The decay of the new isotope171Re

Irradiating LaF₃-targets with³⁶Ar, the decay of the new isotope¹⁷¹Re was observed for the first time and its half-life determined to be 15.2(4) s. Based on the measuredγ- and X-ray data, a decay scheme could be constructed.     

Alpha decay of the new isotope 174Hg

Neutron deficient mercury isotopes were produced in the reaction ³⁶Ar + ¹⁴⁴Sm using bombarding energies of 180–230 MeV. Fusion products were separated in-flight from the primary beam using a gas-filled recoil separator. An alpha line with the alpha particle energy and half-life of (7069±11) keV and (2.1 _?0.7 ^+1.8 ) ms, respectively, was assigned to the new mercury isotope ¹⁷⁴Hg.     

Alpha decay of the new isotope172Au

The first observation of the extremely neutrondeficient nucleus¹⁷²Au is reported, produced using the fusion evaporation reaction⁷⁰Ge+¹⁰⁶Cd→¹⁷⁶Hg^* (E_x?64 MeV). Mass separated evaporation residues were implanted into a double-sided silicon strip detector, and the energy and time of subsequent decay events were recorded. The alpha decay of¹⁷²Au was measured with an energy =6860±10 KeV, corresponding to =7020±10 Kev, and a half-life of 4±1 ms. No evidence was seen for a proton decay branch, implying a limit ofb _p ≤ 2 %.     

New isotope159Lu and decay of158Lu,159,158Yb isotopes

Lutetium and ytterbium isotopes with masses A=159,158 have been produced by proton induced spallation reaction, and investigated by on-line mass separation and subsequent decay spectroscopy. A new isotope¹⁵⁹Lu (T_1/2=12.3±1 s) has been identified, and newγ-ray data have been obtained for the decay of¹⁵⁸Lu and^{159, 158}Yb.     

The decay of the isotopes179Ir and180Ir

The probability for non-radiative (n.r.) excitations in muonic²⁰⁹Bi was determined from a ( ^–,)-measurement by comparing the intensities of muonic X-ray transitions in single and coincidence spectra. The values of P_n.r(3p1s)=(17.9±2.0)% and P_n.r.(3d1s)=(3.0±2.2)% were measured for the first time. The strength of the n.r. decay of the 2p-level was found to be (4.2±2.2)%. The n.r. transition probabilities of two subcomplexes of the (2p1s)-transition leading to different mean excitation energies are (3.2±1.8)% and (5.0±2.0)%, respectively.We are indebted to the following institutes or organizations for financial support: Bundesministerium ffir Forschung und Technologic der Bundesrepubfik Deutschland contract number 06 BN 271 (HP, PD, HH, FR, CR), Foundation for Fundamental Research on Matter (FOM) and the Netherlands Organization of the Advancement of Pure Research (NWO) (JK, CTAMdL, WL, AT) and the Schweizer Nationalfonds (LS).     

The new isotope 270110 and its decay products 266Hs and 262Sg

The even-even nucleus ²⁷⁰110 was synthesized using the reaction ⁶⁴Ni + ²⁰⁷Pb. A total of eight α-decay chains was measured during an irradiation time of seven days. Decay data were obtained for the ground-state and a high-spin K isomer. The new nuclei ²⁶⁶Hs and ²⁶²Sg were identified as daughter products after α-decay. Spontaneous fission of ²⁶²Sg terminates the decay chain. The measured data are in agreement with calculations using the macroscopic-microscopic model and with self-consistent HFB calculations with Skyrme-Sly4 interaction. Received: 27 November 2000 / Accepted: 16 January 2001     

Identification and decay of102In,new neutron deficient isotope close to100Sn

¹⁰²In, [T_1/2=(24±4)s], has been identified for the first time using an on-line mass isotopic separator operating on nuclear reactions induced by heavy ions. Gamma-rays observed both in¹⁰²In→¹⁰²Cd decay and in-beam measurements allow to build a partial level scheme for¹⁰²Cd. Systematics of the two first excited states of even cadmium isotopes shows the special behaviour of the lightest one.     

