Zakopane 2026 Conference on Nuclear Physics

The rapid neutron-capture (r-) process produces heavy elements in the mass range $70\leq A\leq209$, including actinides such as uranium and thorium. A defining feature of this process is its characteristic abundance distribution. It possesses a small yet distinct enhancement around A$\approx$160, known as the rare-earth peak. The origin of this peak remains an open question and is thought to...

The study of projectile breakup in heavy-ion interactions has been a topic of interest in recent years. At energies slightly above the Coulomb barrier, reactions are typically characterized by complete fusion (CF) and incomplete fusion (ICF)/breakup fusion (BUF) processes, with their relative contributions varying based on the incident energy. Recent experiments have shown that the breakup...

Collective dynamics in atomic nuclei arise from correlated nucleonic motion and manifest across both small- and large-amplitude excitation regimes, which are traditionally treated using distinct theoretical frameworks. In this work, we develop a unified Bayesian inference approach that consistently constrains nuclear structure parameters from diverse experimental observables spanning these...

Nucleosynthesis of elements beyond iron is an interesting area of research as it describes the evolution of our universe. It is governed mainly by slow ($s$-process), rapid ($r$-process) neutron capture, and $p$-process. On the neutron-deficient side of the valley of stability, there is a small fraction of the heavy elements known as $p$-nuclei. 35 stable isotopes in the mass region $^{74}$Se...

Since the discovery of nuclear fission by Hahn and Strassmann in 1939, it has remained a subject of sustained research interest. Nuclear fission is a fascinating example of large-scale rearrangement of strongly interacting nucleons within a finite many-body system. Despite decades of extensive experimental and theoretical efforts, several aspects of the fission process are still not fully...

This poster presents the methodology and results of an experimental study on inelastic proton-induced excitations of a $^{64}$Ni target at beam energy E = 180 MeV. The measurements were conducted at the Cyclotron Centre Bronowice (CCB) of the Henryk Niewodniczański Institute of Nuclear Physics PAN in Krakow. The experiment utilized a proton beam to excite the target nuclei, followed by the...

The Total Absorption Spectrometers (TAS) are designed to determine a true $\beta$ decay pattern and energy of the decay of fission products like neutron-rich nuclei produced in this process. In certain nuclei many $\beta$ decays, associated with low probabilities, contribute to numerous final, high-energy states in the region of high density. De-exciting $\gamma$ rays from such a levels are...

The region of neutron-rich nuclei around the $N=40$ subshell closure and the $Z=28$ proton shell is of particular interest for studying the evolution of nuclear structure, including shape coexistence, collectivity, and decay mechanisms far from stability. While $^{68}$Ni was initially considered a doubly magic nucleus, experimental studies of neighboring isotopes have revealed pronounced...

The concept of nuclear pairing plays a central role in explaining a wide range of nuclear phenomena, including separation energies, the structure of low-lying spectra, and giant resonances. While most theoretical descriptions of pairing rely on phenomenological schematic models or energy density functional approaches, recent developments in chiral interactions open the path toward ab-initio...

This study details the experimental investigation of $^{208}$Pb nuclei excitation through the inelastic scattering of a 155 MeV proton beam. The measurements were carried out at the Cyclotron Centre Bronowice (CCB) IFJ PAN, utilizing a multi-detector setup designed to capture the complex decay patterns of the excited targets.

The experimental configuration comprised the KRATTA...

The SilCA (Silicon Coulex Array) scattering chamber, developed at the Heavy Ion Laboratory in Warsaw to accommodate various particle detectors, including a CD-like annular DSSD (Double-Sided Silicon Strip Detector) [1], was assembled at HIL Warsaw together with the EAGLE array [2] in late 2023. The setup was commissioned in-beam in November 2024 with the EAGLE spectrometer using the digital...

In this section we present the OM analysis and CC effects using the phenomenological Wood-Saxon potential (WSP) for the elastic scattering angular distribution of 9Be + 90Zr system. The detail of this potential can be found in several works. The projectile 9Be inelastic states were included in the coupling matrix and the same calculations were first repeated using WSP six parameters model...

In recent years, the study of heavy-ion fusion reactions at the sub-barrier energies has attracted considerable attention in both experimental and theoretical investigations. One of the interesting phenomena observed in this energy regime is the sub-barrier fusion enhancement. The enhancement observed in the sub-barrier fusion cross sections over the predictions of one-dimensional barrier...

