scholarly journals Discovery of higher-order quantum electrodynamics effect for the vacuum pair production

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
W. Zha ◽  
Z. Tang
Keyword(s):  
Pair Production ◽  
Quantum Electrodynamics ◽  
World Wide ◽  
Order Effect ◽  
Higher Order ◽  
Lepton Pair ◽  
Scientific Problem ◽  
Sigma Level ◽  
Level Of Significance ◽  
Important Milestone

Abstract The higher-order quantum electrodynamics (QED) effect for vacuum pair production has been searched without success since 1954. In this paper, we show that the combined world-wide data of lepton pair vacuum production is about 20% smaller than the latest lowest order QED calculation with a 5.2 sigma-level of significance and is consistent with the corresponding higher-order QED result. We claim the discovery of higher-order effect for the QED pair production, which settles the dust of previous debates for several decades. The verification of higher-order QED effect is a fundamental scientific problem, which is an important milestone towards the nonperturbative and nonlinear regime of QED vacuum.

scholarly journals Lepton-pair production in dipion τ lepton decays

2021 ◽  
Vol 103 (1) ◽  
Author(s):  
J. L. Gutiérrez Santiago ◽  
G. López Castro ◽  
P. Roig
Keyword(s):  
Pair Production ◽  
Lepton Pair ◽  
Lepton Pair Production ◽  
Lepton Decays

scholarly journals Global analysis of the Sivers functions at NLO+NNLL in QCD

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Miguel G. Echevarria ◽  
Zhong-Bo Kang ◽  
John Terry
Keyword(s):  
Pair Production ◽  
Global Analysis ◽  
Vector Boson ◽  
Lepton Pair ◽  
Transverse Spin ◽  
Dglap Evolution ◽  
Spin Asymmetries ◽  
Lepton Pair Production ◽  
Asymmetry Data ◽  
The Impact

Abstract We perform global fit to the quark Sivers function within the transverse momentum dependent (TMD) factorization formalism in QCD. We simultaneously fit Sivers asymmetry data from Semi-Inclusive Deep Inelastic Scattering (SIDIS) at COMPASS, HERMES, and JLab, from Drell-Yan lepton pair production at COMPASS, and from W/Z boson at RHIC. This extraction is performed at next-to-leading order (NLO) and next-to-next-to leading logarithmic (NNLL) accuracy. We find excellent agreement between our extracted asymmetry and the experimental data for SIDIS and Drell-Yan lepton pair production, while tension arises when trying to describe the spin asymmetries of W/Z bosons at RHIC. We carefully assess the situation, and we study in details the impact of the RHIC data and their implications through different ways of performing the fit. In addition, we find that the quality of the description of W/Z vector boson asymmetry data could be strongly sensitive to the DGLAP evolution of Qiu-Sterman function, besides the usual TMD evolution. We present discussion on this and the implications for measurements of the transverse-spin asymmetries at the future Electron Ion Collider.

scholarly journals Heavy lepton pair production in nucleus–nucleus collisions at LHC energy – a case study

2012 ◽  
Vol 889 ◽  
pp. 1-7
Author(s):  
Jan-e Alam ◽  
Bedangadas Mohanty ◽  
Sarbani Majumder ◽  
Sanjay K. Ghosh ◽  
Rajarshi Ray
Keyword(s):  
Pair Production ◽  
Lepton Pair ◽  
Heavy Lepton ◽  
Lepton Pair Production

scholarly journals Low-mass lepton-pair production in p-Be collisions at 450 GeV/c

1995 ◽  
Vol 68 (1) ◽  
pp. 47-64 ◽  
Author(s):  
T. Åkesson ◽  
S. Almehed ◽  
A. L. S. Angelis ◽  
J. Antos ◽  
H. Atherton ◽  
...  
Keyword(s):  
Pair Production ◽  
Lepton Pair ◽  
Lepton Pair Production ◽  
Low Mass

Lepton pair production in hadron-hadron collisions from an explicit parton model

1975 ◽  
Vol 92 (4) ◽  
pp. 413-426 ◽  
Author(s):  
G. Altarelli ◽  
N. Cabibbo ◽  
L. Maiani ◽  
R. Petronzio
Keyword(s):  
Pair Production ◽  
Parton Model ◽  
Lepton Pair ◽  
Lepton Pair Production
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