Hasil untuk "Nuclear and particle physics. Atomic energy. Radioactivity"

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S2 Open Access 2025
Bridging quantum computing and nuclear Structure: Atomic nuclei on a trapped-ion quantum computer

S. Yoshida, Takeshi Sato, Takumi Ogata et al.

We demonstrate quantum simulations of strongly correlated nuclear many-body systems on the RIKEN-Quantinuum Reimei trapped-ion quantum computer, targeting ground states of oxygen, calcium, and nickel isotopes. By combining a hard-core-boson representation of the nuclear shell model with a pair-unitary coupled-cluster doubles ansatz, we achieve sub-percent relative error in the ground-state energies compared to noise-free statevector simulations. Our approach leverages symmetry-aware state preparation and particle-number post-selection to efficiently capture pairing correlations characteristic of systems with same-species nucleons. These findings highlight the viability of high-fidelity trapped-ion platforms for nuclear physics applications and provide a foundation for scaling to more complex nuclear systems.

4 sitasi en Physics
DOAJ Open Access 2025
Polarized $$W^+W^-$$ W + W - pairs at the LHC: Effects from bottom-quark induced processes at NLO QCD + EW

Thi Nhung Dao, Duc Ninh Le

Abstract We investigate the effects of the bottom-quark induced processes on the doubly polarized cross sections of $$W^+W^-$$ W + W - pair production at the LHC. The method to extract the on-shell single-top contribution is provided. Results for phenomenological and experimental analyses are given at next-to-leading order (NLO) QCD + EW accuracy, with the leading contribution from the gluon–gluon and photon–photon fusion included. We found that the contribution of the bottom-quark induced processes, after the subtraction of the on-shell tW channel, is largest for the doubly longitudinal polarization. At the integrated cross section level, using a fiducial ATLAS cut with a jet veto, the effect is $$9\%$$ 9 % compared to the NLO value of the light-quark contribution. It increases to $$13\%$$ 13 % after removing the jet veto. A bound of the tW interference is calculated for various kinematic distributions, showing that this interference effect is, in general, smaller for the no jet veto case. Relevant scale uncertainties are calculated to help us decide on the importance of this interference.

Astrophysics, Nuclear and particle physics. Atomic energy. Radioactivity
DOAJ Open Access 2025
Investigating late-time cosmology using Finsler-Randers geometry and Barthel connection: Observational constraints and implications

J. Praveen, S.K. Narasimhamurthy

In this study we explore cosmological anisotropies and dark energy using Finsler-Randers geometry, an extension of Riemannian geometry that incorporates directional dependence in the spacetime structure. We investigate whether Finslerian modifications including anisotropic corrections can provide a unified theoretical framework to explain both the observed cosmic acceleration and the anisotropies detected in the Cosmic Microwave Background and large-scale structure surveys. By introducing an anisotropic parameter η(t) with its parametrization we study its impact on cosmological models and compare the results with observational data from Cosmic Chronometers (CC), Baryon Acoustic Oscillations (BAO), and the Pantheon+ Type Ia Supernovae sample. The constraints on key cosmological parameters including the Hubble constant H0, matter density parameter Ωm, and the anisotropic parameter n, are derived using a Markov Chain Monte Carlo (MCMC) method. Our findings suggest that Finsler-Randers geometry provides a viable alternative to the standard ΛCDM model offering new insights into the nature of DE and large-scale anisotropies. We also examine the consistency of the anisotropic term n across different datasets evaluating its implications for both the evolution of the universe and potential deviations from isotropy. The results highlight the relevance of Finslerian geometry in cosmology and its potential to resolve some of the longstanding puzzles in contemporary cosmology.

Nuclear and particle physics. Atomic energy. Radioactivity
DOAJ Open Access 2025
Aspects of non-minimally coupled curvature with power laws

Anamaria Hell, Dieter Lüst

Abstract We consider a class of theories containing power-law terms in both the Ricci scalar and a scalar field, including their non-minimal couplings. As a first step, we systematically classify all non-trivial cases with a propagating scalar field that arise from the simplest general power-law formulation, which contains the minimal number of terms. We then analyze each case in detail, focusing on the structure of the degrees of freedom, by both formulating the theories in the Einstein frames and focusing on the singular points in the Jordan frame. We demonstrate that such theories can give rise to different, and sometimes unexpected structure of the modes, that can change at the leading order depending on the background.

