Production Of Magnetic Monopoles Research Articles

Search for magnetic monopoles and stable particles with high electric charges in s\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\sqrt{s} $$\\end{document} = 13 TeV pp collisions with the ATLAS detector

We present a search for magnetic monopoles and high-electric-charge objects using LHC Run 2 s\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\sqrt{s} $$\\end{document} = 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 1gD and 2gD 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.

Shining light on magnetic monopoles through high-energy muon colliders

The search for magnetic monopoles has been a longstanding concern of the physics community for nearly a century. However, up to now, the existence of elementary magnetic monopoles remains an open question. The electroweak 't Hooft-Polyakov monopoles have been predicted with mass at the order of 10 TeV. This mass scale is unreachable at current colliders. Recently, the muon colliders have gained much attention in the community due to technological developments. The advantages of the muon beam encourage us to raise the high-energy option and consider the high-energy muon collider as a unique opportunity to search for magnetic monopoles. This letter discusses the production of magnetic monopoles via the annihilation process and proposes the search for magnetic monopoles at future high-energy muon colliders.

Search for highly-ionizing particles in pp collisions at the LHC’s Run-1 using the prototype MoEDAL detector

A search for highly electrically charged objects (HECOs) and magnetic monopoles is presented using 2.2 hbox {fb}{^{-1}} of p-p collision data taken at a centre of mass energy (E_{CM}) of 8 TeV by the MoEDAL detector during LHC’s Run-1. The data were collected using MoEDAL’s prototype Nuclear Track Detectord array and the Trapping Detector array. The results are interpreted in terms of Drell–Yan pair production of stable HECO and monopole pairs with three spin hypotheses (0, 1/2 and 1). The search provides constraints on the direct production of magnetic monopoles carrying one to four Dirac magnetic charges and with mass limits ranging from 590 GeV/c^{2} to 1 TeV/c^{2}. Additionally, mass limits are placed on HECOs with charge in the range 10e to 180e, where e is the charge of an electron, for masses between 30 GeV/c^{2} and 1 TeV/c^{2}.

Monopoles from an Atmospheric Fixed Target Experiment.

Magnetic monopoles have a long history of theoretical predictions and experimental searches, carrying direct implications for fundamental concepts such as electric charge quantization. We analyze in detail for the first time magnetic monopole production from collisions of cosmic rays bombarding the atmosphere. This source of monopoles is independent of cosmology, has been active throughout Earth's history, and supplies an irreducible monopole flux for all terrestrial experiments. Using results for robust atmospheric fixed target experiment flux of monopoles, we systematically establish direct comparisons of previous ambient monopole searches with monopole searches at particle colliders and set leading limits on magnetic monopole production in the ∼5-100 TeV mass range.

Pair production of magnetic monopoles and stable high-electric-charge objects in proton–proton and heavy-ion collisions

We describe pair-production models of spin-0 and spin-½ magnetic monopoles and high-electric-charge objects (HECOs) in proton–proton (pp) and heavy-ion collisions, considering both the Drell–Yan (DY) and the photon-fusion processes. In particular, we extend the DY production model of spin-½ HECOs to include Z 0-boson exchange for pp collisions. Furthermore, we explore spin-½ and, for the first time, spin-0 production in ultraperipheral heavy-ion collisions. With matrix element calculations and equivalent photon fluxes implemented in MadGraph5_aMC@NLO, we present leading-order production cross sections of these mechanisms in TeV pp collisions and TeV ultraperipheral lead–lead collisions at the LHC. While the mass range accessible in ultraperipheral lead–lead collisions is much lower than that in pp collisions, we find that the theoretical production cross sections are significantly enhanced in the former for masses below 82 GeV.

Search for Magnetic Monopoles and Stable High-Electric-Charge Objects in 13Tev Proton-Proton Collisions with the ATLAS Detector.

A search for magnetic monopoles and high-electric-charge objects is presented using 34.4 fb^{-1} of 13TeV pp collision data collected by the ATLAS detector at the LHC during 2015 and 2016. The considered signature is based upon high ionization in the transition radiation tracker of the inner detector associated with a pencil-shape energy deposit in the electromagnetic calorimeter. The data were collected by a dedicated trigger based on the tracker high-threshold hit capability. The results are interpreted in models of Drell-Yan pair production of stable particles with two spin hypotheses (0 and 1/2) and masses ranging from 200 to 4000GeV. The search improves by approximately a factor of 5 the constraints on the direct production of magnetic monopoles carrying one or two Dirac magnetic charges and stable objects with electric charge in the range 20≤|z|≤60 and extends the charge range to 60<|z|≤100.

Towards Schwinger production of magnetic monopoles in heavy-ion collisions

Magnetic monopoles may be produced by the Schwinger effect in the strong magnetic fields of peripheral heavy-ion collisions. We review the form of the electromagnetic fields in such collisions and calculate from first principles the cross section for monopole pair production. Using the worldline instanton method, we work to all orders in the magnetic charge, and hence are not hampered by the breakdown of perturbation theory. Our result depends on the spacetime inhomogeneity through a single dimensionless parameter, the Keldysh parameter, which is independent of collision energy for a given monopole mass. For realistic heavy-ion collisions, the computational cost of the calculation becomes prohibitive and the finite size of the monopoles needs to be taken into account, and therefore our current results are not applicable to them. Nonetheless, our results show that the spacetime dependence enhances the production cross section and would therefore lead to stronger monopole mass bounds than in the constant-field case.

