23 research outputs found
Gravitational Laser Back-Scattering
A possible way of producing gravitons in the laboratory is investigated. We
evaluate the cross section electron + photon electron + graviton
in the framework of linearized gravitation, and analyse this reaction
considering the photon coming either from a laser beam or from a Compton
back-scattering process.Comment: 11 pages, 2 figures (available upon request), RevTeX, IFT-P.03/9
Identifying the Higgs Boson in Electron--Photon Collisions
We analyze the production and detection of the Higgs boson in the next
generation of linear colliders operating in the mode. In
particular, we study the production mechanism , where one photon is generated via the laser
backscattering mechanism, while the other is radiated via the usual
bremsstrahlung process. We show that this is the most important mechanism for
Higgs boson production in a GeV collider for
M_H\raisebox{-.4ex}{\rlap{\sim}} \raisebox{.4ex}{>}140 GeV. We also study
the signals and backgrounds for detection of the Higgs in the different decay
channels, , , and , and suggest kinematical cuts to
improve the signature of an intermediate mass Higgs boson.Comment: (REVTEX 2.0, 12 pages and 9 figures available upon request, Preprint
MAD/PH/753
Quartic Anomalous Couplings in Colliders
We study the constraints on the vertices ,
, and that can be obtained from
triple-gauge-boson production at the next generation of linear
colliders operating in the mode. We analyze the processes
(, or ) and show that these reactions
increase the potential of machines to search for anomalous
four-gauge-boson interactions.Comment: 15 pages, Latex file using ReVteX, 4 uufiled figures include
Discriminating New Physics Scenarios at NLC: The Role of Polarization
We explore the potential of the Next Linear Collider (NLC), operating in the
mode, to disentangle new physics scenarios on single production.
We study the effects related with the exchange of composite fermion in the
reaction , and compare with those arising from trilinear
gauge boson anomalous couplings. We stress the role played by the initial state
polarization to increase the reach of this machine and to discriminate the
possible origin of the new phenomena.Comment: 26 pages, LaTeX file using ReVTeX. 10 Figure
Anomalous g^5_z coupling at colliders
We study the constraints on the anomalous coupling that can be
obtained from the analysis of the reaction
at future linear colliders. We find out that a () TeV
collider operating in the mode can probe values of
of the order of () for an integrated
luminosity of fb. This shows that the ability to search for this
anomalous interaction of the mode is better than the one of the
usual mode, and it is similar to the ability of the mode.Comment: 12 pages, 4 figures as uudecoded ps file
Excited Leptonic States in Polarized e^-\gamma and e^+ e^- Collisions
We analyze the capability of the next generation of linear electron--positron
colliders to unravel the spin and couplings of excited leptons predicted by
composite models. Assuming that these machines will be able to operate both in
the and modes, we study the effects of the excited
electrons of spin and in the reactions and . We show how the
use of polarized beams is able not only to increase the reach of these
machines, but also to determine the spin and couplings of the excited states.Comment: 22 pages, RevTeX, 8 figure
Threshold Effects on Heavy Quark Production in Interactions
The exchange of gluons between heavy quarks produced in interactions
results in an enhancement of their production near threshold. We study QCD
threshold effects in collisions. The results are relevant to
heavy quark production by beamstrahlung and laser back-scattering in future
linear collider experiments. Detailed predictions for top, bottom and charm
production are presented.Comment: 26 pages, 12 figures available in ps upon request, revtex, MAD/PH/701
(revised version
Measuring the gamma gamma coupling of the Higgs boson at linear colliders
Observing the production of the Higgs particle in the
γ
γ
mode of a linear
e
+
e
−
collider allows for the measurement of the
H
γ
γ
coupling. We point out that for the intermediate Higgs mass range this measurement is considerably more challenging than previously believed. The
b
¯
b
signature receives a large background from the production of heavy quark pairs by resolved photons. We quantify the experimental requirements needed to make a meaningful measurement in the presence of this background