Neutralino Dark Matter in Mirage Mediation

We study the phenomenology of neutralino dark matter (DM) in mirage mediation scenario of supersymmetry breaking which results from the moduli stabilization in some string/brane models. Depending upon the model parameters, especially the anomaly to modulus mediation ratio determined by the moduli stabilization mechanism, the nature of the lightest supersymmetric particle (LSP) changes from Bino-like neutralino to Higgsino-like one via Bino-Higgsino mixing region. For the Bino-like LSP, the standard thermal production mechanism can give a right amount of relic DM density through the stop/stau-neutralino coannihilation or the pseudo-scalar Higgs resonance process. We also examine the prospect of direct and indirect DM detection in various parameter regions of mirage mediation. Neutralino DM in galactic halo might be detected by near future direct detection experiments in the case of Bino-Higgsino mixed LSP. The gamma ray flux from Galactic Center might be detectable also if the DM density profile takes a cuspy shape.Comment: One reference adde

b→sγb\to s\gamma Constraints on the Minimal Supergravity Model with Large tan⁡β\tan\beta

In the minimal supergravity model (mSUGRA), as the parameter $\tan\beta$ increases, the charged Higgs boson and light bottom squark masses decrease, which can potentially increase contributions from $tH^\pm$, \tg\tb_j and \tz_i\tb_j loops in the decay $b\to s\gamma$. We update a previous QCD improved $b\to s\gamma$ decay calculation to include in addition the effects of gluino and neutralino loops. We find that in the mSUGRA model, loops involving charginos also increase, and dominate over $tW$, $tH^\pm$, \tg\tq and \tz_i\tq contributions for \tan\beta\agt 5-10. We find for large values of $\tan\beta \sim 35$ that most of the parameter space of the mSUGRA model for $\mu <0$ is ruled out due to too large a value of branching ratio $B(b\to s\gamma)$. For $\mu >0$ and large $\tan\beta$, most of parameter space is allowed, although the regions with the least fine-tuning (low $m_0$ and $m_{1/2}$) are ruled out due to too low a value of $B(b\to s\gamma)$. We compare the constraints from $b\to s\gamma$ to constraints from the neutralino relic density, and to expectations for sparticle discovery at LEP2 and the Fermilab Tevatron $p\bar p$ colliders. Finally, we show that non-universal GUT scale soft breaking squark mass terms can enhance gluino loop contributions to $b\to s\gamma$ decay rate even if these are diagonal.Comment: 14 page REVTEX file plus 6 PS figure

Effects of SO(10) D-Term on Yukawa Unification and Unstable Minima of the Supersymmetric Scalar Potential

We study the effects of SO(10) D-terms on the allowed parameter space (APS) in models with $t - b - \tau$ and $b - \tau$ Yukawa unifiction. The former is allowed only for moderate values of the D-term, if very precise ($\le$ 5%) unification is required. Next we constrain the parameter space by looking for different dangerous directions where the scalar potential may be unbounded from below (UFB1 and UFB3). The common trilinear coupling $A_0$ plays a significant role in constraing the APS. For very precise $t - b - \tau$ Yukawa unification, $-m_{16} < or \approx A_0 < or \approx m_{16}$ can be probed at the LHC, where $m_{16}$ is the common soft breaking mass for the sfermions. Moreover, an interesting mass hierarchy with very heavy sfermions but light gauginos, which is strongly disfavoured in models without D-terms, becomes fairly common in the presence of the D-terms. The APS exhibits interesting characteristics if $m_{16}$ is not the same as the soft breaking mass $m_{10}$ for the Higgs sector. In $b - \tau$ unification models with D-terms, the APS consistent with Yukawa unification and radiative electroweak symmetry breaking, increases as the UFB1 constraint becomes weaker. However for $A_0 \leq 0$, a stronger UFB3 condition still puts, for a given $m_{16}$, a stringent upper bound on the common gaugino mass ($m_{1/2}$) and a lower bound on $m_{16}$ for a given $m_{1/2}$. The effects of sign of $\mu$ on Yukawa unification and UFB constraints are also discussed.Comment: Plain Latex, 22 pages, 11 figures. Small changes in the abstract, the pattern of discussion changed signifiantly, no change in the figures and results, a few new references added, version published in JP

