Search for magnetic monopoles in the moon
Lunar magnetic monopole charge effects on nearby magnetic field configuration
Schatten, K. H.↗
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Results for “MAGNETIC MONOPOLES”
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Search for magnetic monopoles and stable particles with high electric charges in $\sqrt{s}$ = 13 TeV pp collisions with the ATLAS detector
We present a search for magnetic monopoles and high-electric-charge objects using LHC Run 2 $\sqrt{s}$ = 13 TeV proton-proton collisions recorded by the ATLAS detector. A total integrated luminosity of 138 fb –1 was collected by a specialized trigger. No highly ionizing particle candidate was observed. Considering the Drell-Yan and photon-fusion pair production mechanisms as benchmark models, cross-section upper limits are presented for spin-0 and spin-1/2 magnetic monopoles of magnetic charge 1g D and 2g D and for high-electric-charge objects of electric charge 20 ≤ |z| ≤ 100, for masses between 200 GeV and 4000 GeV. The search improves by approximately a factor of three the previous cross-section limits on the Drell-Yan production of magnetic monopoles and high-electric charge objects. Also, the first ATLAS limits on the photon-fusion pair production mechanism of magnetic monopoles and high-electric-charge objects are obtained.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Boosted Kaluza–Klein magnetic monopole
We consider a Kaluza–Klein vacuum solution which is closely related to the Gross–Perry–Sorkin (GPS) magnetic monopole. The solution can be obtained from the Euclidean Taub–NUT solution with an extra compact fifth spatial dimension within the formalism of Kaluza–Klein reduction. We study its physical properties as appearing in (3+1) spacetime dimensions, which turns out to be a static magnetic monopole. We then boost the GPS magnetic monopole along the extra dimension, and perform the Kaluza–Klein reduction. The resulting four-dimensional spacetime is a rotating stationary system, with both electric and magnetic fields. In fact, after the boost the magnetic monopole turns into a string connected to a dyon.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Search for Magnetic Monopoles with the NO$\nu$A Far Detector
The magnetic monopole is a hypothetical particle, which is an important field configuration in many Grand Unified Theories, and whose mass may vary from 10 4 to 10 18 GeV. The quantization of magnetic charge derived by Dirac in 1931 suggests the heavy ionization nature of magnetic monopoles. The NO$\nu$A collaboration is using the NO$\nu$A far detector - the largest scintillator detector in the world - to search for signals of relic monopoles that might have been produced in the early universe. To achieve this, we have simulated the propagation of non-relativistic monopoles with a uniform distribution of velocity within the range 10 -4 ≲β≲ 0.2 , and the corresponding detector response. To record potential monopole-like events, we have developed a data-driven trigger system with two monopole triggers (the fast monopole trigger and the slow monopole trigger). This analysis focuses on the data recorded by the fast monopole trigger, which is sensitive to monopoles with velocity β ≳ 10 -3 . We have performed a blind analysis on a total live time of 1628.2 hours of data recorded by the fast monopole trigger. We present the updated flux limits with 90% CL (confidence level) as a function of monopole mass and velocity.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Software Trigger Algorithms to Search for Magnetic Monopoles with the NO$\nu$A Far Detector
The NOvA far detector, due to its surface proximity, large size, good timing resolution, large energy dynamic range, and continuous readout, is sensitive to the detection of magnetic monopoles over a large range of velocities and masses. In order to record candidate magnetic monopole events with high efficiency we have designed a software-based trigger to make decisions based on the data recorded by the detector. The decisions must be fast, have high efficiency, and a large rejection factor for the over 100,000 cosmic rays that course through the detector every second. In this paper we briefly describe the simulation of magnetic monopoles, including the detector response, and then discuss the algorithms applied to identify magnetic monopole candidates. We also present the results of trigger efficiency and purity tests using simulated samples of magnetic monopoles with overlaid cosmic backgrounds and electronic noise.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Magnetic Monopoles and Dark Matter
Schwinger’s idea about the magnetic world of the early Universe, in which magnetic charges (monopoles) and magnetic atoms (g{sup +}g{sup –}) could be formed, is developed. In the present-day Universe magnetic charges with energies in the GeV range can be formed in the magnetospheres of young pulsars in superstrong magnetic fields. Spectroscopic features of magnetic atoms and possibilities for their observations are discussed. Relic magnetic atoms can contribute up to 18% to the dark matter density. The gamma-ray excess at our Galactic center could arise under two-photon annihilation of magnetic charges as a cooperative effect from neutron stars. A sharp physical difference of Schwinger’s magnetic world from Dirac’s present-day electric world is pointed out. Artificial magnetic monopoles are also mentioned briefly.
