The quest for sources of the simultaneous violation of C and CP symmetry was popular in the 1960s and has since been mostly neglected. We revisit the operators that break C and CP for flavor-conserving transitions in both the Standard Model effective field theory and the low-energy effective field theory. Subsequently, we match these quark operators to light-meson physics using chiral...
Recent progress in studying nucleon resonances using lattice QCD is presented. Systems involving meson-baryon scattering, such as the Lambda(1405) resonance, and baryon-baryon scattering are discussed.
We review the determination of the low-energy pion-nucleon scattering amplitude using Roy-Steiner equations. In particular, we focus on the extraction of nucleon resonances and address some of the most frequently asked questions regarding our analysis. Finally, we also discuss the phenomenological determination of the pion-nucleon $\sigma$-term, derived in combination with modern precision...
Two-pole structures refer to the fact that two dynamically generated states are located close to each other between two coupled channels and have a mass difference smaller than the sum of their widths. Thus, the two poles overlap in the invariant mass distribution of their decay products, creating the impression that only one state exists. This phenomenon was first noticed for the Lambda(1405)...
Any effective field theory relies on a certain power counting that allows one to perform a systematic expansion of calculated quantities in terms of some soft scales. However, a naive power counting can be violated due to the presence of various hard scales in the scheme. A typical example of such a scale is an ultraviolet regulator. This issue is particularly challenging when the...
The first excited state of the nucleon dominates many nuclear phenomena at energies above the pion-production threshold and plays a prominent role in the physics of the strong interaction. The study of the N to $\Delta$ transition form factors (TFFs) allows to shed light on key aspects of the nucleonic structure that are essential for the complete understanding of the nucleon dynamics. In this...
In this talk, we will review the theory underlying the chiral anomaly $\gamma \pi \to \pi \pi$. This includes its extractions based on dispersion relations, lattice QCD and the constraints from the crossed channel $\gamma^* \to 3\pi$.
In this talk we discuss how the chiral effective Lagrangian is generalized systematically to curved spacetime and how the corresponding energy-momentum tensor (EMT) is obtained. As next, we discuss the nucleon and delta gravitational form factors, which are described by the diagonal hadronic matrix elements of the EMT at low energies. Furthermore, we discuss the transition gravitational form...
Electromagnetic polarizabilities are fundamental properties of composite systems, and measure the 'stiffness' of a system to electromagnetic deformation. Measurements of hadron polarizabilities provide a test of effective field theories, dispersion theories, and lattice calculations. While significant progress has been made in measuring proton polarizabilities, with uncertainties at the level...
Theorists love the unitarity limit: the $NN$ $S$-wave binding energies are zero, the scattering lengths infinite, and one has more symmetries. In "pionless" EFT, Efimov's $3N$ scale sets the only low-energy scale of all observables for a convergent, perturbative expansion around the unitarity limit. There are strong hints that Nuclear Physics resides indeed in a sweet spot: bound weakly enough...
The chiral Lagrangian provides a modern paradigm to build nuclear forces and nuclear currents for external probes. Higher-order chiral forces tend to have more complicated structures despite their smaller effects. We present our recent results in developing perturbatiion theories for higher-order chiral forces while iterating the leading-order interactions nonperturbatively. In particular, we...
We present the results of a partial wave analysis of the global real Compton scattering (RCS) database, extracting the leading scalar and spin polarisabilities of the proton.
Exploring the nucleon using electromagnetic probes reveals a fine and intricate interplay between its various structural properties. As an example, the nucleon polarisabilities encode the two-photon response, such as...
One of the most preplexing predictions of Chiral Perturbation Theory is the negative electric polarizability of the neutral pion. We revisit this problem and argue that in an ultraviolet-complete calculation the polarizabilty is positive. A novel light-front QCD calculation will be presented, corroborating this point.
Chiral effective field theory ($\chi$EFT) is an approach to describe the force between nucleons as arising from the more fundamental principles of quantum chromodynamics. A vital part is to have a power counting (PC) that quantifies the relative importance of the EFT order-by-order contributions to nuclear observables. The definition of the PC is not unique, and the fact that nuclear systems...
With the existing 10 billion J/psi events accumulated at BESIII, the high production of long-lived baryons in J/psi decays serves as a novel source of hyperon beams, which open a unique opportunity for exploring the hyperon-nucleon interactions. By studying these hyperons with the beam pipe and the inner tube of the MDC detector, the recent results, including interactions of $\Lambda p$,...
