1 <chapter name="Extra-Dimensional Processes">
3 <h2>Extra-Dimensional Processes</h2>
5 Scenarios with extra dimensions allow a multitude of processes.
6 Currently the only ones implemented involve the production of an
7 excited graviton state <ei>G^*</ei> within a Randall-Sundrum scenario.
8 This state is assigned PDG code 5000039. Decays into fermion, gluon
9 and photon pairs are handled with the correct angular distributions,
10 while other decay channels currently are handled isotropically.
12 <h3>Production processes</h3>
14 There are two lowest-order processes that together normally should be
15 sufficient for a simulation of <ei>G^*</ei> production.
17 <flag name="ExtraDimensionsG*:all" default="off">
18 Common switch for the group of lowest-order <ei>G^*</ei> production
19 processes, i.e. the two ones below.
22 <flag name="ExtraDimensionsG*:gg2G*" default="off">
23 Scatterings <ei>g g -> G^*</ei>.
27 <flag name="ExtraDimensionsG*:ffbar2G*" default="off">
28 Scatterings <ei>f fbar -> G^*</ei>.
33 In addition there are three first-order processes included. These are of
34 less interest, but can be used for dedicated studies of the high-<ei>pT</ei>
35 tail of <ei>G^*</ei> producton. As usual, it would be doublecounting to
36 include the lowest-order and first-order processes simultaneously.
37 Therefore the latter ones are not included with the
38 <code>ExtraDimensionsG*:all = on</code> option. In this set of processes
39 all decay angles are assumed istropic.
41 <flag name="ExtraDimensionsG*:gg2G*g" default="off">
42 Scatterings <ei>g g -> G^* g</ei>.
46 <flag name="ExtraDimensionsG*:qg2G*q" default="off">
47 Scatterings <ei>q g -> G^* q</ei>.
51 <flag name="ExtraDimensionsG*:qqbar2G*g" default="off">
52 Scatterings <ei>q qbar -> G^* g</ei>.
59 In the above scenario the main free parameter is the <ei>G^*</ei> mass,
60 which is set as usual. In addition there is one further parameter.
62 <parm name="ExtraDimensionsG*:kappaMG" default="0.054" min="0.0">
63 dimensionless coupling, which enters quadratically in all partial
64 widths of the <ei>G^*</ei>. Is
65 <ei>kappa m_G* = sqrt(2) x_1 k / Mbar_Pl</ei>,
66 where <ei>x_1 = 3.83</ei> is the first zero of the <ei>J_1</ei> Bessel
67 function and <ei>Mbar_Pl</ei> is the modified Planck mass.
72 <!-- Copyright (C) 2008 Torbjorn Sjostrand -->