20,170 research outputs found
Slepton mass splittings and cLFV in the SUSY seesaw in the light of recent experimental results
Following recent experimental developments, in this study we re-evaluate if
the interplay of high- and low-energy lepton flavour violating observables
remains a viable probe to test the high-scale type-I supersymmetric seesaw. Our
analysis shows that fully constrained supersymmetric scenarios no longer allow
to explore this interplay, since recent LHC data precludes the possibility of
having sizeable slepton mass differences for a slepton spectrum sufficiently
light to be produced, and in association to BR(mu -> e gamma) within
experimental reach. However, relaxing the strict universality of supersymmetric
soft-breaking terms, and fully exploring heavy neutrino dynamics, still allows
to have slepton mass splittings O(few %), for slepton masses accessible at the
LHC, with associated mu -> e gamma rates within future sensitivity. For these
scenarios, we illustrate how the correlation between high- and low-energy
lepton flavour violating observables allows to probe the high-scale
supersymmetric seesaw.Comment: 19 pages, 12 eps figures. References updated; matches version
accepted by JHE
Phenomenology of LFV at low-energies and at the LHC: strategies to probe the SUSY seesaw
We study the impact of a type-I SUSY seesaw concerning lepton flavour
violation (LFV) at low-energies and at the LHC. At the LHC, decays, in combination with other
observables, render feasible the reconstruction of the masses of the
intermediate sleptons, and hence the study of mass
differences. If interpreted as being due to the violation of lepton flavour,
high-energy observables, such as large slepton mass splittings and flavour
violating neutralino and slepton decays, are expected to be accompanied by
low-energy manifestations of LFV such as radiative and three-body lepton
decays. We discuss how to devise strategies based in the interplay of slepton
mass splittings as might be observed at the LHC and low-energy LFV observables
to derive important information on the underlying mechanism of LFV.Comment: 6 pages, 4 figures. To appear in the proceedings of the 11th
International Workshop on Tau Lepton Physics (TAU2010), Manchester, UK, 13-17
September 201
Lepton flavour violation: physics potential of a Linear Collider
We revisit the potential of a Linear Collider concerning the study of lepton
flavour violation, in view of new LHC bounds and of the (very) recent
developments in lepton physics. Working in the framework of a type I
supersymmetric seesaw, we evaluate the prospects of observing seesaw-induced
lepton flavour violating final states of the type e \mu + missing energy,
arising from e+ e- and e- e- collisions. In both cases we address the potential
background from standard model and supersymmetric charged currents. We also
explore the possibility of electron and positron beam polarisation. The
statistical significance of the signal, even in the absence of kinematical
and/or detector cuts, renders the observation of such flavour violating events
feasible over large regions of the parameter space. We further consider the
\mu-\mu- + E^T_miss final state in the e- e- beam option finding that, due to a
very suppressed background, this process turns out to be a truly clear probe of
a supersymmetric seesaw, assuming the latter to be the unique source of lepton
flavour violation.Comment: 30 pages, 48 figure
Potential of a Linear Collider for Lepton Flavour Violation studies in the SUSY seesaw
We study the potential of an e+- e- Linear Collider for charged lepton
flavour violation studies in a supersymmetric framework where neutrino masses
and mixings are explained by a type-I seesaw. Focusing on e-mu flavour
transitions, we evaluate the background from standard model and supersymmetric
charged currents to the e mu + missing E_T signal. We study the energy
dependence of both signal and background, and the effect of beam polarisation
in increasing the signal over background significance. Finally, we consider the
mu- mu- + missing E_T final state in e- e- collisions that, despite being
signal suppressed by requiring two e-mu flavour transitions, is found to be a
clear signature of charged lepton flavour violation due to a very reduced
standard model background.Comment: 8 pages, 5 figures. To appear in the proceedings of "DISCRETE 2012 -
3rd Symposium on Prospects in the Physics of Discrete Symmetries", Lisbon,
Portugal, 3-7 December 201
On Exact and Approximate Solutions for Hard Problems: An Alternative Look
We discuss in an informal, general audience style the da Costa-Doria conjecture about the independence of the P = NP hypothesis and try to briefly assess its impact on practical situations in economics. The paper concludes with a discussion of the Coppe-Cosenza procedure, which is an approximate, partly heuristic algorithm for allocation problems.P vs. NP , allocation problem, assignment problem, traveling salesman, exact solution for NP problems, approximate solutions for NP problems, undecidability, incompleteness
Metodologia cientÃfica: cultivo in vitro de unha-de-gato.
O uso da unha-de-gato como produto comercial (fitoterápico) apresenta algumas dificuldades, entre elas a falta de homogeneidade na constituição quÃmica das plantas comercializadas. Esse problema ocorre pelo fato da matéria-prima ser proveniente de áreas naturais sem nenhum controle de qualidade. Nesse sentido, a tecnologia de clonagem in vitro, apoiada por um trabalho de seleção de caracterÃsticas desejáveis, poderá contribuir para a obtenção de plantas com maior homogeneidade e de qualidade garantida.bitstream/item/99059/1/24058.PD
High Resolution 4.7 um Keck/NIRSPEC Spectra of Protostars. I: Ices and Infalling Gas in the Disk of L1489 IRS
We explore the infrared M band (4.7 um) spectrum of the class I protostar
L1489 IRS in the Taurus Molecular Cloud. This is the highest resolution wide
coverage spectrum at this wavelength of a low mass protostar observed to date
(R=25,000; Dv=12 km/s). Many narrow absorption lines of gas phase 12CO, 13CO,
and C18O are detected, as well as a prominent band of solid 12CO. The gas phase
12CO lines have red shifted absorption wings (up to 100 km/s), likely
originating from warm disk material falling toward the central object. The
isotopes and the 12CO line wings are successfully fitted with a contracting
disk model of this evolutionary transitional object (Hogerheijde 2001). This
shows that the inward motions seen in millimeter wave emission lines continue
to within ~0.1 AU from the star. The colder parts of the disk are traced by the
prominent CO ice band. The band profile results from CO in 'polar' ices (CO
mixed with H2O), and CO in 'apolar' ices. At the high spectral resolution, the
'apolar' component is, for the first time, resolved into two distinct
components, likely due to pure CO and CO mixed with CO2, O2 and/or N2. The ices
have probably experienced thermal processing in the upper disk layer traced by
our pencil absorption beam: much of the volatile 'apolar' ices has evaporated
and the depletion factor of CO onto grains is remarkably low (~7%). This study
shows that high spectral resolution 4.7 um observations provide important and
unique information on the dynamics and structure of protostellar disks and the
evolution of ices in these disks.Comment: 11 pages, 6 figures Scheduled to appear in ApJ 568 n2, 1 April 200
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