First proton directed-flow measurement from Xe+Cs at 3.8 AGeV
New NICA data match JAM and extend equation-of-state tests to a new system.
· “Analysis Note: Directed flow v₁ of protons in the Xe+Cs(I) collisions at 3.8 AGeV”
nucl-ex
Nuclear Experiment
Nuclear Experiment Results from experimental nuclear physics including the areas of fundamental interactions, measurements at low- and medium-energy, as well as relativistic heavy-ion collisions. Does not include: detectors and instrumentation nor analysis methods to conduct experiments; descriptions of experimental programs (present or future); comments on published results
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A 21-sigma lead anomaly meets an 11-target electron scan
The answer decides whether the 21-sigma lead result is a new effect or an artifact.
· “Nuclear Dependence of Beam Normal Single Spin Asymmetry in Elastic Scattering from Nuclei”
Archived ALEPH data yield the sharpest full-range energy correlator yet
Charged tracks from 1994 Z decays map QCD from tiny to back-to-back angles with finer bins than any LEP result.
First fully corrected energy correlator spans collinear to back-to-back QCD
Using archived ALEPH data, the strong force now has a single measurement reaching the back-to-back limit.
Beta decay constrains r-process neutron-capture rates
Gamma-cascade measurements narrow theoretical rate uncertainties from a factor of 10 to about a factor of 2-3.
· “The beta-Oslo method: experimentally constrained (n,γ) reaction rates relevant to the r-process”
First polarization asymmetries measured for pion-pair photoproduction
Eight beam, target, and beam-target observables from 1.51-2.04 GeV will sharpen baryon-resonance fits.
Uranium-238 'pear' shape would flip a flow ratio
Triangular-flow ratios between uranium and gold should reverse in the most central collisions if the octupole deformation is real.
· “Imprints of octupole collectivity in uranium-238 on relativistic heavy-ion flow observables”
New K radii: isospin breaking in A=38 is zero within error
Precise isotope-shift calculations benchmark the corrections needed to extract Vud from superallowed beta decays.
73,75Br proton removal yields equal cross sections into 72,74Se
Matching cross sections into 72Se and 74Se suggest the same proton orbitals drive both reactions.
· “Proton removal from ^(73,75)Br to ^(72,74)Se at intermediate energies”
D_s decay exposes a0(980) as a meson molecule
A single fitted strength reproduces the BESIII data once the two decay paths interfere destructively.
· “Theoretical interpretation of the D^+_s to π^+ π⁰ η decay and the nature of a₀(980)”
Chiral magnetic fields become a measurable charge dipole
MHD simulations show the chiral magnetic effect survives expansion and appears in flow observables.
· “Magnetic fields in heavy ion collisions: flow and charge transport”
K* mesons fade in high-multiplicity pp collisions at 7σ
First clear K*/K_S0 suppression in a small system, concentrated below 2 GeV/c.
· “Multiplicity dependence of K^*(892)^(pm) production in pp collisions at sqrt{s} = 13 TeV”
Yttrium-doped BaF2 crystal times particles to 82 ps
Large 200-mm scintillator keeps its fast component while suppressing the slow one, promising sub-100 ps detectors.
· “Scintillation and Timing Performance of a 3at% Yttrium-Doped Barium Fluoride Crystal”
Level density of 128Te extracted without model-based normalization
Photonuclear data fix the scale and slope, so the result is independent of constant-temperature or Fermi-gas assumptions.
· “Nuclear level density of {}¹²⁸Te from (p,p'γ) scattering and complementary photonuclear data”
A density-only functional reproduces deformed 20Ne
Trained on random potentials, it matches Kohn-Sham deformation and energies without single-particle orbitals.
Knockout reactions reveal what exotic nuclei are made of
Distorted-wave theory plus CDCCIA maps measured cross sections to orbits, pairs, and alpha clusters.
· “Reaction mechanism of quasi-free knockout processes in exotic RI beam era”
Backward gamma-ray transport beats forward by 10⁴×
Goupil simulates environmental radiation from a huge source to a tiny detector while keeping photopeaks intact.
· “Goupil: A Monte Carlo engine for the backward transport of low-energy gamma-rays”
One number links nuclear binding energy to charge radius
A measured mirror partner's mass and radius predict the proton-rich side's size and binding.
· “Robust correlation between binding energies and charge radii of mirror nuclei”
Late mean-field potential, not squeeze-out, sets negative v2
UrQMD shows that after the last collision the potential still shapes v2; the final value reflects breakup geometry.
