DOCSLIB.ORG

Electron Magnetic Dipole Moment

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Electron Magnetic Dipole Moment Gabrielse Most Precise Tests of the Standard Model, Its Extensions and its Symmetries Gerald Gabrielse, Leverett Professor of Physics, Harvard University Spokesperson of the CERN ATRAP Collaboration Testing the Most Precise Prediction of the Standard Model Electron magnetic moment Testing standard model extensions Electron electric dipole moment Testing the Symmetries of the Standard Model Q/M for the antiproton and proton Antiproton and proton magnetic moments Positron and electron magnetic moments (underway) Antihydrogen and hydrogen structure (still in far future) Comparing Antimatter and Mater Gravity Gravitational Redshift of the Antiproton and Proton Supported by US NSF and AFOSR Gabrielse Low Energy Particle Physics AMO Physics, Particle Physics, Plasma Physics methods and funding goals and facility can’t avoid 2 2Mp c LEAR and AD 1010 TRAP 4.2 K 0.3 meV 70 mK, lowest storage energy for any charged particles Gabrielse Gabrielse Electron Magnetic Dipole Moment • Most precise prediction of the standard model • Most precisely measured property of an elementary particle • Most precise confrontation of theory and experiment • Greatest triumph of the standard model Gabrielse The Amazing Electron Electron orbits give atoms their size, but the electron itself may actually have no size 20000 electron masses 20 2 R2 10 m m* 10.3 TeV / c of binding energy for “ingredients” Electron has angular momentum (spin) even though it has no size and nothing is rotating: 2 S m R IA~ R2 Magnetic dipole moment: What about electric dipole? S S d d / 2 / 2 Gabrielse Standard Model of Prediction 2 3 4 5 e 1 CCCCC2 4 6 8 10 ... 2m B a hadronic a weak a new physics Dirac 1 QED essentially exact Hadronic Weak aweak smaller Gabrielse The Standard Model Predicts the Electron Magnetic Moment in terms of the 1e2 1 fine structure 4 c 137 constant 0 Gabrielse Probing 10th Order and Hadronic Terms Dirac QED Gabrielse David Hanneke G.G. Shannon Fogwell Gabrielse Need Good Students and Stable Funding Elise Novitski Joshua Dorr Shannon Fogwell Hogerheide David Hanneke Brian Odom, Brian D’Urso, 20 years Steve Peil, 8 theses Dafna Enzer, Kamal Abdullah Ching-hua Tseng Joseph Tan N$F Gabrielse Cylindrical Penning Trap V~ 2 z2 x 2 y 2 • Electrostatic quadrupole potential good near trap center • Control the radiation field inhibit spontaneous emission by 200x (Invented for this purpose: G.G. and F. C. MacKintosh; Int. J. Mass Spec. Ion Proc. 57, 1 (1984) Gabrielse Trap with One Electron Quantum Cyclotron -charges- - - - - - fc 150 GHz 2 n = 4 n = 3 n = 2 0.1 n = 1 m m hc 7.2 kelvin n = 0 y2 - - - - - - - Need low temperature B 6Tesla cyclotron motion T << 7.2 K 0.1 m m Gabrielse Quantum Measurement of the Electron Magnetic Moment S E ms s ( n 1/ 2) c / 2 Spin flip energy: BB 2 s s eB Cyclotron energy: c 2 B B c B (the magnetometer) m Bohr magneton e 2m Need to resolve the quantum states of the cyclotron motion Relativistic shift is 1 part in 109 per quantum level Gabrielse Quantum Jump Spectroscopy • one electron in a Penning trap • lowest cyclotron and spin states “In the dark” excitation turn off all detection and cooling drives during excitation Gabrielse Inhibited Spontaneous Emission Application of Cavity QED excite, measure time in excited state 30 t= 16 s 15 12 20 9 6 10 Y Axis 2 3 0 0 number of n=1 to n=0 decays -3 axial frequency shift (Hz) 0 10 20 30 40 50 60 0 100 200 300 decay time (s) time (s) many other new methods Most precisely measured property of an elementary particle Gabrielse Electron Magnetic Moment Measured to 3 x 10-13 2.8 1013 (improved measurement is underway) Gabrielse from measured fine structure constant Gabrielse From Freeman Dyson – One Inventor of QED Dear Jerry, ... I love your way of doing experiments, and I am happy to congratulate you for this latest triumph. Thank you for sending the two papers. Your statement, that QED is tested far more stringently than its inventors could ever have envisioned, is correct. As one of the inventors, I remember that we thought of QED in 1949 as a temporary and jerry-built structure, with mathematical inconsistencies and renormalized infinities swept under the rug. We did not expect it to last more than ten years before some more solidly built