The Mnp Model Abstract

Total Page:16

File Type:pdf, Size:1020Kb

The Mnp Model Abstract The mnp Model An Attempt to Create a Radically Reduced Instruction Set for the Universe - or - Three Entities, Three Effects, One Universe An Architecture for the Fine Grained Structure of Everything Gregg Hauser Draft 20b: 2012-12-12 Abstract The mnp Model is offered as a conceptual structure for understanding the universe. The mnp Model has two principles, three new and tiny entities, and three new and short range interactions between those entities. The principles, entities, and effects are explained. The effect directions and ranges and how those effects work and lead to the basic structures of matter and fields are shown. The many failures considered in the development of the mnp Model are also documented, both to support the effectiveness of the current conceptual structure and in hopes that others can critique and avoid the dead ends encountered. Some of physic's givens, such as mass, movement and the Lorentz transformations involved, inertia, conversion of mass and energy, fields from moving masses and moving charges, relativistic mass, quark charge, nucleon structure, weak and strong interactions, have simple geometric explanations in the mnp Model. MUCH work remains. The Model initially avoids the use of familiar terms for new concepts, hence terms \entities" for tiny particles, “effects” or interactions instead of forces. The Model is considered by the author to be \almost complete" in concept, lacking any \proof of concept" in the form of calculation and modeling. The documents are currently undergoing remodeling based on a new image of the effect leading to gravity, on a new image of the structure of electrons and the charge structure of quarks, on a new image of the unification of weak and strong forces, and on a change in the image of the basic structure of neutrinos. Gravity, electro-static, magnetic, electro-magnetic, weak, and strong forces are described. Residual Strong Force is still poorly understood. Tiny neutrinos remain a mystery. Vestiges of the \old" Model and old vocabulary remain. Abstract - long form The mnp Model is new and not new. \No one is thinking like this," yet preon models were considered in the 1980's. String theory and quantum loop gravity have been seeking simplicity and descriptive power for some time. Poincar´e's\New Mechanics" of 1905, often referred to as LET or Lorentz Ether Theory, is considered experimentally indistinguishable from Special Relativity though SR is currently preferred. The mnp Model contains interesting suggestions for many current puzzles but also challenges orthodoxy in many ways. The conceptual structure is used to describe photons, charge, magnetism, electrons, and Dirac spin. The \hidden variable" in paired particles is explained. A structure is proposed for muons and small and large quarks. A reordering of generations of quarks is suggested. The mnp Model suggests gravity results in a non-intuitive way from the tendency of the entities to align their direction of travel. Densities never become infinite. Light is seen as \slowing" passing a mass by taking a longer route. Particles in deep space may accelerate significantly if already traveling toward the mass, black holes are porous but destroy \elementary" particles, and extra dimensions do not seem to be needed to explain current experiment. Dark matter and energy are pictured as unorganized accumulations of the basic entities. The photon of optics is shown as having structure, constantly creating magnetic and electric fields which then propagate and attenuate themselves. Those fields help organize the entities into a complete photon when it is first created. The mnp Model 1 2012-12-12 Hauser electric and magnetic fields also influence (mostly subsequent) photons. Photons continue to create new fields as they travel. Fields have no net translation or spin but do have structure, so do not affect or take energy from the particles that create them until a disturbance or measurement is made. Due to the stochastic nature of interactions in the mnp Model, the probabilistic nature of the fields and the location of the photon as described in QED are not supplanted. The mnp Model does provide descriptions of charge and electromagnetism that should eventually become visible and accessible to the merely gifted student. The author claims careful consideration of the double slit experiment led to this new structural image of the photon and its fields. Time dilation is a function of the structure of matter and movement at all speeds. Length compression must occur if the basic entities and their coiled organization is preserved. The basic entities have a constant speed, so rest mass derives from rotating in place. Motion and kinetic energy arise from redirecting those entities, which at c no longer rotate and so have no \resting" mass. This differs, to the author's dismay, from modern descriptions of energy, momentum and mass. The Model's description of time dilation and length contraction are consistent with the Michelson-Morley experiments and the very