Search

Context. The existence of axion quark nuggets is a potential consequence of the axion field, which provides a possible solution to the charge-conjugation parity violation in quantum chromodynamics. In addition to explaining the cosmological discrepancy of matter-antimatter asymmetry and a visible-to-dark-matter ratio of Ωdark/Ωvisible ≃ 5, these composite compact objects are expected to represent a potentially ubiquitous electromagnetic background radiation by interacting with ordinary baryonic matter. We conducted an in-depth analysis of axion quark nugget-baryonic matter interactions in the environment of the intracluster medium in the constrained cosmological Simulation of the LOcal Web (SLOW). Aims. Here, we aim to provide upper limit predictions on electromagnetic counterparts of axion quark nuggets in the environment of galaxy clusters by inferring their thermal and non-thermal emission spectrum originating from axion quark nugget-cluster gas interactions. Methods. We analyzed the emission of axion quark nuggets in a large sample of 161 simulated galaxy clusters using the SLOW simulation. These clusters are divided into a sub-sample of 150 galaxy clusters, ordered in five mass bins ranging from 0.8 to 31.7 × 1014M⊙, along with 11 cross-identified galaxy clusters from observations. We investigated dark matter-baryonic matter interactions in galaxy clusters in their present stage at the redshift of z = 0 by assuming all dark matter consists of axion quark nuggets. The resulting electromagnetic signatures were compared to thermal Bremsstrahlung and non-thermal cosmic ray (CR) synchrotron emission in each galaxy cluster. We further investigated individual frequency bands imitating the observable range of the WMAP, Planck, Euclid, and XRISM telescopes for the most promising cross-identified galaxy clusters hosting detectable signatures of axion quark nugget emission. Results. We observed a positive excess in the low- and high-energy frequency windows, where thermal and non-thermal axion quark nugget emission can significantly contribute to (or even outshine) the emission of the intracluster medium (ICM) in frequencies up to νT ≲ 3842.19 GHz and νT ϵ [3.97, 10.99] × 1010GHz, respectively. Emission signatures of axion quark nuggets are found to be observable if CR synchrotron emission of individual clusters is sufficiently low. The degeneracy in the parameters contributing to an emission excess makes it challenging to offer predictions with respect to pinpointing specific regions of a positive axion quark nugget excess; however, a general increase in the total galaxy cluster emission is expected based on this dark matter model. Axion quark nuggets constitute an increment of 4.80% of the total galaxy cluster emission in the low-energy regime of νT ≲ 3842.19 GHz for a selection of cross-identified galaxy clusters. We propose that the Fornax and Virgo clusters represent the most promising candidates in the search for axion quark nugget emission signatures. Conclusions. The results from our simulations point towards the possibility of detecting an axion quark nugget excess in galaxy clusters in observations if their signatures can be sufficiently disentangled from the ICM radiation. While this model proposes a promising explanation for the composition of dark matter, with the potential to have this outcome verified by observations, we propose further changes that are aimed at refining our methods. Our ultimate goal is to identify the extracted electromagnetic counterparts of axion quark nuggets with even greater precision in the near future. [ABSTRACT FROM AUTHOR]

Ever since new tetrads in four-dimensional Lorentzian curved spacetimes were introduced, many outstanding properties and results have been proven regarding Riemannian geometry, gauge theory or group theory. These tetrads might carry spacetime-kinematic information about particle multiplets. Among other properties, these new tetrads, locally and covariantly diagonalize stress–energy tensors. In the case where particles have an electromagnetic field, the local planes of gauge symmetry served as a tool in order to propose a new gravitational-kinematic interpretation of particle multiplets. The core reason stems from the mathematical fact that all local gauge symmetries associated to the Standard Model have been proven to be isomorphic to local groups of tetrad transformations in four-dimensional Lorentzian spacetimes. Therefore, the different stress–energy tensors have been proven to determine the local gauge geometry as a natural part of Riemannian geometry. The stress–energy tensors determine locally the orthogonal planes such that the rotation on either of them of the local tetrad vectors that span these planes is isomorphic to local tetrad gauge transformations. All these properties put together allow for a reinterpretation presented previously of particle states as particle gravitational-kinematic-spacetime tetrad states in the asymptotically flat limit. We proceed in this paper to study the case where there are T , U and V isospin subalgebras or submultiplets within the context of this new Riemannian interpretation of gauge symmetries. [ABSTRACT FROM AUTHOR]

Properties of doubly charged scalar tetraquarks bb c ¯ c ¯ are investigated in the framework of the Quantum Chromodynamic (QCD) sum rule method. We model them as diquark–antidiquark states X 1 and X 2 built of axial-vector and pseudoscalar diquarks, respectively. The masses and current couplings of these particles are computed using the QCD two-point sum rule method. Results m 1 = (12715 ± 80) MeV and m 2 = (13370 ± 95) MeV obtained for the masses of these particles are used to determine their kinematically allowed decay modes. The full width Γ1 of the state X 1 is evaluated by taking into account its strong decays to mesons 2 B c − , and 2 B c * − . The processes X 2 → 2 B c − , 2 B c * − and B c − B c − (2 S) are employed to estimate Γ2. Predictions obtained for the full widths Γ1 = (63 ± 12) MeV and Γ2 = (79 ± 14) MeV of these structures and their masses may be utilized in experimental studies of fully heavy resonances. [ABSTRACT FROM AUTHOR]

