HEP Phenomenology·hep-ph
34 papers—23 primary·11 cross-listed·reconstructed*
The method proposed by Kinoshita and Nio to compute higher order vacuum polarization contributions to the Coulomb potential in muonic hydrogen is generalized to obtain relativistic corrections to their results.
We compute the baryon asymmetry in the Universe in the framework of the standard model with the only source of CP violation in the CKM matrix. Our result is within and very close to the theoretical limits for baryon asymmetry found in the literature and too small to account for the experimentally required baryon asymmetry in standard cosmologies. The method can be easily extended to beyond standard model theories.
Eric Braaten🇺🇸 · Daekyoung Kang🇨🇳 · Ranjan Laha🇩🇪
The small-scale structure problems of the universe can be solved by self-interacting dark matter that becomes strongly interacting at low energy. A particularly predictive model for the self-interactions is resonant short-range interactions with an S-wave scattering length that is much larger than the range. The velocity dependence of the cross section in such a model provides an excellent fit to self-interaction cross sections inferred from dark-matter halos of galaxies and clusters of galaxies if the dark-matter mass is about 19 GeV and the scattering length is about 17 fm. Such a model makes definite predictions for the few-body physics of weakly bound clusters of the dark-matter particles. The formation of the two-body bound cluster is a bottleneck for the formation of larger bound clusters. We calculate the production of two-body bound clusters by three-body recombination in the early universe under the assumption that the dark matter particles are identical bosons, which is the most favorable case. If the dark-matter mass is 19 GeV and the scattering length is 17 fm, the fraction of dark matter in the form of two-body bound clusters can increase by as much as 4 orders of magnitude when the dark-matter temperature falls below the binding energy, but its present value remains less than 10^(-6). The present fraction can be increased to as large as 10^(-3) by relaxing the constraints from small-scale structure and decreasing the mass of the dark matter particle.
Fredrik Björkeroth🇮🇹 · Eung Jin Chun🇰🇷 · Stephen F. King🇬🇧
We present a comprehensive discussion of the phenomenology of flavourful axions, including both standard Peccei-Quinn (PQ) axions, associated with the solution to the strong problem, and non-standard axion-like particles (ALPs). We give the flavourful axion-fermion and axion-photon couplings and calculate the branching ratios of heavy meson (, , ) decays involving a flavourful axion. We also calculate the mixing between axions and heavy mesons , , and , which affects the meson oscillation probability and mass difference. Mixing also contributes to meson decays into axions and axion decays into two photons, and may be relevant for ALPs. We discuss charged lepton flavour-violating decays involving final state axions of the form , as well as and conversion. Finally we describe the phenomenology of a particular "A to Z" Pati-Salam model, in which PQ symmetry arises accidentally due to discrete flavour symmetry. Here all axion couplings are fixed by a fit to flavour data, leading to sharp predictions and correlations between flavour-dependent observables.
Xue-Ke Song🇨🇳 · Yanqi Huang🇨🇳 · Jiajie Ling🇨🇳 · Man-Hong Yung🇨🇳
Neutrino oscillation represents an intriguing physical phenomenon where the quantumness can be maintained and detected over a long distance. Previously, the non-classical character of neutrino oscillation was tested with the Leggett-Garg inequality, where a clear violation of the classical bound was observed [J. A. Formaggio et al., Phys. Rev. Lett. 117, 050402 (2016)]. However, there are several limitations in testing neutrino oscillations with the Leggett-Garg inequality. In particular, the degree of violation of the Leggett-Garg inequality cannot be taken as a "measure of quantumness". Here we focus on quantifying the quantumness of experimentally-observed neutrino oscillation, using the tools of recently-developed quantum resource theory. We analyzed ensembles of reactor and accelerator neutrinos at distinct energies from a variety of neutrino sources, including Daya Bay (0.5 km and 1.6 km), Kamland (180 km), MINOS (735 km), and T2K (295 km). The quantumness of the three-flavoured neutrino oscillation is characterized within a 3{\sigma} range relative to the theoretical prediction. It is found that the maximal coherence was observed in the neutrino source from the Kamland reactor. However, even though the survival probability of the Daya Bay experiment did not vary significantly (dropped about 10 percent), the coherence recorded can reach up to 40 percent of the maximal value. These results represent the longest distance over which quantumness were experimentally determined for quantum particles other than photons.