Effective Interactions and Volume Energies in Charged Colloids: Linear Response Theory

Interparticle interactions in charge-stabilized colloidal suspensions, of arbitrary salt concentration, are described at the level of effective interactions in an equivalent one-component system. Integrating out from the partition function the degrees of freedom of all microions, and assuming linear response to the macroion charges, general expressions are obtained for both an effective electrostatic pair interaction and an associated microion volume energy. For macroions with hard-sphere cores, the effective interaction is of the DLVO screened-Coulomb form, but with a modified screening constant that incorporates excluded volume effects. The volume energy -- a natural consequence of the one-component reduction -- contributes to the total free energy and can significantly influence thermodynamic properties in the limit of low-salt concentration. As illustrations, the osmotic pressure and bulk modulus are computed and compared with recent experimental measurements for deionized suspensions. For macroions of sufficient charge and concentration, it is shown that the counterions can act to soften or destabilize colloidal crystals.Comment: 14 pages, including 3 figure

Prison sentences: last resort or the default sanction?

This paper discusses the sentencing purposes for penal penalties, judges’ perceptions of sentencing purposes and prison sentences, and the effects of penal sanctions. We examine judges’ positions towards different penalties, with a focus on imprisonment, since their views on the different penalties are related to their sentencing decision-making. Understanding these views is then critical for several practical and political purposes, including bridging the gap between academic discourse and legal practice. We accessed judges’ views on penal sanctions through a questionnaire and an interview. Our sample is compounded by the judges of the criminal courts from the three major cities in Portugal. Despite the most recent criminological empirical knowledge, judges valued imprisonment as the most adequate sentence, both for different crimes and for different judicial purposes. This result is not consistent with viewing imprisonment as a ‘last resort’ solution. Indeed, we did not find this ‘last resort’ position in our data, and it is not apparent in the judicial statistics on imprisonment rates. Our data highlight the importance of increasing judges’ training on criminological and sociological issues as well as the importance of changing the influence of their personal beliefs regarding penal sanctions into research-based positions.This study was conducted at Psychology Research Centre (UID/PSI/01662/2013), University of Minho, and supported by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Science, Technology and Higher Education through national funds and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653). The study was also supported by Grant SFRH/BPD/108602/2015 from the Portuguese Foundation for Science and Technology awarded to the first author

Anomaly-Free Gauged R-Symmetry

We review the gauging of an R-symmetry in local and global susy. We then construct the first anomaly-free models. We break the R-symmetry and susy at the Planck scale and discuss the low-energy effects. We include a solution to the mu-problem, and the prediction of observable effects at HERA. The models also nicely allow for GUT-scale baryogenesis and R-parity violation without the sphaleron interactions erasing the baryon-asymmetry.Comment: 6 pages, latex, no figures. Talk presented at SUSY-95. Work done in collaboration with A. Chamseddin

The VVV Templates Project. Towards an Automated Classification of VVV Light-Curves. I. Building a database of stellar variability in the near-infrared