This work presents the application of the q‐algebra in the glueball spectrum. This algebra is implemented through Jackson's derivatives in a Schrödinger‐like equation resulting from the gravity fluctuations around the braneworld scenario in five dimensions. In our prescription, we consider a four‐dimensional AdS4 brane, living in AdS5 bulk, that is also known for describing locally localized gravity via quasizero mode. At the appropriate limit, this background leads to confinement and allows us to find the shape of the q‐deformed glueball spectrum in the AdS5/QCD4 correspondence. The introduction of the q‐deformation provides us with a richer glueball spectrum. [ABSTRACT FROM AUTHOR]

In this paper, we study the contribution of color correlations to Double Parton Scattering (DPS). We show that there is a specific class of Feynman diagrams related to so-called 1 → 2 processes when the contribution of these color correlations is not Sudakov suppressed with the transverse scales. The effective absence of Sudakov suppression gives hope that although they are small relative to color singlet correlations, they eventually can be observed. [ABSTRACT FROM AUTHOR]

We present the first determination of the value of the strong coupling via a simultaneous global fit of the proton parton distribution functions (PDFs) at approximate N 3 LO (a N 3 LO) order in QCD. This makes use of the MSHT global PDF fitting framework, and in particular the recent theoretical advances t l;;mhat allow a PDF fit to now be performed at this order. The value of the strong coupling is found to be α S (M Z 2) (aN 3 LO) = 0.1170 ± 0.0016 . This is in excellent agreement with the NNLO value of α S (M Z 2) (NNLO) = 0.1171 ± 0.0014 , indicating that good perturbative convergence has been found. The resulting uncertainties, calculated using the MSHT dynamic tolerance procedure, are somewhat larger, but more accurate, at a N 3 LO, due to the missing higher order theoretical uncertainties that are included at this order, but not at NNLO. We in addition present a detailed breakdown of the individual dataset sensitivity to the value of the strong coupling, with special focus on the impact of fitting dijet rather than inclusive jet data. This choice is found to have a non-negligible impact, but with overall good consistency found, especially at a N 3 LO. [ABSTRACT FROM AUTHOR]

A new release of the Monte Carlo event generator Herwig (version 7.3) has been launched. This iteration encompasses several enhancements over its predecessor, version 7.2. Noteworthy upgrades include: the implementation of a process-independent electroweak angular-ordered parton shower integrated with QCD and QED radiation; a new recoil scheme for initial-state radiation improving the behaviour of the angular-ordered parton shower; the incorporation of the heavy quark effective theory to refine the hadronization and decay of excited heavy mesons and heavy baryons; a dynamic strategy to regulate the kinematic threshold of cluster splittings within the cluster hadronization model; several improvements to the structure of the cluster hadronization model allowing for refined models; the possibility to extract event-by-event hadronization corrections in a well-defined way; the possibility of using the string model, with a dedicated tune. Additionally, a new tuning of the parton shower and hadronization parameters has been executed. This article discusses the novel features introduced in version 7.3.0. [ABSTRACT FROM AUTHOR]

We present analytic results for three-loop fermionic corrections to the heavy-light form factors in perturbative quantum chromodynamics. Specifically, we present all light quark contributions and contributions from two heavy quark loops. We use the method of differential equations to compute all relevant three-loop master integrals. The results for all these contributions are expressed in terms of harmonic polylogarithms and generalized harmonic polylogarithms. [ABSTRACT FROM AUTHOR]

The violation of spatial parity symmetry () in strong interactions have never been observed experimentally. However a -breaking term can be included in the QCD Lagrangian. Hence, the local parity symmetry breaking can occur due to large topological fluctuations at high temperature with dynamic generation of nontrivial topological charge configurations. A necessary condition for observing these effects is a sufficiently large space dimension and a long lifetime of a hot drop of QCD medium, which is available in central nuclear collisions at the LHC. In order to study the effects caused by local -breaking in relativistic heavy-ion collisions we integrated them in Monte Carlo generators. Based on the analysis of the Monte Carlo data on the studied observables, taking into account the responses of the detecting systems of the ALICE facility under LHC Run 2 and Run 3 conditions, recommendations will be given on the criteria for selecting events, tracks, and choosing kinematic variables in terms of increasing sensitivity to the effects of local parity non-conservation. [ABSTRACT FROM AUTHOR]

Background: Quantitative diffusion metrics provide additional microstructural information of diseases. The robustness of quantitative diffusion metrics should be established before clinical application. Purpose: To evaluate the variability and reproducibility of quantitative diffusion MRI metrics. Study Type: Prospective. Population: 14 volunteers (7 men; median age, range, 28, 26–59 years). Field strength/Sequence: 3.0‐T/Diffusion spectrum imaging. Assessment: Brain MRI studies were performed four times per subject: involving different combinations of coil types and voxel sizes. Regions of interest of 13 brain anatomical sites were drawn by one observer twice and another observer once to allow interobserver and intraobserver reproducibility assessment. Twenty‐five quantitative metrics were calculated using four diffusion models. Statistical Tests: The variability was evaluated with coefficients of variation (CV), and quartile coefficient of dispersion (QCD). The reproducibility was assessed with intraclass correlation coefficient (ICC), and concordance correlation coefficient (CCC). Wilcoxon signed rank test was used to compare the influence of factors on robustness of quantitative diffusion metrics. A two‐tailed P < 0.05 was considered statistically significant. Results: The variability of quantitative diffusion metrics showed CV of 2.4%–68.2%, and QCD of 0.6%–48.2%, respectively. The reproducibility of scans using 20‐channel coils with voxels of 2 × 2 × 2 mm3 and 3 × 3 × 3 mm3, respectively (ICC 0.03–0.84, CCC 0.03–0.84) was significantly worse than that of repeated scans using a 20‐channel coil with a voxel size of 2 × 2 × 2 mm3 (ICC of 0.74–0.97, CCC 0.74–0.97) and that of scans using 20‐ and 64‐channel coils, respectively, with a voxel size of 2 × 2 × 2 mm3 (ICC 0.59–0.95, CCC 0.59–0.95). The intraobserver reproducibility (ICC 0.49–0.94, CCC 0.49–0.94) was significantly better than the interobserver reproducibility (ICC 0.28–0.91, CCC 0.28–0.91). Data Conclusion: Our study indicated that the voxel size has a greater influence on the reproducibility of quantitative diffusion metrics than scan‐rescans and coils. The reproducibility within one observer was higher than that between two observers. Evidence Level: 2 Technical Efficacy: Stage 1 [ABSTRACT FROM AUTHOR]

