Abstract A line of first-order phase transitions is conjectured in the phase diagram of Quantum Chromodynamics at non-zero baryon density. If this is the case, numerical simulations of neutron star mergers suggest that various regions of the stars may cross this line multiple times. This results in the nucleation of bubbles of the preferred phase, which subsequently expand and collide. The resulting gravitational wave spectrum is highly sensitive to the velocity of the bubble walls. We use holography to perform the first microscopic simulation of bubble dynamics in a theory that qualitatively mirrors the expected phase diagram of Quantum Chromodynamics. We determine the wall velocity in the metastable regions and we compare it to theoretical estimates. We discuss implications for gravitational wave production.
Nuclear and particle physics. Atomic energy. Radioactivity
Abstract We investigate the phase diagram of the three-dimensional SU(3) spin model with finite chemical potential, which is an effective Polyakov loop model for finite density QCD, using the tensor renormalization group method. We successfully determine the location of the critical endpoints being free from the complex action problem in the standard Monte Carlo approach. The critical values of the parameters show the consistency with previous ones obtained by other analytic and numerical methods.
Nuclear and particle physics. Atomic energy. Radioactivity
Abstract We propose a systematic method to block-diagonalize the finite volume effective Hamiltonian for two-particle systems with arbitrary spin in both the rest and moving frame. The framework is convenient and efficient for addressing the left-hand cut issue arising from long-range potential, which are challenging in the framework of standard Lüscher formula. Furthermore, the method provides a foundation for further extension to three-particle systems. We first benchmark our method by examining several toy models, demonstrating its consistency with standard Lüscher formula in the absence of long-range potential. In the presence of long-range potential, we investigate and resolve the effects and issues of left-hand cut. As a realistic application, we calculate the finite volume spectra of isoscalar D D ¯ ∗ $$ D{\overline{D}}^{\ast } $$ system, where the well-known exotic state χ c1(3872) is observed. The results are qualitatively consistent with the lattice QCD calculation, highlighting the reliability and potential application of our framework to the study of other exotic states in hadron physics.
Nuclear and particle physics. Atomic energy. Radioactivity
E. N. Shleenkova, S. Yu. Bazhin, V. Yu. Bogatyreva
With the active development and wide use of positron emission tomography, ensuring radiation safety in matters of irradiation of the skin of the hands of personnel, has become very important. Work with radiopharmaceuticals labeled with various radionuclides is characterized by fairly close contact with a source of ionizing radiation, during which the skin of the hands can be irradiated in significant doses. Thus, the effect of ionizing radiation on the skin of the hands is one of the main problems of radiation protection of personnel at nuclear medicine centers. The work of personnel at nuclear medicine centers, depending on the nature of the actions performed, can be divided into two types: predominantly manual processes (nurses – packaging and administration of drugs, analytical chemists – quality control) and predominantly automated processes (radiochemical engineers – synthesis, packaging into vials). The individual equivalent doses to the skin of the hands of nurses, analytical chemists and radiochemical engineers working with 18F-based radiopharmaceuticals were estimated using thermoluminescence dosimetry with individual dosimeters calibrated in terms of Hp(0.07). The maximum annual value obtained fo radiochemical engineers was 7.8 mSv, which is 1.56% of the dose limit, and for analytical chemists it was 171 mSv, which is 34% of the dose limit (mean value was 28 mSv, median was 8.8 mSv, minimum value was 4.6 mSv). At the same time, nurses, who are mainly engaged in the packaging and administration of radiopharmaceuticals, have higher values of annual doses in the skin of the hands (mean value – 114 mSv, median – 56 mSv, minimum value – 1.3 mSv). The maximum value of the annual dose in the skin of the hands, recorded during the work, for a nurse was 573 mSv, i.e. the dose limit of 500 mSv was exceeded. The results of the work indicate that specialists involved in manual processes when manipulating radiopharmaceuticals require special attention from the standpoint of individual dosimetric control of the irradiation dose to the skin of the hands and compliance with radiation safety requirements.