Context. The Vista Variables in the V\'ia L\'actea (VVV) ESO Public Survey is a variability survey of the Milky Way bulge and an adjacent section of the disk carried out from 2010 on ESO Visible and Infrared Survey Telescope for Astronomy (VISTA). VVV will eventually deliver a deep near-IR atlas with photometry and positions in five passbands (ZYJHK_S) and a catalogue of 1-10 million variable point sources - mostly unknown - which require classifications. Aims. The main goal of the VVV Templates Project, that we introduce in this work, is to develop and test the machine-learning algorithms for the automated classification of the VVV light-curves. As VVV is the first massive, multi-epoch survey of stellar variability in the near-infrared, the template light-curves that are required for training the classification algorithms are not available. In the first paper of the series we describe the construction of this comprehensive database of infrared stellar variability. Methods. First we performed a systematic search in the literature and public data archives, second, we coordinated a worldwide observational campaign, and third we exploited the VVV variability database itself on (optically) well-known stars to gather high-quality infrared light-curves of several hundreds of variable stars. Results. We have now collected a significant (and still increasing) number of infrared template light-curves. This database will be used as a training-set for the machine-learning algorithms that will automatically classify the light-curves produced by VVV. The results of such an automated classification will be covered in forthcoming papers of the series.Comment: 12 pages, 16 figures, 3 tables, accepted for publication in A&A. Most of the data are now accessible through http://www.vvvtemplates.org

Adiabatic compression and indirect detection of supersymmetric dark matter

Recent developments in the modelling of the dark matter distribution in our Galaxy point out the necessity to consider some physical processes to satisfy observational data. In particular, models with adiabatic compression, which include the effect of the baryonic gas in the halo, increase significantly the dark matter density in the central region of the Milky Way. On the other hand, the non-universality in scalar and gaugino sectors of supergravity models can also increase significantly the neutralino annihilation cross section. We show that the combination of both effects gives rise to a gamma-ray flux arising from the Galactic Center largely reachable by future experiments like GLAST. We also analyse in this framework the EGRET excess data above 1 GeV, as well as the recent data from CANGAROO and HESS. The analysis has been carried out imposing the most recent experimental constraints, such as the lower bound on the Higgs mass, the \bsg branching ratio, and the muon $g-2$. In addition, the recently improved upper bound on $B(B_s \to \mu^+ \mu^-)$ has also been taken into account. The astrophysical (WMAP) bounds on the dark matter density have also been imposed on the theoretical computation of the relic neutralino density through thermal production.Comment: 32 pages, 11 figures, final version to appear in JCA

Tevatron-for-LHC Report: Preparations for Discoveries

This is the "TeV4LHC" report of the "Physics Landscapes" Working Group, focused on facilitating the start-up of physics explorations at the LHC by using the experience gained at the Tevatron. We present experimental and theoretical results that can be employed to probe various scenarios for physics beyond the Standard Model.Comment: 222 pp., additional contribution added, typos/layout correcte

Production and Decay of Scalar Stoponium Bound States

In this paper we discuss possible signatures for the production of scalar \stst\ (stoponium) bound states \sigst\ at hadron colliders, where \st\ is the lighter scalar top eigenstate. We first study the decay of \sigst; explicit expressions are given for all potentially important decay modes. If \st\ has unsuppressed two--body decays, they will always overwhelm the annihilation decays of \sigst. Among the latter, we find that usually either the $gg$ or $hh$ final state dominates, depending on the size of the off--diagonal entry of the stop mass matrix; $h$ is the lighter neutral scalar Higgs boson of the minimal supersymmetric model. If \msig\ happens to be close to the mass of one of the neutral scalar Higgs bosons, $Q \bar{Q}$ final states dominate ($Q=b$ or $t$). \ww\ and $ZZ$ final states are subdominant. We argue that \sigst \rightarrow \gamgam decays offer the best signal for stoponium production at hadron colliders. The tevatron should be able to close the light stop window left open by LEP searches, but its mass reach is limited to \msig \leq 90 GeV. In contrast, at the LHC one should ultimately be able to probe the region \msig \leq 700 GeV, if the $hh$ partial width is not too large. We also comment on the feasibility of searching for \sigst\ production at hadron colliders in the $ZZ, \ Z \gamma$ and \fourtau\ final states, and briefly mention \sigst\ production at \gamgam\ colliders.Comment: 31 pages plus 10 figures (available from DREES@WISCPHEN); LaTeX with equation.sty; MAD/PH/808, KEK-TH-37