Nucleus Nucleus the Massive, Positively Charged Central Part of an Atom, Made up of Protons and Neutrons
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Charge Radius of the Short-Lived Ni68 and Correlation with The
PHYSICAL REVIEW LETTERS 124, 132502 (2020) Charge Radius of the Short-Lived 68Ni and Correlation with the Dipole Polarizability † S. Kaufmann,1 J. Simonis,2 S. Bacca,2,3 J. Billowes,4 M. L. Bissell,4 K. Blaum ,5 B. Cheal,6 R. F. Garcia Ruiz,4,7, W. Gins,8 C. Gorges,1 G. Hagen,9 H. Heylen,5,7 A. Kanellakopoulos ,8 S. Malbrunot-Ettenauer,7 M. Miorelli,10 R. Neugart,5,11 ‡ G. Neyens ,7,8 W. Nörtershäuser ,1,* R. Sánchez ,12 S. Sailer,13 A. Schwenk,1,5,14 T. Ratajczyk,1 L. V. Rodríguez,15, L. Wehner,16 C. Wraith,6 L. Xie,4 Z. Y. Xu,8 X. F. Yang,8,17 and D. T. Yordanov15 1Institut für Kernphysik, Technische Universität Darmstadt, D-64289 Darmstadt, Germany 2Institut für Kernphysik and PRISMA+ Cluster of Excellence, Johannes Gutenberg-Universität Mainz, D-55128 Mainz, Germany 3Helmholtz Institute Mainz, GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt, Germany 4School of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, United Kingdom 5Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany 6Oliver Lodge Laboratory, Oxford Street, University of Liverpool, Liverpool L69 7ZE, United Kingdom 7Experimental Physics Department, CERN, CH-1211 Geneva 23, Switzerland 8KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium 9Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA and Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA 10TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3, Canada 11Institut -
Muonic Atoms and Radii of the Lightest Nuclei
Muonic atoms and radii of the lightest nuclei Randolf Pohl Uni Mainz MPQ Garching Tihany 10 June 2019 Outline ● Muonic hydrogen, deuterium and the Proton Radius Puzzle New results from H spectroscopy, e-p scattering ● Muonic helium-3 and -4 Charge radii and the isotope shift ● Muonic present: HFS in μH, μ3He 10x better (magnetic) Zemach radii ● Muonic future: muonic Li, Be 10-100x better charge radii ● Ongoing: Triton charge radius from atomic T(1S-2S) 400fold improved triton charge radius Nuclear rms charge radii from measurements with electrons values in fm * elastic electron scattering * H/D: laser spectroscopy and QED (a lot!) * He, Li, …. isotope shift for charge radius differences * for medium-high Z (C and above): muonic x-ray spectroscopy sources: * p,d: CODATA-2014 * t: Amroun et al. (Saclay) , NPA 579, 596 (1994) * 3,4He: Sick, J.Phys.Chem.Ref Data 44, 031213 (2015) * Angeli, At. Data Nucl. Data Tab. 99, 69 (2013) The “Proton Radius Puzzle” Measuring Rp using electrons: 0.88 fm ( +- 0.7%) using muons: 0.84 fm ( +- 0.05%) 0.84 fm 0.88 fm 5 μd 2016 CODATA-2014 4 μp 2013 5.6 σ 3 e-p scatt. μp 2010 2 H spectroscopy 1 0.83 0.84 0.85 0.86 0.87 0.88 0.89 0.9 Proton charge radius R [fm] ch μd 2016: RP et al (CREMA Coll.) Science 353, 669 (2016) μp 2013: A. Antognini, RP et al (CREMA Coll.) Science 339, 417 (2013) The “Proton Radius Puzzle” Measuring Rp using electrons: 0.88 fm ( +- 0.7%) using muons: 0.84 fm ( +- 0.05%) 0.84 fm 0.88 fm 5 μd 2016 CODATA-2014 4 μp 2013 5.6 σ 3 e-p scatt. -
The MITP Proton Radius Puzzle Workshop
Report on The MITP Proton Radius Puzzle Workshop June 2–6, 2014 in Waldthausen Castle, Mainz, Germany 1 Description of the Workshop The organizers of the workshop were: • Carl Carlson, William & Mary, [email protected] • Richard Hill, University of Chicago, [email protected] • Savely Karshenboim, MPI fur¨ Quantenoptik & Pulkovo Observatory, [email protected] • Marc Vanderhaeghen, Universitat¨ Mainz, [email protected] The web page of the workshop, which contains all talks, can be found at https://indico.mitp.uni-mainz.de/conferenceDisplay.py?confId=14 . The size of the proton is one of the most fundamental observables in hadron physics. It is measured through an electromagnetic form factor. The latter is directly related to the distribution of charge and magnetization of the baryon and through such imaging provides the basis of nearly all studies of the hadron structure. In very recent years, a very precise knowledge of nucleon form factors has become more and