Journal of Physics G: Nuclear and Particle Physics - IOPscience

Journal of Physics G: Nuclear and Particle Physics - IOPscience
Journal of Physics G: Nuclear and Particle Physics
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Journal of Physics G: Nuclear and Particle Physics
publishes theoretical, experimental and computational research in nuclear and particle physics including all interface areas between these fields. The journal also publishes articles on nuclear and particle astrophysics.
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Impact factor
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Citescore
7.7
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The following article is
Open access
A next-generation liquid xenon observatory for dark matter and neutrino physics
J Aalbers
et al
2023
J. Phys. G: Nucl. Part. Phys.
50
013001
View article
, A next-generation liquid xenon observatory for dark matter and neutrino physics
PDF
, A next-generation liquid xenon observatory for dark matter and neutrino physics
The nature of dark matter and properties of neutrinos are among the most pressing issues in contemporary particle physics. The dual-phase xenon time-projection chamber is the leading technology to cover the available parameter space for weakly interacting massive particles, while featuring extensive sensitivity to many alternative dark matter candidates. These detectors can also study neutrinos through neutrinoless double-beta decay and through a variety of astrophysical sources. A next-generation xenon-based detector will therefore be a true multi-purpose observatory to significantly advance particle physics, nuclear physics, astrophysics, solar physics, and cosmology. This review article presents the science cases for such a detector.
The following article is
Open access
Motivations for early high-profile FRIB experiments
B Alex Brown
et al
2025
J. Phys. G: Nucl. Part. Phys.
52
050501
View article
, Motivations for early high-profile FRIB experiments
PDF
, Motivations for early high-profile FRIB experiments
This white paper is the result of a collaboration by many of those that attended a workshop at the facility for rare isotope beams (FRIB), organized by the FRIB Theory Alliance (FRIB-TA), on ‘Theoretical Justifications and Motivations for Early High-Profile FRIB Experiments’. It covers a wide range of topics related to the science that will be explored at FRIB. After a brief introduction, the sections address: section 2: Overview of theoretical methods, section 3: Experimental capabilities, section 4: Structure, section 5: Near-threshold Physics, section 6: Reaction mechanisms, section 7: Nuclear equations of state, section 8: Nuclear astrophysics, section 9: Fundamental symmetries, and section 10: Experimental design and uncertainty quantification.
The following article is
Open access
Searching for long-lived particles beyond the Standard Model at the Large Hadron Collider
Juliette Alimena
et al
2020
J. Phys. G: Nucl. Part. Phys.
47
090501
View article
, Searching for long-lived particles beyond the Standard Model at the Large Hadron Collider
PDF
, Searching for long-lived particles beyond the Standard Model at the Large Hadron Collider
Particles beyond the Standard Model (SM) can generically have lifetimes that are long compared to SM particles at the weak scale. When produced at experiments such as the Large Hadron Collider (LHC) at CERN, these long-lived particles (LLPs) can decay far from the interaction vertex of the primary proton–proton collision. Such LLP signatures are distinct from those of promptly decaying particles that are targeted by the majority of searches for new physics at the LHC, often requiring customized techniques to identify, for example, significantly displaced decay vertices, tracks with atypical properties, and short track segments. Given their non-standard nature, a comprehensive overview of LLP signatures at the LHC is beneficial to ensure that possible avenues of the discovery of new physics are not overlooked. Here we report on the joint work of a community of theorists and experimentalists with the ATLAS, CMS, and LHCb experiments—as well as those working on dedicated experiments such as MoEDAL, milliQan, MATHUSLA, CODEX-b, and FASER—to survey the current state of LLP searches at the LHC, and to chart a path for the development of LLP searches into the future, both in the upcoming Run 3 and at the high-luminosity LHC. The work is organized around the current and future potential capabilities of LHC experiments to generally discover new LLPs, and takes a signature-based approach to surveying classes of models that give rise to LLPs rather than emphasizing any particular theory motivation. We develop a set of simplified models; assess the coverage of current searches; document known, often unexpected backgrounds; explore the capabilities of proposed detector upgrades; provide recommendations for the presentation of search results; and look towards the newest frontiers, namely high-multiplicity ‘dark showers’, highlighting opportunities for expanding the LHC reach for these signals.
The following article is
Open access
Review of neutron yield from (
) reactions: data, methods, and prospects
D Cano-Ott
et al
2026
J. Phys. G: Nucl. Part. Phys.
53
023001
View article
, Review of neutron yield from (α, n) reactions: data, methods, and prospects
PDF
, Review of neutron yield from (α, n) reactions: data, methods, and prospects
Understanding the radiogenic neutron production rate from the (
) reaction is crucial in many areas of physics, including dark matter searches, neutrino studies, and nuclear astrophysics. In addition to its relevance for fundamental research, the (
) reaction also plays a significant role in nuclear energy technologies, for example by contributing to neutron production in subcritical systems using UO
, as well as in applications such as medical physics. This review examines the current state of (
) yield calculations and neutron spectra, describes the computational tools used for their estimation, and discusses the available cross-section data. We investigate the uncertainties affecting (
) yield estimations and propose strategies to enhance their accuracy. Furthermore, we highlight the need for new measurements of (
) cross-sections for a variety of relevant materials. Such measurements are key to improving neutron flux predictions and reducing uncertainties in sensitivity estimates for next-generation physics experiments operating in the keV–MeV range.
The following article is
Open access
Physics beyond colliders at CERN: beyond the Standard Model working group report
J Beacham
et al
2020
J. Phys. G: Nucl. Part. Phys.
47
010501
View article
, Physics beyond colliders at CERN: beyond the Standard Model working group report
PDF
, Physics beyond colliders at CERN: beyond the Standard Model working group report
The Physics Beyond Colliders initiative is an exploratory study aimed at exploiting the full scientific potential of the CERN’s accelerator complex and scientific infrastructures through projects complementary to the LHC and other possible future colliders. These projects will target fundamental physics questions in modern particle physics. This document presents the status of the proposals presented in the framework of the Beyond Standard Model physics working group, and explore their physics reach and the impact that CERN could have in the next 10–20 years on the international landscape.
