Frequency signal acquisition of scalar atomic magnetometer based on using TDC and FPGA
Ge, Y. H.; Chen, Q. Y.; Zhang, Y. F.; Xia, M. Y.
2017-09-01
An improved equal precision frequency measurement method is presented for acquisition of frequency signal output from high sensitivity scalar atomic magnetometers. The frequency range to be measured is from 75 kHz to 350 kHz with a resolution better than 0.01 Hz, and the sampling rate should be at least 10 Hz. To meet the requirements on dynamic range, measurement accuracy and speed, at least eight significant digits must be kept. The TDC and FPGA are used to improve the traditional equal precision method. The FPGA acts as the controlling and computing centre, while the TDC measures the time deviation to eliminate the counting error of ±1 reference signal. A prototype frequency detector is fabricated and tested. The measured data show that the design is viable and further improvement is possible.
Scalar magnetometers for space applications
DEFF Research Database (Denmark)
Primdahl, Fritz
magnetometer, offer stability and resolution well suited for the calibration purposes. Recent developments are discussed. The metastable Helium magnetometer also offers quasi-absolute scalar measurements, and the use of semiconductor tuned lasers replacing an RF-excited Helium lamp holds great promise...
Scalar Calibration of Vector Magnetometers
DEFF Research Database (Denmark)
Merayo, José M.G.; Brauer, Peter; Primdahl, Fritz
2000-01-01
The calibration parameters of a vector magnetometer are estimated only by the use of a scalar reference magnetometer. The method presented in this paper differs from those previously reported in its linearized parametrization. This allows the determination of three offsets or signals in the absence...... of a magnetic field, three scale factors for normalization of the axes and three non-orthogonality angles which build up an orthogonal system intrinsically in the sensor. The advantage of this method compared with others lies in its linear least squares estimator, which finds independently and uniquely...... the parameters for a given data set. Therefore, a magnetometer may be characterized inexpensively in the Earth's magnetic-field environment. This procedure has been used successfully in the pre-flight calibration of the state-of-the-art magnetometers on board the magnetic mapping satellites Orsted, Astrid-2...
Dynamic analysis of atomic magnetometer and co-magnetometer
Energy Technology Data Exchange (ETDEWEB)
Wang, Shihu, E-mail: 65980623@qq.com; Yu, Linke; Wang, Wei
2016-03-01
Some unsteady-state solutions of Bloch equation which well-describe the behavior of a magnetometer are obtained. These solutions are in accord with the experimental result of alkali-metal magnetometer and co-magnetometer gyroscope. Many interesting phenomena can be also achieved via the solutions. First, the measuring direction of a magnetometer changes with the variation of external magnetic field along z axis. And it could be used for measuring high frequency magnetic field. Then it can be extended that the co-magnetometer without compensated field can get better performance than simple atomic magnetometer due to the effect of polarized noble gas. Finally, we discussed the limits (bandwidth and so on) of atomic magnetometer and co-magnetometer with the Bloch equation of spins. These phenomena, which have not been mentioned before, may contribute to the development of atomic magnetometer and co-magnetometer gyroscope.
Athermal fiber laser for the SWARM absolute scalar magnetometer
Fourcault, W.; Léger, J.-M.; Costes, V.; Fratter, I.; Mondin, L.
2017-11-01
The Absolute Scalar Magnetometer (ASM) developed by CEA-LETI/CNES is an optically pumped 4He magnetic field sensor based on the Zeeman effect and an electronic magnetic resonance whose effects are amplified by a laser pumping process [1-2]. Consequently, the role of the laser is to pump the 4He atoms at the D0 transition as well as to allow the magnetic resonance signal detection. The ASM will be the scalar magnetic reference instrument of the three ESA Swarm satellites to be launched in 2012 in order to carry out the best ever survey of the Earth magnetic field and its temporal evolution. The sensitivity and accuracy of this magnetometer based on 4He optical pumping depend directly on the characteristics of its light source, which is the key sub-system of the sensor. We describe in this paper the selected fiber laser architecture and its wavelength stabilization scheme. Its main performance in terms of spectral emission, optical power at 1083 nm and intensity noise characteristics in the frequency bands used for the operation of the magnetometer, are then presented. Environmental testing results (thermal vacuum cycling, vibrations, shocks and ageing) are also reported at the end of this paper.
