Inclusive-photon production and its dependence on photon isolation in $pp$ collisions at $\sqrt s=13$ TeV using 139 fb$^{-1}$ of ATLAS data

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abeling, Kira ; et al.
JHEP 07 (2023) 086, 2023.
Inspire Record 2628741 DOI 10.17182/hepdata.134100

Measurements of differential cross sections are presented for inclusive isolated-photon production in $pp$ collisions at a centre-of-mass energy of 13 TeV provided by the LHC and using 139 fb$^{-1}$ of data recorded by the ATLAS experiment. The cross sections are measured as functions of the photon transverse energy in different regions of photon pseudorapidity. The photons are required to be isolated by means of a fixed-cone method with two different cone radii. The dependence of the inclusive-photon production on the photon isolation is investigated by measuring the fiducial cross sections as functions of the isolation-cone radius and the ratios of the differential cross sections with different radii in different regions of photon pseudorapidity. The results presented in this paper constitute an improvement with respect to those published by ATLAS earlier: the measurements are provided for different isolation radii and with a more granular segmentation in photon pseudorapidity that can be exploited in improving the determination of the proton parton distribution functions. These improvements provide a more in-depth test of the theoretical predictions. Next-to-leading-order QCD predictions from JETPHOX and SHERPA and next-to-next-to-leading-order QCD predictions from NNLOJET are compared to the measurements, using several parameterisations of the proton parton distribution functions. The measured cross sections are well described by the fixed-order QCD predictions within the experimental and theoretical uncertainties in most of the investigated phase-space region.

48 data tables

Measured cross sections for inclusive isolated-photon production as a function of $E_{\rm T}^{\gamma}$ for $|\eta^{\gamma}|<0.6$ and photon isolation cone radius $R=0.4$.

Measured cross sections for inclusive isolated-photon production as a function of $E_{\rm T}^{\gamma}$ for $0.6<|\eta^{\gamma}|<0.8$ and photon isolation cone radius $R=0.4$.

Measured cross sections for inclusive isolated-photon production as a function of $E_{\rm T}^{\gamma}$ for $0.8<|\eta^{\gamma}|<1.37$ and photon isolation cone radius $R=0.4$.

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Measurement of the cross section for prompt isolated diphoton production using the full CDF Run II data sample

The CDF collaboration Aaltonen, T. ; Amerio, S. ; Amidei, D. ; et al.
Phys.Rev.Lett. 110 (2013) 101801, 2013.
Inspire Record 1207879 DOI 10.17182/hepdata.66020

This Letter reports a measurement of the cross section for producing pairs of central prompt isolated photons in proton-antiproton collisions at a total energy of 1.96 TeV using data corresponding to 9.5/fb integrated luminosity collected with the CDF II detector at the Fermilab Tevatron. The measured differential cross section is compared to three calculations derived from the theory of strong interactions. These include a prediction based on a leading order matrix element calculation merged with parton shower, a next-to-leading order, and a next-to-next-to-leading order calculation. The first and last calculations reproduce most aspects of the data, thus showing the importance of higher-order contributions for understanding the theory of strong interaction and improving measurements of the Higgs boson and searches for new phenomena in diphoton final states.

23 data tables

The measured differential cross sections for $M_{\gamma\gamma}$ , together with the predictions from the Sherpa and NNLO Monte Carlos.

The measured differential cross sections for $M_{\gamma\gamma}$ when $P_T > M_{\gamma\gamma}$ , together with the predictions from the Sherpa and NNLO Monte Carlos.

The measured differential cross sections for $M_{\gamma\gamma}$ when $P_T < M_{\gamma\gamma}$ , together with the predictions from the Sherpa and NNLO Monte Carlos.

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Direct Photon Production at the {CERN} {ISR}

The CMOR collaboration Angelis, A.L.S. ; Basini, G. ; Besch, H.J. ; et al.
Nucl.Phys.B 327 (1989) 541-568, 1989.
Inspire Record 279988 DOI 10.17182/hepdata.33181

A measurement of direct photon production in pp collisions at a center of mass energy ∝ s =63 GeV is reported. Arrays of lead-glass calorimeters and multiwire proportional chambers were used as photon detectors. Data are presented in the transverse momentum range from 4.5 to 10 GeV/ c and compared with QCD predictions. The event structure of this sample is compared with that of a set dominated by high transverse momentum π O ́ ' s .

3 data tables

Final Average Results from inside and outside detector.

Results for the inside detector.

Results for the outside detector.


Search for Direct Single Photon Production at Large p(T) in Proton Proton Collisions at s**(1/2) = 62.4-GeV

The CERN-Columbia-Oxford-Rockefeller & CCOR collaborations Angelis, A.L.S. ; Besch, H.J. ; Blumenfeld, Barry J. ; et al.
Phys.Lett.B 94 (1980) 106-112, 1980.
Inspire Record 153483 DOI 10.17182/hepdata.27178

As part of a study of large p T phenomena in photon-proton collisions at the CERN ISR, a search for direct single photon production has been performed. A statistical division of the data sample into the fraction consistent with single photon and the fraction due to multiphoton decays of neutral hadrons is accomplished by measuring the average conversion probability for the sample in a one radiation length thick converter. The fraction of the sample attributable to direct single photon production is 〈 γ /all〉 = 0.074 ± 0.012 for 6 GeV/ c < p T 10 GeV/ c , and 〈 γ /all〉 = 0.26 ± 0.04 for p T > 10 GeV/ c , with an additional systematic uncertainty of ±0.05 for both values.

1 data table

No description provided.