The following article is
Open access
The Forward Physics Facility at the High-Luminosity LHC
Jonathan L Feng
et al
2023
J. Phys. G: Nucl. Part. Phys.
50
030501
View article
, The Forward Physics Facility at the High-Luminosity LHC
PDF
, The Forward Physics Facility at the High-Luminosity LHC
High energy collisions at the High-Luminosity Large Hadron Collider (LHC) produce a large number of particles along the beam collision axis, outside of the acceptance of existing LHC experiments. The proposed Forward Physics Facility (FPF), to be located several hundred meters from the ATLAS interaction point and shielded by concrete and rock, will host a suite of experiments to probe standard model (SM) processes and search for physics beyond the standard model (BSM). In this report, we review the status of the civil engineering plans and the experiments to explore the diverse physics signals that can be uniquely probed in the forward region. FPF experiments will be sensitive to a broad range of BSM physics through searches for new particle scattering or decay signatures and deviations from SM expectations in high statistics analyses with TeV neutrinos in this low-background environment. High statistics neutrino detection will also provide valuable data for fundamental topics in perturbative and non-perturbative QCD and in weak interactions. Experiments at the FPF will enable synergies between forward particle production at the LHC and astroparticle physics to be exploited. We report here on these physics topics, on infrastructure, detector, and simulation studies, and on future directions to realize the FPF’s physics potential.
The following article is
Open access
White paper on light sterile neutrino searches and related phenomenology
M A Acero
et al
2024
J. Phys. G: Nucl. Part. Phys.
51
120501
View article
, White paper on light sterile neutrino searches and related phenomenology
PDF
, White paper on light sterile neutrino searches and related phenomenology
The following article is
Open access
Letter of intent for KM3NeT 2.0
S Adrián-Martínez
et al
2016
J. Phys. G: Nucl. Part. Phys.
43
084001
View article
, Letter of intent for KM3NeT 2.0
PDF
, Letter of intent for KM3NeT 2.0
The main objectives of the KM3NeT Collaboration are (i) the discovery and subsequent observation of high-energy neutrino sources in the Universe and (ii) the determination of the mass hierarchy of neutrinos. These objectives are strongly motivated by two recent important discoveries, namely: (1) the high-energy astrophysical neutrino signal reported by IceCube and (2) the sizable contribution of electron neutrinos to the third neutrino mass eigenstate as reported by Daya Bay, Reno and others. To meet these objectives, the KM3NeT Collaboration plans to build a new Research Infrastructure consisting of a network of deep-sea neutrino telescopes in the Mediterranean Sea. A phased and distributed implementation is pursued which maximises the access to regional funds, the availability of human resources and the synergistic opportunities for the Earth and sea sciences community. Three suitable deep-sea sites are selected, namely off-shore Toulon (France), Capo Passero (Sicily, Italy) and Pylos (Peloponnese, Greece). The infrastructure will consist of three so-called building blocks. A building block comprises 115 strings, each string comprises 18 optical modules and each optical module comprises 31 photo-multiplier tubes. Each building block thus constitutes a three-dimensional array of photo sensors that can be used to detect the Cherenkov light produced by relativistic particles emerging from neutrino interactions. Two building blocks will be sparsely configured to fully explore the IceCube signal with similar instrumented volume, different methodology, improved resolution and complementary field of view, including the galactic plane. One building block will be densely configured to precisely measure atmospheric neutrino oscillations.
The following article is
Open access
The Large Hadron–Electron Collider at the HL-LHC
P Agostini
et al
2021
J. Phys. G: Nucl. Part. Phys.
48
110501
View article
, The Large Hadron–Electron Collider at the HL-LHC
PDF
, The Large Hadron–Electron Collider at the HL-LHC
The Large Hadron–Electron Collider (LHeC) is designed to move the field of deep inelastic scattering (DIS) to the energy and intensity frontier of particle physics. Exploiting energy-recovery technology, it collides a novel, intense electron beam with a proton or ion beam from the High-Luminosity Large Hadron Collider (HL-LHC). The accelerator and interaction region are designed for concurrent electron–proton and proton–proton operations. This report represents an update to the LHeC’s conceptual design report (CDR), published in 2012. It comprises new results on the parton structure of the proton and heavier nuclei, QCD dynamics, and electroweak and top-quark physics. It is shown how the LHeC will open a new chapter of nuclear particle physics by extending the accessible kinematic range of lepton–nucleus scattering by several orders of magnitude. Due to its enhanced luminosity and large energy and the cleanliness of the final hadronic states, the LHeC has a strong Higgs physics programme and its own discovery potential for new physics. Building on the 2012 CDR, this report contains a detailed updated design for the energy-recovery electron linac (ERL), including a new lattice, magnet and superconducting radio-frequency technology, and further components. Challenges of energy recovery are described, and the lower-energy, high-current, three-turn ERL facility, PERLE at Orsay, is presented, which uses the LHeC characteristics serving as a development facility for the design and operation of the LHeC. An updated detector design is presented corresponding to the acceptance, resolution, and calibration goals that arise from the Higgs and parton-density-function physics programmes. This paper also presents novel results for the Future Circular Collider in electron–hadron (FCC-eh) mode, which utilises the same ERL technology to further extend the reach of DIS to even higher centre-of-mass energies.
The following article is
Open access
False vacuum decay: an introductory review
Federica Devoto
et al
2022
J. Phys. G: Nucl. Part. Phys.
49
103001
View article
, False vacuum decay: an introductory review
PDF
, False vacuum decay: an introductory review
We review the description of tunnelling phenomena in the semi-classical approximation in ordinary quantum mechanics and in quantum field theory. In particular, we describe in detail the calculation, up to the first quantum corrections, of the decay probability per unit time of a metastable ground state. We apply the relevant formalism to the case of the standard model of electroweak interactions, whose ground state is metastable for sufficiently large values of the top quark mass. Finally, we discuss the impact of gravitational interactions on the calculation of the tunnelling rate.
The following article is
Open access
Time integration for neutrino radiation transport using minimally implicit Runge–Kutta methods
Samuel Santos-Pérez
et al
2026
J. Phys. G: Nucl. Part. Phys.
53
045201
View article
, Time integration for neutrino radiation transport using minimally implicit Runge–Kutta methods
PDF
, Time integration for neutrino radiation transport using minimally implicit Runge–Kutta methods
The evolution of many astrophysical systems is dominated by the interaction between matter and radiation such as photons or neutrinos. The dynamics can be described by the evolution equations of radiation hydrodynamics in which reactions between matter particles and radiation quanta couples the hydrodynamic equations to those of radiative transfer (see Munier and Weaver 1986a
Comput. Phys. Rep.
127; 1986b
Comput. Phys. Rep.
165). The numerical treatment has to account for their potential stiffness (e.g. in optically thick environments). In this article, we will present a new method to numerically integrate these equations in a stable way by using minimally implicit Runge–Kutta methods. With these methods, the inversion of the implicit operator can be done analytically, so the computational cost is equivalent to that of an explicit method. In deriving the methods, we explicitly account for the behaviour of the evolved variables in the stiff regime. We will show the results of applying these methods to the reactions between neutrinos and matter in some tests and also in realistic core-collapse supernovae simulations.
