TY  - JOUR
AU  - Amoroso, S.
AU  - Caron, S.
AU  - Jueid, A.
AU  - Ruiz de Austri, R.
AU  - Skands, P.
PY  - 2019
DA  - 2019//
TI  - Estimating QCD uncertainties in Monte Carlo event generators for gamma-ray dark matter searches
T2  - J. Cosmol. Astropart. Phys.
JO  - Journal of Cosmology and Astroparticle Physics
SP  - 007
EP  - 44pp
VL  - 05
IS  - 5
PB  - Iop Publishing Ltd
KW  - dark matter simulations
KW  - dark matter theory
KW  - gamma ray theory
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(*) -> qq-', 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.
SN  - 1475-7516
UR  - https://arxiv.org/abs/1812.07424
UR  - https://doi.org/10.1088/1475-7516/2019/05/007
DO  - 10.1088/1475-7516/2019/05/007
LA  - English
N1  - WOS:000467288200002
ID  - Amoroso_etal2019
ER  -