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Abstract We have surveyed 21 reconnection exhaust events observed by Magnetospheric MultiScale in the low-plasma-βand high-Alfvén-speed regime of the Earth’s magnetotail to investigate the scaling of electron bulk heating produced by reconnection. The ranges of inflow Alfvén speed and inflow electronβecovered by this study are 800–4000 km s−1and 0.001–0.1, respectively, and the observed heating ranges from a few hundred electronvolts to several kiloelectronvolts. We find that the temperature change in the reconnection exhaust relative to the inflow, ΔTe, is correlated with the inflow Alfvén speed,VAx,in, based on the reconnecting magnetic field and the inflow plasma density. Furthermore, ΔTeis linearly proportional to the inflowing magnetic energy per particle, , and the best fit to the data produces the empirical relation ΔTe= 0.020 , i.e., the electron temperature increase is on average ∼2% of the inflowing magnetic energy per particle. This magnetotail study extends a previous magnetopause reconnection study by two orders of magnitude in both magnetic energy and electronβ, to a regime that is comparable to the solar corona. The validity of the empirical relation over such a large combined magnetopause–magnetotail plasma parameter range ofVA∼ 10–4000 km s−1andβe∼ 0.001–10 suggests that one can predict the magnitude of the bulk electron heating by reconnection in a variety of contexts from the simple knowledge of a single parameter: the Alfvén speed of the ambient plasma.
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This content will become publicly available on January 1, 2026
Extracting the dependence of directed flow differences on conserved charges
Recently, seven produced hadron species have been used to construct multiple hadron sets with given differences in the net electric charge (∆q) and strangeness (∆S) between the two sides. A nonzero directed flow difference △v1has been proposed as a consequence of the electromagnetic field produced in relativistic heavy ion collisions. Previously, we have shown with quark coalescence that Av1 and the slope difference △v′1depend linearly on both △qand ∆Swith zero intercept. Here we emphasize that a two-dimensional function or fit is necessary for extracting the △q- and △S-dependences of △v1. On the other hand, a one-dimensional fit gives a different value for the slope parameter of the ∆q- or ∆S-dependence. Furthermore, a one-dimensional fit is incorrect because its slope parameter depends on the arbitrary scaling factor of a hadron set and is thus ill-defined. We use test data of △v1to explicitly demonstrate these points.
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- PAR ID:
- 10621196
- Editor(s):
- Cheshkov, C; Guernane, R; Maire, A
- Publisher / Repository:
- EDP Sciences
- Date Published:
- Journal Name:
- EPJ Web of Conferences
- Volume:
- 316
- ISSN:
- 2100-014X
- Page Range / eLocation ID:
- 06007
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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