Physics Letters B 764 (2017) 212–217
Contents lists available at ScienceDirect
Physics Letters B
www.elsevier.com/locate/physletb
Jost–Lehmann–Dyson representation in higher dimensional field
theories
Jnanadeva Maharana
Institute of Physics and NISER, Bhubaneswar, 751005, India
a r t i c l e i n f o a b s t r a c t
Article history:
Received
15 August 2016
Received
in revised form 26 October 2016
Accepted
28 October 2016
Available
online 23 November 2016
Editor: M.
Cveti
ˇ
c
The Jost–Lehmann–Dyson representation is derived for massive scalar field theories in higher spacetime
dimensions, D > 4, for the four point scattering amplitude. The representation is very crucial to
investigate the analyticity properties of the amplitude. The axiomatic approach of Lehmann–Symanzik–
Zimmermann
is adopted to show the existence of such a representation. Consequently, a host of
interesting results will follow from derivation of JLD representation such as proof of analyticity properties
and asymptotic behavior of the amplitude.
© 2016 Published by Elsevier B.V. This is an open access article under the CC BY license
(http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP
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.
The purpose of this letter is to derive the Jost–Lehmann–Dyson
(JLD) representation [1,2] for the four point scattering amplitude
of higher dimensional, D > 4, scalar, neutral, massive field theo-
ries.
It plays a central role in the investigation of the analyticity
properties of the amplitude as is elaborated in sequel. We work in
the Lehmann–Symanzik–Zimmermann (LSZ) [3] formalism of ax-
iomatic
field theory to derive the representation.
There
exist rigorous bounds on experimentally measurable pa-
rameter
in the context of four dimensional theories. These have
been derived from the study of the analyticity properties of scat-
tering
amplitudes. The most important attribute of these rigorous
results is that their derivations are based on the results proved
in the axiomatic field theoretic formalisms without resorting to
any specific model. Moreover, there are no observed experimen-
tal
violation of exacts results on total cross sections, width of
the diffraction peak in elastic scattering to mention a few. The
Froissart–Martin [4,5] bound on the total cross section, σ
t
, is the
most celebrated of all
σ
t
≤
4π
t
0
ln(
s
s
0
)
2
(1)
where t
0
=4m
2
π
for most of the hadronic processes; s is the center
of mass (c.m.) energy squared and s
0
is a scale introduced to make
the argument of the logarithm dimensionless. The crucial ingredi-
ents
leading to the derivation of the bound (1) are the unitarity
of S-matrix, crossing symmetry and analyticity of the amplitude
in s and t, the momentum transfer squared. The afore mentioned
results follow from the axiomatic field theoretic formalism [6–14].
E-mail address: maharana@iopb.res.in.
The analyticity of scattering amplitude in s and t facilitates writing
of the fixed t dispersion relation in s; t lying within the Lehmann
ellipse [15]. The partial wave expansion of the scattering amplitude
converges inside this ellipse.
The
role of the (JLD) representation is very fundamental in this
context. The proof of the existence of Lehmann ellipse rests on
the works of JLD. Moreover, the edge-of-the-wedge theorem [16]
is
proved by using this construction.
There
is growing consensus that theories in higher spacetime
dimensions, D > 4, are important to study fundamental interac-
tions
and geometric attributes of spacetime. There is increasing
interest to investigate properties of the scattering amplitude afresh
from various perspectives [18,19] in D > 4theories. The super-
symmetric
theories and supergravity theories have opened up the
possibilities to explore such theoretical constructions. Superstring
theories hold the promise of unifying the fundamental forces of
Nature. Moreover, the five perturbatively consistent string theories
live in D = 10. Of course, the standard model is defined in D = 4
and
its predictions have been experimentally tested with great ac-
curacy.
Thus the extra spatial dimensions of the D-dimensional
theories must be compactified. In the context of string theories,
most of the phenomenological analyses argue that the energy scale
of compactification is very high and therefore, the present acces-
sible
accelerators cannot reveal the existence of the compact extra
dimensions. However, in recent years elaborate models have been
constructed where the compactification scale is quite low i.e. the
presence of extra dimensions can be explored in LHC energy range.
There have been considerable phenomenological activities to ex-
amine
and propose the signatures for the spectra of new particles
[20,21]. Moreover, the present data does not rule out existence of
low compactification scales.
http://dx.doi.org/10.1016/j.physletb.2016.10.080
0370-2693/
© 2016 Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP
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.