scholarly journals Study of Λ-Hypernuclei with Stopped K− Reaction

1994 ◽  
Vol 117 ◽  
pp. 1-15
Author(s):  
Hirokazu Tamura ◽  
Ryugo S. Hayano ◽  
Haruhiko Outa ◽  
Toshimitsu Yamazaki
Keyword(s):  
Excited States ◽  
Branching Ratios ◽  
Future Prospects ◽  
Mesonic Decay ◽  
Peak Intensity ◽  
Momentum Spectra ◽  
Γ Ray ◽  
Improved Accuracy ◽  
First Time ◽  
Nuclear Targets

We summarize studies of Λ hypernuclei with stopped K− reaction carried out at KEK. The π− momentum spectra in the (stopped K−, π−) reaction were measured with light nuclear targets (4He, 7Li, 9Be, 12C and 16O). The ground and excited states of Λ4He, Λ12C and Λ16O were identified and their formation probabilities were measured. The branching ratios of π0-mesonic decay of Λ4He, Λ11B and Λ12C were measured for the first time with π0 coincidence. The lifetime of Λ4H was also determined with an improved accuracy. The π− peak intensity from Λ4H→4He+π− decay gave the Λ4H formation probabilities on these targets, where Λ4H is produced as hyperfragment except for the case of the 4He target. Concerning the formation mechanism of hyperfragments and their application to hypernuclear γ-ray spectroscopy, the running experiments and future prospects are also described.

FIRST γ-RAY SPECTROSCOPY AND ISOSPIN SYMMETRY STUDY OF THE N = Z - 2 NUCLEUS 44V

2010 ◽  
Vol 25 (21n23) ◽  
pp. 2028-2029 ◽  
Author(s):  
M. J. TAYLOR ◽  
M. A. BENTLEY ◽  
J. BROWN ◽  
R. WADSWORTH ◽  
P.E. KENT ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Shell Model ◽  
Excited States ◽  
State Of The Art ◽  
Isospin Symmetry ◽  
Charge Symmetry Breaking ◽  
Charge Symmetry ◽  
Model Calculations ◽  
Γ Ray ◽  
First Time

Excited states in the Tz = -1 nucleus 44 V have been observed for the first time. The states have been identified through recoil-γ-γ coincidences and comparison with analogue states in the mirror nucleus 44 Sc . Mirror energy differences have been extracted and compared to state-of-the-art fp shell-model calculations which include charge symmetry breaking forces.

NEW LEVELS AND TRANSITIONS IN 72Ge OBSERVED IN THE 72As(β++EC)72Ge DECAY

2008 ◽  
Vol 17 (06) ◽  
pp. 1061-1074
Author(s):  
SHUIFA SHEN ◽  
YAN LI ◽  
JIAHUI GU ◽  
FURONG XU ◽  
TINGDUN WEN ◽  
...  
Keyword(s):  
High Purity ◽  
Decay Scheme ◽  
Branching Ratios ◽  
Γ Rays ◽  
Γ Ray ◽  
First Time

The decay of 72 As has been investigated by means of γ-ray spectroscopy. The 72 As nuclei were produced through the 72 Ge (p, n)72 As reaction. The Compton-suppressed spectrometer and high-purity Ge detectors have been used in singles and in coincidence modes respectively to study γ-rays in the β++ EC decay of 72 As to 72 Ge . 79 γ-rays, among which 3 were observed for the first time, were reported. A decay scheme of 72 As including 1 new level is proposed that accommodates 77 of these transitions. Tentative spin and parity assignments are suggested for a number of levels according to the log ft values and γ-branching ratios.

