776,999 research outputs found
Detecting an invisible Higgs boson at Fermilab Tevatron and CERN LHC
In this paper, we study the observability of an invisible Higgs boson at
Fermilab Tevatron and CERN LHC through the production channel q \bar{q} \to Z
H \to \ell^+\ell^-+ \ptmiss , where \ptmiss is reconstructed from the
with or . A new strategy is proposed to eliminate
the largest irreducible background, namely . This strategy utilizes the precise measurements of . For GeV and
with luminosity at Tevatron, a observation of the
invisible Higgs boson is possible. For GeV with only luminosity at LHC, a discovery signal over can be achieved.Comment: 4 Revtex pages including 2 figure
Axion Searches
The strong CP problem and its resolution through the existence of an axion
are briefly reviewed. The constraints on the axion from accelerator searches,
from the evolution of red giants and from supernova SN1987a combine to require
eV, where is the axion mass. On the other hand,
the constraint that axions do not overclose the universe implies m_a \gtwid
10^{-6} eV. If eV, axions contribute significantly to the
cosmological energy density in the form of cold dark matter. Dark matter axions
can be detected by resonant conversion to microwave photons in a cavity
permeated by a static magnetic field and tuned to the axion mass. Experiments
using this effect are described, as well as several other types of axion
searches.Comment: 12 pages, 2 figures, based on talks at the TAUP99 Conference (Sept.
6-10, 1999, Paris, France) and at Adrianfest (Sept. 24-25, 1999, Rochester,
NY
Higgs Searches
We present the status and prospects of Higgs searches at the Tevatron and the
LHC. Results from the Tevatron are using up to 5/fb of data collected with the
CDF and D0 detectors. The major contributing processes include associated
production with vector bosons and gluon fusion. Improvements across the full
mass range resulting from the larger data sets, improved analyses techniques
and increased signal acceptance are discussed. Recent results exclude the SM
Higgs boson in a mass range of 160 < mH < 170 GeV. Searches for the neutral
MSSM Higgs boson in the region 90 < mA < 200 GeV exclude tanB values down to 30
for several benchmark scenarios.Comment: 6 pages, 13 figures, to be submitted in "XXIX Physics in Collision,
Proceedings of the International Symposium in Kobe, Japan, August 30 -
September 2, 2009
New particle searches
This review presents recent results on new particle searches achieved at
Tevatron, Hera and LEP. After a brief outline of the searches on exotic
particles, results on supersymmetric particles and Higgs bosons are detailed.
Near future prospects are also given.Comment: 25 pages, 11 postscript figures, typo corrections. To appear in
Proceedings of XIX Lepton-Photon Symposium, Stanford, August 199
Searches at HERA
Searches for physics beyond the Standard Model have been performed in
high-energy collisions at HERA. No significant deviation from the
Standard Model has been observed while searching for contact interactions,
extra dimensions, leptoquarks, R-parity violating squarks and excited fermions.
Exclusion limits have been inferred which extend or complement bounds from
other colliders. The H1 collaboration has observed a puzzling excess of events
with an high isolated lepton and missing transverse momentum, and
interpretation as flavour changing neutral currents has been explored.Comment: 7 pages, 6 figures, contribution to the Lake Louise Winter Institut
RooStats for Searches
The RooStats toolkit, which is distributed with the ROOT software package,
provides a large collection of software tools that implement statistical
methods commonly used by the High Energy Physics community. The toolkit is
based on RooFit, a high-level data analysis modeling package that implements
various methods of statistical data analysis. RooStats enforces a clear mapping
of statistical concepts to C++ classes and methods and emphasizes the ability
to easily combine analyses within and across experiments. We present an
overview of the RooStats toolkit, describe some of the methods used for
hypothesis testing and estimation of confidence intervals and finally discuss
some of the latest developments.Comment: Contributed to "PHYSTAT 2011 Workshop on Statistical Issues Related
to Discovery Claims in Search Experiments and Unfolding
- …