Medical physics. Medical radiology. Nuclear medicine, Radioactivity and radioactive substances
Abstract We compute trace relations governing chiral ring elements of fully Ω-deformed N $$ \mathcal{N} $$ = 2⋆ gauge theories with SU(N) gauge groups by demanding the regularity of the fundamental qq-character.
Nuclear and particle physics. Atomic energy. Radioactivity
By compressing matter to densities up to several times the density of atomic nuclei, the catastrophic gravitational collapse of the core of stars with a mass <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>M</mi><mo>≳</mo><mn>8</mn><msub><mi>M</mi><mo>⊙</mo></msub></mrow></semantics></math></inline-formula> during supernova explosions and the neutron star left behind (see, e [...]
Abstract We investigate the exclusive $$J/\psi $$ J / ψ production at the future Electron-ion collider in China by utilizing the eSTARlight event generator. We model the cross-section and kinematics by fitting to the world data of $$J/\psi $$ J / ψ photoproduction. Projected statistical uncertainties on $$J/\psi $$ J / ψ production are based on the design of a central detector, which consists of a tracker and vertex subsystem. The precision of the pseudo-data allows us to probe the near-threshold mechanism, e.g. the re-scattering effect. The significance of the forward amplitudes is discussed as well. The design and optimization of the detector enhance the potential for exploring the near-threshold region and the realm of high four-momentum transfer squared, which is of particular interest on several physics topics.
Astrophysics, Nuclear and particle physics. Atomic energy. Radioactivity
Abstract We compute the pseudo entropy in two-dimensional holographic and free Dirac fermion CFTs for excited states under joining local quenches. Our analysis reveals two of its characteristic properties that are missing in the conventional entanglement entropy. One is that, under time evolution, the pseudo entropy exhibits a dip behavior as the excitations propagate from the joined point to the boundaries of the subsystem. The other is that the excess of pseudo entropy over entanglement entropy can be positive in holographic CFTs, whereas it is always non-positive in free Dirac fermion CFTs. We argue that the entropy excess can serve as a measure of multi-partite entanglement. Its positivity implies that the vacuum state in holographic CFTs possesses multi-partite entanglement, in contrast to free Dirac fermion CFTs.
Nuclear and particle physics. Atomic energy. Radioactivity
Abstract We apply the OPE inversion formula on thermal two-point functions of fermions to obtain thermal one-point function of fermion bi-linears appearing in the corresponding OPE. We primarily focus on the OPE channel which contains the stress tensor of the theory. We apply our formalism to the mean field theory of fermions and verify that the inversion formula reproduces the spectrum as well as their corresponding thermal one-point functions. We then examine the large N critical Gross-Neveu model in d = 2k + 1 dimensions with k even and at finite temperature. We show that stress tensor evaluated from the inversion formula agrees with that evaluated from the partition function at the critical point. We demonstrate the expectation values of 3 different classes of higher spin currents are all related to each other by numerical constants, spin and the thermal mass. We evaluate the ratio of the thermal expectation values of higher spin currents at the critical point to the Gaussian fixed point or the Stefan-Boltzmann result, both for the large N critical O(N) model and the Gross-Neveu model in odd dimensions. This ratio is always less than one and it approaches unity on increasing the spin with the dimension d held fixed. The ratio however approaches zero when the dimension d is increased with the spin held fixed.
Nuclear and particle physics. Atomic energy. Radioactivity
In the framework of the Einstein–Dirac-aether theory we consider a phenomenological model of the spontaneous growth of the fermion number, which is triggered by the dynamic aether. The trigger version of spinorization of the early Universe is associated with two mechanisms: the first one is the aetheric regulation of behavior of the spinor field; the second mechanism can be related to a self-similarity of internal interactions in the spinor field. The dynamic aether is designed to switch on and switch off the self-similar mechanism of the spinor field evolution; from the mathematical point of view, the key of such a guidance is made of the scalar of expansion of the aether flow, proportional to the Hubble function in the isotropic cosmological model. Two phenomenological parameters of the presented model are shown to be considered as factors predetermining the total number of fermions born in the early Universe.
