Magnetic monopoles (MMs) are well-motivated hypothetical particles whose discovery would symmetrize Maxwell equations, explain quantization of electric charge, and probe the gauge structure of the unified theory. Recent models predict MMs with low masses, reinvigorating searches at colliders. However, most theories predict composite MMs, whose production in parton-parton collisions is expected to be suppressed. The Schwinger process, whereby MM pairs tunnel through the vacuum barrier in the presence of a strong magnetic field, is not subject to this limitation. Additionally, the Schwinger cross section can be calculated nonperturbatively. Together, these make it a golden channel for low-mass MM searches. We investigate the Schwinger production of MMs in heavy-ion collisions at future colliders, in collisions of cosmic rays with the atmosphere, and in decay of magnetic fields of cosmic origin. We find that a next-generation collider would provide the best sensitivity, allowing one to discover or exclude MMs with TeV-scale masses. At the same time, exploiting the infrastructure of industrial ore extraction and Antarctic ice drilling could advance the field at a faster timescale and with only a modest investment. In particular, we show with detailed calculations that the proposed experiments will be sensitive to fluxes of low-mass MMs as low as a few units of 10^{-22} cm^{-2} s^{-1} sr^{-1} in a wide range of Lorentz factors. We also propose deploying dedicated MM detectors in conjunction with cosmic ray observatories to directly investigate if the unexplained, highest energy cosmic rays are MMs. Together, the proposed efforts would define the field of MM searches in the next decades.
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 …
In this review, we discuss recent developments in both the theory and the experimental searches of magnetic monopoles in past, current and future colliders and in the Cosmos. The theoretical models include, apart from the standard Grand Unified Theories, extensions of the Standard Model that admit magnetic monopole solutions with finite energy and masses that can be as light as a few TeV. Specifically, we discuss, among other scenarios, modified Cho-Maison monopoles and magnetic monopoles in (string-inspired, higher derivative) Born-Infeld extensions of the hypercharge sector of the Standard M…
Recently, there have been proposals that the classic Euler-Heisenberg Lagrangian together with duality could be employed to set limits on magnetic monopoles having masses less than 1 TeV. The D0 collaboration at Fermilab has used such a proposal to set mass limits based on the nonobservation of pairs of photons each with high transverse momentum. In this note, we critique the underlying theory, by showing that at the quoted limits the cross section violates unitarity and is unstable with respect to radiative corrections. It is proposed that the correct coupling of magnetic monopoles to photons…
This topical group focuses on searches for signals from physics Beyond the Standard Model (BSM), both from a theoretical and experimental perspective, including neutrino-related BSM and searches for BSM in other sectors using neutrino facilities.
We identify a previously untapped discovery channel for grand-unification monopoles, arising from their ability to catalyse the direct decay of protons into monoenergetic 459 MeV antineutrinos within the Sun. Previous analyses omit this possibility as it necessarily involves an electroweak suppression factor, and instead search for the unsuppressed 20-50 MeV neutrinos produced via two-stage proton decays. By accounting for the relative difference in interaction cross section and experimental background at typical neutrino detection experiments, we demonstrate that this new channel in fact poss…
The exclusive decay mode B ->K*ll has become one of the key players in the search for New Physics in flavor. An increasing number of observables are being studied experimentally, and with increasing precision. Its theoretical description is well under control, and an interesting set of clean observables have been identified, reducing further the theoretical uncertainties. Model-independent analyses show that in the near future this mode will either reveal NP through a pattern of correlated deviations from the SM, or pose very stringent constraints on radiative and semileptonic operators.