The following article is
Open access
LEP3: a high-luminosity
Higgs and electroweak factory in the LHC tunnel
C Anastopoulos
et al
2026
J. Phys. G: Nucl. Part. Phys.
53
040501
View article
, LEP3: a high-luminosity e+e− Higgs and electroweak factory in the LHC tunnel
PDF
, LEP3: a high-luminosity e+e− Higgs and electroweak factory in the LHC tunnel
The 2020 European Strategy for Particle Physics (ESPP) emphasized the critical importance of completing the high-luminosity LHC (HL-LHC) upgrade of both the accelerator and experiments in a timely manner, identifying it as a top priority for the field. The strategy also established two key recommendations for future accelerator initiatives: (i) the realization of an electron–positron Higgs factory as the highest-priority next collider, and (ii) the investigation, in collaboration with international partners, of the technical and financial feasibility of a hadron collider at CERN with a centre-of-mass energy of at least 100 TeV, potentially preceded by an electron–positron Higgs and electroweak factory. In alignment with these objectives, the Future Circular Collider (FCC) programme—comprising FCC-ee and FCC-hh—represents the preferred path forward for CERN, offering both precision and energy-frontier capabilities. However, the 2025 ESPP update calls for the identification of prioritized alternative options should the preferred FCC pathway prove infeasible or non-competitive. In this context, we propose LEP3, an electron–positron collider reusing the existing LHC tunnel, as a strategic backup to FCC-ee. LEP3 would exploit much of the research and development already carried out for FCC-ee, enabling high-precision studies of the Z, W, and Higgs bosons below the top–antitop production threshold. Combining strong physics potential with reduced cost, LEP3 provides performance comparable or superior to other fallback options—such as linear, muon, or LHeC colliders—while maintaining the technological continuity essential for a future energy-frontier collider. Conceived as a contingency, LEP3 complements, rather than competes with, the FCC-ee proposal.
Investigation of proton halo structures in exotic nuclei using the complex momentum representation method
Li-Na Gao and Jian-You Guo 2026
J. Phys. G: Nucl. Part. Phys.
53
045102
View article
, Investigation of proton halo structures in exotic nuclei using the complex momentum representation method
PDF
, Investigation of proton halo structures in exotic nuclei using the complex momentum representation method
The complex momentum representation (CMR) method-offering a unified framework for bound, resonant, and continuum states-was employed to investigate proton halos in exotic nuclei. It successfully reproduced the proton halo structures of
17
F’s first excited state and the ground states of
26
P,
27
P, and
28
P, closely matching results from the shooting method (Ni
et al
2017
Chin. Phys.
41
95). Incorporating the latest experimental proton separation energy (90 ± 10 keV) (Yu
et al
2024
Phys. Rev. Lett.
133
222501), theoretical analysis confirms that
22
Al’s ground state lacks proton halo features. Furthermore, this study leverages CMR to predict, for the first time, proton halo structures in
25
Al’s excited state (via
5/2
1/2
excitation) and the ground states of
56
Cu and
57
Cu. These candidates exhibit ultra-low proton binding energies, significantly expanded root-mean-square radii relative to core protons, and pronounced long-tail density distributions. This work demonstrates CMR’s efficacy in handling continuum problems, providing a robust theoretical tool for exploring exotic nuclei near the drip lines.
The following article is
Open access
WIMP dark matter within the dark photon portal
Xuan-Gong Wang
et al
2026
J. Phys. G: Nucl. Part. Phys.
53
045001
View article
, WIMP dark matter within the dark photon portal
PDF
, WIMP dark matter within the dark photon portal
We test the dark photon as a portal connecting to the dark sector in the case of Dirac fermion and complex scalar dark matter (DM) with masses up to 1 TeV. Both the dark photon and the
boson contribute to the DM annihilation and DM–nucleon scattering processes. We derive the lower limits on the dark parameters from thermal relic density. The corresponding spin-independent DM–proton cross sections are compared with the upper bounds set by direct detection. We explore the allowed regions of the dark parameter space that are consistent with these constraints.
Search for exotic solar neutrino–electron interactions in dark matter direct detection experiment
X. P. Geng
et al
2026
J. Phys. G: Nucl. Part. Phys.
53
045002
View article
, Search for exotic solar neutrino–electron interactions in dark matter direct detection experiment
PDF
, Search for exotic solar neutrino–electron interactions in dark matter direct detection experiment
We probe two attractive exotic solar neutrino–electron signals involving both the active neutrino and the sterile neutrino oscillated from the solar neutrino flux. For the scenario of active neutrino, a new gauge boson under a
(1)
gauge symmetry enhances the interaction between the active neutrino and the Standard Model (SM) particles. For the scenario of sterile neutrino, the dark photon which kinetically mixes with the SM photon introduces a detectable interaction between the sterile neutrino and the SM particles. We improve the most stringent constraints on these two scenarios among the particle physics experiments using the public XENONnT’s 1.16 tonne year electronic recoil dataset, and set the most sensitive laboratory constraints on the sterile-neutrino scenario considered in this work. New parameter space of the ultra-light dark photon is probed under the exotic sterile neutrino model in this work, providing complementary coverage to existing dark photon direct detection searches.
The following article is
Open access
Review of neutron yield from (
) reactions: data, methods, and prospects
D Cano-Ott
et al
2026
J. Phys. G: Nucl. Part. Phys.
53
023001
View article
, Review of neutron yield from (α, n) reactions: data, methods, and prospects
PDF
, Review of neutron yield from (α, n) reactions: data, methods, and prospects
Understanding the radiogenic neutron production rate from the (
) reaction is crucial in many areas of physics, including dark matter searches, neutrino studies, and nuclear astrophysics. In addition to its relevance for fundamental research, the (
) reaction also plays a significant role in nuclear energy technologies, for example by contributing to neutron production in subcritical systems using UO
, as well as in applications such as medical physics. This review examines the current state of (
) yield calculations and neutron spectra, describes the computational tools used for their estimation, and discusses the available cross-section data. We investigate the uncertainties affecting (
) yield estimations and propose strategies to enhance their accuracy. Furthermore, we highlight the need for new measurements of (
) cross-sections for a variety of relevant materials. Such measurements are key to improving neutron flux predictions and reducing uncertainties in sensitivity estimates for next-generation physics experiments operating in the keV–MeV range.
The following article is
Open access
Paths to superheavy nuclei
K Godbey
et al
2025
J. Phys. G: Nucl. Part. Phys.
52
120501
View article
, Paths to superheavy nuclei
PDF
, Paths to superheavy nuclei
This document summarizes the discussions and outcomes of the Facility for Rare Isotope Beams (FRIB) Theory Alliance topical program ‘The path to Superheavy Isotopes’ held in June 2024 at FRIB. Its content is non-exhaustive, reflecting topics chosen and discussed by the participants. The program aimed to assess the current status of theory in superheavy nuclei (SHN) research and identify necessary theoretical developments to guide experimental programs and determine fruitful production mechanisms. This report details the intersection of SHN research with other fields, provides an overview of production mechanisms and theoretical models, discusses future needs in theory and experiment, explores other potential avenues for SHN synthesis, and highlights the importance of building a strong theory community in this area.