The MoEDAL Experiment at the LHC - Searching for Physics Beyond the Standard Model

MoEDAL is a pioneering experiment designed to search for highly ionizing messengers of new physics such as magnetic monopoles or massive (pseudo-)stable charged particles, that are predicted to exist in a plethora of models beyond the Standard Model. It started data taking at the LHC at a centre-of-mass energy of 13 TeV, in 2015. MoEDAL’s ground breaking physics program defines a number of scenarios that yield potentially revolutionary insights into such foundational questions as: are there extra dimensions or new symmetries; what is the mechanism for the generation of mass; does magnetic charge exist; and what is the nature of dark matter. MoEDAL’s purpose is to meet such far-reaching challenges at the frontier of the field. We will present an overview of the MoEDAL detector, including the planned MAPP subdetector, as well as MoEDAL’s physics program. The concluding section highlights our first physics results on Magnetic Monopole production, that are the world’s best for Monopoles with multiple magnetic charge.

Magnetic Monopole Mass Bounds from Heavy-Ion Collisions and Neutron Stars.

Magnetic monopoles, if they exist, would be produced amply in strong magnetic fields and high temperatures via the thermal Schwinger process. Such circumstances arise in heavy-ion collisions and in neutron stars, both of which imply lower bounds on the mass of possible magnetic monopoles. In showing this, we construct the cross section for pair production of magnetic monopoles in heavy-ion collisions, which indicates that they are particularly promising for experimental searches such as MoEDAL.

Production of magnetic monopoles and monopolium in peripheral collisions

The exclusive production by the photon fusion of magnetic monopoles and the bound states of magnetic monopoles, the monopolium, is consider in different high energy processes. More specifically, we calculate the total cross sections of the ultraperipheral elastic collisions of electron-electron, proton-proton and lead-lead in present and future colliders, comparing with the previous results found in the literature. Our results indicates that magnetic monopoles or his bound states, if both exists, can be measuareble in future electron-electron colliders.

Search for Magnetic Monopoles with the MoEDAL Forward Trapping Detector in 13TeV Proton-Proton Collisions at the LHC.

MoEDAL is designed to identify new physics in the form of long-lived highly ionizing particles produced in high-energy LHC collisions. Its arrays of plastic nuclear-track detectors and aluminium trapping volumes provide two independent passive detection techniques. We present here the results of a first search for magnetic monopole production in 13TeV proton-proton collisions using the trapping technique, extending a previous publication with 8TeV data during LHC Run 1. A total of 222kg of MoEDAL trapping detector samples was exposed in the forward region and analyzed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges exceeding half the Dirac charge are excluded in all samples and limits are placed for the first time on the production of magnetic monopoles in 13TeV pp collisions. The search probes mass ranges previously inaccessible to collider experiments for up to five times the Dirac charge.

Soliton creation with a twist

We consider soliton creation when there are ``twist'' degrees of freedom present in the model in addition to those that make up the soliton. Specifically, we consider a deformed O(3) sigma model in $1+1$ dimensions, which reduces to the sine-Gordon model in the zero twist sector. We study the scattering of two or more breather solutions as a function of twist, and find soliton creation for a range of parameters. We speculate on the application of these ideas, in particular, on the possible role of magnetic helicity, to the production of magnetic monopoles, and the violation of baryon number in nuclear scattering experiments.

Dirac magnetic monopole production from photon fusion in proton collisions

We calculate the lowest order cross--section for Dirac magnetic monopole production from photon fusion in p p-bar collisions at sqrt{s}=1.96 TeV, p p collisions at sqrt{s}=14 TeV, and we compare photon fusion with Drell--Yan (DY) production. We find the total photon fusion cross--section is comparable with DY at sqrt{s}=1.96 TeV and dominates DY by a factor ~50 at sqrt{s}=14 TeV. We conclude that both the photon fusion and DY processes allow for a monopole mass limit m>370 GeV based upon the null results of the recent monopole search at the Collider Detector at Fermilab (CDF). We also conclude that photon fusion is the leading production mechanism to be considered for direct monopole searches at the Large Hadron Collider (LHC).

ON PRODUCTION OF MAGNETIC MONOPOLES VIA γγ FUSION AT HIGH ENERGY pp COLLISIONS

We consider the production of magnetic monopoles via γγ fusion at high energy pp collisions. In the assumption that the monopole spin is equal 0, 1/2, 1, the monopole–antimonopole pair production cross-section by this mechanism at LHC energies is estimated and analyzed.

