18 research outputs found
Point-source and diffuse high-energy neutrino emission from Type IIn supernovae
Type IIn supernovae (SNe), a rare subclass of core collapse SNe, explode in
dense circumstellar media that have been modified by the SNe progenitors at
their last evolutionary stages. The interaction of the freely expanding SN
ejecta with the circumstellar medium gives rise to a shock wave propagating in
the dense SN environment, which may accelerate protons to multi-PeV energies.
Inelastic proton-proton collisions between the shock-accelerated protons and
those of the circumstellar medium lead to multi-messenger signatures. Here, we
evaluate the possible neutrino signal of type IIn SNe and compare with IceCube
observations. We employ a Monte Carlo method for the calculation of the diffuse
neutrino emission from the SN IIn class to account for the spread in their
properties. The cumulative neutrino emission is found to be ~ 10 per cent of
the observed IceCube neutrino flux above 60 TeV. Type IIn SNe would be the
dominant component of the diffuse astrophysical flux, only if 4 per cent of all
core collapse SNe were of this type and 20 to 30 per cent of the shock energy
was channeled to accelerated protons. Lower values of the acceleration
efficiency are accessible by the observation of a single type IIn SN as a
neutrino point source with IceCube using up-going muon neutrinos. Such an
identification is possible in the first year following the SN shock breakout
for sources within 20 Mpc.Comment: 13 pages, 9 figures, MNRAS accepte
Connecting blazars with ultra high energy cosmic rays and astrophysical neutrinos
We present a strong hint of a connection between high energy -ray
emitting blazars, very high energy neutrinos, and ultra high energy cosmic
rays. We first identify potential hadronic sources by filtering -ray
emitters %from existing catalogs that are in spatial coincidence with the high
energy neutrinos detected by IceCube. The neutrino filtered -ray
emitters are then correlated with the ultra high energy cosmic rays from the
Pierre Auger Observatory and the Telescope Array by scanning in -ray
flux () and angular separation () between sources and
cosmic rays. A maximal excess of 80 cosmic rays (42.5 expected) is found at
from the neutrino filtered -ray emitters
selected from the second hard {\it Fermi}-LAT catalogue (2FHL) and for
.
The probability for this to happen is , which translates to
after compensation for all the considered trials. No
excess of cosmic rays is instead observed for the complement sample of
-ray emitters (i.e. not in spatial connection with IceCube neutrinos).
A likelihood ratio test comparing the connection between the neutrino filtered
and the complement source samples with the cosmic rays favours a connection
between neutrino filtered emitters and cosmic rays with a probability of
( after compensation for all the considered
trials. The neutrino filtered -ray sources that make up the cosmic rays
excess are blazars of the high synchrotron peak type. More statistics is needed
to further investigate these sources as candidate cosmic ray and neutrino
emitters.Comment: Accepted for publication in MNRAS, added one figure (redshift
distribution), new IceCube data, and penalty factor for subsets within single
catalogue
Fast adiabatic transport of single laser-cooled 9Be+ ions in a cryogenic Penning trap stack
High precision mass and g-factor measurements in Penning traps have enabled groundbreaking tests of fundamental physics. The most advanced setups use multi-trap methods, which employ transport of particles between specialized trap zones. Present developments focused on the implementation of sympathetic laser cooling will enable significantly shorter duty cycles and better accuracies in many of these scenarios. To take full advantage of these increased capabilities, we implement fast adiabatic transport concepts developed in the context of trapped-ion quantum information processing in a cryogenic Penning trap system. We show adiabatic transport of a single 9Be+ ion initially cooled to 2 mK over a 2.2-cm distance within 15 ms and with less than 10 mK energy gain at a peak velocity of 3 m/s. These results represent an important step towards the implementation of quantum logic spectroscopy in the (anti-)proton system. Applying these developments to other multi-trap systems has the potential to considerably increase the data-sampling rate in these experiments
Optical stimulated-Raman sideband spectroscopy of a single 9Be+ ion in a Penning trap
