Standard Model stability bounds for new physics within LHC reach

We analyse the stability lower bounds on the Standard Model Higgs mass by carefully controlling the scale independence of the effective potential. We include resummed leading and next-to-leading-log corrections, and physical pole masses for the Higgs boson, M_H, and the top-quark, M_t. Particular attention is devoted to the cases where the scale of new physics \Lambda is within LHC reach, i.e. \Lambda\leq 10 TeV, which have been the object of recent controversial results. We clarify the origin of discrepancies and confirm our earlier results within the error of our previous estimate. In particular for \Lambda=1 TeV we find that M_H[GeV]>52+0.64(M_t[GeV]-175)-0.50\frac{\alpha_s(M_Z)-0.118}{0.006}. For fixed values of M_t and \alpha_s(M_Z), the error from higher effects, as the lack of exact scale invariance of the effective potential and higher-order radiative corrections, is conservatively estimated to be \simlt 5 GeV.Comment: 17 pages, latex + psfig.sty, 4 figure

Grader Bias in Cattle Markets? Evidence from Iowa

Live cattle are increasingly priced as an explicit function of U.S. Department of Agriculture yield and quality grades. Human graders visually inspect each slaughtered carcass and call grades in a matter of seconds as the carcass passes on a moving trolley. We examine whether there is systematic bias in grade calls using a sample of loads delivered to three different midwestern packing plants during 2000–2002. Overall, results indicate that indeed there is a bias, and that grading standards vary significantly across packing plants. Results also are consistent with a behavioral model where graders are more accurate when grading relatively low-quality carcasses

The Minimally Tuned Minimal Supersymmetric Standard Model

The regions in the Minimal Supersymmetric Standard Model with the minimal amount of fine-tuning of electroweak symmetry breaking are presented for general messenger scale. No a priori relations among the soft supersymmetry breaking parameters are assumed and fine-tuning is minimized with respect to all the important parameters which affect electroweak symmetry breaking. The superpartner spectra in the minimally tuned region of parameter space are quite distinctive with large stop mixing at the low scale and negative squark soft masses at the high scale. The minimal amount of tuning increases enormously for a Higgs mass beyond roughly 120 GeV.Comment: 38 pages, including 2 appendices, 8 figure

Reduced graphene oxides as carbocatalysts in acceptorless dehydrogenation of N-heterocycles

The catalytic properties of graphene-derived materials are evaluated in acceptorless dehydrogenation of N-heterocycles. Among them, reduced graphene oxides (rGOs) are active (quantitative yields in 23 h) under mild conditions (130 °C) and act as efficient heterogeneous carbocatalysts. rGO exhibits reusability and stability at least during eight consecutive runs. Mechanistic investigations supported by experimental evidence (i.e., organic molecules as model compounds, purposely addition of metal impurities and selective functional group masking experiments) suggest a preferential contribution of ketone carbonyl groups as active sites for this transformation.

The Standard Model instability and the scale of new physics

We apply a general formalism for the improved effective potential with several mass scales to compute the scale M of new physics which is needed to stabilize the Standard Model potential in the presence of a light Higgs. We find, by imposing perturbativity of the new physics, that M can be as large as one order of magnitude higher than the instability scale of the Standard Model. This implies that, with the present lower bounds on the Higgs mass, the new physics could easily (but not necessarily) escape detection in the present and future accelerators.Comment: latex2e, 12 pages, 3 figure

Higgs Boson Bounds in Three and Four Generation Scenarios

In light of recent experimental results, we present updated bounds on the lightest Higgs boson mass in the Standard Model (SM) and in the Minimal Supersymmetric extension of the Standard Model (MSSM). The vacuum stability lower bound on the pure SM Higgs boson mass when the SM is taken to be valid up to the Planck scale lies above the MSSM lightest Higgs boson mass upper bound for a large amount of SUSY parameter space. If the lightest Higgs boson is detected with a mass M_{H} < 134 GeV (150 GeV) for a top quark mass M_{top} = 172 GeV (179 GeV), it may indicate the existence of a fourth generation of fermions. The region of inconsistency is removed and the MSSM is salvagable for such values of M_{H} if one postulates the existence of a fourth generation of leptons and quarks with isodoublet degenerate masses M_{L} and M_{Q} such that 60 GeV 170 GeV.Comment: 7 pages, 4 figures. To be published in Physical Review

A statistical approximation of common Roman ceramics from the Isturgi deposits (Andújar, Andalusia)

Common ceramics constitute a very abundant material in the archaeological record. This study focuses on analyzing and statistically interpreting, from the perspective of archaeological material culture, the features of Roman coarse-ware ceramics from the Isturgi deposits (Andújar, Andalusia). The main goal of this research was to study ceramics from an archaeological perspective with reference to quantitative and qualitative aspects. The fragments of pottery belong to three essential types - kitchenware, tableware, and pottery for storage and transportation - and have different characteristics. The data set consists of 3,626 fragments of ceramics of Roman origin, divided in three clearly differentiated groups: 1) common calcareous ceramics, b) oxidized kitchen ceramics, and 3) reduced kitchen ceramics, having a very different quantity of fragments (1,635; 1,714; and 277, respectively) distributed in 16 excavation zones. The analysis of the information has been carried out on the basis of univariate methods, analysis of correlation and regression, analysis of the variance (ANOVA) and multivariate factorial analysis (Factorial Analysis with Varimax Rotation mainly). In this form it is possible to characterize ceramics on the basis of whether they were fired in an oxidizing or a reducing atmosphere

Unconventional low-energy SUSY from warped geometry

Supersymmetric models with a warped fifth spatial dimension can solve the hierarchy problem, avoiding some shortcomings of non-supersymmetric constructions, and predict a plethora of new phenomena at typical scales Lambda not far from the electroweak scale (Lambda ~ a few TeV). In this paper we derive the low-energy effective theories of these models, valid at energies below Lambda. We find that, in general, such effective theories can deviate significantly from the Minimal Supersymmetric Standard Model (MSSM) or other popular extensions of it, like the NMSSM: they have non-minimal Kaehler potentials (even in the Mp -> \infty limit), and the radion is coupled to the visible fields, both in the superpotential and the Kaehler potential, in a non-trivial (and quite model-independent) fashion. The corresponding phenomenology is pretty unconventional, in particular the electroweak breaking occurs in a non-radiative way, with tan beta \simeq 1 as a quite robust prediction, while the mass of the lightest Higgs boson can be as high as ~ 700 GeV.Comment: 53 pages, 2 ps figure

Expectations for LHC from Naturalness: Modified vs. SM Higgs Sector

Common lore has it that naturalness of electroweak breaking in the SM requires new physics (NP) at Lambda < 2-3 TeV, hopefully within the reach of LHC. Moreover the Higgs should be light (m_h < 219 GeV) to pass electroweak precision tests (EWPT). However one should be prepared for "unexpected" (although admittedly unpleasant) results at LHC, i.e. no NP and/or a heavy Higgs. We revisit recent attempts to accommodate this by modifying the SM Higgs sector (using 2-Higgs-doublet models). We find that these models do not improve the naturalness of the SM, and so they do not change the expectations of observing NP at LHC. We also stress that a heavy SM Higgs would not be evidence in favour of a modified Higgs sector, provided certain higher order operators influence EWPT. On the other hand, we show that NP can escape LHC detection without a naturalness price, and with the pure SM as the effective theory valid at LHC energies, simply if the cut-off for top loops is slightly lower than for Higgs loops.Comment: 37 pages, LaTeX, 13 figure