Ab initio calculation of the neutron-proton mass difference

Abstract

The existence and stability of atoms rely on the fact that neutrons are more massive than protons. The measured mass difference is only 0.14\% of the average of the two masses. A slightly smaller or larger value would have led to a dramatically different universe. Here, we show that this difference results from the competition between electromagnetic and mass isospin breaking effects. We performed lattice quantum-chromodynamics and quantum-electrodynamics computations with four nondegenerate Wilson fermion flavors and computed the neutron-proton mass-splitting with an accuracy of $300$ kilo-electron volts, which is greater than $0$ by $5$ standard deviations. We also determine the splittings in the $\Sigma$, $\Xi$, $D$ and ${\Xi }_{cc}$ isospin multiplets, exceeding in some cases the precision of experimental measurements.

57 pages, 15 figures, 6 tables, revised version

References in corpus (14)

• Ab-initio Determination of Light Hadron Masses
• High-precision scale setting in lattice QCD
• Accelerating Dynamical Fermion Computations using the Rational Hybrid Monte Carlo (RHMC) Algorithm with Multiple Pseudofermion Fields
• Light hadrons from lattice QCD with light (u,d), strange and charm dynamical quarks
• First results from 2+1 dynamical quark flavors on an anisotropic lattice: light-hadron spectroscopy and setting the strange-quark mass
• QED in finite volume and finite size scaling effect on electromagnetic properties of hadrons
• Nucleon sigma term and strange quark content from lattice QCD with exact chiral symmetry
• Electromagnetic mass splittings of the low lying hadrons and quark masses from 2+1 flavor lattice QCD+QED
• Determination of light quark masses from the electromagnetic splitting of pseudoscalar meson masses computed with two flavors of domain wall fermions
• Rationale for UV-filtered clover fermions
• The Electromagnetic Self-Energy Contribution to M_p - M_n and the Isovector Nucleon Magnetic Polarizability
• Accelerating Staggered Fermion Dynamics with the Rational Hybrid Monte Carlo (RHMC) Algorithm
• Scaling study of dynamical smeared-link clover fermions
• Electromagnetic Corrections in Partially Quenched Chiral Perturbation Theory

Cited by in corpus (49)

• Baryons as relativistic three-quark bound states
• Simulation of QCD with N_f=2+1 flavors of non-perturbatively improved Wilson fermions
• Charmed bottom baryon spectroscopy from lattice QCD
• Baryons with two heavy quarks: Masses, production, decays, and detection
• Finite-Volume QED Corrections to Decay Amplitudes in Lattice QCD
• An ${\epsilon }^{\prime }$ improvement from right-handed currents
• Kaon electromagnetic form factors in dispersion theory
• First-principles calculation of electroweak box diagrams from lattice QCD
• Preparation of the SU(3) Lattice Yang-Mills Vacuum with Variational Quantum Methods
• P- and T-Violating Lagrangians in Chiral Effective Field Theory and Nuclear Electric Dipole Moments
• Lattice QCD for Cosmology
• Isospin breaking corrections to meson masses and the hadronic vacuum polarization: a comparative study
• Isospin splittings in baryons with two heavy quarks
• Long-distance Contributions to Neutrinoless Double Beta Decay ${\pi }^{-}\to {\pi }^{+}ee$
• Static $\bar{Q}Q$ pair free energy and screening masses from correlators of Polyakov loops: continuum extrapolated lattice results at the QCD physical point
• The path from lattice QCD to the short-distance contribution to $0\nu \beta \beta$ decay with a light Majorana neutrino
• Effects of long-range forces on the D-term and the energy-momentum structure
• The anomalous magnetic moment of the muon: status of Lattice QCD calculations
• On the role of isospin violation in the pion-nucleon $\sigma$-term
• Advances in machine-learning-based sampling motivated by lattice quantum chromodynamics
• Chiral Corrections to Nucleon Two- and Three-Point Correlation Functions
• Uncertainty Quantification in Lattice QCD Calculations for Nuclear Physics
• Phenomenology of unusual top partners in composite Higgs models
• Next-to-leading order scalar contributions to $\mu \to e$ conversion
• Kenneth Wilson and lattice QCD
• Future tests of parton distributions
• Finite-volume corrections to the leading-order hadronic contribution to $g_{\mu }-2$
• Permanent Electric Dipole Moments of Single-, Two-, and Three-Nucleon Systems
• Chiral Effective Theory Methods and their Application to the Structure of Hadrons from Lattice QCD
• Electromagnetic corrections to the leptonic decay rates of charged pseudoscalar mesons: lattice results
• Neutrinos, supernovae, and the origin of the heavy elements
• Charge Symmetry Violation in the Electromagnetic Form Factors of the Proton
• The running coupling of 8 flavors and 3 colors
• The muon abundance in the primordial Universe
• Lattice QCD and Baryon-Baryon Interactions
• Nucleon tomography. What can we do better today than Rutherford 100 years ago?
• Inclusion of isospin breaking effects in lattice simulations
• Electromagnetic Corrections to Meson Masses and the HVP
• Isospin breaking corrections to the HVP at the physical point
• Isospin Breaking in Lattice QCD Computations of Decay Amplitudes
• Review on Hadron Spectroscopy
• Dynamical QCD+QED simulation with staggered quarks
• Towards the large volume limit - A method for lattice QCD + QED simulations
• Rotated twisted-mass: a convenient regularization scheme for isospin breaking QCD and QED lattice calculations
• Lattice inputs to Flavor Physics
• Isospin breaking from diquark clustering
• Formal Developments for Lattice QCD with Applications to Hadronic Systems
• High precision applications of lattice gauge theories in the quest for new physics
• Uncovering an Axion Mechanism with the EDM Portfolio