The field of laser-matter interaction traditionally deals with the response of atoms, molecules, and plasmas to an external light wave. However, the recent sustained technological progress is opening up the possibility of employing intense laser radiation to trigger or substantially influence physical processes beyond atomic-physics energy scales. Available optical laser intensities exceeding ${10}^{22}\text{ }\text{ }\mathrm{W}/{\mathrm{cm}}^{2}$ can push the fundamental light-electron interaction to the extreme limit where radiation-reaction effects dominate the electron dynamics, can shed light on the structure of the quantum vacuum, and can trigger the creation of particles such as electrons, muons, and pions and their corresponding antiparticles. Also, novel sources of intense coherent high-energy photons and laser-based particle colliders can pave the way to nuclear quantum optics and may even allow for the potential discovery of new particles beyond the standard model. These are the main topics of this article, which is devoted to a review of recent investigations on high-energy processes within the realm of relativistic quantum dynamics, quantum electrodynamics, and nuclear and particle physics, occurring in extremely intense laser fields.
Inspired by the well-known experimental connections between <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>X</mi><mo>(</mo><mn>3872</mn><mo>)</mo></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>Z</mi><mrow><mi>c</mi><mi>s</mi></mrow></msub><mrow><mo>(</mo><mn>4220</mn><mo>)</mo></mrow></mrow></semantics></math></inline-formula>, and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Y</mi><mo>(</mo><mn>4620</mn><mo>)</mo></mrow></semantics></math></inline-formula>, we systematically study the recently reported strange partner of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>T</mi><mrow><mi>c</mi><mi>c</mi></mrow></msub></semantics></math></inline-formula>, the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>1</mn><mo>+</mo></msup></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>c</mi><mi>c</mi><mover accent="true"><mi>q</mi><mo>¯</mo></mover><mover accent="true"><mi>s</mi><mo>¯</mo></mover></mrow></semantics></math></inline-formula> system, and its orbital excitation state <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>1</mn><mo>−</mo></msup></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>c</mi><mi>c</mi><mover accent="true"><mi>q</mi><mo>¯</mo></mover><mover accent="true"><mi>s</mi><mo>¯</mo></mover></mrow></semantics></math></inline-formula>. A chiral quark model incorporating SU(3) symmetry is considered to study these two systems. To better investigate their spatial structure, we introduce a precise few-body calculation method, the Gaussian Expansion Method (GEM). In our calculations, we include all possible physical channels, including molecular states and diquark structures, and consider channel coupling effects. To identify the stable structures in the system (bound states and resonance states) we employ a powerful resonance search method, the Real-Scaling Method (RSM). According to our results, in the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>1</mn><mo>+</mo></msup></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>c</mi><mi>c</mi><mover accent="true"><mi>q</mi><mo>¯</mo></mover><mover accent="true"><mi>s</mi><mo>¯</mo></mover></mrow></semantics></math></inline-formula> system, we obtain two bound states with energies of 3890 MeV and 3940 MeV, as well as two resonance states with energies of 3975 MeV and 4090 MeV. The decay channels of these two resonance states are <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>D</mi><msubsup><mi>D</mi><mi>s</mi><mo>∗</mo></msubsup></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>D</mi><mo>∗</mo></msup><msub><mi>D</mi><mi>s</mi></msub></mrow></semantics></math></inline-formula>, respectively. In the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>1</mn><mo>−</mo></msup></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>c</mi><mi>c</mi><mover accent="true"><mi>q</mi><mo>¯</mo></mover><mover accent="true"><mi>s</mi><mo>¯</mo></mover></mrow></semantics></math></inline-formula> system, we obtain only one resonance state, with an energy of 4570 MeV, and two main decay channels: <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>D</mi><msubsup><mi>D</mi><mrow><mi>s</mi><mn>1</mn></mrow><mo>∗</mo></msubsup></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>D</mi><mo>∗</mo></msup><msubsup><mi>D</mi><mrow><mi>s</mi><mn>1</mn></mrow><mo>′</mo></msubsup></mrow></semantics></math></inline-formula>. We strongly suggest that experimental groups use our predictions to search for these stable structures.
