Z' signals in polarised top-antitop final states

We study the sensitivity of top-antitop samples produced at all energy stages of the Large Hadron Collider (LHC) to the nature of an underlying Z' boson, in presence of full tree level standard model (SM) background effects and relative interferences. We concentrate on differential mass spectra as well as both spatial and spin asymmetries thereby demonstrating that exploiting combinations of these observables will enable one to distinguish between sequential Z's and those pertaining to Left-Right symmetric models as well as E6 inspired ones, assuming realistic final state reconstruction efficiencies and error estimates.Comment: 21 pages, 6 colour figures, 10 table

Warped Radion Dark Matter

Warped scenarios offer an appealing solution to the hierarchy problem. We consider a non-trivial deformation of the basic Randall-Sundrum framework that has a KK-parity symmetry. This leads to a stable particle beyond the Standard Model, that is generically expected to be the first KK-parity odd excitation of the radion field. We consider the viability of the KK-radion as a DM candidate in the context of thermal and non-thermal production in the early universe. In the thermal case, the KK-radion can account for the observed DM density when the radion decay constant is in the natural multi-TeV range. We also explore the effects of coannihilations with the first KK excitation of the RH top, as well as the effects of radion-Higgs mixing, which imply mixing between the KK-radion and a KK-Higgs (both being KK-parity odd). The non-thermal scenario, with a high radion decay constant, can also lead to a viable scenario provided the reheat temperature and the radion decay constant take appropriate values, although the reheat temperature should not be much higher than the TeV scale. Direct detection is found to be feasible if the DM has a small (KK-parity odd) Higgs admixture. Indirect detection via a photon signal from the galactic center is an interesting possibility, while the positron and neutrino fluxes from KK-radion annihilations are expected to be rather small. Colliders can probe characteristic aspects of the DM sector of warped scenarios with KK-parity, such as the degeneracy between the radion and the KK-radion (DM) modes.Comment: 43 pages, 16 figures; added reference

EFTfitter: A tool for interpreting measurements in the context of effective field theories

Over the past years, the interpretation of measurements in the context of effective field theories has attracted much attention in the field of particle physics. We present a tool for interpreting sets of measurements in such models using a Bayesian ansatz by calculating the posterior probabilities of the corresponding free parameters numerically. An example is given, in which top-quark measurements are used to constrain anomalous couplings at the Wtb-vertex.The authors would like to thank Fabian Bach, Kathrin Becker, Dominic Hirschbühl and Mikolaj Misiak for their help and for the fruitful discussions. In particular, the authors would like to thank Fabian Bach for providing the code for the single-top cross sections. N.C. acknowledges the support of FCT-Portugal through the contract IF/00050/2013/CP1172/CT00

Análisis del somatotipo de jugadores juveniles de fútbol asociación

The anthropometric characteristics of the subjects in association football were rarely considered in the selection of young soccer players in relation to their positions on the pitch. At present, in this sport it is becoming more and more frequent, as well as adding variables that contribute to the improvement of sports performance. Therefore, the main objective of this research is to identify and analyze the somatotype of amateur level players enrolled in the delfines academy who participate in the Veracruz soccer league, within the selection criteria of the participants is that they are in the age range of 14-17 years, they were evaluated for body composition through the bioimpedance technique (tanita tbf 300a, manual), with this the values ​​of weight, height, and BMI were obtained. Likewise, the anthropometry technique was obtained to obtain a complete profile of each player taking as a reference the calculation of the Heath - Carter somatotype, one of the results obtained is the prevalence of the endomorph somatotype for the forwards (2.87 ± 0. 76), defenders (2.99±0.55) and midfielders (2.55±0.47) and mesomorph: forwards (5.34±1.17), defenders (5.86±1.55) and midfielders (4.71±0.67), It was shown that the means present less mesomorphy and greater ectomorphy with (3.64±1.29). It is concluded from the results obtained that the predominance is of the balanced mesomorphic component, a situation that coincides with the results of other investigations, where the players of the amateur sector and professional soccer players according to the position they occupy on the pitch presenting a somatotype similar to those found in the studyLas características antropométricas de los sujetos en el fútbol asociación pocas veces eran consideradas en la selección de los jóvenes futbolistas en relación con sus posiciones dentro del terreno de juego. En la actualidad, en este deporte se hace cada vez más frecuente, así como sumar variables que coadyuvan a la mejora del rendimiento deportivo. Por tanto, el objetivo principal de esta investigación es identificar y analizar el somatotipo de jugadores de nivel amateur inscritos en la academia delfines que participa en la liga veracruzana de fútbol, dentro de los criterios de selección de los participantes es que estén en el rango de edad de 14-17 años, a ellos se les evaluación de composición corporal a través de la técnica de bioimpedancia (tanita tbf 300a, manual), con ello se obtuvieron los valores de peso, talla, IMC. Así mismo se utilizó la técnica de antropometría para obtener un perfil completo de cada jugador tomando como referencia el cálculo del somatotipo de Heath – Carter, alguno de los resultados obtenidos es la prevalencia del somatotipo de endomorfo para los delanteros (2,87±0,76), defensas (2.99±0,55) y medios campistas (2,55±0,47) y mesomorfo: delanteros (5,34±1,17), defensas (5,86±1,55) y medios campistas (4,71±0,67), Se observó que los medios presentan menor mesomorfia y mayor ectomorfia con (3,64 ±1,29). Se concluye por los resultados obtenidos que la predominancia es del componente mesomórfico balanceado, situación que coinciden con los resultados de otras investigaciones, donde los jugadores del sector amateur y jugadores de fútbol profesional de acuerdo a la posición que ocupan en el terreno de juego presentan un somatotipo similar a los hallazgos en el estudio

