57 research outputs found
Extracting the Strange Density from
We present a QCD analysis of the strange and charm contributions to the
neutrino deep inelastic structure function . We show that next-to-leading
order effects, which are relatively important for , play a lesser role in
the case of . The neutrino--antineutrino difference provides a new determination of the strange density, which
exhibits some advantages with respect to other traditional methods.Comment: 12 page
Extraction of TMDs with global fits
We present a brief review of our recent extractions of the Transverse-MomentumâDependent distribution and fragmentation functions performed by analysing
Semi-Inclusive Deep Inelastic Scattering and e+eâ â h1h2 + X data on azimuthal asymmetries
Comparing extractions of Sivers functions
A comparison is given of the various recently published extractions of the
Sivers functions from the HERMES and COMPASS data on single-transverse spin
asymmetries in semi-inclusive deeply inelastic scattering.Comment: Contribution to the proceedings of "The International Workshop on
Transverse Polarisation Phenomena in Hard Processes" (Transversity 2005),
Villa Olmo (Como), 7-10th. September 200
Implementation of an epicardial implantable MEMS sensor for continuous and real-time postoperative assessment of left ventricular activity in adult minipigs over a short- and long-term period
The sensing of left ventricular (LV) activity is fundamental in the diagnosis and monitoring of cardiovascular health in high-risk patients after cardiac surgery to achieve better short- and long-term outcome. Conventional approaches rely on noninvasive measurements even if, in the latest years, invasive microelectromechanical systems (MEMS) sensors have emerged as a valuable approach for precise and continuous monitoring of cardiac activity. The main challenges in designing cardiac MEMS sensors are represented by miniaturization, biocompatibility, and long-term stability. Here, we present a MEMS piezoresistive cardiac sensor capable of continuous monitoring of LV activity over time following epicardial implantation with a pericardial patch graft in adult minipigs. In acute and chronic scenarios, the sensor was able to compute heart rate with a root mean square error lower than 2 BPM. Early after up to 1 month of implantation, the device was able to record the heart activity during the most important phases of the cardiac cycle (systole and diastole peaks). The sensor signal waveform, in addition, closely reflected the typical waveforms of pressure signal obtained via intraventricular catheters, offering a safer alternative to heart catheterization. Furthermore, histological analysis of the LV implantation site following sensor retrieval revealed no evidence of myocardial fibrosis. Our results suggest that the epicardial LV implantation of an MEMS sensor is a suitable and reliable approach for direct continuous monitoring of cardiac activity. This work envisions the use of this sensor as a cardiac sensing device in closed-loop applications for patients undergoing heart surgery
The LHCSpin Project
LHCSpin aims at installing a polarized gas target in front of the LHCb
spectrometer, bringing, for the first time, polarized physics to the LHC. The
project will benefit from the experience achieved with the installation of an
unpolarized gas target at LHCb during the LHC Long Shutdown 2. LHCb will then
become the first experiment simultaneously running in collider and fixed-target
mode with polarized targets, opening a whole new range of explorations to its
exceptional spectrometer.
LHCSpin will offer a unique opportunity to probe polarized quark and gluon
parton distributions in nucleons and nuclei, especially at high and
intermediate , where experimental data are still largely missing. Beside
standard collinear parton distribution functions (PDFs), LHCSpin will make it
possible to study multidimensional polarized parton distributions that depend
also on parton transverse momentum.
The study of the multidimensional partonic structure of the nucleon,
particularly including polarization effects, can test our knowledge of QCD at
an unprecedented level of sophistication, both in the perturbative and
nonperturbative regime. At the same time, an accurate knowledge of hadron
structure is necessary for precision measurements of Standard Model (SM)
observables and discovery of physics beyond the SM.
Due to the intricate nature of the strong interaction, it is indispensable to
perform the widest possible suite of experimental measurements. It will be
ideal to have two new projects complementing each other: a new facility for
polarized electron-proton collisions and a new facility for polarized
proton-proton collisions. LHCSpin stands out at the moment as the most
promising candidate for the second type of project, going beyond the kinematic
coverage and the accuracy of the existent experiments, especially on the
heavy-quark sector
Photoproduction of mesons associated with a leading neutron
The photoproduction of mesons associated with a leading
neutron has been observed with the ZEUS detector in collisions at HERA
using an integrated luminosity of 80 pb. The neutron carries a large
fraction, {}, of the incoming proton beam energy and is detected at
very small production angles, { mrad}, an indication of
peripheral scattering. The meson is centrally produced with
pseudorapidity {
GeV}, which is large compared to the average transverse momentum of the neutron
of 0.22 GeV. The ratio of neutron-tagged to inclusive production is
in the photon-proton
center-of-mass energy range { GeV}. The data suggest that the
presence of a hard scale enhances the fraction of events with a leading neutron
in the final state.Comment: 28 pages, 4 figures, 2 table
- âŠ