3,017 research outputs found
Double tailed scorpiand-type calix[10]phyrin: Synthesis and proton-driven anion recognition features
Reported here is a large oligopyrrole macrocycle, a calix[10]phyrin bearing two diformyl substituents. The combination of conjugation provided by two pentapyrrolic subunits and flexibility resulting from the presence of sp3 hybridized meso bridges allows the system to adopt a double tailed, scorpiand-like structure with two near-symmetric binding pockets. In methanol solution, this macrocycle was found to interact with a number of test acids, including sulfuric acid, trifluoroacetic acid, phosphoric acid, hydrochloric acid, and fluoroboric acid, via a combination of protonation and counter anion binding. Species specific behavior was seen, allowing for the colorimetric-based discrimination between the acids. Efforts to model the underlying binding equilibria led to the conclusion that upon treatment with excess H2SO4, up to four protons and two counteranions are bound, whereas in the case of HCl the dominant species is a monoanionic complex. The responses of several other acids were rationalized in terms of these limiting scenarios
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 , discrepant at the level. This scenario
introduces vector-like quarks which mix with the bottom, subtly affecting its
coupling to the . 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 anomaly. We find that for mirror quark
masses 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
- …