Nuclear and particle physics. Atomic energy. Radioactivity
Beta decay is a fundamental process that governs nuclear stability and serves as a sensitive probe of the weak interaction and possible physics beyond the Standard Model of particle physics. However, precise measurements of complete $\beta$ decay spectra, particularly at low energies, remain experimentally and theoretically challenging. Here we report a high-precision, threshold-free measurement of the full $\beta$ decay spectrum of 210Pb to excited states of 210Bi, using a transition-edge sensor (TES)-based micro-calorimeter. This approach enables the detection of $\beta$ particle energies from 0 keV up to their endpoint by coincidence summing with subsequent de-excitation energy, thereby eliminating reconstruction artifacts near zero energy that have traditionally limited low-energy spectral accuracy. To our knowledge, this is the first complete, high-precision $\beta$ decay spectrum from 0 keV. The data resolve theoretical uncertainties associated with the atomic quantum exchange (AQE) effect. An accompanying ab initio theoretical framework, incorporating atomic, leptonic, and nuclear components, predicts a statistically significant (7.2 {$\sigma$}) enhancement in $\beta$ emission probability near zero energy, in agreement with the measurement and in contrast to models that omit AQE corrections. These results provide a new benchmark for $\beta$ decay theory at low energies, deepen our understanding of the weak interaction, and establish a critical foundation for searches for new physics, including dark matter interactions and precision studies of neutrinos.
Poher's theory of universons (gravitational quanta) makes it possible to reconcile general relativity and quantum physics. The universon, responsible for gravitation, could be the only elementary particle, making up electrons and quarks. Based on this new quantum gravitation theory and extrapolating beyond, we propose that: Each electron within the atom is a “cloud” of millions of universons, circulating in an erratic way around the nucleus as a result of constantly interacting with anisotropic flows of universons. The tunneling effect is due to anisotropic fluxes of universons of much higher-than-average energy, giving a particle the additional energy allowing it to cross the potential barrier. Radioactivity results from gravitation, more precisely from random fluctuations within anisotropic fluxes of universons and could be explained without relying on the weak and strong interactions. Considering that universons interact only with subatomic particles (and not directly at the macroscopic/ supra-atomic level), the gravitational interaction at the subatomic level could be much stronger than at the macroscopic level; it could be revised upwards by a huge factor: 1030 for nucleons and between 1032 and 1048 for quarks. Furthermore, within the nucleus, the repulsive force between protons could be weaker if we consider the charges of the d quark (-1⁄3) and u quark (+2⁄3) and not their overall charge +1. Thus, the gravitational interaction revised upwards at the subatomic level could explain the cohesion of nucleons within the atomic nucleus and the cohesion of quarks, without relying on the strong interaction, making gravitation a candidate as the only fundamental interaction. This heuristic approach still needs complementary studies and experimental validation.
Studying alpha decay properties like half-lives, decay energies, reduced alpha decay width, formation probabilities, and neutron shell gaps is vital to identify the shell structure at [Formula: see text]. These factors reveal stability, energy states, decay likelihood, and shell closures, offering insights into nuclear physics and atomic nucleus stability. The behavior of alpha decay energy values along an isotopic chain increases as neutron number increases, peaking at [Formula: see text] and 129 before sharply declining. The alpha decay half-lives become the minimum near [Formula: see text] and 129. This pattern also suggests the presence of a neutron shell closure at N = 126. Alpha decay widths are lowest at [Formula: see text] and highest at [Formula: see text] and 129, reflecting increased nucleon stability near filled shell configurations. As nuclei approach these configurations, the energy barrier for alpha decay rises, resulting in narrower widths. The study of alpha particle formation probability ([Formula: see text]) near the neutron shell closure at [Formula: see text] (within 10 neutrons) reveals a discernible pattern. Below the closure, [Formula: see text] declines with more neutrons until it reaches a minimum at the closure. Crossing the closure triggers a sudden increase in [Formula: see text]. We have predicted the new isotones near [Formula: see text] that can be detected through experiments. This work will certainly be helpful in synthesizing new isotones near [Formula: see text].
K. Trachenko, Bartomeu Monserrat, M. Hutcheon
et al.
