Search for magnetic monopoles produced via the Schwinger mechanism.

Electrically charged particles can be created by the decay of strong enough electric fields, a phenomenon known as the Schwinger mechanism1. By electromagnetic duality, a sufficiently strong magnetic field would similarly produce magnetic monopoles, if they exist2. Magnetic monopoles are hypothetical fundamental particles that are predicted by several theories beyond the standard model3-7 but have never been experimentally detected. Searching for the existence of magnetic monopoles via the Schwinger mechanism has not yet been attempted, but it is advantageous, owing to the possibility of calculating its rate through semi-classical techniques without perturbation theory, as well as that the production of the magnetic monopoles should be enhanced by their finite size8,9 and strong coupling to photons2,10. Here we present a search for magnetic monopole production by the Schwinger mechanism in Pb-Pb heavy ion collisions at the Large Hadron Collider, producing the strongest known magnetic fields in the current Universe11. It was conducted by the MoEDAL experiment, whose trapping detectors were exposed to 0.235 per nanobarn, or approximately 1.8 × 109, of Pb-Pb collisions with 5.02-teraelectronvolt center-of-mass energy per collision in November 2018. A superconducting quantum interference device (SQUID) magnetometer scanned the trapping detectors of MoEDAL for the presence of magnetic charge, which would induce a persistent current in the SQUID. Magnetic monopoles with integer Dirac charges of 1, 2 and 3 and masses up to 75 gigaelectronvolts per speed of light squared were excluded by the analysis at the 95% confidence level. This provides a lower mass limit for finite-size magnetic monopoles from a collider search and greatly extends previous mass bounds.

First Search for Dyons with the Full MoEDAL Trapping Detector in 13 TeV pp Collisions.

The MoEDAL trapping detector consists of approximately 800 kg of aluminum volumes. It was exposed during run 2 of the LHC program to 6.46 fb^{-1} of 13 TeV proton-proton collisions at the LHCb interaction point. Evidence for dyons (particles with electric and magnetic charge) captured in the trapping detector was sought by passing the aluminum volumes comprising the detector through a superconducting quantum interference device (SQUID) magnetometer. The presence of a trapped dyon would be signaled by a persistent current induced in the SQUID magnetometer. On the basis of a Drell-Yan production model, we exclude dyons with a magnetic charge ranging up to five Dirac charges (5g_{D}) and an electric charge up to 200 times the fundamental electric charge for mass limits in the range 870-3120 GeV and also monopoles with magnetic charge up to and including 5g_{D} with mass limits in the range 870-2040 GeV.

Magnetic Monopole Search with the Full MoEDAL Trapping Detector in 13 TeV pp Collisions Interpreted in Photon-Fusion and Drell-Yan Production.

MoEDAL is designed to identify new physics in the form of stable or pseudostable highly ionizing particles produced in high-energy Large Hadron Collider (LHC) collisions. Here we update our previous search for magnetic monopoles in Run 2 using the full trapping detector with almost four times more material and almost twice more integrated luminosity. For the first time at the LHC, the data were interpreted in terms of photon-fusion monopole direct production in addition to the Drell-Yan-like mechanism. The MoEDAL trapping detector, consisting of 794 kg of aluminum samples installed in the forward and lateral regions, was exposed to 4.0 fb^{-1} of 13 TeV proton-proton collisions at the LHCb interaction point and analyzed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges equal to or above the Dirac charge are excluded in all samples. Monopole spins 0, ½, and 1 are considered and both velocity-independent and-dependent couplings are assumed. This search provides the best current laboratory constraints for monopoles with magnetic charges ranging from two to five times the Dirac charge.

Search for Magnetic Monopoles with the MoEDAL Forward Trapping Detector in 13 TeV 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 13 TeV proton-proton collisions using the trapping technique, extending a previous publication with 8 TeV data during LHC Run 1. A total of 222 kg 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 13 TeV pp collisions. The search probes mass ranges previously inaccessible to collider experiments for up to five times the Dirac charge.

[Use of 18F-FDG positron emission tomography in the diagnosis and evaluation of the efficiency of treatment for resistant anxiety-obsessive disorders].

