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Archivio digitale delle tesi discusse presso l’Università di Pisa

Tesi etd-09142009-233035


Tipo di tesi
Tesi di laurea specialistica
Autore
DEL NOBILE, EUGENIO
URN
etd-09142009-233035
Titolo
Minimal matter at LHC
Dipartimento
SCIENZE MATEMATICHE, FISICHE E NATURALI
Corso di studi
SCIENZE FISICHE
Relatori
relatore Strumia, Alessandro
Parole chiave
  • exotic particles
Data inizio appello
16/10/2009
Consultabilità
Completa
Riassunto
It is usually assumed that new particles carry a new conserved quantum number due to a new symmetry not included in the Standard Model (SM), e.g. in the Supersymmetry scenario. In this work instead we consider a dfferent approach, `orthogonal' to the previous one, i.e. we add to the Standard Model a new multiplet with mass term and renormalizable Yukawa couplings
to SM particles, so that the lagrangian is restricted only by imposing the SM Lorentz and Gauge symmetries and not by new ones. We classify all possible new U(1)Y x SU(2)L x SU(3)c multiplets that can couple to pairs of SM particles and then study the signals at CERN's Large Hadron Collider (LHC) of some of them. In order to make these analysis we calculate the general production cross-section by quark-antiquark and gluongluon scattering assuming that production of such new particles is dominated by their gauge interactions. The non trivial couplings to SM particles and to Gauge bosons and the decay rates are determined by the more general lagrangian for these massive particles. We then study their most promising final states and propose selection cuts in order to improve their visibility over the SM background. The background has been generated with the Monte Carlo program MadGraph/MadEvent, while the generation of signal events and the processing of the whole set of data have been done with a Mathematica code written by Dr. A. Strumia (and a little improved by the undersigned).
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