2,790 research outputs found
The Conduits and Barriers to Reentry for Formerly Incarcerated Individuals in San Bernardino
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
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
and in the Standard Model: Status and Perspectives
In view of the recent start of the NA62 experiment at CERN that is expected
to measure the 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 ,
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 , and . 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 and 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 , and by means of
other observables that are already precisely measured. In this context
and , together with the expected progress in
QCD lattice calculations will play a prominent role. We find
and
, which is
more precise than using averages of the present tree-level values of ,
and . Furthermore, we point out the correlation between
,
and within the SM, that is
only very weakly dependent on other CKM parameters. Finally, we also update the
ratio in the SM and present its correlation with
.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?
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
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
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
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
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
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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