Proton decay, and the decay of nucleons in general, constitutes one of the most sensitive probes of high-scale physics beyond the Standard Model. Most of the existing nucleon decay searches have focused primarily on two-body decay channels, motivated by Grand Unified Theories and supersymmetry. However, many higher-dimensional operators violating baryon number by one unit, $ΔB = 1$, induce multi-body nucleon decay channels, which have been only weakly constrained thus far. While direct searches for all such possible channels are desirable, they are highly impractical. In light of this, we argu…
Hidden monopole is a plausible dark matter candidate due to its stability, but its direct experimental search is extremely difficult due to feeble interactions with the standard model particles in the minimal form. Then, we introduce an axion, $a$, connecting the hidden monopole and the standard model particles and examine the current limits and future prospects of direct dark matter searches and beam-dump experiments. We find two parameter regions around $m_a = {\cal O}(10)$ MeV, $f_a = {\cal O}(10^{5})$ GeV and $m_a = {\cal O}(100)$ MeV, $f_a = {\cal O}(10^{4})$ GeV where monopole dark matte…
The Standard Model (SM) of the microcosm provides an excellent description of the phenomena of the microcosm, with the triumph of the discovery of the Higgs boson. There are many reasons, however, to believe that the SM is incomplete and represents a valid theory at relatively low energies only. Of particular interest are the models based on complete symmetries, such as those attempting a true unification between leptons and quarks in terms of a single symmetry group (Grand Unified Theories, GUTs) and those attempting unification between fermions and bosons, such as the supersymmetry. This cha…
Recently, there has been renewed interest in the search for low-mass magnetic monopoles. At the University of Oklahoma we are performing an experiment (Fermilab E882) using material from the old D0 and CDF detectors to set limits on the existence of Dirac monopoles of masses of the order of 500 GeV. To set such limits, estimates must be made of the production rate of such monopoles at the Tevatron collider, and of the binding strength of any such produced monopoles to matter. Here we sketch the still primitive theory of such interactions, and indicate why we believe a credible limit may still …
Run 2 at the Tevatron started in spring 2001. CDF and D0 are taking data at a center-of-mass energy of 1.96 TeV. First results on searches for phenomena beyond the Standard Model are presented. In January 2003, the integrated luminosity recorded per experiment was lower than the luminosity collected at Run 1. Nevertheless, these results are already competitive due to improved detector capabilities and to the increase in the center-of-mass energy.
Intriguing signals with excesses over expected backgrounds have been observed in many astrophysical and terrestrial settings, which could potentially have a dark matter origin. Astrophysical excesses include the Galactic Center GeV gamma-ray excess detected by the Fermi Gamma-Ray Space Telescope, the AMS antiproton and positron excesses, and the 511 and 3.5 keV X-ray lines. Direct detection excesses include the DAMA/LIBRA annual modulation signal, the XENON1T excess, and low-threshold excesses in solid state detectors. We discuss avenues to resolve these excesses, with actions the field can ta…
The LHC lifetime frontier will probe dark sector in near future, and the visible decay searches at fixed-target experiments have been exploring dark sector. Composite asymmetric dark matter with dark photon portal is a promising framework explaining the coincidence problem between dark matter and visible matter. Dark strong dynamics provides rich structure in the dark sector: the lightest dark nucleon is the dark matter, while strong annihilation into dark pions depletes the symmetric components of the dark matter. Dark photons alleviate cosmological problems. Meanwhile, dark photons make dark…
The existence of magnetic monopoles, also predicted in some GUT theories, would symmetrise Maxwell equations and explain the charge quantisation. Searches for them are being performed in cosmic telescopes as well as in collider experiments, such as MoEDAL and ATLAS. In this report, we focus on the, least explored, photon-fusion mechanism, yet Drell-Yan results are discussed, too. Cross sections for monopoles of spin 0, 1/2 and 1 for an effective monopole-velocity-dependent magnetic charge are presented. For spin-1/2 and spin-1 monopoles, a magnetic-moment term is included, which is treated as …
This is the Snowmass 2021 Rare and Precision Frontier Report. The Rare Processes and Precision Measurements Frontier, referred to as the ``Rare and Precision Frontier", or RPF, encompasses searches for extremely rare processes or tiny deviations from the Standard Model (SM) that can be studied with intense sources and high-precision detectors. Our community studies have identified several unique research opportunities that may pin down the scales associated with New Physics (NP) interactions and constrain the couplings of possible new degrees of freedom. Searches for rare flavor transition pro…
In this work we consider point-like monopole production via photon-fusion and Drell-Yan processes in the framework of an effective U(1) gauge field theory obtained from conventional models describing the interaction of spin 0, 1/2, 1 magnetically-charged fields with ordinary photons, upon electric-magnetic dualisation. We present arguments based on such dualities which support the conjecture of an effective monopole-velocity-dependent magnetic charge. For the cases of spin-1/2 and spin-1 monopoles, we also include a magnetic-moment term kappa, which is treated as a new phenomenological paramet…
We discuss ways to probe the origin of neutrino masses at the Energy and Intensity frontiers, in TeV-scale left-right seesaw models where small neutrino masses arise via type-I seesaw mechanism. We consider generic ('vanilla') version of such models as well as a version which leads to 'large' light-heavy neutrino mixing while keeping the neutrino masses small in a natural manner. We point out specific observable implications of these classes of models at the LHC as well as in searches for lepton flavor violating processes such as $μ\to eγ$ and $μ\to 3e$, and also in searches for lepton number …
We assess the current coverage and the future discovery potential of LHC searches for heavy Higgs bosons decaying into long-lived particles (LLPs), focusing primarily on the production of pairs of LLPs with hadronic final states. These signatures are generic in dark sectors where a heavy scalar decays into pairs of lighter states which subsequently mix with the Standard Model Higgs. We show that a handful of existing analyses provide broad coverage of LLP decay lengths ranging from millimeters to tens of meters, and explore the complementarity between searches for displaced and prompt final st…
Plots summarizing the constraints on Dark Matter models can help visualize synergies between different searches for the same kind of experiment, as well as between different experiments. In this whitepaper, we present an update to the European Strategy Briefing Book plots, from the perspective of collider searches within the Dark Matter at the Energy Frontier (EF10) Snowmass Topical Group, starting from inputs from future collider facilities. We take as a starting point the plots currently made for LHC searches using benchmark models recommended by the Dark Matter Working Group, also used for …
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.