Mercury's hyperfine anomaly measured: rule constant near zero
Fifty years untested; the new fit puts the constant near zero, sharpening mercury clocks and EDM searches.
· “The hyperfine anomaly in mercury and test of the Moskowitz-Lombardi rule”
GERDA sees no neutrinoless double-beta decay in 82.4 kg·yr
Half-life limit tops 10^26 years, making GERDA the first search to reach that sensitivity.
Electron shake in 125I decay is 2.5 times predicted
High-resolution spectra also pin the 35.5-keV transition's penetration parameter at -1.2(6), a small negative anomaly.
· “High-resolution conversion electron spectroscopy of the 125I electron-capture decay”
One momentum observable now fixes the quark-gluon plasma's temperature
Charged-particle momentum alone gives 2.58 trillion kelvin, plus entropy density and sound speed that match lattice QCD.
· “Thermodynamics of hot strong-interaction matter from ultrarelativistic nuclear collisions”
Omega pairs should show a telltale correlation peak at low momentum
p-Omega pairs should dip below unity at q=20-40 MeV/c, the predicted signature of a bound dibaryon
· “Probing ΩΩ and pΩ dibaryons with femtoscopic correlations in relativistic heavy-ion collisions”
Particle yields reveal pre-collision energy via 2/3 law
Under this attractor relation, particle counts become a direct probe of the plasma before it thermalizes.
Strange hadrons rise faster than charged particles with multiplicity
13 TeV data show the rise steepens with strangeness content and tracks mid-rapidity density, not collision energy.
Forbidden atomic states multiply 159Dy's neutrino-mass signal tenfold
For 159Dy, this makes an ultra-low Q-value electron-capture candidate viable for neutrino-mass searches.
· “Contribution of Subthreshold States to the Residual Energy Distribution of ¹⁵⁹Dy”
Tritium from TiD2 exceeds predictions by up to 5.1×
The excess appears only under fast neutrons, hinting at electron-screening-enhanced fusion in the solid state.
· “Enhanced Tritium Production in Irradiated TiD2 from Collisional Fusion in the Solid-State”
VUV laser maps four thorium sites in a nuclear-clock crystal
Site-selective field gradients and lifetimes provide the material data needed to build solid-state nuclear clocks.
Neutron emission grows as nuclei move away from 208Pb
At fixed N=126, proton number drives total neutron multiplicity in pre-actinides.
· “Cross talk between experimental data and simple validation of shell closure in pre-actinides”
Neutron-pickup ratios trace tensor-driven high-momentum states
Zero-degree proton-induced pickup on oxygen-16 matches tensor-including theory, opening the path to exotic nuclei.
40 kg of 60%-enriched uranium can become a kiloton bomb
Roughly a tenth of a reported 408-kg stockpile could be smuggled in a standard cargo container.
Rho and omega mesons lose ~10% of mass inside nuclei
Low-mass excesses at 8.5-13.4 sigma in dielectron spectra point to density-dependent vector-meson mass shifts.
· “Velocity dependence of the mass modifications of rho and ω mesons in 12 GeV p+A reactions”
Four pulse integrals plus a likelihood fit cut 3D position error to 0.02 mm
Jointly fitting integral-based pulse parameters removes cross-dimensional bias that single-axis amplitude methods cannot.
Electron-positron energy correlator turns non-perturbative at 2.3 GeV
A global fit to e+e− data from 29 to 91 GeV finds the quark-jet scale is 2.3 GeV, below the gluon-jet scale of 3.8 GeV.
Neural net labels ion spectra 9 percent sharper than manual analysis
Trained on a fraction of hand-labeled events, it resolves charge state and atomic number in hours, not months.
Two experiments aim to show neutrinos are their own antiparticles
Canadian-built SNO+ and nEXO could probe the inverted neutrino mass hierarchy within a decade.
· “Canadian Contributions to the Search for Neutrinoless Double Beta Decay”
17C pins the N=16 shell gap at 5.08 MeV
First measurement of the unbound 0d3/2 neutron strength in 17C places the gap 1.3 MeV above the shell-model prediction.
· “Unbound neutron ν0d_(3/2) strength in ¹⁷C and the N=16 shell gap”
57 new gamma rays map 202Po to spin 27ℏ
A 9.0 keV missing transition and three M1 cascades sharpen the N=118 shell-model test.
· “Competition between the neutron-proton pair break-ups delineating the level structure of 202Po”
First Compton cross-section data from 6.5–11 GeV match NLO QED
The first data on QED radiative corrections to Compton scattering at 6.5–11 GeV, at 3.4% precision.