The following article is
Open access
Kaon physics: a cornerstone for future discoveries
Jason Aebischer
et al
2025
J. Phys. G: Nucl. Part. Phys.
52
100501
View article
, Kaon physics: a cornerstone for future discoveries
PDF
, Kaon physics: a cornerstone for future discoveries
The kaon physics programme, long heralded as a cutting-edge frontier by the European Strategy for Particle Physics, continues to stand at the intersection of discovery and innovation in high-energy physics (HEP). With its unparalleled capacity to explore new physics at the multi-TeV scale, kaon research is poised to unveil phenomena that could reshape our understanding of the Universe. This document highlights the compelling physics case, with emphasis on exciting new opportunities for advancing kaon physics not only in Europe but also on a global stage. As an important player in the future of HEP, the kaon programme promises to drive transformative breakthroughs, inviting exploration at the forefront of scientific discovery.
The following article is
Open access
Genetic programming for the nuclear many-body problem: a guide
Illya Bakurov
et al
2025
J. Phys. G: Nucl. Part. Phys.
52
102001
View article
, Genetic programming for the nuclear many-body problem: a guide
PDF
, Genetic programming for the nuclear many-body problem: a guide
Genetic Programming (GP) is an evolutionary algorithm that generates computer programs, or mathematical expressions, to solve complex problems. In this Guide, we demonstrate how to use GP to develop surrogate models to mitigate the computational costs of modeling atomic nuclei with ever increasing complexity. The computational burden escalates when uncertainty quantification is pursued, or when observables must be globally computed for thousands of nuclei. By studying three models in which the mean field depends on the total particle density self-consistently, we show that by constructing reduced order models supported by GP one can speed up many-body computations by several orders of magnitude with a negligible loss in accuracy.
The following article is
Open access
Baryon number violation: from nuclear matrix elements to BSM physics
Leah J Broussard
et al
2025
J. Phys. G: Nucl. Part. Phys.
52
083001
View article
, Baryon number violation: from nuclear matrix elements to BSM physics
PDF
, Baryon number violation: from nuclear matrix elements to BSM physics
Processes that violate baryon number, most notably proton decay and
transitions, are promising probes of physics beyond the Standard Model (BSM) needed to understand the lack of antimatter in the Universe. To interpret current and forthcoming experimental limits, theory input from nuclear matrix elements to UV complete models enters. Thus, an interplay of experiment, effective field theory, lattice QCD, and BSM model building is required to develop strategies to accurately extract information from current and future data and maximize the impact and sensitivity of next-generation experiments. Here, we briefly summarize the main results and discussions from the workshop ‘INT-25-91W: Baryon Number Violation: From Nuclear Matrix Elements to BSM Physics,’ held at the Institute for Nuclear Theory, University of Washington, Seattle, WA, 13–17 January 2025.
Amplifying muon-to-positron conversion in nuclei with ultralight dark matter
Sen et al
View accepted manuscript
, Amplifying muon-to-positron conversion in nuclei with ultralight dark matter
PDF
, Amplifying muon-to-positron conversion in nuclei with ultralight dark matter
We present an analysis of the lepton-number and lepton-flavour-violating process of muon-to-positron conversion μ
+ N → e
+ N' , in the presence of an ultralight scalar dark matter (ULSDM) field which couples to neutrinos. The ULSDM contributes to the effective off-diagonal Majorana mass m
µe
, therefore amplifying the rate of muon-to-positron conversion to experimentally observable levels. Using existing bounds from SINDRUM II, COMET, and Mu2e experiments, we derive novel constraints on the flavour-off-diagonal couplings of neutrinos to ULSDM. Our work reveals that upcoming experiments can provide stronger sensitivity to these new couplings than bounds arising from cosmological surveys and terrestrial experiments.
Leptonic originated high-energy neutrinos from astrophysical objects
Bhadra et al
View accepted manuscript
, Leptonic originated high-energy neutrinos from astrophysical objects
PDF
, Leptonic originated high-energy neutrinos from astrophysical objects
High-energy neutrinos are frequently regarded as signatures of hadronic cosmic rays in astrophysical environments. In this work, our modeling suggests that TeV neutrinos could potentially be produced by energetic electrons through electromagnetic processes in certain cosmic-ray accelerators. Under specific parameter spaces, the resulting fluxes appear comparable to those expected from hadronic interactions, indicating that electrons may contribute to the neutrino signals detected by the IceCube Observatory. These findings suggest a potential expansion of the conventional interpretation of neutrino origins and highlight the utility of joint gamma-ray and neutrino observations to help discriminate between hadronic and leptonic production mechanisms.
Spin-parity effects in nuclear binding energies with a hybrid DFT-machine learning framework
Jalili et al
View accepted manuscript
, Spin-parity effects in nuclear binding energies with a hybrid DFT-machine learning framework
PDF
, Spin-parity effects in nuclear binding energies with a hybrid DFT-machine learning framework
We present a hybrid framework that integrates nuclear density functional theory with machine learning to investigate spin-parity effects in nuclear binding energies. Our approach employs a Skyrme energy density functional augmented with isospin-symmetry breaking terms calibrated through analysis of mirror displacement energies. The machine learning component utilizes a multi-layer neural network architecture that learns the mapping between mean-field quantities and their symmetry-restored counterparts after angular-momentum and isospin projection. Our analysis reveals sensitivity to nucleon spin-parity alignments, with the symmetric K02 (aligned) configuration demonstrating improved predictive performance (RMSE = 0.26 MeV) compared to the anti-aligned K01 arrangement (RMSE = 0.31 MeV) when benchmarked against AME2020 experimental data. The framework exhibits reasonable extrapolation capabilities for nuclear mass predictions across the nuclear chart, showing performance comparable to established theoretical models including DZ28, FRDM2012, HFB25, WS, WS3, and WS4. The model reproduces mirror displacement energies with typical deviations below 0.3 MeV for most cases, although some discrepancies persist, indicating that isospin-symmetry breaking effects are not yet fully captured in all regions. This work demonstrates the potential of combining nuclear theory with physics-informed machine learning for nuclear mass predictions, while also highlighting areas where further theoretical development is needed.
