Estimating QCD uncertainties in Monte Carlo event generators for gamma-ray dark matter searches

Simone Amoroso, Sascha Caron, Adil Jueid, Roberto Ruiz De Austri, Peter Skands

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Motivated by the recent galactic center gamma-ray excess identified in the Fermi-LAT data, we perform a detailed study of QCD fragmentation uncertainties in the modeling of the energy spectra of gamma-rays from Dark-Matter (DM) annihilation. When Dark-Matter particles annihilate to coloured final states, either directly or via decays such as W(∗) q′, photons are produced from a complex sequence of shower, hadronisation and hadron decays. In phenomenological studies their energy spectra are typically computed using Monte Carlo event generators. These results have however intrinsic uncertainties due to the specific model used and the choice of model parameters, which are difficult to asses and which are typically neglected. We derive a new set of hadronisation parameters (tunes) for the PYTHIA 8.2 Monte Carlo generator from a fit to LEP and SLD data at the Z peak. For the first time we also derive a conservative set of uncertainties on the shower and hadronisation model parameters. Their impact on the gamma-ray energy spectra is evaluated and discussed for a range of DM masses and annihilation channels. The spectra and their uncertainties are also provided in tabulated form for future use. The fragmentation-parameter uncertainties may be useful for collider studies as well.

Original languageEnglish
Article number007
Number of pages45
JournalJournal of Cosmology and Astroparticle Physics
Volume2019
Issue number5
DOIs
Publication statusPublished - 7 May 2019

Keywords

  • dark matter simulations
  • dark matter theory
  • gamma ray theory

Cite this

Amoroso, Simone ; Caron, Sascha ; Jueid, Adil ; De Austri, Roberto Ruiz ; Skands, Peter. / Estimating QCD uncertainties in Monte Carlo event generators for gamma-ray dark matter searches. In: Journal of Cosmology and Astroparticle Physics. 2019 ; Vol. 2019, No. 5.
@article{c08a5b3d900a41928b311bd634cc2371,
title = "Estimating QCD uncertainties in Monte Carlo event generators for gamma-ray dark matter searches",
abstract = "Motivated by the recent galactic center gamma-ray excess identified in the Fermi-LAT data, we perform a detailed study of QCD fragmentation uncertainties in the modeling of the energy spectra of gamma-rays from Dark-Matter (DM) annihilation. When Dark-Matter particles annihilate to coloured final states, either directly or via decays such as W(∗) q′, photons are produced from a complex sequence of shower, hadronisation and hadron decays. In phenomenological studies their energy spectra are typically computed using Monte Carlo event generators. These results have however intrinsic uncertainties due to the specific model used and the choice of model parameters, which are difficult to asses and which are typically neglected. We derive a new set of hadronisation parameters (tunes) for the PYTHIA 8.2 Monte Carlo generator from a fit to LEP and SLD data at the Z peak. For the first time we also derive a conservative set of uncertainties on the shower and hadronisation model parameters. Their impact on the gamma-ray energy spectra is evaluated and discussed for a range of DM masses and annihilation channels. The spectra and their uncertainties are also provided in tabulated form for future use. The fragmentation-parameter uncertainties may be useful for collider studies as well.",
keywords = "dark matter simulations, dark matter theory, gamma ray theory",
author = "Simone Amoroso and Sascha Caron and Adil Jueid and {De Austri}, {Roberto Ruiz} and Peter Skands",
year = "2019",
month = "5",
day = "7",
doi = "10.1088/1475-7516/2019/05/007",
language = "English",
volume = "2019",
journal = "Journal of Cosmology and Astroparticle Physics",
issn = "1475-7516",
publisher = "IOP Publishing",
number = "5",

}

Estimating QCD uncertainties in Monte Carlo event generators for gamma-ray dark matter searches. / Amoroso, Simone; Caron, Sascha; Jueid, Adil; De Austri, Roberto Ruiz; Skands, Peter.

In: Journal of Cosmology and Astroparticle Physics, Vol. 2019, No. 5, 007, 07.05.2019.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Estimating QCD uncertainties in Monte Carlo event generators for gamma-ray dark matter searches

AU - Amoroso, Simone

AU - Caron, Sascha

AU - Jueid, Adil

AU - De Austri, Roberto Ruiz

AU - Skands, Peter

PY - 2019/5/7

Y1 - 2019/5/7

N2 - Motivated by the recent galactic center gamma-ray excess identified in the Fermi-LAT data, we perform a detailed study of QCD fragmentation uncertainties in the modeling of the energy spectra of gamma-rays from Dark-Matter (DM) annihilation. When Dark-Matter particles annihilate to coloured final states, either directly or via decays such as W(∗) q′, photons are produced from a complex sequence of shower, hadronisation and hadron decays. In phenomenological studies their energy spectra are typically computed using Monte Carlo event generators. These results have however intrinsic uncertainties due to the specific model used and the choice of model parameters, which are difficult to asses and which are typically neglected. We derive a new set of hadronisation parameters (tunes) for the PYTHIA 8.2 Monte Carlo generator from a fit to LEP and SLD data at the Z peak. For the first time we also derive a conservative set of uncertainties on the shower and hadronisation model parameters. Their impact on the gamma-ray energy spectra is evaluated and discussed for a range of DM masses and annihilation channels. The spectra and their uncertainties are also provided in tabulated form for future use. The fragmentation-parameter uncertainties may be useful for collider studies as well.

AB - Motivated by the recent galactic center gamma-ray excess identified in the Fermi-LAT data, we perform a detailed study of QCD fragmentation uncertainties in the modeling of the energy spectra of gamma-rays from Dark-Matter (DM) annihilation. When Dark-Matter particles annihilate to coloured final states, either directly or via decays such as W(∗) q′, photons are produced from a complex sequence of shower, hadronisation and hadron decays. In phenomenological studies their energy spectra are typically computed using Monte Carlo event generators. These results have however intrinsic uncertainties due to the specific model used and the choice of model parameters, which are difficult to asses and which are typically neglected. We derive a new set of hadronisation parameters (tunes) for the PYTHIA 8.2 Monte Carlo generator from a fit to LEP and SLD data at the Z peak. For the first time we also derive a conservative set of uncertainties on the shower and hadronisation model parameters. Their impact on the gamma-ray energy spectra is evaluated and discussed for a range of DM masses and annihilation channels. The spectra and their uncertainties are also provided in tabulated form for future use. The fragmentation-parameter uncertainties may be useful for collider studies as well.

KW - dark matter simulations

KW - dark matter theory

KW - gamma ray theory

UR - http://www.scopus.com/inward/record.url?scp=85069739750&partnerID=8YFLogxK

U2 - 10.1088/1475-7516/2019/05/007

DO - 10.1088/1475-7516/2019/05/007

M3 - Article

VL - 2019

JO - Journal of Cosmology and Astroparticle Physics

JF - Journal of Cosmology and Astroparticle Physics

SN - 1475-7516

IS - 5

M1 - 007

ER -