theory would replace it. We expected and hoped that some new experiments would reveal discrepancies that would point the way to a better theory. And now, 57 years have gone by and that ramshackle structure still stands. The theorists … have kept pace with your experiments, pushing their calculations to higher accuracy than we ever imagined. And you still did not find the discrepancy that we hoped for. To me it remains perpetually amazing that Nature dances to the tune that we scribbled so carelessly 57 years ago. And it is amazing that you can measure her dance to one part per trillion and find her still following our beat. With congratulations and good wishes for more such beautiful experiments, yours ever, Freeman. Gabrielse Test for Physics Beyond the Standard Model g 1 aQED () aSM: Hadronic Weak aNewPhysi c s B 2 Does the electron have internal structure? m* total mass of particles bound together to form electron m 2 limited by the uncertainty in R5 1019 m m* 360 GeV / c a independent a value m R2 1019 m m* 1 TeV / c2 if our uncertainty a was the only limit Not bad for an experiment done at 100 mK, but LEP does better R2 1020 m m* 10.3 TeV / c2 LEP contact interaction limit > 20000 electron masses of binding energy Gabrielse Gabrielse Electron Electric Dipole Moment • Most precise test of extensions to the standard model • 12 times more precise than previous measurements S S Magnetic moment: Electric dipole moment: d d / 2 / 2 Well measured Does this also exist? Gabrielse Particle EDM Requires Both P and T Violation Magnetic moment: Electric dipole Moment: S S d d / 2 / 2 If reality is invariant under parity transformations P P d = 0 T If reality is invariant under time reversal transformations T d = 0 Gabrielse Standard Model of Particle Physics Currently Predicts a Non-zero Electron EDM four-loop -38 Standard model: d ~ 10 e-cm level in perturbation Too small to measure by orders of magnitude theory best measurement: d ~ 2 x 10-27 e-cm Weak interaction couples quark pairs (generations) CKM matrix relates to d, s, b quarks (Cabibbo-Kabayashi-Maskawa matrix) almost the unit matrix Gabrielse Extensions to the Standard Model Much Bigger, Measureable Electron EDM An example Low order contribution larger moment Low order contribution vanishes From Fortson, Sandars and Barr, Physics Today, 33 (June 2003) Gabrielse New Electron EDM Measurement is Almost Done Gabrielse Advanced Cold-Molecule Electron EDM Harvard University Yale University John Doyle Group David DeMille Group Gerald Gabrielse Group Jacob Baron, Wes Campbell, David DeMille, John Doyle, Gerald Gabrielse, Paul Hess, Nick Hutzler, Emil Kirilov, Brendon O’Leary, Cris Panda, Elizabeth Petrik, Ben Spaun, Amar Vutha, Adam West Funding from NSF Gabrielse How to Measure an Electron EDM Put the EDM in an Electric Field bigger is better H d E Measure the energy shift for the system Gabrielse Cannot Use Electric Field Directly on an Electron or Proton Simple E and B can be used for neutron EDM measurement (neutron has magnetic moment but no net charge) Electric field would accelerate an electron out of the apparatus Electron EDM are done within atoms and molecules (first molecular ion measurement is now being attempted) Gabrielse Schiff Theorem – for Electron in an Atom or Molecule Schiff (1963) – no atomic or molecular EDM (i.e. linear Stark effect) • from electron edm • nonrelativistic quantum mechanics limit Sandars (1965) – can get atomic or molecular EDM (i.e. linear Stark effect) • from electron edm • relativistic quantum mechanics • get significant enhancement (D >> d) for large Z Commins, Jackson, DeMille (2007) – intuitive explanation Schiff Lorentz contraction of the electron EDM in lab frame Schiff, Phys. Rev. Lett. 132, 2194 (1963); Sandars, Phys. Rev. Lett. 14, 194 (1965); ibid 22, 290 (1966). Commins, Jackson, DeMille, Am. J. Phys. 75, 532 (2007). Gabrielse Why Use a Molecule? To Make Largest Possible Electric Field on Electron Tl atom (best EDM limit till YbF) ThO molecule Elab123 kV/cm E eff 72 MV/cm EGlab100 V/cm E eff 100 V/cm Molecule can be more easily polarized using nearby energy levels with opposite parity (not generally available in atoms) Gabrielse Detect the Energy Difference S two states evolve differently in time g / 2 i E t /hbar S e de d e / 2 Gabrielse Still, the EDM Gives Tiny Shift of Energy Levels 2 mHz E 7 1018 eV 7 1027 