scikit-hep/iminuit: v1.5.4

Dembinski, H.-P.; Ongmongkolkul, P.; Deil, C.; Hurtado, David Ménendez; Schreiner, Henry; Feickert, M.; Andrew, Andrew; Burr, C.; Rost, Fabian; Pearce, A.; Geiger, Lukas; Wiedemann, Bernhard M.; Gonzalo,; Gorelli, Marco; Zapata, Óscar

doi:10.5281/zenodo.4283509

Cited by 3 publications

(1 citation statement)

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“…The results of the fit are presented in figure 10, and the model parameters, both the true generated values and the values obtained from the fit, are given in table 3. The maximum likelihood fit is performed using iminuit [44], and the interface between the ANN implemented in TensorFlow and iminuit is provided by TensorFlowAnalysis package [39].…”

Section: Jinst 16 P06016mentioning

confidence: 99%

Efficient description of experimental effects in amplitude analyses

Mathad¹,

O’Hanlon²,

Poluektov³

et al. 2021

J. Inst.

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Amplitude analysis is a powerful technique to study hadron decays. A significant complication in these analyses is the treatment of instrumental effects, such as background and selection efficiency variations, in the multidimensional kinematic phase space. This paper reviews conventional methods to estimate efficiency and background distributions and outlines the methods of density estimation using Gaussian processes and artificial neural networks. Such techniques see widespread use elsewhere, but have not gained popularity in use for amplitude analyses. Finally, novel applications of these models are proposed, to estimate background density in the signal region from the sidebands in multiple dimensions, and a more general method for model-assisted density estimation using artificial neural networks.

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Section: Jinst 16 P06016mentioning

confidence: 99%

Efficient description of experimental effects in amplitude analyses

Mathad¹,

O’Hanlon²,

Poluektov³

et al. 2021

J. Inst.

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Search for Line-like and Box-shaped Spectral Features from Nearby Galaxy Clusters with 11.4 Years of Fermi Large Area Telescope Data

Shen¹,

Xia²,

Fan

2021

ApJ

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Sharp spectral structures in the γ-ray band are an important dark matter (DM) signature. Previously, a tentative line feature at ∼43 GeV was reported in 16 nearby galaxy clusters (GCls) with 7.1 yr of Fermi Large Area Telescope (LAT) data, whose test statistic (TS) value is ∼16.7. In this work, we search for line signals and box-shaped structures using the stacked data from those 16 GCls with 11.4 yr of Fermi-LAT P8R3 data. There is still a hint at ∼42 GeV, dominated by the radiation of the Virgo and Ophiuchus clusters. Though the TS value was high up to 21.2 in 2016 October, currently it has dropped to 13.1. Moreover, the TS value at ∼42 GeV decreases to 2.4 when the EDISP2 data are excluded from the analysis. Consequently, we do not find any statistically significant line-like signal and then set up the 95% confidence level upper limits on the thermally averaged cross section of DM annihilating into double photons. The same line search has been carried out for an alternative GCl sample from the Two Micron All-Sky Survey, but no evidence has been found. We also search for box-shaped features in those 16 baseline GCls. No signal is found, and the corresponding upper limits on the annihilation cross section are given.

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The Calibrations of the DAMPE γ-Ray Effective Area

Shen,

Li,

Duan

et al. 2024

ApJ

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The Dark Matter Particle Explorer (DAMPE) is a cosmic-ray detector as well as a pair-converting γ-ray telescope. The effective area, reflecting the geometrical cross-section area, the γ-ray conversion probability, and the photon selection efficiency, is important in γ-ray analyses. In this work, we find a significant time variation in the effective area, as large as ∼−4% yr−1 at 2 GeV for the high-energy trigger. We derive the data-based correction factors to the effective areas and apply corrections to both the effective areas and the exposure maps. The calibrated exposure can be ∼12% smaller than the Monte Carlo one on average at 2 GeV. The calibration is further verified using the observation of the Vela pulsar, showing the spectral parameters with the correction are more consistent with those in the Fermi-LAT catalog than the ones without correction. All the corrections are now implemented in the latest version of the DAMPE γ-ray analysis toolkit DmpST.

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scikit-hep/iminuit: v1.5.4

Cited by 3 publications

References 0 publications

Efficient description of experimental effects in amplitude analyses

Efficient description of experimental effects in amplitude analyses

Search for Line-like and Box-shaped Spectral Features from Nearby Galaxy Clusters with 11.4 Years of Fermi Large Area Telescope Data

The Calibrations of the DAMPE γ-Ray Effective Area

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