1 | | bla |
| 1 | = A Coloron Model = |
| 2 | |
| 3 | == Authors == |
| 4 | |
| 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) |
| 11 | |
| 12 | == Description of the Model == |
| 13 | |
| 14 | Colored 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 |
| 15 | {{{ |
| 16 | #!latex |
| 17 | $SU(3)_1 \times SU(3)_2$ |
| 18 | }}} |
| 19 | color 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 |
| 20 | {{{ |
| 21 | #!latex |
| 22 | $b \to \gamma$. |
| 23 | }}} |
| 24 | The extended color symmetry is broken down to |
| 25 | {{{ |
| 26 | #!latex |
| 27 | $SU(3)_C$ |
| 28 | }}} |
| 29 | by the (diagonal) expectation value, |
| 30 | {{{ |
| 31 | #!latex |
| 32 | $\langle \Phi \rangle \propto u \cdot {\cal I}$, |
| 33 | }}} |
| 34 | of a scalar field Phi which transforms as a |
| 35 | {{{ |
| 36 | #!latex |
| 37 | $\bf 3, \bar{3}$ |
| 38 | }}} |
| 39 | under the color gauge structure. It is assumed that color gauge breaking occurs at a scale much higher than the electroweak scale. |
| 40 | |
| 41 | Breaking the color symmetry induces a mixing between the |
| 42 | {{{ |
| 43 | #!latex |
| 44 | $SU(3)_1$ \rm{and} $SU(3)_2$ |
| 45 | }}} |
| 46 | gauge fields |
| 47 | {{{ |
| 48 | #!latex |
| 49 | $A^{1}_{\mu}$ \rm{and} $A^{2}_{\mu}$, |
| 50 | }}} |
| 51 | which is diagonalized by a rotation determined by |
| 52 | {{{ |
| 53 | #!latex |
| 54 | $\cot\omega = \frac{g_1}{g_2} \qquad g_s = g_1 \sin\omega = g_2 \cos\omega$, |
| 55 | }}} |
| 56 | where 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 |
| 57 | {{{ |
| 58 | #!latex |
| 59 | $G^{*}_{\mu}=\cos\omega A^{1}_{\mu} - \sin\omega A^{2}_{\mu} \qquad M_{G^{*}} = \frac{g_s u}{\sin\omega \cos\omega}.$ |
| 60 | }}} |
| 61 | In the NMFV model, the third generation quarks couple differently than the light quarks under the extended color group. |
| 62 | {{{ |
| 63 | #!latex |
| 64 | $g_L=(t_L, b_L),$ \rm{ } $t_R,$ \rm{ and } $b_R,$ |
| 65 | }}} |
| 66 | as well as a new weak-doublet of vector-like quarks, transform as |
| 67 | {{{ |
| 68 | #!latex |
| 69 | $({\bf 3,1})$ |
| 70 | }}} |
| 71 | under the color gauge group, while the light generation quarks are charged under SU(3)_2 and transform as |
| 72 | {{{ |
| 73 | #!latex |
| 74 | $({\bf 1,3})$ |
| 75 | }}} |
| 76 | The G* interactions with the color currents associated with SU(3)_1 and SU(3)_2 are given by |
| 77 | {{{ |
| 78 | #!latex |
| 79 | $g_s \left(\cot\omega J^{\mu}_1 - \tan\omega J^{\mu}_2 \right)G^{*}_{\mu}.$ |
| 80 | }}} |
| 81 | |
| 82 | == Note == |
| 83 | |
| 84 | Need to reread and make sure everything is the same as the paper and that nothing for KKg has been carried over. |