precise successors, but suggest a non-relativistic interpretation. One way speed of light experiments, considered impossible by many, are not accurate enough to measure the tiny differences in the measured speed of light due to the earth's rotation and orbit expected by the Model. The electron is described as a hollow surface with a single flat coiled filament made up of negative charge entities, with spin either right or left, capable of expanding in a shell, twisting into higher energy shells, responding to spin measurements, reverting quickly to a tiny sphere, and maintaining its unity at relativistic speeds. The Model suggests that the basic structural unit of particles is a loop of charge material 1/6 of an elementary charge which combine as six loops into a strand with hexagonal cross section to form the structure of electrons, positrons, and the small quarks through strange. The Model describes the weak force as exchange of charge material loops, the strong force as the same process interrupted by the presence of a compatible third quark, and the spontaneous appearance of positron-electron pairs as similar to neutron decay. The Model suggests why nucleons tend to be left handed in our region of the universe, and attempts to suggest why up, down, and electrons predominate over anti-up, anti-down, and positrons, at least in our region of the universe. The Model suggests a structural nature of muons, W and Z bosons as being similar to the quarks, though it has no need for elusive mediators. Some of the newest material is in Appendix C, \Current Blog Articles." Appendix A addresses many of the \unsolved problems in physics" with comments of varying quality, from interesting to wild guessing. The mnp Model does not yet include relative magnitudes of the forces or distances over which the three effects operate. The \size" or \mass" or \count" of figments need not be determined until the Model is complete and ready to be scaled to the real universe. The mnp Model insists that ALL distances of interaction will be small and ALL forces will act locally. Determining the details and magnitudes of the Computational mnp Model will take some time. Other models and theories of unification may benefit from the mnp Model's investigation of relevant phenomena and its structural explanations of perceived distance effects and spacial distortions. The Standard Model might even benefit from an approach based on spin connection and sixths of an elementary charge \mixed in a way we cannot see." This could make current particle theory and QCD interesting. If the strong force arises due to incomplete exchange of quantized sixths and the weak force from complete exchange, bringing calculation to a simplified Quantum Chromo Dynamics might be possible, though this requires seeing the weak and strong forces as contact rather than mediated interactions. Thanks to the Giants The author thanks the giants who have done so much careful experimentation and the giants who have worked to explain the experimental results and who have provided the vocabulary, grammar, and mathematics to describe those results. If the mnp Model cannot eventually confirm those experimental results and predict others, its conceptual beauty will be for naught. The author can be contacted through the blog mnpmodel.blogspot.com or the gmail address mnpmodel. mnp Model 2 2012-12-12 Hauser Contents Abstract . .1 List of Figures . .5 Version Release Notes . .6 1 Introduction 11 Conventions . 12 Predecessors to the mnp Model............................................. 13 mnp Model Must Arrive Fully Formed - As A Quantum . 13 When Does a Model Deserve Attention? . 13 When Does a Model Deserve Serious Attention? - The Big Five . 14 When Does a Model Deserve Acceptance? . 14 When Does a Model Deserve Publication in the Popular Press? . 15 When Does a Model Start to Look Viable? . 15 Getting Started With mnp ............................................... 15 2 mnp Model Summary 16 Principles . 16 Effects........................................................... 17 3 mnp Building Blocks 19 4 Thinking in the mnp Model 22 Mental Leaps Required in a Structural Model (2012-10-22) . 22 Counter Intuitive Effects of Effects Requires New Thought Patterns . 25 5 Familiar \Elementary Particles" in the mnp Model 27 Light is a \Particle" that Creates Fields and Waves and is then Influenced . 27 Electrons . 28 Paired Particles . 29 Neutrinos in the mnp Model............................................... 29 6 Fields and Traditional Forces in the mnp Model 31 Movement and Time Dilation . 32 Fine-Structure Constant in the mnp Model ...................................... 39 Strong Nuclear Force in the mnp Model........................................ 40 Electro-Weak Force in the mnp Model (2012-12-12) . 40 Weak Force in the mnp Model (2012-12-11) . 40 Gravity in the mnp Model................................................ 42 7 Phenomena, Large and Small, in the mnp Model 43 Dark Matter in the mnp Model............................................. 43 Black Holes in the mnp Model ............................................
