4,390 research outputs found
Selected design issues of a dedicated facility for generic QCD studies
QCD, even if presently out of fashion, deserves a dedicated, generic research
program providing new challenges for the theory and aiming at understanding
hadronic matter and vacuum in terms of quark and gluon degrees of freedom. Such
a research program needs a dedicated facility to re-address basic questions
which remain unanswered and to open new vistas.Comment: 5 pages, 4 figures, talk at Workshop on the Spin Structure of the
Proton and Polarized Collider Physic
Summary of the Experimental part of the XXXIVth Rencontre de Moriond
I summarise the experimental results presented during the hadronic session of
the XXXIVth Rencontre de Moriond.Comment: Moriond summary talk, Les Arcs, March 20-27, 1999, 15 page
Ascertaining the origin of the excess events at the LHC by a change of beam energy
A higher than predicted rate of two leptons plus missing transverse energy
events, reported at the summer HEP conferences, can originate from a decay of
the Higgs boson into a pair, a misjudgement of the rate of SM
background processes or a statistical fluctuation. In this paper we discuss a
way to resolve this three-fold ambiguity.Comment: 10 pages, 4 figures, version 2: Fig. 1 removed to comply with the
ATLAS policy rule
Challenges for precision measurements at the LHC
Challenges for precision measurements at the LHC are discussed and a proposal
how to move forward to overcome the LHC-specific precision brick-walls is
presented.Comment: 4 pages, Presented at the ICISE Inaugural Conference "Windows on the
Universe" - Quy Nhon, Vietnam, August 11-17, 201
The Gamma Factory proposal for CERN
This year, 2015, marks the centenary of the publication of Einsteins Theory
of General Relativity and it has been named the International Year of Light and
light-based technologies by the UN General Assembly. It is thus timely to
discuss the possibility of broadening the present CERN research program by
including a new component based on a novel concept of the light source which
could pave a way towards a multipurpose Gamma Factory. The proposed light
source could be realized at CERN by using the infrastructure of the existing
accelerators. It could push the intensity limits of the presently operating
light-sources by at least 7 orders of magnitude, reaching the flux of the order
of 10^17 photons/s, in the particularly interesting gamma-ray energy domain of
1 < Ephoton < 400 MeV. This domain is out of reach for the FEL-based light
sources. The energy-tuned, quasi-monochromatic gamma beams, together with the
gamma-beam-driven, high intensity secondary beams of polarized positrons,
polarized muons, neutrons and radioactive ions would constitute the basic
research tools of the proposed Gamma Factory. The Gamma Factory could open new
research opportunities in a vast domain of uncharted fundamental physics and
industrial application territories. It could strengthen the leading role of
CERN in the high energy frontier research territory by providing the
unprecedented-brilliance secondary beams of polarized muons for the
TeV-energy-scale muon collider and the polarized- muon-beam based neutrino
factory.Comment: An Executive Summary of the Gamma Factory proposal addressed to the
CERN management. 6 page
Citizen Science in Disaster and Conflict Resilience
*Background/Question/Methods*

Within the disaster and conflict response communities, concern about lack of effectiveness of outside responses has led to a debate about the role of local people in developing the capacity to prepare for a crisis and to respond after calamity has struck. Pelling (2007) points out the potential for participatory disaster risk assessment to build local capacity and for generating knowledge that, along with more expert-driven data collection, is used to identify and reduce the risk of disaster. Similarly, Weinstein and Tidball (2007) and Tidball et al. (2008) present an alternative model for post-crisis intervention based on local assets, including ongoing attempts of communities to manage their natural resources. For example, these authors suggest that civic ecology (CE) practices, including community forestry, watershed enhancement, community agriculture and gardening, and other participatory environmental restoration initiatives that emerge from the actions of local residents (Tidball and Krasny 2007), should be examined and perhaps leveraged by outsiders for their ability to mitigate post-crisis situations. The question is, how might CE relate to citizen science in applications post-disaster or conflict?

*Results/Conclusions*

CE practices emerge through the actions of people wanting to manage a local resource, and integrate both learning through small-scale experimentation and observations (adaptive management) and collaborative or participatory processes (co-management). They can be considered as an emergent form of adaptive co-management (Ruitenbeek and Cartier 2001; Armitage, Plummer et al. 2009). The local knowledge of individuals who initiate the practices is critical, although often linkages are made with scientists from universities, government, and non-profit organizations, so multiple forms of knowledge are incorporated into the stewardship activities. This learning shortens feedback times between management actions, such as participatory approaches for planting trees, and seeing the impact of tree planting on local ecological and social systems. CE practices embody attributes that may foster resilience both prior to and post-crisis, including multiple forms of knowledge and governance, self-organization, adaptive learning, shorter feedbacks, and ecosystem services (Folke, S. Carpenter et al. 2002; Walker and Salt 2006). We demonstrate that similar to CE, citizen science could build capacity to mitigate disaster and conflict through shortening feedbacks and through making available multiple forms of knowledge and data collection. Further, given the need for asset-based and participatory interventions post-crisis, and the paucity of existing mechanisms that address this need (Weinstein and Tidball 2007), we examine citizen science and its potential to become part of a tool kit of participatory responses that engage citizens in meaningful activity post-conflict
Charge asymmetries of lepton transverse momenta in Drell-Yan processes at the LHC
Charged lepton transverse momenta in the Drell-Yan processes play an
important role at the LHC in precision measurements of the Standard Model
parameters, such as the W-boson mass and width, their charge asymmetries and
sin^2(theta_W). Therefore, their distributions should be described as accurate
as possible by the Monte Carlo event generators. In this paper we discuss the
problem of matching the hard-process kinematics of the Monte Carlo generator
WINHAC with the parton-shower kinematics of the PYTHIA 6.4 generator while
interfacing these two programs. We show that improper assignment of the quark
and antiquark effective momenta in the LO matrix element computations may
affect considerably the predicted lepton transverse momenta and even completely
reverse their charge asymmetries at the LHC. We propose two matching schemes in
which the NLO QCD distributions of the leptonic kinematical variables can be
well reproduced by the LO WINHAC generator.Comment: 18 pages, 8 figure
The LHC excess of four-lepton events interpreted as Higgs-boson signal: background from Double Drell--Yan process?
We construct a simple model of the Double Drell--Yan Process (DDYP) for
proton--proton collisions and investigate its possible contribution to the
background for the Higgs-boson searches at the LHC. We demonstrate that under
the assumption of the predominance of short range, fm,
transverse-plane correlations of quark--antiquark pairs within the proton this
contribution becomes important and may even explain the observed excess of the
four-lepton events at the LHC -- the events interpreted as originating from the
Higgs-boson decays: and .Comment: 19 pages, 4 figures, Version 2 matches the published versio
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