Patrick deNiverville🇰🇷 · Hye-Sung Lee🇰🇷 · Min-Seok Seo🇰🇷
The dark axion portal is a recently introduced portal between the standard model and the dark sector. It connects both the dark photon and the axion (or axion-like particle) to the photon simultaneously through an anomaly triangle. While the vector portal and the axion portal have been popular venues to search for the dark photon and axion, respectively, the new portal provides new detection channels if they coexist. The dark axion portal is not a result of the simple combination of the two portals, and its value is not determined by the other portal values; it should be tested independently. In this paper, we discuss implications of the new portal for the leptonic g-2, B-factories, fixed target neutrino experiments, and beam dumps. We provide the model-independent constraints on the axion-photon-dark photon coupling and discuss the sensitivities of the recently activated Belle-II experiment, which will play an important role in testing the new portal.
Zhou Rui🇨🇳 · Jie Zhang🇨🇳 · Li-li Zhang🇨🇳
Inspired by a series of unexpected measurements of semileptonic decays mediated via charged current interactions, we explore semileptonic decays to the four lightest -wave charmonium states, , by the recently developed improved perturbative QCD formalism, in which the charm quark mass effect is included both in the Sudakov factor and the hard kernels. We first directly evaluate the concerned transition form factors with vector and axial-vector currents in the region of small momentum transfer squared, and then recast them to the full kinematical region by adopting the exponential parametrization. The obtained form factors are used to evaluate the semileptonic decay branching ratios, which can reach the order of , letting the corresponding measurement appear feasible. For a better analysis, a comparison of our results with the predictions of other models is provided. We also present the ratios between the tau and light lepton branching ratios and the polarization contributions in the relevant processes, which still need experimental tests in the ongoing and forthcoming experiments. Any significant deviations from the Standard Model results may provide some hints of new physics effects.
Francesco Luciano🇮🇹 · Enrico Meggiolaro🇮🇹
We perform a systematic study of the modifications to the QCD vacuum energy density in the zero-temperature case () caused by a small, but non-zero, value of the parameter , using different effective Lagrangian models which include the flavour-singlet meson field and implement the axial anomaly of the fundamental theory. In particular, we derive the expressions for the topological susceptibility and for the second cumulant starting from the dependence of in the various models that we have considered. Moreover, we evaluate numerically our results, so as to compare them with each other, with the predictions of the Chiral Effective Lagrangian, and, finally, also with the available lattice data.
Y.K. Hsiao🇨🇳 · C.Q. Geng🇨🇳 · Eduardo Rodrigues🇺🇸
The LHCb collaboration has presented first experimental evidence that spin-carrying matter and antimatter differ. The study looked at four-body decays of the baryon. Differences in the behaviour of matter and antimatter are associated with the non-invariance of fundamental interactions under the combined charge-conjugation and parity transformations, known as violation. We discuss purely baryonic decay processes, i.e. decay processes involving only spin-carrying particles. They are yet unexplored elementary processes. Their study opens a new chapter of flavour physics in the route towards a better understanding of violation. It may help us to understand the observed matter and antimatter asymmetry of the Universe.
Giacomo Cacciapaglia🇫🇷 · Aldo Deandrea🇫🇷 · Naveen Gaur🇮🇳 · Daisuke Harada🇨🇳 · Yasuhiro Okada🇯🇵 · Luca Panizzi🇮🇹
The existence of new vector-like quarks is often predicted by models of new physics beyond the Standard Model, and the development of discovery strategies at colliders is the object of an intense effort from the high-energy community. Our analysis aims at identifying the constraints on and peculiar signatures of simplified scenarios containing \textit{two} vector-like quark doublets mixing with \textit{any} of the SM quark generations. This scenario is a necessary ingredient of a broad class of theoretically motivated constructions. We focus on the two charge states that, due to their peculiar mixing patterns, feature new production and decay modes that are not searched for at the LHC: single production of the heavier state can dominate over the light one, while pair production via electroweak interactions overcomes the QCD one for masses at the TeV scale.
Suchismita Sahoo🇮🇳 · Rukmani Mohanta🇮🇳
Motivated by the recent measurement of the lepton flavour nonuniversality ratio by the LHCb Collaboration, we study the implications of vector leptoquarks on the observed anomalies associated with the decay processes. The leptoquark couplings are constrained from the measured branching ratios of , and processes. Using these constrained couplings, we estimate the branching ratios, forward-backward and lepton polarization asymmetries and also the form factor independent optimized observables () for modes in the high recoil limit. We also study the other lepton flavour universality violating observables, such as , and , where . Furthermore, we investigate the lepton flavour violating decay process in this model.