Recommended publications
  • Asymptotic Freedom, Quark Confinement, Proton Spin Crisis, Neutron Structure, Dark Matters, and Relative Force Strengths
    Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 17 February 2021 doi:10.20944/preprints202102.0395.v1 Asymptotic freedom, quark confinement, proton spin crisis, neutron structure, dark matters, and relative force strengths Jae-Kwang Hwang JJJ Physics Laboratory, Brentwood, TN 37027 USA Abstract: The relative force strengths of the Coulomb forces, gravitational forces, dark matter forces, weak forces and strong forces are compared for the dark matters, leptons, quarks, and normal matters (p and n baryons) in terms of the 3-D quantized space model. The quark confinement and asymptotic freedom are explained by the CC merging to the A(CC=-5)3 state. The proton with the (EC,LC,CC) charge configuration of p(1,0,-5) is p(1,0) + A(CC=-5)3. The A(CC=-5)3 state has the 99.6% of the proton mass. The three quarks in p(1,0,-5) are asymptotically free in the EC and LC space of p(1,0) and are strongly confined in the CC space of A(CC=-5)3. This means that the lepton beams in the deep inelastic scattering interact with three quarks in p(1,0) by the EC interaction and weak interaction. Then, the observed spin is the partial spin of p(1,0) which is 32.6 % of the total spin (1/2) of the proton. The A(CC=-5)3 state has the 67.4 % of the proton spin. This explains the proton spin crisis. The EC charge distribution of the proton is the same to the EC charge distribution of p(1,0) which indicates that three quarks in p(1,0) are mostly near the proton surface.
    [Show full text]
  • Hadron Structure in Deep Inelastic Scattering
    Hadron Structure in Deep Inelastic Scattering Andrew Casey School of Chemistry & Physics University of Adelaide A thesis submitted as a portfolio of publications for the degree of Doctor of Philosophy August 2013 Contents Contentsi Dedication iv Abstractv Statement of Originality vii Acknowledgement ix List of Figuresx 1 Contextual Statement1 1.1 Contextual Statement . .1 1.1.1 Calculating Dihadron Fragmentation Function in the NJL- jet model . .1 1.1.2 Dihadron Fragmentation Functions from the NJL-jet model and their QCD Evolution . .2 1.1.3 Gluon Polarization in the Proton . .2 2 QCD and the Parton Model3 2.1 History . .3 2.2 Quantum Chromodynamics . .4 2.2.1 QCD Lagrangian . .5 2.2.2 Running of αs and Asymptotic Freedom . .8 2.3 Experimental Processes . 10 i CONTENTS 2.3.1 Overview . 10 2.3.2 QCD Factorization Theorem . 10 2.3.3 Deep Inelastic Scattering . 12 2.3.4 Semi-Inclusive Deep-Inelastic Scattering . 16 2.4 Parton Model . 18 2.4.1 Infinite Momentum Frame . 18 2.4.2 Bjorken Scaling . 20 2.4.3 DGLAP Evolution Equations . 20 2.4.3.1 Parton Distribution Function Evolution Equations 22 2.4.3.2 Single Hadron Fragmentation Function Evolution Equations . 25 2.4.3.3 Dihadron Fragmentation Function Evolution Equa- tions . 27 2.5 Proton Spin Crisis . 30 2.5.1 Polarization of the Gluon in the Proton . 31 3 Nambu{Jona-Lasinio model 34 3.1 Concepts and Properties of the Nambu{Jona-Lasinio model . 34 3.1.1 Nambu{Jona-Lasinio Model Lagrangian . 35 3.1.2 Mass Gap Equation .
