Search for supermassive magnetic monopoles with the MACRO detector at the gran sasso laboratory

We present the results of the search for supermassive magnetic monopoles with the MACRO experiment. Our detector is equipped with three independent subdetectors (liquid scintillation counters, limited streamer tubes and nuclear track detectors), operating in different ranges of monopole velocity. In several years of data taking no candidates were found; the present flux upper limits are the level of half the Parker Bound for β > 10⁻⁴; for 10⁻⁴ < β < 5 × 10⁻² the limit is the best existing.     

Search for magnetic monopoles with the nuclear track detector of the MACRO experiment at gran SASSO

In this paper the limits are presented which were obtained by the search for magnetic monopoles using the MACRO track-etch subdetector as a stand alone detector. We compare the flux upper limit for g = g_D monopoles to other limits obtained by different subdetectors of MACRO, till August 1, 1995, when the construction of the apparatus was completed. The global MACRO monopole limit is compared with other limits from different experiments.     

Detection of magnetic monopoles with the ANTARES detector

The ANTARES Collaboration is constructing a neutrino telescope on the bottom of the Mediterranean Sea. The main goal of ANTARES is to detect high-energy cosmic neutrinos. The detection principle relies on the observation of Čerenkov light emitted by neutrino-induced muons. It is shown that this type of detector is also able to detect exotic particles such as magnetic monopoles. Above the Čerenkov limit, monopoles can be detected because of the emission of large amounts of direct Čerenkov light. Monopoles are also detectable below the Čerenkov limit through the production of δ rays, which in turn emit Čerenkov light. The development of a software trigger for ANTARES designed for monopole detection is presented. A simulation of the δ-ray-induced and direct Čerenkov light emission by monopoles has been made and used to study the trigger efficiency for the detection of monopoles. Techniques to suppress background at the trigger level are presented, and plans for the future are discussed. for the ANTARES Collaboration The text was submitted by the author in English.     

Search for GUT magnetic monopoles and nuclearites with the MACRO experiment

We present the final results obtained by the MACRO experiment in the search for GUT magnetic monopoles and nuclearites. Several searches were performed with different subdetectors, i.e. scintillation counters, limited streamer tubes and nuclear track detectors. No magnetic monopole or nuclearite candidates were found. The MACRO upper limit to the local flux of GUT magnetic monopoles is at the level of 1.4×10⁻¹⁶ cm⁻² s⁻¹ sr⁻¹.     

Search for intermediate mass magnetic monopoles and nuclearites with the SLIM experiment

SLIM is a large area experiment (440 m²) installed at the Chacaltaya cosmic ray laboratory since 2001, and about 100 m² at Koksil, Himalaya, since 2003. It is devoted to the search for intermediate mass magnetic monopoles (10⁷–10¹³ GeV/c²) and nuclearites in the cosmic radiation using stacks of CR-39 and Makrofol nuclear track detectors. In four years of operation it will reach a sensitivity to a flux of about 10^-15 cm^-2 s^-1 sr^-1. We present the results of the calibration of CR-39 and Makrofol and the analysis of a first sample of the exposed detector.     

Search for nucleon decays induced by GUT magnetic monopoles with the MACRO experiment

The interaction of a Grand Unification Magnetic Monopole with a nucleon can lead to a barion-number violating process in which the nucleon decays into a lepton and one or more mesons (catalysis of nucleon decay). In this paper we report an experimental study of the effects of a catalysis process in the MACRO detector. Using a dedicated analysis we obtain new magnetic monopole (MM) flux upper limits at the level of for , based on the search for catalysis events in the MACRO data. We also analyze the dependence of the MM flux limit on the catalysis cross section. Received: 2 August 2002 / Published online: 25 October 2002     

Search for neutrino-produced magnetic monopoles in a bubble chamber exposure

J. Schwinger has suggested that magnetically charged particles could be produced via a magnetically charged intermediate boson process similar to the mechanism sometimes envisioned for double muon production by neutrinos. A search for magnetic monopole production by neutrinos has been made by reexamining the CERN heavy liquid bubble chamber pictures obtained during the neutrino exposures of 1963 and 1967. Five different searches were made for events which contained a free monopole with and without target nucleus excitation, and for bound monopoles which deexcited by photon emission. No events were found. Neutrino monopole production cross-section limits are given.     

Search for magnetic monopoles in proton-antiproton interactions at 540 GeV cm energy

A search for magnetic monopoles hass beenpursued at the proton-antiproton collider at CERN, with plastic detectors. No candidates were found. Limits for the production cross section of such objects are given.     

Search for nuclearites with the SLIM detector

The strange quark matter (SQM) may be the ground state of QCD; nuggets of SQM could be present in cosmic rays (CR). SLIM is a large area experiment, using CR39 and Makrofol track etch detectors, presently deployed at the high altitude CR Laboratory of Chacaltaya, Bolivia. We discuss the expected properties of SQM, from the point of view of its search with SLIM. We present also some preliminary results from SLIM.     

寻找磁单极子

电和磁遍布现代社会方方面面,构成了现有大部分科学技术的基础。因此大家倾向于认为这些效应已经被充分理解,不存在基础物理层面的未解之谜。诚然,在绝大多数应用场合,这些磁电效应可以用James Clerk Maxwell 在1864 年归纳的Maxwell 方程描述。从更深的层次上,这些效应可以从量子电动力学的角度——粒子物理标准模型的一部分,得到自洽解释。该理论工作如此之好以至于它能准确给出电子磁偶极矩的前10 位有效数字。尽管如此,现有电磁学还存在一个我们所不能理解的基础问题——有关磁单极子的问题。     

Colored magnetic monopoles

We extend Dirac's theory of magnetic monopoles to the case of non-Abelian color gauge groups. Exact classical solution is obtained by making use of the gauge-independent method of Yang-Mills field. The case of broken gauge symmetry is also briefly discussed.     

Self-dual magnetic monopoles

The present status of self-dual monopoles is reviewed with a particular attention to a duality conjecture.Invited talk at the International Symposium Selected Topics in Quantum Field Theory and Mathematical Physics, Bechyn, Czechoslovakia, June 14–21, 1981.     

Non-Abelian magnetic monopoles

It is shown that a general, irreducible, SU(n), Sp(n), SO(2n) monopole with maximal symmetry breaking is determined by its spectral data. For SU(n) with minimal symmetry breaking the spectral data is defined and also shown to determine the monopole.Research supported in part by NSF Grant 8120790