TY  - JOUR
AU  - Ali, Ahmed
AU  - Li, Gang
AU  - Wang, Wei
AU  - Xing, Zhi-Peng
TI  - Transverse energy–energy correlations of jets in the electron–proton deep inelastic scattering at HERA
JO  - The European physical journal / C
VL  - 80
IS  - 12
SN  - 1434-6052
CY  - Heidelberg
PB  - Springer
M1  - PUBDB-2021-01450
M1  - arXiv:2008.00271
M1  - ACFI-T20-09
M1  - DESY-20-129
SP  - 1096
PY  - 2020
N1  - 18 pages,11 figures; v2: 16 pages, accepted for publication in EPJC
AB  - We study the event shape variables, transverse energy–energy correlation TEEC (cosϕ) and its asymmetry ATEEC (cosϕ) in deep inelastic scattering (DIS) at the electron–proton collider HERA, where ϕ is the angle between two jets defined using a transverse-momentum (k<sub>T</sub>) jet algorithm. At HERA, jets are defined in the Breit frame, and the leading nontrivial transverse energy–energy correlations arise from the 3-jet configurations. With the help of the NLOJET++, these functions are calculated in the leading order (LO) and the next-to-leading order (NLO) approximations in QCD at the electron–proton center-of-mass energy √s=314 GeV. We restrict the angular region to −0.8  ≤ cosϕ ≤ 0.8, as the forward- and backward-angular regions require resummed logarithmic corrections, which we have neglected in this work. Following experimental jet-analysis at HERA, we restrict the DIS-variables x, y=Q<sup>2</sup>/(x s), where Q<sup>2</sup>=−q<sup>2</sup> is the negative of the momentum transfer squared q<sup>2</sup>, to 0  ≤ x  ≤ 1, 0.2  ≤ y  ≤ 0.6, and the pseudo-rapidity variable in the laboratory frame (η<sup>lab</sup>) to the range −1  ≤ η<sup>lab</sup>  ≤ 2.5. The TEEC and ATEEC functions are worked out for two ranges in Q<sup>2</sup>, defined by 5.5 GeV<sup>2</sup>  ≤ Q<sup>2</sup>  ≤ 80 GeV<sup>2</sup>, called the low-Q<sup>2</sup>-range, and 150 GeV<sup>2</sup>  ≤ Q<sup>2</sup>  ≤ 1000 GeV<sup>2</sup>, called the high-Q<sup>2</sup>-range. We show the sensitivity of these functions on the parton distribution functions (PDFs), the factorization (μ<sub>F</sub>) and renormalization (μ<sub>R</sub>) scales, and on α<sub>s</sub>(M<sub>Z</sub><sup>2</sup>). Of these the correlations are stable against varying the scale μ<sub>F</sub> and the PDFs, but they do depend on μ<sub>R</sub>. For the choice of the scale μ<sub>R</sub> = √{〈E<sub>T</sub>〉<sup>2</sup> +Q<sup>2</sup>}, advocated in earlier jet analysis at HERA, the shape variables TEEC and ATEEC are found perturbatively robust. These studies are useful in the analysis of the HERA data, including the determination of α<sub>s</sub>(M<sub>Z</sub><sup>2</sup>) from the shape variables.
KW  - parton: distribution function (INSPIRE)
KW  - jet: production (INSPIRE)
KW  - transverse energy (INSPIRE)
KW  - correlation (INSPIRE)
KW  - electron p: deep inelastic scattering (INSPIRE)
KW  - higher-order: 0 (INSPIRE)
KW  - higher-order: 1 (INSPIRE)
KW  - DESY HERA Stor (INSPIRE)
KW  - quantum chromodynamics (INSPIRE)
KW  - event shape analysis (INSPIRE)
KW  - scale: renormalization (INSPIRE)
KW  - factorization (INSPIRE)
KW  - Breit frame (INSPIRE)
KW  - stability (INSPIRE)
KW  - asymmetry (INSPIRE)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000596503400002
DO  - DOI:10.1140/epjc/s10052-020-08614-3
UR  - https://bib-pubdb1.desy.de/record/456314
ER  -