Search for the Dirac monopole by means of vavilov-cherenkov radiation at the 70 Gev IHEP (Institute for High Energy Physics Serpukhov) proton synchrotron

At the proton energy of 70 GeV on the internal target of the IHEP proton synchrotron the search was made for magnetic charges over the Vavilov-Cherenkov radiation and characteristic polarization. Eight Cherenkov counters of a special construction served as detectors. Possible events were recorded with two fast five-ray oscillographs triggered by 6-fold coincidences. The efficiency of the magnetic charge recording was about 10%.The proton beam of 6.4×10¹⁴ intensity traversed the target-radiator; and not a single case of the production of the Dirac monopole with the magnetic charge from minimal one of about 2/3g _D (g _D =68.5e) up to2g _D was recorded. This means that in the conditions of our experiment the upper boundary of the cross section of the Dirac monopole production by 70 GeV protons per nucleon of Si and O nuclei for magnetic charges of masses from 3 up to 5·5m_p was found to be(95%) 10^–40 cm².On leave fromDepartment of Nuclear Physics, Comenius University, Bratislava, Czechoslovakia.The authors express their gratitude to the workers of the enterprise Dioptra (Turnov, SSR) for making of optical details for the device for SDM.     

Chinese Physics C(Formerly High Energy Physics and Nuclear Physics)

<正>Monthly,founded in 1977Published monthly in hard copy by Science Press and online by the Institute of High Energy Physics of the Chinese Academy of Sciences(domestic)and by IOP Publishing,Temple Circus,Temple Way,Bristol BS1 6HG,UK(international).     

Investigation of double-beta decay at the Institute of Theoretical and Experimental Physics (ITEP, Moscow)

Investigation of neutrinoless double-beta (2β0ν) decay is presently being considered as one of the most important problems in particle physics and cosmology Interest in the problem was quickened by the observation of neutrino oscillations. The results of oscillation experiments determine the mass differences between different neutrino flavors, and the observation of neutrinoless decay may fix the absolute scale and the hierarchy of the neutrino masses. Investigation of 2β0ν decay is the most efficient method for solving the problem of whether the neutrino is a Dirae or a Majorana particle, Physicists from the Institute of Theoretical and Experimental Physics (ITEP, Moscow) have been participating actively in solving this problem. They initiated and pioneered the application of semiconductor detectors manufactured from enriched germanium to searches for the double-beta decay of ⁷⁶Ge. Investigations with ⁷⁶Ge provided the most important results. At present, ITEP physicists are taking active part in four very large projects, GERDA. Majorana, EXO, and NEMO, which are capable of recording 2β0ν decay at a Majorana neutrino mass of 〈m _ν〉 ≈ 10^?2 eV.     

Institute of Theoretical and Experimental Physics (ITEP, Moscow) in the H1 experiment

A group of researchers from the Institute of Theoretical and Experimental Physics (ITEP, Moscow) took part at almost all stages of the H1 experiment performed at the HERA collider (Hamburg) in order to study lepton-proton interactions at high energies. Several subdetectors of the H1 detector were developed, designed, and constructed at the ITEP industrial workshop and domestic enterprises. In particular, the ITEP staff participated in assembling and tunning the equipment, servicing the detector and the data acquisition system, and analyzing and presenting the results. Researchers from ITEP have been playing a crucial role at many stages of the experiment to the present day.     

Half-a-century of gamma-ray astrophysics at the Max-Planck Institute for Extraterrestrial Physics

The European Physical Journal H - This is a tutorial for the many-worlds theory by Everett, which includes some of my personal views. It has two main parts. The first main part shows the emergence...     