    [Show full text]
  • The Spin Structure of the Proton from Lattice QCD
    19th International Spin Physics Symposium (SPIN2010) IOP Publishing Journal of Physics: Conference Series 295 (2011) 012009 doi:10.1088/1742-6596/295/1/012009 The spin structure of the proton from lattice QCD Philipp H¨agler Institut f¨urTheoretische Physik T39, Physik-Department der TU M¨unchen, James-Franck-Strasse, D-85747 Garching, Germany and Institut f¨urTheoretische Physik, Universit¨atRegensburg, D-93040 Regensburg, Germany E-mail: [email protected] Abstract. This proceeding discusses recent achievements in lattice QCD calculations of the longitudinal and transverse spin structure of the nucleon. Starting from the latest lattice results on moments of generalized parton distributions, we focus on the decomposition of the proton spin 1=2 in terms of quark (and gluon) spin and orbital angular momentum contributions. Recent results on the transverse nucleon spin structure obtained from lattice studies of transverse momentum distributions will be discussed and illustrated in the form of spin densities of quarks in the proton. We compare the results with expectations from phenomenological and model studies, and point out the most important systematic uncertainties and remaining challenges in the lattice approach. 1. Introduction In this contribution, we illustrate the advances that have been made in lattice QCD calculations of hadron structure by presenting and discussing a small number of results from recent dynamical lattice studies on the longitudinal and transverse spin structure of the nucleon. For more detailed accounts of the progress that has been made on the lattice, in particular with respect to the quark and gluon structure of the pion and the nucleon, we refer to [1, 2, 3, 4, 5, 6].
    [Show full text]
  • The Spin of the Proton
    The spin of the proton Bo-Qiang Ma (马伯强) Peking Univ (北京大学) ? The 7th Workshop on Hadron Physics in China and Opportunities Worldwide August 3-7, 2015, Duke Kunshan University Collaborators: Enzo Barone, Stan Brodsky, Jacques Soffer, Andreas Schafer, Ivan Schmidt, Jian-Jun Yang, Qi-Ren Zhang and students: Bowen Xiao, Zhun Lu, Bing Zhang, Jun She, Jiacai Zhu, Xinyu Zhang, Tianbo Liu 3 It has been 30 years of the proton “spin crisis” or “spin puzzle” • Spin Structure: experimentally u d s 0.020 u d s 0.3 spin “crisis” or “puzzle”: where is the proton’s missing spin? The Proton “Spin Crisis” In contradiction with the naïve quark model expectation: u d s 0.3 Why there is the proton spin puzzle/crisis? • The quark model is very successful for the classification of baryons and mesons • The quark model is good to explain the magnetic moments of octet baryons • The quark model gave the birth of QCD as a theory for strong interaction So why there is serious problem with spin of the proton in the quark model? The parton model (Feynman 1969) Infinite • photon scatters incoherently off Momentum massless, pointlike, spin-1/2 quarks Frame • probability that a quark carries fraction of parent proton’s momentum is q(), (0< < 1) 1 2 2 F2 (x) d eq q( ) (x ) eq x q(x) 0 q,q q,q 4 1 1 xu(x) x d(x) x s(x) ... 9 9 9 •the functions u(x), d(x), s(x), … are called parton distribution functions (pdfs) - they encode information about the proton’s deep structure •Parton model is established under the collinear approxiamtion: The transversal motion of partons is neglected or integrated over.
    [Show full text]
  • The Electron Ion Collider (EIC)
    7/18/16 EIC Lecture 2 at NNPSS 2016 at MIT 1 The Electron Ion Collider (EIC) Abhay Deshpande Lecture 2: What do we need polarized beams? Nucleon Spin Structure: What’s the problem? 2. Quantum Chromodynamics: The Fundamental Description of the Heart of Visible Matter Sidebar 2.6: Nucleon Spin: So Simple and Yet So Complex The simple fact that the proton carries spin 1/2, quark spins to account for most of the proton’s spin measured in units of Planck’s famous constant, is but were quite surprised when experiments at CERN exploited daily in thousands of magnetic resonance and other laboratories showed that the spins of all imaging images worldwide. Because the proton is a quarks and antiquarks combine to account for no more composite system, its spin is generated from its quark than about 30% of the total. This result has led nuclear 7/18/16 EIC Lecture 2 at NNPSS 2016 at MIT and gluon constituents. Physicists’ evolving appreciation scientists2. Quantum to address Chromodynamics: the more daunting The Fundamental challenges2 Description of the Heart of Visible Matter of how the spin might be generated, and of how much involved in measuring the other possible contributions to we have yet to understand about it, is an illustrative the spin illustrated in Figure 1. The gluons also have an Thecase study nucleon of how seemingly simple spin properties of visible intrinsic spin (1 unit) and might be “polarized” (i.e., might matter emerge from complex QCD interactions. have a preferential orientation of their spins along or puzzle….
