Coconut and sunflower oil ratios in ice cream influence subsequent food selection and intake

The effect of coconut oil (CO, containing mainly medium chain triglycerides - MCTs) and sunflower oil (SO, containing mainly long chain triglycerides - LCTs) used as fat source (10% fat ice cream) in different ratios (25% CO and 75% SO - 25CO:75SO, 50% CO and 50% SO - 50CO:50SO, 75% CO and 25% SO - 75CO:25SO) was investigated to assess differences in appetite and ad-libitum (evening and snack) food intake using a single blind design. 36 healthy female participants consumed a fixed portion (150 g) of ice cream 45 min before an ad-libitum dinner and snacks. Appetite sensations were tracked across the day. Participants ate significantly less fat after 75CO:25SO than 25CO:75SO (p = 0.007) and there was also a trend for lower fat intake in this condition as compared to 50CO:50SO (p = 0.068). High fat savoury snack intake significantly decreased after 75CO:25SO in comparison with both 25CO:75SO (p = 0.038) and 50CO:50SO (p = 0.008). Calorie intake from snacks was also found to be significantly lower after 25CO:75SO and 50CO:50SO than 75CO:25SO (p = 0.021 and 0.030 respectively). There was no effect of condition on appetite or desire ratings over the day. Eating a standard portion of ice cream containing different ratios of MCTs and LCTs can modestly influence acute food selection and intake, with MCTs manifesting their effect earlier and LCTs later due to differences in the absorption and metabolism of these lipids. However, the differences evident in the present study were small, and require further research before firm conclusions can be drawn

Constraints on the pMSSM from LAT Observations of Dwarf Spheroidal Galaxies

We examine the ability for the Large Area Telescope (LAT) to constrain Minimal Supersymmetric Standard Model (MSSM) dark matter through a combined analysis of Milky Way dwarf spheroidal galaxies. We examine the Lightest Supersymmetric Particles (LSPs) for a set of ~71k experimentally valid supersymmetric models derived from the phenomenological-MSSM (pMSSM). We find that none of these models can be excluded at 95% confidence by the current analysis; nevertheless, many lie within the predicted reach of future LAT analyses. With two years of data, we find that the LAT is currently most sensitive to light LSPs (m_LSP < 50 GeV) annihilating into tau-pairs and heavier LSPs annihilating into b-bbar. Additionally, we find that future LAT analyses will be able to probe some LSPs that form a sub-dominant component of dark matter. We directly compare the LAT results to direct detection experiments and show the complementarity of these search methods.Comment: 24 pages, 9 figures, submitted to JCA

Enhancement of Loop Induced H±W∓Z0H^\pm W^\mp Z^0 Vertex in Two Higgs-doublet Model

The non-decoupling effects of heavy Higgs bosons as well as fermions on the loop-induced $H^\pm W^\mp Z^0$ vertex are discussed in the general two Higgs doublet model. The decay width of the process $H^+ \to W^+ Z^0$ is calculated at one-loop level and the possibility of its enhancement is explored both analytically and numerically. We find that the novel enhancement of the decay width can be realized by the Higgs non-decoupling effects with large mass-splitting between the charged Higgs boson and the CP-odd one. This is due to the large breakdown of the custodial $SU(2)_V$ invariance in the Higgs sector. The branching ratio can amount to $10^{-2} \sim 10^{-1}$ for $m_{H^\pm} = 300$ GeV within the constraint from the present experimental data. Hence this mode may be detectable at LHC or future $e^+e^-$ linear colliders.Comment: 31+1 pages, Latex with 8 eps-file

Chromomagnetic Dipole Moment of the Top Quark Revisited

We study the complete one-loop contributions to the chromagnetic dipole moment $\Delta\kappa$ of the top quark in the Standard Model, two Higgs doublet models, topcolor assited technicolor models (TC2), 331 models and extended models with a single extra dimension. We find that the SM predicts $\Delta\kappa = - 0.056$ and that the predictions of the other models are also consitent with the constraints imposed on $\Delta\kappa$ by low-energy precision measurements.Comment: 20 pages, 5 figures, Updat

Combined analysis of Z' -> t tbar and Z' -> t tbar j production for vector resonance searches at LHC