Precision calculations of flavour physics processes such as leptonic decays of pions and kaons allow for indirect searches of new physics. For instance, the Cabibbo-Kobayashi-Maskawa matrix elements $|V_{ud}|$ and $|V_{us}|$ accessible in these decays satisfy a unitarity relation within the Standard Model that can be probed with lattice QCD simulations. With a goal of (sub-)percent precision,...
The rare radiative $K^+\to\pi^+\ell^+\ell^-$ decays ($\ell=e,\mu$) provide experimental access to the $K^+\to\pi^+\gamma^*$ transition. The relevant form factor is conventionally written in terms of two hadronic parameters, $a_+$ and $b_+$, which are being measured by NA62 in both electron and muon channels. Comparing the two channels allows for a stringent test of lepton-flavor universality....
The well-established $\Lambda(1405)$ hyperon with $J^\pi = \frac{1}{2}^-$ may be a dual structure consisting of two overlapping $I=0$ resonances. Each resonance may couple to $\Sigma\pi$ and $N\overline{K}$ final states, but a direct measurement of these two decays for each resonance has not previously been done. Using the GlueX detector system at Jefferson Lab we have obtained high...
The leading and subleading three-pion exchange potentials have so far only been derived in chiral EFT by Norbert Kaiser using S-matrix matching. However, nuclear potentials are scheme-dependent quantities, and it is not a priori clear if the available results are consistent with the interactions and currents derived by the Bochum group using a different technique, the so-called Method of...
We study nucleon-nucleon interaction up to next-to-next-to-leading order (NNLO) by applying time-ordered perturbation theory (TOPT) to covariant chiral effective field theory. Diagrammatic rules of TOPT, for the first time, are worked out for particles with non-zero spin and interactions involving time derivatives. We define the effective potential as a sum of two-nucleon irreducible...
Hypernuclei provide important information to constrain the hyperon-nucleon (YN) and three-baryon (YNN) interactions. In this contribution, we will discuss our recent results obtained using chiral YN [1,2] and chiral YNN interactions for light hypernuclei up to $A=8$.
We use the hypernuclei data to determine the charge-symmetry breaking (CSB) of YN interactions and for exploring the results...
Whether one is interested in measuring transition matrix elements or extracting scattering parameters, a common requirement is to constrain and determine an analytical expression for the scattering amplitude. A systematically improvable, well developed theoretical method is to determine the finite volume spectrum using lattice QCD and connect it to the infinite volume scattering amplitude...
The decays of the light meson π0, η and η′ offer a flavor-conserving laboratory to assess the low-energy QCD and to search for new physics Beyond the Standard Model. The QCD symmetries and symmetry breakings at low-energy, such as the chiral symmetry or the axial anomalies, are manifested in their most unambiguous form in the sector of light pseudoscalar mesons. An experimental study of...
Study of isolated multi-neutron systems is one of fundamental subjects in nuclear physics. In several decades, experimental attempts have made with a particular focus on the tetra-neutron system. Among them, two experiments, the double-charge exchange reaction on ${}^4$He and the alpha-particle knockout reaction from the ${}^8$He, show a sharp peak structure just above the threshold in the...
The pseudoscalar $\eta$ and $\eta'$ mesons play a special role in the context of chiral dynamics as their physics properties are intimately linked to the chiral anomaly. While the $\eta$ meson would be a massless state in a $SU(3)$ flavor symmetric world like the other pseudoscalar octet mesons, the $\eta'$ remains massive even in the chiral limit due to the anomalous breaking of the axial...
A coupled-channel approach is applied to the charged tetraquark state $T_{cc}$ discovered by the LHCb Collaboration and the lattice data. Special attention is paid to the three-body and left-hand cut for the physical and unphysical pion mass cases, respectively. We discuss the lattice data to stress a potentially strong impact of left-hand cuts from the one-pion exchange on the pole extraction...
I will discuss scalar and tensor charmonium resonances determined using lattice QCD. Working at $m_\pi\approx 391$ MeV, more than 200 finite-volume energy levels are computed and these are used in extensions of the Lüscher formalism to determine infinite volume scattering amplitudes. Working in the approximation where charm-annihilation is forbidden, the ground state $\chi_{c0}(1P)$ and...