    [Show full text]
  • Pos(SPIN2018)123 ∗ Speaker
    The Non-existence of the Proton Spin Crisis PoS(SPIN2018)123 Elliot Leader∗ Imperial College London [email protected] The spin crisis arose some 30 years ago following results of a European Muon Collaboration ex- periment on polarized DIS. Since then many people have pointed out that the arguments involved are too naive, yet papers continue to appear devoted to “the spin crisis". We explain the subtleties involved in giving a precise statement of the spin sum rule and clarify why there is really no crisis. 23rd International Spin Physics Symposium - SPIN2018 - 10-14 September, 2018 Ferrara, Italy ∗Speaker. c Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0). https://pos.sissa.it/ Spin Crisis Elliot Leader The controversy began some decades ago when the European Muon Collaboration (EMC) published results of their experiment on polarized fully inclusive DIS, which suggested that the constituents of the proton could not provide enough angular momentum to explain the fact that the proton had spin 1/2. And so 30 years ago Mauro Anselmino and E.L. published a paper in response to the results of the EMC experiment entitled A crisis in the parton model: Where, oh where is the proton’s spin?[1]. However, it has long been understood that there is no such crisis. Nonetheless papers keep appear- ing referring to “The proton spin crisis" . Why?????? Because people have forgotten that the belief in a spin-crisis emerged from an over naive interpre- PoS(SPIN2018)123 tation of the EMC experiment.
    [Show full text]
  • Curriculum Vitæ
    Curriculum vit½ Carl Johan Hansson BORN: November 16, 1966, in Luleºa,Sweden, Swedish citizen EXAMINA: High School Diploma (\gymnasieexamen") at Tornedalsskolan High School, Ha- paranda 1985 High School Diploma (\gymnasieingenjÄor",4-ºarigmaskinteknisk gren), fourth year at Midskogsskolan High School, Luleºa1986 Bachelor of Science (\¯loso¯e kandidat") in Physics at Uppsala University, Jan- uary 1993 Licentiate in Physics (\teknologie licentiat"), LuleºaUniversity of Technology, May 1996 Doctor of Philosophy in Physics, Ph.D. (\teknologie doktor"), LuleºaUniversity of Technology, March 1998. Faculty opponent: Professor Boris Kopeliovich, Max-Planck-Institut fÄurKernphysik, Heidelberg, Germany Associate Professor in Physics (\docent"), LuleºaUniversity of Technology, June 2005. THESES: Licentiate in Physics (\teknologie licentiat"), LuleºaUniversity of Technology, May 1996. Title: \The Proton as a Laboratory for the Fundamental Structure of Matter" 1996:05 L, ISSN 0280-8242 Doctor of Philosophy in Physics, Ph.D. (\teknologie doktor"), LuleºaUniversity of Technology, March 1998. Title: \The Fundamental Structure of Matter" 1998:04, ISSN 1402-1544, ISRN: LTU-DT{98/4{SE Thesis advisor: Professor Sverker Fredriksson EMPLOYMENTS: Teacher in ¯rst and secondary school (\lºag-,mellan- och hÄogstadiet"),on an hourly basis (\vikarie"), Haparanda, Sweden, 1985-88 Teacher (full time) in Mathematics and Physics in secondary school (\hÄogstadiet"), Bºalsta,Sweden, Aug - Dec 1991 PhD student employment (\doktorandtjÄanst"),Department of Physics, Luleºa
    [Show full text]