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…
This whitepaper focuses on the astrophysical systematics which are encountered in dark matter searches. Oftentimes in indirect and also in direct dark matter searches, astrophysical systematics are a major limiting factor to sensitivity to dark matter. Just as there are many forms of dark matter searches, there are many forms of backgrounds. We attempt to cover the major systematics arising in dark matter searches using photons -- radio and gamma rays -- to cosmic rays, neutrinos and gravitational waves. Examples include astrophysical sources of cosmic messengers and their interactions which c…
We study the scenarios where a strongly first-order electroweak phase transition (EWPT) is triggered by a light singlet scalar, which has feeble interactions to the Higgs. Since the singlet scalar is light and has weak couplings, it can decay at a macroscopic distance away from the collision point. Therefore, it can be regarded as a long-lived particles (LLP) in such scenarios. We perform the searches of the LLPs from the exotic Higgs decays, at the FASER, MAPP and CMS-Timing detectors of the 14 TeV HL-LHC, to probe the strongly first-order EWPT. In certain scenarios, we show that the LLP sear…
Magnetic monopoles may be produced by the dual Schwinger effect in strong magnetic fields. Today, the strongest known magnetic fields in the universe are produced fleetingly in heavy-ion collisions. We use the complex worldline instanton method to calculate the momentum distribution of magnetic monopoles produced in heavy-ion collisions, in an approximation that includes the effect of the magnetic field to all orders but neglects monopole self-interactions. The result saturates the preparation time-energy uncertainty principle, and yields a necessary ingredient for experimental monopole search…
Numerous and all unsuccessful attempts of experimental search for monopole in cosmic rays and on accelerators in high energy particle collisions have been done since the possibility of existence of a magnetic monopole has been surveyed in 1931. Also the searches have been carried out in mica for monopole tracks as well as for relict monopoles, entrapped by ferromagnetic inclusions in iron-ores, moon rock and meteorites. A new method of search for supermassive cosmic and relict monopoles by magnetically ordered film is considered. This approach resembles the traditional method of nuclear emulsi…
One of the most basic properties of magnetism is that a magnet always has two poles, north and south, which cannot be separated into isolated poles, i.e., magnetic monopoles. However, there are strong theoretical arguments why magnetic monopoles should exist. In spite of extensive searches they have not been found, but they have nevertheless played a central role in our understanding of physics at the most fundamental level.
We study the intersection of flavour and collider physics for Two-Higgs-Doublet models of Type I and II. Drawing from the flavour precision-LHC exotics search complementarity, we also provide a projection of the future sensitivity that can be achieved in light of currently available analyses. On the one hand, we find that the parameter space of the 2HDM can be explored significantly further with more data from the LHC with some complementarity with flavour physics. On the other hand, flavour physics results alongside their projections remain powerful tools to constrain the model space in regio…
We present new bounds on the cosmic abundance of magnetic monopoles based on the survival of primordial magnetic fields during the reheating and radiation-dominated epochs. The new bounds can be stronger than the conventional Parker bound from galactic magnetic fields, as well as bounds from direct searches. We also apply our bounds to monopoles produced by the primordial magnetic fields themselves through the Schwinger effect, and derive additional conditions for the survival of the primordial fields.