GeV Not so easy to resolve 7 1030 TeV To detect let a prepared wave function evolve for time T large as | (0) |1 | 2 | (T) |1ei | 2 possible E T T1.1 ms 11 106 0.6 10 3 degrees Example is for an electron edm equal the ACME upper limit. Gabrielse Experiment in Two Labs – 100 Meters Separated Harvard Jefferson Building Harvard LISE Building ThO Source and Interaction Chamber 100 m optical fibers (2 floors down) Lasers, Iodine Clock, Comb Gabrielse ThO Molecular Beam Pulse Tube Cooler Molecular Beam “Interaction Source Region”: E- field plates inside, B- field shields Pulsed and coils YAG outside Prep Lasers Probe Lasers Lasers 100m away 34 Gabrielse Magnetic Field Coils and Shielding mu metal 5 shields endplates (no shown) ~ 10-5 ThO beam shielding Interaction Cos(theta) chamber coils
Load more

Recommended publications
  • Magnetism, Angular Momentum, and Spin
    Chapter 19 Magnetism, Angular Momentum, and Spin P. J. Grandinetti Chem. 4300 P. J. Grandinetti Chapter 19: Magnetism, Angular Momentum, and Spin In 1820 Hans Christian Ørsted discovered that electric current produces a magnetic field that deflects compass needle from magnetic north, establishing first direct connection between fields of electricity and magnetism. P. J. Grandinetti Chapter 19: Magnetism, Angular Momentum, and Spin Biot-Savart Law Jean-Baptiste Biot and Félix Savart worked out that magnetic field, B⃗, produced at distance r away from section of wire of length dl carrying steady current I is 휇 I d⃗l × ⃗r dB⃗ = 0 Biot-Savart law 4휋 r3 Direction of magnetic field vector is given by “right-hand” rule: if you point thumb of your right hand along direction of current then your fingers will curl in direction of magnetic field. current P. J. Grandinetti Chapter 19: Magnetism, Angular Momentum, and Spin Microscopic Origins of Magnetism Shortly after Biot and Savart, Ampére suggested that magnetism in matter arises from a multitude of ring currents circulating at atomic and molecular scale. André-Marie Ampére 1775 - 1836 P. J. Grandinetti Chapter 19: Magnetism, Angular Momentum, and Spin Magnetic dipole moment from current loop Current flowing in flat loop of wire with area A will generate magnetic field magnetic which, at distance much larger than radius, r, appears identical to field dipole produced by point magnetic dipole with strength of radius 휇 = | ⃗휇| = I ⋅ A current Example What is magnetic dipole moment induced by e* in circular orbit of radius r with linear velocity v? * 휋 Solution: For e with linear velocity of v the time for one orbit is torbit = 2 r_v.
    [Show full text]
  • New Measurements of the Electron Magnetic Moment and the Fine Structure Constant
    S´eminaire Poincar´eXI (2007) 109 – 146 S´eminaire Poincar´e Probing a Single Isolated Electron: New Measurements of the Electron Magnetic Moment and the Fine Structure Constant Gerald Gabrielse Leverett Professor of Physics Harvard University Cambridge, MA 02138 1 Introduction For these measurements one electron is suspended for months at a time within a cylindrical Penning trap [1], a device that was invented long ago just for this purpose. The cylindrical Penning trap provides an electrostatic quadrupole potential for trapping and detecting a single electron [2]. At the same time, it provides a right, circular microwave cavity that controls the radiation field and density of states for the electron’s cyclotron motion [3]. Quantum jumps between Fock states of the one-electron cyclotron oscillator reveal the quantum limit of a cyclotron [4]. With a surrounding cavity inhibiting synchrotron radiation 140-fold, the jumps show as long as a 13 s Fock state lifetime, and a cyclotron in thermal equilibrium with 1.6 to 4.2 K blackbody photons. These disappear by 80 mK, a temperature 50 times lower than previously achieved with an isolated elementary particle. The cyclotron stays in its ground state until a resonant photon is injected. A quantum cyclotron offers a new route to measuring the electron magnetic moment and the fine structure constant. The use of electronic feedback is a key element in working with the one-electron quantum cyclotron. A one-electron oscillator is cooled from 5.2 K to 850 mK us- ing electronic feedback [5]. Novel quantum jump thermometry reveals a Boltzmann distribution of oscillator energies and directly measures the corresponding temper- ature.