more im- portant as input for precision experiments in several fields of physics. Well known examples are the hydrogen Lamb shift and the hydrogen hyperfine splitting. The atomic physics measurements of energy level splittings reach an impressive accuracy of up to 13 significant digits. Its theoretical understanding however is far less accurate, being at the part-per-million level (ppm). The main theoretical uncertainty lies in proton structure corrections, which limits the search for new physics in these kinds of experiment. In this context, the recent PSI measurement of the proton charge radius from the Lamb shift in muonic hydrogen has given a value that is a startling 4%, or 5 standard deviations, lower than the values ob- tained from energy level shifts in electronic hydrogen and from electron-proton scattering experiments, see figure below. -
Physics Has a Core Problem
Physics Has a Core Problem Physicists can solve many puzzles by taking more accurate and careful measurements. Randolf Pohl and his colleagues at the Max Planck Institute of Quantum Optics in Garching, however, actually created a new problem with their precise measurements of the proton radius, because the value they measured differs significantly from the value previously considered to be valid. The difference could point to gaps in physicists’ picture of matter. Measuring with a light ruler: Randolf Pohl and his team used laser spectroscopy to determine the proton radius – and got a surprising result. PHYSICS & ASTRONOMY_Proton Radius TEXT PETER HERGERSBERG he atmosphere at the scien- tific conferences that Ran- dolf Pohl has attended in the past three years has been very lively. And the T physicist from the Max Planck Institute of Quantum Optics is a good part of the reason for this liveliness: the commu- nity of experts that gathers there is working together to solve a puzzle that Pohl and his team created with its mea- surements of the proton radius. Time and time again, speakers present possible solutions and substantiate them with mathematically formulated arguments. In the process, they some- times also cast doubt on theories that for decades have been considered veri- fied. Other speakers try to find weak spots in their fellow scientists’ explana- tions, and present their own calcula- tions to refute others’ hypotheses. In the end, everyone goes back to their desks and their labs to come up with subtle new deliberations to fuel the de- bate at the next meeting. In 2010, the Garching-based physi- cists, in collaboration with an interna- tional team, published a new value for the charge radius of the proton – that is, the nucleus at the core of a hydro- gen atom. -
Range of Usefulness of Bethe's Semiempirical Nuclear Mass Formula
RANGE OF ..USEFULNESS OF BETHE' S SEMIEMPIRIC~L NUCLEAR MASS FORMULA by SEKYU OBH A THESIS submitted to OREGON STATE COLLEGE in partial fulfillment or the requirements tor the degree of MASTER OF SCIENCE June 1956 TTPBOTTDI Redacted for Privacy lrrt rtllrt ?rsfirror of finrrtor Ia Ohrr;r ef lrJer Redacted for Privacy Redacted for Privacy 0hrtrurn of tohoot Om0qat OEt ttm Redacted for Privacy Dru of 0rrdnrtr Sohdbl Drta thrrlr tr prrrEtrl %.ifh , 1,,r, ," r*(,-. ttpo{ by Brtty Drvlr ACKNOWLEDGMENT The author wishes to express his sincere appreciation to Dr. G. L. Trigg for his assistance and encouragement, without which this study would not have been concluded. The author also wishes to thank Dr. E. A. Yunker for making facilities available for these calculations• • TABLE OF CONTENTS Page INTRODUCTION 1 NUCLEAR BINDING ENERGIES AND 5 SEMIEMPIRICAL MASS FORMULA RESEARCH PROCEDURE 11 RESULTS 17 CONCLUSION 21 DATA 29 f BIBLIOGRAPHY 37 RANGE OF USEFULNESS OF BETHE'S SEMIEMPIRICAL NUCLEAR MASS FORMULA INTRODUCTION The complicated experimental results on atomic nuclei haYe been defying definite interpretation of the structure of atomic nuclei for a long tfme. Even though Yarious theoretical methods have been suggested, based upon the particular aspects of experimental results, it has been impossible to find a successful theory which suffices to explain the whole observed properties of atomic nuclei. In 1936, Bohr (J, P• 344) proposed the liquid drop model of atomic nuclei to explain the resonance capture process or nuclear reactions. The experimental evidences which support the liquid drop model are as follows: 1. Substantially constant density of nuclei with radius R - R Al/3 - 0 (1) where A is the mass number of the nucleus and R is the constant of proportionality 0 with the value of (1.5! 0.1) x 10-lJcm~ 2. -