Limits on production of magnetic monopoles utilizing samples from the D0 and CDF detectors at the Fermilab Tevatron

We present 90% confidence level limits on magnetic monopole production at the Fermilab Tevatron from three sets of samples obtained from the D0 and CDF detectors each exposed to a proton-antiproton luminosity of $\ensuremath{\sim}175{\mathrm{pb}}^{\ensuremath{-}1}$ (experiment E-882). Limits are obtained for the production cross sections and masses for low-mass accelerator-produced pointlike Dirac monopoles trapped and bound in material surrounding the D0 and CDF collision regions. In the absence of a complete quantum field theory of magnetic charge, we estimate these limits on the basis of a Drell-Yan model. These results (for magnetic charge values of 1, 2, 3, and 6 times the minimum Dirac charge) extend and improve previously published bounds.

New shifted hybrid inflation

A new shifted hybrid inflationary scenario is introduced which, in contrast to the older one, relies only on renormalizable superpotential terms. This scenario is automatically realized in a concrete extension of the "minimal" supersymmetric Pati-Salam model which naturally leads to a moderate violation of Yukawa unification so that, for mu>0, the predicted b-quark mass is acceptable even with universal boundary conditions. It is shown that this extended model possesses a classically flat "shifted" trajectory which acquires a slope via one-loop radiative corrections and can be used as inflationary path. The constraints from the cosmic background explorer can be met with natural values of the relevant parameters. Also, there is no disastrous production of magnetic monopoles after inflation since the Pati-Salam gauge group is already broken on the "shifted" path. The relevant part of inflation takes place at values of the inflaton field which are not much smaller than the "reduced" Planck scale and, thus, supergravity corrections could easily invalidate inflation. It is, however, shown that inflation can be kept intact provided that an extra gauge singlet with a superheavy vacuum expectation value, which originates from D-terms, is introduced and a specific form of the Kaehler potential is used. Moreover, it is found that, although the supergravity corrections are sizable, the constraints from the cosmic background explorer can again be met by readjusting the values of the parameters which were obtained with global supersymmetry.

On the primordial monopole problem in grand unified theories

It is shown that spontaneously broken gauge symmetries are not necessarily restored at very high temperatures, in which case an unacceptably large production of magnetic monopoles may be prohibited.

Thermal production of superheavy magnetic monopoles in the early universe

Starting with an initial abundance of zero, we calculate the thermal production of magnetic monopoles by using the monopole-antimonopole annihilation cross section and detailed balance. The final abundance of monopoles depends exponentially upon m/ T i ; m is the monopole mass ∼10 16 GeV and T i is the temperature when production commences. For m/ T i ≈35–55 the present monopole to photon ratio is nM/ n γ ≈10 −23−10 −38, less than the bound derived from the present mass density, but possibly large enough to be detected. This calculation provides a lower bound on the monopole abundance for a given m/ T i .

On a cosmological aspect of the phase transition at the grand unification temperature

The phase transition at the temperature of grand unification is studied in the curved space-time of a Friedmann universe, using the minimal SU(5) model of Georgi and Glashow. As a result of the changes induced in the scalar field ϕ by the cosmological expansion, a kinetic energy term appears in the phase with broken symmetry, for which 〈0|ϕ|0〉 is non-zero. An estimate of the importance of this hitherto neglected cosmological kinetic term is obtained by calculation from the flat-space solution elaborated by Daniel and Vayonakis. When there is very little supercooling, and for certain values of the constants in the theory, and if the X-boson mass m X is of order 3 × 10 15 GeV, then this kinetic energy has about the same magnitude as the effective potential at the temperature T 1, corresponding to the limit of metastability of the symmetric phase. At higher temperatures and for higher values of m X, the kinetic energy can be dominant. At lower temperatures, and when there is much supercooling, then it is negligible. The significance of this result is discussed, including its consequences for theories, such as have sometimes been proposed, which demand a high value for m X, and for the “superconducting” universe of Mohapatra and Senjanović. The mechanism for the suppression of the production of magnetic monopoles suggested by Bais and Rudaz is re-examined. Their key assumption that the phase transition is only weakly of first order is shown not to hold for the range of parameters which they use. But the contention of Linde that the transition is always strongly of first order is also found not to be true. The theory can be designed so that the phase transition is weakly of first order. Then, the effect of the kinetic energy may be significant, but will not be large enough to make the model of Bais and Rudaz viable.

Monopole production in the very early universe in a first-order phase transition

The implications for magnetic monopole production of a first-order phase transition in the evolution of the early universe are discussed. Because of cosmological limits on the monopole density, strong constraints on the properties of the phase transition are required. The universe is likely to supercool, with the phase transition terminating either because the metastable state becomes unstable or because the universe is filled by “bubbles” of the broken symmetry state. Both scenarios are complicated by the exponential expansion of the supercooled universe, owing to the large cosmological term existing before the phase transition. To achieve the required dilution of the monopole/entropy ratio in either case would require a fortuitous arrangement of the parameters of the grand unified theory. We also comment on the implications of a first-order phase transition for the generation of a baryon excess. In the appendix, we elaborate a conjecture concerning the theory of nucleation in finite-temperature quantum field theory.