A new species of Dysdera Latreille, 1804 (Aranei: Dysderidae) from South Ossetia, the Greater Caucasus

A new species, Dysdera bakhanovi sp. n., is described from South Ossetia based on a male specimen. The new species is closely related to the Pontic-Caspian D. dunini Deeleman-Reinhold, 1988, the Anatolian D. anatoliae DeelemanReinhold, 1988 and D. krisis Komnenov et Chatzaki, 2016, and can be grouped within the anatoliae species-group. Males from the anatoliae species-group can be defined by the following characters: numerous small pits on carapace, non-sclerotized posterior apophysis, shortened psembolus bent anteriorly relative to the longitudinal axis of the bulb, and distal part of the psembolus bent at an angle of 90° from the posterior apophysis. Illustrations of the new species are provided. Distributional records of all species from the anatoliae species-group are mappe

The 6^{6}H states studied in the d(8He,α)d(^8\text{He},\alpha) reaction and evidence of extremely correlated character of the 5^{5}H ground state

The extremely neutron-rich system $^{6}$H was studied in the direct $^2\text{H}(^8\text{He},{^4\text{He}})^{6}$H transfer reaction with a 26 $A$ MeV secondary $^{8}$He beam. The measured missing mass spectrum shows a resonant state in $^{6}$H at $6.8(3)$ MeV relative to the $^3$H+$3n$ threshold. The population cross section of the presumably $p$-wave states in the energy range from 4 to 8 MeV is $d\sigma/d\Omega_{\text{c.m.}} \simeq 190(40)$ $\mu$b/sr in the angular range $5^{\circ}<\theta_{\text{c.m.}}<16^{\circ}$. The obtained missing mass spectrum is free of the $^{6}$H events below 3.5 MeV ($d\sigma/d\Omega_{\text{c.m.}} \lesssim 3$ $\mu$b/sr in the same angular range). The steep rise of the $^{6}$H missing mass spectrum at 3 MeV allows to show that $4.5(3)$ MeV is the lower limit for the possible resonant state energy in $^{6}$H tolerated by our data. According to paring energy estimates, such a $4.5(3)$ MeV resonance is a realistic candidate for the $^{6}$H ground state (g.s.). The obtained results confirm that the decay mechanism of the $^{7}$H g.s.\ (located at 2.2 MeV above the $^{3}$H+$4n$ threshold) is the ``true'' (or simultaneous) $4n$ emission. The resonance energy profiles and the momentum distributions of the sequential $^{6}$H \,\rightarrow \, ^5H(g.s.)+n\, \rightarrow \, ^3H+$3n$ decay fragments were analyzed by the theoretically-updated direct four-body-decay and sequential-emission mechanisms. The measured momentum distributions of the $^{3}$H fragments in the $^{6}$H rest frame indicate very strong ``dineutron-type'' correlations in the $^{5}$H ground state decay.Comment: 9 pages, 11 figure

Figs 1–3 in A new species of the genus Bifurcia (Aranei: Linyphiidae) from Primorsky krai, Russa

Figs 1–3. Habitus of Bifurcia dersuuzalai sp. n., male (1, 3) and female (2). 1–2 – lateralPublished as part of Fomichev, A.A. & Omelko, M.M., 2021, A new species of the genus Bifurcia (Aranei: Linyphiidae) from Primorsky krai, Russa, pp. 20-24 in Far Eastern Entomologist 435 on page 21, DOI: 10.25221/fee.435.3, http://zenodo.org/record/716615

Figs 1–4 in A NEW SPECIES OF THE GENUS BERLANDINA (ARANEI: GNAPHOSIDAE) FROM KAZAKHSTAN

Figs 1–4. Berlandina ilika sp. n., male palp. 1 – ventral view; 2 – prolateral view; 3 –Published as part of Fomichev, A.A. & Marusik, Yu.M., 2019, A NEW SPECIES OF THE GENUS BERLANDINA (ARANEI: GNAPHOSIDAE) FROM KAZAKHSTAN, pp. 13-18 in Far Eastern Entomologist 390 on page 15, DOI: 10.25221/fee.390.2, http://zenodo.org/record/716477

Figs 4–6 in A new species of the genus Bifurcia (Aranei: Linyphiidae) from Primorsky krai, Russa

Figs 4–6. Cephalic part of Bifurcia dersuuzalai sp. n., male (5–6) and female (4). 4–5 –Published as part of Fomichev, A.A. & Omelko, M.M., 2021, A new species of the genus Bifurcia (Aranei: Linyphiidae) from Primorsky krai, Russa, pp. 20-24 in Far Eastern Entomologist 435 on page 22, DOI: 10.25221/fee.435.3, http://zenodo.org/record/716615