Contributions to b→sℓℓ{b \rightarrow s \ell \ell} Anomalies from R{R}-Parity Violating Interactions

We examine the parameter space of supersymmetric models with $R$-parity violating interactions of the form $\lambda' L Q D^c$ to explain the various anomalies observed in $b \rightarrow s \ell \ell$ transitions. To generate the appropriate operator in the low energy theory, we are led to a region of parameter space where loop contributions dominate. In particular, we concentrate on parameters for which diagrams involving winos, which have not been previously considered, give large contributions. Many different potentially constraining processes are analyzed, including $\tau \rightarrow \mu \mu \mu$, $B_s-\bar{B}_s$ mixing, $B \rightarrow K^{(*)} \nu \bar{\nu}$, $Z$ decays to charged leptons, and direct LHC searches. We find that it is possible to explain the anomalies, but it requires large values of $\lambda'$, which lead to relatively low Landau poles.Comment: 30 pages, 7 figures, references added, matched to journal versio

Electroweak precision measurements in supersymmetric models with a U(1)R lepton number

As experimental constraints on the parameter space of the MSSM and close variations thereof become stronger, the motivation to explore supersymmetric models that challenge some of the standard assumptions of the MSSM also become stronger. For example, models where the gauginos are Dirac instead of Majorana have recently received more attention. Beside allowing for a supersoft SUSY breaking mechanism where the gauginos only provide finite threshold corrections to scalar masses, the cross section for the production of a squark pairs is reduced. In addition, Dirac gauginos can be used to build models that possess a U(1)R symmetry. This symmetry can then be identified with a lepton number, leading to models that are quite different from conventional scenarios. The sneutrinos in these models can acquire a vev and give mass to the leptons and the down-type squark. The phenomenology is novel, combining signatures that are typical of R-parity violating scenarios with signatures arising from leptoquarks. Correspondingly the constraints from electroweak precision data are also different. In these models, one of the leptons mixes with gauginos and superpotential Yukawa couplings can contribute to EWPM at tree level. In addition, lepton universality is broken. In this paper we adapt the operators analysis of Han and Skiba [1] to include the relevant violation of lepton universality, and do a global fit of the model to electroweak precision data, including all relevant tree-level and loop-level effects. We obtain bounds on the vev of the sneutrino and on the superpotential couplings of the model.Comment: 18 pages, 6 figures, references adde

Nonisotropic 3-level Quantum Systems: Complete Solutions for Minimum Time and Minimum Energy

We apply techniques of subriemannian geometry on Lie groups and of optimal synthesis on 2-D manifolds to the population transfer problem in a three-level quantum system driven by two laser pulses, of arbitrary shape and frequency. In the rotating wave approximation, we consider a nonisotropic model i.e. a model in which the two coupling constants of the lasers are different. The aim is to induce transitions from the first to the third level, minimizing 1) the time of the transition (with bounded laser amplitudes), 2) the energy of lasers (with fixed final time). After reducing the problem to real variables, for the purpose 1) we develop a theory of time optimal syntheses for distributional problem on 2-D-manifolds, while for the purpose 2) we use techniques of subriemannian geometry on 3-D Lie groups. The complete optimal syntheses are computed.Comment: 29 pages, 6 figure

LHC constraints on Mini-Split anomaly and gauge mediation and prospects for LHC 14 and a future 100 TeV pp collider

Stringent experimental constraints have raised the lower limit on the masses of squarks to TeV levels, while compatibility with the mass of the Higgs boson provides an upper limit. This two-sided bound has lead to the emergence of Mini-Split theories where gauginos are not far removed from the electroweak scale while scalars are somewhat heavier. This small hierarchy modifies the spectrum of standard anomaly and gauge mediation, leading to Mini-Split deflected anomaly and gauge mediation models. In this paper, we study LHC constraints on these models and their prospects at LHC 14 and a 100 TeV collider. Current constraints on their parameter space come from ATLAS and CMS supersymmetry searches, the known mass of the Higgs boson, and the absence of a color-breaking vacuum. Prospects at LHC 14 and a 100 TeV collider are obtained from these same theoretical constraints in conjunction with background estimates. As would be expected from renormalization group effects, a slightly lighter third generation of squarks is assumed. Higgsinos have masses similar to those of the scalars and are at the origin of the deflection.Comment: 25 pages, 10 figures, references added, LHC 14 results added, matched to journal versio

Mirror World at the Large Hadron Collider

A mirror world can modify in a striking way the LHC signals of the Higgs sector. An exact or approximate Z_2 symmetry between the mirror world and our world allows large mixing between the Higgs bosons of these worlds, leading to production rates and branching ratios for these states that are markedly different from the standard model and are characteristic of a mirror world. The constraints on these Higgs boson masses from precision electroweak data differ from the standard model bound, so that the new physics that cancels the quadratic divergence induced by the top quark may appear at a larger scale, possibly beyond the reach of the LHC. However, the scale of new physics needed to cancel the quadratic divergence induced by the Higgs boson is not significantly changed. With small breakings of the Z_2 parity, the lightest mirror quarks (and possibly charged mirror leptons) could be the dark matter in the universe, forming galactic halos that are stable to cooling. A possible signal from the relic radiation density of the mirror world is also discussed.Comment: 15 pages, 1 figur

Development, Capitalists and Extractive Rent: Class Struggles in Venezuela and Ecuador

Through a relational class perspective, this dissertation compares the evolution of the development models in Venezuela and Ecuador since the 1970s to better understand the significance of the recent turn to the left. Based on field research in both countries comprising extensive interviews with representatives of social movements and business interest groups, it studies the main class organizations, their struggles, and their relation with the state in order to shed light on the dynamics of change in the development models pursued in each country, and the role that extractive rent plays within them. While governments associated with the pink tide in Venezuela and Ecuador were not elected under similar economic contexts, they faced comparable political conditions. In particular, both countries faced situations where class struggle adopted a particular form as popular classes lost their coordination, and the capitalist classes had significant influence over the state. In response to the challenge these conditions represented, left governments attempted to increase the capacity of the state to act with more autonomy through the adoption of new constitutions and the reassertion of state ownership over extractive resources to pursue a rent-based social-developmental model. This involved the use of extractive rent for redistributive measures and as a leverage to foster economic diversification. A comparative perspective on social classes shows how a united capitalist class in Venezuela, adopting a confrontational stance, pushed the state to rely increasingly on its role as a dispenser of rent. By contrast, a regionally divided capitalist class in Ecuador reacted less combatively, and led the Ecuadorian state to follow a social-developmental model more supportive of private initiative for economic diversification. In both cases, however, the governments put in place strategies aimed at gaining control over the responses of the popular sector. As opposed to discussions of populism, focusing on the irrational relationship between the leader and its followers, or approaches that focus on categorizing different kinds of left governments, or even perspectives that stress the determining role of natural resources, this dissertation analyzes class struggles as a crucial factor to understanding the transformation of the state and of the development model it pursues