    [Show full text]
  • The G Factor of Proton
    The g factor of proton Savely G. Karshenboim a,b and Vladimir G. Ivanov c,a aD. I. Mendeleev Institute for Metrology (VNIIM), St. Petersburg 198005, Russia bMax-Planck-Institut f¨ur Quantenoptik, 85748 Garching, Germany cPulkovo Observatory, 196140, St. Petersburg, Russia Abstract We consider higher order corrections to the g factor of a bound proton in hydrogen atom and their consequences for a magnetic moment of free and bound proton and deuteron as well as some other objects. Key words: Nuclear magnetic moments, Quantum electrodynamics, g factor, Two-body atoms PACS: 12.20.Ds, 14.20.Dh, 31.30.Jv, 32.10.Dk Investigation of electromagnetic properties of particles and nuclei provides important information on fundamental constants. In addition, one can also learn about interactions of bound particles within atoms and interactions of atomic (molecular) composites with the media where the atom (molecule) is located. Since the magnetic interaction is weak, it can be used as a probe to arXiv:hep-ph/0306015v1 2 Jun 2003 learn about atomic and molecular composites without destroying the atom or molecule. In particular, an important quantity to study is a magnetic moment for either a bare nucleus or a nucleus surrounded by electrons. The Hamiltonian for the interaction of a magnetic moment µ with a homoge- neous magnetic field B has a well known form Hmagn = −µ · B , (1) which corresponds to a spin precession frequency µ hν = B , (2) spin I Email address: [email protected] (Savely G. Karshenboim). Preprint submitted to Elsevier Science 1 February 2008 where I is the related spin equal to either 1/2 or 1 for particles and nuclei under consideration in this paper.
    [Show full text]
  • Class 35: Magnetic Moments and Intrinsic Spin
    Class 35: Magnetic moments and intrinsic spin A small current loop produces a dipole magnetic field. The dipole moment, m, of the current loop is a vector with direction perpendicular to the plane of the loop and magnitude equal to the product of the area of the loop, A, and the current, I, i.e. m = AI . A magnetic dipole placed in a magnetic field, B, τ experiences a torque =m × B , which tends to align an initially stationary N dipole with the field, as shown in the figure on the right, where the dipole is represented as a bar magnetic with North and South poles. The work done by the torque in turning through a small angle dθ (> 0) is θ dW==−τθ dmBsin θθ d = mB d ( cos θ ) . (35.1) S Because the work done is equal to the change in kinetic energy, by applying conservation of mechanical energy, we see that the potential energy of a dipole in a magnetic field is V =−mBcosθ =−⋅ mB , (35.2) where the zero point is taken to be when the direction of the dipole is orthogonal to the magnetic field. The minimum potential occurs when the dipole is aligned with the magnetic field. An electron of mass me moving in a circle of radius r with speed v is equivalent to current loop where the current is the electron charge divided by the period of the motion. The magnetic moment has magnitude π r2 e1 1 e m = =rve = L , (35.3) 2π r v 2 2 m e where L is the magnitude of the angular momentum.
