Light kaonic atoms spectroscopy provides a unique approach to study the low-energy strong interaction in the strangeness sector. Precise measurements of X-ray emission from light kaonic atoms provide ...valuable information on kaon-nucleus interaction at threshold without the need for extrapolation as required in scattering experiments. The SIDDHARTA-2 experiment at the DAΦNE collider of INFN-LNF is now poised to perform the challenging measurements of the K
−
- d 2p → 1s transition to extract the isospin-dependent antikaonnucleon scattering lengths. To achieve this goal, the background reduction is a crucial factor. This paper provides an overview of the SIDDHARTA-2 Veto-1 system, which uses scintillators outside the vacuum chamber to detect charged particles produced by K− absorption by the nucleus. The arrival time of these particles is correlated with the position where the kaonic atom has been created inside the setup, allowing for the rejection of kaons stopped outside the target cell, which is a critical component for reducing the background and improve the accuracy of the measurement.
The E2 nuclear resonance effect in kaonic atoms occurs when the energy of atomic de-excitation closely matches the energy of nuclear excitation, leading to the attenuation of some X-ray lines in the ...resonant isotope target. This phenomenon provides crucial information on the strong interaction between kaons and nuclei. The only nuclear E2 resonance effect observed so far was in the K
−
−
98
42
Mo isotope, measured by G. L. Goldfrey, G-K. Lum, and C. E. Wiegand at Lawrence Berkeley Laboratory in 1975. However, the 25 hours of data taking were not sufficient to yield conclusive results. In four kaonic Molybdenum isotopes (
94
42
Mo,
96
42
Mo,
98
42
and Mo, and
100
42
Mo), the nuclear E2 resonance effect is expected to occur at the same transition with similar energy values. To investigate this, the KAMEO (Kaonic Atoms Measuring Nuclear Resonance Effects Observables) experiment plans to conduct research on kaonic Molybdenum isotopes at the DAΦNE e
+
e
−
collider during the SIDDHARTA-2 experiment. The experimental strategy involves exposing four solid strip targets, each enriched with one Molybdenum isotope, to negatively charged kaons and using a germanium detector to measure X-ray transitions. In addition, a non-resonant
92
42
Mo isotope solid strip target will be used as a reference for standard non-resonant transitions.
A simple empirical relation is proposed to correlate the
K
-hindrance factor with the number of quasiparticles in the state configuration. The reduced hindrance
=
has been empirically modified such ...that
=
, instead of
=
, where
and
are the numbers of neutron and proton quasiparticles in the state configuration. In systematics, the modified hindrance factor can be used to uniquely determine the
K
-isomer state configuration.
Kaonic atoms measurements with SIDDHARTA-2 Sgaramella, F.; Bazzi, M.; Bosnar, D. ...
Journal of physics. Conference series,
02/2023, Letnik:
2446, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Abstract
The SIDDHARTA-2 collaboration is aiming to perform the challenging measurement of kaonic deuterium X-ray transitions to the ground state. This will allow to extract the isospin-dependent ...antikaon-nucleon scattering lengths, providing input to the theory of Quantum Chromodynamics (QCD) in the non-perturbative regime with strangeness. This work describes the SIDDHARTA-2 experimental apparatus and presents the results obtained during the commissioning phase realized with kaonic helium measurements. In particular, the first observation of the kaonic helium transitions to the 3s level (M-lines), reported in this work, represents a new source of information to study the kaonic helium cascade process and demonstrates the potential of the SIDDHARTA-2 apparatus, in the view of the ambitious kaonic deuterium measurement.
Abstract
The nuclear E2 resonance effect occurs when an atomic de-excitation energy is closely matched by a nuclear excitation energy. It produces an attenuation of some of the atomic X-ray lines in ...the resonant isotope target. Investigating the nuclear E2 resonance effect in kaonic atoms, important information about kaon-nucleus strong interaction can be provided. The only
K
−
−
42
98
Mo
nuclear resonance effect was measured by G. L. Goldfrey, G- K. Lum and C. E. Wiegand at Lawrence Berkeley Laboratory, in 1975. The nuclear E2 resonance effect was observed in 25 hours of data taking, not enough to provide a conclusive result. In four kaonic Molybdenum isotopes (
42
94
Mo
,
42
96
Mo
,
42
98
Mo
and
42
100
Mo
), the nuclear E2 resonance effect is expected at the same transition, with similar energy values. The KAMEO (Kaonic Atoms Measuring nuclear resonance Effects Observables) experiment plans to study the E2 nuclear resonance effect in kaonic Molybdenum isotopes at the DAΦNE e
+
e
−
collider, during the SIDDHARTA-2 experiment. The experimental strategy consists of exposing four solid strip targets, each enriched with one Molybdenum isotope, to negatively charged kaons, using a germanium detector for X-ray transition measurements. A further exposure of a non-resonant
42
92
Mo
isotope solid strip target will be used as reference for standard non-resonant transitions.
In the present work, Weisskopf hindrance factor
for electric and magnetic multipole transitions has been analyzed in the mass range
A
. An empirical correlation between the variation in
as a function ...of multipolarity has been determined. The pattern of
as a function of multipolarity and
as a function of the degree of
-forbiddenness are found indirectly similar to the pattern of the conversion coefficient with multipolarity. The odd-even nucleon staggering effect on
is discussed.
High precision light kaonic atoms X-ray spectroscopy is a unique tool for performing experiments equivalent to scattering at vanishing relative energies, to determine the antikaon–nucleus interaction ...at threshold without the need of extrapolation to zero energy. The SIDDHARTA-2 collaboration is going to perform the first measurement of kaonic deuterium transitions to the fundamental level, which is mandatory to extract the isospin dependent antikaon–nucleon scattering lengths. The SIDDHARTA-2 experiment is presently installed on the DA
Φ
NE collider of INFN-LNF. The preliminary results obtained during the machine commissioning phase in preparation for the kaonic deuterium data taking campaign, together with future perspectives for extreme precision kaonic atoms studies at DA
Φ
NE are presented.
The Jagiellonian Positron Emission Tomograph (J-PET) is the first PET device built from plastic scintillators. It is a multi-purpose detector designed for medical imaging and for studies of ...properties of positronium atoms in porous matter and in living organisms. In this article we report on the commissioning of the J-PET detector in view of studies of positronium decays. We present results of analysis of the positron lifetime measured in the porous polymer. The obtained results prove that J-PET is capable of performing simultaneous imaging of the density distribution of annihilation points as well as positron annihilation lifetime spectroscopy.
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