A5046037456- Nuclear physics research studies
- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- Neutrino Physics Research
- Quantum, superfluid, helium dynamics
- Atomic and Subatomic Physics Research
- Solar and Space Plasma Dynamics
- Advanced Chemical Physics Studies
- Graphene research and applications
- Nanopore and Nanochannel Transport Studies
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Atomic and Molecular Physics
- Dark Matter and Cosmic Phenomena
- Radioactive Decay and Measurement Techniques
- Advanced Thermodynamics and Statistical Mechanics
- Quantum and electron transport phenomena
- Black Holes and Theoretical Physics
- Solar Radiation and Photovoltaics
- Physics of Superconductivity and Magnetism
- Advanced Materials and Mechanics
- Nuclear Physics and Applications
- Atmospheric Ozone and Climate
- COVID-19 epidemiological studies
- Plasma Diagnostics and Applications
Hebrew College
2015-2024
Hebrew University of Jerusalem
2013-2023
Czech Academy of Sciences, Institute of Physics
2019
University of Washington
2008-2010
Seattle University
2009
The available data on nuclear fusion cross sections important to energy generation in the Sun and other hydrogen-burning stars solar neutrino production are summarized critically evaluated. Recommended values uncertainties provided for key sections, a recommended spectrum is given $^{8}\mathrm{B}$ neutrinos. Opportunities further increasing precision of rates also discussed, including new facilities, experimental techniques, improvements theory. This review, which summarizes conclusions...
The chiral low-energy constants ${c}_{D}$ and ${c}_{E}$ are constrained by means of accurate ab initio calculations the $A=3$ binding energies and, for first time, triton $\ensuremath{\beta}$ decay. We demonstrate that these observables allow a robust determination two undetermined constants, result surprising fact depends weakly on short-range correlations in wave functions. These two- plus three-nucleon interactions, originating effective field theory properties $A=2$ system present...
We show that chiral effective field theory (EFT) two-body currents provide important contributions to the quenching of low-momentum-transfer Gamow-Teller transitions, and use EFT predict momentum-transfer dependence is probed in neutrinoless double-beta decay. then calculate for first time decay operator based on study nuclear matrix elements at successive orders. The from are significant should be included all calculations.
We perform state-of-the-art large-scale shell-model calculations of the structure factors for elastic spin-dependent WIMP scattering off 129,131Xe, 127I, 73Ge, 19F, 23Na, 27Al, and 29Si. This comprehensive survey covers non-zero-spin nuclei relevant to direct dark matter detection. include a pedagogical presentation formalism necessary describe inelastic WIMP-nucleus scattering. The valence spaces nuclear interactions employed have been previously used in these mass regions yield good...
Chiral effective field theory (EFT) provides a systematic expansion for the coupling of WIMPs to nucleons at momentum transfers relevant direct cold dark matter detection. We derive currents spin-dependent WIMP scattering off nuclei one-body level and include leading long-range two-body currents, which are predicted in chiral EFT. As an application, we calculate structure factor 129,131Xe nuclei, using nuclear interactions that have been developed study double-beta decays this region....
We show how nuclear effective field theory (EFT) and ab initio nuclear-structure methods can turn input from lattice quantum chromodynamics (LQCD) into predictions for the properties of nuclei. argue that pionless EFT is appropriate to describe light nuclei obtained in LQCD simulations carried out at pion masses heavier than physical mass. solve using effective-interaction hyperspherical harmonics auxiliary-field diffusion Monte Carlo methods. Fitting three leading-order parameters deuteron,...
The anomalous exponents governing the long wavelength behavior of flat phase physical crystalline membranes are calculated within a self-consistent screening approximation (SCSA) applied to second order expansion in 1/d_C (d_C is co-dimension), extending seminal work Le Doussal and Radzihovsky [Phys. Rev. Lett. 69, 1209 (1992)]. In particular, bending rigidity found harden algebraically limit with an exponent eta=0.789..., which used extract elasticity softening eta_u=0.422..., roughness...
We optimize chiral interactions at next-to-next-to leading order to observables in two- and three-nucleon systems compute Gamow-Teller transitions $^{14}\mathrm{C}$ $^{22,24}\mathrm{O}$ using consistent two-body currents. spectra of the daughter nuclei $^{14}\mathrm{N}$ $^{22,24}\mathrm{F}$ via an isospin-breaking coupled-cluster technique, with several predictions. The currents reduce Ikeda sum rule, corresponding a quenching factor ${q}^{2}\ensuremath{\approx}0.84--0.92$ axial-vector...
The 4He total photoabsorption cross section is calculated with the realistic nucleon-nucleon potential Argonne V18 and three-nucleon force (3NF) Urbana IX. Final state interaction included rigorously via Lorentz integral transform method. A rather pronounced giant resonance peak sections of 3.0 (3.2) mb obtained (without) 3NF. Above 50 MeV strong 3NF effects, up to 35%, are present. Good agreement experiment found close threshold. comparison in region inconclusive, since data do not show a...
An effective field theory is used to describe light nuclei, calculated from quantum chromodynamics on a lattice at unphysically large pion masses. The calibrated leading order two available data sets two- and three-body nuclei for At those masses we predict the quartet doublet neutron-deuteron scattering lengths, alpha-particle binding energy. For $m_\pi=510~$MeV obtain, respectively, $^4a_{\rm nD}=2.3\pm 1.3~$fm, $^2a_{\rm nD}=2.2\pm 2.1~$fm, $B_{\alpha}^{}=35\pm 22~$MeV, while...
