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1. Electron capture in stars

   https://doi.org/10.1088/1361-6633/abf207  

   Langanke, K; Martínez-Pinedo, G; Zegers, R G (May 2021, Reports on Progress in Physics)

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2. Electron capture in stars

   Langanke, K.; Martínez-Pinedo, G.; Zegers, R. (September 2020, ArXivorg)

   Electron captures on nuclei play an essential role for the dynamics of several astrophysical objects. The capture rate can be derived in perturbation theory where allowed nuclear transitions (Gamow-Teller transitions) dominate, except at the higher temperatures achieved in core-collapse supernovae where also forbidden transitions contribute significantly to the rates. There has been decisive progress in recent years in measuring Gamow-Teller (GT) strength distributions using novel experimental techniques based on charge-exchange reactions. These measurements provide not only data for the GT distributions of ground states for many relevant nuclei, but also serve as valuable constraints for nuclear models which are needed to derive the capture rates for the many nuclei, for which no data exist yet. In particular models are needed to evaluate the stellar capture rates at finite temperatures, where the capture can also occur on excited nuclear states. There has also been significant progress in recent years in the modelling of stellar capture rates. This has been made possible by advances in nuclear many-body models as well as in computer soft- and hardware. Specifically to derive reliable capture rates for core-collapse supernovae a dedicated strategy has been developed based on a hierarchy of nuclear models specifically adapted to the abundant nuclei and astrophysically conditions present at the various collapse conditions. This manuscript reviews the experimental and theoretical progress achieved recently in deriving stellar electron capture rates. It also discusses the impact these improved rates have on the various astrophysical objects. (Abridged) 

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3. The electron-capture origin of supernova 2018zd

   https://doi.org/10.1038/s41550-021-01384-2  

   Hiramatsu, Daichi; Howell, D. Andrew; Van Dyk, Schuyler D.; Goldberg, Jared A.; Maeda, Keiichi; Moriya, Takashi J.; Tominaga, Nozomu; Nomoto, Ken’ichi; Hosseinzadeh, Griffin; Arcavi, Iair; et al (June 2021, Nature Astronomy)

   null (Ed.)
4. Observation of radiative double electron capture for

   https://doi.org/10.1002/xrs.3063  

   Kumara, Nuwan; La_Mantia, David_S; Buglione, Stephanie_L; McCoy, Craig_P; Taylor, Charles_J; White, Jacob_S; Kayani, Asghar; Tanis, John_A (June 2019, X-Ray Spectrometry)

   Radiative double electron capture (RDEC), occurring when two electrons are captured to a projectile ion with the simultaneous emission of a single photon, has been investigated. RDEC can be considered as the time inverse process of double photoionization. Strong evidence for RDEC is found in F⁹⁺+ N₂collisions and additionally for one‐electron F⁸⁺for which the probability for the process is expected to be considerably smaller. Preliminary values for the cross sections for RDEC have been determined. A significant advantage of the gas target is that multiple‐collision effects seen for a solid target are avoided due to the single‐collision conditions that prevail for gas targets. 

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5. Real-time capture of nuclear motions influencing photoinduced electron transfer

   https://doi.org/10.1039/d4sc01876a  

   Kim, Pyosang; Roy, Subhangi; Valentine, Andrew; Liu, Xiaolin; Kromer, Sarah; Kim, Tae Wu; Li, Xiaosong; Castellano, Felix N; Chen, Lin X (September 2024, Chemical Science)

   Although vibronic coupling phenomena have been recognized in the excited state dynamics of transition metal complexes, their impact on photoinduced electron transfer (PET) remains largely unexplored. This study investigates coherent wavepacket (CWP) dynamics during PET processes in a covalently linked electron donor–acceptor complex featuring a cyclometalated Pt(II) dimer as the donor and naphthalene diimide (NDI) as the acceptors. Upon photoexciting the Pt(II) dimer electron donor, ultrafast broadband transient absorption spectroscopy revealed direct modulation of NDI radical anion formation through certain CWP motions and correlated temporal evolutions of the amplitudes for these CWPs with the NDI radical anion formation. These results provide clear evidence that the CWP motions are the vibronic coherences coupled to the PET reaction coordinates. Normal mode analysis identified that the CWP motions originate from vibrational modes associated with the dihedral angles and bond lengths between the planes of the cyclometalating ligand and the NDI, the key modes altering their p-interaction, consequently influencing PET dynamics. The findings highlight the pivotal role of vibrations in shaping the favorable trajectories for the efficient PET processes. 

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