Hyperon-proton scattering experiment is one of the most direct methods to study the hyperon-nucleon interaction, as in the case of the $NN$ interaction. Although it had been experimentally difficult for a long time due to short lifetime of hyperons, we successfully performed novel high-statistics $\Sigma^\pm p$ scattering experiment at J-PARC (J-PARC E40 experiment). The main physics...
We performed a theoretical analysis of the semileptonic decays $\eta^{(\prime)} \to \pi^0 \ell^+ \ell^-$ and $\eta' \to \eta \ell^+ \ell^-$, where $\ell = e, \mu$, via a charge-conjugation-conserving two-photon mechanism. The underlying form factors are modeled using vector-meson dominance, phenomenological input, and $U(3)$ flavor symmetry. We considered both a monopole and a dipole model,...
The uncertainty of the Standard Model prediction of the anomalous magnetic moment of the muon $g-2$ is dominated by hadronic contributions. As part of these hadronic inputs, the pseudoscalar-pole contribution in hadronic-light-by-light scattering plays a vital role. The currently sought precision of the Standard Model prediction of $(g-2)_μ$ requires a careful evaluation not only of the...
We employ a chiral effective field theory-based approach to connect $DD^*$ scattering observables at the physical and variable pion masses accessible in lattice QCD simulations. We incorporate all relevant scales associated with three-body $DD\pi$ dynamics and the left-hand cut induced by the one-pion exchange for pion masses higher than the physical one, as required by analyticity and...
It is important to study multi-neutron system for T=3/2 three nucleon force. For this purpose, I have been studying tetra neutron system, 7H etc. In this talk, I introduce recent study of these study. I also introduce my future study: up to 10-body system calculation with chral EFT force.
The sector of decay constants of the octet of light pseudoscalar mesons in the framework of 'resummed' $SU(3)$ chiral perturbation theory is investigated. A theoretical prediction for the decay constant of $\eta$-meson is compared to a range of available determinations. Compatibility of these determinations with the latest fits of the $SU(3)$ low energy coupling constants is discussed. Using a...
The scattering lengths on the interactions between the spin-1/2 doubly charmed barons and Nambu-Goldstone bosons are of great importance for the investigation of the spectroscopy of the doubly charmed baryons. On the one hand, the S- and P-wave scattering lengths are predicted in a manifestly relativistic baryon chiral perturbation theory at leading one-loop order. On the other hand, results...
We have been performing calculations [1] using the SMS chiral potential [2] for NN interactions, the Juelich NLO19 chiral potential [3] for YN interactions, and the YNN three-body force [4] as inputs for the Faddeev three-body equations of Hypertriton. For the YNN three-body force, not only a two-pion exchange type but also one-pion exchange and contact types were adopted. Partial wave...
Our current understanding of hadrons is through QCD, and confinement in QCD leads to a rich spectrum of hadrons. Experimentally, hadronic resonances can appear as peaks in the invariant mass distributions. However, universal parameters of hadronic resonances are encoded theoretically in the poles of the $S$-matrix. Still, not all observed peaks necessarily correspond to hadronic...
A reliable estimation of the accuracy of theoretical calculations is crucial for meaningful comparisons with experimental data. In the framework of chiral Effective Field Theory (EFT), one significant source of theoretical error stems from truncating the EFT expansion, which accounts for the impact of neglected higher-order terms. Past studies have typically estimated truncation uncertainty by...
Vector-meson exchange can be naturally introduced for both quark and hadron interactions in the framework of the hidden local symmetry (HLS) for the chiral dynamics. In the studies of Pc hadronic molecules [1,2] and whole spectrum of hadronic ground states [3,4], the vector meson exchanges are found to play more important role to reproduce the data than pseudoscalar meson exchanges, with many...
The finite-volume Lüscher formalism and its extensions provide a powerful method for extracting scattering amplitudes and resonance properties in lattice QCD calculations. The finite-volume energies used in the approach must satisfy an upper bound, i.e. they must be below the lowest multi-particle threshold not explicitly considered in the derivation. Ignoring this would lead to incorrect...
Studying three hadron dynamics using lattice QCD enables first-principles predictions of various hadronic resonances, including the Roper and the doubly-charmed tetraquark. To achieve this, substantial progress has been made in developing, implementing, and applying theoretical tools that connect finite-volume quantities to infinite-volume amplitudes involving three particles. In this...
