5,029 research outputs found
Production of Polarized Vector Mesons off Nuclei
Using the light-cone QCD dipole formalism we investigate manifestations of
color transparency (CT) and coherence length (CL) effects in electroproduction
of longitudinally (L) and transversally (T) polarized vector mesons. Motivated
by forthcoming data from the HERMES experiment we predict both the A and Q^2
dependence of the L/T- ratios, for rho^0 mesons produced coherently and
incoherently off nuclei. For an incoherent reaction the CT and CL effects add
up and result in a monotonic A dependence of the L/T-ratio at different values
of Q^2. On the contrary, for a coherent process the contraction of the CL with
Q^2 causes an effect opposite to that of CT and we expect quite a nontrivial A
dependence, especially at Q^2 >> m_V^2.Comment: Revtex 24 pages and 14 figure
Particle Dark Matter Candidates
I give a short overview on some of the favorite particle Cold Dark Matter
candidates today, focusing on those having detectable interactions: the axion,
the KK-photon in Universal Extra Dimensions, the heavy photon in Little Higgs
and the neutralino in Supersymmetry. The neutralino is still the most popular,
and today is available in different flavours: SUGRA, nuSUGRA, sub-GUT, Mirage
mediation, NMSSM, effective MSSM, scenarios with CP violation. Some of these
scenarios are already at the level of present sensitivities for direct DM
searches.Comment: 7 pages, 4 figures, 3 references added. Contribution to the
proceedings of the TAUP 07 conference, Sep. 11-15, Sendai, Japa
UvA-DARE (Digital Academic Repository)
Placebo controlled trial of enteric coated pancreatin microsphere treatment in patients with unresectable cancer of the pancreatic head region Bruno, M.J.; Haverkort, E.B.; Tijssen, J.G.P.; Tytgat, G.N.J.; van Leeuwen, D.J
Aplicação de estratégias da Técnica Alexander para prevenção da ansiedade para alunos do ensino vocacional de piano
A presente dissertação insere-se no âmbito do Mestrado em Ensino da Música –variante de instrumento e classe de conjunto. Incide no estudo da temática da ansiedade na performance, para uma amostra de seis crianças e adolescentes com idades compreendidas entre os seis e os catorze anos, que frequentam a disciplina de Piano.
A ansiedade na performance é um tema bastante complexo. Abordado por autores diversos, é uma problemática que está longe de ser consensual, em torno dos seus mais diversificados aspectos. Assim, também o seu “tratamento” pertence ao campo da incerteza. A Técnica Alexander incide num método que opera sobre o hábito errado, conferindo ao praticante uma nova abordagem na senda do autoconhecimento e autocontrolo. Tem auxiliado, um pouco por todo o mundo, diversos músicos a vencer o medo do palco, tendo inclusivamente salvo carreiras. O objectivo deste estudo passa pela transmissão e trabalho do método de Alexander, de forma a quemelhor se possa compreender e aceitar o fenómeno da ansiedade na performance, a fim de contribuir para uma vida musical mais feliz e proveitosa, por parte dos alunos que estudam o instrumento.Abstract :
This monograph stands for the Master Degree on Musical Teaching –instrument and group music. It incides on the performance anxiety thematic, considering a sample of six children and teenagers, from six to fourteen years old, that attend to Piano course.
Performance anxiety is a truly complex theme. It’s approached by several authors and it’s a far from being concensual problematic, from the most diverse aspects of it’s nature. Alexander’s Technique is a method that works on the wrong habits and it allows it’s user to explore self-knowledge as well as self-control. It’s been effective in helping musicians worldwide to face stage fear and sometimes save their own careers. The objective of thisstudy is to transmit and work on Alexander’s Technique, to help understanding and accepting perfomance anxiety phenomenon, so to contribute to a happy and profitable musical life of the piano students
Construction and commissioning of a technological prototype of a high-granularity semi-digital hadronic calorimeter
A large prototype of 1.3m3 was designed and built as a demonstrator of the
semi-digital hadronic calorimeter (SDHCAL) concept proposed for the future ILC
experiments. The prototype is a sampling hadronic calorimeter of 48 units. Each
unit is built of an active layer made of 1m2 Glass Resistive Plate
Chamber(GRPC) detector placed inside a cassette whose walls are made of
stainless steel. The cassette contains also the electronics used to read out
the GRPC detector. The lateral granularity of the active layer is provided by
the electronics pick-up pads of 1cm2 each. The cassettes are inserted into a
self-supporting mechanical structure built also of stainless steel plates
which, with the cassettes walls, play the role of the absorber. The prototype
was designed to be very compact and important efforts were made to minimize the
number of services cables to optimize the efficiency of the Particle Flow
Algorithm techniques to be used in the future ILC experiments. The different
components of the SDHCAL prototype were studied individually and strict
criteria were applied for the final selection of these components. Basic
calibration procedures were performed after the prototype assembling. The
prototype is the first of a series of new-generation detectors equipped with a
power-pulsing mode intended to reduce the power consumption of this highly
granular detector. A dedicated acquisition system was developed to deal with
the output of more than 440000 electronics channels in both trigger and
triggerless modes. After its completion in 2011, the prototype was commissioned
using cosmic rays and particles beams at CERN.Comment: 49 pages, 41 figure
Vacuum Structure and the Axion Walls in Gluodynamics and QCD with Light Quarks
Large N gluodynamics was shown to have a set of metastable vacua with the
gluonic domain walls interpolating between them. The walls may separate the
genuine vacuum from an excited one, or two excited vacua which are unstable at
finite N (here N is the number of colors). One may attempt to stabilize them by
switching on the axion field. We study how the light quarks and the axion
affect the structure of the domain walls. In pure gluodynamics (with the axion
field) the axion walls acquire a very hard gluonic core. Thus, we deal with a
wall "sandwich" which is stable at finite N. In the case of the minimal axion,
the wall "sandwich" is in fact a "2-pi" wall, i.e., the corresponding field
configuration interpolates between identical hadronic vacua. The same
properties hold in QCD with three light quarks and very large number of colors.
