of a few TeV. In order to reach even higher resolutions before the advent of future high-energy colliders, it is necessary to consider indirect probes of New Physics (NP), a prime example being Delta F=2 neutral meson mixing processes, which are sensitive to much shorter distance scales. However Delta F=2 processes alone cannot tell us much about the structure of NP beyond the LHC scales. To identify for instance the presence of new quark flavour-changing dynamics of a left-handed (LH) or right-handed (RH) nature, complementary results from Delta F=1 rare decay processes are vital. We therefore address the important question of whether NP could be seen up to energy scales as high as 200 TeV, corresponding to distances as small as 10^{-21}m -- the Zeptouniverse -- in rare K and B_{s,d} decays, subject to present Delta F=2 constraints and perturbativity. We focus in particular on a heavy Z' gauge boson. If restricted to purely LH or RH Z' couplings to quarks, we find that rare K decays, in particular KL-> pi^0 nu nubar and K^+->pi^+ nu nubar, allow us to probe the Zeptouniverse. On the other hand rare B_s and B_d decays, which receive stronger Delta F=2 constraints, allow us to reach about 15 TeV. Allowing for both LH and RH couplings a loosening of the Delta F=2 constraints is possible, and we find that the maximal values of M_Z' at which NP effects that are consistent with perturbative couplings could be found are approximately 2000 TeV for K decays and 160 TeV for rare B_{s,d} decays. Finally we present a simple idea for an indirect determination of M_Z' that could be realised at the next linear e^+e^- or mu^+ mu^- collider and with future precise flavour data.Comment: 43 pages, 10 figures, 6 tables; new section on the role of heavy neutral scalars in reaching Zeptouniverse added; clarifying comments and references adde

    Board structures around the world: An experimental investigation

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    We model and experimentally examine the board structure-performance relationship. We examine single-tiered boards, two-tiered boards, insider-controlled boards, and outsider-controlled boards. We find that even insider-controlled boards frequently adopt institutionally preferred rather than self-interested policies. Two-tiered boards adopt institutionally preferred policies more frequently, but tend to destroy value by being too conservative, frequently rejecting good projects. Outsidercontrolled single-tiered boards, both when they have multiple insiders and only a single insider, adopt institutionally preferred policies most frequently. In those board designs where the efficient Nash equilibrium produces strictly higher payoffs to all agents than the coalition-proof equilibria, agents tend to select the efficient Nash equilibria.

    Corporate board composition, protocols, and voting behavior: experimental evidence

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    We model experimentally the governance of an institution. The optimal management of this institution depends on the information possessed by insiders. However, insiders, whose interests are not aligned with the interests of the institution, may choose to use their information to further personal rather than institutional ends. Researchers (e.g., Palfrey 1990) and the business press have both argued that multiagent mechanisms, which inject trustworthy but uninformed “watchdog” agents into the governance process and impose penalties for conflicting recommendations, can implement institutionally preferred outcomes. Our laboratory experiments strongly support this conclusion. In the experimental treatments in which watchdog agents were included, the intuitionally preferred allocation was implemented in the vast majority of cases. Surprisingly, implementation occurred even in the absence of penalties for conflicting recommendations.Corporations - Finance ; Game theory

    Fermi-Edge Superfluorescence from a Quantum-Degenerate Electron-Hole Gas

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    We report on the observation of spontaneous bursts of coherent radiation from a quantum-degenerate gas of nonequilibrium electron-hole pairs in semiconductor quantum wells. Unlike typical spontaneous emission from semiconductors, which occurs at the band edge, the observed emission occurs at the quasi-Fermi edge of the carrier distribution. As the carriers are consumed by recombination, the quasi-Fermi energy goes down toward the band edge, and we observe a continuously red-shifting streak. We interpret this emission as cooperative spontaneous recombination of electron-hole pairs, or superfluorescence, which is enhanced by Coulomb interactions near the Fermi edge. This novel many-body enhancement allows the magnitude of the spontaneously developed macroscopic polarization to exceed the maximum value for ordinary superfluorescence, making electron-hole superfluorescence even more "super" than atomic superfluorescence.Comment: 10 pages, 5 figure

    High-temperature superconducting fault current microlimiters

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    High-temperature superconducting microbridges implemented with YBa(2)Cu(3)O(7-delta) thin-films are shown to be possible fault current limiters for microelectronic devices with some elements working at temperatures below the superconducting critical temperature and, simultaneously, under very low power conditions (below 1W). This is the case in the important applications of superconductors as SQUID based electronics, and technologies for communication or infrared detectors. In this paper it is shown that the good thermal behavior of these microlimiters allows working in a regime where even relatively small faults induce their transition to highly dissipative states, dramatically increasing their limitation efficiency. The conditions for optimal refrigeration and operation of these microlimiters are also proposed.Comment: 10 pages, 3 figures. LaTeX and EPS file

    Corporate Disclosure Practices, Institutional Investors, and Stock Return Volatility

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    This paper investigates whether the quality of a firm’s disclosure practices affects the composition of a firm’s institutional investor base and whether this association has implications for a firm’s stock return volatility. The findings indicate that firms with higher disclosure quality, as measured by AIMR rankings, have greater institutional ownership, but the particular types of institutional investors that are attracted to disclosure quality tend to have no net impact on firms’ stock return volatility. In contrast, improvements in disclosure quality are shown to produce contemporaneous increases in ownership primarily by transient-type institutions. Such institutions can be characterized as having a short-term investment focus along with a propensity to trade aggressively. The findings indicate that firms with disclosure quality improvements resulting in higher transient institutional investor ownership experience subsequent increases in stock return volatility
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