Finite-size behavior of higher-order cumulant ratios near criticality in two-dimensional Potts models
Gavai et al
View accepted manuscript
, Finite-size behavior of higher-order cumulant ratios near criticality in two-dimensional Potts models
PDF
, Finite-size behavior of higher-order cumulant ratios near criticality in two-dimensional Potts models
Theoretical considerations predict a specific hierarchy among ratios of net-baryon number cumulants (
, where n is the order of cumulant) in the vicinity of the transition from the low-temperature hadronic phase to the high temperature quark-gluon plasma phase at small baryon chemical potential,
, in the QCD phase diagram. This hierarchy,
, has been observed by the STAR experiment in net-proton number (a proxy of net-baryon number) cumulant ratios over a broad range of collision energies. Motivated by these findings, we investigate whether similar ordering emerges generically in finite statistical systems undergoing second-order phase transitions. We employ two different spin models: the two-state and three-state Potts models in two dimensions, both exhibiting a transition from an ordered phase to a disordered phase at their respective critical temperatures. Monte Carlo simulations are performed on square lattices of varying sizes using the Wolff cluster algorithm. Cumulants of the total magnetization are calculated up to sixth order in both of these models in a temperature range near their corresponding critical temperatures. Higher-order cumulants exhibit extrema (peaks/troughs) whose magnitudes grow with both cumulant order and lattice size, reflecting enhanced critical fluctuations. Except within a narrow temperature window above the critical temperature, neither the complete hierarchy nor its exact reverse is realized over the studied temperature range in either model.
Theoretical analysis of collective band structures in odd-mass
117-125
Cs isotopes
Gupta et al
View accepted manuscript
, Theoretical analysis of collective band structures in odd-mass 117-125Cs isotopes
PDF
, Theoretical analysis of collective band structures in odd-mass 117-125Cs isotopes
The Triaxial Projected Shell Model (TPSM) is employed for a comprehensive theoretical analysis of collective band structures in neutron-deficient, odd-mass caesium isotopes ranging from A = 117 to 125. The TPSM uses a triaxially deformed Nilsson potential combined with angular momentum projection to construct one-quasiparticle and three-quasiparticle configurations. Analysis of band diagrams, nuclear moments of inertia, and energy level systematics reveals good overall agreement between TPSM calculations and experimental data. Our calculations consistently utilise a large triaxial deformation of γ ∼ 30 • , a value validated against the γ-bandhead energies, to accurately reproduce the observed alignment frequencies and signature splitting for these isotopes. Consequently, the findings validate the necessity of a large triaxial description for these complex transitional nuclei.
More Accepted manuscripts
The following article is
Open access
Time integration for neutrino radiation transport using minimally implicit Runge–Kutta methods
Samuel Santos-Pérez
et al
2026
J. Phys. G: Nucl. Part. Phys.
53
045201
View article
, Time integration for neutrino radiation transport using minimally implicit Runge–Kutta methods
PDF
, Time integration for neutrino radiation transport using minimally implicit Runge–Kutta methods
The evolution of many astrophysical systems is dominated by the interaction between matter and radiation such as photons or neutrinos. The dynamics can be described by the evolution equations of radiation hydrodynamics in which reactions between matter particles and radiation quanta couples the hydrodynamic equations to those of radiative transfer (see Munier and Weaver 1986a
Comput. Phys. Rep.
127; 1986b
Comput. Phys. Rep.
165). The numerical treatment has to account for their potential stiffness (e.g. in optically thick environments). In this article, we will present a new method to numerically integrate these equations in a stable way by using minimally implicit Runge–Kutta methods. With these methods, the inversion of the implicit operator can be done analytically, so the computational cost is equivalent to that of an explicit method. In deriving the methods, we explicitly account for the behaviour of the evolved variables in the stiff regime. We will show the results of applying these methods to the reactions between neutrinos and matter in some tests and also in realistic core-collapse supernovae simulations.
The following article is
Open access
LEP3: a high-luminosity
Higgs and electroweak factory in the LHC tunnel
C Anastopoulos
et al
2026
J. Phys. G: Nucl. Part. Phys.
53
040501
View article
, LEP3: a high-luminosity e+e− Higgs and electroweak factory in the LHC tunnel
PDF
, LEP3: a high-luminosity e+e− Higgs and electroweak factory in the LHC tunnel
The 2020 European Strategy for Particle Physics (ESPP) emphasized the critical importance of completing the high-luminosity LHC (HL-LHC) upgrade of both the accelerator and experiments in a timely manner, identifying it as a top priority for the field. The strategy also established two key recommendations for future accelerator initiatives: (i) the realization of an electron–positron Higgs factory as the highest-priority next collider, and (ii) the investigation, in collaboration with international partners, of the technical and financial feasibility of a hadron collider at CERN with a centre-of-mass energy of at least 100 TeV, potentially preceded by an electron–positron Higgs and electroweak factory. In alignment with these objectives, the Future Circular Collider (FCC) programme—comprising FCC-ee and FCC-hh—represents the preferred path forward for CERN, offering both precision and energy-frontier capabilities. However, the 2025 ESPP update calls for the identification of prioritized alternative options should the preferred FCC pathway prove infeasible or non-competitive. In this context, we propose LEP3, an electron–positron collider reusing the existing LHC tunnel, as a strategic backup to FCC-ee. LEP3 would exploit much of the research and development already carried out for FCC-ee, enabling high-precision studies of the Z, W, and Higgs bosons below the top–antitop production threshold. Combining strong physics potential with reduced cost, LEP3 provides performance comparable or superior to other fallback options—such as linear, muon, or LHeC colliders—while maintaining the technological continuity essential for a future energy-frontier collider. Conceived as a contingency, LEP3 complements, rather than competes with, the FCC-ee proposal.
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Isobar separation of actinides in mass spectrometry by the combination of laser photodetachment with ion-gas interactions
Andreas Wiederin
et al
2026
J. Phys. G: Nucl. Part. Phys.
View article
, Isobar separation of actinides in mass spectrometry by the combination of laser photodetachment with ion-gas interactions
PDF
, Isobar separation of actinides in mass spectrometry by the combination of laser photodetachment with ion-gas interactions
Isobaric interference is a major limitation of mass spectrometric measurements of trace radionuclides. For Accelerator Mass Spectrometry (AMS), isobaric separation is only available up to the mass range of fission products. The present work explores the potential of Ion-Laser InterAction Mass Spectrometry (ILIAMS) for trace analysis of anthropogenic actinides with isobaric interference. Such capabilities are crucial for characterizing a highly sought-after isotopic spike material for
237
Np measurements and for accessing additional anthropogenic actinides with AMS, which could serve as environmental tracers, emission source signatures, or for determining the age of nuclear materials. ILIAMS is a novel low-energy isobar separation technique that combines a gas-filled ion cooler with reactive gases or high-power lasers to suppress isobars selectively. In this study, we demonstrate that UF
can be selectively suppressed by two orders of magnitude using a 637 nm laser without affecting NpF
. Initial results indicate the potential for the selective suppression of AmF
to measure PuF
or, in reverse, the suppression of PuF
to measure AmF
using a 355 nm laser. The admixture of O
with the buffer gas of the ion cooler can be used to suppress UF
by up to seven and NpF
by up to three orders of magnitude against PuF
. The first application of these separation schemes for the characterization of a prototype
236
Np spike demonstrated the successful chemical removal of the co-produced isobars
236
U and
236
Pu, and similar measurements can now be performed for other prospective Np spike materials. The isobar separation schemes developed here can also enable the measurement of
241
Pu without chemically removing
241
Am or
242m
Am in the presence of
242
Pu. Even measuring
238
Pu using AMS has become feasible for suitable sample matrices, despite the presence of the primordial isobar
238
U. These are important isotopic signatures for attributing environmental contamination to potential sources of emissions.
