32,542,214 research outputs found
Images of the Early Universe from the BOOMERanG experiment
The CMB is the fundamental tool to study the properties of the early universe and of the
universe at large scales. In the framework of the Hot Big Bang model, when we look to
the CMB we look back in time to the end of the plasma era, at a redshift ~ 1000, when
the universe was ~ 50000 times younger, ~ 1000 times hotter and ~ 10^9 times denser
than today. The image of the CMB can be used to study the physical processes there, to
infer what happened before, and also to study the background geometry of our Universe
Measurement of the multi-TeV neutrino cross section with IceCube using Earth absorption
Neutrinos interact only very weakly, so they are extremely penetrating.
However, the theoretical neutrino-nucleon interaction cross section rises with
energy such that, at energies above 40 TeV, neutrinos are expected to be
absorbed as they pass through the Earth. Experimentally, the cross section has
been measured only at the relatively low energies (below 400 GeV) available at
neutrino beams from accelerators \cite{Agashe:2014kda, Formaggio:2013kya}. Here
we report the first measurement of neutrino absorption in the Earth, using a
sample of 10,784 energetic upward-going neutrino-induced muons observed with
the IceCube Neutrino Observatory. The flux of high-energy neutrinos transiting
long paths through the Earth is attenuated compared to a reference sample that
follows shorter trajectories through the Earth. Using a fit to the
two-dimensional distribution of muon energy and zenith angle, we determine the
cross section for neutrino energies between 6.3 TeV and 980 TeV, more than an
order of magnitude higher in energy than previous measurements. The measured
cross section is (stat.) (syst.)
times the prediction of the Standard Model \cite{CooperSarkar:2011pa},
consistent with the expectation for charged and neutral current interactions.
We do not observe a dramatic increase in the cross section, expected in some
speculative models, including those invoking new compact dimensions
\cite{AlvarezMuniz:2002ga} or the production of leptoquarks
\cite{Romero:2009vu}.Comment: Preprint version of Nature paper 10.1038/nature2445
ℓ-space spectroscopy of the Cosmic Microwave Background with the BOOMERanG experiment
The BOOMERanG experiment has recently produced detailed maps of the Cosmic Microwave Background, where sub-horizon structures are resolved with good signal to noise ratio. A power spectrum (spherical harmonics) analysis of the maps detects three peaks, at multipoles ℓ = (213_(-13)^(+10)),(541_(-32)^(+20))(845_(-25)^(+12)). In this paper we discuss the data analysis and the implications of these results for cosmology
Quantum numbers of the state and orbital angular momentum in its decay
Angular correlations in decays, with , and , are used to measure
orbital angular momentum contributions and to determine the value of
the meson. The data correspond to an integrated luminosity of 3.0
fb of proton-proton collisions collected with the LHCb detector. This
determination, for the first time performed without assuming a value for the
orbital angular momentum, confirms the quantum numbers to be .
The is found to decay predominantly through S wave and an upper limit
of at C.L. is set on the fraction of D wave.Comment: 16 pages, 4 figure
Direct gaze modulates face recognition in young infants
From birth, infants prefer to look at faces that engage them in direct eye contact. In adults, direct gaze is known to modulate the processing of faces, including the recognition of individuals. In the present study, we investigate whether direction of gaze has any effect on face recognition in four-month-old infants. Four-month infants were shown faces with both direct and averted gaze, and subsequently given a preference test involving the same face and a novel one. A novelty preference during test was only found following initial exposure to a face with direct gaze. Further, face recognition was also generally enhanced for faces with both direct and with averted gaze when the infants started the task with the direct gaze condition. Together, these results indicate that the direction of the gaze modulates face recognition in early infancy
Light (anti-)nuclei production and elliptic flow at the LHC with ALICE
Results on the production of stable light nuclei, including deuterons,
He-3, He-4 and the corresponding anti-nuclei, in Pb-Pb collisions at
root s(NN) = 2.76 TeV and root s(NN) = 5.02 TeV are presented and
compared with theoretical predictions and with the results in small
systems to provide insight into the production mechanisms of
(anti-)nuclei at colliders.
The experimental results are presented giving a critical view of their
comparison to the expectations from coalescence and hydrodynamic models
that aim at describing both the p(T)-spectra and the elliptic flow
Guidelines on the management of valvular heart disease: The Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology.