Single-photon atom gradiometry is a powerful experimental technique that can be employed to search for the oscillation of atomic transition energies induced by ultralight scalar dark matter (ULDM). In the sub-Hz regime the background is expected to be dominated by gravity gradient noise (GGN), which arises as a result of mass fluctuations around the experiment. In this work we model the GGN as surface Rayleigh waves, and we construct a likelihood-based analysis that consistently folds GGN into the sensitivity estimates of vertical atom gradiometers in the frequency window between 1 mHz and 1 H…
We consider scalar extensions of the SM and their effective field theoretic generalisations to illustrate the phenomenological connection between precision measurements of the anomalous magnetic moment of the muon $a_μ$, precision Higgs measurements, and direct collider sensitivity. To this end, we consider charged BSM scalar sectors of the Zee-Babu type for which we develop a consistent, and complete dimensions-5 and -6 effective field theory extension. This enables us to track generic new physics effects that interact with the SM predominantly via radiative interactions. While the operator s…
We discuss how the intensity and the energy frontiers provide complementary constraints within a minimal model of neutrino mass involving just one new field beyond the Standard Model at accessible energy, namely a doubly charged scalar $S^{++}$ and its antiparticle $S^{--}$. In particular we focus on the complementarity between high-energy LHC searches and low-energy probes such as lepton flavor violation. Our setting is a prime example of how high- and low-energy physics can cross-fertilize each other.
No systematic procedure currently exists for inferring the underlying physics from discrepancies observed in high energy collider data. We present Bard, an algorithm designed to facilitate the process of model construction at the energy frontier. Top-down scans of model parameter space are discarded in favor of bottom-up diagrammatic explanations of particular discrepancies, an explanation space that can be exhaustively searched and conveniently tested with existing analysis tools.
This paper explores the physics reach of the proton-proton Future Circular Collider (FCC-hh) and of the High-Energy LHC (HE-LHC) for searches of new particles produced in the $s$-channel and decaying to two high-energy leptons, jets (non-tops), tops or W/Z bosons. We discuss the expected discovery potential and exclusion limits for benchmark models predicting new massive particles that result in resonant structures in the invariant mass spectrum. We also present a detailed study of the HE-LHC potential to discriminate among different models, for a $Z'$ that could be discovered by the end of Hi…
Low-Mass Magnetic Monopoles in the Galaxy: Simulations and Comparison with Ultra-High-Energy Cosmic-Ray Data
Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）；Institute of Theoretical Physics, Faculty of Physics, University of Warsaw（华沙大学物理学院理论物理研究所）
MoEDAL is a pioneering experiment designed to search for highly ionising 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. Its 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, what is the nature of dark matter, and, how did the big-bang develop at the …
This review summarizes the state of the art in searches for supersymmetry at colliders on the eve of the LHC era. Supersymmetry is unique among extensions of the standard model in being motivated by naturalness, dark matter, and force unification, both with and without gravity. At the same time, weak-scale supersymmetry encompasses a wide range of experimental signals that are also found in many other frameworks. We recall the motivations for supersymmetry and review the various models and their distinctive features. We then comprehensively summarize searches for neutral and charged Higgs boso…
Magnetic monopoles have attracted the attention of physicists since the founding of the electromagnetic theory. Their search has been a constant endeavor which was intensified when Dirac established the relation between the existence of monopoles and charge quantization. However, these searches have been unsuccessful. We have recently proposed that monopolium, a monopole-antimonopole bound state, so strongly bound that it has a relatively small mass, could be easier to find and become an indirect but clear signature for the existence of magnetic monopoles. In here we extend our previous analys…
We study constraints on Left-Right Symmetric models from searches of semileptonic decays of $D$, $D_{s}$, $B$ mesons, mediated by heavy neutrinos $N$ with masses $m_N\sim $ GeV that go on their mass shell leading to a resonant enhancement of the rates. Using these processes we examine, as a function of $m_N$ and $M_{W_R}$, the physics reach of the recently proposed high-intensity beam dump experiment SHiP, which is expected to produce a large sample of $D_s$ mesons. We compare these results with the corresponding reach of neutrinoless double beta decay experiments, as well as like-sign dilepto…
The present unitarity triangle fit, whose essential input is represented by the s to d and b to d transition processes, fully agrees with the SM. However, most of the phenomena involving b to s transitions are still largely unexplored and hence b to s phenomenology still constitutes a place for new physics manifestations, in spite of the tremendous experimental and theoretical progress on B to X_s gamma. We perform a systematic study of the CP conserving and violating SUSY contributions to b to s processes in a generic MSSM. We consider gluino exchange contributions including NLO QCD correctio…
We present an overview over the current status of laboratory experiments searching for (very) weakly coupled slim particles (WISPs). These experiments at the high precision frontier explore new physics beyond the standard model in a complementary way to high energy accelerators. The multitude of active and planned experiments shows a lively field and promises interesting new data in the near future.