Neutron Deficient Exotic Nuclei and the Physics of the Proton Rich
Report on the second EURISOL User Group Topical Meeting 1 Neutron deficient exotic nuclei and the Physics of the proton rich side of the nuclear chart. Colegio Mayor Rector Peset, Valencia, Spain, 21-23 February 2011. The research leading to these results has received funding from the European Union Seventh Framework Programme FP7/2007- 2013 under Grant Agreement n. 262010 - ENSAR. The EC is not liable for any use that can be made on the information contained herein. The workshop was partially supported by CPAN and IFIC (CSIC-Univ. of Valencia), Spain. 1Coordinated by Berta Rubio, IFIC, Valencia, Spain and Angela Bonaccorso, INFN, Sez. di Pisa, Italy. 1 EURISOL SECOND TOPICAL MEETING “Neutron-deficient nuclei and the physics of the proton-rich side of the nuclear chart” Foreword This booklet contains the highlights of the second EURISOL Topical Meeting which was held in Valencia from 21st to 23rd February 2011. It followed the EURISOL Topical Meeting in Catania on “The formation and structure of r-process nuclei, between N=50 and 82 (including 78Ni and 132Sn areas)”. It was organised by the EURISOL Users Group and supported by the European Commission (ENSAR project), CPAN (Centro Nacional de Física de Partículas, Astropartículas y Nuclear, Spain) and IFIC (Instituto de Física Corpuscular, Spain). During the two and a half days of the meeting an interesting and dense programme was accommodated. Seventy participants, including almost all members of the previous and present EURISOL User Group Executive Committee contributed either to the presentations or to the lively discussions. The programme and the presentations are available at the workshop web site http://ific.uv.es/~eug-valencia. -
Electron Charge Density: a Clue from Quantum Chemistry for Quantum Foundations
Electron Charge Density: A Clue from Quantum Chemistry for Quantum Foundations Charles T. Sebens California Institute of Technology arXiv v.2 June 24, 2021 Forthcoming in Foundations of Physics Abstract Within quantum chemistry, the electron clouds that surround nuclei in atoms and molecules are sometimes treated as clouds of probability and sometimes as clouds of charge. These two roles, tracing back to Schr¨odingerand Born, are in tension with one another but are not incompatible. Schr¨odinger'sidea that the nucleus of an atom is surrounded by a spread-out electron charge density is supported by a variety of evidence from quantum chemistry, including two methods that are used to determine atomic and molecular structure: the Hartree-Fock method and density functional theory. Taking this evidence as a clue to the foundations of quantum physics, Schr¨odinger'selectron charge density can be incorporated into many different interpretations of quantum mechanics (and extensions of such interpretations to quantum field theory). Contents 1 Introduction2 2 Probability Density and Charge Density3 3 Charge Density in Quantum Chemistry9 3.1 The Hartree-Fock Method . 10 arXiv:2105.11988v2 [quant-ph] 24 Jun 2021 3.2 Density Functional Theory . 20 3.3 Further Evidence . 25 4 Charge Density in Quantum Foundations 26 4.1 GRW Theory . 26 4.2 The Many-Worlds Interpretation . 29 4.3 Bohmian Mechanics and Other Particle Interpretations . 31 4.4 Quantum Field Theory . 33 5 Conclusion 35 1 1 Introduction Despite the massive progress that has been made in physics, the composition of the atom remains unsettled. J. J. Thomson [1] famously advocated a \plum pudding" model where electrons are seen as tiny negative charges inside a sphere of uniformly distributed positive charge (like the raisins|once called \plums"|suspended in a plum pudding). -
Mirror Nuclei, A<=