In this talk, I will discuss the physics program of the low-energy, high-intensity electron accelerator MESA, currently under construction at the Institute for Nuclear Physics in Mainz. Designed to support a comprehensive physics program, MESA will facilitate three distinct experiments. An external beamline will deliver spin-polarized electrons to the P2 experiment, with the major goal of...
In recent years the use of nuclei has become increasingly relevant for experiments studying fundamental parameters of electroweak interactions. For experimental success, reliable theoretical inputs with well-controlled errors are required. Currently chiral effective field theory is one of the most adept theory fulfilling this requirement. In order to use this theory as a tool for studying...
A central goal of nuclear theory is to comprehensively explain the diverse phenomena and unique characteristics observed in nuclear systems through a microscopic framework. In this framework, nucleons interact with each other via two and many-body effective interactions, and with external electroweak probes via effective current operators. These interactions and currents form the core inputs...
Necessity of the three-nucleon forces (3NFs) have come to light in various nuclear phenomena, for example, binding energies of nuclei, and equation of state in nuclear matters. As numerically exact solutions of the Faddeev equations using 2N- and 3N-forces are now attainable for observables in nucleon-deuteron (Nd) scattering, intricate information of the 3NFs can be extracted by directly...
In this talk I review established as well as recently uncovered connections between string-derived scalar amplitudes (Z-theory) and amplitudes of pions in the chiral non-linear sigma model (NLSM). Non-abelian Z-theory [1] amplitudes generalize the open string Veneziano amplitude and represent a stringy completion (including corrections in the string scale $\alpha$') of a cubic bi-adjoint field...
Three-nucleon systems offer fundamentals to determine the basic properties of three-nucleon forces (3NFs), such as the strength of the force. In contrast, many-nucleon systems are major playground of three-nucleon forces, as evidenced by, for example, spectroscopic properties of light nuclei, dripline determination, and nuclear-matter saturation.
In this presentation, we delve into the...
We propose the Gauge Theory Bootstrap --- a method to compute the pion S-matrix that describes the low energy physics of the strong interaction and other similar gauge theories. Using this method, we compute pion scattering phase shifts for all partial waves with angular momentum $\ell \le 3$ up to $2$ GeV and calculate the low energy $\chi$PT coefficients $L_{1,2,4,6}$. The method looks for...
Our work focused on studying the scattering length of $J/\psi N$ under gluon exchange via dispersion relations and compared the results with contributions from existing coupled-channel processes. Starting from the SU(3) tree-level chiral amplitudes of $N\bar{N}\to\pi\pi/K\bar{K}$, we obtained the $S$-wave amplitude considering the final state interactions of the $\pi\pi$-$K\bar{K}$ coupled...
The baryon-meson scattering amplitude is calculated under the formalism of $1/N_c$ expansion of QCD. The obtained results consider the effects of the decuplet-octet baryon mass difference and perturbative flavor $SU(3)$ symmetry breaking in the complete computation for the first time. Since the resulting expressions can be applied to any baryons and mesons, when the Gell-Mann - Nishijima...
The ongoing progress in derivation the chiral two- and many-nucleon forces in the framework of chiral perturbation theory (χPT) [1,2] gives better and better understanding of nuclear phenomena, but also brings many challenges for application of these forces beyond the two-nucleon (2N) system. While general operator form of three nucleon force (3NF) is currently known up to N4LO [3-6], its...
Using the most recent experimental data and lattice calculations of scattering lengths of $\pi\pi$ scattering and employing dispersive representation of the amplitude based on Roy equations, we compute the subthreshold parameters of this process. We use Monte Carlo sampling to numerically model the probability distribution of the results based on all uncertainties in the inputs. In the second...
Scattering experiments in systems of three nucleons provide particularly rich and sensitive data for testing the state-of-the-art potentials of nuclear interactions. Experimental studies of the deuteron breakup reaction demonstrated sensitivity of the observables to three-nucleon force (3NF) and but also the importance of the Coulomb interaction between protons even at beam energies close to...
Three-hadron systems are an active topic in lattice QCD, primarily due to their relevance to the study of hadronic resonances with three-body decays. The systematics of such challenging systems -- finite-volume effects and the pion-mass dependence -- can be connected to the elastic three-to-three scattering amplitude, which can in turn be computed in chiral perturbation theory. I describe a...