Qi-Fang Lü🇨🇳 · Li-Ye Xiao🇨🇳 · Zuo-Yun Wang🇨🇳 · Xian-Hui Zhong🇨🇳
Considering the mass, parity and decay mode, we tentatively assign the as the wave states with one radial excitation. Then, via studying the strong decay behavior of the within the model, we obtain that the total decay widths of the and states are 16.27 MeV and 25.39 MeV, respectively. Compared with the experimental total width measured by LHCb Collaboration, both assignments are allowed, and the assignment is more favorable. Other mode states are also investigated, which are most likely to be narrow states and have good potential to be observed in future experiments.
Alex Kovner🇺🇸 · Michael Lublinsky🇮🇱 · Mirko Serino🇮🇱
Working in the framework of the Color Glass Condensate effective theory of high energy QCD, we revisit the momentum space entanglement entropy of the soft gluons produced in high energy dilute-dense collisions. We extend the work of~\cite{Kovner:2015hga} by considering entropy produced in a single event. This entropy arises due to decoherence of eigenstates with different energies during the time evolution after the collisions with the target. We define it rigorously as the entanglement entropy of the produced system with the experimental apparatus. We compute the time dependent single event entropy in the limit of weak projectile field. Further we compute the entropy for the ensemble of events defined by the McLerran-Venugopalan model for the projectile wave function. Interestingly the entropy of the ensemble has a much weaker time dependence than the entropy in any single event. We attribute this feature to the so called monogamy of entanglement.
Basabendu Barman🇮🇳 · Subhaditya Bhattacharya🇮🇳 · Mohammadreza Zakeri🇨🇳
An extension ( stands for neutral) of the Standard Model (SM) is proposed with an additional global symmetry, which stabilizes the lightest of the vector boson () as dark matter (DM) through unbroken . The field content of the model is motivated to address neutrino mass generation, a possible unification to , along with spontaneous symmetry breaking of resulting in massive gauge bosons. None of the SM particles are charged under and therefore do not have a direct coupling to the visible sector besides a Higgs portal, which is tiny to avoid any conflict with Higgs data. We show that, a large kinematic region of this model allows the neutral component of scalar triplet and heavy neutrinos introduced here to become additional DM components. In this paper we explore the viability of such multipartite DM parameter space, including non-zero DM-DM interactions, to comply with relic density and direct search constraints. We also demonstrate that the model may yield hadronically quiet single lepton and two lepton signatures with missing energy at the Large Hadron Collider (LHC) that can be accessed with high luminosity.
Muhammad Naeem Anwar🇨🇳 · Yu Lu🇩🇪 · Bing-Song Zou🇨🇳
Invoked by the recent CMS observation regarding candidates of the multiplet, we analyze the ultrafine and mass splittings among multiplet in our unquenched quark model (UQM) studies. The mass difference of and in multiplet measured by CMS collaboration ( MeV) is very close to our theoretical prediction ( MeV). Our corresponding mass splitting of and enables us to predict more precisely the mass of to be () MeV. Moreover, we predict ratios of the radiative decays of candidates, both in UQM and quark potential model. Our predicted relative branching fraction of is one order of magnitude smaller than , this naturally explains the non-observation of in recent CMS search. We hope these results might provide useful references for forthcoming experimental searches.
Transversity generalized parton distributions (GPDs) appear as scalar functions in the decomposition of off-forward quark-quark and gluon-gluon correlators with a parton helicity flip. For a spin 1 hadron, we find 9 transversity GPDs for both quarks and gluons at leading twist 2. We study these twist-2 chiral odd quark transversity GPDs for the deuteron in a light cone convolution model, based on the impulse approximation, and using the lowest Fock-space state for the deuteron.
Lobsang Dhargyal🇮🇳 · Santosh Kumar Rai🇮🇳
We study the phenomenological constraints and consequences in the flavor sector, of introducing a new fourth generation odd vector-like lepton doublet along with a Standard Model (SM) singlet scalar and an singlet scalar leptoquark carrying electromagnetic charge of , both odd under a . We show that with little fine tuning among the various Yukawa couplings in the new physics (NP) Lagrangian along with the CKM parameters, the model is able to push the theoretical value of from to and from to compared to the SM value. Especially the NP contributions are able to reduce the discrepancy between experiment and theory of substantially compared to SM. This is quite impressive given that the model satisfy all other very stringent constrains coming from neutral meson oscillations and precision -pole data.
