# Reanalyze the pulsar scenario to explain the cosmic positron excess considering the recent developments

## TL;DR

This paper reexamines pulsar contributions to the cosmic positron excess considering recent observations, proposing PSR B1055-52 as a promising source that aligns with AMS-02 and H.E.S.S. data, challenging previous candidates like Geminga.

## Contribution

It introduces a new analysis under the two-zone diffusion model, identifying PSR B1055-52 as a viable source of the positron excess based on recent observational constraints.

## Key findings

- PSR B1055-52 can reproduce AMS-02 positron spectrum features.
- The slow diffusion scenario favors B1055-52 as the primary source.
- Geminga is no longer a viable candidate under new constraints.

## Abstract

As the TeV halos around Geminga and PSR B0656+14 have been confirmed by HAWC, slow diffusion of cosmic rays could be general around pulsars, and the cosmic positron spectrum from pulsars could be significantly changed. As a consequence, the most likely pulsar source of the positron excess, Geminga, is no more a viable candidate under the additional constraint from Fermi-LAT. Moreover, the latest measurement by AMS-02 shows a clear cutoff in the positron spectrum, which sets a strict constraint on the age of the pulsar source. Considering these new developments we reanalyze the scenario in this work. By checking all the observed pulsars under the two-zone diffusion scenario, we propose for the first time that PSR B1055-52 is a very promising source of the positron excess. B1055-52 can well reproduce both the intensity and the high-energy cut of the AMS-02 positron spectrum, and may also explain the H.E.S.S $e^-+e^+$ spectrum around 10 TeV. Moreover, if the slow diffusion is universal in the local interstellar medium, B1055-52 will be the unique reasonable source of the AMS-02 positron spectrum among the observed pulsars.