Search results for "Armed"
showing 10 items of 115 documents
Λb→J/ψKΞdecay and the higher order chiral terms of the meson baryon interaction
2015
We study the weak decay of the ${\mathrm{\ensuremath{\Lambda}}}_{b}$ into $J/\ensuremath{\psi}K\mathrm{\ensuremath{\Xi}}$ and $J/\ensuremath{\psi}\ensuremath{\eta}\mathrm{\ensuremath{\Lambda}}$ states, and relate these processes to the ${\mathrm{\ensuremath{\Lambda}}}_{b}\ensuremath{\rightarrow}J/\ensuremath{\psi}\overline{K}N$ decay mode. The elementary weak transition at the quark level proceeds via the creation of a $J/\ensuremath{\psi}$ meson and an excited $sud$ system with $I=0$, which upon hadronization leads to $\overline{K}N$ or $\ensuremath{\eta}\mathrm{\ensuremath{\Lambda}}$ pairs. These states undergo final-state interaction in coupled channels and produce a final meson-baryon p…
Search for CP violation using T-odd correlations in D-0 -> K+K-pi(+)pi(-) decays
2014
A search for $CP$ violation using $T$-odd correlations is performed using the four-body $D^0 \to K^+K^-\pi^+\pi^-$ decay, selected from semileptonic $B$ decays. The data sample corresponds to integrated luminosities of $1.0\,\text{fb}^{-1}$ and $2.0\,\text{fb}^{-1}$ recorded at the centre-of-mass energies of 7 TeV and 8 TeV, respectively. The $CP$-violating asymmetry $a_{CP}^{T\text{-odd}}$ is measured to be $(0.18\pm 0.29\text{(stat)}\pm 0.04\text{(syst)})\%$. Searches for $CP$ violation in different regions of phase space of the four-body decay, and as a function of the $D^0$ decay time, are also presented. No significant deviation from the $CP$ conservation hypothesis is found.
Electromagnetic transitions of heavy baryons in theSU(2Nf)⊗O(3)symmetry
2001
We apply heavy quark symmetry to the radiative decays of heavy baryons. Even with this symmetry in place there are too many couplings to make a meaningful set of predictions. We show that if, in addition, light-diquark symmetries are applied, the number of electromagnetic couplings among S wave and P wave states as well as those between P wave to S wave transitions can be reduced significantly. Using this constituent quark model picture a number of predictions are made that will be testable in the near future.
Search for the decayB¯0→Λc+p¯pp¯
2014
We report a search for the decay B^0 → Λ^+_cppp. Using a data sample of 471×10^6 BB pairs collected with the BABAR detector at the PEP-II2 storage ring at SLAC, we find no events and set an upper limit on the branching fraction B(B^0 → Λ^+_cppp)×^(B(Λ^+_c→pK^−π^+))_(0.050) <2.8×10^(−6) at 90% C.L., where we have normalized B(Λ^+_c → pK^−π^+) to the world average value.
La disputa fronteriza entre India y China: origen y evolución de la controversia
2008
Con la emergencia de la India independiente y de la China maoísta a mediados del siglo pasado, los dos nuevos gobiernos de Delhi y Pekín comenzaron a convivir en un marco de armonía bajo los principios de coexistencia pacífica y una política de hermandad entre ambos pueblos, conocida como Hindi-Chini Bhai Bhai. Sin embargo, a pesar de estas actitudes amistosas iniciales, la herencia colonial británica en la India y las consecuencias de la anexión china del territorio tibetano, vinieron a desestabilizar este equilibrio, con el enfrentamiento de las pretensiones soberanistas de ambos Estados emergentes sobre distintas zonas fronterizas.El análisis del origen y la evolución de la controvertida…
The transient gravitational-wave sky
2013
Interferometric detectors will very soon give us an unprecedented view of the gravitational-wave sky, and in particular of the explosive and transient Universe. Now is the time to challenge our theoretical understanding of short-duration gravitational-wave signatures from cataclysmic events, their connection to more traditional electromagnetic and particle astrophysics, and the data analysis techniques that will make the observations a reality. This paper summarizes the state of the art, future science opportunities, and current challenges in understanding gravitational-wave transients.
Camino a la paz: repertorios simbólicos testimoniales de una nación en transición
2016
Resumen : En Colombia se han dado en los ultimos anos una variedad de repertorios simbolicos de memorias del trauma que ha vivido el pais como resultado del conflicto armado. Estos repertorios se manifiestan en diversas expresiones culturales y esteticas con el fin de interpelar y transformar las experiencias sufridas por las victimas de la violencia. Son practicas de reparacion y resistencia como antidoto contra la impunidad y el olvido. En este ensayo se propone que los repertorios simbolicos son las nuevas formas del testimonio del siglo veintiuno. Dichos repertorios se apropian de los metodos y estrategias del testimonio para expresar una urgencia y una solidaridad hacia un objetivo com…
The use of armed drones for counter-terrorism purposes: whether customary international law?
2019
The vast and rapid development of technologies constantly creates gaps in the law within both the international and national law systems. One of such technologies the increased usage of which for military purposes has instituted a debate on the applicable law for its use under the existing legal frameworks is the technology of armed drones, also known as armed unmanned aerial vehicles (AUAVs). The source of the debate is the presumption that armed drones are almost exclusively used for counter-terrorism purposes, thus involving their use against non-state actors operating in a country that a state is not in war with. The author of this thesis will, first of all, identify the established leg…
s-wave charmed baryon resonances from a coupled-channel approach with heavy quark symmetry
2009
We study charmed baryon resonances which are generated dynamically within a unitary meson-baryon coupled channel model that treats the heavy pseudoscalar and vector mesons on equal footing as required by heavy-quark symmetry. It is an extension of recent SU(4) models with t-channel vector meson exchanges to a SU(8) spin-flavor scheme, but differs considerably from the SU(4) approach in how the strong breaking of the flavor symmetry is implemented. Some of our dynamically generated states can be readily assigned to recently observed baryon resonances, while others do not have a straightforward identification and require the compilation of more data as well as an extension of the model to d-w…
The effects of armed conflict on schooling in Sub-Saharan Africa
2012
In the past decades, most of the countries in sub-Saharan Africa have been affected by armed conflicts. By means of a time-series cross-sectional (TSCS) database, we attempt to measure the impact of war on a sample of 43 countries in Africa from 1950 to 2010. These conflicts, and especially civil wars, are shown to have a strong negative effect on the educational performances of the countries studied. The rate of children not attending school, as well as secondary school enrollment rates, seems particularly sensitive to periods of conflict. It also appears that government expenditures in social sectors including education are a positive factor in increasing school enrollment. In contrast, m…