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The Sherman function and its radiative corrections for the elastic scattering of positrons from spin-zero nuclei
Doris H Jakubassa-Amundsen 2026
J. Phys. G: Nucl. Part. Phys.
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, The Sherman function and its radiative corrections for the elastic scattering of positrons from spin-zero nuclei
PDF
, The Sherman function and its radiative corrections for the elastic scattering of positrons from spin-zero nuclei
The beam-normal spin asymmetry S from the scattering of spin-polarized positrons is estimated by means of the phase-shift analysis. A nonperturbative inclusion of quantum electrodynamical (QED) effects leads to modifications of S in the percent region for collision energies above 20 MeV. Second-order Born predictions for the dispersive corrections are also made by considering the dominant low-lying nuclear excitations. As examples, the 12C and 208Pb target nuclei are studied, predominantly for collision energies up to the pion production threshold. The comparison with results from electron scattering shows that the influence of the Coulomb distortion is, in contrast to 12C, very significant for 208Pb.
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WIMP dark matter within the dark photon portal
Xuan-Gong Wang
et al
2026
J. Phys. G: Nucl. Part. Phys.
53
045001
View article
, WIMP dark matter within the dark photon portal
PDF
, WIMP dark matter within the dark photon portal
We test the dark photon as a portal connecting to the dark sector in the case of Dirac fermion and complex scalar dark matter (DM) with masses up to 1 TeV. Both the dark photon and the
boson contribute to the DM annihilation and DM–nucleon scattering processes. We derive the lower limits on the dark parameters from thermal relic density. The corresponding spin-independent DM–proton cross sections are compared with the upper bounds set by direct detection. We explore the allowed regions of the dark parameter space that are consistent with these constraints.
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Search for double-electron capture in
152
Gd with GAGG:Ce scintillator
P Belli
et al
2026
J. Phys. G: Nucl. Part. Phys.
53
045101
View article
, Search for double-electron capture in 152Gd with GAGG:Ce scintillator
PDF
, Search for double-electron capture in 152Gd with GAGG:Ce scintillator
Double-electron capture in
152
Gd was searched for over 1336 h with a 286 g GAGG:Ce crystal scintillator at the Gran Sasso underground laboratory of the INFN (Italy). New, improved by four orders of magnitude, limit on the near-resonant 0
2EC capture in
152
Gd was set as
year at 90% C.L. Moreover, for the first time, a laboratory experiment has established a lower limit on the half-life of the allowed 2
KL process in the nuclide, with
year at 90% C.L.
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Inverse magnetic catalysis in the linear sigma model: a beyond mean field approach
Gabriela Fernández
et al
2026
J. Phys. G: Nucl. Part. Phys.
53
035001
View article
, Inverse magnetic catalysis in the linear sigma model: a beyond mean field approach
PDF
, Inverse magnetic catalysis in the linear sigma model: a beyond mean field approach
We explore the restoration of chiral symmetry in the linear sigma model coupled to quarks under the influence of strong magnetic fields and finite temperature, incorporating screening effects through ring diagrams. While previous studies using tree-level thermal masses lead to magnetic catalysis (MC) across all temperature ranges, in tension with lattice quantum chromodynamics (QCD) results, we go beyond this limitation by computing the bosonic masses self-consistently within the lowest Landau level approximation. The self-consistent approach modifies the effective potential and allows us to accurately track the thermal evolution of the order parameter. Our results reveal the emergence of a critical end point in the
–∣
eB
∣ phase diagram and, notably, exhibit inverse MC behavior: the (pseudo)critical temperature decreases with increasing magnetic field strength. This is in contrast to the MC behavior found when non-self-consistent masses are used. To the best of our knowledge, this is the first time that self-consistent boson masses have been implemented in this context, offering a new framework for exploring the QCD phase diagram using effective models.
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Review of neutron yield from (
) reactions: data, methods, and prospects
D Cano-Ott
et al
2026
J. Phys. G: Nucl. Part. Phys.
53
023001
View article
, Review of neutron yield from (α, n) reactions: data, methods, and prospects
PDF
, Review of neutron yield from (α, n) reactions: data, methods, and prospects
Understanding the radiogenic neutron production rate from the (
) reaction is crucial in many areas of physics, including dark matter searches, neutrino studies, and nuclear astrophysics. In addition to its relevance for fundamental research, the (
) reaction also plays a significant role in nuclear energy technologies, for example by contributing to neutron production in subcritical systems using UO
, as well as in applications such as medical physics. This review examines the current state of (
) yield calculations and neutron spectra, describes the computational tools used for their estimation, and discusses the available cross-section data. We investigate the uncertainties affecting (
) yield estimations and propose strategies to enhance their accuracy. Furthermore, we highlight the need for new measurements of (
) cross-sections for a variety of relevant materials. Such measurements are key to improving neutron flux predictions and reducing uncertainties in sensitivity estimates for next-generation physics experiments operating in the keV–MeV range.
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Coulomb energy differences in
B using a molecular model
AD Brooks
et al
2026
J. Phys. G: Nucl. Part. Phys.
53
025103
View article
, Coulomb energy differences in 9B using a molecular model
PDF
, Coulomb energy differences in 9B using a molecular model
Through the application of a molecular model to band-head states in
B, a prediction of the Coulomb energy difference relative to the 1/2
analogue state in
Be is calculated. Under such treatment, a positive shift in energy of 0.605 MeV is found to emerge from molecular structures defined by replication of experimental rotational-band parameters. Given the relationship between the spatial arrangement of clusters within the nucleus and the obtained Coulomb energy, it is also possible to examine nuclear structures using known Thomas–Ehrman shifts. Molecular structures built using the
separation, 2
, required to give Thomas–Ehrman shifts for both a 1.84 and 0.8 MeV candidate of the
B(1/2
) analogue state (
= 1.89 fm and
= 3.18 fm respectively) are used to calculate state inertial parameters (
). From these structures, it is found that a 1.84 MeV state (
= 0.407 MeV) agrees with the experimental
= 1/2
rotational band inertial parameter (
= 0.41 ± 0.01 MeV) and a 0.8 MeV state does not (
= 0.191 MeV). Thus, due to the large
spacing required to lower the Coulomb energy relative to
Be, the existence of a 0.8 MeV
B(1/2
) analogue state is highly unlikely. Indeed, excitation energies less than ≈1.25 MeV for a 1/2
state, corresponding to a normal Thomas–Ehrman shift, can also be ruled out.