In this report, I discuss some of the most recent lattice spectroscopy calculations of hadrons and hadronic resonances involving charm quarks, with special emphasis on those that are relevant from an experimental perspective. [ABSTRACT FROM AUTHOR]

Construction of the ERLC (twin LC) collider tangential to LHC will allow investigating ep collisions at essentially higher center-of-mass energies than ERL-50 and LHC based ep collider. Luminosity estimations show that values well exceeding 1034 cm-2s-1 can be achieved for ERLC and HL-LHC based ep colliders. Certainly, proposed ep colliders have great potential for clarifying QCD basics and new physics search in addition to providing precise PDFs for adequate interpretation of the LHC experimental data. Another alternative to the ERL-50 is to construct an e-ring with the same energy and length. In this case, luminosity of order 1034cm-2s-1 can be reached. The advantage of this option is that the μ-ring can be installed instead of the e-ring as a next stage, which will allow to reach a much higher center of mass energy. [ABSTRACT FROM AUTHOR]

The possible appearance of the effects of local parity breaking in the QCD medium formed in heavy ion collisions due to violation of chiral symmetry can be quantified by corresponding chiral chemical potential μ 5 . The experimental observables sensitive to the effects of local parity violation in strong interaction include search for polarization splitting of the ρ 0 and ω 0 mesons via angular dependence of spectral functions in their decay to leptons. In this paper, we study the space-time evolution and fluctuations of μ 5 using relativistic hydrodynamics and estimate their effect on the light vector meson polarization splitting in Pb–Pb collisions at LHC energy. [ABSTRACT FROM AUTHOR]

Flux tube solutions within non-Abelian SU(3) Proca theory with external sources are obtained. It is shown that such tubes have a longitudinal chromoelectric field possessing two components (nonlinear and gradient), as well as a transverse chromomagnetic field whose force lines create concentric circles with the center on the axis of the tube. The scenario of a possible relationship between non-Abelian Proca theory and quantum chromodynamics is considered. In such scenario: (a) the components of color fields have different behavior: those which are almost classical, and those which are purely quantum; (b) the second components create a gluon condensate that is a source of the field for the almost classical components of the Proca field; (c) Proca masses may appear as a result of an approximate description of the gluon condensate; (d) the question of gauge invariance is considered. It is shown that the results obtained are in good agreement with the results of lattice calculations. We make an assumption that an approximate description of a flux tube in quantum chromodynamics can be carried out using classical Proca equations but with a mandatory account of a gluon condensate. [ABSTRACT FROM AUTHOR]

In this paper, we build on our previous work to further investigate the role of evanescent operators in gauge theories, with a particular focus on their contribution to violations of unitarity. We develop an efficient method for calculating the norms of gauge-invariant operators in Yang-Mills (YM) theory by employing on-shell form factors. Our analysis, applicable to general spacetime dimensions, reveals the existence of negative-norm states among evanescent operators. We also explore the one-loop anomalous dimensions of these operators and find complex anomalous dimensions. We broaden our analysis by considering YM theory coupled with scalar fields and we observe similar patterns of non-unitarity. The presence of negative-norm states and complex anomalous dimensions across these analyses provides compelling evidence that general gauge theories are non-unitary in non-integer spacetime dimensions. [ABSTRACT FROM AUTHOR]

The electroweak (EW) phase transition in the early Universe might be supercooled due to the presence of the classical scale invariance involving Beyond the Standard Model (BSM) sectors and the supercooling could persist down till a later epoch around which the QCD chiral phase transition is supposed to take place. Since this supercooling period keeps masslessness for all the six SM quarks, it has simply been argued that the QCD phase transition is the first order, and so is the EW one. However, not only the QCD coupling but also the top Yukawa and the Higgs quartic couplings get strong at around the QCD scale due to the renormalization group running, hence this scenario is potentially subject to a rigorous nonperturbative analysis. In this work, we employ the ladder Schwinger-Dyson (LSD) analysis based on the Cornwall-Jackiw-Tomboulis formalism at the two-loop level in such a gauge-Higgs-Yukawa system. We show that the chiral broken QCD vacuum emerges with the nonperturbative top condensate and the lightness of all six quarks is guaranteed due to the accidental U(1) axial symmetry presented in the top-Higgs sector. We employ a quark-meson model-like description in the mean field approximation to address the impact on the EW phase transition arising due to the top quark condensation at the QCD phase transition epoch. In the model, the LSD results are encoded to constrain the model parameter space. We then observe the cosmological phase transition of the first-order type and discuss the induced gravitational wave (GW) productions. We find that in addition to the conventional GW signals sourced from an expected BSM at around or over the TeV scale, the dynamical topponium-Higgs system can yield another power spectrum sensitive to the BBO, LISA, and DECIGO, etc. [ABSTRACT FROM AUTHOR]

