389 research outputs found
Pairs of charged heavy-leptons from an SU(3) X U(1) model at CERN LHC
One of the versions of the SU(3)_L\otimesU(1)_N electroweak model predicts
charged heavy-leptons which do not belong to any class of heavy-leptons
proposed up to now. We investigate the production and signatures of pairs of
these heavy-leptons {\it via} the Drell-Yan process and the gluon-gluon fusion
at the CERN Large Hadron Collider (LHC). As an example we study the decay of
the exotic leptons into another ones. We see that the lifetime of the exotic
leptons can be short.Comment: 12 pages, 8 figures, Revtex4, Version published in Nucl. Phys.
Pair of Heavy-Exotic-Quarks at LHC
We study the production and signatures of heavy exotic quarks pairs at LHC in
the framework of the vector singlet model (VSM), vector doublet model (VDM) and
fermion-mirror-fermion (FMF) model. The pair production cross sections for the
electroweak and strong sector are computed.Comment: 7 pages, 6 figures. accept at Int. Jour. of Mod. Phy
Probing doubly charged Higgs in Colliders in 3-3-1 Model
The SU(3)_L\otimesU(1)_N electroweak model predicts new Higgs bosons beyond
the one of the standard model. In this work we investigate the signature and
production of doubly charged Higgs bosons in the International Linear
Collider and in the CERN Linear Collider. We compute the branching ratios for
the doubly charged gauge bosons of the model.Comment: 17 pages, 12 figure
Search for the Higgs Boson at LHC in 3-3-1 Model
We present an analysis of production and signature of neutral Higgs boson
() on the version of the 3-3-1 model containing heavy leptons at the
Large Hadron Collider. We studied the possibility to identify it using the
respective branching ratios. Cross section are given for the collider energy,
14 TeV. Event rates and significances are discussed for two
possible values of integrated luminosity, 300 fb and 3000 fb.Comment: 17 pages 7 figures. arXiv admin note: substantial text overlap with
arXiv:1205.404
Evidence for J and H-band excess in classical T Tauri stars and the implications for disk structure and estimated ages
We argue that classical T Tauri stars (cTTs) possess significant non-
photospheric excess in the J and H bands. We first show that normalizing the
spectral energy distributions (SEDs) of cTTs to the J-band leads to a poor fit
of the optical fluxes, while normalizing the SEDs to the Ic-band produces a
better fit to the optical bands and in many cases reveals the presence of a
considerable excess at J and H. NIR spectroscopic veiling measurements from the
literature support this result. We find that J and H-band excesses correlate
well with the K-band excess, and that the J-K and H-K colors of the excess
emission are consistent with that of a black body at the dust sublimation
temperature (~ 1500-2000 K). We propose that this near-IR excess originates at
a hot inner rim, analogous to those suggested to explain the near-IR bump in
the SEDs of Herbig Ae/Be stars. To test our hypothesis, we use the model
presented by Dullemond et al. (2001) to fit the photometry data between 0.5 um
and 24 um of 10 cTTs associated with the Chamaeleon II molecular cloud. The
models that best fit the data are those where the inner radius of the disk is
larger than expected for a rim in thermal equilibrium with the photospheric
radiation field alone. In particular, we find that large inner rims are
necessary to account for the mid infrared fluxes (3.6-8.0 um) obtained by the
Spitzer Space Telescope. Finally, we argue that deriving the stellar
luminosities of cTTs by making bolometric corrections to the J-band fluxes
systematically overestimates these luminosities. The overestimated luminosities
translate into underestimated ages when the stars are placed in the H-R
diagram. Thus, the results presented herein have important implications for the
dissipation timescale of inner accretion disks.Comment: 45 pages, 13 figure
t-channel production of heavy charged leptons
We study the pair production of heavy charged exotic leptons at e+ e-
colliders in the SU(2)_L x SU(2)_I x U(1)_Y model. This gauge group is a
subgroup of the grand unification group E6; SU(2)_I commutes with the electric
charge operator, and the three corresponding gauge bosons are electrically
neutral. In addition to the standard photon and Z boson contributions, we also
include the contributions from extra neutral gauge bosons. A t-channel
contribution due to W_I-boson exchange, which is unsuppressed by mixing angles,
is quite important. We calculate the left-right and forward-backward
asymmetries, and discuss how to differentiate different models.Comment: Increased discussion of experimental signatures. Version accepted by
PR
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