Theβ + decay of the new isotope86Mo and the first observation of86m Nb

Theβ ⁺ decay of⁸⁶Mo has been firstly investigated by means ofβγ spectroscopy. The⁸⁶Mo nuclei were produced by fusion-evaporation reactions of⁵⁴ Fe (³⁵Cl, 1 p2n) and⁵⁸Ni (³²S,2p 2n) at beam energies of 103 and 120 MeV, respectively. Threeγ rays of 47.3, 49.8 and 187.0 keV were unambiguously identified to follow theβ ⁺ decay of⁸⁶Mo by results ofXγ andβγ coincidence and cross-bombardment. A half life and a maximumβ ⁺-ray energy of⁸⁶Mo were determined to be 19.6±1.1 s and 3.9±0.4 MeV, respectively. A decay scheme of⁸⁶Mo is proposed in this article. Furthermore, a decay of⁸⁶Nb has been studied using the same combinations of projectiles and targets, and a newβ-decaying isomer^86m Nb was observed with a half life of 56.3±8.3 s.     

Neutral B-meson decay and the search for hybrid mesons

We discuss the possibility that the decay of the neutral B mesons via a non-spectator mechanism might have a significant branching fraction into $\text{(}\text{q}\text{q}\text{g}\text{)}$ states. The lightest such hybrid mesons would be recognizable as narroe state of mass 1.6 ± 0.4$\text{GeV}\text{c}{}^2$ decaying predominantly into hadrons containing strange quarks.     

Double-electron capture of Se and the search for neutrinoless decay

Experimental results on the measurement of the double-electron capture (εε) decay process of ⁷⁴Se are described. This decay is particularly interesting, because ⁷⁴Se is almost degenerate to the second excited state at 1204 keV in the daughter nucleus ⁷⁴Ge. Such a degeneracy favors a neutrinoless decay because of the large phase-space suppression for a decay with two neutrinos. Subsequent de-excitation would generate a 2γ-ray cascade of 608 and 596 keV, whose coincident detection provides a unique signature for this particular εε process. The 2γ-ray cascade has been searched for by a HPGe γ-ray detector in coincidence with a NaI detector using 3 kg of natural selenium.     

Role of decay in the search for double-charm baryons

Double-charm baryons,whose components are two heavy charm quarks and one light quark,are part of a large family of hadrons predicted by the quark model.Studies on them are helpful to understand the hadron structure and the nature of the strong interaction.After efforts expended over decades of searching,experimental measurements achieved a breakthrough with the first observation of the double-charm baryon of■^++cc(ccu)via■^++cc→Λ^+c K^-π^+π^+ by the LHCb collaboration in 2017[1].Since then,the LHCb collaboration has been leading the experimental studies for doubly charmed baryons[2-6]because they are produced in considerably large numbers in the Large Hadron Collider(LHC).     

Alpha-particle decay of 218Th,a new isotope

A new isotope, ₉₀²¹⁸Th₁₂₈, has been found to decay with E_α = 9.67 ± 0.02 MeV and $\text{t}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 96 ± 7}\text{ns}$. The reduced α-particle width of ²¹⁸Th is about 1.4 times the value expected from the general trend of the N = 128 isotones with Z = 84?89.     

A new search for the allowed decay π0→4γ

A new search with increased detection efficiency has been made for the decay of the neutral pion into four photons, an allowed decay which is expected to be rare. We have observed no events, placing an upper limit on the branching ratio of 4.4 × 10^?6 at 90% confidence level.     

The search for D 0 → μ+μ− decay

Studies of rare decays of charmed mesons are used to test the Standard Model and search for new physics. In the present paper we review the progress in the experimental methods of searching for the D ⁰→μ⁺μ^? rare decay in recent studies of proton-nuclear and hadron-hadron interactions.     

First observation of the beta decay of117Pd and the discovery of a new isotope119Pd

In this paper we wish to report the first direct observations of the beta decays of¹¹⁷Pd and of a new isotope¹¹⁹Pd. The measuredβ-half-life is 4.3±0.3 s for¹¹⁷Pd. For¹¹⁹Pd, the existence of two beta-decaying states with the same half-life but of opposite parity cannot be excluded. The measured half-life for¹¹⁹Pd is 0.92±0.13 s. The observed beta half-lifes are in good agreement with the QRPA predictions. The observed level structure of¹¹⁷Ag and¹¹⁹Ag are discussed in the frame of the level systematics of the known odd Ag isotopes closer to stability.