scholarly journals Level Scheme of 102In first observed

2019 ◽  
Vol 3 ◽  
pp. 215
Author(s):  
E. Adamides ◽  
D. Seweryniak ◽  
B. Cederwal ◽  
J. Nyberg ◽  
C. Fahlander ◽  
...  
Keyword(s):  
Excited States ◽  
Level Scheme ◽  
Liquid Scintillator ◽  
Spectroscopic Methods ◽  
Nuclear Shell Model ◽  
Angular Correlations ◽  
Γ Ray ◽  
First Time ◽  
Nuclear Shell ◽  
Α Particles

Neutron deficient nuclei close to 100Sn have been investigated in-beam by particle and γ-ray spectroscopic methods using the NORDBALL detector array following the bombartment of a 54Fe target with a beam of 270 MeV 58Ni. Protons and α particles were identified with a 4π ΔΕ-type Si-multidetector and neutrons with a 1π liquid-scintillator-detectorassembly placed in the forward derection. Excited states of 102In were identified for the first time. The level scheme constructed from γ-γ-particle-coincidence and γ angular correlations is discussed and compared to the structure of neighboring nuclei in the framework of the nuclear shell model.

LOW-SPIN STATES OF 83Rb EXCITED IN THE 83Sr(β++EC)83Rb DECAY

2000 ◽  
Vol 09 (06) ◽  
pp. 471-485 ◽  
Author(s):  
XIAOHAN YU ◽  
SHUANGHUI SHI ◽  
JIAHUI GU ◽  
JINGYI LIU ◽  
WENXIN LI ◽  
...  
Keyword(s):  
Excited States ◽  
Gamma Rays ◽  
Half Life ◽  
Beam Energy ◽  
Decay Scheme ◽  
Branching Ratios ◽  
Spin States ◽  
New Information ◽  
Hpge Detectors ◽  
Γ Ray

Gamma-rays from the 83 Sr (β++ EC )83 Rb decay have been investigated with Compton suppressed HpGe detectors. The activity was produced via the 85 Rb (p,3n) reaction at 27.1 MeV beam energy. Singles in multispectra mode and γ–γ coincidence experiments were performed. Approximately 190 transitions including 94 new transitions and 19 new levels were assigned to 83 Rb , based on their measured half-life and/or observation in coincidence with well-known lines. A decay scheme has been constructed consisting of 41 excited states and 180 transitions in 83 Rb . Additional new information has been obtained on γ-ray branching ratios, log ft values, spins and parities.

The 23Na(α,γ)27Al reaction. A survey of the reaction and some properties of the 27Al nucleus

1969 ◽  
Vol 47 (15) ◽  
pp. 1545-1555 ◽  
Author(s):  
H. Röpke ◽  
N. Anyas-Weiss
Keyword(s):  
Excitation Energy ◽  
Excited States ◽  
Bound States ◽  
Branching Ratios ◽  
Angular Distributions ◽  
Particle Capture ◽  
Excitation Energies ◽  
Decay Modes ◽  
Γ Ray ◽  
27Al Reaction

The 23Na(α,γ) reaction has been studied in the region Eα = 2–3 MeV. The γ-ray spectra from a total of 16 resonances have been surveyed using a 40 cm3 Ge(Li) detector. Excitation energies, γ-ray decay modes, branching ratios, and γ-ray yields of these resonances are given. Below Eα = 2.7 MeV, all resonances have [Formula: see text] and the α-particle capture proceeds with [Formula: see text]. The resonances at Eα = 2.696 and 2.797 MeV have strong branches to the Jπ = 11/2+ state in 27Al at 4.509 MeV excitation energy. A measurement of γ-ray angular distributions at these resonances yields Jπ(2.969 res.) = 9/2+, 11/2 and Jπ(2.797 res.) = 9/2+ for the resonances, and Jπ(5.671) = 9/2+, 7/2 and Jπ(4.580) = 9/2+, 7/2 for bound states in 27Al. Investigation of this latter level at the Ep = 2.114 MeV resonance in the 26Mg(p,γ)27Al reaction restricts the spin to 7/2. New excited states in 27Al were found at Ex = 5.504, 5.671, and 7.815 MeV. A state at Ex = 5.499 MeV was confirmed.