Fundamental physical constants govern key effects in high-energy particle physics and astrophysics, including the stability of particles, nuclear reactions, formation and evolution of stars, synthesis of heavy nuclei and emergence of stable molecular structures. Here, we show that fundamental constants also set an upper bound for the frequency of phonons in condensed matter phases, or how rapidly an atom can vibrate in these phases. This bound is in agreement with ab initio simulations of atomic hydrogen and high-temperature hydride superconductors, and implies an upper limit to the superconducting transition temperature Tc in condensed matter. Fundamental constants set this limit to the order of 102–103 K. This range is consistent with our calculations of Tc from optimal Eliashberg functions. As a corollary, we observe that the very existence of the current research of finding Tc at and above 300 K is due to the observed values of fundamental constants. We finally discuss how fundamental constants affect the observability and operation of other effects and phenomena including phase transitions.
Nanotomography with hard X-rays is a widely used technique for high-resolution imaging, providing insights into the structure and composition of various materials. In recent years, tomographic approaches based on simultaneous illuminations of the same sample region from different angles by multiple beams have been developed at micrometre image resolution. Transferring these techniques to the nanoscale is challenging due to the loss in photon flux by focusing the X-ray beam. We present an approach for multi-beam nanotomography using a dual-beam Fresnel zone plate (dFZP) in a near-field holography setup. The dFZP generates two nano-focused beams that overlap in the sample plane, enabling the simultaneous acquisition of two projections from slightly different angles. This first proof-of-principle implementation of the dual-beam setup allows for the efficient removal of ring artifacts and noise using machine-learning approaches. The results open new possibilities for full-field multi-beam nanotomography and pave the way for future advancements in fast holotomography and artifact-reduction techniques.
Nuclear and particle physics. Atomic energy. Radioactivity, Crystallography
Abstract Information about the three-dimensional description of the quark and gluon content of hadrons, described by the generalized parton distributions (GPDs), can be probed by exclusive processes in electron–proton (ep) collisions. In this letter, we investigate the timelike Compton scattering (TCS) in ep collisions at the future electron-ion collider (EIC). Such process is characterized by the exclusive dilepton production through the subprocess $$\gamma p \rightarrow \gamma ^*p \rightarrow l^+ l^- p$$ γ p → γ ∗ p → l + l - p , with the real photon in the initial state being emitted by the incoming electron. Assuming a given model for the GPDs, the TCS differential cross-section is estimated, as well the contribution associated to the interference between the TCS and Bethe–Heitler (BH) amplitudes. Predictions for the TCS, BH and interference contributions are presented considering the kinematical range expected to be covered by the EIC detectors. Moreover, the polarized photon asymmetry is also studied. Our results indicated that a future experimental analysis, considering photon circular polarizations, can be useful to probe the interference contribution and constrain the description of the GPDs for the proton.
Astrophysics, Nuclear and particle physics. Atomic energy. Radioactivity
Ordinary 3D Baryon Acoustic Oscillations (BAO) data are model-dependent, requiring the assumption of a cosmological model to calculate comoving distances during data reduction. Throughout the present-day literature, the assumed model is <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">Λ</mi></semantics></math></inline-formula>CDM. However, it has been pointed out in several recent works that this assumption can be inadequate when analyzing alternative cosmologies, potentially biasing the Hubble constant (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>H</mi><mn>0</mn></msub></semantics></math></inline-formula>) low, thus contributing to the Hubble tension. To address this issue, 3D BAO data can be replaced with 2D BAO data, which are only weakly model-dependent. The