Mass measurements: 2023Wa10 (M.E.=-46806 42), 2011Tu02 (M.E.=-46937 85)

2023Wa10: ⁶⁵As was produced in ⁹Be(⁷⁸Kr,X) with E=460 MeV/nucleon ⁷⁸Kr beam from the accelerator at the Heavy Ion Research Facility in Lanzhou (HIRFL). Fragments were separated by the RIBLL2 separator and injected into the experimental cooler storage ring (CSRe). Measured time-of-flight. Deduced mass excess.

2017GoZT (thesis; also 2020Gi02): ⁶⁵As was produced in the fragmentation of a 350 MeV/nucleon ⁷⁸Kr beam at RIKEN. Fragments were identified and selected by the BigRIPS and the ZDS separators, and implanted into the WAS3ABi device consisting of 3 DSSSDs, surrounded by the EURICA array of Ge detectors for γ-ray detection. Measured E(p), I(p), implant-decay time correlations, Eγ. Deduced T_1/2

2011Tu02 (also 2011ZhZV): ⁹Be(⁷⁸Kr,X) E=483.4 MeV/nucleon at HIRFL. Measured time-of-flight. Deduced mass excess.

2014Ro14: ⁶⁵As was produced in the fragmentation of 70 MeV/nucleon ⁷⁸Kr beam with Ni target at GANIL. Fragments were selected with the LISE3 separator and identified by time-of-flight and energy loss. Measured half-life of ⁶⁵As ground-state decay by (fragment)β, (fragment)γ correlations using set of four Si detectors (an energy loss ΔE detector, a degrade, DSSD and Si(Li)) for particles surrounded by four HPGe Clover detectors, three EXOGAM and one mini-clover Ge detector for γ rays.

2002Lo13,2002Bl17: ⁶⁵As was produced by fragmentation of 73 MeV/nucleon ⁷⁸Kr beam at GANIL. Measured implant-β(t). Deduced T_1/2

1993Wi03: ⁶⁵As was produced by fragmentation of 75 MeV/nucleon ⁷⁸Kr beam by an enriched ⁵⁸Ni target and mass separation at NSCL. Measured T_1/2.

1991Mo10: ⁶⁵As was produced by fragmentation of 65 MeV/nucleon ⁷⁸Kr beam on an enriched ⁵⁸Ni target at NSCL. First observation of ⁶⁵As as recognized in 2010Sh34 compilation of isotope discovery

1991XuZZ: ⁶⁵As was produced by fragmentation of 20 MeV/nucleon ⁶⁴Zn beam incident on a Be target and mass separation at RIKEN; claims to be first identification of ⁶⁵As; no other data.

1990Ro15: search for proton radioactivity of ⁶⁵As was made with ⁴⁰Ca(³²S,αp2n) at E(³²S)=200 MeV and ⁴⁰Ca(²⁸Si,p2n) at E(²⁸Si)=175 MeV and mass separation at LBNL. No such activity was observed in the proton energy range of 200-700 keV. Authors conclude that ⁶⁵As must decay mostly by positron emission or by proton emission with T_1/2 < 100 μs.

1989Ho19: search for proton radioactivity of ⁶⁵As was made with ⁴⁰Ca(²⁸Si,p2n) at E(²⁸Si)=87 MeV and mass separation at Orsay. They looked for proton radioactivity in the energy range 250-600 keV and half-life of 10 μs to 100 ms. No such activity was observed and the authors established a lower production cross section limit of 1×10^-6 barn.

1988HoZL, 1989HoZQ: search for proton radioactivity of ⁶⁵As was made with ⁴⁰Ca(²⁸Si,p2n) at E(²⁸Si)=140 MeV and separation of reaction products with a mass analyzer at Daresbury. No evidence was found for proton decay of ⁶⁵As; the authors conclude that ⁶⁵As decays predominantly by positron emission with a weak proton decay branch or its half-life is less than 5 μs which is below the detection capability of their equipment.

Theoretical calculations:

2022Zo01,2021Ma33,2021Kl02,2019Zo02: calculated S(p), S(2p), mass excess

2021Qu01: calculated resonant states of ⁶⁴Ge(p,γ)

2017Ni16: calculated nuclear radius, single-particle energies

2014Bh16,2012Bh10: calculated binding energy, mass, S(p)

2013Co23: calculated levels, J, π, spectroscopic quadrupole moments

2003Mi23: calculated binding energy, quadrupole deformation

2001Pa02: calculated ground-state J, π, binding energy, deformation parameter, radius, S(p)

Q-value: ΔQ(β^-)=310 (syst,2021Wa16)

Q-value: S(2p)=4837 42, Q(ε)=9672 42, Q(εp)=4738 42, from mass excesses of ⁶⁵As measured by 2022Si20, and -56547.1 13 for ⁶³Ga, -56478.2 22 for ⁶⁵Ge, and -58832.8 14 for ⁶⁴Ge from 2021Wa16. Values from 2021Wa16: S(2p)=4970 80, Q(ε)=9540 80, Q(εp)=4610 80

Q-value: S(2n)=29580 220 (syst)