80These guidelines focus on valvular heart disease in adults and adolescents, are
oriented towards management, and will not deal with endocarditis
and congenital valve diseases in adults and
adolescents, since recent guidelines have been produced
by the ESC on these topics. Although valvular heart disease is less common in
industrialized countries than coronary disease, heart
failure, or hypertension, guidelines are needed in this
field for several reasons: valvular heart disease is common and often requires intervention; substantial advances have been made in the understanding
of its pathophysiology; the patient population has changed with a continuous
decline of acute rheumatic fever and an increased
incidence
of degenerative valvular diseases in industrialized
countries. The incidence of endocarditis remains stable and
other causes of valve disease are rare. Because of the predominance
of degenerative valve disease, the two most frequent
valve diseases are now calcific aortic stenosis and
mitral regurgitation. Aortic regurgitation and mitral stenosis have become less common. Diagnosis is now dominated by echocardiography, which
has become the standard to evaluate valve structure and
function. Treatment has not only developed through the continuing
progress in prosthetic valve technology, but has also been
reoriented by the development of conservative surgical
approaches and the introduction of percutaneous interventional
techniques.openopenVahanian, A; Baumgartner, ; H, ; Bax, ; J, ; Butchart, ; E, ; Dion, ; R, ; Filippatos, ; G, ; Flachskampf, ; F, ; Hall, ; R, ; Iung, ; B, ; Kasprzak, ; J, ; Nataf, ; P, ; Tornos, ; P, ; Torracca, ; L, ; Wenink, ; A, ; Silvia, ; Priori, G.; Blanc, Jean-Jacques; Andrzej, ; Budaj, ; John, ; Camm, ; Veronica, ; Dean, ; Jaap, ; Deckers, ; Kenneth, ; Dickstein, ; John, ; Lekakis, ; Keith, ; Mcgregor, ; Marco, ; Metra, ; João, ; Morais, ; Ady, ; Osterspey, ; Juan, ; Tamargo, ; Luis, José; Zamorano, ; Annalisa, ; Angelini, ; Manuel, ; Antunes, ; Angel, Miguel; Fernandez, Garcia; Christa, ; Gohlke-Baerwolf, ; Gilbert, ; Habib, ; John, ; Mcmurray, ; Catherine, ; Otto, ; Luc, ; Pierard, ; Josè, ; Pomar, L.; Bernard, ; Prendergast, ; Raphael, ; Rosenhek, ; Sousa, Miguel; Uva, ; Juan, ; Tamargo,Vahanian, A; Baumgartner, ; H, ; Bax, ; J, ; Butchart, ; E, ; Dion, ; R, ; Filippatos, ; G, ; Flachskampf, ; F, ; Hall, ; R, ; Iung, ; B, ; Kasprzak, ; J, ; Nataf, ; P, ; Tornos, ; P, ; Torracca, ; L, ; Wenink, ; A, ; Silvia, ; Priori, G.; Blanc, Jean Jacques; Andrzej, ; Budaj, ; John, ; Camm, ; Veronica, ; Dean, ; Jaap, ; Deckers, ; Kenneth, ; Dickstein, ; John, ; Lekakis, ; Keith, ; Mcgregor, ; Marco, ; Metra, Marco; João, ; Morais, ; Ady, ; Osterspey, ; Juan, ; Tamargo, ; Luis, José; Zamorano, ; Annalisa, ; Angelini, ; Manuel, ; Antunes, ; Angel, Miguel; Fernandez, Garcia; Christa, ; Gohlke, Baerwolf; Gilbert, ; Habib, ; John, ; Mcmurray, ; Catherine, ; Otto, ; Luc, ; Pierard, ; Josè, ; Pomar, L.; Bernard, ; Prendergast, ; Raphael, ; Rosenhek, ; Sousa, Miguel; Uva, ; Juan, ; Tamargo
Spin alignment measurements using vector mesons with ALICE detector at the LHC
We present new measurements related to spin alignment of K*(0) vector
mesons at mid-rapidity for Pb-Pb collisions at root s(NN) = 2.76 and
5.02 TeV. The spin alignment measurements are carried out with respect
to production plane and 2nd order event plane. At low p(T) the spin
density matrix element rho(00) for K*(0) is found to have values
slightly below 1/3, while it is consistent with 1/3, i.e. no spin
alignment, at high p(T). Similar values of rho(00) are observed with
respect to both production plane and event plane. Within statistical and
systematic uncertainties, rho(00) values are also found to be
independent of root s(NN). rho(00) also shows centrality dependence with
maximum deviation from 1/3 for mid-central collisions with respect to
both the kinematic planes. The measurements for K*(0) in pp collisions
at root s = 13 TeV and for K-s(0) (a spin 0 hadron) in 20-40\% central
Pb-Pb collisions at root s(NN) = 2.76 TeV are consistent with no spin
alignment
Muon physics at forward rapidity with the ALICE detector upgrade
ALICE is the experiment specifically designed to study the Quark-Gluon
Plasma (QGP) in heavy-ion collisions at the CERN LHC. The ALICE detector
will be upgraded during the Long Shutdown 2, planned for 2019-2020, in
order to cope with the maximum interaction rate of 50 kHz of Pb-Pb
collisions foreseen for Runs 3 and 4. The ambitious programme of
high-precision measurements, expected for muon physics after 2020,
requires an upgrade of the front-end and readout electronics of the
existing Muon Spectrometer. This concerns the Cathode Pad Chambers (CPC)
used for tracking and the Resistive Plate Chambers (RPC) used for
triggering and for muon identification. The Muon Forward Tracker (MFT),
an internal tracker added in front of the front absorber of the existing
Muon Spectrometer, is also part of the ALICE detector upgrade programme.
It is based on an assembly of circular planes made of Monolithic Active
Pixel Sensors (MAPS), covering the pseudorapidity range 2.5 < eta < 3.6.
The MFT will improve present measurements and enable new ones. A
selection of results from physics performance studies will be presented,
together with an overview of the technical aspects of the upgrade
project
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