Research Article
Mass of the Stabilized Radion in the Limit of
Finite Quartic Coupling
Ali Tofighi
1
and Vahid Reza Shajiee
2
1
Department of Physics, Faculty of Basic Science, University of Mazandaran, P.O. Box 47416-95447, Babolsar, Iran
2
Young Researchers and Elite Club, Mashhad Branch, Islamic Azad University, Mashhad, Iran
Correspondence should be addressed to Vahid Reza Shajiee; v.shajiee@mshdiau.ac.ir
Received 28 September 2016; Revised 6 February 2017; Accepted 1 March 2017; Published 12 March 2017
Ac
ademic Editor: Edward Sarkisyan-Grinbaum
Copyright © 2017 Ali Toghi and Vahid Reza Shajiee. is is an open access article distributed under the Creative Commons
Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is
properly cited. e publication of this article was funded by SCOAP
3
.
We present an exact treatment of the modulus stabilization condition with the general boundary conditions of the bulk scalar eld
in the Randall-Sundrum model. We nd analytical expressions for the value of the modulus and the mass of the radion.
1. Introduction
e hierarchy problem is one of the most attractive open
problems in the modern physics. Roughly speaking, the prob-
lem is the large discrepancy between the weak and the Planck
scale. e problem was addressed by several theories, like
supersymmetry, and higher dimensional theories; however, it
has remained unsolved in the literature. rough the eorts
in this direction, an impressive work is Randall-Sundrum
(RS) model [1] which introduces a small extra dimension.
e model has two branes which are called “Planck” and
“TeV” branes; also it is assumed that a slice of AdS
5
spacetime
exists between the branes. A ve-dimensional solution to the
Einstein eld equations in RS model is given by
2
=
−2𝑘𝑟
𝑐
|𝜙|
𝜇]
𝜇
]
−
2
𝑐
2
,
(1)
where −≤≤is the extra dimension coordinate,
the coecient
𝑐
is the compactication radius, and the
parameter is related to the 5-D Planck mass, .
It would be interesting to check out the stability of the
extra dimension, , in the RS model. Such an investigation
was addressed by Goldberger and Wise (GW) [2]. e GW
model contains a massive scalar eld with usual kinetic term
in the bulk and quartic interactions localized on the branes.
e original work of [2] has several deciencies, namely:
(1)ebulkmasstermbreakstheconformalinvariance
of the theory.
(2) In the limit of innite quartic coupling considered in
[2], it is not possible to unravel the complete structure
of the critical points of the theory; hence they miss the
source of instability as indicated by the existence of a
closely spaced maximum.
(3) e boundary conditions of the model are comprised
ofapairofcoupledcubicalgebraicequations.In[2]
these boundary conditions are not solved; instead
they merely choose a specic conguration.
(4) In addition they only consider the leading order term
in their calculations. Hence their treatment of the
subject matter is an approximate one.
erefore, many studies were done on this subject [3–12].
In [3–5], the authors have considered the stabilization of
the modulus containing a scalar eld, which interacts with
the spacetime curvature ,inthebulk.esetheorieshave
conformal invariance at certain value of the coupling constant
of the curvature and the scalar eld; hence they remedy
objection 1, raised above.
An exact analysis of the GW mechanism has been
discussed in [6] and the objections 2–4 have been addressed.
However their treatment of the stabilized modulus is a
numerical one. ey also do not address the issue of the
mass of radion at nite values of the quartic coupling
constant.eissueofGoldberger-Wisemechanismwith
the general boundary conditions also has been discussed in
Hindawi
Advances in High Energy Physics
Volume 2017, Article ID 1213670, 6 pages
https://doi.org/10.1155/2017/1213670