Version 4 (modified by druekeel, 2 years ago) (diff)

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# A Coloron Model

## Authors

• Elizabeth Drueke (Michigan State University)
• Joseph Nutter (Michigan State University)
• Reinhard Schwienhorst (Michigan State University)
• Natascia Vignaroli (Michigan State University)
• Devin G. E. Walker (SLAC National Accelerator Laboratory)
• Jiang-Hao Yu (The University of Texas at Austin)

## Description of the Model

The

breaking induced by the expectation value of the

scalar field Phi generates color-octet and color-singlet scalars. The most general renormalizable potential for Phi is:

where

and where, without loss of generality, one can choose mu > 0. Assuming

Phi acquires a (positive) diagonal expectation value:

The Phi expansion around the vacuum gives:

where

are singlets under SU(3)_C Additionally,

are the Nambu-Goldstone bosons associated with the color-symmetry breaking, and

are color octets.

GH can be produced in pairs through its interactions with gluons:

or it can be produced singly via gluon-gluon fusion. This occurs at one-loop order through the cubic interaction

which arises from the

term in the potential; where

is the SU(3) totally symmetric tensor. The single production of GH can be described by the effective coupling

with

Note that single production is suppressed by a factor

which is an accidental suppression factor coming from the loop. Above the threshold for decays into a single top quark, GH has two main decay modes: the decay into gluons, which occurs at loop-level similar to single coloron production, and the flavor-violating decay into tc. The corresponding rates are:

We set u=mu (the stability of the potential forbids mu>u); and consider for simplicity the set of

values that give a 50% GH decay into tc and 50% into gg. GH is a very narrow resonance, with a width of the order of 10-4 GeV.

Various Feynman Diagrams for GH processes discussed in 1409.7607v2 are shown below:

See more details in

## Generation specifics

In 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

p p > GH, GH > b c~ l+ vl @1 GHT=1 QED=2
p p > GH, GH > b~ c l- vl~ @2 GHT=1 QED=2


Specific masses can be generated using the appropriate model file from the Octet-tcgg zip file.