Compositeness Processes
Compositeness scenarios may give rise to sharp resonances of excited
quarks and leptons. An excited copy of the first generation is
implemented, consisting of spin 1/2 particles. The possibility of
contact interactions between SM fermions is also implemented in the
context of 2 -> 2 quark or fermion-lepton scattering.
Related to excited fermions, the current implementation contains gauge
interaction production by quark-gluon fusion or lepton-photon fusion
and contact interaction production by quark-quark or quark-antiquark
scattering. For both the 2 -> 1 and 2 -> 2 processes
a non-trivial angular dependence is included in the decay, however,
only decays into gauge bosons are supported, i.e. not decays through
contact interactions. In additions to the compositeness scale and couplings
listed below, you are expected to change the excited-fermion masses in
accordance with what is desired. See [Bau90] for conventions.
The contact interactions are implemented according to [Eic83].
The processes include the SM contributions as well as interference.
For this reason the processes below converge toward the SM equivalents
when the contact interaction contributions are close to zero, e.g.
HardQCD:qq2qq
and HardQCD:qqbar2qqbarNew
in
the case of quark scattering.
Excited fermions, production processes
A few different production processes have been implemented, which normally
would not overlap and therefore could be run together.
flag
ExcitedFermion:all
(default = off
)
Common switch for the group of implemented processes that produce an
excited fermion.
flag
ExcitedFermion:dg2dStar
(default = off
)
Scatterings d g -> d^*.
Code 4001.
flag
ExcitedFermion:ug2uStar
(default = off
)
Scatterings u g -> u^*.
Code 4002.
flag
ExcitedFermion:sg2sStar
(default = off
)
Scatterings s g -> s^*.
Code 4003.
flag
ExcitedFermion:cg2cStar
(default = off
)
Scatterings c g -> c^*.
Code 4004.
flag
ExcitedFermion:bg2bStar
(default = off
)
Scatterings b g -> b^*.
Code 4005.
flag
ExcitedFermion:egm2eStar
(default = off
)
Scatterings e gamma -> e^*.
Code 4011.
flag
ExcitedFermion:mugm2muStar
(default = off
)
Scatterings mu gamma -> mu^*.
Code 4013.
flag
ExcitedFermion:taugm2tauStar
(default = off
)
Scatterings tau gamma -> tau^*.
Code 4015.
flag
ExcitedFermion:qq2dStarq
(default = off
)
Scatterings q q(bar) -> d^* q(bar).
Code 4021.
flag
ExcitedFermion:qq2uStarq
(default = off
)
Scatterings q q(bar) -> u^* q(bar).
Code 4022.
flag
ExcitedFermion:qq2sStarq
(default = off
)
Scatterings q q(bar) -> s^* q(bar).
Code 4023.
flag
ExcitedFermion:qq2cStarq
(default = off
)
Scatterings q q(bar) -> c^* q(bar).
Code 4024.
flag
ExcitedFermion:qq2bStarq
(default = off
)
Scatterings q q(bar) -> b^* q(bar).
Code 4025.
flag
ExcitedFermion:qqbar2eStare
(default = off
)
Scatterings q qbar -> e^*+- e^-+.
Code 4031.
flag
ExcitedFermion:qqbar2nueStarnue
(default = off
)
Scatterings q qbar -> nu_e^* nu_ebar.
Code 4032.
flag
ExcitedFermion:qqbar2muStarmu
(default = off
)
Scatterings q qbar -> mu^*+- mu^-+.
Code 4033.
flag
ExcitedFermion:qqbar2numuStarnumu
(default = off
)
Scatterings q qbar -> nu_mu^* nu_mubar.
Code 4034.
flag
ExcitedFermion:qqbar2tauStartau
(default = off
)
Scatterings q qbar -> tau^*+- tau^-+.
Code 4035.
flag
ExcitedFermion:qqbar2nutauStarnutau
(default = off
)
Scatterings q qbar -> nu_tau^* nu_taubar.
Code 4036.
Excited fermions, parameters
The basic couplings of the model are
parm
ExcitedFermion:Lambda
(default = 1000.
; minimum = 100.
)
Compositeness scale Lambda in GeV.
parm
ExcitedFermion:coupF
(default = 1.0
; minimum = 0.0
)
Strength f of the SU(2) coupling.
parm
ExcitedFermion:coupFprime
(default = 1.0
; minimum = 0.0
)
Strength f' of the U(1) coupling.
parm
ExcitedFermion:coupFcol
(default = 1.0
; minimum = 0.0
)
Strength f_c of the SU(3) coupling.
Contact interactions, production processes
The processes including contact interactions are
flag
ContactInteractions:QCqq2qq
(default = off
)
Scatterings q q -> q q including contact interactions.
Code 4201.
flag
ContactInteractions:QCqqbar2qqbar
(default = off
)
Scatterings q qbar -> q' qbar' including contact interactions.
Code 4202.
flag
ContactInteractions:QCffbar2eebar
(default = off
)
Scatterings f fbar -> e- e+ including contact interactions.
Code 4203.
flag
ContactInteractions:QCffbar2mumubar
(default = off
)
Scatterings f fbar -> mu- mu+ including contact interactions.
Code 4204.
flag
ContactInteractions:QCffbar2tautaubar
(default = off
)
Scatterings f fbar -> tau- tau+ including contact interactions.
Code 4205.
Contact interactions, parameters
mode
ContactInteractions:nQuarkNew
(default = 3
; minimum = 0
; maximum = 5
)
Number of allowed outgoing new quark flavours in the above
q qbar -> q' qbar' process. Similar to HardQCD:nQuarkNew
for the QCD processes.
parm
ContactInteractions:Lambda
(default = 1000.
; minimum = 100.
)
Compositeness scale Lambda in GeV.
mode
ContactInteractions:etaLL
(default = 0
; minimum = -1
; maximum = 1
)
Helicity parameter.
option
1 :
option
0 :
option
-1 :
mode
ContactInteractions:etaRR
(default = 0
; minimum = -1
; maximum = 1
)
Helicity parameter.
option
1 :
option
0 :
option
-1 :
mode
ContactInteractions:etaLR
(default = 0
; minimum = -1
; maximum = 1
)
Helicity parameter.
option
1 :
option
0 :
option
-1 :