Study of nuclei near proton shell closure $Z=82$ is important, as interplay between different shapes has been observed in this region. The proton Fermi level for Tl lies near the $3s_{1/2}$ orbital, but highly shape driving $h_{9/2}$ and $i_{13/2}$ Nilsson orbitals intrude in this region at moderate deformation, the neutron Fermi level also lies near $i_{13/2}$ orbital, above $N=100$. The...

The direct determination of nuclear reaction rates at thermal energies remains a central challenge in nuclear astrophysics and strongly coupled plasma physics, where fusion occuring far below the Coulomb barrier is strongly influenced by electron screening and many-body effects [1]. Deuteron–deuteron (d–d) reactions provide a sensitive probe of these conditions, with relevance for both...

Octupole correlations in barium isotopes have been experimentally reported up to $N$=90 [1,2], with more recent evidence suggesting that this behaviour may persist up to $N$=94 [3]. The same study, together with symmetry-conserving configuration mixing (SCCM) calculations, supports an evolution toward increasingly quadrupole-deformed shapes accompanied by sustained octupole correlations in...

The nuclei around the A ∼ 130 mass region belong to the category of transitional nuclei, where the axial symmetry is broken, and the non-axial degree of freedom plays an essential role in determining the properties of these nuclei. The Xe isotopes in the A∼ 130 region are of particular interest as recent investigations of the excited states of the 125,127Xe have indicated triaxial shapes using...

Different decay modes of complete / incomplete fusion and pre-equilibrium [1] have been investigated in $^{12}$C+$^{116}$Sn system. The channel-by-channel fusion cross-sections of $^{126, 124}$Ba ($x$n), $^{125,123}$Cs (p$x$n), $^{123,122,121,120}$Xe ($\alpha$$x$n), $^{123, 122, 121, 120}$I ($\alpha$p$x$n) and $^{117}$Te (2$\alpha$$3$n) residues have been measured at E$_{\textrm{lab}}$...

Thermal motion and thermodynamic properties of nuclei influence nucleosynthesis in stellar environments. In macroscopic conductors, pairing phase transitions show a sharp heat capacity discontinuity at the transition temperature [1]. However, in nuclei, the smaller radius compared to pair coherence length leads to fluctuations, suppressing the discontinuity and resulting in a shallow "kink"...

Neutron-induced fission reaction cross sections are crucial in various fields of nuclear science and technology. Experimental data from these reactions play a key role in understanding nuclear processes at high excitation energies, contributing to the development and refinement of models describing spallation, nuclear fragmentation, and binary fission. Moreover, accurate cross-section data are...

Recent decades have witnessed exponential growth in both the quality and volume of experimental nuclear data, driven by advancements in detector technologies and accelerator capabilities. Gamma-ray spectroscopy has particularly benefited from these improvements, with large-scale spectrometers such as GRIFFIN and TIGRESS at TRIUMF enabling collection of increasingly complex, high-dimensional...

Rare-earth nuclei are known to exhibit a pronounced shape transition from spherical to well-deformed configurations in the vicinity of the N = 104 mid-shell region. Within the ytterbium isotopic chain, the neutron-rich isotopes $^{176}$Yb (N = 106) and $^{178}$Yb (N = 108) lie firmly on the deformed side of this transition, as evidenced by their R$_{4/2}$ = E(4$_1^+$) / E(2$_1^+$) ratios...

Quantum computation has shown great potential for studying many-body systems, where computational challenges become substantial due to the exponential growth of Hilbert spaces with the number of particles. Such approaches have also been explored in nuclear physics. In these frameworks, wavefunctions obtained from quantum simulation methods can be used to compute expectation values of one- and...

One of the most interesting phenomena in the nuclear structure physics is the competing excitation modes of collective and single-particle motions. In recent decades, studies of rotational band structures in transitional nuclei with A$\sim$100 mass number have revealed numerous related phenomena, $e.g.$ signature inversion, band termination, appearance of chiral rotational structures and...

The nuclei in the south of 208Pb, which is so called “blank spot” in the nuclear chart, remain experimentally less explored than other neutron-rich regions because of the difficulty in producing and identifying these nuclei with sufficient yield. In particular, the Re isotopes with Z=75 provide a sensitive testing ground for studying the evolution of nuclear shape. With increasing neutron...