Memorable Years for Synchrotron Radiation at the Institute of Nuclear Physics in Novosibirsk

In the early 1970s, the Institute of Nuclear Physics (INP) in Novosibirsk was a unique place in the world of accelerator physics. There were three operational electron-positron storage rings at the institution. All together, they covered beam operational energies from 200 MeV up to 2.2 GeV. It was not a big surprise for the developers of these state-of-the-art machines when the first users of synchrotron radiation showed up at the doorsteps of the Institute of Nuclear Physics, eager to take advantage of such unique radiation sources. And how very unique they were! Compared with several already relatively well-established operational synchrotrons around the world, such as DESY in Hamburg, NINA in Darsbury, and three synchrotrons in the Soviet Union—one at the Physical Institute in Pakhra, another at the Tomsk Polytechnical Institute, and a third at the Erevan Physical Institute—the storage ring sources provided much more stable and brighter radiation beams. Several storage rings built at that time in locations such as Japan, the US, and France were also on the verge of becoming available for synchrotron radiation users.     

On the history of the Linear Accelerator Department at the Institute for Theoretical and Experimental Physics (ITEP, Moscow)

These memoirs are devoted to the Institute’s anniversary and present the history of the Linear Accelerator Department at ITEP. Some studies are described in which I was involved. During more than 40 years. I worked with Professor I.M. Kapchinsky (1919–1993), a world-renowned scientist, the founder of the department. References are given to Kapchinsky’s monographs and to some of the works that were performed under his supervision and were published in proceedings of accelerator conferences. Many active scientists, engineers, and technicians are mentioned who participate in the achievements of the department, which made a significant contribution to the development of accelerator science and engineering in Russia and worldwide.     

High Energy Density Physics Studies at the Facility for Antiprotons and Ion Research: the HEDgeHOB Collaboration

The forthcoming F acility for A ntiprotons and I on R esearch (FAIR) at Darmstadt, is going to be a unique accelerator facility that will deliver high quality, strongly bunched, well focused, intense beams of heavy ions that will lead to unprecedented specific power deposition in solid matter. This will generate macroscopic samples of H igh E nergy D ensity (HED) matter with fairly uniform physical conditions. These samples can be used to study the thermophysical and transport properties of HED matter. Extensive theoretical work has been carried out over the past decade to design numerous dedicated experiments to study HED physics at the FAIR, which has provided the basis for the HEDgeHOB ( H igh E nergy D ensity Matter Ge nerated by H eavy I o n B eams) scientific proposal. This work is still in progress as the feasibility studies for more experimental schemes are being carried out. Another, very important research area that will benefit tremendously from the FAIR facility, is the production of radioactive beams. A superconducting fragment separator, Super–FRS is being designed for the production and separation of rare radioactive isotopes. Unlike the HED targets, the Super–FRS production target should not be destroyed or damaged by the beam, but should remain intact during the long experimental campaign. However, the high level of specific power deposited in the production target by the high intensity ion beam at FAIR, could cause serious problems to the target survival. These HED issues related to the Super–FRS production target are also discussed in the present paper (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Matrix hodoscopes for the Oka (Protvino) and NA62 (SPS,CERN) experimental setups

The matrix hodoscope of the OKA experimental setup and a prototype of the hodoscope for the NA62 experiment are described. The design of both hodoscopes is presented. The requirements for the hodoscope prototype are listed, and the efficiency and the time resolution obtained on the basis of experimental data are quoted.     

强子化过程的手征奇异性质

基于Nambu-Jona-Lasinio(NJL)模型讨论了有限温度､有限密度下的强子化过程,考虑夸克-反夸克对转换成两个介子的情形,其微分散射截面作为质心系能量s,温度T和化学势的函数被计算到1/N_c展开的第一阶.着重考察有限密度情形手征对称性对强子化过程的影响.     

Experimental upper limit on diffractive dissociation in muon-neutrino interaction with photoemulsion nuclei according to data of the E-128 experiment (Protvino)

The phenomenon of diffractive dissociation is experimentally estimated for neutrino interaction with photoemulsion nuclei. The results are based on data obtained in the SCIP experiment performed in a neutrino beam at the U-70 accelerator (Protvino). The data sample subjected to analysis included 670 charged-current events corresponding to neutrino interactions in the vertex detector. Events in which the Bjorken variable was x=0–0.1 were selected from this sample. Upon going over to the variable x′, which takes into account the nucleon mass, we set an upper limit of 0.53±0.07 on the diffractive-dissociation contribution to the total charged-current cross section.     

