8,687 research outputs found
Electroweak Physics in Six-Fermion Processes at Future Colliders
Recent developments in the field of complete electroweak tree-level
calculations for six-fermion final states in e+ e- collisions are briefly
reviewed. Particular attention is given to top-quark and Higgs boson physics,
which are items of primary importance at the Next Linear Collider. The
relevance of electroweak backgrounds and finite-width effects is discussed,
showing the importance of complete calculations for precision studies at the
colliders operating in the TeV energy range.Comment: LaTeX (using npb style), 6 pages, 5 .eps figure
Spectrum of Higgs particles in the Exceptional Supersymmetric Standard Model
We discuss the spectrum of Higgs bosons in the framework of the exceptional
supersymmetric standard model. The presence of a and exotic particles
predicted by the exceptional SUSY model allows the lightest Higgs particle to
be significantly heavier than in the MSSM and NMSSM. When the mass of the
lightest Higgs boson is larger than the heaviest scalar,
pseudoscalar and charged Higgs states lie beyond the range.Comment: Presented at 12th Lomonosov Conference on Elementary Particle
Physics, Moscow, Russia, 25-31 August 2005, some minor changes to the text,
references adde
The constrained E6SSM
We discuss the predictions of a constrained version of the exceptional
supersymmetric standard model (cE6SSM), with a universal high energy soft
scalar mass, soft trilinear coupling and soft gaugino mass. The spectrum
includes a light gluino, a light wino-like neutralino and chargino pair and a
light bino-like neutralino, with other sparticle masses except the lighter stop
being much heavier. We also discuss scenarios with an extra light exotic colour
triplet of fermions and scalars and a TeV scale Z', which lead to early exotic
physics signals at the LHC.Comment: To appear in proceedings of The 2009 Europhysics Conference on High
Energy Physics, 16-22 July 2009 Krakow, Poland; 4 page
The Geography of Giving: The Effect of Corporate Headquarters on Local Charities
We use data on the locations of the head offices of publicly traded U.S. firms to study the impact of corporate headquarters on the receipts of local charitable organizations. Cities like Houston, San Jose, and San Francisco gained significant numbers of corporate headquarters over the past two decades, while cities like Chicago and Los Angeles lost. Our analysis suggests that attracting or retaining the headquarters of an average firm yields approximately 25 million per year. Likewise, we find that each $1000 increase in the market value of the firms headquartered in a city yields 70 cents or more to local non-profits. Most of the increase in charitable contributions arises from an effect on the number of highly-compensated individuals in a city, rather than through direct donations by the corporations themselves
Six-fermion production and Higgs boson physics at future colliders
The six-fermion production processes ,
with all the lepton flavours and , relevant to the study of the
intermediate-mass Higgs boson at future linear colliders, are
analysed. A Monte Carlo program, taking into account the whole set of
tree-level scattering amplitudes and the relevant radiative effects, is
developed to provide integrated cross sections and generation of unweighted
events. The complete calculation is compared with the available results of real
Higgs production, and the opportunities of precision studies with event
generation are discussed, demonstrating the relevance of a full six-fermion
calculation. Numerical results for integrated cross sections with various
kinematical cuts and including radiative effects are given and commented. In
the analysis of event samples, several distributions are studied and found to
be sensitive to the presence and to the properties of the Higgs boson.Comment: LaTeX, 27 pages, 13 figures included. Minor changes, final version to
appear in Eur. Phys. J.
Six-Fermion Calculation of Intermediate-mass Higgs Boson Production at Future Colliders
The production of an intermediate-mass Higgs boson in processes of the kind
fermions at the energies of future linear colliders is studied.
The recently developed and fully automatic algorithm/code ALPHA is used to
compute the tree-level scattering amplitudes for the reactions . The code has been interfaced with the Monte Carlo program HIGGSPV/WWGENPV,
properly adapted to 6-fermion production, in order to provide realistic
results, both in the form of cross sections and event samples at the partonic
level. Phenomenological results, that incorporate the effects of initial-state
radiation and beamstrahlung, are shown and commented, emphasizing the
potentials of full six-fermion calculations for precise background evaluation
as well as for detailed studies of the fundamental properties of the Higgs
particle.Comment: 31 pages, LaTeX, 15 eps low-resolution figures include
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