The study of nuclear structure under conditions of extreme excitation has emerged as one of the thrust areas of contemporary nuclear physics research, motivated by both experimental advances in accessing exotic nuclei near drip lines [1] and their relevance to astrophysical environments [2]. Structural transitions involving changes in deformation and shell effects provide critical insight into...

The observation of asymmetric fission in the pre-actinide nucleus $^{180}$Hg at low excitation energies has renewed considerable interest in the role of shell effects in the fission process. At the same time, understanding the competition between quasi-fission (QF) and fusion–fission (FF) remains crucial for elucidating the formation mechanism of super heavy elements (SHEs). Since the...

The evolution of nuclear shell structure in exotic nuclei provides key insights into the
fundamental nature of nuclear forces. In nuclei far from stability, conventional magic
numbers can disappear, while new ones may emerge, a phenomenon known as shell evolution [1].
A well-known example is the evolution of the N=28 shell gap from $^{40}$Ca to $^{48}$Ca,
which has been successfully...

Cluster structure of stable/unstable weakly bound nuclei have been a topic of immense research interest. A number of interesting observations and features related to breakup of projectile/ejectile in the vicinity of target nucleus have been revealed with stable 6,7Li, 9Be projectiles. However, there are only few exclusive charged particle coincidence studies performed for probing the cluster...

A comprehensive understanding of the heavy-ion (HI)–induced fusion–fission process is important for fundamental nuclear physics, superheavy element synthesis, astrophysical applications, and the production of medically relevant isotopes. Therefore, a systematic study of the fusion–fission mechanism is essential to understand the complex dynamical evolution of the composite system formed in...

Bound-state $\beta^-$-decay is a rare radioactive process where the created electron is trapped in an atomic orbital instead of being emitted. It can be observed in highly ionized atoms in particular when normal beta-decay is energetically forbidden, but bound-state decay is still possible. In this work, we present a systematic study on the bound-state $\beta^-$-decay of $^{202,204,205}$Tl...

The odd--odd iodine isotopes are known to exhibit a rich variety of nuclear structures, particularly high-$K$ isomeric states~\cite{ref1}. These isomers are generally associated with coupled configurations involving the proton intruder $g_{9/2}$ orbital and the neutron intruder $h_{11/2}$ orbital~\cite{ref2}. In particular, an isomeric state with spin--parity $I^{\pi} = 7^{-}$, originating...

Studies of exotic atomic nuclei have shown that the magic nucleon numbers observed near the valley of stability (2, 8, 20, 28, 50, 82, 126) can slightly vary. The vast majority of theoretical calculations consider the 100Sn nucleus, with 50 neutrons and protons, to be magic; however, we have not yet found clear experimental evidence for this. Beyond this fundamental question of nuclear...

Light charged particle energy spectra were measured in coincidence with fission fragments in the $^{11}\mathrm{B} + {}^{232}\mathrm{Th}$ reaction at $E_{\mathrm{lab}} = 64$~MeV. The pre-scission proton multiplicity ($\pi_{\mathrm{pre}}$) was determined using the Moving Source Disentangling Analysis (MSDA). A comparison of the obtained $\pi_{\mathrm{pre}}$ and previously reported value for the...

Evaporated light particles carry information of the temperature, angular momentum, deformation, and lifetime of the emitting source. Earlier studies have shown that neutron, proton, and α-particle spectra may carry signatures of dynamical deformation, particularly when the formation and decay time scales of the composite system are comparable. In particular, the slopes of the emitted particle...

The giant dipole resonance (GDR) serves as a primary probe for investigating collective excitations and structural evolution in nuclei. In the actinide region, particularly for Thorium and Neptunium isotopes, the resonance structure is significantly influenced by large quadrupole deformation combined with strong pairing correlations, leading to a complex broadening and splitting of the $E1$...

We present numerical simulations of the collision and subsequent evolution of two superfluid fermionic systems in one dimension. The study focuses on the dynamics of two initially separated superfluid systems that begin to interact following the removal or modification of a potential barrier. This interaction induces excitations manifested as particle flow and oscillations of both the density...