Nuclear and particle physics. Atomic energy. Radioactivity
DOAJ Open Access 2025
Bootstrapping line defects in AdS3/CFT2

Gabriel Bliard, Diego H. Correa, Martín Lagares et al.

Abstract We study correlators of insertions along 1/2 BPS line defects in the holographic dual to type IIB string theory in AdS 3 × S 3 × T 4 with mixed Ramond-Ramond and Neveu Schwarz-Neveu Schwarz three-form flux. These defects break the symmetries of the bulk CFT2 as PSU(1, 1|2)2 × SO(4) → PSU(1, 1|2) × SU(2), defining displacement and tilt supermultiplets. We focus on the two-, three- and four-point functions of these supermultiplets, which we compute using analytic conformal bootstrap up to next-to-leading order in their strong-coupling expansion. We obtain a bootstrap result that only depends on two OPE coefficients. We perform a Witten diagram check of the bootstrap result, obtaining an holographic interpretation of the two OPE coefficients that are not constrained by the bootstrap procedure.

Nuclear and particle physics. Atomic energy. Radioactivity
DOAJ Open Access 2025
D-brane and exponential potentials inspire warm inflation and swampland conjecture

Shama Sadiq, Nadeem Azhar, N. Myrzakulov et al.

This research explores the rapid expansion period of the early universe by applying the Chaplygin gas model, an alternative cosmological framework, to analyze the dynamics of inflationary processes. This study assesses the compatibility of three widely studied scalar field potentials with the latest observational constraints derived from the Planck datasets. Our analysis includes inflationary parameters such as slow-roll parameters, scalar power spectrum PR, scalar spectral index ns, dissipative ratio R, tensor-to-scalar ratio r and running of the scalar spectral index dnsdln⁡k, within the theoretical frameworks of canonical scalar field dynamics and the Chaplygin gas cosmological model. These parameters help to paint a comprehensive picture of the inflationary epoch and its impact on the observable Universe. We also address the generalized ratio of the swampland de-Sitter conjecture through the expression of T′VV′T for three different potentials. We analyze inflation driven by a scalar field ϕ with decay rate Γ(ϕ,T)=CϕTaϕa−1, where Cϕ is a dimensionless coupling and a controls dissipation strength. Working in the strong dissipative regime (R≫1), we systematically investigate the background evolution and perturbation spectrum, deriving inflationary observables.

Nuclear and particle physics. Atomic energy. Radioactivity
S2 Open Access 2025
A Comprehensive Study On - How Effective Are Cyclotrons in Producing Radioisotopes for Medical Imaging Compared to Linear Accelerators or Nuclear Reactors?

Adhyayan Agarwal

This research paper explores the foundational concepts of nuclear physics and radioactivity, examining the structure of atomic nuclei, the nature of nuclear forces, and the principles governing radioactive decay. The study covers alpha, beta, and gamma decay in detail, incorporating mathematical models to describe half-life and decay constants. A key highlight of this research is the hands-on experience gained at the Variable Energy Cyclotron Centre (VECC), where practical exposure to cyclotron operations provided unique insights into particle acceleration and isotope production. This experience enriched the theoretical understanding of high-energy nuclear reactions and their applications in medicine and industry. The paper also discusses the broader implications of nuclear science, including nuclear energy, radiation safety, and ethical concerns. By combining theoretical study with direct experimental engagement, this research offers a holistic perspective on the evolving landscape of nuclear physics and its role in shaping scientific progress.

S2 Open Access 2024
Quantum sensing using atomic clocks for nuclear and particle physics

Akio Kawasaki

Technologies for manipulating single atoms have advanced drastically in the past decades. Due to their excellent controllability of internal states, atoms serve as one of the ideal platforms for quantum systems. One major research direction in atomic systems is the precise determination of physical quantities using atoms, which is included in the field of precision measurements. One of such precisely measured physical quantities is the energy differences between two energy levels in atoms, which is symbolized by the remarkable fractional uncertainty of 10−18 or lower achieved in the state-of-the-art atomic clocks. Two-level systems in atoms are sensitive to various external fields and can, therefore, function as quantum sensors. The effect of these fields manifests as energy shifts in the two-level system. Traditionally, such shifts are induced by electric or magnetic fields, as recognized even before the advent of precision spectroscopy with lasers. With high-precision measurements, tiny energy shifts caused by hypothetical fields weakly coupled to ordinary matter or by small effects mediated by massive particles can be potentially detectable, which are conventionally dealt with in the field of nuclear and particle physics. In most cases, the atomic systems as quantum sensors have not been sensitive enough to detect such effects. Instead, experiments searching for these interactions have placed constraints on coupling constants, except in a few cases where the effects are predicted by the Standard Model of particle physics. Nonetheless, measurements and searches for these effects in atomic systems have led to the emergence of a new field of physics. In some cases, they open new parameter spaces to explore in conventionally investigated topics, e.g., dark matter, fifth force, and other physics beyond the Standard Model. In other cases, these measurements provide alternative experimental approaches to established topics, e.g., variations of fundamental constants searched for astronomically and nuclear structure studied in high-energy scattering experiments. The use of atomic clocks as quantum sensors for phenomena originating from nuclear and particle physics evolved significantly in the past decades. This paper highlights the recent developments in the field.