Epithermal Neutron Activation Analysis at the IBR-2 reactor of the Frank Laboratory of Neutron Physics at the Joint Institute for Nuclear Research (Dubna)

Experience of the Neutron Activation Analysis (NAA) Department in employing epithermal activation in life sciences and materials science is summarized. The potential of a combination of epithermal activation and the suppression of Compton scattering and contributions from cascade-photon-emitting elements for raising NAA-based analytical studies up to a new level are discussed.     

Progress of the nEDM experiment at the Paul Scherrer Institute

Advances in experimental searches for a neutron Electric Dipole Moment (nEDM, d _n ) are motivated by the potential discovery of a new source of CP violation beyond the Standard Model of particle physics. The nEDM experiment at the Paul Scherrer Institute (PSI), which with accumulated sensitivity of 1.09 × 10^?26 e?cm (September 2016) is currently the most sensitive nEDM experiment worldwide, uses the Ramsey technique of separated oscillatory fields applied to stored ultracold neutrons. The nEDM measurements depend upon precise information about the magnetic field, which is monitored by a ¹⁹⁹Hg co-magnetometer and an array of ¹³³Cs magnetometers. The principle of the magnetic field measurement is based on the optical detection of the Larmor precession frequency of atoms polarized by optical pumping. In this article we present the recent progress of the nEDM experiment as well as details of a magnetic field measurements with special focus on the laser-operated array of high-sensitivity ¹³³Cs magnetometers.     

Physics perspectives of the ALICE experiment at the large hadron collider

The large hadron collider (LHC) under construction at CERN will deliver ion beams up to centre of mass energies of the order of 5.5 TeV per nucleon, in case of lead. If compared to the available facilities for the study of nucleus-nucleus collisions (SpS and RHIC), this represents a huge step forward in terms of both volume and energy density that can be attained in nuclear interactions. ALICE (a large ion collider experiment) is the only detector specifically designed for the physics of nuclear collisions at LHC, even though it can also study high cross-section processes occurring in proton-proton collisions. The main goal of the experiment is to observe and study the phase transition from hadronic matter to deconfined partonic matter (quark gluon plasma —QGP). ALICE is conceived as a general-purpose detector and will address most of the phenomena related to the QGP formation at LHC energies: for this purpose, a large fraction of the hadrons, leptons and photons produced in each interaction will be measured and identified.     

Superconducting Multipole Wigglers for Generating Synchrotron Radiation at the Budker Institute of Nuclear Physics

Physics of Particles and Nuclei Letters - Superconducting multipole insertion devices (wigglers and undulators) used to generate synchrotron radiation significantly increase the photon flux,...     

Equivalent states of muonium and implanted hydrogen in silicon (experiment)

Main experimental data on the hydrogen-like states with an anisotropic hyperfine structure forming in silicon single crystals in the implantation of high energy muons and protons are presented. The characteristics of the “anomalous” muonium (Mu^*) and hydrogen-containing silicon AA9 states studied by the muon spin rotation (μSR) and ESR techniques in silicon with a due inclusion of the isotope effect are shown to be similar, thus suggesting the existence of two equivalent structures in silicon, Mu^* and AA9, differing only in the mass of the paramagnetic center.     

High spin states in ~(71)Ga

Excited states in the odd-A nucleus ~(71)Ga have been studied via the ~(70)Zn(~7 Li,α2 n)~(71)Ga fusion-evaporation reaction with incident beam energies of 30 and 35 MeV.The level scheme is established up to spin I~π=(29/2~+)and an excitation energy ～6.6 MeV.A previously known sequence built on the 9/2~+ state is extended as a novel rotational band originating from the v(g_(9/2)~2) alignment.Furthermore,a negative-parity sequence is also reported.The observed energy levels of ~(71)Ga have been interpreted in the framework of the nuclear shell model(SM).