The following article is
Open access
Renormalon-based resummation for spacelike and timelike QCD quantities whose perturbation expansion has general form
César Ayala
et al
2026
J. Phys. G: Nucl. Part. Phys.
53
025005
View article
, Renormalon-based resummation for spacelike and timelike QCD quantities whose perturbation expansion has general form
PDF
, Renormalon-based resummation for spacelike and timelike QCD quantities whose perturbation expansion has general form
We present a generalisation of our previous approach of a renormalon-motivated resummation of the QCD observables. Previously it was applied to the spacelike observables whose perturbation expansion was
, where
) ≡
)/
is the running QCD coupling. Now we generalise the resummation to spacelike quantities
and timelike quantities
, where
is in general a noninteger number (0 <
≤ 1). We evaluate with this approach a timelike quantity, namely the scheme-invariant factor of the Wilson coefficient of the chromomagnetic operator in the heavy-quark effective Lagrangian, and related quantities.
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Primordial black holes as a dark matter candidate
Anne M Green and Bradley J Kavanagh 2021
J. Phys. G: Nucl. Part. Phys.
48
043001
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, Primordial black holes as a dark matter candidate
PDF
, Primordial black holes as a dark matter candidate
The detection of gravitational waves from mergers of tens of Solar mass black hole binaries has led to a surge in interest in primordial black holes (PBHs) as a dark matter candidate. We aim to provide a (relatively) concise overview of the status of PBHs as a dark matter candidate, circa Summer 2020. First we review the formation of PBHs in the early Universe, focussing mainly on PBHs formed via the collapse of large density perturbations generated by inflation. Then we review the various current and future constraints on the present day abundance of PBHs. We conclude with a discussion of the key open questions in this field.
Presentation of search results: the
CL
technique
A L Read 2002
J. Phys. G: Nucl. Part. Phys.
28
2693
View article
, Presentation of search results: the CLs technique
PDF
, Presentation of search results: the CLs technique
I describe a framework for the presentation of search results which is motivated by frequentist statistics. The most well-known use of this framework is for the combined search for the Higgs boson at LEP. A toy neutrino oscillations experiment is used to illustrate the rich information available in the framework for exclusion and discovery. I argue that the so-called
CL
technique for setting limits is appropriate for determining exclusion intervals while the determination of confidence intervals advocated by Feldman and Cousins' method is more appropriate for treating established signals, i.e. going beyond discovery to measurement.
(From the workshop ‘Advanced Statistical Techniques in Particle Physics’, 18–22 March 2002)
The following article is
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Letter of intent for KM3NeT 2.0
S Adrián-Martínez
et al
2016
J. Phys. G: Nucl. Part. Phys.
43
084001
View article
, Letter of intent for KM3NeT 2.0
PDF
, Letter of intent for KM3NeT 2.0
The main objectives of the KM3NeT Collaboration are (i) the discovery and subsequent observation of high-energy neutrino sources in the Universe and (ii) the determination of the mass hierarchy of neutrinos. These objectives are strongly motivated by two recent important discoveries, namely: (1) the high-energy astrophysical neutrino signal reported by IceCube and (2) the sizable contribution of electron neutrinos to the third neutrino mass eigenstate as reported by Daya Bay, Reno and others. To meet these objectives, the KM3NeT Collaboration plans to build a new Research Infrastructure consisting of a network of deep-sea neutrino telescopes in the Mediterranean Sea. A phased and distributed implementation is pursued which maximises the access to regional funds, the availability of human resources and the synergistic opportunities for the Earth and sea sciences community. Three suitable deep-sea sites are selected, namely off-shore Toulon (France), Capo Passero (Sicily, Italy) and Pylos (Peloponnese, Greece). The infrastructure will consist of three so-called building blocks. A building block comprises 115 strings, each string comprises 18 optical modules and each optical module comprises 31 photo-multiplier tubes. Each building block thus constitutes a three-dimensional array of photo sensors that can be used to detect the Cherenkov light produced by relativistic particles emerging from neutrino interactions. Two building blocks will be sparsely configured to fully explore the IceCube signal with similar instrumented volume, different methodology, improved resolution and complementary field of view, including the galactic plane. One building block will be densely configured to precisely measure atmospheric neutrino oscillations.
IceCube-Gen2: the window to the extreme Universe
M G Aartsen
et al
2021
J. Phys. G: Nucl. Part. Phys.
48
060501
View article
, IceCube-Gen2: the window to the extreme Universe
PDF
, IceCube-Gen2: the window to the extreme Universe
The observation of electromagnetic radiation from radio to γ-ray wavelengths has provided a wealth of information about the Universe. However, at PeV (10
15
eV) energies and above, most of the Universe is impenetrable to photons. New messengers, namely cosmic neutrinos, are needed to explore the most extreme environments of the Universe where black holes, neutron stars, and stellar explosions transform gravitational energy into non-thermal cosmic rays. These energetic particles have millions of times higher energies than those produced in the most powerful particle accelerators on Earth. As neutrinos can escape from regions otherwise opaque to radiation, they allow an unique view deep into exploding stars and the vicinity of the event horizons of black holes. The discovery of cosmic neutrinos with IceCube has opened this new window on the Universe. IceCube has been successful in finding first evidence for cosmic particle acceleration in the jet of an active galactic nucleus. Yet, ultimately, its sensitivity is too limited to detect even the brightest neutrino sources with high significance, or to detect populations of less luminous sources. In this white paper, we present an overview of a next-generation instrument, IceCube-Gen2, which will sharpen our understanding of the processes and environments that govern the Universe at the highest energies. IceCube-Gen2 is designed to:
(a) Resolve the high-energy neutrino sky from TeV to EeV energies
(b) Investigate cosmic particle acceleration through multi-messenger observations
(c) Reveal the sources and propagation of the highest energy particles in the Universe
(d) Probe fundamental physics with high-energy neutrinos
IceCube-Gen2 will enhance the existing IceCube detector at the South Pole. It will increase the annual rate of observed cosmic neutrinos by a factor of ten compared to IceCube, and will be able to detect sources five times fainter than its predecessor. Furthermore, through the addition of a radio array, IceCube-Gen2 will extend the energy range by several orders of magnitude compared to IceCube. Construction will take 8 years and cost about $350M. The goal is to have IceCube-Gen2 fully operational by 2033.