  • Nucleon Spin Structure Longitudinal Spin of the Proton
    Nucleon Spin Structure Longitudinal Spin of the Proton HUGS Summer School Jefferson National Laboratory June 1, 2011 Lecture 2 Abhay Deshpande Wednesday, June 1, 2011 Introduction & Overview (I) Abhay Deshpande, Nucleon Spin Lecture 2 of 6 at HUGS 2011 6/01/11 2 Wednesday, June 1, 2011 Introduction & Overview (I) • Lecture 1: Introduction & importance to “spin” – What is the spin crisis? Abhay Deshpande, Nucleon Spin Lecture 2 of 6 at HUGS 2011 6/01/11 2 Wednesday, June 1, 2011 Introduction & Overview (I) • Lecture 1: Introduction & importance to “spin” – What is the spin crisis? • Lecture 2 & Lecture 3 – Experimental method : Fixed Target Polarized Deep Inelastic Scattering (pDIS): early investigations – Spin Crisis, and the insights it enabled…. – Latest on pDIS experiments: result summaries – Principle limitations of fixed target experiments Abhay Deshpande, Nucleon Spin Lecture 2 of 6 at HUGS 2011 6/01/11 2 Wednesday, June 1, 2011 Introduction & Overview (II) Abhay Deshpande, Nucleon Spin Lecture 2 of 6 at HUGS 2011 6/01/11 3 Wednesday, June 1, 2011 Introduction & Overview (II) • Lecture 4 & Lecture 5 – Relativistic Heavy Ion Collider as a Polarized Collider – Comments experimental techniques – Review of results – Principle limitations Abhay Deshpande, Nucleon Spin Lecture 2 of 6 at HUGS 2011 6/01/11 3 Wednesday, June 1, 2011 Introduction & Overview (II) • Lecture 4 & Lecture 5 – Relativistic Heavy Ion Collider as a Polarized Collider – Comments experimental techniques – Review of results – Principle limitations • Lecture 6: Future
    [Show full text]
  • Lattice QCD Method to Study Proton Spin Crisis
    Lattice QCD Method To Study Proton Spin Crisis Gouranga C Nayak, ∗ (Dated: June 11, 2019) Abstract The proton spin crisis remains an unsolved problem in particle physics. The spin and angular momentum of the partons inside the proton are non-perturbative quantities in QCD which cannot be calculated by using the perturbative QCD (pQCD). In this paper we present the lattice QCD formulation to study the proton spin crisis. We derive the non-perturbative formula of the spin and angular momentum of the partons inside the proton from the first principle in QCD which can be calculated by using the lattice QCD method. PACS numbers: 12.38.-t, 11.30.-j, 14.20.Dh, 12.38.Gc arXiv:1906.03974v1 [physics.gen-ph] 3 Jun 2019 ∗E-Mail: [email protected] Typeset by REVTEX 1 I. INTRODUCTION 1 The spin of the proton is 2 . Since the proton consists of quarks and gluons it was expected 1 that the spin of the quarks and gluons inside the proton add up to give spin 2 of the proton. The proton in motion high energy consists of quarks, antiquarks and gluons because sea quark-antiquark pairs and gluons are produced from the QCD vacuum at high energy. 1 For the proton in motion along z-axis the spin/helicity 2 was expected to be 1 =< p,s|Sˆz|p,s > + < p,s|Sˆz|p,s > (1) 2 q g ˆz where < p,s|Sq |p,s > is the spin of the quarks plus antiquarks inside the proton and ˆz < p,s|Sg |p,s > is the spin of the gluons inside the proton.
    [Show full text]
  • The Proton-Spin Crisis: Another ABJ Anomaly?