We discuss various aspects of (multi-) Higgs boson production from longitudinal electroweak gauge bosons $W_L W_L \to n \times h$ in the TeV region as the necessary information to characterise the Flare function, $\mathcal{F}(h)$, which determines whether the Standard Model EFT (SMEFT) or the Higgs EFT (HEFT -also sometimes referred as the EW Chiral Lagrangian-) is the appropriate description....
We consider the three-nucleon system non-perturbatively in the framework of chiral effective field theory (EFT) on the lattice at next-to-next-to-next-to-leading order ($\mathrm{N^3LO}$). For the two-nucleon force, a lattice version of the successful semilocal momentum-space regularized (SMS) potential is employed. In the three-nucleon sector, we determine the two low-energy constants (LECs)...
The nucleon self-energy is calculated in SU(2) covariant chiral perturbation theory (ChPT) to analyze the pion mass dependence of the nucleon mass up to chiral order $\mathcal{O}(q^6)$, i.e., including two-loop diagrams. In a first step, all diagrams are expressed by a small set of (scalar) master integrals. The extended on-mass-shell (EOMS) renormalization scheme is applied, where (next to...
Hypergeometric function theory and Feynman Integral calculus go hand in hand. A series of recent investigations that culminated in the construction of several Mathematica packages that are based on Mellin-Barnes techniques, Method of Regions, hypergeometric function theory, etc., is reviewed in this talk to encourage the community to explore the use of these packages. Two-loop integrals...
Pionless effective field theory (EFT) represents a highly convenient tool that allows the description of nuclear interaction at very low energies. This theory, at its leading order, has been used to study various systems up to ${}^{16}$O; however, only with limited success, rendering $A > 4$ nuclei unbound in the large cutoff limit. Higher orders of the theory have been mostly tested in $A...
Nonleptonic hyperon transitions are studied in a relativistic framework of chiral perturbation theory ($\chi$PT). Previously, one-loop corrections to parity-violating and -conserving partial-wave amplitudes S and P have been computed in a nonrelativistic approach, focusing on the leading chiral logarithms [1]. This study concluded that a satisfying agreement with data and reasonable...
One of the fundamental problems in nuclear physics is to understand the properties of nuclei based on underlying nuclear interactions. The nuclear interactions determined with the few-body data can be tested by computing the heavier systems. The tested interactions can be used to predict the experimentally yet unknown properties. For this purpose, developing many-body techniques for heavier...
The presence of the long-range forces brings novel aspects in the formulation of the finite-volume two-body quantization condition, which relates the lattice spectrum with the infinite-volume scattering phase shifts. In particular, the higher partial waves start to contribute substantially to the quantization condition that makes the analysis more complicated. Furthermore, the so-called...
The GlueX detector in the experimental Hall-D at Jefferson Lab offers a unique opportunity to perform a measurement of the decay width of eta mesons through the Primakoff effect. The experiment complements the physics program at Jefferson Lab on measuring the decay width of light pseudoscalar mesons via the Primakoff process. The goal of the experiment is to measure differential cross sections...
Fragmentation Function (FF) plays a crucial role in describing the hadronization process. We report the measurements of normalized differential cross sections of inclusive pi0, Ks, and eta production as a function of hadron momentum at six energy points with $q^2$ transfer from 5 to 13 GeV${}^2$ at BESIII. The results of pi0 and Ks with a relative hadron energy coverage from 0.1 to 0.9...
In this talk, I will present a novel effective-field-theory-based approach for extracting two-body scattering information from finite volume energies. By explicitly incorporating one-pion exchange, we overcome the challenging left-hand cut problem in Lüscher’s method and can handle finite volume energy levels both below and above the left-hand cut. Additionally, we utilize the plane wave basis...
We present in this talk the most recent progresses made within the framework of chiral effective field theory for few-nucleon structure and low-energy reactions, especially those of astrophysical interest. We will first review the studies of the A=2 proton-proton fusion [1], as well as the muon capture on deuteron [2]. Furthermore, using the Hyperspherical Harmonics ab-initio method, we will...
We introduce a novel method that utilizes the overlaps between test states and Hamiltonian eigenstates to determine resonance positions, applicable both in lattice and in finite-volume continuum calculations. We demonstrate the efficiency of this method through explicit examples. Using simple spatially compact test states, we obtained Breit-Wigner peaks in the energy distribution for the...