impact of using 2D BAO data, in combination with alternative cosmological models beyond <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">Λ</mi></semantics></math></inline-formula>CDM, has been explored for several phenomenological models, showing a promising reduction in the Hubble tension. In this work, we accommodate these models in the theoretically robust framework of bimetric gravity. This is a modified theory of gravity that exhibits a transition from a (possibly) negative cosmological constant in the early universe to a positive one in the late universe. By combining 2D BAO data with cosmic microwave background and type Ia supernovae data, we find that the inverse distance ladder in this theory yields a Hubble constant of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>H</mi><mn>0</mn></msub><mo>=</mo><mrow><mo>(</mo><mn>71.0</mn><mspace width="3.33333pt"></mspace><mo>±</mo><mspace width="3.33333pt"></mspace><mn>0.9</mn><mo>)</mo></mrow><mspace width="0.166667em"></mspace><mi>km</mi><mo>/</mo><mi mathvariant="normal">s</mi><mo>/</mo><mi>Mpc</mi></mrow></semantics></math></inline-formula>, consistent with the SH0ES local distance ladder measurement of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>H</mi><mn>0</mn></msub><mo>=</mo><mrow><mo>(</mo><mn>73.0</mn><mspace width="3.33333pt"></mspace><mo>±</mo><mspace width="3.33333pt"></mspace><mn>1.0</mn><mo>)</mo></mrow><mspace width="0.166667em"></mspace><mi>km</mi><mo>/</mo><mi mathvariant="normal">s</mi><mo>/</mo><mi>Mpc</mi></mrow></semantics></math></inline-formula>. Replacing 2D BAO with 3D BAO results in <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>H</mi><mn>0</mn></msub><mo>=</mo><mrow><mo>(</mo><mn>68.6</mn><mspace width="3.33333pt"></mspace><mo>±</mo><mspace width="3.33333pt"></mspace><mn>0.5</mn><mo>)</mo></mrow><mspace width="0.166667em"></mspace><mi>km</mi><mo>/</mo><mi mathvariant="normal">s</mi><mo>/</mo><mi>Mpc</mi></mrow></semantics></math></inline-formula> from the inverse distance ladder. We conclude that the choice of BAO data significantly impacts the Hubble tension, with ordinary 3D BAO data exacerbating the tension, while 2D BAO data provide results consistent with the local distance ladder.
Abstract We compute the effects due to the virtual exchange (or the soft emission) of a scalar particle with generic couplings to the top quark in t t ¯ $$ t\overline{t} $$ pair production at the LHC. We apply the results to two cases of interest, extending and completing previous studies. First, we consider the indirect search for light (m S < 2m t ) top-philic scalars with CP-even and/or CP-odd interactions. Second, we investigate how to set constraints on anomalous Yukawa couplings of the Higgs boson to the top quark. Our results show that the current precision of experimental data together with the accuracy of the SM predictions make such indirect determinations a powerful probe for new physics.
Nuclear and particle physics. Atomic energy. Radioactivity
The studies for the interaction of energetic particles with matter have greatly contributed to the exploration of material properties under irradiation conditions, such as nuclear safety, medical physics and aerospace applications. In this work, we theoretically simulate the non-adiabatic process for GaAs upon proton irradiation using time-dependent density functional theory, and find that the radial propagation of force on atoms and the excitation of electron in GaAs are non-synchronous process. We calculated the electronic stopping power on proton with the velocity of 0.1–0.6 a.u., agreement with the previous empirical results. After further analyzing the force on atoms and the population of excited electrons, we find that under proton irradiation, the electrons around the host atoms at different distances from the proton trajectories are excited almost simultaneously, especially those regions with relatively high charge density. However, the distant atoms have a significant hysteresis in force, which occurs after the surrounding electrons are excited. In addition, hysteresis in force and electron excitation behavior at different positions are closely related to the velocity of proton. This non-synchronous propagation reveals the microscopic dynamic mechanism of energy deposition into the target material under ion irradiation.
Muhammad Waqas, Atef AbdelKader, Muhammad Ajaz
et al.