IceCube-Gen2 will play an essential role in shaping the new era of multi-messenger astronomy, fundamentally advancing our knowledge of the high-energy Universe. This challenging mission can be fully addressed only through the combination of the information from the neutrino, electromagnetic, and gravitational wave emission of high-energy sources, in concert with the new survey instruments across the electromagnetic spectrum and gravitational wave detectors which will be available in the coming years.
PDF4LHC recommendations for LHC Run II
Jon Butterworth
et al
2016
J. Phys. G: Nucl. Part. Phys.
43
023001
View article
, PDF4LHC recommendations for LHC Run II
PDF
, PDF4LHC recommendations for LHC Run II
We provide an updated recommendation for the usage of sets of parton distribution functions (PDFs) and the assessment of PDF and PDF+
uncertainties suitable for applications at the LHC Run II. We review developments since the previous PDF4LHC recommendation, and discuss and compare the new generation of PDFs, which include substantial information from experimental data from the Run I of the LHC. We then propose a new prescription for the combination of a suitable subset of the available PDF sets, which is presented in terms of a single combined PDF set. We finally discuss tools which allow for the delivery of this combined set in terms of optimized sets of Hessian eigenvectors or Monte Carlo replicas, and their usage, and provide some examples of their application to LHC phenomenology. This paper is dedicated to the memory of Guido Altarelli (1941–2015), whose seminal work made possible the quantitative study of PDFs.
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Physics beyond colliders at CERN: beyond the Standard Model working group report
J Beacham
et al
2020
J. Phys. G: Nucl. Part. Phys.
47
010501
View article
, Physics beyond colliders at CERN: beyond the Standard Model working group report
PDF
, Physics beyond colliders at CERN: beyond the Standard Model working group report
The Physics Beyond Colliders initiative is an exploratory study aimed at exploiting the full scientific potential of the CERN’s accelerator complex and scientific infrastructures through projects complementary to the LHC and other possible future colliders. These projects will target fundamental physics questions in modern particle physics. This document presents the status of the proposals presented in the framework of the Beyond Standard Model physics working group, and explore their physics reach and the impact that CERN could have in the next 10–20 years on the international landscape.
Direct detection of WIMP dark matter: concepts and status
Marc Schumann 2019
J. Phys. G: Nucl. Part. Phys.
46
103003
View article
, Direct detection of WIMP dark matter: concepts and status
PDF
, Direct detection of WIMP dark matter: concepts and status
The existence of dark matter as evidenced by numerous indirect observations is one of the most important indications that there must be physics beyond the Standard Model of particle physics. This article reviews the concepts of direct detection of dark matter in the form of Weakly Interacting Massive Particles in ultra-sensitive detectors located in underground laboratories, discusses the expected signatures, detector concepts, and how the stringent low-background requirements are achieved. Finally, it summarizes the current status of the field and provides an outlook on the years to come.
nEXO: neutrinoless double beta decay search beyond 10
28
year half-life sensitivity
G Adhikari
et al
2022
J. Phys. G: Nucl. Part. Phys.
49
015104
View article
, nEXO: neutrinoless double beta decay search beyond 1028 year half-life sensitivity
PDF
, nEXO: neutrinoless double beta decay search beyond 1028 year half-life sensitivity
The nEXO neutrinoless double beta (0
νββ
) decay experiment is designed to use a time projection chamber and 5000 kg of isotopically enriched liquid xenon to search for the decay in
136
Xe. Progress in the detector design, paired with higher fidelity in its simulation and an advanced data analysis, based on the one used for the final results of EXO-200, produce a sensitivity prediction that exceeds the half-life of 10
28
years. Specifically, improvements have been made in the understanding of production of scintillation photons and charge as well as of their transport and reconstruction in the detector. The more detailed knowledge of the detector construction has been paired with more assays for trace radioactivity in different materials. In particular, the use of custom electroformed copper is now incorporated in the design, leading to a substantial reduction in backgrounds from the intrinsic radioactivity of detector materials. Furthermore, a number of assumptions from previous sensitivity projections have gained further support from interim work validating the nEXO experiment concept. Together these improvements and updates suggest that the nEXO experiment will reach a half-life sensitivity of 1.35 × 10
28
yr at 90% confidence level in 10 years of data taking, covering the parameter space associated with the inverted neutrino mass ordering, along with a significant portion of the parameter space for the normal ordering scenario, for almost all nuclear matrix elements. The effects of backgrounds deviating from the nominal values used for the projections are also illustrated, concluding that the nEXO design is robust against a number of imperfections of the model.
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The Forward Physics Facility at the High-Luminosity LHC
Jonathan L Feng
et al
2023
J. Phys. G: Nucl. Part. Phys.
50
030501
View article
, The Forward Physics Facility at the High-Luminosity LHC
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, The Forward Physics Facility at the High-Luminosity LHC
High energy collisions at the High-Luminosity Large Hadron Collider (LHC) produce a large number of particles along the beam collision axis, outside of the acceptance of existing LHC experiments. The proposed Forward Physics Facility (FPF), to be located several hundred meters from the ATLAS interaction point and shielded by concrete and rock, will host a suite of experiments to probe standard model (SM) processes and search for physics beyond the standard model (BSM). In this report, we review the status of the civil engineering plans and the experiments to explore the diverse physics signals that can be uniquely probed in the forward region. FPF experiments will be sensitive to a broad range of BSM physics through searches for new particle scattering or decay signatures and deviations from SM expectations in high statistics analyses with TeV neutrinos in this low-background environment. High statistics neutrino detection will also provide valuable data for fundamental topics in perturbative and non-perturbative QCD and in weak interactions. Experiments at the FPF will enable synergies between forward particle production at the LHC and astroparticle physics to be exploited. We report here on these physics topics, on infrastructure, detector, and simulation studies, and on future directions to realize the FPF’s physics potential.
The following article is
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The present and future status of heavy neutral leptons
Asli M Abdullahi
et al
2023
J. Phys. G: Nucl. Part. Phys.
50
020501
View article
, The present and future status of heavy neutral leptons
PDF
, The present and future status of heavy neutral leptons
The existence of nonzero neutrino masses points to the likely existence of multiple Standard Model neutral fermions. When such states are heavy enough that they cannot be produced in oscillations, they are referred to as heavy neutral leptons (HNLs). In this white paper, we discuss the present experimental status of HNLs including colliders, beta decay, accelerators, as well as astrophysical and cosmological impacts. We discuss the importance of continuing to search for HNLs, and its potential impact on our understanding of key fundamental questions, and additionally we outline the future prospects for next-generation future experiments or upcoming accelerator run scenarios.
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1989-present
Journal of Physics G: Nuclear and Particle Physics
doi: 10.1088/issn.0954-3899
Online ISSN: 1361-6471
Print ISSN: 0954-3899
Journal history
1989-present
Journal of Physics G: Nuclear and Particle Physics
1975-1988
Journal of Physics G: Nuclear Physics