We present a review of the conceptual basis, current knowledge, and recent progress regarding global analysis of nuclear parton distribution functions (PDFs). After introducing the theoretical foundations and methodological approaches for the extraction of nuclear PDFs from experimental data, we discuss how different measurements in fixed-target and collider experiments provide increasingly precise constraints on various aspects of nuclear PDFs, including shadowing, antishadowing, the EMC effect, Fermi motion, flavor separation, deuteron binding, and target-mass and other higher-twist effects. Particular emphasis is given to measurements carried out in proton–lead collisions at the Large Hadron Collider, which have revolutionized the global analysis during the past decade. These measurements include electroweak boson, jet, light hadron, and heavy flavor observables. Finally, we outline the expected impact of the future Electron Ion Collider and discuss the role and interplay of nuclear PDFs with other branches of nuclear, particle, and astroparticle physics. [ABSTRACT FROM AUTHOR]

We propose a model for the QCD running coupling constant based on the analytical inverse QCD coupling constant concept with an additional regularization in the low momentum region. Analyticity in the q 2 -complex plane, where q is the four-momentum transfer, is imposed by methods of the Analytic Perturbation Theory. The model incorporates a peculiar low-momentum behavior for α s (q 2) as a divergence at q 2 = 0 to retrieve color confinement, without spoiling its correct high-momentum behavior. This was achieved by means of a two-parameter regularization function, for which we considered three possible analytic expressions. In fact, within the framework of the Analytic Perturbation Theory, α s (q 2) assumes a finite value for q 2 = 0 , at all perturbative orders (infrared stability), hence the infrared divergence cannot be implemented. For this reason, we found it more straightforward to work with its reciprocal, namely, ε s (q 2) = 1 / α s (q 2) , imposing its vanishing at the origin of the q 2 -complex plane via the multiplication of the aforementioned regularizing functions and the spectral density. Once the two free parameters of the regularization functions were settled by fitting to the experimental values of α s (q 2) at the momenta where these data were available and reliable, the model could reproduce the QCD running coupling constant at any other momentum transferred. [ABSTRACT FROM AUTHOR]

Inspired by recent findings that semi-inclusive detections of heavy hadrons exhibit fair stabilization patterns in high-energy resummed distributions against (missing) higher-order corrections, we review and extend our studies on the hadroproduction of light and heavy hadrons tagged in forward and far-forward rapidity ranges. We analyze the NLL / NLO + behavior of rapidity rates and angular multiplicities via the Jethad method, where the resummation of next-to-leading energy logarithms and beyond is consistently embodied in the collinear picture. We explore kinematic regions that are within LHC typical acceptances, as well as novel sectors accessible thanks the combined tagging of a far-forward light or heavy hadron at future Forward Physics Facilities and a of central particle at LHC experiments via a precise timing-coincidence setup. [ABSTRACT FROM AUTHOR]

We evaluate thermodynamic equation of state (EOS) under one loop correction at finite chemical potential. Due to the presence of the chemical potential in the one loop correction, there is change in formation of bubble/droplet of quark-gluon plasma (QGP) and this chemical potential has the effect on the evaluation of EOS. The effect is particularly studied at the values of quark and gluon parametrization γ q = 1 / 8 and 12 γ q ≤ γ g ≤ 16 γ q at which the equilibrating bubbles/droplets sizes are obtained. The study indicates that the dynamics of the quark, anti-quark, and gluon fluids with the presence of chemical potential improves the results of the EOS from the earlier result of thermodynamic EOS without the chemical potential. It means that the effect of chemical potential in one loop correction cannot be neglected in the bubble/droplet formation of quark-gluon plasma and this chemical potential can signify the presence of a large number of charge particles in the earlier universe formation. [ABSTRACT FROM AUTHOR]

This paper discusses various aspects of the physical program Super Tau-Charm facility — a future flavor super-factory, whose construction is currently being discussed in China and Russia. Particular attention is paid to the study of charmed baryons, where record statistics Super Tau-Charm facility can provide significant progress. [ABSTRACT FROM AUTHOR]

It is believed that the core of a neutron star can be host to various novel phases of matter, from nucleon superfluid phase to exotic high baryon density quantum chromodynamics (QCD) phases. Different observational signals for such phase transitions have been discussed in the literature. Here, we point out a unique phenomenon associated with phase transition to a superfluid phase, which may be the nucleon superfluid phase or a phase like the colour-flavour locked phase, allowing for superfluid vortices. In any superfluid phase transition, a random network of vortices forms via the so-called Kibble–Zurek mechanism, which eventually mostly decays away, finally leaving primarily vortices arising from the initial angular momentum of the core. This transient, random vortex network can have a non-zero net angular momentum for the superfluid component, which will generally be oriented in an arbitrary direction. This is in contrast to the final vortices, which arise from initial rotation and hence have the initial angular momentum of the neutron star. The angular momentum of the random vortex network is balanced by an equal and opposite angular momentum in the normal fluid due to the conservation of angular momentum, thereby imparting an arbitrarily oriented angular momentum component to the outer shell of the neutron star. This will affect the pulse timing and pulse profile of a pulsar. These changes in the pulses will decay away in a characteristic manner that this as the random vortex network decays, obeying specific scaling laws leading to universal features for the detection of superfluid transitions occurring in a pulsar core. [ABSTRACT FROM AUTHOR]