    [Show full text]
  • Deuterium by Julia K
    Progress Towards High Precision Measurements on Ultracold Metastable Hydrogen and Trapping Deuterium by Julia K. Steinberger Submitted to the Department of Physics in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY August 2004 - © Massachusetts Institute of Technology 2004. All rights reserved. Author .............. Department of Physics Augulst 26. 2004 Certifiedby......... .. .. .. .. .I- . .... Thom4. Greytak Prof or of Physics !-x. Thesis SuDervisor Certified by........................ Danil/Kleppner Lester Wolfe Professor of Physics Thesis Supervisor Accepted by... ...................... " . "- - .w . A. ....... MASSACHUSETTS INSTITUTE /Thom . Greytak OF TECHNOLOGY Chairman, Associate Department Head Vr Education SEP 14 2004 ARCHIVES LIBRARIES . *~~~~ Progress Towards High Precision Measurements on Ultracold Metastable Hydrogen and Trapping Deuterium by Julia K. Steinberger Submitted to the Department of Physics on August 26, 2004, in partial fulfillment of the requirements for the degree of Doctor of Philosophy Abstract Ultracold metastable trapped hydrogen can be used for precision measurements for comparison with QED calculations. In particular, Karshenboim and Ivanov [Eur. Phys. Jour. D 19, 13 (2002)] have proposed comparing the ground and first excited state hyperfine splittings of hydrogen as a high precision test of QED. An experiment to measure the 2S hyperfine splitting using a field-independent transition frequency in the 2S manifold of hydrogen is described. The relation between the transition frequency and the hyperfine splitting requires incorporating relativistic and bound state QED corrections to the electron and proton g-factors in the Breit-Rabi formula. Experimental methods for measuring the magnetic field of an ultracold hydrogen sample are developed for trap fields from 0 to 900 G.
    [Show full text]
  • Antihydrogen and the Antiproton Magnetic Moment
    Gabrielse ATRAP: Context and Status Antihydrogen and the Antiproton Magnetic Moment Gerald Gabrielse Spokesperson for TRAP and ATRAP at CERN Levere tt Pro fesso r o f Phys ics, Har var d Uni ver sit y Gabrielse Context CERN Pursues Fundamental Particle Physics at WWeveegySceseesghatever Energy Scale is Interesting A Long and Noble CERN Tradition 1981 – traveled to Fermilab “TEV or bust” 1985 – different response at CERN wh en I went th ere to try to get access to LEAR antiprotons for qqyg/m measurements and cold antihydrogen It is exciting that there is now • a dedicated storaggge ring for antih ygpydrogen experiments • four international collaborations • too few antiprotons for the demand Gabrielse Pursuing Fundamental Particle Physics atWhtt Whatever Energy Sca le is In teres ting A Long and Noble CERN Tradition 1986 – First trapped antiprotons (TRAP) 1989 – First electron-cooling of trapped antiprotons (TRAP) 1 cm magnetic field 21 MeV antiprotons slow in matter degrader _ + _ CERN’s AD, plus these cold methods make antihydrogen possible Gabrielse Pursuing Fundamental Particle Physics atWhtt Whatever Energy Sca le is In teres ting A Long and Noble CERN Tradition 1981 – traveled to Fermilab “TEV or bust” 1985 – different response at CERN when I went there to try to get access to LEAR antiprotons for q/m measurements and cold antihydrogen LHC: 7 TeV + 7 TeV AD: 5 MeV 100 times 5 x 1016 More trapped ELENA upgrade: 0.1 MeV antiprotons ATRAP: 0.3 milli-eV Gabrielse Physics With Low Energy Antiprotons First Physics: Compare q/m for antiproton
    [Show full text]
  • Trapped Antihydrogen in Its Ground State
    Trapped Antihydrogen in Its Ground State The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Richerme, Philip. 2012. Trapped Antihydrogen in Its Ground State. Doctoral dissertation, Harvard University. Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:10058466 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Other Posted Material, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#LAA ©2012 - Philip John Richerme All rights reserved. Thesis advisor Author Gerald Gabrielse Philip John Richerme Trapped Antihydrogen in Its Ground State Abstract Antihydrogen atoms (H) are confined in a magnetic quadrupole trap for 15 to 1000 s - long enough to ensure that they reach their ground state. This milestone brings us closer to the long-term goal of precise spectroscopic comparisons of H and H for tests of CPT and Lorentz invariance. Realizing trapped H requires charac- terization and control of the number, geometry, and temperature of the antiproton (p) and positron (e+) plasmas from which H is formed. An improved apparatus and implementation of plasma measurement and control techniques make available 107 p and 4 × 109 e+ for H experiments - an increase of over an order of magnitude. For the first time, p are observed to be centrifugally separated from the electrons that cool them, indicating a low-temperature, high-density p plasma. Determination of the p temperature is achieved through measurement of the p evaporation rate as their con- fining well is reduced, with corrections given by a particle-in-cell plasma simulation.
