7,161 research outputs found
Higgs Sector of Non-minimal Supersymmetric Models at Future Hadron Colliders
We investigate the potential of current and planned hadron colliders
operating at the TeV scale in disentangling the structure of the Higgs sector
of non-minimal Supersymmetric extensions of the Standard Model with an extra
gauge singlet. We assume universality of the soft Supersymmetry breaking terms
at the GUT scale as well as a CP-even Higgs boson with mass around 115 GeV, as
suggested by LEP. We find that mixing angles between the doublet and singlet
Higgs states are always small. However, concrete prospects exist at both the
Tevatron (Run II) and the Large Hadron Collider of detecting at least one
neutral Higgs state with a dominant singlet component, in addition to those
available from a doublet Higgs sector which is similar to the one of the
Minimal Supersymmetric Standard Model.Comment: 4 pages, 2 figures, latex, contribution to the APS/DPF/DPB Summer
Study on the `Future of Particle Physics (Snowmass 2001)', Snowmass,
Colorado, 30 June - 21 July 200
A chemical evolution model for galaxy clusters
We develop a toy-model for the chemical evolution of the intracluster medium,
polluted by the galactic winds from elliptical galaxies. The model follows the
"galaxy formation history" of cluster galaxies, constrained by the observed
luminosity function.Comment: 6 pages, 10 figures, to appear in the Proceedings of the Workshop
"Chemical Enrichment of Intracluster and Intergalactic Medium", Vulcano,
Italy, 14-18 May 2001, ASP Conference Serie
Protocolos de avaliação da qualidade quĂmica e fĂsica de tomate.
bitstream/item/103087/1/cot-32.pd
Hunting for neutral, long-lived exotica at the LHC using a missing transverse energy signature
Searches at the Large Hadron Collider (LHC) for neutral, long-lived particles
have historically relied on the detection of displaced particles produced by
their decay the detector volume. In this paper we study the
potential of the complementary signature comprising of the missing transverse
energy () signal, traditionally used to look for dark matter, e.g.,
the lightest supersymmetric particle (LSP), to extend the LHC coverage to
models with long-lived (LL) particles when they decay the
detector. Using CMS and ATLAS analyses at the 8 TeV LHC, we set an upper limit
at the 95% confidence level (CL) on the production cross sections for two
specific scenarios: (i) a model with a heavy non-standard model Higgs boson
decaying to a LL scalar and (ii) an R-parity violating RPV SUSY model with a LL
neutralino.
We show that this method can significantly extend the LHC sensitivity to
neutral, LL particles with arbitrary large lifetimes and that the limits
obtained from a signal are comparable to those from displaced
particle searches for decay distances above a few meters. Results obtained in
this study do not not depend on the specific decay channel of the LL particle
and therefore are model-independent in this sense. We provide limits for the
whole two-dimensional plane in terms of the mass of the LL particle and the
mass of the mediator up to masses of 2 TeV including particular benchmarks
studied in the original experimental papers. We have made these limits
available in the form of a grid which can be used for the interpretation of
various other new physics models.Comment: 28 page
Gibberella musae (Fusarium musae) sp. nov., a recently discovered species from banana is sister to F. verticillioides
Several strains of Fusarium isolated from banana were identified previously as F. verticillioides (Sacc.) Nirenberg but described as unable to produce fumonisin. Here we report biochemical and morphological evidence, as well as multilocus phylogenetic analyses based on elongation factor (EF-1a), calmodulin, b-tubulin, and the second largest subunit of RNA polymerase II (RPB2) sequences, indicating that these isolates represent a unique lineage in the Gibberella fujikuroi species complex related to but distinct from F. verticillioides. Together with previous results of molecular studies, as well as with results of metabolite analyses, crossing experiments, pathogenicity tests and morphological characterization, these new data indicate that these strains isolated from banana represent a new species, Gibberella musae Van Hove et al. sp. nov. (anamorph: Fusarium musae Van Hove et al. sp. nov.), which is described herei
Hadamard states from null infinity
Free field theories on a four dimensional, globally hyperbolic spacetime,
whose dynamics is ruled by a Green hyperbolic partial differential operator,
can be quantized following the algebraic approach. It consists of a two-step
procedure: In the first part one identifies the observables of the underlying
physical system collecting them in a *-algebra which encodes their relational
and structural properties. In the second step one must identify a quantum
state, that is a positive, normalized linear functional on the *-algebra out of
which one recovers the interpretation proper of quantum mechanical theories via
the so-called Gelfand-Naimark-Segal theorem. In between the plethora of
possible states, only few of them are considered physically acceptable and they
are all characterized by the so-called Hadamard condition, a constraint on the
singular structure of the associated two-point function. Goal of this paper is
to outline a construction scheme for these states which can be applied whenever
the underlying background possesses a null (conformal) boundary. We discuss in
particular the examples of a real, massless conformally coupled scalar field
and of linearized gravity on a globally hyperbolic and asymptotically flat
spacetime.Comment: 23 pages, submitted to the Proceedings of the conference "Quantum
Mathematical Physics", held in Regensburg from the 29th of September to the
02nd of October 201
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