Excited States in 53Mn by the 53Cr(p,nγ)53Mn Reaction

1973 ◽  
Vol 51 (17) ◽  
pp. 1840-1849 ◽  
Author(s):  
Woon-Hyuk Chung ◽  
D. M. Sheppard ◽  
W. C. Olsen ◽  
B. C. Robertson
Keyword(s):  
Statistical Model ◽  
Excited States ◽  
Energy Levels ◽  
Branching Ratios ◽  
Angular Distributions ◽  
Reaction Energy ◽  
Yield Curves ◽  
Mixing Ratios ◽  
Doppler Shift Attenuation ◽  
Γ Ray

The properties of the low-lying excited states in 53Mn were studied by measuring γ-ray angular distributions and lifetimes using the 53Cr(p,nγ)53Mn reaction. Energy levels of 53Mn have been found at 0.378, 1.288, 1.440, 1.619, 2.272, 2.405, 2.572, 2.670, 2.687, 2.705, 2.872, 2.876, 2.914, 2.947, 3.005, 3.095, 3.125, 3.183, 3.193, and 3.250 MeV. The measurement of γ-ray angular distributions and yield curves together with predictions based on the compound nuclear statistical model have enabled spin assignments to be made to the following excited states in 53Mn: 1.440 MeV (11/2), 1.619 MeV (9/2), 2.572 MeV (7/2), 2.687 MeV (7/2), 2.947 MeV (9/2), 3.005 MeV (5/2). Multipole mixing ratios and branching ratios were determined for some of the observed transitions. Lifetimes of nine excited states in 53Mn have been measured using the Doppler-shift attenuation method.

scholarly journals Low Energy Antikaon-nucleon/nuclei interaction studies by AMADEUS

2019 ◽  
Vol 199 ◽  
pp. 01014
Author(s):  
K. Piscicchia ◽  
M. Bazzi ◽  
G. Belloti ◽  
A. M. Bragadireanu ◽  
D. Bosnar ◽  
...  
Keyword(s):  
Cross Sections ◽  
Transition Amplitude ◽  
Nuclear Interaction ◽  
Branching Ratios ◽  
Analysis Procedure ◽  
Low Energy ◽  
Carbon Target ◽  
Pure Carbon ◽  
Nuclear Targets ◽  
Mass Spectroscopic Study

The AMADEUS experiment at the DAΦNE collider of LNF-INFN deals with the investigation of the at-rest, or low-momentum, K− interactions in light nuclear targets, with the aim to constrain the low energy QCD models in the strangeness sector. The 0 step of the experiment consisted in the reanalysis of the 2004/2005 KLOE data, exploiting K− absorptions in H, 4He, 9Be and 12C, leading to the first invariant mass spectroscopic study with very low momentum (about 100 MeV) in-flight K− captures. With AMADEUS step 1 a dedicated pure Carbon target was implemented in the central region of the KLOE detector, providing a high statistic sample of pure at-rest K− nuclear interaction. The first measurement of the non-resonant transition amplitude $\left| {{A_{{K^ - }n \to \Lambda {\pi ^ - }}}} \right|$ at $\sqrt s = 33\,MeV$ below the K̄N threshold is presented, in relation with the Λ(1405) properties studies. The analysis procedure adopted in the serarch for K− multi-nucleon absorption cross sections and Branching Ratios will be also described.

