Changes between Version 2 and Version 3 of kkg_FV
 Timestamp:
 Nov 3, 2015 4:11:04 PM (3 years ago)
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kkg_FV
v2 v3 14 14 Colored vector bosons from new strong dynamics, KaluzaKlein gluons or KKg’s (G*) in a dual 5D picture, have been searched for mainly in the ttbar channel. The analysis in [http://arxiv.org/pdf/1409.7607v2.pdf 1409.7607v2] analyzes the tc decay as depicted below: 15 15 [[Image(wiki:KKg.png)]] 16 In this model, the third generation quarks couple differently than the light quarks under an extended 16 The benchmark adopted here is a simple renormalizable model of an 17 extended color gauge sector, which realizes nexttominimal flavor violation (NMFV). In this model, the third generation quarks couple differently than the light quarks under an extended 17 18 {{{ 18 19 #!latex 19 20 $SU(3)_1 \times SU(3)_2$ 20 21 }}} 21 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 vector 0like quarks. The model reproduces the CKM mixing and generates flavorchanging neutral currents (FCNCs) from nonstandard 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 on22 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 vectorlike quarks. The model reproduces the CKM mixing and generates flavorchanging neutral currents (FCNCs) from nonstandard 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 23 {{{ 23 24 #!latex 24 $b \to \gamma$. 25 $b \to s\gamma$. 26 }}} 27 The model has the color gauge structure 28 {{{ 29 #!latex 30 $SU(3)_1 \times SU(3)_2$ 25 31 }}} 26 32 The extended color symmetry is broken down to … … 37 43 {{{ 38 44 #!latex 39 $ \bf 3, \bar{3}$45 $(\bf 3, \bar{3})$ 40 46 }}} 41 under the color gauge structure. It is assumed that color gauge breaking occurs at a scale much higher than the electroweak scale .47 under the color gauge structure. It is assumed that color gauge breaking occurs at a scale much higher than the electroweak scale, u>>v. 42 48 43 49 Breaking the color symmetry induces a mixing between the … … 56 62 $\cot\omega = \frac{g_1}{g_2} \qquad g_s = g_1 \sin\omega = g_2 \cos\omega$, 57 63 }}} 58 where g_s is the QCD strong coupling and g_1 andg_2 are the SU(3)_1 and SU(3)_2 gauge couplings, respectively. The mixing diagonalization reveals two color vector boson mass eigenstates: the massless SM gluon and a new massive coloroctet vector boson G* given by64 where g_s is the QCD strong coupling and g_1, 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 massless SM gluon and a new massive coloroctet vector boson G* given by 59 65 {{{ 60 66 #!latex … … 83 89 84 90 85 G*'s form an extended color group andcan be produced at the LHC by quarkantiquark fusion determined by the G* coupling to light quarks91 The G* can be produced at the LHC by quarkantiquark fusion determined by the G* coupling to light quarks 86 92 {{{ 87 93 #!latex … … 102 108 $\Gamma[G^{*} \to t_L \bar c_L]=\Gamma[G^{*} \to c_L \bar t_L]\simeq \left(V_{cb}\right)^2 \frac{g^2_s}{48\pi} M_{G^{*}} \left( \cot\omega+\tan\omega \right)^2,$ 103 109 }}} 104 where V_cb=0.0415$ is the CKM matrix element. Note here that G* FCNCs are induced by the mixing among lefthanded quarks generated by the exchange of heavy vectorlike quarks. This mixing is controlled by the 3x3 matrices U_L and D_L in the up and downquark sectors, respectively. In particular, the G* to tc flavor violating decay is controlled by the 110 where 111 {{{ 112 #!latex 113 $V_{cb}=0.0415$ 114 }}} 115 is the CKM matrix element. Note here that G* FCNCs are induced by the mixing among lefthanded quarks generated by the exchange of heavy vectorlike quarks. This mixing is controlled by the 3x3 matrices U_L and D_L in the up and downquark sectors, respectively. In particular, the 116 {{{ 117 #!latex 118 $G* \to tc$ 119 }}} 120 flavor violating decay is controlled by the 105 121 {{{ 106 122 #!latex … … 120 136 {{{ 121 137 #!latex 122 $b\to s \gamma$. \rm{So } $(D_L)_{23}$ 138 $b\to s \gamma$. 139 }}} 140 So 141 {{{ 142 #!latex 143 $(D_L)_{23}$ 123 144 }}} 124 145 is thus forced to be small and, as a consequence, … … 127 148 $(U_L)_{23}\simeq V_{cb}$. 128 149 }}} 150 See more details in 151 * [http://arxiv.org/pdf/1409.7607v2.pdf 1409.7607v2] 152 * [http://arxiv.org/pdf/1412.3094.pdf 1412.3094] 129 153 130 == Note==154 == Model Files == 131 155 132 Need to reread and make sure everything is the same as paper. 156 * [attachment:proc_card_mg5.dat proc_card]: for generation of 500 GeV KKg (place in Cards/) 157 * [attachment:run_card.dat run_card]: for generation of 500 GeV KKg (place in Cards/) 158 * [attachment:kkg_FV.zip kkg_FV]: the model and parameter cards for specific mass generations 159 160 == Generation specifics == 161 162 In [http://arxiv.org/pdf/1409.7607v2.pdf 1409.7607v2], the samples were generated with the mass as the scale, dsqrt_q2fact1, and dsqrt_q2fact2 in the run_card. These samples were also generated without the preincluded !MadGraph cuts as demonstrated in the run_card.dat for 500 GeV mass included above. The specific generations run were 163 {{{ 164 p p > kkg > b~ c l vl~ @1 165 p p > kkg > b c~ l+ vl @2 166 }}} 167 To generate a specific mass, param_card.dat in the generation file to the card of the appropriate mass in the param_cards directory (included as part of the model zip file).