    [Show full text]
  • Harvard University Department of Physics Newsletter
    Harvard University Department of Physics Newsletter FALL 2014 COVER STORY Probing the Universe’s Earliest Moments FOCUS Early History of the Physics Department FEATURED Quantum Optics Where Physics Meets Biology Condensed Matter Physics NEWS A Reunion Across Generations and Disciplines 42475.indd 1 10/30/14 9:19 AM Detecting this signal is one of the most important goals in cosmology today. A lot of work by a lot of people has led to this point. JOHN KOVAC, HARVARD-SMITHSONIAN CENTER FOR ASTROPHYSICS LEADER OF THE BICEP2 COLLABORATION 42475.indd 2 10/24/14 12:38 PM CONTENTS ON THE COVER: Letter from the former Chair ........................................................................................................ 2 The BICEP2 telescope at Physics Department Highlights 4 twilight, which occurs only ........................................................................................................ twice a year at the South Pole. The MAPO observatory (home of the Keck Array COVER STORY telescope) and the South Pole Probing the Universe’s Earliest Moments ................................................................................. 8 station can be seen in the background. (Steffen Richter, Harvard University) FOCUS ACKNOWLEDGMENTS Early History of the Physics Department ................................................................................ 12 AND CREDITS: Newsletter Committee: FEATURED Professor Melissa Franklin Professor Gerald Holton Quantum Optics ..............................................................................................................................14
    [Show full text]
  • Daily Newsletter – Wednesday, 29 July Neutrino Physics Flavour
    Daily Newsletter – Wednesday, 29 July The finale of a great conference in a wonderful related with the CKM-triangle. We expect city still has a lot to offer! Here comes the to see there the latest result published on overview. Monday in Nature Physics by the LHCb collaboration. The second presentation will summarise the rare decays and exotic Neutrino PhysiCs states, including information about the Sterile neutrinos with masses in different recently discovered pentaquark. Low energy ranges are physically very energy precision experiments, like interesting objects. Such neutrinos, with measurements of the lepton magnetic masses in the GeV range, could make an moment or studies using antihydrogen, important contribution to solving the will be summarised by Gerald Gabrielse. puzzle of matter-antimatter asymmetry in the universe, while keV-mass sterile neutrinos could constitute dark matter. Higgs and New PhysiCs The quest to find sterile neutrinos in the On the last day of the conference, two eV mass range, which might relieve talks will cover the experimental status of tensions in the findings of short baseline the search for new physics. experiments, is close to its end. The Supersymmetry is one of the best absolute neutrino mass scale of the three motivated extensions of the Standard standard neutrinos is still not known, Model and a first talk will provide though the possible range of the heaviest highlights of the searches for of the three has been narrowed down to supersymmetric particles performed so far the sub-eV range. The main objective of at the LHC. A second talk will give an experiments trying to find neutrinoless overview of the territory covered by the double beta decay is to discover whether LHC Run 1 searches for exotic neutrinos have Majorana nature, i.e., if experimental signatures in a large variety they are their own antiparticles.
    [Show full text]
  • The Possible Explanation for the Mysterious Hot Solar Corona
    Solar Physics DOI: 10.1007/•••••-•••-•••-••••-• A possible explanation for the mysterious hot solar corona Anil Raghav1 c Springer •••• Abstract The coronal heating has remained a puzzle for decades since its observation in 1940. Several space missions have been planned to resolve this conundrum in the past and many more intend to target this issue in the future. The unfolding of this issue will not only advance the fundamentals of astro- physical science but also promise an improvement in space weather prediction. Its origin has been debated without complete convergence; the acoustic waves, magneto-hydrodynamic waves, and micro/nano-flares are the strongest candi- dates so far to explain the mystery of coronal heating. However, none of these processes significantly justifies the million-degree temperature of the solar corona and the problem remains unsolved to date. Here, we propose a new physical mechanism to explain the observed heating of the solar corona. The statistical energy created during the interaction of the spin magnetic moment of the plasma particles with the turbulent and continuously evolving coronal magnetic field could substantiate the observed million-degree coronal temperature. Keywords: Corona, Magnetic fields The corona is the outermost layer of the Sun’s atmosphere, which can be observed as the thin white glow during a total solar eclipse (Saito & Tandberg- Hanssen, 1973). The spectroscopic measurements in 1940 discovered that the temperature of the corona is up to million degrees (Edl´en, 1937; Grotian, 1939; Lyot, 1939; Edl´en, 1945). Even eight decades after this discovery, here is still no concrete theory that explains this shooting up of temperature.