To prove the momentum sum rule in the operator product expansion (OPE) in QCD at high energy colliders it is assumed that where is the momentum eigenstate of the hadron with momentum and is the component of the gauge invariant color singlet energy-momentum tensor density operator of all the quarks plus antiquarks plus gluons inside the hadron . However, in this paper, we show that this relation is correct if is the energy-momentum tensor density operator of the hadron but this relation is not correct if is the gauge invariant color singlet energy-momentum tensor density operator of all the quarks plus antiquarks plus gluons inside the hadron. Hence we find that the momentum sum rule is violated in the operator product expansion (OPE) in QCD at high energy colliders.
Suyong Choi🇰🇷 · Seung J. Lee🇰🇷 · Maxim Perelstein🇺🇸
Neural network-based algorithms provide a promising approach to jet classification problems, such as boosted top jet tagging. To date, NN-based top taggers demonstrated excellent performance in Monte Carlo studies. In this paper, we construct a top-jet tagger based on a Convolutional Neural Network (CNN), and apply it to parton-level boosted top samples, with and without an additional gluon in the final state. We show that the jet observable defined by the CNN obeys the canonical definition of infrared safety: it is unaffected by the presence of the extra gluon, as long as it is soft or collinear with one of the quarks. Our results indicate that the CNN tagger is robust with respect to possible mis-modeling of soft and collinear final-state radiation by Monte Carlo generators.
Peter B. Denton🇩🇰 · Stephen J. Parke🇺🇸 · Xining Zhang🇺🇸
We further develop a simple and compact technique for calculating the three flavor neutrino oscillation probabilities in uniform matter density. By performing additional rotations instead of implementing a perturbative expansion we significantly decrease the scale of the perturbing Hamiltonian and therefore improve the accuracy of zeroth order. We explore the relationship between implementing additional rotations and that of performing a perturbative expansion. Based on our analysis, independent of the size of the matter potential, we find that the first order perturbation expansion can be replaced by two additional rotations and a second order perturbative expansion can be replaced by one more rotation. Numerical tests have been applied and all the exceptional features of our analysis have been verified.
Stefan Alte🇩🇪 · Matthias König🇨🇭 · Matthias Neubert🇩🇪
When a new heavy particle is discovered at the LHC or at a future high-energy collider, it will be interesting to study its decays into Standard Model particles using an effective field-theory framework. We point out that the proper effective theory can not be constructed as an expansion in local, higher-dimensional operators; rather, it must be based on non-local operators defined in soft-collinear effective theory (SCET). For the interesting case where the new resonance is a gauge-singlet spin-0 boson, which is the first member of a new sector governed by a mass scale , we show how a consistent scale separation between and the electroweak scale is achieved up to next-to-next-to-leading order in the expansion parameter . The Wilson coefficients in the effective Lagrangian depend in a non-trivial way on the mass of the new resonance and the masses of yet undiscovered heavy particles. Large logarithms of the ratio can be systematically resummed using the renormalization group. We develop a SCET toolbox, with which it is straightforward to construct the relevant effective Lagrangians for new heavy particles with other charges and spin.
We determine the most general non-relativistic theory of DM-nucleon scattering complying with the sole requirement of Lorentz invariance, for spin-0 and spin-1/2 DM. To do so, we first classify a comprehensive list of amplitude terms encompassing the most general Lorentz-covariant 2-to-2 DM-nucleon scattering amplitude. We then match each term to a Galilean-invariant operator at leading-order in the non-relativistic expansion, for both elastic and inelastic (endothermic and exothermic) scattering. Our complete Lorentz-to-Galileo mapping can be used to promptly determine the non-relativistic DM-nucleon interaction and the associated nuclear form factor for any given Lorentz-invariant DM model. It applies to both renormalizable and non-renormalizable theories (such as effective field theories at all orders), at any order of a perturbative expansion. We use our results to prove that, at leading order, Lorentz invariance does not impose restrictions on the set of 16 Galilean-invariant operators commonly used to parametrize the non-relativistic DM-nucleon interaction. We also predict the lowest effective-operator dimension at which the non-relativistic operators appear in the effective field theory of a singlet DM particle.
