3,391 research outputs found
Search for Long-Lived Heavy Neutrinos at the LHC with a VBF Trigger
The charged current production of long-lived heavy neutrinos at the LHC can
use a prompt charged lepton for triggering the measurement of the process.
However, in order to fully characterize the heavy neutrino interactions, it is
necessary to also probe Higgs or mediated neutral current production. In
this case the charged lepton is not available, so other means of triggering are
required.
In this work, we explore the possibility of using a vector boson fusion
trigger in the context of a GeV-scale Type I Seesaw model. We consider a
minimal model, where both Higgs and Z-mediated contributions produce one heavy
neutrino, as well as an extended model where the Higgs can decay into two heavy
ones. Both scenarios are tested through displaced dilepton and displaced
multitrack jet searches.Comment: 31 pages, 1 appendix, 5 figures; v2: improved version, accepted for
publication in EPJ
Testing the goodness of fit of a hilbertian autoregressive model
The presented methodology for testing the goodness-of-fit of an
Autoregressive Hilbertian model (ARH(1) model) provides an infinite-dimensional
formulation of the approach proposed in Koul and Stute (1999), based on
empirical process marked by residuals. Applying a central and functional
central limit result for Hilbert-valued martingale difference sequences, the
asymptotic behavior of the formulated H-valued empirical process, also indexed
by H, is obtained under the null hypothesis. The limiting process is H-valued
generalized (i.e., indexed by H) Wiener process, leading to an asymptotically
distribution free test. Consistency is also analyzed. The case of misspecified
autocorrelation operator of the ARH(1) process is addressed as well. Beyond the
Euclidean setting, this approach allows to implement goodness of fit testing in
the context of manifold and spherical functional autoregressive processes
Temperature dependence of the anomalous effective action of fermions in two and four dimensions
The temperature dependence of the anomalous sector of the effective action of
fermions coupled to external gauge and pseudo-scalar fields is computed at
leading order in an expansion in the number of Lorentz indices in two and four
dimensions. The calculation preserves chiral symmetry and confirms that a
temperature dependence is compatible with axial anomaly saturation. The result
checks soft-pions theorems at zero temperature as well as recent results in the
literature for the pionic decay amplitude into static photons in the chirally
symmetric phase. The case of chiral fermions is also considered.Comment: RevTex, 19 pages, no figures. References adde
Modelización de la relación altura-diámetro para Pinus pinaster Ait. en Galicia mediante la función de densidad bivariante SBB
The bivariate density function SBB has been fitted to height and diameter data of maritime pine (Pinus pinaster Ait.) from 24 sample plots established in even-aged stands of this specie in Galicia (Northwestern Spain). The height-diameter model in maritime pine was estimated using a property of the SBB bivariate distribution. In order to get this, a median regression of SBB function was established between heights and diameters data of each one of the 24 sample plots. The estimated values obtained in the fit has also been used to obtain the curves corresponding to the percentiles of the 5 and 95 % of the height distribution. Finally, a generalized height-diameter function has been developed for Pinus pinaster in Galicia from the equations fitted to each plot, relating the SBB function with the principal stand variables.Se ha ajustado la función de densidad bivariante SBB a datos de altura y diámetro de una muestra de pies de pino marítimo (Pinus pinaster Ait.) pertenecientes a 24 parcelas de ensayo instaladas en masas regulares de dicha especie y repartidas por toda la Comunidad Autónoma de Galicia. Utilizando una propiedad de la distribución bivariante SBB se ha estimado la relación altura-diámetro en pino pinaster. Para ello se realizó un ajuste por regresión de medianas de la función SBB entre los datos de las alturas y los diámetros de los pies de cada una de las 24 parcelas inventariadas. Los estimadores obtenidos en el ajuste también han servido para obtener las curvas correspondientes a los percentiles del 5 y 95%de la distribución de alturas. Posteriormente, y a partir de la ecuación modelizada, se ha construido una función altura-diámetro generalizada, relacionando los parámetros de la función SBB con las principales variables de masa
Thermal Neutron Relative Biological Effectiveness Factors for Boron Neutron Capture Therapy from In Vitro Irradiations
The experimental determination of the relative biological effectiveness of thermal neutron
factors is fundamental in Boron Neutron Capture Therapy. The present values have been obtained
while using mixed beams that consist of both neutrons and photons of various energies. A common
weighting factor has been used for both thermal and fast neutron doses, although such an approach has
been questioned. At the nuclear reactor of the Institut Laue-Langevin a pure low-energy neutron beam
has been used to determine thermal neutron relative biological effectiveness factors. Different cancer
cell lines, which correspond to glioblastoma, melanoma, and head and neck squamous cell carcinoma,
and non-tumor cell lines (lung fibroblast and embryonic kidney), have been irradiated while using
an experimental arrangement designed to minimize neutron-induced secondary gamma radiation.
Additionally, the cells were irradiated with photons at a medical linear accelerator, providing reference
data for comparison with that from neutron irradiation. The survival and proliferation were studied
after irradiation, yielding the Relative Biological Effectiveness that corresponds to the damage of
thermal neutrons for the different tissue types.Asociacion Espanola Contra el Cancer (AECC)
PS16163811PORRSpanish MINECO
FIS2015-69941-C2-1-PJunta de Andalucia
P11-FQM-8229Campus of International Excellence BioTic
P-BS-64University of Granada Chair Neutrons for Medicine: the Spanish Fundacion ACSAsociacion Capitan AntonioFundacion ACSLa Kuadrilla de IznallozSonriendo Se Puede Gana
Radiobiology data of melanoma cells after low-energy neutron irradiation and boron compound administration
The cold neutron beam at the PF1b line at the Institut Laue-Langevin (ILL), without fast neutrons and a low contribution of gamma rays, is a very suitable facility to measure cell damage following low-energy neutron irradiation. The biological damage associated with the thermal and the boron doses can be obtained in order to evaluate the relative biological effectiveness (RBE) for Boron Neutron Capture Therapy. Three different experiments were carried out on the A375 melanoma cell line: the first one in a hospital LINAC, to obtain the reference radiation data, and the other two at the ILL, in which the damage to cells with and without boron compounds added was measured
VERTICAL DISTRIBUTION OF ANCHOVY EARLY STAGES IN THE ALBORAN SEA: VALIDATING TOOLS FOR IBM ECOLOGY IN A REGIONAL CONTEXT
Abstract We offer the first data on vertical distribution of anchovy larvae (Engraulis encrasicolus) in the Alboran Sea. Preliminary results show that the vast majority of anchovy larvae distributed in the top 25 m during daytime, suggesting either a lack of vertical migration or a type II migration. Data are discussed in the frame of the potential implications of vertical migration data for spatially -explicit individual-based model escercises being implemented in the are
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