    SWAT 98/212 CERN–TH/98–398 The Proton-Spin Crisis: another ABJ anomaly? G.M. Shore Department of Physics, University of Wales Swansea Singleton Park, Swansea, SA2 8PP, U.K. and Theory Division, CERN CH 1211 Geneva 23, Switzerland Contents: 1. Introduction p 2. The First Moment Sum Rule for g1 3. The Parton Model and the ‘Proton Spin’ 4. The CPV Method and Topological Charge Screening 5. Experiment 6. Semi-Inclusive Polarised DIS 1. Introduction For a decade, the ‘proton spin’ problem – the anomalous suppression observed in the flavour singlet component of the first moment of the polarised proton structure function p 2 g1 (x; Q ) – has puzzled and intrigued theorists and experimentalists alike. The consequent research effort has indeed been impressive: to date, the original EMC paper[1] alone has nearly one thousand citations. In this lecture, we first give a brief review of the ‘proton spin’ problem from the standard viewpoint of the parton model. We explain why the 1988 observation by the p EMC of a violation of the Ellis-Jaffe sum rule[2] for g1 was initially mis-interpreted in terms of quark spins and how the problem is resolved in the context of the full QCD parton model[3]. ∗ Lecture presented at the International School of Subnuclear Physics, `From the Planck Length to the Hubble Radius', Erice, 1998. SWAT 98/212 CERN–TH/98–398 December 1998 We then describe an alternative, complementary approach to the description of deep inelastic scattering (DIS), the ‘CPV’ method[4-6], which allows the problem to be viewed in a new light.
    [Show full text]
  • Physics Letters B a Possible Resolution of the Proton Spin Problem
    Physics Letters B 663 (2008) 302–305 Contents lists available at ScienceDirect Physics Letters B www.elsevier.com/locate/physletb A possible resolution of the proton spin problem ∗ F. Myhrer a, , A.W. Thomas b,c a Department of Physics and Astronomy, University of South Carolina, Columbia, SC 29208, USA b Jefferson Lab, 12000 Jefferson Ave., Newport News, VA 23606, USA c College of William and Mary, Williamsburg, VA 23187, USA article info abstract Article history: A number of lines of investigation into the structure of the nucleon have converged to the point where Received 24 September 2007 it seems possible to propose a consistent explanation of the well known proton spin problem. Received in revised form 14 April 2008 © 2008 Elsevier B.V. All rights reserved. Accepted 16 April 2008 Availableonline18April2008 Editor: J.-P. Blaizot There is no more fundamental challenge for strong interaction considerably higher than the initial EMC suggestion. Nevertheless, physics than mapping the distribution of energy, momentum, spin the modern value is still sufficiently small that it constitutes an and angular momentum onto the quarks and gluons that compose on-going “spin problem” of great interest. the nucleon. For the past two decades there has been a tremen- The apparent failure of polarized glue as an explanation for the dous level of activity associated with the latter two, sparked by spin problem leads us to focus again on suggestions made soon af- the discovery, almost 20 years ago, by the European Muon Col- ter the EMC announcement [14–16], which were based on physics laboration (EMC) of a proton “spin crisis” [1].Muchoftheearly that is more familiar to those modeling non-perturbative QCD.
    [Show full text]
  • RHIC Spin--To Study the Spin Structure of the Proton G
    34th SLAC Summer Institute On Particle Physics (SSI 2006), July 17-28, 2006 RHIC Spin--To Study the Spin Structure of the Proton G. Bunce BNL and RBRC, Upton, NY11973, USA The RHIC Spin program, colliding polarized protons at high energy, is about studying the internal structure of the proton. We probe this structure, the polarizations of the quarks and gluons in a polarized proton, using the quarks and gluons of the other colliding proton. With the collider, we achieve high energy where the collisions are understood by perturbative QCD. The program follows a series of important experiments using electrons and muons to probe the proton. These experiments, initiated at SLAC, have shown that the quarks and anti-quarks in the proton carry very little of the proton spin on average, a surprise. RHIC, with its strongly interacting probes, is directly sensitive to the gluons in the proton, and is in the process of measuring the gluon’s contribution to the proton spin. I describe why, how, and what we are learning, and our future program. 1. A HISTORY—FROM QUARKS TO SPIN STRUCTURE A short history of the strong interaction might begin in the mid 1960s, when “quarks” were introduced to begin to understand the zoo of strongly interacting particles that had been discovered from accelerator experiments. The “color” quantum number was needed to describe the Omega^-, a state of three strange quarks, each with the same spin ½ adding to a total spin of 3/2. In the later 1960s, an experiment at SLAC showed that these “quarks” were real.
    [Show full text]