Study of the 1459-keV level in 19F by the 19F(p,p′γ)19F reaction

1970 ◽  
Vol 48 (7) ◽  
pp. 827-833 ◽  
Author(s):  
S. T. Lam ◽  
A. E. Litherland ◽  
J. J. Simpson
Keyword(s):  
Angular Distribution ◽  
Single Crystal ◽  
Linear Polarization ◽  
Proton Energy ◽  
Branching Ratios ◽  
Mixing Ratio ◽  
Γ Ray ◽  
Good Agreement

The 1459-keV level of 19F was populated by the 19F(p,p′γ)19F reaction at a proton energy of 2.78 MeV. The E2/M1 mixing ratio for the 1459 → 110 keV transition was determined to be [Formula: see text] from a combination of the γ-ray angular distribution and linear polarization and the nuclear lifetime. The γ-ray angular distribution was measured with a coaxial Ge(Li) detector and the γ-ray linear polarization with a planar Ge(Li) detector. The corresponding E2 and M1 transition strengths for a lifetime of 0.084 ± 0.020 ps are found to be [Formula: see text] and 0.10 ± 0.03 W.u. respectively. They are in good agreement with the particle–hole calculations of Benson and Flowers. The branching ratios of the 1459-keV level agree well with those of Poletti et al. The γ-ray transitions from the 1459-keV level provide a good example for demonstrating the usefulness of a single crystal Ge(Li) polarimeter.

scholarly journals Another SMEFT story: Z′ facing new results on ε′/ε, ∆MK and K → $$ \pi \nu \overline{\nu} $$

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Jason Aebischer ◽  
Andrzej J. Buras ◽  
Jacky Kumar
Keyword(s):  
Renormalization Group ◽  
Mass Difference ◽  
Branching Ratios ◽  
New Physics ◽  
Matrix Elements ◽  
Isospin Breaking ◽  
Left Handed ◽  
The Standard Model ◽  
First Time ◽  
Group Effects

Abstract Recently the RBC-UKQCD lattice QCD collaboration presented new results for the hadronic matrix elements relevant for the ratio ε′/ε in the Standard Model (SM) albeit with significant uncertainties. With the present knowledge of the Wilson coefficients and isospin breaking effects there is still a sizable room left for new physics (NP) contributions to ε′/ε which could both enhance or suppress this ratio to agree with the data. The new SM value for the K0 − $$ {\overline{K}}^0 $$ K ¯ 0 mass difference ∆MK from RBC-UKQCD is on the other hand by 2σ above the data hinting for NP required to suppress ∆MK. Simultaneously the most recent results for K+ → $$ {\pi}^{+}\nu \overline{\nu} $$ π + ν ν ¯ from NA62 and for KL → $$ {\pi}^0\nu \overline{\nu} $$ π 0 ν ν ¯ from KOTO still allow for significant NP contributions. We point out that the suppression of ∆MK by NP requires the presence of new CP-violating phases with interesting implications for K → $$ \pi \nu \overline{\nu} $$ πν ν ¯ , KS → μ+μ− and KL → π0ℓ+ℓ− decays. Considering a Z′-scenario within the SMEFT we analyze the dependence of all these observables on the size of NP still allowed by the data on ε′/ε. The hinted ∆MK anomaly together with the εK constraint implies in the presence of only left-handed (LH) or right-handed (RH) flavour-violating Z′ couplings strict correlation between K+ → $$ {\pi}^{+}\nu \overline{\nu} $$ π + ν ν ¯ and KL → $$ {\pi}^0\nu \overline{\nu} $$ π 0 ν ν ¯ branching ratios so that they are either simultaneously enhanced or suppressed relative to SM predictions. An anticorrelation can only be obtained in the presence of both LH and RH couplings. Interestingly, the NP QCD penguin scenario for ε′/ε is excluded by SMEFT renormalization group effects in εK so that NP effects in ε′/ε are governed by electroweak penguins. We also investigate for the first time whether the presence of a heavy Z′ with flavour violating couplings could generate through top Yukawa renormalization group effects FCNCs mediated by the SM Z-boson. The outcome turns out to be very interesting.

Status and Future Prospects for γ -ray Polarimetry

2006 ◽  
Vol 6 (S1) ◽  
pp. 237-246 ◽  
Author(s):  
M. L McConnell ◽  
P. F Bloser
Keyword(s):  
Future Prospects ◽  
Γ Ray
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