Alexandre Alves - Academia.edu (original) (raw)
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Papers by Alexandre Alves
Physical Review D, 2012
Within the 3-3-1 model framework, we consider the production and decay of fermionic leptoquarks i... more Within the 3-3-1 model framework, we consider the production and decay of fermionic leptoquarks into a striking experimental signature at the LHC: a narrow resonance at the b jet plus same-sign dileptons channel. The data already accumulated by the LHC collaborations may hide a large number of events associated to the production and decay of such exotic quarks, allowing one to investigate large portions of the parameters space of the model. The observation or not of such events would shed light on the construction of models presenting heavy exotic quarks.
Physical Review D, 2015
We study dark matter (DM) production in the mono-Z channel at the 13 TeV LHC both in an effective... more We study dark matter (DM) production in the mono-Z channel at the 13 TeV LHC both in an effective field theory framework as well as in simplified models with vector mediators, using a multivariate analysis. For DM-quark effective operators with scalar, vector, and tensor couplings and DM mass of 100 GeV, the 5σ reach in the DM interaction scale Λ is around 2, 1, and 3 TeV, respectively, for 3 ab −1 and assuming a 5% systematic uncertainty on the total background normalization. For simplified models with leptophobic vector mediators, the 5σ reach for the mass of the mediator is 1.7 TeV also assuming a 5% systematics and 3 ab −1 of integrated luminosity. The reach for the dark matter interaction scale obtained with the multivariate analysis using a likelihood function discriminant is at least twice as high as that obtained from a simple cut and count analysis, once systematics on the background normalization larger than a few percent are taken into account. Moreover, the reach is much more stable against degradation due to these systematic uncertainties.
Physical Review D, 2010
Triggering the electroweak symmetry breaking may not be the only key role played by the Higgs bos... more Triggering the electroweak symmetry breaking may not be the only key role played by the Higgs boson in particle physics. In a recently proposed warped five-dimensional SO(5) ⊗ U (1) gauge-Higgs unification model the Higgs boson can also constitute the dark matter that permeates the universe. The stability of the Higgs boson in this model is guaranteed in all orders of perturbation theory by the conservation of an H-parity quantum number that forbids triple couplings to all SM particles. Such a unique feature of the model shows up as a delay in the restoration of the tree-level unitarity which in turn enhances the production cross section as compared to the standard model analogue. Recent astrophysical data constrain the mass of such a Higgs dark matter particle to a narrow window of 70-90 GeV range. We show that the Large Hadron Collider can observe these Higgs bosons in the weak boson fusion channel with about 260 fb −1 of integrated luminosity in that mass range.
Acta Scientiarum. Animal Sciences, 2004
High-Performance Computing and …, 1995
This paper presents WPVM, a PVM implementation for the "MS Windows" - Microsoft Windows... more This paper presents WPVM, a PVM implementation for the "MS Windows" - Microsoft Windows Operating System 1 . WPVM stands for "Windows Parallel Virtual Machine" and intends to exploit the potential computational power of the small and medium PC LANs that proliferate in ...
Physical Review D, 2012
Within the 3-3-1 model framework, we consider the production and decay of fermionic leptoquarks i... more Within the 3-3-1 model framework, we consider the production and decay of fermionic leptoquarks into a striking experimental signature at the LHC: a narrow resonance at the b jet plus same-sign dileptons channel. The data already accumulated by the LHC collaborations may hide a large number of events associated to the production and decay of such exotic quarks, allowing one to investigate large portions of the parameters space of the model. The observation or not of such events would shed light on the construction of models presenting heavy exotic quarks.
Physical Review D, 2015
We study dark matter (DM) production in the mono-Z channel at the 13 TeV LHC both in an effective... more We study dark matter (DM) production in the mono-Z channel at the 13 TeV LHC both in an effective field theory framework as well as in simplified models with vector mediators, using a multivariate analysis. For DM-quark effective operators with scalar, vector, and tensor couplings and DM mass of 100 GeV, the 5σ reach in the DM interaction scale Λ is around 2, 1, and 3 TeV, respectively, for 3 ab −1 and assuming a 5% systematic uncertainty on the total background normalization. For simplified models with leptophobic vector mediators, the 5σ reach for the mass of the mediator is 1.7 TeV also assuming a 5% systematics and 3 ab −1 of integrated luminosity. The reach for the dark matter interaction scale obtained with the multivariate analysis using a likelihood function discriminant is at least twice as high as that obtained from a simple cut and count analysis, once systematics on the background normalization larger than a few percent are taken into account. Moreover, the reach is much more stable against degradation due to these systematic uncertainties.
Physical Review D, 2010
Triggering the electroweak symmetry breaking may not be the only key role played by the Higgs bos... more Triggering the electroweak symmetry breaking may not be the only key role played by the Higgs boson in particle physics. In a recently proposed warped five-dimensional SO(5) ⊗ U (1) gauge-Higgs unification model the Higgs boson can also constitute the dark matter that permeates the universe. The stability of the Higgs boson in this model is guaranteed in all orders of perturbation theory by the conservation of an H-parity quantum number that forbids triple couplings to all SM particles. Such a unique feature of the model shows up as a delay in the restoration of the tree-level unitarity which in turn enhances the production cross section as compared to the standard model analogue. Recent astrophysical data constrain the mass of such a Higgs dark matter particle to a narrow window of 70-90 GeV range. We show that the Large Hadron Collider can observe these Higgs bosons in the weak boson fusion channel with about 260 fb −1 of integrated luminosity in that mass range.
Acta Scientiarum. Animal Sciences, 2004
High-Performance Computing and …, 1995
This paper presents WPVM, a PVM implementation for the "MS Windows" - Microsoft Windows... more This paper presents WPVM, a PVM implementation for the "MS Windows" - Microsoft Windows Operating System 1 . WPVM stands for "Windows Parallel Virtual Machine" and intends to exploit the potential computational power of the small and medium PC LANs that proliferate in ...