However, in the realistic case of three-color QCD the phase corresponding to
the axion field profile in the axion wall is screened by a dynamical phase
associated with the eta-prime, so that the gluon component of the wall is not
excited. We propose a toy Lagrangian which models these properties and allows
one to get exact solutions for the domain walls.Comment: 22 pages Latex, no figure
Construction and Performance of Large-Area Triple-GEM Prototypes for Future Upgrades of the CMS Forward Muon System
At present, part of the forward RPC muon system of the CMS detector at the
CERN LHC remains uninstrumented in the high-\eta region. An international
collaboration is investigating the possibility of covering the 1.6 < |\eta| <
2.4 region of the muon endcaps with large-area triple-GEM detectors. Given
their good spatial resolution, high rate capability, and radiation hardness,
these micro-pattern gas detectors are an appealing option for simultaneously
enhancing muon tracking and triggering capabilities in a future upgrade of the
CMS detector. A general overview of this feasibility study will be presented.
The design and construction of small (10\times10 cm2) and full-size trapezoidal
(1\times0.5 m2) triple-GEM prototypes will be described. During detector
assembly, different techniques for stretching the GEM foils were tested.
Results from measurements with x-rays and from test beam campaigns at the CERN
SPS will be shown for the small and large prototypes. Preliminary simulation
studies on the expected muon reconstruction and trigger performances of this
proposed upgraded muon system will be reported.Comment: 7 pages, 25 figures, submitted for publication in conference record
of the 2011 IEEE Nuclear Science Symposium, Valencia, Spai
Performance of Glass Resistive Plate Chambers for a high granularity semi-digital calorimeter
A new design of highly granular hadronic calorimeter using Glass Resistive
Plate Chambers (GRPCs) with embedded electronics has been proposed for the
future International Linear Collider (ILC) experiments. It features a 2-bit
threshold semi-digital read-out. Several GRPC prototypes with their electronics
have been successfully built and tested in pion beams. The design of these
detectors is presented along with the test results on efficiency, pad
multiplicity, stability and reproducibility.Comment: 16 pages, 15 figure
An overview of the design, construction and performance of large area triple-GEM prototypes for future upgrades of the CMS forward muon system
GEM detectors are used in high energy physics experiments given their good spatial resolution, high rate capability and radiation hardness. An international collaboration is investigating the possibility of covering the 1.6 < vertical bar eta vertical bar < 2.4 region of the CMS muon endcaps with large-area triple-GEM detectors. The CMS high-eta area is actually not fully instrumented, only Cathode Strip Chamber (CSC) are installed. The vacant area presents an opportunity for a detector technology able to to cope with the harsh radiation environment; these micropattern gas detectors are an appealing option to simultaneously enhance muon tracking and triggering capabilities in a future upgrade of the CMS detector. A general overview of this feasibility study is presented. Design and construction of small (10cm x 10cm) and full-size trapezoidal (1m x 0.5m) triple-GEM prototypes is described. Results from measurements with x-rays and from test beam campaigns at the CERN SPS is shown for the small and large prototypes. Preliminary simulation studies on the expected muon reconstruction and trigger performances of this proposed upgraded muon system are reported
The first determination of Generalized Polarizabilities of the proton by a Virtual Compton Scattering experiment
Absolute differential cross sections for the reaction (e+p -> e+p+gamma) have
been measured at a four-momentum transfer with virtuality Q^2=0.33 GeV^2 and
polarization \epsilon = 0.62 in the range 33.6 to 111.5 MeV/c for the momentum
of the outgoing photon in the photon-proton center of mass frame. The
experiment has been performed with the high resolution spectrometers at the
Mainz Microtron MAMI. From the photon angular distributions, two structure
functions which are a linear combination of the generalized polarizabilities
have been determined for the first time.Comment: 4 pages, 3 figure
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