· “Measurement of the Total Compton Scattering Cross Section between 6.5 and 11 GeV”
Two-stage time stretching gives 63 ps timing with a 100 MHz clock
A low-cost FPGA prototype keeps 60–100 ps resolution and under 300 ns dead time.
· “A two-stage time-stretching TDC with discrete components”
Hypernuclear peak at 13.8 MeV is interference of two spin components
The broad 3.8 MeV bump is a continuum effect rather than a genuine resonance.
· “Continuum Lambda spectra for a 6Li_Lambda hypernucleus in the 6Li(K-, pi-) reaction”
New data rule out 76Cu's 1.27-second decay
Two decay curves cap any long-lived component at 2–5%, leaving both states near 0.65 s.
Four gauge-invariant pieces tame nuclear radiative corrections
Rewriting the hadronic tensor keeps closure and density approximations gauge-invariant, cutting a known percent-level error.
Spin-orbit coupling can create directed flow in pp
Forward two-particle correlations would expose the proton's double-helicity PDFs.
· “Directed flow from parton spin-orbit coupling in pp and pA collisions”
Two 24Mg states are the strongest core+α condensate candidates yet
New real-time evolution calculation gives them large monopole strength and tiny alpha widths, making them observable.
· “The candidates of 2α condensate around the 16O nucleus studied by the real-time evolution method”
Rydberg atom glow reveals electron beam position to 8 microns
Fluorescence of laser-prepared rubidium atoms reconstructs beam position, width, and current from one camera sweep.
· “Electron beam characterization via fluorescence imaging of Rydberg states in atomic vapor”
Nucleon size shifts deformation extraction by up to 65%
Point-nucleon analyses bias some beta-2 probes but leave scaled v2 and rho2 stable; O+O delta-pT measures nucleon size.
· “Disentangling effects of nucleon size and nucleus structure in relativistic heavy-ion collisions”
No enhanced weak asymmetry in the proton-to-Delta transition
The parity-violating coupling dΔ comes out near zero, unlike the large value inferred from hyperon decays.
· “Measurement of the Parity-Violating Asymmetry in the N to Delta Transition at Low Q²”
Proton decay in two or three channels could identify the BSM operator
Channel ratios, not a single event, would point to the underlying operator and guide grand-unified-theory searches.
· “Baryon Number Violation: From Nuclear Matrix Elements to BSM Physics”
MORA polarizes trapped ions past 55 percent
First beta-recoil coincidences clear a path to a time-reversal-invariance test in nuclear beta decay.
· “Performance of the MORA Apparatus for Testing Time-Reversal Invariance in Nuclear Beta Decay”
Nuclear matter shrinks baryons' electroweak form factors
Model predicts up to 30% axial suppression at saturation density, cutting neutrino cross sections.
· “Electroweak form factors of baryons in dense nuclear matter”
Two-proton decay angles confirm proton-proton force strength
New data on 48Ni and 45Fe match small-angle emission and constrain shell structure, but half-lives still disagree.
New 84Mo mass rules out ZrNb cycle in X-ray bursts
A measured alpha-separation energy of 1.434(83) MeV closes the predicted cycle and trims A=80-90 ash uncertainties.
Relativistic nuclear force matches standard accuracy at lower order
Covariant chiral force reproduces NN scattering to 200 MeV with fast convergence, aiding ab initio nuclear theory.
· “Relativistic chiral nuclear forces: status and prospects”
Photon data can confirm proton-neutron dominance in nuclei
Two cross-section ratios also test whether a photon's hard hit cleanly separates from nuclear structure.
· “Observing short-range correlations in nuclei through rho⁰ photo-production”
One code now automates NLO QCD for proton-nucleus collisions
Extension of MadGraph5_aMC@NLO validates on pPb W/Z and pion-tungsten Drell-Yan, with automatic uncertainties.
· “Automated NLO calculations for asymmetric hadron-hadron collisions in MadGraph5_aMC@NLO”
Ground and isomeric nuclei end up in different ion charge states
Fission-fragment thermalization in helium shows yield ratios varying between isotopes and nuclear isomers, beyond known isotope effects.
· “Anomalous nuclear effects on ion charge state distribution in helium gas”
Antiprotonic calcium x-rays could reveal the isovector force term
One-electronvolt shifts would fix the isovector parameter and aid neutron-antineutron oscillation searches.
