6 research outputs found
Non-universal gauge boson and the spin correlation of top quark pair production at colliders
In the off-diagonal basis, we discuss the contributions of the non-universal
gauge boson predicted by the topcolor-assisted technicolor () model
to the spin configurations and the spin correlation observable of the top quark
pair production via the process . Our numerical results
show that the production cross sections for the like-spin states, which vanish
in the standard model, can be significantly large as .
With reasonable values of the mass and the coupling parameter
,
exchange can generate large corrections to the spin correlation
observable.Comment: 16 pages, 5 figure
Unparticle Searches Through Compton Scattering
We investigate the effects of unparticles on Compton scattering, e gamma -> e
gamma based on a future e^+e^- linear collider such as the CLIC. For different
polarization configurations, we calculate the lower limits of the unparticle
energy scale Lambda_U for a discovery reach at the center of mass energies
sqrt(s)=0.5 TeV- 3 TeV. It is shown that, especially, for smaller values of the
mass dimension d, (1 <d <1.3), and for high energies and luminosities of the
collider these bounds are very significant. As a stringent limit, we find
Lambda_U>80 TeV for d<1.3 at sqrt(s)=3 TeV, and 1 ab^(-1) integrated luminosity
per year, which is comparable with the limits calculated from other low and
high energy physics implications.Comment: Table 1 and 2 have been combined as Table 1, references updated,
minor typos have been correcte
Dark matter searches at LHC
Besides Standard Model measurements and other Beyond Standard Model studies,
the ATLAS and CMS experiments at the LHC will search for Supersymmetry, one of
the most attractive explanation for dark matter. The SUSY discovery potential
with early data is presented here together with some first results obtained
with 2010 collision data at 7 TeV. Emphasis is placed on measurements and
parameter determination that can be performed to disentangle the possible SUSY
models and SUSY look-alike and the interpretation of a possible positive
supersymmetric signal as an explanation of dark matter.Comment: 15 pages, 14 figures, Invited plenary talk given at DISCRETE 2010:
Symposium On Prospects In The Physics Of Discrete Symmetries, 6-11 Dec 2010,
Rome, Ital
Black Holes at Future Colliders and Beyond: a Topical Review
One of the most dramatic consequences of low-scale (~1 TeV) quantum gravity
in models with large or warped extra dimension(s) is copious production of mini
black holes at future colliders and in ultra-high-energy cosmic ray collisions.
Hawking radiation of these black holes is expected to be constrained mainly to
our three-dimensional world and results in rich phenomenology. In this topical
review we discuss the current status of astrophysical observations of black
holes and selected aspects of mini black hole phenomenology, such as production
at colliders and in cosmic rays, black hole decay properties, Hawking radiation
as a sensitive probe of the dimensionality of extra space, as well as an
exciting possibility of finding new physics in the decays of black holes.Comment: 31 pages, 10 figures To appear in the Journal of Physics
Physics at the CLIC Multi-TeV Linear Collider
This report summarizes a study of the physics potential of the CLIC e+e-
linear collider operating at centre-of-mass energies from 1 TeV to 5 TeV with
luminosity of the order of 10^35 cm^-2 s^-1. First, the CLIC collider complex
is surveyed, with emphasis on aspects related to its physics capabilities,
particularly the luminosity and energy, and also possible polarization,
\gamma\gamma and e-e- collisions. The next CLIC Test facility, CTF3, and its
R&D programme are also reviewed. We then discuss aspects of experimentation at
CLIC, including backgrounds and experimental conditions, and present a
conceptual detector design used in the physics analyses, most of which use the
nominal CLIC centre-of-mass energy of 3 TeV. CLIC contributions to Higgs
physics could include completing the profile of a light Higgs boson by
measuring rare decays and reconstructing the Higgs potential, or discovering
one or more heavy Higgs bosons, or probing CP violation in the Higgs sector.
Turning to physics beyond the Standard Model, CLIC might be able to complete
the supersymmetric spectrum and make more precise measurements of sparticles
detected previously at the LHC or a lower-energy linear e+e- collider:
\gamma\gamma collisions and polarization would be particularly useful for these
tasks. CLIC would also have unique capabilities for probing other possible
extensions of the Standard Model, such as theories with extra dimensions or new
vector resonances, new contact interactions and models with strong WW
scattering at high energies. In all the scenarios we have studied, CLIC would
provide significant fundamental physics information beyond that available from
the LHC and a lower-energy linear e+e- collider, as a result of its unique
combination of high energy and experimental precision.Comment: 226 pages, lots of figures. A version with high resolution figures
can be found at http://cern.ch/d/deroeck/www/clic/clic_report.htm