We analyzed the transverse momentum spectra (<inline-formula><math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><msub><mi>p</mi><mi>T</mi></msub></semantics></math></inline-formula>) reported by the NA61/SHINE and NA49 experiments in inelastic proton–proton (<inline-formula><math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>p</mi><mi>p</mi></mrow></semantics></math></inline-formula>) and central Lead–Lead (<inline-formula><math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>P</mi><mi>b</mi><mo>−</mo><mi>P</mi><mi>b</mi></mrow></semantics></math></inline-formula>), Argon–Scandium (<inline-formula><math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>A</mi><mi>r</mi><mo>−</mo><mi>S</mi><mi>c</mi></mrow></semantics></math></inline-formula>), and Beryllium–Beryllium (<inline-formula><math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>B</mi><mi>e</mi><mo>−</mo><mi>B</mi><mi>e</mi></mrow></semantics></math></inline-formula>) collisions with the Blast-wave model with Boltzmann–Gibbs (BWBG) statistics. The BGBW model was in good agreement with the experimental data. We were able to extract the transverse flow velocity (<inline-formula><math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><msub><mi>β</mi><mi>T</mi></msub></semantics></math></inline-formula>), the kinetic freeze-out temperature (<inline-formula><math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><msub><mi>T</mi><mn>0</mn></msub></semantics></math></inline-formula>), and the kinetic freeze-out volume (<i>V</i>) from the <inline-formula><math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><msub><mi>p</mi><mi>T</mi></msub></semantics></math></inline-formula> spectra using the BGBW model. Furthermore, we also obtained the initial temperature (<inline-formula><math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><msub><mi>T</mi><mi>i</mi></msub></semantics></math></inline-formula>) and the mean transverse momentum (<<inline-formula><math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><msub><mi>p</mi><mi>T</mi></msub></semantics></math></inline-formula>>) by the alternative method. We observed that <inline-formula><math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><msub><mi>T</mi><mn>0</mn></msub></semantics></math></inline-formula> increases with increasing collision energy and collision cross-section, representing the colliding system’s size. The transverse flow velocity was observed to remain invariant with increasing collision energy, while it showed a random change with different collision cross-sections. In the same way, the kinetic freeze-out volume and mean transverse momentum increased with an increase in collision energy or collision cross-section. The same behavior was also seen in the freeze-out temperature, which increased with increasing collision cross-sections. At chemical freeze-out, we also determined both the chemical potential and temperature and compared these with the hadron resonance gas model (HRG) and different experimental data. We report that there is an excellent agreement with the HRG model and various experiments, which reveals the ability of the fit function to manifest features of the chemical freeze-out.
To introduce 3D printing technology into the field of radiation source preparation and make up for the lack of precision special-shaped radiation source preparation technology at home and abroad. The photosensitive resin for 133Cs 3D printing was prepared by studying the phase transfer method and detected by ICP-MS to explore the preparation conditions. Then, the photosensitive resin material for 137Cs 3D printing was prepared and detected by lanthanum bromide detector. The results show that the uneven distribution of cesium in three photosensitive resins for 133Cs 3D printing and 137Cs 3D printing prepared by phase transfer method was less than 5%. As a simple and mild method, phase transfer method can be used to prepare photosensitive resin for 3D printing containing cesium, and has certain universality.
Nuclear and particle physics. Atomic energy. Radioactivity
Abstract We consider a situation where right-handed neutrinos couple to a light scalar which is possibly a Nambu-Goldstone boson resulting from high-energy symmetry breaking. Its coupling is typically complex-valued and flavor-dependent. In this work, we investigate the possibility of the leptonic asymmetry generation in the Universe from the right-handed neutrino decay to flavorful light scalar. Furthermore a new source of asymmetry generation from a single decay process is pointed out, which is characteristic of the present setting.
Nuclear and particle physics. Atomic energy. Radioactivity
This contribution discusses a new perception of the structure of compound nuclei by introducing intermediate states of the Feshbach formalism of nuclear reactions in the Interacting Boson Model of nuclear structure. The stake is to explore the manifestation of the unitary limit in heavy, even-even nuclei. Interactions that govern Feshbach resonances of cold and dilute atomic gases suggest the formulation of an IBM-compound Hamiltonian for scattering two neutrons (2n) from a heavy, even-even target (A). The solutions of the corresponding coupled channel equations host a 2n-IBM state resonance. It turns out that the unitary limit is measurable in a heavy A+2n compound nucleus at low temperatures. That measurement is feasible through the fluctuations of the cross-sections that tune the 2n-A scattering length.
The high energy cosmic rays entering the Earth’s atmosphere throw light upon many aspects of Astroparticle and Particle Physics. This work outlines investigative learning about these high energy primaries based on a mini array DEASA in Agra,India. DEASA (Dayalbagh Educational Air Shower Array) consists of eight plastic scintillators each with an area of 1 square meter. This array covers an area of 260 square meters and is the first array in the northern part of our country. A real-life application of these highly energetic particles has been to find the best material to protect the astronaut from them in form of galactic cosmic rays (GCR). Geant4 based hadronic binary model was used in simulation of phantom, vehicle, SEP (Solar Energetic Particles) and GCR shield. The SEP shielding material was fixed as water and GCR shield was varied among aluminum, Polystyrene and Polyethylene. The poly materials were found to be the best due to large amount of hydrogen (H) and low atomic number (Z). In this work the equivalent dose deposited in the phantom with Polystyrene material for GCR shield was calculated to be minimum (107 sievert) as compared to the other materials.In the second application, the high energy muons have been studied to image nuclear caskets through muon tomography.In this Monte Carlo based simulation, a dry cask container containing different number of the UO2 rods have been bombarded with definite energy muons to measure the muon scattering .The parameters computed in this work are energy loss,radiation length and scattering angle which can calibrate these containers for correct identification of nuclear wastage.
