4,299 research outputs found
A Linear Iterative Unfolding Method
A frequently faced task in experimental physics is to measure the probability
distribution of some quantity. Often this quantity to be measured is smeared by
a non-ideal detector response or by some physical process. The procedure of
removing this smearing effect from the measured distribution is called
unfolding, and is a delicate problem in signal processing, due to the
well-known numerical ill behavior of this task. Various methods were invented
which, given some assumptions on the initial probability distribution, try to
regularize the unfolding problem. Most of these methods definitely introduce
bias into the estimate of the initial probability distribution. We propose a
linear iterative method, which has the advantage that no assumptions on the
initial probability distribution is needed, and the only regularization
parameter is the stopping order of the iteration, which can be used to choose
the best compromise between the introduced bias and the propagated statistical
and systematic errors. The method is consistent: "binwise" convergence to the
initial probability distribution is proved in absence of measurement errors
under a quite general condition on the response function. This condition holds
for practical applications such as convolutions, calorimeter response
functions, momentum reconstruction response functions based on tracking in
magnetic field etc. In presence of measurement errors, explicit formulae for
the propagation of the three important error terms is provided: bias error,
statistical error, and systematic error. A trade-off between these three error
terms can be used to define an optimal iteration stopping criterion, and the
errors can be estimated there. We provide a numerical C library for the
implementation of the method, which incorporates automatic statistical error
propagation as well.Comment: Proceedings of ACAT-2011 conference (Uxbridge, United Kingdom), 9
pages, 5 figures, changes of corrigendum include
Signals of Disoriented Chiral Condensate
If a disoriented chiral condensate is created over an extended space-time
region following a rapid cooling in hadronic or nuclear collisions, the
misalignment of the condensate with the electroweak symmetry breaking can
generate observable effects in the processes which involve both strong and
electromagnetic interactions. We point out the relevance of the dilepton decay
of light vector mesons as a signal for formation of the disoriented condensate.
We predict that the decay \rho^0 to dileptons will be suppressed and/or the
\rho resonance peak widens, while the decay \omega to dileptons will not be
affected by the condensate.Comment: 13 pages in LaTeX, UCB-PTH-94/05, LBL-3533
EU-Funded Telemedicine Projects – Assessment of, and Lessons Learned From, in the Light of the SARS-CoV-2 Pandemic
The SARS-CoV-2 health emergency has demonstrated the need for developing structured telemedicine systems to protect citizens from the spread of the virus. Thereby, their importance and the necessity to tailor their diffusion at large scale for providing services both at a distance and in time has been shown. For these reasons, the European Union advocates the digital transition of health systems for the next 5 years. The main aim of this work is to revisit the telemedicine research projects financed by European Community during the period 2000-2020 with particular respect to the results derived from their application. The analysis showed that some integration of tele-care and tele-health could be obtained with tele-monitoring systems and the implementation of Electronic Personal Record (EPR). Furthermore, telemedicine allows enhancing health care in critical environments, to protect health and life of the most vulnerable patients, and to encourage cross-border dialogue. The criteria of “from distance” and “timely delivered” are granted, but the effectiveness of the overall offered services highly depends on the availability and the quality of the input data. Unfortunately, this remains a relevant problem in the SARS-CoV-2 pandemic
Charged-Particle Multiplicity in Proton-Proton Collisions
This article summarizes and critically reviews measurements of
charged-particle multiplicity distributions and pseudorapidity densities in
p+p(pbar) collisions between sqrt(s) = 23.6 GeV and sqrt(s) = 1.8 TeV. Related
theoretical concepts are briefly introduced. Moments of multiplicity
distributions are presented as a function of sqrt(s). Feynman scaling, KNO
scaling, as well as the description of multiplicity distributions with a single
negative binomial distribution and with combinations of two or more negative
binomial distributions are discussed. Moreover, similarities between the energy
dependence of charged-particle multiplicities in p+p(pbar) and e+e- collisions
are studied. Finally, various predictions for pseudorapidity densities, average
multiplicities in full phase space, and multiplicity distributions of charged
particles in p+p(pbar) collisions at the LHC energies of sqrt(s) = 7 TeV, 10
TeV, and 14 TeV are summarized and compared.Comment: Invited review for Journal of Physics G -- version 2: version after
referee's comment
, K and f Production in Au-Au and pp Collisions at = 200 GeV
Preliminary results on , KK and production using the mixed-event
technique are presented. The measurements are performed at mid-rapidity by the
STAR detector in = 200 GeV Au-Au and pp interactions at RHIC.