Gallium solar-neutrino cross sections: 8B and hep up ~10%
Updated theory raises the gallium detectors' high-energy response and halves the old uncertainty.
· “The Gallium Solar Neutrino Capture Cross Section Revisited”
187Ta isomer's decays finally seen: 136-second life
The decay paths reveal a K ≥ 35/2 prolate isomer, a test for the predicted shape transition near A = 190.
· “Direct observation of β and γ decay from a high-spin long-lived isomer in ¹⁸⁷Ta”
6H ground state pinned at 2.3 MeV by electron scattering
Triple-coincidence missing-mass data favor the low-energy measurements and challenge multi-neutron interaction models.
· “Measurement of rm ⁶H ground state energy in an electron scattering experiment at MAMI-A1”
Sustained software funding is vital for nuclear physics
A community workshop argues short-term grants waste the payoff from supercomputers, data, and skilled software staff.
· “White Paper on Software Infrastructure for Advanced Nuclear Physics Computing”
QCD sum rules close the mirror-nucleus energy gap
A charge-symmetry-breaking force from QCD constants reproduces the Okamoto-Nolen-Schiffer anomaly without fitting.
One fermionic hierarchy yields all nuclear models
Ab initio, density-functional, and beyond-mean-field nuclear methods become controlled truncations of one equation-of-motion hierarchy.
New best limits on rare tri-nucleon decays: 1.83e26 yr
Full Majorana Demonstrator data push three-nucleon decay lifetimes beyond 10^26 years.
· “Rare multi-nucleon decays with the full data sets of the Majorana Demonstrator”
Lifetime measurement identifies mixed-symmetry state of 132Te
The measured 0.92 ps lifetime gives B(M1) = 0.18(2), settling the identity of the second 2+ state.
· “Isolated one-phonon mixed-symmetry 2+ state of the radioactive neutron-rich nuclide 132Te”
Elliptic anisotropy stays positive up to 100 GeV in Pb+Pb collisions
New ATLAS data link the shape of the quark-gluon plasma to jet energy loss up to 100 GeV.
ALICE J/psi photoproduction data favor gluon saturation in nuclei
These probes reach x ~ 10^-6, and Run 3/4 will cut the nuclear suppression uncertainty to about 4%.
· “Recent ALICE results relevant for PDFs at low and high-x, saturation”
149Tm is first proton-unbound thulium isotope
Weighing 149Tm, 150Tm and 149Er fixes the Z=69 drip-line at N=80 and tests mass models.
Dileptons track the QGP temperature
Selection on dilepton mass and momentum maps QGP temperatures from late times to under 1 fm/c.
· “Effective temperatures of the QGP from thermal photon and dilepton production”
Strangeness data overturn the old proton-collision picture
Review says multiplicity-dependent strange-baryon excesses leave no viable model without final-state interactions.
· “Soft QCD Physics at the LHC: highlights and opportunities”
One boson coupling controls 68As beta-decay predictions
Mapped IBM reproduces half-life trends across Ge, As, Zr, Mo; higher-order operator terms shift results only 5–10%.
Molecule picture survives X(3872) production test
Prompt rates match when the cutoff is the force range, not the tiny binding momentum — the old 1000x gap closes.
· “Production of exotic hadrons in pp and nuclear collisions”
New study extends 37K level scheme to a 13/2− state
High-momentum-loss reactions reveal negative-parity states and mirror-energy differences vs 37Ar.
· “In-beam γ-ray spectroscopy of negative-parity states of ³⁷K populated in dissipative reactions”
124Xe double electron capture half-life measured at 10^22 yr
A 1.73 tonne-year run finds 549 signal events, sharpening the nuclear theory benchmark for electron capture decay.
· “Measurement of two-neutrino double electron capture half-life of ¹²⁴Xe with PandaX-4T”
First data-driven value for the nucleon D-term: -3.38
Dispersion relations set the nucleon's gluonic radius at 0.97 fm, wider than the proton charge radius.
· “Dispersive Determination of Nucleon Gravitational Form Factors”
Symmetry energy softens sharply near twice nuclear density
A tuned sigma-delta mixing term lets one model family match PREX-2, NICER, and GW170817 at the same time.
A single exponential captures jet energy correlator data at all angles
A TMD-inspired non-perturbative model plus medium broadening reproduces CMS, ALICE and pPb measurements.
· “Energy-Energy Correlator for jet production in pp and pA collisions”
20Ne's measured shape breaks the rotor model by 3σ
A new precise quadrupole-moment measurement points to missing alpha-cluster physics in today's nuclear theories.
