Changes between Version 1 and Version 2 of Octet_tcgg

10/28/15 16:16:34 (5 years ago)



  • Octet_tcgg

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     1= A Coloron Model =
     3== Authors ==
     5* Elizabeth Drueke (Michigan State University)
     6* Joseph Nutter (Michigan State University)
     7* Reinhard Schwienhorst (Michigan State University)
     8* Natascia Vignaroli (Michigan State University)
     9* Devin G. E. Walker (SLAC National Accelerator Laboratory)
     10* Jiang-Hao Yu (The University of Texas at Austin)
     12== Description of the Model ==
     14Colored vector bosons from new strong dynamics, Kaluza-Klein gluons or KKg’s (G*) in a dual 5D picture, have been searched for mainly in the t-tbar channel.  In this model, the third generation quarks couple differently than the light quarks under an extended
     17$SU(3)_1 \times SU(3)_2$
     19color gauge group.  The mixing between light and third generation quarks is induced by the interactions of all three generation quarks with a set of new heavy vector0like quarks.  The model reproduces the CKM mixing and generates flavor-changing neutral currents (FCNCs) from non-standard interactions.  Due to the specific structure of the model, dangerous FCNCs are naturally suppressed and a large portion of the model parameter space is allowed by the data on meson mixing process and on
     22$b \to \gamma$.
     24The extended color symmetry is broken down to
     29by the (diagonal) expectation value,
     32$\langle \Phi \rangle \propto u \cdot {\cal I}$,
     34of a scalar field Phi which transforms as a
     37$\bf 3, \bar{3}$
     39under the color gauge structure.  It is assumed that color gauge breaking occurs at a scale much higher than the electroweak scale.
     41Breaking the color symmetry induces a mixing between the
     44$SU(3)_1$ \rm{and} $SU(3)_2$
     46gauge fields
     49$A^{1}_{\mu}$ \rm{and} $A^{2}_{\mu}$,
     51which is diagonalized by a rotation determined by
     54$\cot\omega = \frac{g_1}{g_2} \qquad g_s = g_1 \sin\omega = g_2 \cos\omega$,
     56where g_s is the QCD strong coupling and g_1 and g_2 are the SU(3)_1 and SU(3)_2 gauge couplings, respectively.  The mixing diagonalization reveals two color vector boson mass eigenstates: the mass-less SM gluon and a new massive color-octet vector boson G* given by
     59$G^{*}_{\mu}=\cos\omega A^{1}_{\mu} - \sin\omega A^{2}_{\mu} \qquad M_{G^{*}} = \frac{g_s u}{\sin\omega \cos\omega}.$
     61In the NMFV model, the third generation quarks couple differently than the light quarks under the extended color group. 
     64$g_L=(t_L, b_L),$ \rm{ } $t_R,$ \rm{ and } $b_R,$
     66as well as a new weak-doublet of vector-like quarks, transform as
     69$({\bf 3,1})$
     71under the color gauge group, while the light generation quarks are charged under SU(3)_2 and transform as
     74$({\bf 1,3})$
     76The G* interactions with the color currents associated with SU(3)_1 and SU(3)_2 are given by
     79$g_s \left(\cot\omega J^{\mu}_1 - \tan\omega J^{\mu}_2 \right)G^{*}_{\mu}.$
     82== Note ==
     84Need to reread and make sure everything is the same as the paper and that nothing for KKg has been carried over.