3,207 research outputs found
LHC/ILC Interplay in SUSY Searches
Combined analyses at the Large Hadron Collider and at the International
Linear Collider are important to reveal precisely the new physics model as, for
instance, supersymmetry. Examples are presented where ILC results as input for
LHC analyses could be crucial for the identification of signals as well as of
the underlying model. The synergy of both colliders leads also to rather
accurate SUSY parameter determination and powerful mass constraints even if the
scalar particles have masses in the multi-TeV range.Comment: 5 pages, contribution to the proceedings of EPS0
Strong field effects on physics processes at the Interaction Point of future linear colliders
Future lepton colliders will be precision machines whose physics program
includes close study of the Higgs sector and searches for new physics via
polarised beams. The luminosity requirements of such machines entail very
intense lepton bunches at the interaction point with associated strong
electromagnetic fields. These strong fields not only lead to obvious phenomena
such as beamstrahlung, but also potentially affect every particle physics
process via virtual exchange with the bunch fields. For precision studies,
strong field effects have to be understood to the sub-percent level. Strong
external field effects can be taken into account exactly via the Furry Picture
or, in certain limits, via the Quasi-classical Operator method . Significant
theoretical development is in progress and here we outline the current state of
play.Comment: 6 pages, ICHEP 2012 Proceeding
Probing the top-quark width through ratios of resonance contributions of
We exploit offshell regions in the process
to gain access to the top-quark width. Working at next-to-leading order in QCD
we show that carefully selected ratios of offshell regions to onshell regions
in the reconstructed top and antitop invariant mass spectra are,
\emph{independently} of the coupling , sensitive to the top-quark
width. We explore this approach for different centre of mass energies and
initial-state beam polarisations at colliders and briefly comment on
the applicability of this method for a measurement of the top-quark width at
the LHC.Comment: 31 pages, 10 figures, 2 table
New Ideas on SUSY Searches at Future Linear Colliders
Several results obtained within the SUSY group of the ECFA/DESY linear
collider study are presented: (i) a possibility to determine tan beta and the
trilinear couplings A_f via polarisation in sfermion decays, (ii) the impact of
complex MSSM parameters on the third generation sfermion decays, (iii)
determination of CP violation in the complex MSSM via T-odd asymmetries in
neutralino production and decay, and (iv) an analysis of the chargino and
neutralino mass parameters at one-loop level.Comment: 3 pages, LaTeX, 5 eps figures; talk presented by S. Hesselbach at the
International Europhysics Conference on High Energy Physics (HEP 2003), 17-23
July 2003, Aachen, German
Identifying the NMSSM by the interplay of LHC and ILC
The interplay between the LHC and the International Linear Collider
(ILC) with GeV might be crucial for the discrimination between
the minimal and next-to-minimal supersymmetric standard model. We present an
NMSSM scenario, where the light neutralinos have a significant singlino
component, that cannot be distinguished from the MSSM by cross sections and
mass measurements. Mass and mixing state predictions for the heavier
neutralinos from the ILC analysis at different energy stages and comparison
with observation at the LHC, lead to clear identification of the particle
character and identify the underlying supersymmetric model.Comment: 8 pages, 2 eps figures, revtex4 style Contribution to the `2005
International Linear Collider Workshop - Stanford, U.S.A.
Photon collimator system for the ILC Positron Source
High energy e+e- linear colliders are the next large scale project in
particle physics. They need intense sources to achieve the required luminosity.
In particular, the positron source must provide about 10E+14 positrons per
second. The positron source for the International Linear Collider (ILC) is
based on a helical undulator passed by the electron beam to create an intense
circularly polarized photon beam. With these photons a longitudinally polarized
positron beam is generated; the degree of polarization can be enhanced by
collimating the photon beam. However, the high photon beam intensity causes
huge thermal load in the collimator material. In this paper the thermal load in
the photon collimator is discussed and a flexible design solution is presented.Comment: 22 pages, 19 figures, 8 tables, cross-reference to table 4 fixe
Market and Welfare Effects of Mandatory Country-of-Origin Labeling in the US Specialty Crops Sector
This study provides a new framework of analysis of the market and welfare effects of mandatory country of origin labeling (MCOOL) for fruits and vegetables that accounts for heterogeneous consumer preferences for domestic products, differences in producer agronomic characteristics, and retailer market power when buying and selling these products. The market and welfare effects of MCOOL are shown to be case-specific and dependent on the labeling costs at the farm and retail levels, the strength of consumer preference for domestic products, the market power of retailers, the marketing margin along the supply chain, and the relative costs of imported and domestic products. Simulation results for the US markets of apples and tomatoes indicate that for the regulation to increase total economic welfare in these markets, the consumer demand after MCOOL would need to increase by 2.6% to 7.0% for domestic apples and by 8.2% to 22.4% for domestic tomatoes, depending on the market power of retailers and the size of the labeling costs.Crop Production/Industries, International Relations/Trade,
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