Changes between Version 2 and Version 3 of kkg_FV


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Timestamp:
11/03/15 16:11:04 (19 months ago)
Author:
druekeel
Comment:

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  • kkg_FV

    v2 v3  
    1414Colored 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.  The analysis in [http://arxiv.org/pdf/1409.7607v2.pdf 1409.7607v2] analyzes the tc decay as depicted below: 
    1515[[Image(wiki:KKg.png)]] 
    16 In this model, the third generation quarks couple differently than the light quarks under an extended  
     16The benchmark adopted here is a simple renormalizable model of an 
     17extended color gauge sector, which realizes next-to-minimal flavor violation (NMFV). In this model, the third generation quarks couple differently than the light quarks under an extended  
    1718{{{ 
    1819#!latex 
    1920$SU(3)_1 \times SU(3)_2$ 
    2021}}} 
    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 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  
     22color 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-like 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  
    2223{{{ 
    2324#!latex 
    24 $b \to \gamma$. 
     25$b \to s\gamma$. 
     26}}} 
     27The model has the color gauge structure 
     28{{{ 
     29#!latex 
     30$SU(3)_1 \times SU(3)_2$ 
    2531}}} 
    2632The extended color symmetry is broken down to  
     
    3743{{{ 
    3844#!latex 
    39 $\bf 3, \bar{3}$ 
     45$(\bf 3, \bar{3})$ 
    4046}}} 
    41 under the color gauge structure.  It is assumed that color gauge breaking occurs at a scale much higher than the electroweak scale. 
     47under the color gauge structure.  It is assumed that color gauge breaking occurs at a scale much higher than the electroweak scale, u>>v. 
    4248 
    4349Breaking the color symmetry induces a mixing between the  
     
    5662$\cot\omega = \frac{g_1}{g_2} \qquad g_s = g_1 \sin\omega = g_2 \cos\omega$, 
    5763}}} 
    58 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 
     64where 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 mass-less SM gluon and a new massive color-octet vector boson G* given by 
    5965{{{ 
    6066#!latex 
     
    8389 
    8490 
    85 G*'s form an extended color group and can be produced at the LHC by quark-antiquark fusion determined by the G* coupling to light quarks  
     91The G* can be produced at the LHC by quark-antiquark fusion determined by the G* coupling to light quarks  
    8692{{{ 
    8793#!latex 
     
    102108$\Gamma[G^{*} \to t_L \bar c_L]=\Gamma[G^{*} \to c_L \bar t_L]\simeq \left(V_{cb}\right)^2 \frac{g^2_s}{48\pi} M_{G^{*}} \left( \cot\omega+\tan\omega \right)^2,$ 
    103109}}} 
    104 where V_cb=0.0415$ is the CKM matrix element. Note here that G* FCNCs are induced by the mixing among left-handed quarks generated by the exchange of heavy vector-like quarks. This mixing is controlled by the 3x3 matrices U_L and D_L in the up- and down-quark sectors, respectively. In particular, the G* to tc flavor violating decay is controlled by the  
     110where  
     111{{{ 
     112#!latex 
     113$V_{cb}=0.0415$ 
     114}}} 
     115is the CKM matrix element. Note here that G* FCNCs are induced by the mixing among left-handed quarks generated by the exchange of heavy vector-like quarks. This mixing is controlled by the 3x3 matrices U_L and D_L in the up- and down-quark sectors, respectively. In particular, the  
     116{{{ 
     117#!latex 
     118$G* \to tc$ 
     119}}} 
     120flavor violating decay is controlled by the  
    105121{{{ 
    106122#!latex 
     
    120136{{{ 
    121137#!latex 
    122 $b\to s \gamma$. \rm{So } $(D_L)_{23}$ 
     138$b\to s \gamma$.  
     139}}} 
     140So 
     141{{{ 
     142#!latex 
     143$(D_L)_{23}$ 
    123144}}} 
    124145is thus forced to be small and, as a consequence,  
     
    127148$(U_L)_{23}\simeq V_{cb}$. 
    128149}}} 
     150See more details in 
     151* [http://arxiv.org/pdf/1409.7607v2.pdf 1409.7607v2] 
     152* [http://arxiv.org/pdf/1412.3094.pdf 1412.3094] 
    129153 
    130 == Note == 
     154== Model Files == 
    131155 
    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    
     162In [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 pre-included !MadGraph cuts as demonstrated in the run_card.dat for 500 GeV mass included above.  The specific generations run were  
     163{{{ 
     164p p > kkg > b~ c l- vl~ @1 
     165p p > kkg > b c~ l+ vl @2 
     166}}} 
     167To 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).