The possibility of existence of a magnetic monopole has been surveyed by P. Dirac even in 1931, and then from the point of view of the modern theory by A.M. Polyakov and G.~ 'tHooft in 1974. Numerous and unsuccessful attempts of experimental search for monopole in cosmic rays and on accelerators in high energy particle collisions have been done. Also the searches have been carried out in mica for monopole tracks as well as for relict monopoles, entrapped by ferromagnetic inclusions in iron-ores, moon rock and meteorites. These entrapped monopoles, when released, would have the lowest velocitie…
In this review, we summarize tests of standard electroweak (EW) theory at the highest available energies as a precursor to the Large Hadron Collider (LHC) era. Our primary focus is on the published results (as of March 2010) from proton- antiproton collisions at $\sqrt{s}=1.96$ TeV at the Fermilab Tevatron collected using the CDF and D0 detectors. This review is very timely since the LHC scientific program is nearly underway with the first high-energy ($\sqrt{s}=7$ TeV) collisions about to begin. After presenting an overview of the EW sector of the standard model, we provide a summary of curre…
This document is one of a series of whitepapers from the USQCD collaboration. Here, we discuss opportunities for Lattice Quantum Chromodynamics (LQCD) in the research frontier in fundamental symmetries and signals for new physics. LQCD, in synergy with effective field theories and nuclear many-body studies, provides theoretical support to ongoing and planned experimental programs in searches for electric dipole moments of the nucleon, nuclei and atoms, decay of the proton, $n$-$\overline{n}$ oscillations, neutrinoless double-$β$ decay of a nucleus, conversion of muon to electron, precision mea…
The long-standing muon g-2 anomaly can be explained by heavy new physics particles through chirally enhanced contributions. It has been recently proposed that a muon collider running at center-of-mass energies of several TeV could test these new physics scenarios in a model-independent way, through the study of high-energy processes such as mu+ mu- --> h gamma. In this work, we validate these findings, based on effective field theories, by considering selected renormalizable simplified models and by computing this one-loop process in full generality. Furthermore, we explore the interplay of di…
Constraining magnetic monopoles and multiply charged particles with diphoton events at the LHC
Instituto de Física Corpuscular (IFIC), CSIC – Universitat de València（粒子物理研究所，西班牙科学理事会-瓦伦西亚大学）；Department of Physics and Astronomy, University of Alabama（阿拉巴马大学物理与天文学系）
The Monopole and Exotics Detector at the LHC (MoEDAL) is a pioneering LHC experiment designed to search for anomalously ionizing messengers of new physics such as magnetic monopoles or massive (pseudo-)stable charged particles. These are predicted to exist in a plethora of models beyond the Standard Model. Deployed at Interaction Point 8 (IP8) along the LHC ring, MoEDAL has taken data at centre-of-mass energies of 8 and 13 TeV. Its ground breaking physics program defines over 40 scenarios that yield potentially revolutionary insights into such foundational questions as: are there extra dimensi…
Searches for new physics will increasingly depend on identifying deviations from precision Standard Model (SM) predictions. Quantum Chromodynamics (QCD) will necessarily play a central role in this endeavor as it provides the framework for the parton model. However, as we move to higher orders and into extreme kinematic regions, we begin to see the full complexities of the QCD theory. Recent theoretical developments improve our ability to analyze both proton and nuclear PDFs across the full kinematic range. These developments are incorporated into the new nCTEQ15 PDFs, and we review these deve…
We present a gauge and Lorentz invariant model for the scattering of matter off magnetic poles, which justifies the presence of velocity-dependent magnetic charges as an effective description of either the behaviour of monopoles in scattering with matter or their production from matter particles at colliders. Hence, in such an approach, perturbativity of the magnetic charge is ensured for relative low velocities of monopoles with respect to matter particles. The model employs a ${\rm U(1)}_{\rm weak} \times {\rm U(1)}_{\rm strong}$ effective gauge field theory under which electrons and monopol…
The fundamental nature of Dark Matter is a central theme of the Snowmass 2021 process, extending across all Frontiers. In the last decade, advances in detector technology, analysis techniques and theoretical modeling have enabled a new generation of experiments and searches while broadening the types of candidates we can pursue. Over the next decade, there is great potential for discoveries that would transform our understanding of dark matter. In the following, we outline a road map for discovery developed in collaboration among the Frontiers. A strong portfolio of experiments that delves dee…
