Sfermion decays into singlets and singlinos in the NMSSM

We investigate how the addition of the singlet Higgs field in the NMSSM changes the sfermion branching ratios as compared to the MSSM. We concentrate in particular on the third generation, discussing decays of the heavier stop, sbottom or stau into the lighter mass eigenstate plus a scalar or pseudoscalar singlet Higgs. We also analyse stop, sbottom and stau decays into singlinos. It turns out that the branching ratios of these decays can be large, markedly influencing the sfermion phenomenology in the NMSSM. Moreover, we consider decays of first and second generation sfermions into singlinos.Comment: 10 pages, 4 figures; a few additional remarks on the model, version to be publishe

Yukawa Induced Radiative Corrections to the Lightest Higgs Boson Mass in the NMSSM

We compute the leading logarithmic radiative corrections to the lightest Higgs mass in the NMSSM involving the electroweak gauge couplings and in the NMSSM specific Yukawa couplings lambda and kappa (including all mixed combinations), which are induced by chargino, neutralino and Higgs boson loops. The effect of the NMSSM specific Yukawa couplings lambda and kappa is to increase the upper bound on the lightest Higgs mass by up to ~2 GeV, but they can also decrease the lightest Higgs mass by up to ~-20 GeV.Comment: 12 pages, 3 figs, improved (generalized) treatment of CP odd loop contributions; the possibility to get large negative contributions to the lightest Higgs mass is clarified in a third figure; typos correcte

Cosmological evolution in compactified Horava-Witten theory induced by matter on the branes

The combined Einstein equations and scalar equation of motion in the Horava-Witten scenario of the strongly coupled heterotic string compactified on a Calabi-Yau manifold are solved in the presence of additional matter densities on the branes. We take into account the universal Calabi-Yau modulus phi with potentials in the 5-d bulk and on the 3-branes, and allow for an arbitrary coupling of the additional matter to phi and an arbitrary equation of state. No ad hoc stabilization of the five dimensional radius is assumed. The matter densities are assumed to be small compared to the potential for phi on the branes; in this approximation we find solutions in the bulk which are exact in y and t. Depending on the coupling of the matter to phi and its equation of state, various solutions for the metric on the branes and in the 5-d bulk are obtained: Solutions corresponding to a ``rolling radius'', and solutions with a static 5-d radius, which reproduce the standard cosmological evolution.Comment: 20 pages (LaTeX2e), no figs. References added and comments rectifie

The Cosmological Constant

Various contributions to the cosmological constant are discussed and confronted with its recent measurement. We briefly review different scenarious -- and their difficulties -- for a solution of the cosmological constant problem.Comment: Lecture given at the XIV Workshop "Beyond the Standard Model", Bad Honnef, 11-14 March 200

Testing the higgsino-singlino sector of the NMSSM with trileptons at the LHC

We propose a simplified light higgsino-singlino scenario in the NMSSM, in which the masses of the chargino and the lightest neutralino determine the masses and couplings of all 3 lightest neutralinos. This scenario is complementary to the simplified wino-like chargino/neutralino scenario used conventionally for the interpretation of results from trilepton searches, and motivated by lower bounds on the gluino mass in the case of GUT relations between the wino and gluino masses. We present all masses and mixing angles necessary for the determination of production cross sections of the chargino and the 3 neutralinos in the form of Tables in the M_{neutralino_1} - M_{chargino_1} plane, assuming Higgs mass motivated values for tan(beta)=2 and lambda=0.6. We show that this scenario leads to considerable signal rates, and present constraints in this plane from recent searches for trileptons at the LHC.Comment: 16 pages, 1 Figure, 8 Table

Possible explanation of excess events in the search for jets, missing transverse momentum and a Z boson in pp collisions

We study to which extent SUSY extensions of the Standard Model can describe the excess of events of 3.0 standard deviations observed by ATLAS in the on-Z signal region, respecting constraints by CMS on similar signal channels as well as constraints from searches for jets and E^{miss}_T. GMSB-like scenarios are typically in conflict with these constraints, and do not reproduce well the shape of the E^{miss}_T distribution of the data. An alternative scenario with two massive neutralinos can improve fits to the total number of events as well as to the H_T and E^{miss}_T distributions. Such a scenario can be realised within the NMSSM.Comment: 14 pages, 4 figures, 1 Table, more details of constraints and fits are discussed, to appear in EPJ

The Individual Mandate: The Ultimate Conservative Idea

The individual mandate is perhaps the most contested and least popular provision of the 2010 Affordable Care Act (ACA). The mandate, which requires most Americans to obtain health insurance or pay a penalty, was put in the ACA as a means to increase the number of Americans with access to health care insurance. A poll taken by Gallup in February 2012 revealed that 72% of Americans view the individual mandate as unconstitutional (Gallup poll, 2012). This extreme opposition towards the mandate intrigued me and I was interested in learning where this negativity was stemming from and why it seemed to be such a taboo, especially in the Republican circles. As I began to research the origin of the individual mandate, I discovered that the current Republicans opposition towards the mandate is, in fact, misguided. In my paper I conducted a careful examination of the individual mandate’s history revealing that is was originally a conservative idea and encompasses many conservative values, specifically the value of individual responsibility. In fact, the individual mandate was both introduced in various health care legislation and endorsed by republican politicians throughout the 1990s and into the 2000s. This research reveals that republican opposition towards the individual mandate has evolved only recently in the light of the passing of the ACA. What was once, accepted by many democrats and republicans as a logical way to expand access is now seen as overstepping individual freedom and rights. In my paper, I present the recent critics’ arguments against the mandate and explain why they are so prominent at this time. In addition to this, I propose solutions such as, changing the language associated with the mandate and creating a political environment that allows for bipartisanship, which will turn this opposition into acceptance of and support for the mandate

Gradient flows for β\beta functions via multi-scale renormalization group equations

Renormalization schemes and cutoff schemes allow for the introduction of various distinct renormalization scales for distinct couplings. We consider the coupled renormalization group flow of several marginal couplings which depend on just as many renormalization scales. The usual $\beta$ functions describing the flow with respect to a common global scale are assumed to be given. Within this framework one can always construct a metric and a potential in the space of couplings such that the $\beta$ functions can be expressed as gradients of the potential. Moreover the potential itself can be derived explicitly from a prepotential which, in turn, determines the metric. Some examples of renormalization group flows are considered, and the metric and the potential are compared to expressions obtained elsewhere.Comment: 8 page