The University of Southampton
University of Southampton Institutional Repository

Photon-initiated production of a dilepton final state at the LHC: Cross section versus forward-backward asymmetry studies

Photon-initiated production of a dilepton final state at the LHC: Cross section versus forward-backward asymmetry studies
Photon-initiated production of a dilepton final state at the LHC: Cross section versus forward-backward asymmetry studies
We explore the effects of Photon Induced (PI) production of a dilepton final state in the Large Hadron Collider environment. Using QED Parton Distribution Function (PDF) sets we can treat the photons as real partons inside the protons and compare their yield directly to that of the Drell-Yan (DY) process. In particular, we concentrate on an error analysis of the two mechanisms. In order to do so, we use the NNPDF set, which comes with a set of replicas to estimate the systematic PDF error. On the one hand, we find that the PI contribution becomes dominant over DY above a dilepton invariant mass of 3 TeV. On the other hand, the PI predictions are affected by a large error coming from the QED PDFs, well above the one affecting the DY mode. We assess the impact of these uncertainties in the context of resonant and non-resonant searches for a neutral massive vector boson (Z') through the differential cross section and Forward-Backward Asymmetry (AFB) observables as a function of the dilepton invariant mass. While the former is subject to the aforementioned significant residual errors the latter shows the systematic error cancellation expected (recall that AFB is a ratio of cross sections) even in presence of PI contributions, so that the recently emphasized key role played by AFB as a valid tool for both Z' discovery and interpretation in both resonant and non-resonant mode is further consolidated.
2470-0010
Accomando, Elena
8ebc75d7-bd92-4f70-a974-7bc15ebf088f
Fiaschi, Juri
a417f04d-05ec-4bff-bdee-ba20ac560fa7
Hautmann, Francesco
226fd98a-070e-478e-a02e-42a918dca6c0
Moretti, Stefano
b57cf0f0-4bc3-4e02-96e3-071255366614
Shepherd-themistocleous, Claire H.
02e9b880-a622-4ad1-9b20-db7ed25b2fa8
Accomando, Elena
8ebc75d7-bd92-4f70-a974-7bc15ebf088f
Fiaschi, Juri
a417f04d-05ec-4bff-bdee-ba20ac560fa7
Hautmann, Francesco
226fd98a-070e-478e-a02e-42a918dca6c0
Moretti, Stefano
b57cf0f0-4bc3-4e02-96e3-071255366614
Shepherd-themistocleous, Claire H.
02e9b880-a622-4ad1-9b20-db7ed25b2fa8

Accomando, Elena, Fiaschi, Juri, Hautmann, Francesco, Moretti, Stefano and Shepherd-themistocleous, Claire H. (2017) Photon-initiated production of a dilepton final state at the LHC: Cross section versus forward-backward asymmetry studies Physical Review D, 95, (3) (doi:10.1103/PhysRevD.95.035014).

Record type: Article

Abstract

We explore the effects of Photon Induced (PI) production of a dilepton final state in the Large Hadron Collider environment. Using QED Parton Distribution Function (PDF) sets we can treat the photons as real partons inside the protons and compare their yield directly to that of the Drell-Yan (DY) process. In particular, we concentrate on an error analysis of the two mechanisms. In order to do so, we use the NNPDF set, which comes with a set of replicas to estimate the systematic PDF error. On the one hand, we find that the PI contribution becomes dominant over DY above a dilepton invariant mass of 3 TeV. On the other hand, the PI predictions are affected by a large error coming from the QED PDFs, well above the one affecting the DY mode. We assess the impact of these uncertainties in the context of resonant and non-resonant searches for a neutral massive vector boson (Z') through the differential cross section and Forward-Backward Asymmetry (AFB) observables as a function of the dilepton invariant mass. While the former is subject to the aforementioned significant residual errors the latter shows the systematic error cancellation expected (recall that AFB is a ratio of cross sections) even in presence of PI contributions, so that the recently emphasized key role played by AFB as a valid tool for both Z' discovery and interpretation in both resonant and non-resonant mode is further consolidated.

Text 1606.06646 - Accepted Manuscript
Download (1MB)

More information

Accepted/In Press date: 21 June 2016
e-pub ahead of print date: 14 February 2017
Published date: 14 February 2017
Additional Information: Accepted mss available at arXiv:1606.06646 since 27 January 2017
Organisations: Physics & Astronomy, Theory Group

Identifiers

Local EPrints ID: 409628
URI: http://eprints.soton.ac.uk/id/eprint/409628
ISSN: 2470-0010
PURE UUID: 6ebf0a62-dafa-44fb-92ad-0a8a2a728e5b

Catalogue record

Date deposited: 01 Jun 2017 04:04
Last modified: 20 Nov 2017 17:31

Export record

Altmetrics

Contributors

Author: Elena Accomando
Author: Juri Fiaschi
Author: Francesco Hautmann
Author: Stefano Moretti
Author: Claire H. Shepherd-themistocleous

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×