High-Range Scalar Helium Magnetometer (HSHM) Project
National Aeronautics and Space Administration — This SBIR Phase I proposal describes development of a conceptual design for a High-range Scalar Helium Magnetometer (HSHM) for the field range +/-16 Gauss. The HSHM...
Atomic magnetometer for human magnetoencephalograpy.
Energy Technology Data Exchange (ETDEWEB)
Schwindt, Peter; Johnson, Cort N.
2010-12-01
We have developed a high sensitivity (<5 fTesla/{radical}Hz), fiber-optically coupled magnetometer to detect magnetic fields produced by the human brain. This is the first demonstration of a noncryogenic sensor that could replace cryogenic superconducting quantum interference device (SQUID) magnetometers in magnetoencephalography (MEG) and is an important advance in realizing cost-effective MEG. Within the sensor, a rubidium vapor is optically pumped with 795 laser light while field-induced optical rotations are measured with 780 nm laser light. Both beams share a single optical axis to maximize simplicity and compactness. In collaboration with neuroscientists at The Mind Research Network in Albuquerque, NM, the evoked responses resulting from median nerve and auditory stimulation were recorded with the atomic magnetometer and a commercial SQUID-based MEG system with signals comparing favorably. Multi-sensor operation has been demonstrated with two AMs placed on opposite sides of the head. Straightforward miniaturization would enable high-density sensor arrays for whole-head magnetoencephalography.
Fetal MCG with Atomic Magnetometer Array
Deland, Zack; Bulatowicz, Michael D.; Sulai, Ibrahim A.; Wahl, Colin P.; Wakai, Ronald T.; Walker, Thad G.
2016-05-01
We present results on the development of 87Rb atomic magnetometers for the detection of a fetal magnetocardiogram (fMCG). Operating in the spin-exchange relaxation free (SERF) regime, the magnetometers' sensitivities are reported at the 1 fT /√{ Hz } level. Environmental common-mode noise, including the field from the maternal heart, can be suppressed by operating the magnetometers in a gradiometric configuration. We report on schemes from implementing such gradiometers along with recent fMCG measurements. This work is supported by the National Institutes of Health.
A Miniature Wide Band Atomic Magnetometer
2011-12-01
current circuit is easiest to explain if we at first ignore the capacitors . The reference and the DAC output are combined by R401 and R402 to make...atomic magnetometer CSAC – Chip scale atomic clock DAC – Digital to Analog Converter DARPA – Defense Advanced Research Projects Agency DBR...Transform FPGA – Field Programmable Gate Array GHz – Gigahertz MEMS – Micro-Electro Mechanical System MF – z-component Magnetic Quantum Number, MF MFTFM
SCALAR MULTI-PASS ATOMIC MAGNETOMETER
2017-08-01
Signature// JOHN F. CARR, DR-4 Chief, Spectrum Warfare Division Sensors Directorate This report is published in...detector (PFD) part of a common phase- locked -loop chip, such as 4046. An advantage of this approach is that PFD measures the time between zero...emitter. In some configurations such as side- locked optical rotation probe beams, the increased power may be substantially negated by the added
Shah, Vishal; Vasilakis, Georgios; Romalis, Michael
2009-05-01
The fundamental sensitivity of an atomic magnetometer is limited by spin projection noise. In the case of uniform spin relaxation, it is well understood that it is not possible to improve the sensitivity using spin squeezing induced by quantum non-demolition (QND) measurement for measurement time scales longer than spin relaxation time [1, 2]. It is however possible to increase the bandwidth of the magnetometer using QND measurement. Here we experimentally demonstrate, in excellent agreement with the theory, an improvement in the bandwidth of our scalar alkali vapor atomic magnetometer using continuous QND measurement. We also investigate the possibility of improving sensitivity of our magnetometer in the special case in which the spin relaxation is time dependent. The case of time dependent spin relaxation naturally arises in high polarization regime in an alkali-alkali spin-exchange relaxation dominated atomic sample. [1] S. F. Huelga, Phys. Rev. Lett. 79, 3865 -- 3868, 1997. [2] M. Auzinsh, Phys. Rev. Lett. 93, 173002, 2004.