Some important problems in science do not have analytical solutions in four dimensions including QCD, but they are integrable in two dimensions. For many years, scientists have been trying to find a relation between two-dimensional and four-dimensional space-time to explain the real problem in four dimensions by accurately solving the appropriate model in two dimensions. In this paper, an interesting relation between g Y M 2 (generalized two-dimensional Yang–Mills) and Maxwell construction has been found, which can be a starting point for finding more relations between two-dimensional and four-dimensional space-time, so this paper can play an important role in the advancement of science. For this purpose, first, the large-N behavior of the quartic-cubic generalized two-dimensional Yang–Mills U(N) on a sphere is investigated for finite cubic couplings. It is shown that there are two phase transitions one of which is of third order, which is similar to previous papers, and the other one is of second order, which is a novel result. Second, g Y M 2 (for G (z) = z m + λ z n ; m = 4 , 6 ; n < m ) and Maxwell construction are compared with each other and a relationship between two-dimensional space-time, which is integrable, and four-dimensional space-time is obtained. [ABSTRACT FROM AUTHOR]

In this paper, we study the 2-flavor equation of state of the quantum chromodynamics at zero temperature and finite chemical potentials with a modified Nambu–Jona–Lasinio model, where the beta equilibrium and electric charge neutrality conditions of the system (including u, d quarks, electrons and muons) are considered. The related chiral phase transition is also discussed in this paper. For comparison, we show the results with four different parameter sets, and find only quantitative differences. As chemical potential increases, the crossover instead of first-order chiral phase transition happens. Finally, we calculate the binding energy per baryon for different parameter sets, and find that the 2-flavor quark system with a smaller G 1 (or a larger m) possesses the lower binding energy per baryon, indicated to be more stable than the other case. [ABSTRACT FROM AUTHOR]

Urgent theoretical progress is needed in order to provide an estimate in the Standard Model of the recent measurement by LHCb of direct CP violation in charm-meson two-body decays. Rescattering effects must be taken into account for a meaningful theoretical description of the amplitudes involved in such category of observables, as signaled by the presence of large strong phases. We discuss the computation of the latter effects based on a two-channel coupled dispersion relation, which exploits isospin-zero phase shifts and inelasticity parameterizations of data coming from the rescattering processes ππ→ππ, πK→πK, and ππ→KK¯. The determination of the subtraction constants of the dispersive integrals relies on the leading contributions to the transition amplitudes from the 1∕NC counting, where NC is the number of QCD colors. Furthermore, we use the measured values of the branching ratios to help in selecting the non-perturbative inputs in the isospin limit, from which we predict values for the CP asymmetries. We find that the predicted level of CP violation is much below the experimental value. [ABSTRACT FROM AUTHOR]

With the explosion of data on jet-based observables in relativistic heavy-ion collisions at the Large Hadron Collider and the Relativistic Heavy-Ion Collider, perturbative Quantum Chromodynamics (pQCD)-based simulations of these processes, often interacting with an expanding viscous fluid dynamical background, have taken center stage. This review is meant to bridge the gap between theory, simulation and phenomenology of jet modification in a dense medium. We will demonstrate how the existence of such end-to-end event generators with semi-realistic or even fully realistic final states allows for the most rigorous comparisons between pQCD-based jet modification theory and experiment. State-of-the-art calculations of several jet-based observables are presented. Extensions of this theory to jets in the small systems of p–A and e–A collisions are discussed. [ABSTRACT FROM AUTHOR]

In this work, we make a study of the τ− → ωπ−ντ decay in the framework of low-energy effective field theory. The J P G decompositions of the quark currents and the ωπ final state show that, besides the Standard Model vector interaction, only the non-standard tensor interaction can have a non-zero contribution to the decay. To discuss its effect, a reliable calculation of the ωπ tensor form factors is necessary. After constructing the Lagrangian of resonance chiral theory with external tensor sources, we calculate both the vector and tensor form factors with the relevant resonance couplings determined by combining the QCD short-distance constraints, the fit to the spectral function of τ− → ωπ−ντ decay, as well as the matching between the O p 4 odd-intrinsic-parity operators after integrating out the vector resonances and the O p 6 operators of chiral perturbation theory. The new physics effect is then investigated in the distributions of the spectral function and the forward-backward asymmetry of τ− → ωπ−ντ decay. We find that the spectral function is dominated by the Standard Model, and the non-standard tensor contribution is negligible. However, since the forward-backward asymmetry can be only generated with a non-zero tensor interaction, the observable is quite sensitive to this kind of new physics. A future measurement of the observable at the Belle II experiment as well as at the proposed Tera-Z and STCF facilities is, therefore, strongly called for to check the existence of such a non-standard tensor interaction. [ABSTRACT FROM AUTHOR]

Within the widely used EvtGen framework, we have added a new event generator model for B → K*ℓ+ℓ− with improved standard model (SM) decay amplitudes and possible BSM physics contributions, which are implemented in the operator product expansion in terms of Wilson coefficients. This event generator can then be used to estimate the statistical sensitivity of a simulated experiment to the most general BSM signal resulting from dimension-six operators. We describe the advantages and potential of the newly developed 'Sibidanov Physics Generator' in improving the experimental sensitivity of searches for lepton non-universal BSM physics and clarifying signatures. The new generator can properly simulate BSM scenarios, interference between SM and BSM amplitudes, and correlations between different BSM observables as well as acceptance bias. We show that exploiting such correlations substantially improves experimental sensitivity. As a demonstration of the utility of the MC generator, we examine the prospects for improved measurements of lepton non-universality in angular distributions for B → K*ℓ+ℓ− decays from the expected 50 ab−1 data set of the Belle II experiment, using a four-dimensional unbinned maximum likelihood fit. We describe promising experimental signatures and correlations between observables. The use of lepton-universality violating ∆-observables significantly reduces uncertainties in the SM expectations due to QCD and resonance effects and is ideally suited for Belle II with the large data sets expected in the next decade. Thanks to the clean experimental environment of an e+e− machine, Belle II should be able to probe BSM physics in the Wilson coefficients C7 and C 7 ′ , which appear at low q2 in the di-electron channel. [ABSTRACT FROM AUTHOR]