By considering the one loop background field method for the quark-antiquark interaction mediated by non perturbative one-gluon exchange, U(3) flavor dependent corrections to the NJL-model coupling constant are derived in the local limit. Meson and quark mixing(s) are discussed, basically emerging due to the different representations in which quarks and quark-antiquark meson are defined. These...
Within the Generalized Contact Formalism [1], I will present a study of short-range correlations and contact coefficients [2], utilizing realistic chiral potentials, derived either in coordinate-space, and therefore local, or in momentum-space, and therefore non-local. Additionally, we employ the Hyperpherical Harmonics method [3] to calculate the two-body momentum distribution with virtually...
We use a combination of effective field theory and the renormalization group to determine the impact of radiative corrections on the nucleon-nucleon potential. In order to do so, we present a modified version of pionless effective field theory inspired by earlier work in nonrelativistic quantum electrodynamics. We investigate the effect of the corrections on the binding energy, electromagnetic...
During the talk, I will discuss progress in applying the relativistic three-particle scattering formalism of Hansen and Sharpe to systems of non-degenerate mesons of arbitrary angular momenta. For concreteness, I will focus on the $DD\pi$ system in the charm $C=2$ and isospin $I=0$ sectors, where the doubly charmed tetraquark $T_{cc}^+(3875)$ should appear as a pole in the elastic $3 \to 3$...
The breaking of conformal and chiral symmetry determine the structure of the QCD vacuum and condition the emergent properties of light hadrons. We review recent efforts in studying these phenomena in the instanton liquid model of the QCD vacuum, a semiclassical picture abstracted from lattice QCD calculations. Chiral symmetry breaking is caused by the fermionic zero modes induced by the...
Nuclear structure effects on the energies of light (ordinary and muonic) atoms are the dominant source of uncertainty in the determination of the nuclear charge radii and other properties of light nuclei [1], [2]. The most important of these effects are the two-photon exchange (TPE) contributions. The present method of choice for studying them is ab initio theoretical calculations. In this...
We examine a pattern of dynamical chiral symmetry breaking making use of the vacuum energy density as a function of the quark condensate. We compute the vacuum energy density and the quark condensate in the interacting instanton liquid model (IILM) with three-flavor quarks. These computations are performed by using a numerical simulation of the canonical IILM, i.e., the number of instantons...
We study systems of two and three mesons composed of pions and kaons at maximal isospin using the E250 CLS ensemble with physical quark masses. Using the stochastic LapH method, we determine the energy spectrum of these systems including many levels in different momentum frames. Using the two- and three-body finite-volume formalism, we constrain the two and three-meson K matrix, including not...
Charge, magnetic and Zemach radii of light nuclei characterize the distribution of electromagnetic charge inside the corresponding nuclei and are a perfect tool to test modern high-precision nuclear forces. Experimentally, these radii can be extracted from electron scattering and the laser spectroscopy of normal and muonic atoms with precision often reaching sub-percent level. Theoretical...
We present a combined analysis of the electromagnetic form factors of the nucleon in the space- and time-like regions using dispersion theory. Our framework provides a consistent description of the experimental data over the full range of momentum transfer, in line with the constraints from analyticity and unitarity. The statistical uncertainties of the extracted form factors are estimated...
The polarizabilities of a composite system such as the proton are elementary structure constants. They describe it’s response to an external electromagnetic (EM) field and quantify the deformation of the charge and magnetization distributions inside the proton caused by the electric or magnetic field, respectively. When studied through the virtual Compton scattering process, the virtuality of...
I shall discuss the past, present and future of this remarkable theory.
I review some developments in chiral dynamics and pose some questions that remain to be answered.
Robustly simulating the nature and dynamics of non-equilibrium matter in extreme conditions of energy and density lies beyond the capabilities of classical computation alone. Toward realizing Feynman’s vision, the remarkable advances in quantum information science and technology during the last thirty years continue to profoundly change how we understand and explore fundamental quantum...
I will review the status of the dispersive approach to the two hadronic contributions (vacuum polarization and light-by-light) to the Muon g-2 and give an update on the current puzzles concerning the HVP.
The anomalous magnetic moment of the muon, also called the muon $g-2$, is a sensitive probe of the Standard Model. Any evidence for a non-zero deficit between experimental measurement and theoretical prediction would be ascribed to contributions from physics beyond the SM. While the latest experimental average displays a tension of 5.1$\sigma$ with the SM estimate as published in a White Paper...
