7,467 research outputs found
Delta G(x) from high p_t hadrons in DIS at a polarised HERA
We investigate the possibility to identify photon-gluon fusion (PGF) events
in polarised deep inelastic ep scattering, assuming the kinematics of the HERA
collider, by a pair of charged high p_t particles. In a Monte Carlo study we
find possible selection criteria and show the expected measurable asymmetries.
We discuss the sensitivity to and compare the result to the one
obtained using di-jets to tag PGF events.Comment: 8 pages, 5 figures, Contributed paper to the Proceedings of the
Workshop on Physics at HERA with Polarized Protons and Electron
The polarised gluon density Delta G(x) from di-jet events at high energy ep-colliders
We present the potential to determine the polarised gluon density from
boson-gluon fusion processes with di-jet events at future high energy
ep-colliders. These include HERA at DESY operated with polarised electrons and
protons, polarised protons from HERA colliding on polarised electrons from a
future linear collider, and polarised protons from RHIC at BNL colliding on
electrons from a future electron accelerator.Comment: 5 pages, 7 figures, Invited talk presented at the ``International
Workshop on the Spin Structure of the Proton and Polarized Collider
Physics'', ECT, Trento, Italy, July 23-28, 200
The polarised gluon density from di-jet events in DIS at a polarised HERA
We present a possible direct measurement of the polarised gluon density
in LO from di-jet production in polarised deep inelastic ep
scattering, assuming the kinematics of the HERA collider. We show the
sensitivity to the x-dependence of and to the first moment in the range , assuming the electron and proton
beam of HERA being polarised to 70% and an integrated luminosity of at least
200 pb. We include in our study hadronisation and higher order effects,
as well as realistic detector smearing and acceptance. We find that the
statistical and systematic uncertainties are small enough to distinguish
between different parametrizations for , which all are in
accordance with present data. We stress that at HERA an x-range could be
measured, that is not accessible to any other present or proposed experiment.Comment: 15 pages, 9 figures, Contributed paper to the Proceedings of the
Workshop on Physics at HERA with Polarized Protons and Electron
Predictions for the total cross-section in the TeV region: an update
In this talk we present an update of model predictions for the total cross-section in the TeV region. The update includes preliminary
results for cross-sections using the Bloch-Nordsieck model for
the overlap function of the partons in the transverse space, use of the CJLK
parametrisation of the photonic parton densities that has recently become
available and extension to the higher energies relevant to the
planned CLIC collider.Comment: Talk presented by A. De Roeck at the International Linear Collider
Workshop, Jeju Island, Aug. 26-30,2002. To appear in the proceedings. 10
pages, LaTeX file, requires A4.sty, four figure
Total Cross-Sections : Cross-Talk between HERA, LHC and LC
We discuss the need to compare total cross-section measurements at LHC and
HERA with each other and with available models in order to obtain a more
precise prediction of the total hadronic cross-section at the future Linear
Collider, thus leading to a better estimate of the hadronic background.Comment: 5 pages, three figures, Talk presented by G. Pancheri at the
International Linear Collider Workshop, Paris, April, 200
Implications of initial LHC searches for supersymmetry
13 pĂĄginas, 7 figuras, 1 tabla.-- El Pdf del artĂculo es la versiĂłn pre-print: arXiv:1102.4585v1.-- et al.The CMS and ATLAS Collaborations have recently published the results of initial direct LHC searches for supersymmetry analyzing âŒ35/pb of data taken at 7 TeV in the centre of mass. We incorporate these results into a frequentist analysis of the probable ranges of parameters of simple versions of the minimal supersymmetric extension of the Standard Model (MSSM), namely the constrained MSSM (CMSSM), a model with common non-universal Higgs masses (NUHM1), the very constrained MSSM (VCMSSM) and minimal supergravity (mSUGRA). We present updated predictions for the gluino mass, m[(g)\tilde]mg, the light-Higgs boson mass, M h , BR(B s âÎŒ + ÎŒ â) and the spin-independent dark matter scattering cross section, sSIppSI. The CMS and ATLAS data make inroads into the CMSSM, NUHM1 and VCMSSM (but not mSUGRA) parameter spaces, thereby strengthening previous lower limits on sparticle masses and upper limits on sSIppSI in the CMSSM and VCMSSM. The favoured ranges of BR(B s âÎŒ + ÎŒ â) in the CMSSM, VCMSSM and mSUGRA are close to the Standard Model, but considerably larger values of BR(B s âÎŒ + ÎŒ â) are possible in the NUHM1. Applying the CMS and ATLAS constraints improves the consistency of the model predictions for M h with the LEP exclusion limits.This work was supported in part by the European
Communityâs Marie-Curie Research Training Network under
contracts MRTN-CT-2006-035505 âTools and Precision Calculations
for Physics Discoveries at Collidersâ and MRTN-CT-2006-035482
âFLAVIAnetâ, and by the Spanish MEC and FEDER under grant
FPA2005-01678. The work of S.H. was supported in part by CICYT
(grant FPA 2007â66387 and FPA 2010â22163-C02-01), and the work
of K.A.O. was supported in part by DOE grant DEâFG02â94ERâ
40823 at the University of Minnesota. K.A.O. also thanks SLAC (supported
by the DOE under contract number DE-AC02-76SF00515).Peer reviewe
SASICE: Safety and sustainability in civil engineering
The performance of the built environment and the construction sector are of major importance in Europeâs long term goals of sustainable development in a changing climate. At the same time, the quality of life of all European citizens needs to be improved and the safety of the built environment with respect to man-made and natural hazards, such as flooding and earthquakes, needs to be ensured. Education has a central role to play in the transformation of a construction sector required to meet increasing demands with regard to safety and sustainability. In this work, the SASICE project is presented. The aim of this project is to promote the integration of safety and sustainability in civil engineering education. The project is organised in the context of the Lifelong Learning Programme, funded by the European Community. The coordinator organisation is the University of Bologna. Nine partner universities from different countries are involved in this transnational project. The universities participating to the project constitute a network of high level competences in the civil engineering area, with several opportunities to improve lifelong learning adopting different media: joint curricula, teaching modules and professor and student exchanges. As a response to the challenge regarding new educational methods in sustainable engineering, teaching modules are developed in 4 thematic areas: (1) Safety in construction, (2) Risk induced by Natural Hazards Assessment, (3) Sustainability in construction, and (4) Sustainability at the territorial level. The development of the teaching modules is based on an extensive analysis of the need for highly qualified education on Safety and Sustainability involving all relevant stakeholders (European and national authorities, companies, research institutes, professional organizations, and universities).The main target is enabling students to introduce these advanced topics in their study plans and curricula and reach, at the end of their studies, a specific skill and expertise in safety and sustainability in Civil Engineering. With our natural resources fading away and our infrastructure in dire need of repair, new trends and challenges in civil engineering education in the concept of âSustainable Developmentâ are needed to be adressed.<br/
Derivation of some translation-invariant Lindblad equations for a quantum Brownian particle
We study the dynamics of a Brownian quantum particle hopping on an infinite
lattice with a spin degree of freedom. This particle is coupled to free boson
gases via a translation-invariant Hamiltonian which is linear in the creation
and annihilation operators of the bosons. We derive the time evolution of the
reduced density matrix of the particle in the van Hove limit in which we also
rescale the hopping rate. This corresponds to a situation in which both the
system-bath interactions and the hopping between neighboring sites are small
and they are effective on the same time scale. The reduced evolution is given
by a translation-invariant Lindblad master equation which is derived
explicitly.Comment: 28 pages, 4 figures, minor revisio
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