We are delighted to introduce to the readership of Annalen der Physik this special issue, which comes in the wake of a workshop with the same title that was held virtually at the Mainz Institute for Theoretical Physics in November–December 2020. The Gamma Factory initiative, being developed within the Physics Beyond Colliders framework, proposes to create novel research tools at CERN by producing, accelerating, and storing highly relativistic, partially stripped ion beams in the Super Proton Synchrotron and the Large Hadron Collider (LHC) storage rings. By exciting the electronic degrees of freedom of the stored ions with lasers (i.e., primary photon beams), high energy narrow-band, fully polarized (secondary) photon beams will be produced. Their intensities, up to 1017 photons per second, will be several orders of magnitude higher than those of the presently operating light sources in the particularly interesting gammaray energy domain reaching up to 400 MeV, inaccessible with sources based on free-electron lasers. Multiple unprecedented opportunities in atomic, nuclear, particle, and applied physics may be afforded by utilizing the primary beams for spectroscopy of partially stripped ions circulating in the storage ring, as well as by the application of the secondary high-energy photon beams. The Gamma Factory provides a unique scenario of extending the use of the existing CERN accelerator infrastructure, going beyond its design goals, and allowing to open new crossdisciplinary research domains. It may enable groundbreaking
The quantum tunneling and emission of a single constituent nucleon provide a beautifully simple and unique window into the complex properties of atomic nuclei at the extreme edge of nuclear existence. In particular, for odd-odd proton emitting nuclides, the associated decay energy and partial half-life can be used to probe the correlations between the valence neutrons and protons which have been theoretically predicted to favour a new type of nuclear superfluidity, isoscalar neutron-proton pairing, for which the experimental “smoking gun" remains elusive. In the present work, proton emission from the lanthanum isotope $${}_{\,57}^{116}$$ 57 116 La 59 , 23 neutrons away from the only stable isotope $${}_{\,57}^{139}$$ 57 139 La 82 , is reported. 116 La nuclei were synthesised in the fusion-evaporation reaction 58 Ni( 64 Zn, p 5 n ) 116 La and identified via their proton radioactivity using the mass spectrometer MARA (Mass Analysing Recoil Apparatus) and the silicon detectors placed at its focal plane. Comparisons of the measured proton energy ( E p = 718 ± 9 keV) and half-life ( T 1/2 = 50 ± 22 ms) with values calculated using the Universal Decay Law approach indicate that the proton is emitted with an orbital angular momentum l = 2 and that its emission probability is enhanced relative to its closest, less exotic, odd-even lanthanum isotope ( $${}_{\,57}^{117}$$ 57 117 La 60 ) while the proton-emission Q -value is lower. We propose this to be a possible signature for the presence of strong neutron-proton pair correlations in this exotic, neutron deficient system. The observations of γ decays from isomeric states in 116 La and 117 La are also reported. Neutron-proton pairing is a topic of continuous interest in nuclear physics and open questions remain. The authors experimentally observe direct proton decay from the ground state of odd-odd 116La, providing support for the presence of strong neutron-proton pair correlations in this exotic, neutron deficient system.
Abstract We propose a real time holographic framework to study thermalization processes of a family of QFT excited states. The construction builds on Skenderis-van Rees’s holographic duals to QFT Schwinger-Keldysh complex-time ordered paths. Thermalization is explored choosing a set of observables F n which essentially isolate the excited state contribution. Focusing on theories defined on compact manifolds and with excited states defined in terms of Euclidean path integrals, we identify boundary conditions that allow to avoid any number of modes in the initial field state. In the large conformal dimensions regime, we give precise prescriptions on how to compute the observables in terms of bulk geodesics.
