58 research outputs found
Measuring the Higgs boson's parity using tau --> rho nu
We present a very promising method for a measurement of the Higgs boson
parity using the H/A -> tau^+ tau^- --> rho^+ nu rho^- nu --> pi^+ pi^0 nu pi^-
pi^0 nu decay chain. The method is both model independent and independent of
the Higgs production mechanism. Angular distributions of the tau decay products
which are sensitive to the Higgs boson parity are defined and are found to be
measurable using typical properties of a future detector for an e^+ e^- linear
collider. The prospects for the measurement of the parity of a Higgs boson with
a mass of 120 GeV are quantified for the case of e^+ e^- collisons of 500 GeV
center of mass energy with an integrated luminosity of 500 fb^-1. The Standard
Model Higgsstrahlung production process is used as an example.Comment: 10 pages, 4 figures, LaTeX, version of Phys. Lett.
Panel Discussion: Star Formation in Early-Type Galaxies
Original paper can be found at: http://www.astrosociety.org/pubs/cs/156-194.html--Copyright Astronomical Society of the PacificA panel discussion on past and current star formation in early-type galaxies was held on the second day of the conference. The panelists were Luc Binette, Elias Brinks, Paul Goudfrooij, Lisa Young, George Hau, Rick Pogge and Richard Bower, and the moderator was Jill Knapp. There was enthusiastic participation by the audience. Luc Binette opened the discussion by describing the data on the sources of ionization in the warm gas in elliptical galaxies, and Paul Goudfrooij followed by discussing what the metallicity of warm gas (HII regions) in elliptical galaxies has to say about the origin of that gas
Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays
Average charged multiplicities have been measured separately in , and
light quark () events from decays measured in the SLD experiment.
Impact parameters of charged tracks were used to select enriched samples of
and light quark events, and reconstructed charmed mesons were used to select
quark events. We measured the charged multiplicities:
,
, from
which we derived the differences between the total average charged
multiplicities of or quark events and light quark events: and . We compared
these measurements with those at lower center-of-mass energies and with
perturbative QCD predictions. These combined results are in agreement with the
QCD expectations and disfavor the hypothesis of flavor-independent
fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters
On the spin distributions of CDM haloes
We used merger trees realizations, predicted by the extended Press-Schechter
theory, in order to study the growth of angular momentum of dark matter haloes.
Our results showed that: 1) The spin parameter resulting from the
above method, is an increasing function of the present day mass of the halo.
The mean value of varies from 0.0343 to 0.0484 for haloes with
present day masses in the range of to
. 2)The distribution of is close to
a log-normal, but, as it is already found in the results of N-body simulations,
the match is not satisfactory at the tails of the distribution. A new
analytical formula that approximates the results much more satisfactorily is
presented. 3) The distribution of the values of depends only weakly
on the redshift. 4) The spin parameter of an halo depends on the number of
recent major mergers. Specifically the spin parameter is an increasing function
of this number.Comment: 10 pages, 8 figure
Model-independent analysis of Higgs spin and CP properties in the process
In this paper we investigate methods to study the Higgs coupling.
The spin and CP properties of a Higgs boson are analysed in a model-independent
way in its associated production with a pair in high-energy
collisions. We study the prospects of establishing the CP quantum numbers of
the Higgs boson in the CP-conserving case as well as those of determining the
CP-mixing if CP is violated. We explore in this analysis the combined use of
the total cross section and its energy dependence, the polarisation asymmetry
of the top quark and the up-down asymmetry of the antitop with respect to the
top-electron plane. We find that combining all three observables remarkably
reduces the error on the determination of the CP properties of the Higgs Yukawa
coupling. Furthermore, the top polarisation asymmetry and the ratio of cross
sections at different collider energies are shown to be sensitive to the spin
of the particle produced in association with the top quark pair
Extended Theories of Gravity and their Cosmological and Astrophysical Applications
We review Extended Theories of Gravity in metric and Palatini formalism
pointing out their cosmological and astrophysical application. The aim is to
propose an alternative approach to solve the puzzles connected to dark
components.Comment: 44 pages, 11 figure
Using Visible and near Infrared Spectroscopy to Estimate Carbonates and Gypsum in Soils in Arid and Subhumid Regions of Isfahan, Iran
Effects of anaesthetics on the water parameters in a simulated transport experiment of platyfish, Xiphophorus maculatus (Günther)
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