Atomic Energy of Canada Limited MIRROR NUCLEI, A < 100 by J.C. HARDY Presented as an invited talk to the Canadian Association of Physicists meeting held in Montreal, June 18-21, 1973 Chalk River Nuclear Laboratories Chalk River, Ontario August 1973 AECL-4604 Atomic Energy of Canada Limited MIRROR NUCLEI, A <: 100 by J.C. HARDY Presented as an invited talk to the Canadian Association of Physicists meeting held in Montreal, June 18-21, 1973. Chalk River Nuclear Laboratories Chalk River, Ontario August 1973 AECL- Mirror Nuclei, A <, ICC by J.C Hardy ABSTRACT The effects of charge-dependent forces are described, and their dependence on the nuclear mass is discussed, it is proposed that large isospin impurities may occur in heavier nuclei (A <s 10G) with N ~ Z. several classes of p-decay experi- ment are sensitive to these effects, and a detailed description is given of recent chalk River experiments to study the super- allowed decay of 0*, T7 = -1 nuclei. This work has included the first measurement of mirror Fermi decay branches within a T = 1 multiplet. These and other data on superallowed p-decay are analyzed with particular emphasis on the charge dependent corrections to which mirror comparisons are particularly sensitive. The results are discussed in terms of the theory of weak interactions and the question of the existence of a heavy intermediate vector boson. It is suggested that some discrepancies for nuclei with A > 40 may be attributed to the proposed increase in charge dependent mixing. Some other experimental evidence suggesting the same conclusion is also given. -
Relativistic Deformed Mean-Field Calculation of Binding Energy Differences of Mirror Nuclei
Instituto de Física Teórica IFT Universidade Estadual Paulista IFT-P.003/96 TAUP-2310-95 Relativistic deformed mean-field calculation of binding energy differences of mirror nuclei W. Koepf School of Physics and Astronomy Tel Aviv University 69978 Ramat Aviv Israel G. Krein Instituto de Física Teórica Universidade Estadual Paulista Rua Pamplona 145 01405-900 - São Paulo, S.P. Brazil and L. A. Barreiro Instituto de Física Universidade de São Paulo Caixa Postal 66318 05389-970 - São Paulo, S.P. Brazil ? 7 US 1 Instituto de Física Teórica Universidade Estadual Paulista Rua Pamplona, 145 01405-900 - São Paulo, S.P. Brazil Telephone: 55 (11) 251.5155 Telefax: õõ (11) 288.8224 Telex: 55 (11) 31870 UJMFBR Electronic Address: [email protected] 47857::LIBRARY TAUP-2310-95, IFT-P.003/96,nucI-th/9601027 1. Introduction. Conventional nuclear theory, based on the Schrodingcr equation, 1ms difficulties in explaining the binding energy differences of mirror nuclei [1,2]. The major Relativistic deformed mean-field calculation of binding energy contribution to the energy difference comes from the Coulomb force, and a variety of isospm differences of mirror nuclei breaking effects provide small contributions. The difficulty in reproducing the experimental values is kaown in the literature as the Okamofco-Nolen-Schiffer anomaly (ONSA). Several W. Koepf nuclear structure effects such as correlations, core polarization and isospin mixing have been School of Physics and Astronomy, Tel Aviv University, 69978 Ramat Aviv, Israel invoked to resolve the anomaly without success [3]. Since Okamoto and Pask [4] and Negele [5] suggested that the discrepancy could he G. -
S Ince the Brilliant Insights and Pioneering
The secret life of quarks ince the brilliant insights and pioneering experiments of Geiger, S Marsden and Rutherford first revealed that atoms contain nuclei [1], nuclear physics has developed into an astoundingly rich and diverse field. We have probed the complexities of protons and nuclei in our laboratories; we have seen how nuclear processes writ large in the cosmos are key to our existence; and we have found a myriad of ways to harness the nuclear realm for energy, medical and security applications. Nevertheless, many open questions still remain in nuclear physics— the mysterious and hidden world that is the domain of quarks and gluons. 