Nuclear and particle physics. Atomic energy. Radioactivity
Haag duality is a remarkable property in QFT stating that the commutant of the algebra of observables localized in some region of spacetime is exactly the algebra associated to the causally disconnected region. It is a strong condition on the local structure and has direct consequences on entanglement measures. It was first shown to hold for a free scalar field and causal diamonds by Araki in 1964 and later by many authors in different ways. In particular, Eckmann and Osterwalder (EO) used Tomita-Takesaki modular theory to give a direct proof. However, it is not straightforward to relate this proof to the works of Araki, since they rely on two forms of the canonical commutation relations (CCR), called Segal and Weyl formulations, while EO work as starting point assumes that duality holds in the so-called “first quantization” in the Weyl formulation. It is our purpose to first introduce the works of Araki in a more easy-to-read but still rigorous and self-contained fashion, and show how Haag duality is stated in the Segal and Weyl formulations and in both first and second quantizations (and their immediate combination). This permits to understand the setting of the EO proof of Haag duality. There is nothing essentially new in this manuscript, with the exception of what we consider a simplification of EO proof that uses the adjoint S⁎ of the Tomita operator S instead of introducing several auxiliary operators. We hope this note will be useful for those seeking to understand where Haag duality comes from in a free scalar QFT.
Nuclear and particle physics. Atomic energy. Radioactivity
Abstract We study the consistency of Scalar Gauss-Bonnet Gravity, a generalization of General Relativity where black holes can develop non-trivial hair by the action of a coupling F(Φ) G $$ \mathcal{G} $$ between a function of a scalar field and the Gauss-Bonnet invariant of the space-time. When properly normalized, interactions induced by this term are weighted by a cut-off, and take the form of an Effective Field Theory expansion. By invoking the existence of a Lorentz invariant, causal, local, and unitary UV completion of the theory, we derive positivity bounds for n-to-n scattering amplitudes including exchange of dynamical gravitons. These constrain the value of all even derivatives of the function F(Φ), and are highly restrictive. They require some of the scales of the theory to be of Planckian order, and rule out most of the models used in the literature for black hole scalarization.
Nuclear and particle physics. Atomic energy. Radioactivity
Abstract We construct an ambitwistor string that describes Type II supergravity on AdS3 ×S3 with pure NS flux. The background Einstein equations ensure that the model is anomaly free. The spectrum consists of supergravity fluctuations around this background, with no higher string states. This theory transforms the problem of computing n-point tree-level amplitudes on AdS3 into that of understanding an sl 2 $$ {\mathfrak{sl}}_2 $$ Gaudin integrable system, whose representations are determined by the dual boundary operators and whose spectral parameters correspond to the worldsheet insertion points. The scattering equations take a similar form to flat space, with n(n − 3)/2 parameters τ ij parametrizing the eigenvalues of the Gaudin model.
Nuclear and particle physics. Atomic energy. Radioactivity
S.X. Nakamura, 2, ∗ A. Hosaka, 4 and Y. Yamaguchi University of Science and Technology of China, Hefei 230026, People’s Republic of China State Key Laboratory of Particle Detection and Electronics (IHEP-USTC), Hefei 230036, People’s Republic of China Research Center for Nuclear Physics, Osaka University, Ibaraki 567-0047, Japan Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai 319-1195, Japan The recent LHCb data on B s → J/ψpp̄ revealed a new pentaquark-like Pc(4337) + structure, while finding no evidence for Pc(4312) + discovered earlier in Λb → J/ψpK . Though puzzling, the data actually offer an important hint to understand the nature of the pentaquark candidates. We develop a model to analyze the B s → J/ψpp̄ data. We find that a ΣcD̄ one-loop mechanism causes a threshold cusp that fits well the Pc(4337) + peak. Also, the ΣcD̄ and ΛcD̄ ∗ threshold cusps interfere with each other to reproduce an oscillating behavior in the proton helicity angle distribution. These results combined with our earlier analysis on Λb → J/ψpK − indicate that Pc(4312) + and Pc(4337) + are created by different interference patterns between the ΣcD̄ and ΛcD̄ ∗ (anomalous) threshold cusps. The proposed scenario consistently explains why the Pc(4312) + and Pc(4337) + peaks appear in Λb → J/ψpK − and B s → J/ψpp̄, respectively, but not vice versa or both.