Abstract Concomitantly with rolling out its rapid COVID-19 vaccine program, Israel is experiencing third, and so far largest, surge in morbidity. We aimed to estimate whether the high coverage among individuals aged over 60 years old creates an observable change disease dynamics. Using observed simulated data, we suggest that shape of outbreak as measured by daily new moderate severe cases, particular patients 60, has changed because vaccination, bringing decline cases earlier than expected,...
Precision measurements of $\beta$-decay observables offer the possibility to search for deviations from Standard Model. A possible discovery such requires accompanying first-principles calculations. Here we compute nuclear structure corrections $^6$He which is central interest in several experimental efforts. We employ impulse approximation together with wave functions calculated using ab initio no-core shell model potentials based on chiral effective field theory. use these state-of-the-art...
We extend the virial equation of state to include $^{3}\mathrm{H}$ and $^{3}\mathrm{He}$ nuclei, predict significant mass-three fractions near neutrinosphere in supernovae. While alpha particles are often more abundant, we demonstrate that energy transfer cross sections for muon tau neutrinos at low densities dominated by breakup loosely-bound nuclei. The coefficients involving $A=3$ nuclei calculated directly from corresponding nucleon-$^{3}\mathrm{H}$ nucleon-$^{3}\mathrm{He}$ scattering...
Only one atom thick and not inclined to lattice defects, graphene represents the ultimate crystalline membrane. However, its structure reveals unique features found in other membranes, particular existence of ripples with wavelength $100--300\text{ }\text{\AA{}}$. Here, I trace origin this difference free electrons The deformation energy creates a coupling between charge fluctuations structure, resulting on membrane, correlated inhomogeneities. In mechanism reproduces experimental result for...
The calculation of line widths constitutes theoretical and computational challenges in the opacities hot dense plasmas. Opacity models use broadening approximations that are untested at stellar interior conditions. Moreover, calculations atomic spectra sun, indicate a large discrepancy K-shell between several codes OP. In this work, code STAR is used to study sensitivity solar line-broadening. Variations opacity profile, due an increase Stark resulting from discrepancies with OP, compared,...
ABSTRACT A new opacity model has been developed based on the Super-Transition-Array (STA) method for calculation of monochromatic opacities plasmas in local thermodynamic equilibrium. The atomic code, named STAR (STA-Revised), is described and used to calculate spectral a solar implementing recent AGSS09 composition. Calculations are carried out throughout radiative zone. relative contributions different chemical elements processes total Rosseland mean analyzed detail. Monochromatic...
The inelastic scattering of neutrino off $^{4}\mathrm{He}$ is calculated microscopically at energies typical for core-collapse supernova environment. calculation carried out with the Argonne V18 nucleon-nucleon potential and Urbana IX three-nucleon force. Full final state interaction included via Lorentz integral transform method. contribution axial meson exchange currents to cross sections taken into account from effective field theory nucleons pions order $\mathcal{O}({Q}^{3})$.
The weak form factors of the nucleon, including induced pseudoscalar factor and second class terms, are constrained using a microscopic calculation capture process He3(μ−,νμ)H3. is parameter free, yields rate 1499(16) Hz, in agreement with remarkable experimental measurement 1496(4) Hz. nuclear wave functions obtained EIHH method Argonne v18 nucleon–nucleon potential Urbana-IX three nucleon force. currents nuclei described HBχPT formalism. found to agree prediction. result compatible...
Graphene is a realization of an uncommon class materials---electronic crystalline membranes. We study the interplay between free electrons and two-dimensional crystal find that it induces substantial effect on elastic structure membrane. For hole-doped membrane, in particular, we predict spontaneous buckling. In addition, attenuation waves expected due to corrugations bulk modulus. These discoveries have considerable magnitude graphene, affecting both its mesoscopic electrical resistivity,...
We calculate the $\ensuremath{\beta}$ decay of tritium at next-to-leading order in pionless effective field theory. At this order, a low-energy parameter ${l}_{1,A}$ enters calculation that is also relevant for high-accuracy prediction solar proton-proton fusion rate. use half-life to determine and provide uncertainty estimates. show proper renormalization our analyzing residual cutoff dependence observables. find next-to-leading-order corrections contribute about $4%$ triton Gamow-Teller...
We present a microscopic calculation of the $^{6}\mathrm{He} \ensuremath{\beta}$-decay into ground state $^{6}\mathrm{Li}$. To this end, we use chiral perturbation theory at next-to-next-to-next-to-leading order to describe nuclear weak-currents. The wave functions are derived from $J$-matrix inverse scattering nucleon-nucleon potential (JISP), and Schr\"odinger equation is solved using hyperspherical-harmonics expansion. Our brings theoretical decay-rate within $3%$ measured one. This...
Within the Standard Model, weak interaction of quarks and leptons is characterized by certain symmetry properties, such as maximal breaking parity favored helicity. These are related to $V-A$ structure interaction. characteristics were discovered studying correlations in directions outgoing nuclear beta decays. days, correlation measurements decays intensively studied probe for signatures deviations from these symmetries, which an indication Beyond Model physics. We show that energy spectrum...
Abstract With the aim of solving decade-old problem solar opacity, we report substantial photoabsorption uncertainty due to effect ion–ion correlations. By performing detailed opacity calculations mixture, find that taking into account ionic structure changes Rosseland near convection zone by ∼10%. We also a ∼15% difference in for iron, which was recently measured at Sandia Z facility, where temperature reached prevailing boundary while density 2.5 times lower. Finally, propose method...