44 ) detmold mit physics annual 2017 The secret life by William of quarks Detmold The modern picture of an atom includes multiple layers of structure: atoms are composed of nuclei and electrons; nuclei are composed of protons and neutrons; and protons and neutrons are themselves composed of quarks—matter particles—that are held together by force- carrying particles called gluons. And it is the primary goal of the Large Hadron Collider (LHC) in Geneva, Switzerland, to investigate the tantalizing possibility that an even deeper structure exists. Despite this understanding, we are only just beginning to be able to predict the properties and interactions of nuclei from the underlying physics of quarks and gluons, as these fundamental constituents are never seen directly in experiments but always remain confined inside composite particles (hadrons), such as the proton. Recent progress in supercomputing and algorithm development has changed this, and we are rapidly approaching the point where precision calculations of the simplest nuclear processes will be possible. -
Rpp2020-List-Pi-Plus-Minus.Pdf
Citation: P.A. Zyla et al. (Particle Data Group), Prog. Theor. Exp. Phys. 2020, 083C01 (2020) G P − − π± I (J ) = 1 (0 ) We have omitted some results that have been superseded by later experiments. The omitted results may be found in our 1988 edition Physics Letters B204 1 (1988). ± π± MASS The most accurate charged pion mass measurements are based upon x- − ray wavelength measurements for transitions in π -mesonic atoms. The observed line is the blend of three components, corresponding to different K-shell occupancies. JECKELMANN 94 revisits the occupancy question, with the conclusion that two sets of occupancy ratios, resulting in two dif- ferent pion masses (Solutions A and B), are equally probable. We choose the higher Solution B since only this solution is consistent with a positive mass-squared for the muon neutrino, given the precise muon momentum measurements now available (DAUM 91, ASSAMAGAN 94, and ASSAM- AGAN 96) for the decay of pions at rest. Earlier mass determinations with pi-mesonic atoms may have used incorrect K-shell screening corrections. Measurements with an error of > 0.005 MeV have been omitted from this Listing. VALUE (MeV) DOCUMENT ID TECN CHG COMMENT 139..57039±0..00018 OUR FIT Error includes scale factor of 1.8. 139..57039±0..00017 OUR AVERAGE Error includes scale factor of 1.6. See the ideogram below. ± 1 + → + 139.57021 0.00014 DAUM 19 SPEC π µ νµ 139.57077±0.00018 2 TRASSINELLI 16 CNTR X-ray transitions in pionic N2 139.57071±0.00053 3 LENZ 98 CNTR − pionic N2-atoms gas target − 139.56995±0.00035 4 JECKELMANN94 CNTR − π atom, Soln. -
A Broken Nuclear Mirror to Ornithine Being Mobilized in Cytoplasmic Pathways Leading to Spermidine Production
Spermidine is a type of molecule called a adenosine-receptor expression and function forged in life; what other chains are forged in polyamine. It is mainly produced from a meta- between the species8, and therefore efforts to cell death? bolic pathway that converts the amino acid use these metabolites to treat human disease arginine to polyamines through intermediates might prove challenging. Douglas R. Green is in the Department of that include the molecule ornithine (Fig. 1). Medina and colleagues’ work opens rich Immunology, St. Jude Children’s Research Medina and colleagues traced the conversion possibilities for future investigations into Hospital, Memphis, Tennessee 38105, USA. of arginine to spermidine by this pathway, and how apoptosis triggers metabolic changes, e-mail: [email protected] found that cells induced to undergo apoptosis and how the regulated release of metabolites increased their synthesis of spermidine and its influences tissues. In contrast to apoptosis, 1. Medina, C. B. et al. Nature 580, 130–135 (2020). precursor, the molecule putrescine, before other forms of cell death, such as regulated 2. Green, D. R. Cell Death: Apoptosis and Other Means to an dying. The apoptotic cells released spermi- forms of necrosis, have profoundly different End 2nd edn (Cold Spring Harb. Lab. Press, 2018). 3. Lüthi, A. U. & Martin, S. J. Cell Death Differ. 14, 641–650 dine, but not putrescine. Spermidine release effects on surrounding cells, and whether (2007). occurred in a PANX1-dependent manner. and how changes in metabolism triggered 4. Kerr, J. F. R., Wyllie, A. H. & Currie, A. R. Br. J. Cancer 26, Although this phenomenon was monitored by those cell-death pathways influence their 239–257 (1972).