Ye Xing🇨🇳 · Ruilin Zhu🇨🇳
In the light of the recent discovery of the by LHCb collaboration, we study the stable doubly heavy tetraquarks. These states are compact exotic hadrons which can be approximated as the diquark-anti-diquark correlations. In the flavor SU(3) symmetry, they form an SU(3) triplet or anti-sextet. The spectra of the stable doubly heavy tetraquark states are predicted by Sakharov-Zeldovich formula. We find that the is about 16MeV below the threshold, while is about 73MeV below the threshold. We then study the semileptonic and nonleptonic weak decays of the stable doubly heavy tetraquark states. The decay amplitudes are parametrized in terms of SU(3)-irreducible amplitudes. Ratios between decay widths of different channels are also derived. At the end, we collect the Cabibbo allowed two-body and three-body decay channels, which are most promising to search for the stable doubly heavy tetraquark states at LHCb and Belle II experiments.
C. Furey🇬🇧
We demonstrate a model which captures certain attractive features of theory, while providing a possible escape from proton decay. In this paper we show how ladder operators arise from the division algebras , , , and . From the symmetry of these ladder operators, we then demonstrate a model which has much structural similarity to Georgi and Glashow's grand unified theory. However, in this case, the transitions leading to proton decay are expected to be blocked, given that they coincide with presumably forbidden transformations which would incorrectly mix distinct algebraic actions. As a result, we find that we are left with . Finally, we point out that if ladder symmetries are used in place of , it may then be possible to find this same , together with an extra symmetry, related to .
In this paper we consider the simplest functional Schroedinger equation of a quantum field theory (in particular QCD) and study its solutions. We observe that the solutions to this equation must possess a number of properties. Its Taylor coefficients are multivalued functions with rational and logarithmic branchings and essential singularities of exponential type. These singularities occur along a locus defined by polynomial equations. The conditions we find define a class of functions that generalizes to multiple dimensions meromorphic functions with finite Nevanlinna type. We note that in perturbation theory these functions have local asymptotics that is given by multidimensional confluent hypergeometric functions in the sense of Gelfand-Kapranov-Zelevinsky.
Shang Li🇨🇳 · Zi-Qing Xia🇨🇳 · Yun-Feng Liang🇨🇳 · Kai-Kai Duan🇨🇳 · Zhao-Qiang Shen🇨🇳 · Xiang Li🇨🇳 · Lei Feng🇨🇳 · Qiang Yuan🇨🇳 · Yi-Zhong Fan🇨🇳 · Jin Chang🇨🇳
In order to search for the line-like signals in the Fermi-LAT data, we have analyzed totally 49152 regions of interest (ROIs) that cover the whole sky. No ROI displays a line signal with test statistic (TS) value above 25, while for 50 ROIs weak line-like excesses with are presented. The intrinsic significances of these potential signals are further reduced by the large trial factor introduced in such kind of analysis. For the largest TS value of 24.3 derived in our analysis, the corresponding global significance is only . We thus do not find any significant line-like signal and set up constraints on the cross section of dark matter annihilating to gamma-ray lines, .
Emanuela Dimastrogiovanni🇺🇸 · Matteo Fasiello🇬🇧 · Gianmassimo Tasinato🇬🇧
We study how inflationary observables associated with primordial tensor modes are affected by coupling the minimal field content with an extra spin-2 particle during inflation. We work with a model that is ghost-free at the fully non-linear level and show how the new degrees of freedom modify standard consistency relations for the tensor bispectrum. The extra interacting spin-2 field is necessarily massive and unitarity dictates its mass be in the range. Despite the fact that this bound selects a decaying solution for the corresponding tensor mode, cosmological correlators still carry the imprints of such "fossil" fields. Remarkably, fossil(s) of spin generate distinctive anisotropies in observables such as the tensor power spectrum. We show how this plays out in our set-up.
Kenji Aoki🇯🇵 · Daisuke Jido🇯🇵
We revisit the scattering amplitude in order to investigate the possibility for the existence of a broad resonance in the channel around the energy of 1617 MeV with 305 MeV width. We use the chiral unitary model to describe the scattering amplitudes and determine the model parameters so as to reproduce the differential cross sections of the scatterings and the and 1 total cross sections up to MeV/c, from which inelastic contributions start to be significant. Performing analytic continuation of the determined amplitude to the complex energy plane, we find a pole for a broad resonance state. We point out that the rapid increase appearing in the total cross section around MeV/c is a hint of the possible broad resonance of strangeness .