We consider conformal transitions arising from the merging of IR and UV fixed points, expected to occur in QCD with a large enough number of flavors. We study the smoothness of physical quantities across this transition, being mostly determined by the logarithmic breaking of conformal invariance. We investigate this explicitly using holography where approaching the conformal transition either from outside or inside the conformal window (perturbed by a mass term) is characterized by the same dynamics. The mass of spin-1 mesons and Fπ are shown to be continuous across the transition, as well as the dilaton mass. This implies that the lightness of the dilaton cannot be a consequence of the spontaneous breaking of scale invariance when leaving the conformal window. Our analysis suggests that the light scalar observed in QCD lattice simulations is a q q ¯ meson that becomes light since the q q ¯ -operator dimension reaches its minimal value. [ABSTRACT FROM AUTHOR]

We study the small-mass asymptotic behavior of so-called angular integrals, appearing in phase-space calculations in perturbative quantum field theory. For this purpose we utilize the strategy of expansion by regions, which is a universal method both for multiloop Feynman integrals and various parametric integrals. To apply the technique to angular integrals, we convert them into suitable parametric integral representations, which are accessible to existing automation tools. We use the code asy.m to reveal regions contributing to the asymptotic expansion of angular integrals. To evaluate the contributions of these regions in an epsilon expansion we apply the method of Mellin-Barnes representation. Our approach is checked against existing results on angular integrals revealing a connection between contributing regions and angular integrals constructed from an algebraic decomposition. We explicitly calculate the previously unknown asymptotics for angular integrals with three and four denominators and formulate a conjecture for the leading asymptotics and the pole part for a general number of denominators and masses. [ABSTRACT FROM AUTHOR]

The static properties and dynamic evolution of bottomonium states in a hot QCD medium are investigated through the Schrödinger equation with complex heavy quark potentials, which have been presented recently in a lattice QCD study and with three different extractions. This approach builds a direct connection between the in-medium heavy quark potentials from the lattice QCD to the experimental observables. The yields and nuclear modification factors R AA of bottomonium in Pb–Pb collisions at s NN = 5.02 TeV are calculated in this work. Our results show a large suppression of the bottomonium yield in heavy ion collisions due to the large imaginary potential. To understand bottomonium R AA based on lattice QCD potentials, we propose a formation time for bottomonium states and find that experimental data can be well explained with the heavy quark potential extracted by the Padé fit, which shows no color screening in the real part potential. [ABSTRACT FROM AUTHOR]

Below, we present a brief review of the recent studies of the polarized Bjorken sum rule for small values of . Our careful analysis reveals an excellent agreement between the experimental data and the predictions recently obtained in the framework of analytic QCD. Well-known perturbative expressions for coupling constant on the contrary lead to a strong difference between these data and turn out to be inapplicable. To estimate calculated phenomenological values, we discussed the photoproduction limit. [ABSTRACT FROM AUTHOR]

We show that dynamical gluon and quark solutions possess inherent color symmetry with respect to Weyl group of . Such a symmetry manifests itself in the space of physical solutions after removing all pure gauge degrees of freedom, and it leads to existence of invariant non-degenerate vacuum and one-particle quantum states for gluons and quarks. Some physical implications are discussed. [ABSTRACT FROM AUTHOR]

The production of polarized mesons at the NICA (Nuclotron based Ion Collider fAcility) energy of GeV is studied on the basis of the generalized parton model in the leading order of perturbative QCD. The hadronization of a quark pair to a meson is described within the model of nonrelativistic QCD. Nonperturbative model parameters are determined on the basis of a comparison with available experimental data on the production of prompt mesons at the energies of GeV (NA3) and GeV (PHENIX). [ABSTRACT FROM AUTHOR]

Interest in studying multiparticle-production processes in lepton and hadron interactions has not faded to date. The development of strong-interaction theory in the form of quantum chromodynamics (QCD) permits describing these interactions at the level of quarks and gluons. The transition from partons to observed hadrons at the hadronization stage is very difficult. The gluon-dominance model describing multiparticle production of secondaries and including the hadronization stage is proposed in the present study. This model is applied to describing electron–positron annihilation. It confirms an active role of the gluon component in the formation of secondaries, is indicative of the fragmentation mechanism of hadronization occurring in a vacuum, and describes experimental data on multiplicity distributions. [ABSTRACT FROM AUTHOR]

We review recent theoretical developments relevant to heavy-ion experiments carried out within the Beam Energy Scan program at the Relativistic Heavy Ion Collider. Our main focus is on the description of the dynamics of systems created in heavy-ion collisions and establishing the necessary connection between the experimental observables and the QCD phase diagram. [ABSTRACT FROM AUTHOR]

