Research Article
Searches for Massive Graviton Resonances at the LHC
T. V. Obikhod andI.A.Petrenko
InstituteforNuclearResearch,NationalAcademyofSciencesofUkraine,47Prosp.Nauki,Kiev03028,Ukraine
Correspondence should be addressed to T. V. Obikhod; obikhod@kinr.kiev.ua
Received 17 January 2018; Accepted 21 February 2018; Published 30 April 2018
A
c
ademic Editor: Marek Nowakowski
Copyright © T. V. Obikhod and I. A. Petrenko. 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
.
e Standard Model problems lead to the new theories of extra dimensions: Randall-Sundrum model, Arkani-Hamed-
Dimopoulos-Dvali model, and TeV
−1
model. In the framework of these models, with the help of computer program Pythia.,
the production cross sections for Kaluza-Klein particles at various energies at the LHC were calculated. e generation of monojet
events from scalar graviton emission was considered for number of extra dimensions (=2,,and)fortheenergyattheLHC
TeV. e graviton production processes through the gluon-gluon, quark-gluon, and quark-quark fusion processes are also studied
and some periodicity was found in the behavior of the graviton mass spectrum. Production cross sections multiplied by branching
fractions were calculated for the massive graviton, G, within Randall-Sundrum scenario and the most probable processes of graviton
decay at TeV, TeV, and TeV were counted.
1. Introduction
e problems with theoretical explanation of vacuum energy
as well as dark energy, dark matter, and cosmological constant
problems are only the tip of the iceberg of problems in the
modern theoretical physics. Some of them are
(i) ordinary matter accounting for about % of mass
energy in the Universe and no dark matter candidate
in the Standard Model (SM),
(ii) hierarchy problem,
(iii) ne tuning of SM Higgs mass,
(iv) no explanation for fermion masses and mixings and
three family structures,
(v) unication of strong, electroweak, and gravitational
forces,
(vi) compositeness of leptons and quarks,
It is an experimental fact that there is something we cannot
explain within the SM.
As is known, vacuum is produced in the processes of
phase transitions in Early Universe and the space-time struc-
ture of the physical vacuum exhibits the connection to the
structure formation in our Universe. So, the understanding of
Universe formation is deeply connected with the conception
of the space-time. According to hierarchy formula [], Plank
energy can be reduced to the energy of about TeV that
is achieved at the LHC. So, the phenomena of the Universe
formation at the early stages and the accompanying processes
of particle physics could be studied at modern colliders.
In spite of the fact that no new physics beyond the SM is
discovered at the LHC at TeV, the planned upgrading of
theLHCtohighluminositiesandenergiesuptoTeV
gives the possibility for the discovery of new physics. Among
such searches for new physics, the most popular are the
experimental searches for the Kaluza-Klein (KK) particles.
Historically, KK theory appeared as the unication of
gravitational and electromagnetic interactions due to the
proposition of a h dimension in addition to the usual
four-dimensional space-time [–], which leads to the con-
sideration of the concept of deformation of Riemannian
geometry dened by extrinsic curvature of the space-time.
e conclusions of this result are based, in particular, on the
ve-dimensional space from the paper []. Arkani-Hamed et
al. proposed the solution to the hierarchy problem on the
basis of the existence of new compact spatial dimensions.
KK excitations in this extra dimensional space through the
combined eect of all the gravitons became observable.
Hindawi
Advances in High Energy Physics
Volume 2018, Article ID 3471023, 9 pages
https://doi.org/10.1155/2018/3471023