14,812 research outputs found
Physics Signatures at CLIC
A set of signatures for physics processes of potential interests for the CLIC
programme at 1 - 5 TeV are discussed. These signatures, that may correspond to
the manifestation of different scenarios of new physics as well to Standard
Model precision tests, are proposed as benchmarks for the optimisation of the
CLIC accelerator parameters and for a first definition of the required detector
response.Comment: 15 pages, 10 figure
Review of Linac-Ring Type Collider Proposals
There are three possibly types of particle colliders schemes: familiar (well
known) ring-ring colliders, less familiar however sufficiently advanced linear
colliders and less familiar and less advanced linac-ring type colliders. The
aim of this paper is two-fold: to present possibly complete list of papers on
linac-ring type collider proposals and to emphasize the role of linac-ring type
machines for future HEP research.Comment: quality of figures is improved, some misprints are correcte
The Heliosphere---Blowing in the Interstellar Wind
Measurements of the velocity of interstellar HeI inside of the heliosphere
have been conducted over the past forty years. These historical data suggest
that the ecliptic longitude of the direction of the interstellar flow has
increased at an average rate of about 0.19 degrees per year over time. Possible
astronomical explanations for these short-term variations in the interstellar
gas entering the heliosphere are presented.Comment: Accepted for the proceedings of Solar Wind 1
Probe of anomalous quartic couplings in the photon-photon collisions
In this paper, we examine the potentials of the processes and at the CLIC with
and TeV to investigate anomalous quartic
couplings by two different CP-violating and CP-conserving effective
Lagrangians. We find confidence level limits on the anomalous coupling
parameters at the three CLIC energies and various integrated luminosities. The
best limits obtained from the process
on the anomalous ,
and couplings
defined by CP-conserving effective Lagrangians are GeV, and GeV, while coupling
determined by CP-violating effective Lagrangians is obtained as GeV. In addition, the best limits derived on
, and
and from the
process are obtained as
GeV, GeV, and GeV, respectively.Comment: 33 pages, 27 figures, 4 tables, version to appear in JHE
Hadronic Cross-sections in two photon Processes at a Future Linear Collider
In this note we address the issue of measurability of the hadronic
cross-sections at a future photon collider as well as for the two-photon
processes at a future high energy linear collider. We extend, to
higher energy, our previous estimates of the accuracy with which the \gamgam\
cross-section needs to be measured, in order to distinguish between different
theoretical models of energy dependence of the total cross-sections. We show
that the necessary precision to discriminate among these models is indeed
possible at future linear colliders in the Photon Collider option. Further we
note that even in the option a measurement of the hadron production
cross-section via \gamgam processes, with an accuracy necessary to allow
discrimination between different theoretical models, should be possible. We
also comment briefly on the implications of these predictions for hadronic
backgrounds at the future TeV energy collider CLIC.Comment: 20 pages, 5 figures, LaTeX. Added an acknowledgemen
Signs of heavy Higgs bosons at CLIC: An road to the Electroweak Phase Transition
We analyse the sensitivity of the proposed Compact Linear Collider (CLIC) to
the existence of beyond the Standard Model (SM) Higgs bosons through their
decays into pairs of massive gauge bosons and SM-like Higgses , considering CLIC centre of mass energies TeV and TeV.
We find that resonant di-Higgs searches at CLIC would allow for up to two
orders of magnitude improvement w.r.t. the sensitivity achievable by HL-LHC in
the mass range . Focusing then
on a real singlet extension of the SM, we explore the prospects of heavy Higgs
searches at CLIC for probing the regions of parameter space yielding a strongly
first order electroweak phase transition that could generate the observed
matter-antimatter asymmetry of the Universe. Our study illustrates the
complementarity between CLIC and other possible future colliders like FCC-ee in
probing singlet extensions of the SM, and shows that high-energy
colliders provide a powerful means to unravel the nature of electroweak
symmetry breaking in the early Universe.Comment: 27 pages, 15 figure
Physics at LHC
The prospects for physics at the LHC are discussed, starting with the
foretaste, preparation (and perhaps scoop) provided by the Tevatron, in
particular, and then continuing through the successive phases of LHC operation.
These include the start-up phase, the early physics runs, the possible search
for new physics in double diffraction, the continuation to nominal LHC running,
and the possible upgrade of the LHC luminosity. Emphasis is placed on the
prospects for Higgs physics and the search for supersymmetry. The progress and
discoveries of the LHC will set the time-scale and agenda for the major future
accelerator projects that will follow it.Comment: 21 pages, 12 figures, Concluding talk at the Physics at LHC
conference, Krakow, July 200
Constraining the Higgs self couplings at colliders
We study the sensitivity to the shape of the Higgs potential of single,
double, and triple Higgs production at future colliders. Physics
beyond the Standard Model is parameterised through the inclusion of
higher-dimensional operators
with , which allows a consistent treatment of independent deviations of
the cubic and quartic self couplings beyond the tree level. We calculate the
effects induced by a modified potential up to one loop in single and double
Higgs production and at the tree level in triple Higgs production, for both
boson associated and boson fusion production mechanisms. We consider two
different scenarios. First, the dimension six operator provides the dominant
contribution (as expected, for instance, in a linear
effective-field-theory(EFT)); we find in this case that the corresponding
Wilson coefficient can be determined at accuracy by just
combining accurate measurements of single Higgs cross sections at 240-250 GeV and double Higgs production in boson fusion at higher
energies. Second, both operators of dimension six and eight can give effects of
similar order, i.e., independent quartic self coupling deviations are present.
Constraints on Wilson coefficients can be best tested by combining measurements
from single, double and triple Higgs production. Given that the sensitivity of
single Higgs production to the dimension eight operator is presently unknown,
we consider double and triple Higgs production and show that combining their
information colliders at higher energies will provide first coarse constraints
on the corresponding Wilson coefficient.Comment: minor changes, version accepted for publication in JHE
Theoretical Introduction to Physics with Linear Colliders
The major open questions in particle physics are summarized, as are the
abilities of linear colliders of different energies to add to the knowledge
obtainable from the LHC in various scenarios for physics beyond the Standard
Model. A TeV linear collider would provide much additional insight into
electroweak symmetry breaking, in particular, and a multi-TeV linear collider
would add even more value in all the scenarios studied, for example in models
with supersymmetry or extra dimensions.Comment: 17 pages LaTeX using sprocl.sty, 9 figures, Invited Talk presented at
the International Conference on Linear Colliders, Paris, April 19-23, 200
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