We have implemented a code for Z' + n jets production in ALPGEN, with Z' decays into several final states, including l+ l- and t tbar. The MLM prescription is used for matching the matrix element with the parton shower, including in this way the leading soft and collinear corrections. In order to demonstrate its capabilities, we perform a combined analysis of Z' -> t tbar and Z' -> t tbar j production for a heavy leptophobic gauge boson. It is found that the effect of the extra jet cannot only be accounted for by a K factor multiplying the leading-order cross section. In fact, the combined analysis for Z' -> t tbar and Z' -> t tbar j presented improves the statistical significance of the signal by 25% (8.55 sigma versus 6.77 sigma for a Z' mass of 1 TeV), compared with the results of an inclusive analysis carried out on the same sample of t tbar + t tbar j events.Comment: LaTeX 17 pages, 13 PS figure

The muon g-2 in a SU(7) left-right symmetric model with mirror fermions

We have studied a left-right symmetric model with mirror fermions based in a grand unified SU(7) model in order to account for the muon anomaly. The Higgs sector of the model contains two Higgs doublets and the hierarchy condition $\upsilon_{L}\ll\upsilon_{R}$ can be achieved by using two additional Higgs singlets, one even and other odd under $\mathcal{D}$-parity. We show that there is a wide range of values for the mass parameters of the model that is consistent with the $g-2$ lepton anomalies. Radiative correction to the mass of the ordinary fermions are shown to be small

Magnetization dynamics with a spin-transfer torque

The magnetization reversal and dynamics of a spin valve pillar, whose lateral size is 64$\times$64 nm$^2$, are studied by using micromagnetic simulation in the presence of spin transfer torque. Spin torques display both characteristics of magnetic damping (or anti-damping) and of an effective magnetic field. For a steady-state current, both M-I and M-H hysteresis loops show unique features, including multiple jumps, unusual plateaus and precessional states. These states originate from the competition between the energy dissipation due to Gilbert damping and the energy accumulation due to the spin torque supplied by the spin current. The magnetic energy oscillates as a function of time even for a steady-state current. For a pulsed current, the minimum width and amplitude of the spin torque for achieving current-driven magnetization reversal are quantitatively determined. The spin torque also shows very interesting thermal activation that is fundamentally different from an ordinary damping effect.Comment: 15 figure

Constraining Supergravity Scenarios through the b→s,γb\to s,\gamma Decay.

We evaluate the branching ratio BR($b\rightarrow s,\gamma$) in the minimal supersymmetric standard model (MSSM), determining the corresponding phenomenological restrictions on two attractive supergravity scenarios, namely minimal supergravity and a class of models with a natural solution to the $\mu$ problem. We have included in the calculation some one--loop refinements that have a substantial impact on the results. The numerical results show some disagreements with part of the previous results in the literature, while they are in agreement with others. For minimal supergravity the CLEO upper and lower bounds put important restrictions on the scalar and gaugino masses in both cases $\mu0$. For the other supergravity scenarios the relevant CLEO bound is the upper one. It is stressed the fact that an eventual improvement of the experimental bounds of order $10^{-4}$ would strengthen the restrictions on the MSSM dramatically. This would be enough to discard these supergravity scenarios with $\mu<0$ if no discrepancy is found with the standard model prediction, while for $\mu>0$ there will remain low-energy windows.Comment: 13 pages + 8 figures included in a separate file, Latex, requires psfig.sty. We have corrected a mistake affecting some figures and their corresponding quotations in the text, as well as several misprints

FCNC Top Quark Decays in Extra Dimensions

The flavor changing neutral top quark decay t -> c X is computed, where X is a neutral standard model particle, in a extended model with a single extra dimension. The cases for the photon, X= \gamma$, and a Standard Model Higgs boson, X = H, are analyzed in detail in a non-linear$R_\xi gauge. We find that the branching ratios can be enhanced by the dynamics originated in the extra dimension. In the limit where 1/R >> ->, we have found Br(t -> c \gamma) \simeq 10^{-10} for 1/R = 0.5 TeV. For the decay t -> c H, we have found Br(t -> cH) \simeq 10^{-10} for a low Higgs mass value. The branching ratios go to zero when 1/R -> \infty.Comment: Accepted to be published in the Europ. Phys. Jour. C; 16 pages, 2 figure