Chiral rotation has been found in many triaxial nuclei in the $A\sim$ 80, 100, 130, and 190 mass regions [1]. In the $A\sim$ 100 mass region rotational bands in the $^{104}$Rh nucleus have been studied, using the $^{96}$Zr($^{11}$B,3n) fusion-evaporation reaction at a beam energy of 40~MeV with the Gammasphere spectrometer.
Earlier two negative-parity chiral doublets [2,3] were identified...

The ultrarelativistic heavy ions collisions with fixed targets gives opportunity to verify the usability of nuclear models. The high energy particles produced in the participant zone in the Quark-Gluon plasma (QGP) are interacting electromagnetically with charged remnants- spectators and changes trajectories of the charged particles [1,2]. Studying de-excitation processes such as evaporation,...

Nuclear shape coexistence, defined as the presence of competing intrinsic configurations such as spherical, prolate and oblate shapes at comparable excitation energies within a single nucleus, is now established as a widespread phenomenon across the nuclear chart, arising from the interplay of shell effects, pairing correlations and collective deformation mechanisms [1, 2]. While its...

We construct an equation of state for isentropic dark-matter-admixed neutron stars (DMANS) with a hot core and relatively cold crust incorporating self-consistent temperature and DM density profiles
for GeV-scale fermionic DM. We show that the enhancement of central stellar density due to DM accumulation, previously reported for cold neutron stars, remains robust. Substantial observable...

Octupole correlations, resulting from the long-range, octupole-octupole interaction between nucleons occupying pairs of orbitals with Δj=Δl=3 have been proved to be one of the major cornerstone in nuclear structure physics. However, the evidence for static octupole deformation leading to a heart-shaped nucleus has been rare [1]. The band structure involving alternate parity states and...

Nuclear interactions constitute the fundamental basis for understanding the structure of nuclear matter. However, despite significant theoretical progress—particularly within the framework of chiral effective field theory (ChEFT)—noticeable discrepancies between experimental data and theoretical predictions persist, especially in few-nucleon systems. To expand the experimental database with...

The moment of inertia for pair rotation (P-MoI) characterizes the spectral properties of pair rotational collective mode associated with the spontaneous breaking of gauge symmetry in superfluid nuclei. As a collective excitation in the particle-number gauge space, the pair rotation restores the broken symmetry through the phase rotation of the order parameter along the bottom of the...

The GADAST detector array [1] is being developed within the EXPERT project [3] of the Super-FRS Experiment Collaboration at FAIR [2]. Its principal task is to tag γ-ray de-excitation of daughter nuclei produced in exotic radioactive decays, and to detect of protons and other light charged particles emitted with sufficiently large transverse momentum. Previous characterization of the GADAST...

It is well established fact that nearly $50\%$ of all heavy neutron-rich nuclei (viz. in the range Fe to U) are produced via the rapid neutron capture process or $r$-process. This process is proposed to occur in explosive astrophysical sites like Core-collapse Supernovae and Neutron Star Mergers (NSM) [1]. The latter is already established observationally, via multi-messenger astronomy [2]....

Giant resonances (GR) are fundamental collective modes of nuclear excitation, offering profound insights into the many-body dynamics of nucleons. While the Giant Dipole Resonance (GDR) is a well-established tool for probing nuclear shapes and properties [1], the Isoscalar Giant Quadrupole Resonance (ISGQR) remains a challenging frontier in nuclear structure physics. Although theoretical models...

Nuclear reaction cross-section data in the medium-mass region are important for applications in medical isotope production, accelerator technology, astrophysics, and reactor design. Proton-induced reactions on Rb–Br isotopes have been investigated using the activation technique. Thin RbBr targets were irradiated with 15 MeV protons at the BARC-TIFR Pelletron Facility, India. The irradiation...

Quantum algorithms based on the variational quantum eigensolver (VQE) and ADAPT-VQE are implemented for ab initio nuclear structure calculations within the no-core shell model and full configuration interaction shell model frameworks, enabling an efficient treatment of nuclear many-body systems in large configuration spaces. Building on this, the Generator Coordinate Method (GCM) is formulated...

Using a Multi Step Shell Model (MSM) approach we analyze the excitation spectra of the alpha like nuclei 104Te and 136Te, by coupling two particle states above the doubly magic nuclei 100Sn and 132Sn. We build two particle states (pp, nn and pn) with which we describe the structure of the isotopes of Te, Sn and Sb through a Tamm-Dankoff Approach (TDA) with multipole-multipole residual...