79 ASTRONOMY AND ASTROPHYSICS↗
Searches for relativistic magnetic monopoles in IceCube
Various extensions of the Standard Model motivate the existence of stable magnetic monopoles that could have been created during an early high-energy epoch of the Universe. These primordial magnetic monopoles would be gradually accelerated by cosmic magnetic fields and could reach high velocities that make them visible in Cherenkov detectors such as IceCube. Equivalently to electrically charged particles, magnetic monopoles produce direct and indirect Cherenkov light while traversing through matter at relativistic velocities. This paper describes searches for relativistic ((Formula presented.)) and mildly relativistic ((Formula presented.)) monopoles, each using one year of data taken in 2008/2009 and 2011/2012, respectively. No monopole candidate was detected. For a velocity above (Formula presented.) the monopole flux is constrained down to a level of (Formula presented.). This is an improvement of almost two orders of magnitude over previous limits.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
High pressure route to generate magnetic monopole dimers in spin ice
The gas of magnetic monopoles in spin ice is governed by one key parameter: the monopole chemical potential. A significant variation of this parameter could access hitherto undiscovered magnetic phenomena arising from monopole correlations, as observed in the analogous electrical Coulomb gas, like monopole dimerization, critical phase separation, or charge ordering. However, all known spin ices have values of chemical potential imposed by their structure and chemistry that place them deeply within the weakly correlated regime, where none of these interesting phenomena occur. Here we use high-pressure synthesis to create a new monopole host, Dy 2 Ge 2 O 7 , with a radically altered chemical potential that stabilizes a large fraction of monopole dimers. The system is found to be ideally described by the classic Debye–Huckel–Bjerrum theory of charge correlations. We thus show how to tune the monopole chemical potential in spin ice and how to access the diverse collective properties of magnetic monopoles.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Search for Ultra-relativistic Magnetic Monopoles with the Pierre Auger Observatory
In this paper, we present a search for ultra-relativistic magnetic monopoles with the Pierre Auger Observatory. Such particles, possibly a relic of phase transitions in the early universe, would deposit a large amount of energy along their path through the atmosphere, comparable to that of ultrahigh-energy cosmic rays (UHECRs). The air shower profile of a magnetic monopole can be effectively distinguished by the fluorescence detector from that of standard UHECRs. No candidate was found in the data collected between 2004 and 2012, with an expected background of less than 0.1 event from UHECRs. The corresponding 90% confidence level (C.L.) upper limits on the flux of ultra-relativistic magnetic monopoles range from $10^{-19}$ (cm$^{2}$ sr s)$^{-1}$ for a Lorentz factor $\gamma=10^9$ to $2.5 \times10^{-21}$ (cm$^{2}$ sr s)$^{-1}$ for $\gamma=10^{12}$. Lastly, these results - the first obtained with a UHECR detector - improve previously published limits by up to an order of magnitude.
79 ASTRONOMY AND ASTROPHYSICS↗
Search for magnetic monopoles in lunar material using an electromagnetic detector.
Our search for magnetic monopoles in lunar materials has been concluded with the exploration of an additional 11.5 kg of material returned by the Apollo 11, 12, and 14 missions, using a modified version of our electromagnetic detector. Again, no magnetic monopole was detected. Combining these results with the results of our previous experiment, we set an upper limit of .00017 monopoles/g for the density of isolated monopoles in the lunar surface and improve our upper limits set for the monopole flux in cosmic rays and for monopole pair-production cross section.
Ross, R. R.↗
Search for magnetic monopoles in lunar material.
A search for magnetic monopoles in lunar material has been performed by the electromagnetic measurement of the magnetic charge of samples. All measurements were found consistent with zero charge for all samples and inconsistent with any other value allowed by the Dirac theory. Upper limits are determined for the monopole flux in cosmic radiation and for the pair-production cross section in proton-nucleon collisions.