In this paper we will show some applications achieved within type IIB superstring backgrounds since the emergence of the AdS/CFT correspondence. This correspondence relates a super Yang-Mills (SYM) theory, with strong coupling, and a type IIB superstring theory, with weak coupling. The use of the AdS/CFT correspondence allows us to investigate many aspects of hadronic physics described by QCD outside the perturbative regime, for example, glueball masses and the Regge trajectories related to the pomeron and the odderon. Throughout the text we will deal with the AdS/CFT correspondence within the two dynamical versions to the holographic softwall model.
We study multivariate Mellin transforms of Laurent polynomials by considering special toric compactifications which make their singular structure apparent. This gives a precise description of their convergence domain, refining results of Nilsson, Passare, Berkesch and Forsgård. We also reformulate the geometric sector decomposition approach of Kaneko and Ueda in terms of these compactifications. Specializing to the case of Feynman integrals in the parametric representation, we construct multiple such compactifications given by certain systems of subgraphs. As particular cases, we recover the sector decompositions of Hepp, Speer and Smirnov, as well as the iterated blow-up constructions of Brown and Bloch-Esnault-Kreimer. A fundamental role is played by the Newton polytope of the product of the Symanzik polynomials, which we show to be a generalized permutahedron for generic kinematics. As an application, we review two approaches to dimensional regularization of Feynman integrals, based on sector decomposition and on analytic continuation.
P. Thomas Jahn🇩🇪 · Guy D. Moore🇩🇪 · Daniel Robaina🇩🇪
We calculate the topological susceptibility at 2.5 Tc and 4.1 Tc in SU(3) pure Yang-Mills theory. We define topology with the help of gradient flow and we largely overcome the problem of poor statistics at high temperatures by applying a reweighting technique in terms of the topological charge, measured after a specific small amount of gradient flow. This allows us to obtain a sample of configurations which compares topological sectors with good statistics, with enhanced tunneling between topologies. We quote continuum extrapolated results at these two temperatures and conclude that our method is viable and can be extended without new conceptual problems to the case of full QCD with fermions.
H1 Collaboration · H. Spiesberger
The parameters of the electroweak theory are determined in a combined electroweak and QCD analysis using all deep-inelastic and neutral current and charged current scattering cross sections published by the H1 Collaboration, including data with longitudinally polarised lepton beams. Various fits to Standard Model parameters in the on-shell scheme are performed. The mass of the boson is determined as GeV. The axial-vector and vector couplings of the light quarks to the boson are also determined. Both results improve the precision of previous H1 determinations based on HERA-I data by about a factor of two. Possible scale dependence of the weak coupling parameters in both neutral and charged current interactions beyond the Standard Model is also studied. All results are found to be consistent with the Standard Model expectations.
Tomoyuki Maruyama · Takehito Hayakawa. Toshitaka Kajino
We calculate the differential cross sections for Compton scattering of photons described by Hermite Gaussian (HG) wave function in the framework of relativistic quantum mechanics. The HG wave gamma-rays propagating along the z-direction have quantum numbers of nodes of nx and ny in the x- and y-directions, respectively. The calculated differential cross section is symmetric with respect to both the zx- and zy-planes. The nodes whose number is identical with nx and ny appear in the energy spectrum measured in zx- and zy-planes, respectively. These results indicate that it is possible to identify the HG wave photon and its quantum numbers nx and ny by measuring Compton scattering. The present proposed method can be also applied to gamma-ray astronomy.
Qing-Wu Wang🇨🇳 · Si-Xue Qin🇨🇳 · Craig D. Roberts🇺🇸 · Sebastian M. Schmidt🇩🇪
The proton's tensor charges are calculated at leading order in a symmetry-preserving truncation of all matter-sector equations relevant to the associated bound-state and scattering problems. In particular, the nucleon three-body bound-state equation is solved without using a diquark approximation of the two-body scattering kernel. The computed charges are similar to those obtained in contemporary simulations of lattice-regularised quantum chromodynamics, an outcome which increases the tension between theory and phenomenology. Curiously, the theoretical calculations produce a value of the scale-invariant ratio which matches that obtained in simple quark models, even though the individual charges are themselves different. The proton's tensor charges can be used to constrain extensions of the Standard Model using empirical limits on nucleon electric dipole moments.
* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.