1 sitasi en Physics
DOAJ Open Access 2024
Gravitationally induced unified relation among duality, coherence, steering, and maximal average fidelity

Duo-Duo Chen, Dong-Dong Dong, Xue-Ke Song et al.

Abstract Recently, numerous measures have been proposed for quantifying the quantumness of a given system, and the existence of intrinsic connections among quantum resource measures has been proven. Here, we study the unified relationship between duality, first-order coherence, three-setting linear steering inequality, and maximum average fidelity between two masses due to gravity. Under gravitational inducement, an equivalent relationship was identified between the first-order coherence and duality. The coherence of a system can be controlled by adjusting arm lengths and the distance between the arms of an interferometer. In most cases, the first-order coherence of a system cannot be maximised. Furthermore, a trade-off relationship between gravitationally induced duality and steering violations was derived. We can adjust the arm length and distance between the arms of the interferometer such that the steering violation reaches its maximum at phase $$\pi $$ π . The results show that the value of the steering violation is always greater than 1; that is, the state of the system is steerable. In addition, we explored the intrinsic relationship between duality and the maximal average fidelity due to gravity. In most cases, the maximum average fidelity of the system is greater than 2/3, indicating that the state is useful for quantum teleportation. These results are important for investigating the intrinsic relationships among various quantum resources within the framework of gravity.

Astrophysics, Nuclear and particle physics. Atomic energy. Radioactivity
DOAJ Open Access 2024
Nonresonant renormalization scheme for twist-2 operators in SU(N) Yang–Mills theory

Francesco Scardino

Abstract Recently, the short-distance asymptotics of the generating functional of n-point correlators of twist-2 operators in SU(N) Yang–Mills (YM) theory has been worked out in Bochicchio et al. (Phys Rev D 108:054023, 2023). The above computation relies on a basis change of renormalized twist-2 operators, where $$-\gamma (g)/ \beta (g)$$ - γ ( g ) / β ( g ) reduces to $$\gamma _0/ (\beta _0\,g)$$ γ 0 / ( β 0 g ) to all orders of perturbation theory, with $$\gamma _0$$ γ 0 diagonal, $$\gamma (g) = \gamma _0 g^2+\cdots $$ γ ( g ) = γ 0 g 2 + ⋯ the anomalous-dimension matrix and $$\beta (g) = -\beta _0 g^3+\cdots $$ β ( g ) = - β 0 g 3 + ⋯ the beta function. The construction is based on a novel geometric interpretation of operator mixing (Bochicchio in Eur Phys J C 81:749, 2021), under the assumption that the eigenvalues of the matrix $$\gamma _0/ \beta _0$$ γ 0 / β 0 satisfy the nonresonant condition $$\lambda _i-\lambda _j\ne 2k$$ λ i - λ j ≠ 2 k , with $$\lambda _i$$ λ i in nonincreasing order and $$k\in {\mathbb {N}}^+$$ k ∈ N + . The nonresonant condition has been numerically verified up to $$i,j=10^4$$ i , j = 10 4 in Bochicchio et al. (Phys Rev D 108:054023, 2023). In the present paper we provide a number theoretic proof of the nonresonant condition for twist-2 operators essentially based on the classic result that Harmonic numbers are not integers. Our proof in YM theory can be extended with minor modifications to twist-2 operators in $$\mathcal {N}=1$$ N = 1 SUSY YM theory, large-N QCD with massless quarks and massless QCD-like theories.