Nuclear deformation is a prominent feature of nuclei far from stability, where deviations from conventional shell closures often lead to the emergence of various shapes. Characterising these shapes remains a significant challenge for both theory and experiment. In this work, we demonstrate that one-nucleon knockout reactions and their associated spectroscopic factors serve as a sensitive probe...

Anaïs Lépine, LP2iB, on behalf of the WISArD collaboration

The Standard Model (SM) of particle physics has proven to be a successful
theory describing three of the four fundamental interactions. However, some
open questions remain and motivate precise measurements to search for evidence
of physics beyond the SM predictions. Nuclear β-decay provides a sensitive
probe of the weak...

Doubly odd Cs nuclei are of particular interest due to the bands built on low-$\Omega$ $h_{11/2}$proton and high-$\Omega$ $h_{11/2}$ neutron orbitals, which exhibit distinct shape-driving effects [1]. The nuclei $^{124,126,128,130,132}$Cs have been reported to display chiral symmetry in the positive parity band based on the $\pi h_{11/2} \otimes \nu h_{11/2}$ configuration [2,3]. In this...

Exploring the new elements toward the high end of the nuclear chart is one of the most interesting topics in nuclear physics. The key ingredient to stabilize nucleus in this region is a nuclear shell structure and Z=114, 120, N=184 [1-4] are predicted to be new magic numbers. However, the access to such nuclei and study of their shell structure is limited by the very low cross sections. To...

Odd-mass, neutron-deficient nuclei in the vicinity of the Z = 82 closed shell are currently the subject of extensive experimental investigation due to the frequent occurrence of shape coexistence and nuclear isomerism in this region. In 2022, a new isomeric state in ¹⁷⁹Au was identified at an excitation energy of 1743(17) keV, with spin and parity of 19/2⁺ and a half-life of 2.16(8) µs. Due to...

There is a growing interest in studying harmonic oscillator nuclear shell closures, particularly far from the valley of stability. This is where the concept of the island of inversion arises [1], i.e., a region of the chart of nuclides where strong quadrupole correlations overcome the spherical mean-field shell gaps, leading to the emergence of energetically favoured deformed intruder states....

A sudden ground-state shape transition is known to occur at $N=60$ for Sr and Zr isotopes, accompanied by dramatic changes in their energy spectra [1]. In contrast, in Mo isotopes with $A\approx100$ the ground-state shape evolution appears to be more gradual, in accordance with the moderate change in $E_x(2_1^+)$ and mean-squared charge radii across $N=60$ [1]. At the same time, the energy of...

We are developing an emulator for nuclear many-body calculations based on Eigenvector Continuation (EC), a reduced-basis method applicable to both ab initio Hamiltonians and Energy Density Functional (EDF) approaches.

The method exploits the observation that the parametric evolution of low-lying eigenvectors is confined to a low-dimensional manifold embedded within the full Hilbert space. A...

As per the Bohr’s independence hypothesis [1], the formation and decay of a compound nucleus (CN) are independent processes. As such, a nuclear reaction occurs in two steps: (i) the incident particle is absorbed by the target nucleus to form a quasi-stable CN with energy shared among all the nucleons, (ii) the equilibrated CN decays after a long time ($\approx 10^{-16}$ sec.). The CN theory...

Constructing a unified effective nuclear force for configuration-interaction calculations has long been a challenge in nuclear structure physics. In this talk, we propose a solution starting from a monopole-based universal interaction. By performing configuration-interaction shell-model calculations alongside component-by-component sensitivity analyses, we investigate the distinct roles of...

Lanthanum ($Z = 57$) and lutetium ($Z = 71$) serve as ideal candidates to study proton-emission effects, which can be used to test nuclear models in extreme conditions. Near the N=82 shell closure, the Lu proton-emitting isotopes display a minor oblate deformation. This is in contrast with the proton-emitting La isotope, which is far from any shell closures and shows a strong prolate...

We report on two recently patented approaches for the determination of hadron beam energy and energy spread. Experimental data used for validation were collected at the Bronowice Cyclotron Center (CCB) and at the AIC-144 cyclotron operated by the Institute of Nuclear Physics PAS in Kraków. The obtained results confirm the applicability of the proposed diagnostic methods for real-time...