Photon Cascade Decay of the Warped Graviton at LHC14 and a 100 TeV Hadron Collider

Abstract

In warped 5D models of hierarchy and flavor, the first Kaluza-Klein (KK) state of the graviton $G_1$ is heavy enough to decay into a photon and its first KK mode ${\gamma }_1$ on-shell: $G_1\to {\gamma }_1\gamma$. The volume-suppression of the rate for this process [relative to 2-body decay into heavy Standard Model (SM) final states ($W/Z/t/H$)] may be partially compensated by the simplicity of the photon final state. We consider ${\gamma }_1\to W^{+}{W}^{-}$, with a typical O(1) branching fraction, and focus on the semi-leptonic final state $W(\to jj)W(\to \ell ,\nu )$ with $\ell =e,\mu$. The SM background originates from $2\to 3$ parton processes and is relatively suppressed compared to those for 2-body decays of $G_1$. Moreover, to further reduce the background, we can impose an invariant mass window cut for ${\gamma }_1$ (in addition to that for $G_1$) in this new channel. We emphasize that this "photon cascade" decay probes a different combination of (bulk and brane) interactions of the KK states than the decays into two heavy SM states. Thus, in combination with other channels, the cascade decay could be used to extract the individual underlying geometric parameters. The $3\sigma$ reach for $G_1$ in our channel is up to 1.5 TeV at the high luminosity (14 TeV) LHC, and can be extended to about 4 TeV, at $5\sigma$, at a future 100 TeV hadron collider. Along the way, we point out the novel feature that the invariant mass distribution of KK graviton decay products becomes skewed from the Breit-Wigner form, due to the KK graviton coupling growing with energy.

arXiv comment25 pages, 5 figures and 2 tables, various editorial changes, references added, physics results and conclusions unchanged

References in corpus (53)

• Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC
• Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
• A Large Mass Hierarchy from a Small Extra Dimension
• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• Parton distributions with LHC data
• Modulus Stabilization with Bulk Fields
• Bulk Fields and Supersymmetry in a Slice of AdS
• CalcHEP 3.4 for collider physics within and beyond the Standard Model
• Neutrino masses and mixings in non-factorizable geometry
• Quantum Gravity and Extra Dimensions at High-Energy Colliders
• On Kaluza-Klein States from Large Extra Dimensions
• A custodial symmetry for Zbb
• RS1, Custodial Isospin and Precision Tests
• Bulk Gauge Fields in the Randall-Sundrum Model
• Flavor Structure of Warped Extra Dimension Models
• Warped Phenomenology
• Fermion Masses, Mixings and Proton Decay in a Randall-Sundrum Model
• Phenomenology of a Stabilized Modulus
• Experimental Probes of Localized Gravity: On and Off the Wall
• Gauge bosons in a five-dimensional theory with localized gravity
• The Flavor of the Composite Pseudo-Goldstone Higgs
• Bulk Fields in the Randall-Sundrum Compactification Scenario
• Flavor violation and warped geometry
• LHC Signals from Warped Extra Dimensions
• Warped Gravitons at the LHC and Beyond
• The Bulk RS KK-gluon at the LHC
• Light Kaluza-Klein States in Randall-Sundrum Models with Custodial SU(2)
• Delta F=2 Observables and Fine-Tuning in a Warped Extra Dimension with Custodial Protection
• Electroweak constraints on warped models with custodial symmetry
• LHC Signals for Warped Electroweak Neutral Gauge Bosons
• Searching for the Kaluza-Klein Graviton in Bulk RS Models
• Search for massive resonances decaying into pairs of boosted bosons in semi-leptonic final states at sqrt(s) = 8 TeV
• On Partial Compositeness and the CP asymmetry in charm decays
• Flavor Physics in the Randall-Sundrum Model: II. Tree-Level Weak-Interaction Processes
• Searches for new physics using the ttbar invariant mass distribution in pp collisions at sqrt(s)=8 TeV
• LHC Signals for Warped Electroweak Charged Gauge Bosons
• Kaluza--Klein excitations of gauge bosons at the LHC
• Graviton Cosmology in Universal Extra Dimensions
• Warped 5-Dimensional Models: Phenomenological Status and Experimental Prospects
• A 125 GeV composite Higgs boson versus flavour and electroweak precision tests
• Kaluza-Klein Gluons as a Diagnostic of Warped Models
• Collider Phenomenology of Gauge-Higgs Unification Scenarios in Warped Extra Dimensions
• Anatomy of flavour-changing Z couplings in models with partial compositeness
• Ultra Visible Warped Model From Flavor Triviality & Improved Naturalness
• Hunting composite vector resonances at the LHC: naturalness facing data
• Single Vectorlike Quark Production at the LHC
• Heavy-light decay topologies as a new strategy to discover a heavy gluon
• Search for RS gravitons via $W_L{W}_L$ decays
• Dipole operator constraints on composite Higgs models
• The Elusive Gluon
• New W-prime signals at the LHC
• Warped Graviton "Z + Missing Energy" Signal at Hadron Colliders
• Gravity and Matter in Extra Dimensions

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