In this talk, I review recent results on hadron interactions in lattice QCD, mainly those obtained by the HAL QCD method. In particular, I consider two hadron systems including strange, charm and bottom quarks such as $H$ dibaryon, $\Omega\Omega$, $\Omega_{ccc}\Omega_{ccc}$, $N\phi$, $NJ/\psi$, and tetra quark states $T_{cc}$ and $T_{bb}$. I emphasize the importance of the two-pion exchange...
Lattice QCD calculations of baryon-baryon scattering will be reviewed. In the last few years, there has been a new generation of calculations with increased focus on controlling systematic uncertainties. I will discuss the challenges and recent developments in these calculations.
This talk discusses recent applications of nuclear lattice simulations using chiral effective field theory. Some of the topics to be discussed are accelerated perturbation theory using wavefunction matching, seeing and measuring nucleonic correlations with the pinhole algorithm, intrinsic shapes, nuclear clustering, thermodynamics, and superfluidity.
In this talk, I will discuss chiral perturbation theory with axions, including the axion potential, axion mass, axionic couplings to photons and nucleons, and so on.
Next-generation neutrinoless double-beta decay (0vbb) experiments aim to discover lepton number violation in order to shed light on the nature of neutrino masses. A non-zero signal would have profound implications by demonstrating the existence of elementary Majorana particles and possibly pointing towards a solution of matter-antimatter asymmetry in the universe. However, the interpretation...
The issue of proper definition of spatial densities through matrix elements of local operators has attracted much attention in the last few years. In this talk, the novel definition of gravitational local spatial densities of hadrons using sharply localised wave packets will be discussed. We will show how the traditional densities in the Breit frame appear and how they differ from densities in...
The NA62 experiment at CERN collected the world's largest dataset of charged kaon decays in 2016--2018. In this talk, we report a new preliminary result of the $\pi^0 \rightarrow e^+ e^-$ branching fraction measurement at NA62. The result is based on a sample of signal decay candidates collected using a dedicated scaled-down di-electron trigger. Other recent NA62 results with analyses of rare...
We study dark matter, assumed to be composed by weak interacting massive particles (WIMPs), scattering off ${}^2$H and ${}^4$He nuclei. In order to parameterize the WIMP-nucleon interaction the chiral effective field theory approach is used. Considering only interactions invariant under parity, charge conjugation and time reversal, we examine five interaction types: scalar, pseudoscalar,...
The transition-density formalism is highly efficient for interactions with perturbative probes in few-nucleon systems. One- and two-body transition densities that encode the nuclear structure of the target are evaluated once per nucleus and stored. They are then convoluted with an interaction kernel to produce observables. The same densities can be used with different kernels. This method...
$\mu \to e$ conversion in nuclei gives one of the leading limits on BSM lepton-flavor violating (LFV) processes. Upcoming measurements call for a more consistent theoretical description of $\mu \to e$ conversion. This can be done model independently using an effective field theory framework in terms of effective BSM operators, which however crucially depends on hadronic and nuclear matrix...
In this talk, we provide compact analytic expressions for the one- and two-loop pion-pion partial-wave ChPT amplitudes for $J=0,\,1,\, 2$. We use these results to analyze lattice-QCD data of the ππ → ππ P wave obtained at unphysical-high pion masses using the inverse-amplitude method at next-to-leading order and next-to-next-to-leading order. We then extrapolate to the physical pion mass and...
The neutrinoless double beta decay $0\nu\beta\beta$ is of fundamental importance for particle physics, nuclear physics, and cosmology. The amplitude for the $0\nu\beta\beta$ decay of the two-neutron system $nn\rightarrow ppe^-e^-$ is a key building block to calculate the $0\nu\beta\beta$ decay in nuclei employed in large-scale experimental searches. Assuming that $0\nu\beta\beta$ decay is...
Pion-Photoproduction and other elastic processes are analyzed in chiral effective field theory around threshold. We extend the work by Lenkewitz et. al. to include the chiral SMS potential with uncertainty estimation based on cutoff variation. In particular we consider as targets ${}^3\mathrm{He},\;{}^4\mathrm{He} $ and ${}^6\mathrm{Li}$ which enter through their probability density amplitudes...
In this talk, we will discuss a recent study on the electromagnetic form factor of nucleons from our group. The SU(3) chiral effective field theory is applied to calculate the potential of nucleon anti-nucleon scatterings up to the next-to-leading order. The potentials are then input into the Lippmann-Schwinger equation, and the scattering amplitudes are solved. These potentials are input as...
