Electron propagator in a strong electromagnetic field in the very-high-energy limit

1990 ◽  
Vol 42 (11) ◽  
pp. 3870-3874 ◽  
Author(s):  
Krzysztof Kurek
1970 ◽  
Vol 2 (3) ◽  
pp. 572-577 ◽  
Author(s):  
A. O. Barut ◽  
W. Plywaski

2019 ◽  
Vol 208 ◽  
pp. 11001 ◽  
Author(s):  
Sergey Ostapchenko

We discuss in some detail the physics content of the new model, QGSJET-III-01, focusing on major problems related to the treatment of semihard processes in the very high energy limit. A special attention has been payed to the main improvement, compared to the QGSJET-II model, which is related to a phenomenological treatment of leading power corrections corresponding to final parton rescattering off soft gluons. In particular, this allowed us to use a twice smaller separation scale between the soft and hard parton physics, compared to the previous model version, QGSJET-II-04. Preliminary results obtained with the new model are also presented.


1996 ◽  
Vol 11 (34) ◽  
pp. 2681-2692 ◽  
Author(s):  
DING-WEI HUANG

We show that four different approaches in multiple production give exactly the same multiplicity distribution. Various experimental data can be well described by this new multiplicity distribution. We compare this new distribution to the negative binomial distribution. The restoration of KNO scaling at the very high energy limit is discussed. A nonvanishing value of the scaled multiplicity distribution Ψ(z) at z=0 is predicted.


2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Peter Arnold ◽  
Tyler Gorda ◽  
Shahin Iqbal

Abstract The splitting processes of bremsstrahlung and pair production in a medium are coherent over large distances in the very high energy limit, which leads to a suppression known as the Landau-Pomeranchuk-Migdal (LPM) effect. We continue study of the case when the coherence lengths of two consecutive splitting processes overlap (which is important for understanding corrections to standard treatments of the LPM effect in QCD), avoiding soft-emission approximations. Previous work has computed overlap effects for double splitting g → gg → ggg. To make use of those results, one also needs calculations of related virtual loop corrections to single splitting g → gg in order to cancel severe (power-law) infrared (IR) divergences. This paper provides calculations of nearly all such processes involving gluons and discusses how to organize the results to demonstrate the cancellation. In the soft emission limit, our results reproduce the known double-log behavior of earlier authors who worked in leading-log approximation. We also present a first (albeit numerical and not yet analytic) investigation of sub-leading, single IR logarithms. Ultraviolet divergences appearing in our calculations correctly renormalize the coupling αs in the usual LPM result for leading-order g → gg.


1964 ◽  
Vol 82 (1) ◽  
pp. 3-81 ◽  
Author(s):  
Evgenii L. Feinberg ◽  
Dmitrii S. Chernavskii

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
L. Whitmore ◽  
R. I. Mackay ◽  
M. van Herk ◽  
J. K. Jones ◽  
R. M. Jones

AbstractThis paper presents the first demonstration of deeply penetrating dose delivery using focused very high energy electron (VHEE) beams using quadrupole magnets in Monte Carlo simulations. We show that the focal point is readily modified by linearly changing the quadrupole magnet strength only. We also present a weighted sum of focused electron beams to form a spread-out electron peak (SOEP) over a target region. This has a significantly reduced entrance dose compared to a proton-based spread-out Bragg peak (SOBP). Very high energy electron (VHEE) beams are an exciting prospect in external beam radiotherapy. VHEEs are less sensitive to inhomogeneities than proton and photon beams, have a deep dose reach and could potentially be used to deliver FLASH radiotherapy. The dose distributions of unfocused VHEE produce high entrance and exit doses compared to other radiotherapy modalities unless focusing is employed, and in this case the entrance dose is considerably improved over existing radiations. We have investigated both symmetric and asymmetric focusing as well as focusing with a range of beam energies.


1981 ◽  
Vol 8 (3) ◽  
pp. 205-213 ◽  
Author(s):  
Kisei Kinoshita ◽  
Akira Minaka ◽  
Hiroyuki Sumiyoshi

Sign in / Sign up

Export Citation Format

Share Document