We demonstrate optical sideband spectroscopy of a single 9Be+ ion in a cryogenic 5 tesla Penning trap using two-photon stimulated-Raman transitions between the two Zeeman sublevels of the 1s22s ground state manifold. By applying two complementary coupling schemes, we accurately measure Raman resonances with and without contributions from motional sidebands. From the latter we obtain an axial sideband spectrum with an effective mode temperature of (3.1±0.4) mK. These results are a key step for quantum logic operations in Penning traps, applicable to high-precision matter-antimatter comparison tests in the baryonic sector of the standard model
Resolved-sideband cooling of a single Be ion in a Penning trap
Manipulating individual trapped ions at the single quantum level has become
standard practice in radio-frequency ion traps, enabling applications from
quantum information processing to precision metrology. The key ingredient is
ground-state cooling of the particle's motion through resolved-sideband laser
cooling. Ultra-high-presicion experiments using Penning ion traps will greatly
benefit from the reduction of systematic errors offered by full motional
control, with applications to atomic masses and -factor measurements,
determinations of fundamental constants or related tests of fundamental
physics. In addition, it will allow to implement quantum logic spectroscopy, a
technique that has enabled a new class of precision measurements in
radio-frequency ion traps. Here we demonstrate resolved-sideband laser cooling
of the axial motion of a single Be ion in a cryogenic 5 Tesla Penning
trap system using a two-photon stimulated-Raman process, reaching a mean phonon
number of . This is a fundamental step in the
implementation of quantum logic spectroscopy for matter-antimatter comparison
tests in the baryonic sector of the Standard Model and a key step towards
improved precision experiments in Penning traps operating at the quantum limit.Comment: 6 pages, 5 figure
Relationships Between Religion and Intolerance Towards Muslims and Immigrants in Europe:A Multilevel Analysis
This paper examines relationships between religiosity and intolerance towards Muslims and immigrants among Europeans living in non-Muslim majority countries by applying multilevel modeling to European Values Study data (wave four, 2010). Thus relationships across 44 national contexts are analyzed. The analysis found large between-country differences in the overall levels of intolerance towards immigrants and Muslims. Eastern Europeans tend to be more intolerant than Western Europeans. In most countries Muslims are less accepted than immigrants,—a finding which reflects that in post-9/11 Europe Islamophobia is prevalent and many still see Muslims with suspicion. A key result is that believing matters for the citizen’s attitudes towards Muslims and immigrants. Across Europe, traditional and modern fuzzy beliefs in a Higher Being are strongly negatively related to intolerance towards immigrants and Muslims, while fundamentalism is positively related to both targets of intolerance. Religious practice and denominational belonging on the other hand matter far less for the citizen’s propensity to dislike the two out-groups. With the only exception of non-devout Protestants who do not practice their religion, members of religious denominations are not more intolerant than non-members. The findings are valid for the vast majority of countries although countries differ in the magnitude of the effects
IceCube results from point-like source searches using 6 years of through-going muon data
The IceCube Neutrino Observatory located at the geographic South Pole was designed to study and discover high energy neutrinos coming from both galactic and extra-galactic astrophysical sources. Track-like events induced by charged-current muon-neutrino interactions close to the IceCube detector give an angular resolution better than 1∘ above TeV energies. We present here the results of searches for point-like astrophysical neutrino sources on the full sky using 6 years of detector livetime, of which three years use the complete IceCube detector. Within 2000 days of detector livetime, IceCube is sensitive to a steady flux substantially below E2∂ϕ/∂E = 10−12 TeV cm−2 s−1 in the northern sky for neutrino energies above 10 TeV
IceCube results from point-like source searches using 6 years of through-going muon data
The IceCube Neutrino Observatory located at the geographic South Pole was designed to study and discover high energy neutrinos coming from both galactic and extra-galactic astrophysical sources. Track-like events induced by charged-current muon-neutrino interactions close to the IceCube detector give an angular resolution better than 1∘ above TeV energies. We present here the results of searches for point-like astrophysical neutrino sources on the full sky using 6 years of detector livetime, of which three years use the complete IceCube detector. Within 2000 days of detector livetime, IceCube is sensitive to a steady flux substantially below E2∂ϕ/∂E = 10−12 TeV cm−2 s−1 in the northern sky for neutrino energies above 10 TeV