Eberhard, P. H.↗
Magnetic monopoles and free fractionally charged states at accelerators and in cosmic rays
Unified theories of strong, weak and electromagnetic interactions which have electric charge quantization predict the existence of topologically stable magnetic monopoles. Intermediate scale monopoles are comparable with detection energies of cosmic ray monopoles at IceCube and other cosmic ray experiments. Magnetic monopoles in some models can be significantly lighter and carry two, three or possibly even higher quanta of the Dirac magnetic charge. They could be light enough for their effects to be detected at the LHC either directly or indirectly. An example based on a D-brane inspired SU(3) C × SU(3) L × SU(3) R (trinification) model with the monopole carrying three quanta of Dirac magnetic charge is presented. These theories also predict the existence of color singlet states with fractional electric charge which may be accessible at the LHC.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Search for magnetic monopoles in s = 7 TeV p p collisions with the ATLAS detector
CERN-LHC. Search for magnetic monopoles in proton-proton collisions at a centre-of-mass energy of 7 TeV using data with a total integrated luminosity of 2.0 fb-1. Magnetic monopoles are characterized by large localized energy deposits in the LAr EM calorimeter (EMCLUSTER) in conjunction with a region of high ionization density in the transition radiation tracker, TRT. This record lists the efficiency for detection of such monopoles of two masses (200 and 1500 GeV) and the upper limits of the cross sections assuming production by Drell-Yan processes and in the fiducual region.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Equilibrium field theory of magnetic monopoles in degenerate square spin ice: Correlations, entropic interactions, and charge screening regimes
In this work, we describe degenerate square spin as an ensemble of magnetic monopoles coupled via an emergent entropic field that subsumes the effect of the underlying spin vacuum. We compute their effective free energy, entropic interaction, correlations, screening, and structure factor, and find that they coincide with the experimental ones. Unlike in pyrochlore ices, a dimensional mismatch between real and entropic interactions leads to weak singularities at the pinch points and algebraic correlations at long distances. This algebraic screening can be, however, camouflaged by a pseudoscreening regime.
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
Search for magnetic monopoles in the lunar samples of Apollo 11
Magnetic monopoles electromagnetic search in Apollo 11 rock samples
Alvarez, L. W.↗
Extension of the Parker bound on the flux of magnetic monopoles
The Parker bound on the flux of magnetic monopoles is extended and strengthened. A new limit on the survival and growth of a small galactic seed field is obtained which rules out the possibility that monopoles much lighter than 10 exp 17 GeV/sq c can provide the closure density of the universe.
Adams, Fred C.↗
Realizations of magnetic-monopole gauge fields - Diatoms and spin precession
It is found that the effective Hamiltonian for nuclear rotation in a diatom is equivalent to that of a charged particle in a background magnetic-monopole field. In certain cases, half-integer orbital angular momentum or non-Abelian fields occur. Furthermore, the effects of magnetic-monopole-like gauge fields can be experimentally observed in spin-resonance experiments with variable magnetic fields.
Moody, J.↗
Ionization-based search for magnetic monopoles using the NOvA Far Detector
We report a search for highly ionizing magnetic monopoles in the cosmic-ray flux using a 2713-day dataset collected during 2015–2025 with the NOvA Far Detector, a 14-kt segmented detector located on Earth’s surface in Minnesota, United States. The search is sensitive to monopoles across a wide range of speeds, 7 × 10 −4 < 𝛽 < 0.995, and is sensitive to masses as low as 2 × 10 5 GeV for the fastest monopoles. No signal was observed. With the detector’s large surface area and minimal overburden, we achieve the strongest flux limits reported to date in several regions of speed and mass. For heavy monopoles with masses above 10 13 GeV that are able to reach the detector from above or—crossing Earth—from below, we find a flux limit 𝜙 90% < 2 × 10 −16 cm −2 s −1 sr −1 (90% confidence level) for monopoles with 0.005 < 𝛽 < 0.8. Across the same range of speeds, we report a limit 𝜙 90% < 8 × 10 −16 cm −2 s −1 sr −1 for light monopoles with masses above 10 8 GeV that can reach the detector from above.
magnetic monopoles↗