Neutrino oscillation measurements hint at non-zero neutrino masses, and the addition of gauge singlet right-handed neutrinos to the SM field content conveniently provides masses to the active neutrinos. A byproduct of this mechanism is the possible Majorana nature of neutrinos, which leads to lepton number violating effects, such as neutrinoless double beta decay. The standard study of these...
The R value, defined as the ratio of inclusive hadronic cross section over dimu cross-section from electron-positron annihilation, is an important quantity that contributes to the SM prediction of the muon anomalous magnetic moment, and in the determination of the QED running coupling constant evaluated at the Z pole. At BESIII, the R value is measured with a total of 14 data points with the...
The electromagnetic form factors of the nucleon have been widely used for exhibiting how the charge and magnetization distributions are spatially distributed inside a nucleon in the Breit frame. Similarly, the Energy-Momentum-Tensor form factors (i.e. gravitational form factors, GFFs) characterize the mechanical properties, such as the three-dimensional distributions of mass, angular momentum,...
Parity-violating and time-reversal-violating (PVTV) nuclear interactions govern electric dipole moments of nuclei and play an important role in searches for beyond-Standard-Model physics. Recently, PVTV two- and three-nucleon potentials have been worked out to next-to-next-to-leading order in the chiral effective field theory (EFT) expansion based on pions and nucleons as the only explicit...
I will present the work on short-distance contributions to the hadronic light-by-light part of the muon g-2 as in the Standard Model. Work done since the previous chiral dynamics is working out how to calculate in principle the higher order corrections to the Melnikov-Vainshtein result, published in JHEP 02 (2023) 167 [2211.17183 [hep-ph]]. In addition I will preesent the sofar unpublished...
In this talk I will discuss the dependence of the primordial nuclear abundances as a function of fundamental physical constants like the electromagnetic fine-structure constant $\alpha$ and the Higgs VEV $v$. We updated the leading nuclear reaction rates and used more recent results for the electromagnetic and strong contribution to the neutron-proton mass difference. For the...
The Bernabéu-Tarrach sum rule, which could potentially provide an additional data-driven constraint on nucleon electric polarizabilities, will be discussed. Moreover, its convergence implies a sum rule for the unknown subtraction function in the two-photon exchange contribution to the Lamb shift. The verification of these sum rules using covariant chiral perturbation theory and the naïve...
A dispersive implementation of the $\pi\eta/K\bar{K}$ scattering to $(g-2)_\mu$ requires the knowledge of the double-virtual $S$-wave $\gamma^*\gamma^*\to\pi\eta/ K\bar{K}_{I=1}$ amplitudes. To obtain these amplitudes we used a modified coupled-channel Muskhelishvili–Omnes formalism, with the input from the left-hand cuts and the hadronic Omnes function. The latter were obtained using a...
The world’s largest sample of J/psi events accumulated at the BESIII detector offers a unique opportunity to investigate eta and eta' physics via two body J/psi radiative or hadronic decays. In recent years the BESIII experiment has made significant progresses in eta/eta' decays. A selection of recent highlights in light meson spectroscopy at BESIII are reviewed in this report, including...
I will describe our recent effort on the precise calculation of the radiative correction to semileptonic kaon decays that leads to an improved determination of the CKM matrix element Vus and further sharpens the so-called "Cabibbo angle anomaly".
Laser spectroscopy of muonic atoms has been recently used to probe the low-energy properties of the proton and light nuclei with unprecedented precision [1]. In the future, measurements of the Lamb shift in muonic hydrogen and helium isotopes are supposed to improve by up to a factor 5. Furthermore, there is an ongoing effort to perform a first-time measurement of the ground-state hyperfine...
Through the calculation of nucleon matrix elements in the off-forward limit, a wealth of information on the structure of the nucleon can be accessed using lattice QCD. This includes the determination of the electromagnetic form factors, the axial form factors and moments of generalised parton distribution functions, such as the gravitational form factors. Significant progress has been made in...
High precision data in the Low-Q2 regime is crucial for the study of effective theories such as chiral perturbation theory, which collectively remain the best treatment of QCD in the non-perturbative regime. Measurements of the nucleon spin structure functions and their moments provide a very useful means to directly test the predictions of effective theories. The Jefferson Lab community has...