Jet substructure observables hold the keys to identifying the inner working of the quark–gluon plasma through its imprints in jet modification patterns. Because of the multi-scale nature of jet evolution, the strategy has focused on developing jet reclustering-based and jet shape-based observables to specifically probe different stages of jet evolution, which provide multi-dimensional quantification of jet particle distribution phase spaces. The developments of jet substructure in the past few years allowed us to explore the correlations among jet observables. The richer information beyond single-observable modifications could give provides a crucial step beyond the energy loss paradigm. This review surveys the theory and phenomenology of modern jet substructure observables, which help constraining the energy scales of medium interactions and identifying heavy flavor quarks within jets. Also, the peculiar soft activities point to more refined studies of medium responses to jets. [ABSTRACT FROM AUTHOR]

We make an analysis of r.m.s. and charge radii of heavy flavored mesons introducing the three-loop correction to the static potential V (r) = - 4 α s 3 r + b r . Considering linear as parent and Coulomb as perturbation, the first order wave function is used to study the corresponding correction in coordinate space. The wave function is then used to study the r.m.s. and charge radii of heavy flavored mesons. The computed results are then compared with the data available in literature. The results show significant improvements compared to our earlier works. [ABSTRACT FROM AUTHOR]

This review focuses on diffractive physics, which involves the long-range interactions of strong nuclear force at high energies described by SU(3) gauge symmetry. It is expected that diffractive processes account for nearly 40% of the total cross-section at LHC energies. These processes consist of soft-scale physics where perturbation theory cannot be applied. Although highly successful and often described as a perfect theory, quantum chromodynamics relies heavily on perturbation theory, a model best suited for hard-scale physics. The study of pomerons could help bridge the soft and hard processes and provide a complete description of the theory of the strong interaction across the full momentum spectrum. Here, we will discuss some of the features of diffractive physics, experimental results from SPS, HERA, and the LHC, and where the field could potentially lead. With the recent publication of the odderon discovery in 2021 by the D0 and TOTEM collaborations and the new horizon of physics that lies ahead with the upcoming Electron-Ion Collider at Brookhaven National Laboratory, interest is seemingly piquing in high energy diffractive physics. [ABSTRACT FROM AUTHOR]

ARIADNE (Axion Resonant InterAction Detection Experiment) is a table-top experiment that intends to search for QCD axions from exotic spin-dependent interactions mediated by axion between nuclei at sub-mm range. This experiment includes a non-magnetic mass to source the axion field, and a dense ensemble of hyper-polarized 3He nuclei to detect the axion field with nuclear-magnetic-resonance (NMR)-based method. The expected NMR signal from the interaction could be easily buried in the noise spectrum of the magnetometer, especially in a frequency range (~ 100 Hz) where the interaction signal is supposed to exist. In this work, we report optimization of SQUID gradiometer for ARIADNE including noise spectrum measurement. [ABSTRACT FROM AUTHOR]

In this work, the doubly-charm and doubly-bottom pentaquark molecular states D (∗) Σ c (∗) and B (∗) Σ b (∗) are studied via the QCD sum rules. Sixteen color singlet-singlet type currents with the definite isospin-spin-parity I J P are constructed to interpolate the corresponding hadronic states with the same quantum numbers. The masses and pole residues of those doubly-heavy pentaquark molecular states are calculated, the results show that their masses are all below the corresponding meson-baryon thresholds, which means that they are possible bound states, not resonant states, moreover, the possible decay channels for the doubly-charm molecular states are given. [ABSTRACT FROM AUTHOR]

Lattice gauge theory should be able to address significant new scientific questions when implemented on quantum computers. In practice, error-mitigation techniques have already allowed encouraging progress on small lattices. In this work we focus on a truncated version of SU(2) gauge theory, which is a familiar non-Abelian step toward quantum chromodynamics. First, we demonstrate effective error mitigation for imaginary time evolution on a lattice having two square plaquettes, obtaining the ground state using an IBM quantum computer and observing that this would have been impossible without error mitigation. Then we propose the triamond lattice as an expedient approach to lattice gauge theories in three spatial dimensions and we derive the Hamiltonian. Finally, error-mitigated imaginary time evolution is applied to the three-dimensional triamond unit cell, and its ground state is obtained from an IBM quantum computer. Future work will want to relax the truncation on the gauge fields, and the triamond lattice is increasingly valuable for such studies. When implemented on quantum computers, lattice gauge theory should be able to address significant new scientific questions about quarks and gluons. The authors of this paper replace the traditional Cartesian lattice by one that has unique symmetry properties, and they use this new lattice to perform an error-mitigated quantum computer calculation. [ABSTRACT FROM AUTHOR]

In this paper, we present our QCD analysis of the Nucleon Form Factors presented by JLab to extract a new parameterization for the valence Generalized Parton Distributions (GPDs), H v q (x , ξ = 0 , t) and E v q (x , ξ = 0 , t). We choose simple parameterizations for x − and t − dependence of GPDs at zero skewness. These free parameters of the model are then obtained using old and new data of nucleon's elastic electromagnetic form factors (FFs) from JLAB. We have also used the "Hessian method" to perform a careful estimation of the uncertainties for the nucleon GPDs and corresponding observables originate from experimental errors. We also calculate the parton distribution functions (PDFs) in Impact parameter space to show the 3D structure of the Nucleon. We also calculated the proton and the neutron charge densities ρ ch (p , n) . We show that there is a highly localized negative charge near the center of the neutron and it is because of the negatively charged down quarks dominating the high momentum quarks in the neutron. Finally using the obtained Dirac's FF, we had an estimation for the proton charge radius. The predictions based on the obtained nucleon GPDs are in good agreement with all available experimental data and other phenomenological models. [ABSTRACT FROM AUTHOR]

