174 research outputs found
Unified graphical summary of neutrino mixing parameters
The neutrino mixing parameters are presented in a number of different ways by the various experiments, e.g., SuperKamiokande, K2K, SNO, KamLAND, and CHOOZ, and also by the Particle Data Group. In this paper, we argue that presenting the data in terms of sin(2)theta, where theta is the mixing angle appropriate for a given experiment, has a direct physical interpretation. For current atmospheric, solar, and reactor neutrino experiments, the sin(2)theta's are effectively the probabilities of finding a given flavor in a particular neutrino mass eigenstate. The given flavor and particular mass eigenstate vary from experiment to experiment; however, the use of sin(2)theta provides a unified picture of all the data. Using this unified picture we present a graphical way to represent these neutrino mixing parameters which includes the uncertainties. All of this is performed in the context of the present experimental status of three neutrino oscillations
Flavor conversion of cosmic neutrinos from hidden jets
High energy cosmic neutrino fluxes can be produced inside relativistic jets
under the envelopes of collapsing stars. In the energy range E ~ (0.3 - 1e5)
GeV, flavor conversion of these neutrinos is modified by various matter effects
inside the star and the Earth. We present a comprehensive (both analytic and
numerical) description of the flavor conversion of these neutrinos which
includes: (i) oscillations inside jets, (ii) flavor-to-mass state transitions
in an envelope, (iii) loss of coherence on the way to observer, and (iv)
oscillations of the mass states inside the Earth. We show that conversion has
several new features which are not realized in other objects, in particular
interference effects ("L- and H- wiggles") induced by the adiabaticity
violation. The neutrino-neutrino scattering inside jet and inelastic neutrino
interactions in the envelope may produce some additional features at E > 1e4
GeV. We study dependence of the probabilities and flavor ratios in the
matter-affected region on angles theta13 and theta23, on the CP-phase delta, as
well as on the initial flavor content and density profile of the star. We show
that measurements of the energy dependence of the flavor ratios will, in
principle, allow to determine independently the neutrino and astrophysical
parameters.Comment: 56 pages, 19 figures. Minor changes. Accepted by JHEP
Leptonic CP Violation and Neutrino Mass Models
We discuss leptonic mixing and CP violation at low and high energies,
emphasizing possible connections between leptogenesis and CP violation at low
energies, in the context of lepton flavour models. Furthermore we analyse weak
basis invariants relevant for leptogenesis and for CP violation at low
energies. These invariants have the advantage of providing a simple test of the
CP properties of any lepton flavour model.Comment: 26 pages, no figures, submitted to the Focus Issue on `Neutrino
Physics` edited by F. Halzen, M. Lindner and A. Suzuki, to be published in
New Journal of Physic
Light Sterile Neutrinos: A White Paper
This white paper addresses the hypothesis of light sterile neutrinos based on
recent anomalies observed in neutrino experiments and the latest astrophysical
data
Stereoselective Synthesis of 2-Acetamido-1,2-dideoxyallonojirimycin (DAJNAc), a New Potent Hexosaminidase Inhibitor
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
Neutrino oscillation studies with IceCube-DeepCore
AbstractIceCube, a gigaton-scale neutrino detector located at the South Pole, was primarily designed to search for astrophysical neutrinos with energies of PeV and higher. This goal has been achieved with the detection of the highest energy neutrinos to date. At the other end of the energy spectrum, the DeepCore extension lowers the energy threshold of the detector to approximately 10 GeV and opens the door for oscillation studies using atmospheric neutrinos. An analysis of the disappearance of these neutrinos has been completed, with the results produced being complementary with dedicated oscillation experiments. Following a review of the detector principle and performance, the method used to make these calculations, as well as the results, is detailed. Finally, the future prospects of IceCube-DeepCore and the next generation of neutrino experiments at the South Pole (IceCube-Gen2, specifically the PINGU sub-detector) are briefly discussed
Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)
In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field
Multimessenger Gamma-Ray and Neutrino Coincidence Alerts using HAWC and IceCube sub-threshold Data
The High Altitude Water Cherenkov (HAWC) and IceCube observatories, through
the Astrophysical Multimessenger Observatory Network (AMON) framework, have
developed a multimessenger joint search for extragalactic astrophysical
sources. This analysis looks for sources that emit both cosmic neutrinos and
gamma rays that are produced in photo-hadronic or hadronic interactions. The
AMON system is running continuously, receiving sub-threshold data (i.e. data
that is not suited on its own to do astrophysical searches) from HAWC and
IceCube, and combining them in real-time. We present here the analysis
algorithm, as well as results from archival data collected between June 2015
and August 2018, with a total live-time of 3.0 years. During this period we
found two coincident events that have a false alarm rate (FAR) of
coincidence per year, consistent with the background expectations. The
real-time implementation of the analysis in the AMON system began on November
20th, 2019, and issues alerts to the community through the Gamma-ray
Coordinates Network with a FAR threshold of coincidences per year.Comment: 14 pages, 5 figures, 3 table
Reconstruction of interactions in the ProtoDUNE-SP detector with Pandora
The Pandora Software Development Kit and algorithm libraries provide
pattern-recognition logic essential to the reconstruction of particle
interactions in liquid argon time projection chamber detectors. Pandora is the
primary event reconstruction software used at ProtoDUNE-SP, a prototype for the
Deep Underground Neutrino Experiment far detector. ProtoDUNE-SP, located at
CERN, is exposed to a charged-particle test beam. This paper gives an overview
of the Pandora reconstruction algorithms and how they have been tailored for
use at ProtoDUNE-SP. In complex events with numerous cosmic-ray and beam
background particles, the simulated reconstruction and identification
efficiency for triggered test-beam particles is above 80% for the majority of
particle type and beam momentum combinations. Specifically, simulated 1 GeV/
charged pions and protons are correctly reconstructed and identified with
efficiencies of 86.1% and 84.1%, respectively. The efficiencies
measured for test-beam data are shown to be within 5% of those predicted by the
simulation.Comment: 39 pages, 19 figure
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