Beautiful Mirrors at the LHC

We explore the "Beautiful Mirrors" model, which aims to explain the measured value of $A^b_{FB}$, discrepant at the $2.9\sigma$ level. This scenario introduces vector-like quarks which mix with the bottom, subtly affecting its coupling to the $Z$. The spectrum of the new particles consists of two bottom-like quarks and a charge -4/3 quark, all of which have electroweak interactions with the third generation. We explore the phenomenology and discovery reach for these new particles at the LHC, exploring single mirror quark production modes whose rates are proportional to the same mixing parameters which resolve the $A_{FB}^b$ anomaly. We find that for mirror quark masses $\lesssim 500 GeV, a 14 TeV LHC with 300 {\rm fb}^{-1}$ is required to reasonably establish the scenario and extract the relevant mixing parameters.Comment: version to be published in JHE

Chiral U(1) flavor models and flavored Higgs doublets: the top FB asymmetry and the Wjj

We present U(1) flavor models for leptophobic Z' with flavor dependent couplings to the right-handed up-type quarks in the Standard Model, which can accommodate the recent data on the top forward-backward (FB) asymmetry and the dijet resonance associated with a W boson reported by CDF Collaboration. Such flavor-dependent leptophobic charge assignments generally require extra chiral fermions for anomaly cancellation. Also the chiral nature of U(1)' flavor symmetry calls for new U(1)'-charged Higgs doublets in order for the SM fermions to have realistic renormalizable Yukawa couplings. The stringent constraints from the top FB asymmetry at the Tevatron and the same sign top pair production at the LHC can be evaded due to contributions of the extra Higgs doublets. We also show that the extension could realize cold dark matter candidates.Comment: 40 pages, 10 figures, added 1 figure and extended discussion, accepted for publication in JHE

A Large Scale Double Beta and Dark Matter Experiment: GENIUS

The recent results from the HEIDELBERG-MOSCOW experiment have demonstrated the large potential of double beta decay to search for new physics beyond the Standard Model. To increase by a major step the present sensitivity for double beta decay and dark matter search much bigger source strengths and much lower backgrounds are needed than used in experiments under operation at present or under construction. We present here a study of a project proposed recently, which would operate one ton of 'naked' enriched GErmanium-detectors in liquid NItrogen as shielding in an Underground Setup (GENIUS). It improves the sensitivity to neutrino masses to 0.01 eV. A ten ton version would probe neutrino masses even down to 10^-3 eV. The first version would allow to test the atmospheric neutrino problem, the second at least part of the solar neutrino problem. Both versions would allow in addition significant contributions to testing several classes of GUT models. These are especially tests of R-parity breaking supersymmetry models, leptoquark masses and mechanism and right-handed W-boson masses comparable to LHC. The second issue of the experiment is the search for dark matter in the universe. The entire MSSM parameter space for prediction of neutralinos as dark matter particles could be covered already in a first step of the full experiment - with the same purity requirements but using only 100 kg of 76Ge or even of natural Ge - making the experiment competitive to LHC in the search for supersymmetry. The layout of the proposed experiment is discussed and the shielding and purity requirements are studied using GEANT Monte Carlo simulations. As a demonstration of the feasibility of the experiment first results of operating a 'naked' Ge detector in liquid nitrogen are presented.Comment: 22 pages, 12 figures, see also http://pluto.mpi-hd.mpg.de/~betalit/genius.htm

How are falls and fear of falling associated with objectively measured physical activity in a cohort of community-dwelling older men?

BACKGROUND: Falls affect approximately one third of community-dwelling older adults each year and have serious health and social consequences. Fear of falling (FOF) (lack of confidence in maintaining balance during normal activities) affects many older adults, irrespective of whether they have actually experienced falls. Both falls and fear of falls may result in restrictions of physical activity, which in turn have health consequences. To date the relation between (i) falls and (ii) fear of falling with physical activity have not been investigated using objectively measured activity data which permits examination of different intensities of activity and sedentary behaviour. METHODS: Cross-sectional study of 1680 men aged 71-92 years recruited from primary care practices who were part of an on-going population-based cohort. Men reported falls history in previous 12 months, FOF, health status and demographic characteristics. Men wore a GT3x accelerometer over the hip for 7 days. RESULTS: Among the 12% of men who had recurrent falls, daily activity levels were lower than among non-fallers; 942 (95% CI 503, 1381) fewer steps/day, 12(95% CI 2, 22) minutes less in light activity, 10(95% CI 5, 15) minutes less in moderate to vigorous PA [MVPA] and 22(95% CI 9, 35) minutes more in sedentary behaviour. 16% (n = 254) of men reported FOF, of whom 52% (n = 133) had fallen in the past year. Physical activity deficits were even greater in the men who reported that they were fearful of falling than in men who had fallen. Men who were fearful of falling took 1766(95% CI 1391, 2142) fewer steps/day than men who were not fearful, and spent 27(95% CI 18, 36) minutes less in light PA, 18(95% CI 13, 22) minutes less in MVPA, and 45(95% CI 34, 56) minutes more in sedentary behaviour. The significant differences in activity levels between (i) fallers and non-fallers and (ii) men who were fearful of falling or not fearful, were mediated by similar variables; lower exercise self-efficacy, fewer excursions from home and more mobility difficulties. CONCLUSIONS: Falls and in particular fear of falling are important barriers to older people gaining health benefits of walking and MVPA. Future studies should assess the longitudinal associations between falls and physical activity