The year 2020 marked the 75th anniversary of the Trinity experiment, the world’s first nuclear explosion, on July 16, 1945, near Alamogordo, New Mexico. Trinity was a vital proof step toward the culmination of the Manhattan Project and the end of World War II. The technical accomplishments made by scientists and engineers from the United States, United Kingdom, and Canada (some originating in Germany, Hungary, Italy, France, and other countries) were recognized by many events in 2020, including a visit to New Mexico’s Los Alamos National Laboratory by U.S. Department of Energy (DOE) National Nuclear Security Administration (NNSA) dignitaries; historical documentaries; and the publication of an excellent book, Trinity, by Oxford physicist Frank Close. The importance of Trinity as a foundational accomplishment for the broad nuclear science and engineering community is clear; indeed, New Mexico’s chapter of the American Nuclear Society (ANS) is referred to as the Trinity Section. The events surrounding Trinity have even entered into high culture with recent performances of John Adams’s opera Doctor Atomic in San Francisco, Amsterdam, Chicago, New York, and Santa Fe. At a high-powered meeting in May 1945, with Vannevar Bush, Gen. George Marshall, Gen. Leslie Groves, Arthur Compton, James Conant, Robert Oppenheimer, Enrico Fermi, and Ernest Lawrence in attendance, Secretary of War Henry L. Stimson spoke the prescient (if somewhat grandiose) words: “This project [the Manhattan Project] should not be considered simply in terms of military weapons, but as a new relationship of man to the universe. This discovery might be compared to the discoveries of the Copernican theory and of the laws of gravity, but far more important than these in its effect on the lives of men. While the advances in the field to date had been fostered by the needs of war, it was important to realize that the implications of the project went far beyond the needs of the present war. It must be controlled if possible to make it an assurance of future peace rather than menace to civilization.” Our universities’ science and engineering luminaries, along with their best graduate students, came together at various Manhattan Project locations across the country under intense pressure and worked at a frenetic wartime pace to successfully develop a workable atomic bomb. This gathering of scientific and technical excellence was a unique event in our history. Their collective effort led to a remarkable outpouring of scientific creativity in nuclear and material sciences and in hydrodynamics and neutronics computations and led to the creation of what would become today’s DOE national laboratories. The historic effort was facilitated in large part by Oppenheimer’s superb (and, at the time, unproven) leadership. The Manhattan Project, together with the Massachusetts Institute of Technology Radiation Laboratory’s wartime work on radar and E. O. Lawrence’s accelerator research, represents the beginnings of big science, bringing thousands of researchers together to solve problems—a model that has since proved so effective for the scientific community in endeavors such as the field of particle physics, the sequencing of the human genome, and the discovery of gravitational waves. To recognize the Trinity anniversary, this special issue of Nuclear Technology focuses on aspects of the science and engineering breakthroughs made during the Manhattan Project at Los Alamos (then called Project Y), *E-mail: mbchadwick@lanl.gov This material is published by permission of Los Alamos National Laboratory, for the U.S. Department of Energy under Contract No. 89233218CNA000001. The US Government retains for itself, and others acting on its behalf, a paid-up, non-exclusive, and irrevocable worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the Government. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way. a The Interim Committee was chartered on May 4, 1945, by President Truman after he learned of the Manhattan Project following Roosevelt’s death, to advise the government on future directions and controls of nuclear technology. NUCLEAR TECHNOLOGY · VOLUME 207 · iii–viii · SUPPLEMENT 1 · 2021 DOI: https://doi.org/10.1080/00295450.2021.1903301
Christopher Raymond, David Ridout, Jørgen Rasmussen
We investigate a class of reducible yet indecomposable modules over the N=2 superconformal algebras. These so-called staggered modules exhibit a non-diagonalisable action of the Virasoro mode L0. Using recent results on the coset construction of N=2 minimal models, we explicitly construct such modules for central charges c=−1 and c=−6. We also describe spectral-flow orbits and symmetries of the families of staggered modules which arise via the coset.
Nuclear and particle physics. Atomic energy. Radioactivity