297 research outputs found
Alternative subtraction scheme using Nagy Soper dipoles
We present an alternative subtraction scheme for the treatment of infrared
divergences in NLO QCD calculations. In this scheme, the number of
transformations is greatly reduced with respect to the standard subtraction
scheme by Catani and Seymour. We discuss the general setup of the scheme as
well as first applications to NLO processes at hadron and lepton colliders.Comment: 6 pages, 1 figure, presented at RADCOR 0
NLO Simulations of Chargino Production at the ILC
We present an extension of the Monte Carlo Event Generator Whizard which
includes chargino production at the ILC at NLO. We present two ways of adding
photonic contributions. We present results for cross sections and event
generation.Comment: 4 pages, to appear in Proceedings of SUSY06, the 14th International
Conference on Supersymmetry and the Unification of Fundamental Interactions,
UC Irvine, California, 12-17 June 200
Nagy-Soper subtraction scheme for multiparton final states
In this work, we present the extension of an alternative subtraction scheme
for next-to-leading order QCD calculations to the case of an arbitrary number
of massless final-state partons. The scheme is based on the splitting kernels
of an improved parton shower and comes with a reduced number of final state
momentum mappings. While a previous publication including the setup of the
scheme has been restricted to cases with maximally two massless partons in the
final state, we here provide the final state real emission and integrated
subtraction terms for processes with any number of massless partons. We apply
our scheme to three jet production at lepton colliders at next-to-leading order
and present results for the differential C parameter distribution.Comment: 45 pages, 5 figures v2: several references added; v3: title changed,
references and a discussion of further scaling improvement added. Corresponds
to published journal versio
(N)LO Simulation of Chargino Production and Decay
We consider NLO chargino production and decays at the ILC. For this, we
present an NLO extension of the Monte Carlo Event Generator Whizard including
the NLO production. For photonic corrections, we use both a fixed order and a
resummation approach. The latter method evades the problem of negative event
weights and automatically includes leading higher order corrections. We present
results for cross sections and event generation for both methods. As a first
step towards a full NLO Monte Carlo, we consider a LO implementation of the
chargino production and subsequent leptonic decay and investigate the precision
of the sneutrino mass determination by means of lepton energy distributions in
chargino decays. The SM and SUSY backgrounds are included in our study using
full matrix elements as well as smearing effects from ISR and beamstrahlung.
Without using energy distribution fits, the sneutrino mass can be determined
with an error in the percent regime.Comment: 10 pages, 6 figures; Talk presented at the Cracow Epiphany Conference
on LHC Physics 2008; Submitted to Acta Physica Polonica
"A non-person to the rest of the world": experiences of social isolation amongst severely impaired people with multiple sclerosis.
PURPOSE: To gain insight into the experiences of, and potential solutions to, social isolation amongst severely impaired people with multiple sclerosis. METHODS: A phenomenological research approach using face-to-face, in-depth semi-structured, audio-recorded interviews. Data were transcribed and analyzed thematically. RESULTS: Sixteen severely impaired people with multiple sclerosis were interviewed (Expanded Disability Status Scale >6.5); aged 38-72 years, nine female, time since diagnosis ranged 3-30 years). Four key themes were generated in line with the study objectives, each with further sub-themes. The themes were (1) Definitions of isolation (2) Causes of isolation (3) Impact of isolation, and (4) Potential eases of isolation. CONCLUSIONS: Data portrayed social isolation as complex and multi-factorial in its definitions, its causes, and its impact. Isolation is not just about being lonely or left on one's own, but represents a spiral of impacts. Physical deterioration can lead to reduced choice and control regarding access to, and interaction with others and society, affecting personal identity. Sometimes this leads to further self-isolation. Personalised psychosocial support, with improved ease of access, focused on helping people with severe multiple sclerosis regain a sense of self and their place in the world may ease social isolation. Implications for rehabilitation People with severe multiple sclerosis can experience a sense of powerlessness, a lack of choice and control over daily life, leading to changes in self-identity and social isolation. Peoples' experiences are very personal, and any approach to help deal with social isolation needs to be based in considering how to think positively about how life can be lived and how to make that work. Multiple sclerosis support groups should not be assumed to alleviate feelings of social isolation. Interventions should focus on personalized psychosocial input aimed at helping the person with multiple sclerosis regain a sense of self and their place in the world
Sqrt{shat}_{min} resurrected
We discuss the use of the variable sqrt{shat}_{min}, which has been proposed
in order to measure the hard scale of a multi parton final state event using
inclusive quantities only, on a SUSY data sample for a 14 TeV LHC. In its
original version, where this variable was proposed on calorimeter level, the
direct correlation to the hard scattering scale does not survive when effects
from soft physics are taken into account. We here show that when using
reconstructed objects instead of calorimeter energy and momenta as input, we
manage to actually recover this correlation for the parameter point considered
here. We furthermore discuss the effect of including W + jets and t tbar+jets
background in our analysis and the use of sqrt{shat}_{min} for the suppression
of SM induced background in new physics searches.Comment: 23 pages, 9 figures; v2: 1 figure, several subsections and references
as well as new author affiliation added. Corresponds to published versio
ИССЛЕДОВАНИЕ УСЛОВИЙ ЗАЛЕГАНИЯ, СОСТАВА И СВОЙСТВ УРАНОВЫХ МЕСТОРОЖДЕНИЙ МОНГОЛИИ
Представлены результаты промышленных и лабораторных исследований условий залегания, состава и свойств урановых месторождений Монголии. Выполнены механические, геофизические и геохимические исследования вещественных и радиологических свойств урановых ру
New Physics at the LHC. A Les Houches Report: Physics at TeV Colliders 2009 - New Physics Working Group
We present a collection of signatures for physics beyond the standard model
that need to be explored at the LHC. First, are presented various tools
developed to measure new particle masses in scenarios where all decays include
an unobservable particle. Second, various aspects of supersymmetric models are
discussed. Third, some signatures of models of strong electroweak symmetry are
discussed. In the fourth part, a special attention is devoted to high mass
resonances, as the ones appearing in models with warped extra dimensions.
Finally, prospects for models with a hidden sector/valley are presented. Our
report, which includes brief experimental and theoretical reviews as well as
original results, summarizes the activities of the "New Physics" working group
for the "Physics at TeV Colliders" workshop (Les Houches, France, 8-26 June,
2009).Comment: 189 page
- …