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 quarks is also implemented in the context
of 2 -> 2 quark 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. In additions to the compositness scale and couplings listed
below, you are expected to change the excited-fermion masses in accordance
with what is desired. See [Bau90] for conventions.
A non-trivial angular dependence is included in the decay for the
2 -> 1 processes, but has not been included for the
2 -> 2 ones.
The quark contact interactions are implemented according to
[Eic83]. The processes include the QCD contributions
as well as interference. For this reason the two processes
below converge toward, HardQCD:qq2qq
and
HardQCD:qqbar2qqbarNew
, when the contact interaction
contributions are close to zero.
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 quark 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.
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 :