Physics of structured waves is currently limited to relatively small particle energies as the available generation techniques are only applicable to the soft X-ray twisted photons, to the beams of electron microscopes, to cold neutrons, or non-relativistic atoms. The highly energetic vortex particles with an orbital angular momentum would come in handy for a number of experiments in atomic physics, nuclear, hadronic, and accelerator physics, and to generate them one needs to develop alternative methods, applicable for ultrarelativistic energies and for composite particles. Here, we show that the vortex states of in principle arbitrary particles can be generated during photon emission in helical undulators, via Cherenkov radiation, in collisions of charged particles with intense laser beams, in such scattering or annihilation processes as $$e\mu \rightarrow e\mu , ep \rightarrow ep, e^-e^+ \rightarrow p\bar{p}$$ e μ → e μ , e p → e p , e - e + → p p ¯ , and so forth. The key element in obtaining them is the postselection protocol due to entanglement between a pair of final particles and it is largely not the process itself. The state of a final particle – be it a $$\gamma $$ γ -ray, a hadron, a nucleus, or an ion – becomes twisted if the azimuthal angle of the other particle momentum is measured with a large error or is not measured at all. As a result, requirements to the beam transverse coherence can be greatly relaxed, which enables the generation of highly energetic vortex beams at accelerators and synchrotron radiation facilities, thus making them a new tool for hadronic and spin studies.
Background: Atomic physics and nuclear matter physics are often exclusively studied. However, atomic properties are a direct function of nuclear properties. Establishing a mathematical relationship between nuclear and atomic properties could serve the interest of nuclear and atomic engineers. Nuclear - and atomic-based instrumentation engineering and nuclear medicine (and perhaps atomic medicine) applications could be the benefits. Objectives: The research is undertaken to 1) link nuclear property, the mass-radius of the nucleon, and ionization energy of hydrogen via the derivation of appropriate equation and 2) determine the mass-radii of the nucleons and some leptons. Methods: Theoretical and computational methods. Results and Discussion: As applicable to the previous results in the literature, the larger the mass of the elementary particles, the longer the radii. For the particles investigated, the order of the radius is muon (m-)<proton (p+)< neutron (n)< tauon (t-) corresponding to increasing mass, m-<p+< n<t-. The values of the mass radii were respectively » 0.1240, 1.1012, 1.1027, and 2.0855 fm. Conclusion: Nuclear properties such as the radius of any nucleon (ΓN) can be mathematically linked to atomic properties such as the ionization energy of hydrogen via equation which shows that ΓN is inversely proportional to the ionization energy of hydrogen and directly proportional to the rest-mass of the particle.
Abstract We compute the leading order non-Gaussianity, i.e., the bispectrum, of the tensor perturbation in the general α-vacuum on de Sitter space in general relativity. In addition to the well-known Bunch-Davies (BD) vacuum, there exits an infinite number of de Sitter invariant vacua represented by a real parameter α and a phase ϕ, with α = 0 being the BD vacuum. They are called α-vacua. In the standard slow-roll inflation, as de Sitter invariance no longer applies, the α-vacua lose its relevance in the rigorous sense. Nevertheless, if we assume that the parameter α is only weakly dependent on the wavenumber with an appropriate UV cutoff, we may consider pseudo-α-vacua. In the case of false vacuum inflation where the background spacetime is pure de Sitter, a non-trivial (non-BD) α-vacuum could indeed be realized. We find an intriguing result that the bispectrum may be exponentially enhanced to be detectable by observation even if the spectrum is too small to be detected.
Nuclear and particle physics. Atomic energy. Radioactivity