The results are compared to different measurements at various energies.Comment: 4 pages, 6 figures. Talk presented at Quark Matter 2002, Nantes,
France, July 18-24, 2002. To appear in the proceedings (Nucl. Phys. A
J/Psi Suppression in Heavy Ion Collisions at the CERN SPS
We reexamine the production of J/Psi and other charmonium states for a
variety of target-projectile choices at the SPS. For this study we use a newly
constructed cascade code LUCIFER II, which yields acceptable descriptions of
both hard and soft processes, specifically Drell-Yan and hidden charm
production, and soft energy loss and meson production, at the SPS. Glauber
calculations of other authors are redone, and compared directly to the cascade
results. The modeling of the charmonium states differs from that of earlier
workers in its unified treatment of the hidden charm meson spectrum, which is
introduced from the outset as a set of coupled states. The result is a
description of the NA38 and NA50 data in terms of a conventional hadronic
picture. The apparently anomalous suppression found in the most massive Pb+Pb
system arises from three sources: destruction in the initial nucleon-nucleon
cascade, use of coupled channels to exploit the larger breakup in the less
bound Chi and Psi' states, and comover interaction in the final low energy
phase.Comment: 36 pages (15 figures
Leading particle effect, inelasticity and the connection between average multiplicities in {\bf } and {\bf } processes
The Regge-Mueller formalism is used to describe the inclusive spectrum of the
proton in collisions. From such a description the energy dependences of
both average inelasticity and leading proton multiplicity are calculated. These
quantities are then used to establish the connection between the average
charged particle multiplicities measured in {\bf } and {\bf } processes. The description obtained for the leading proton cross section
implies that Feynman scaling is strongly violated only at the extreme values of
, that is at the central region () and at the diffraction
region (), while it is approximately observed in the
intermediate region of the spectrum.Comment: 20 pages, 10 figures, to be published in Physical Review
Antiproton Production in 11.5 A GeV/c Au+Pb Nucleus-Nucleus Collisions
We present the first results from the E864 collaboration on the production of
antiprotons in 10% central 11.5 A GeV/c Au+Pb nucleus collisions at the
Brookhaven AGS. We report invariant multiplicities for antiproton production in
the kinematic region 1.4<y<2.2 and 50<p_T<300 MeV/c, and compare our data with
a first collision scaling model and previously published results from the E878
collaboration. The differences between the E864 and E878 antiproton
measurements and the implications for antihyperon production are discussed.Comment: 4 pages, 4 figures; accepted for publication in Physical Review
Letter
Evaluation of the Strong Coupling Constant alpha_s Using the ATLAS Inclusive Jet Cross-Section Data
We perform a determination of the strong coupling constant using the latest
ATLAS inclusive jet cross section data, from proton-proton collisions at
sqrt{s}=7 TeV, and their full information on the bin-to-bin correlations.
Several procedures for combining the statistical information from the different
data inputs are studied and compared. The theoretical prediction is obtained
using NLO QCD, and it also includes non-perturbative corrections. Our
determination uses inputs with transverse momenta between 45 and 600 GeV, the
running of the strong coupling being also tested in this range. Good agreement
is observed when comparing our result with the world average at the Z-boson
scale, as well as with the most recent results from the Tevatron.Comment: 15 pages, 6 figures. Extended discussion of non-perturbative
corrections. Matches version published in EPJ
A Tapestry Of Educational Technology Women Leaders In Higher Education: A Qualitative Study
A qualitative study was used to understand the experiences of 12 women, leaders in Education Technology in higher education. Through interviews, women leaders described their environment as well as personal and behavioral aspects of their work. Findings revealed four threads of descriptive concepts including relationships, leadership, persistence, and advice. Relationships were from workplaces and professional networks. Leadership was defined by vision and teamwork. Persistence was addressed as either values-based or relationship-based. The fourth thread in the findings, advice, was divided into three sub-threads: education, family (both personal and work), and managing emotions. A qualitative approach was used to highlight interview responses to demonstrate the experiences of women leaders in Education Technology in Higher Education
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