This review aims at providing an extensive discussion of modern constraints relevant for dense and hot strongly interacting matter. It includes theoretical first-principle results from lattice and perturbative QCD, as well as chiral effective field theory results. From the experimental side, it includes heavy-ion collision and low-energy nuclear physics results, as well as observations from neutron stars and their mergers. The validity of different constraints, concerning specific conditions and ranges of applicability, is also provided. [ABSTRACT FROM AUTHOR]

We present a comprehensive review of the theoretical and experimental progress in the investigation of novel high-temperature quantum chromodynamics phenomena in small systems at both the Relativistic Heavy Ion Collider and the Large Hadron Collider. We highlight the challenges and opportunities associated with studying small systems, by which we generally mean collision systems that involve at least one light ion or even a photon projectile. We discuss perspectives on possible future research directions to better understand the underlying physics at work in the collisions of small systems. [ABSTRACT FROM AUTHOR]

We investigate the origin of next-to-leading power (NLP) corrections to the event shapes' thrust and c-parameter, at next-to-leading order. For both event shapes, we trace the origin of such terms in the exact calculation, and compare with a recent approach involving the eikonal approximation and momentum shifts that follow from the Low–Burnett–Kroll–Del Duca (LBKD) theorem. We assess the differences both analytically and numerically. For the c-parameter both exact and approximate results are expressed in terms of elliptic integrals, but near the elastic limit it exhibits patterns similar to the thrust results. [ABSTRACT FROM AUTHOR]

Using the dispersive method we perform a two-loop analysis of the leading non-perturbative power correction to the change in jet transverse momentum pT, in the small R limit of a Cambridge-Aachen jet clustering algorithm. We frame the calculation in such a way so as to maintain connection with the universal "Milan factor" that corrects for the naive inclusive treatment of the leading hadronization corrections. We derive an enhancement factor that differs from the universal Milan factor computed for event-shape variables as well as the corresponding enhancement factor previously derived for the kt algorithm. Our calculation directly exploits the soft and triple-collinear limit of the QCD matrix element and phase space, which is relevant for capturing the coefficient of the leading 1/R power correction. As an additional check on our approach, we also independently confirm the known result for the kt algorithm. [ABSTRACT FROM AUTHOR]

We present a state-of-the-art calculation of the unpolarized pion valence-quark distribution in the framework of large-momentum effective theory (LaMET) with improved handling of systematic errors as well as two-loop perturbative matching. We use lattice ensembles generated by the MILC collaboration at lattice spacing a ≈ 0.09 fm, lattice volume 643 × 96, N f = 2 + 1 + 1 flavors of highly-improved staggered quarks and a physical pion mass. The LaMET matrix elements are calculated with pions boosted to momentum P z ≈ 1.72 GeV with high-statistics of O (106) measurements. We study the pion PDF in both hybrid-ratio and hybrid-regularization-independent momentum subtraction (hybrid-RI/MOM) schemes and also compare the systematic errors with and without the addition of leading-renormalon resummation (LRR) and renormalization-group resummation (RGR) in both the renormalization and lightcone matching. The final lightcone PDF results are presented in the modified minimal-subtraction scheme at renormalization scale μ = 2.0 GeV. We show that the x -dependent PDFs are compatible between the hybrid-ratio and hybrid-RI/MOM renormalization with the same improvements. We also show that systematics are greatly reduced by the simultaneous inclusion of RGR and LRR and that these methods are necessary if improved precision is to be reached with higher-order terms in renormalization and matching. [ABSTRACT FROM AUTHOR]

We investigate the leading twist generalized transverse momentum dependent parton distributions (GTMDs) of the unpolarized and longitudinally polarized gluons in the nucleon. We adopt a light-front gluon-triquark model for the nucleon motivated by soft-wall AdS/QCD. The gluon GTMDs are defined through the off-forward gluon-gluon generalized correlator and are expressed as the overlap of light-cone wave functions. The GTMDs can be employed to provide the generalized parton distributions (GPDs) by integrating out the transverse momentum. The Fourier transform of the GPDs encodes the parton distributions in the transverse position space, namely, the impact parameter dependent parton distributions (IPDs). We also calculate the three gluon IPDs corresponding to the GPDs H g , E g and H ~ g , and present their dependence on x and b ⊥ , respectively. [ABSTRACT FROM AUTHOR]

We derive a Nambu–Jona-Lasinio (NJL) model from a non-local gauge theory and show that it has confining properties at low energies. In particular, we present an extended approach to non-local QCD and a complete revision of the technique of Bender, Milton and Savage applied to non-local theories, providing a set of Dyson–Schwinger equations in differential form. In the local case, we obtain closed-form solutions in the simplest case of the scalar field and extend it to the Yang–Mills field. In general, for non-local theories, we use a perturbative technique and a Fourier series and show how higher-order harmonics are heavily damped due to the presence of the non-local factor. The spectrum of the theory is analysed for the non-local Yang–Mills sector and found to be in agreement with the local results on the lattice in the limit of the non-locality mass parameter running to infinity. In the non-local case, we confine ourselves to a non-locality mass that is sufficiently large compared to the mass scale arising from the integration of the Dyson–Schwinger equations. Such a choice results in good agreement, in the proper limit, with the spectrum of the local theory. We derive a gap equation for the fermions in the theory that gives some indication of quark confinement in the non-local NJL case as well. Confinement seems to be a rather ubiquitous effect that removes some degrees of freedom in the original action, favouring the appearance of new observable states, as seen, e.g., for quantum chromodynamics at lower energies. [ABSTRACT FROM AUTHOR]