Astrophysics, Nuclear and particle physics. Atomic energy. Radioactivity
DOAJ Open Access 2024
Superconformal indices of N $$ \mathcal{N} $$ = 4 Chern-Simons matter theories

Bohan Li, Dan Xie, Wenbin Yan

Abstract Gaiotto and Witten found that one can construct 3d N $$ \mathcal{N} $$ = 4 Chern-Simons matter theories by using N $$ \mathcal{N} $$ = 4 SCFT whose momentum map of global symmetries satisfy special condition. Usually, one uses free hypermultiplet and twisted hypermultiplet, and more recently it was found that strongly coupled theory such as 3d version of T N theory and Argyres-Douglas matter can also be used. In this paper, we compute the superconformal index of these N $$ \mathcal{N} $$ = 4 theories and derive the Coulomb/Higgs limit. Our results determine the moduli space of vacua, which is used to check various interesting mirror symmetry involving CSM theory and usual N $$ \mathcal{N} $$ = 4 gauge theory.

Nuclear and particle physics. Atomic energy. Radioactivity
DOAJ Open Access 2024
Effect of Temperature on Aluminium Powder Flowability and Spreadability

Mozhdeh Mehrabi, Fatemeh Ali Akbar Talebi, Nathan Berry et al.

In powder-based Additive Manufacturing (AM) the precise control of process parameters plays a significant role in the quality and efficiency of the printing process. Among these, the effect of temperature has received less attention in the literature, although it is a significant factor that influences the inter-particle forces and, consequently the powder flow and spreading behaviour of powders. In selective laser sintering (SLS) or selective laser melting (SLM), pre-heating the chamber and powder bed is a required step prior to sintering, hence, the temperature can significantly influence the layer adhesion and spread quality. In this context, the present study explores the effect of elevated temperature on the flow and spreading behaviours of AlSi10Mg powders. The flow properties of two different grades of aluminium alloy powders are characterised using the Carney and Hall flow tests, angle of repose and shear test techniques at different temperatures and correlated with the spreading behaviour at elevated temperatures, measured using the spreading rig with a heated bed developed at the University of Leeds. This study revealed that at elevated temperatures the spreadability of AlSi10Mg powders worsens because of changes in interparticle forces and particle surface interactions.

Technology (General), Nuclear and particle physics. Atomic energy. Radioactivity
S2 Open Access 2024
Fundamentals of Nuclear Physics and Technology I

A. Šagátová

This university textbook provides the first part of basic knowledge in nuclear physics and technology. It focuses on the correct understanding of the problematics of radioactivity of atomic nuclei. The textbook describes the structure and forces of atomic nuclei with background in standard model of elementary particles. It discusses the radioactive decay law as well as the activation of atomic nuclei. It offers the overview of stabilisation of radioactive nuclei via radioactive decay, gamma emission or spontaneous fission. At the end of individual chapters, students will find exercises for practicing their correct understanding of the discussed topics: the atomic nuclei, the radioactivity and the radioactive decays. All exercises are based on real examples with actual parameters of nuclei. The correct answers to problems can be found in the rear part of the textbook. The textbook also responds to the recent methods and knowledge in the field of nuclear physics and encourages the students to use the global databases involving latest results of world leading research centres in nuclear physics and technology. The textbook is primary dedicated to the students of nuclear power engineering and nuclear technology, but it can also enrich students of other study fields of natural science and technology, as well as the employees in the nuclear power engineering with a different background than nuclear.

S2 Open Access 2023
Detection and Calibration of Low-Energy Nuclear Recoils for Dark Matter and Neutrino Scattering Experiments

Jingke Xu, P. Barbeau, Ziqing Hong

Detection of low-energy nuclear recoil events plays a central role in searches for weakly interacting massive particle (WIMP) dark matter interactions with atomic matter and studies of coherent neutrino scatters. Precise nuclear recoil calibration data allow the responses of these dark matter and neutrino detectors to be characterized and enable in situ evaluation of an experiment's sensitivity to anticipated signals. This article reviews the common methods for detection of nuclear recoil events and the wide variety of techniques that have been developed to calibrate detector response to nuclear recoils. We summarize the main experimental factors that are critical for accurate nuclear recoil calibrations, investigate mitigation strategies for different backgrounds and biases, and discuss how the presentation of calibration results can facilitate comparison between experiments. Lastly, we discuss the challenges for future nuclear recoil calibration efforts and the physics opportunities they may enable. Expected final online publication date for the Annual Review of Nuclear and Particle Science, Volume 73 is September 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

4 sitasi en Physics

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