The purpose of the investigation was to study the capacities of 18F-FDG positron emission tomography (PET) in the diagnosis and evaluation of the efficiency of treatment for resistant anxiety-obsessive disorders (AOD). 18F-FDG PET was performed in 21 patients with AOD. In 17 cases, the studies were made before and after therapy. Fourteen patients underwent stereotactic surgical intervention. Pretreatment 18F-FDG PET showed that the patients with AOD had hypermetabolism in the cingulated gyri, caudate nuclei, and thalamus in 7, 8, and 6 cases, respectively. A varying clinical improvement (by the Y-OCS and Spilberger scales) was observed in all the examinees after complex or drug treatment throughout the follow-up. According to the data of PET, these patients were observed to have significantly reduced metabolism of glucose in the anterior cingulated guri and its increased metabolism in the heads of the caudate nuclei and thalamus. The metabolic changes detected by PET are strongly and moderately correlated with the pattern of a clinical picture (p < 0.05). It is concluded that the use of 18F-FDG PET makes it possible to provide more accurate insight into the pathogenetic mechanisms responsible for the development of AOD, to objectify the choice of targeted intracerebral structures in order to perform stereotactic neurosurgical interventions, and to optimize drug therapy and to evaluate the efficiency of the treatment performed in early periods.

Differential approach to psychosurgery of obsessive disorders.

One of the most frequent indications of psychosurgical treatment is incurable obsessions. Up to now, capsulotomy or cingulotomy has been preferred. In our opinion, the variety of obsessive conditions require a more thorough approach to the selection of interbrain targets. Forty-seven patients with pure obsessive-compulsive disorders as well as disorders connected with depressions, epileptic syndrome, schizophreniform state and Gilles de la Tourette's syndrome with extremely severe resistance to medical therapy were examined. Eighteen patients were operated on. Surgical treatment is permissible only in cases fulfilling the three following criteria: (1) clinicopsychopathological permissibility (duration of disease, resistance to medication, psychopathological status); (2) physiological permissibility (the presence of a brain target, defining the psychopathological status), and (3) technical permissibility (the availability of proper stereotactic, imaging, electrophysiological and other apparatus necessary to carry out the surgical treatment). One supposes that the outcome of surgical treatment is determined by all three criteria. For the purpose of improving the efficiency of stereotactic treatment, a number of methods of surgical treatment depending on the psychopathological status are suggested. For example, in case of comorbidity of obsession with the epileptiform syndrome, we suggest cingulotomy (capsulotomy) and amygdalotomy; in case of comorbidity with depression we suggest cingulotomy and innominatotomy. The long-term observation of the outcome of stereotactic treatment covers a period from 2 up to 9 years.

[Stereotaxic cingulotomy in the complex treatment of a schizophrenic patient with obsessive-compulsive disorder, resistant to treatment]. / Stereotaksicheskaia tsingulotomiia v kompleksnom lechenii bol'nogo shizofreniei s terapevticheski rezistentnymi obsessivno-kompul'- sivnymi narusheniiami.

The authors describe a case of continuous conservative treatment of a patient suffering from severe obsessions. At the definite stage of the disease, the patient underwent psychosurgical operation--bilateral anterior stereotaxic cingulotomy . The surgical intervention was necessitated by dramatic and steady deterioration of the patient's condition, loss of work fitness, suggesting official registration of disability; appearance of suicidal intentions. After the operation the patient started his work again in accordance with his specialty; the question about disability registration did not arise any more.

[Electrical resistance of nerve tissue as a diagnostic criterion of pre-convulsive states]. / Elektricheskoe soprotivlenie nervnoi tkani kak diagnosticheskii kriterii predsudorozhnogo sostoianiia.

For diagnosing pre-convulsive states use is made, as a rule, of electroencephalography. This method, however, not always gives satisfactory results. The authors present the results of experimental studies of the nervous tissue impedance in the period preceding the convulsive seizure induced in laboratory animals by electric stimulation of the limbic structures of the brain. The experiments showed that a few seconds before the generalization of the convulsive process one could note certain changes in the electric conductivity of the nervous tissue. These changes make it possible to take measures for preventing the seizure.

[Regulation of complex forms of animal behavior on the basis of electric stimulation of the emotionogenic structures of the brain]. / Reguliatsiia slozhnykh form povedeniia zhivotnogo na osnove élektricheskogo razdrazheniia émotsiogennykh struktur mozga

The paper considers the possibility of controlling animal behaviour by acting on the positive emotional centres. It has been shown that in an experimental chamber under certain conditions of stimulation it is possible to control the motor-serach behaviour of dogs. This emphasized the possibility, in principal, for evolving biotechnical control systems of the "technical facility-bioobject" class.