    [Show full text]
  • Fundamental Physical Constants — Complete Listing Relative Std
    From: http://physics.nist.gov/constants Fundamental Physical Constants — Complete Listing Relative std. Quantity Symbol Value Unit uncert. ur UNIVERSAL 1 speed of light in vacuum c; c0 299 792 458 m s− (exact) 7 2 magnetic constant µ0 4π 10− NA− × 7 2 = 12:566 370 614::: 10− NA− (exact) 2 × 12 1 electric constant 1/µ0c "0 8:854 187 817::: 10− F m− (exact) characteristic impedance × of vacuum µ / = µ c Z 376:730 313 461::: Ω (exact) p 0 0 0 0 Newtonian constant 11 3 1 2 3 of gravitation G 6:673(10) 10− m kg− s− 1:5 10− × 39 2 2 × 3 G=¯hc 6:707(10) 10− (GeV=c )− 1:5 10− × 34 × 8 Planck constant h 6:626 068 76(52) 10− J s 7:8 10− × 15 × 8 in eV s 4:135 667 27(16) 10− eV s 3:9 10− × 34 × 8 h=2π ¯h 1:054 571 596(82) 10− J s 7:8 10− × 16 × 8 in eV s 6:582 118 89(26) 10− eV s 3:9 10− × × 1=2 8 4 Planck mass (¯hc=G) mP 2:1767(16) 10− kg 7:5 10− 3 1=2 × 35 × 4 Planck length ¯h=mPc = (¯hG=c ) lP 1:6160(12) 10− m 7:5 10− 5 1=2 × 44 × 4 Planck time lP=c = (¯hG=c ) tP 5:3906(40) 10− s 7:5 10− × × ELECTROMAGNETIC 19 8 elementary charge e 1:602 176 462(63) 10− C 3:9 10− × 14 1 × 8 e=h 2:417 989 491(95) 10 AJ− 3:9 10− × × 15 8 magnetic flux quantum h=2e Φ0 2:067 833 636(81) 10− Wb 3:9 10− 2 × 5 × 9 conductance quantum 2e =h G0 7:748 091 696(28) 10− S 3:7 10− 1 × × 9 inverse of conductance quantum G0− 12 906:403 786(47) Ω 3:7 10− a 9 1 × 8 Josephson constant 2e=h KJ 483 597:898(19) 10 Hz V− 3:9 10− von Klitzing constantb × × 2 9 h=e = µ0c=2α RK 25 812:807 572(95) Ω 3:7 10− × 26 1 8 Bohr magneton e¯h=2me µB 927:400 899(37) 10− JT− 4:0 10− 1 × 5 1 × 9 in
    [Show full text]
  • Precision Pins Down the Electron's Magnetism
    CCOctELECTRON35-37 20/9/06 11:14 Page 35 PHYSICAL CONSTANTS Precision pins down the electron’s magnetism A measurement of the electron magnetic Dear Gerald…As one of the inventors [of QED], I remember that we thought of QED in 1949 as a temporary and jerry-built moment using the combination of several structure, with mathematical inconsistencies and renormalized leading-edge techniques has achieved new infinities swept under the rug. We did not expect it to last more than 10 years before some more solidly built theory would levels of accuracy, yielding a more precise replace it...Now, 57 years have gone by and that ramshackle structure still stands...It is amazing that you can measure her value for the fine structure constant. dance to one part per trillion and find her still following our beat. Gerald Gabrielse and David Hanneke With congratulations and good wishes for more such beautiful experiments, yours ever, Freeman Dyson. (Dyson 2006). describe this remarkable experiment. The electron’s magnetic moment has recently been measured to an of its low energy and by locating the electron in the centre of a accuracy of 7.6 parts in 1013 (Odom et al. 2006). As figure 1a microwave cavity. The damping time is typically about 10 seconds, (p36) indicates, this is a six-fold improvement on the last measure- about 1024 times slower than for a 104 GeV electron in the Large ment of this moment made nearly 20 years ago (Van Dyck et al. Electron–Positron collider (LEP). To confine the electron weakly we 1987).
    [Show full text]