The atomic magnetometer: A new era in biomagnetism
Energy Technology Data Exchange (ETDEWEB)
Wakai, Ronald T., E-mail: rtwakai@wisc.edu [1005 Wisconsin Institutes for Medical Research, 1111 Highland Avenue, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States)
2014-11-07
The high cost and impracticality of SQUID (Superconducting QUantum Interference Device) magnetometers has limited the expansion of magnetoencephalography (MEG) and magnetocardiography (MCG), especially in countries where the cost of liquid helium is high. A recent breakthrough, however, has the potential to radically change this situation. In 2003, a group at Princeton University demonstrated an atomic magnetometer, known as the SERF (spin-exchange free relaxation) magnetometer, with unprecedented sensitivity. Since then, several research groups have utilized SERF magnetometers to record MEG, MCG, and fetal MCG signals. Despite some modest drawbacks, it now seems almost certain that SERF magnetometers can replace SQUIDs for many applications. With a price tag that is likely to be far less than that of SQUIDs, SERF magnetometers can propel the next wave of growth in biomagnetism.
Ultra-sensitive Magnetic Microscopy with an Atomic Magnetometer
Energy Technology Data Exchange (ETDEWEB)
Kim, Young Jin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-08-19
The PowerPoint presentation focused on research goals, specific information about the atomic magnetometer, response and resolution factors of the SERF magnetometer, FC+AM systems, tests of field transfer and resolution on FC, gradient cancellation, testing of AM performance, ideas for a multi-channel AM, including preliminary sensitivity testing, and a description of a 6 channel DAQ system. A few ideas for future work ended the presentation.
NQR detection of explosive simulants using RF atomic magnetometers
Monti, Mark C.; Alexson, Dimitri A.; Okamitsu, Jeffrey K.
2016-05-01
Nuclear Quadrupole Resonance (NQR) is a highly selective spectroscopic method that can be used to detect and identify a number of chemicals of interest to the defense, national security, and law enforcement community. In the past, there have been several documented attempts to utilize NQR to detect nitrogen bearing explosives using induction sensors to detect the NQR RF signatures. We present here our work on the NQR detection of explosive simulants using optically pumped RF atomic magnetometers. RF atomic magnetometers can provide an order of magnitude (or more) improvement in sensitivity versus induction sensors and can enable mitigation of RF interference, which has classically has been a problem for conventional NQR using induction sensors. We present the theory of operation of optically pumped RF atomic magnetometers along with the result of laboratory work on the detection of explosive simulant material. An outline of ongoing work will also be presented along with a path for a fieldable detection system.
Polarization enhanced Nuclear Quadrupole Resonance with an atomic magnetometer
Malone, Michael W.; Barrall, Geoffrey A.; Espy, Michelle A.; Monti, Mark C.; Alexson, Dimitri A.; Okamitsu, Jeffrey K.
2016-05-01
Nuclear Quadrupole Resonance (NQR) has been demonstrated for the detection of 14-N in explosive compounds. Application of a material specific radio-frequency (RF) pulse excites a response typically detected with a wire- wound antenna. NQR is non-contact and material specific, however fields produced by NQR are typically very weak, making demonstration of practical utility challenging. For certain materials, the NQR signal can be increased by transferring polarization from hydrogen nuclei to nitrogen nuclei using external magnetic fields. This polarization enhancement (PE) can enhance the NQR signal by an order of magnitude or more. Atomic magnetometers (AM) have been shown to improve detection sensitivity beyond a conventional antenna by a similar amount. AM sensors are immune to piezo-electric effects that hamper conventional NQR, and can be combined to form a gradiometer for effective RF noise cancellation. In principle, combining polarization enhancement with atomic magnetometer detection should yield improvement in signal-to-noise ratio that is the product of the two methods, 100-fold or more over conventional NQR. However both methods are even more exotic than traditional NQR, and have never been combined due to challenges in operating a large magnetic field and ultra-sensitive magnetic field sensor in proximity. Here we present NQR with and without PE with an atomic magnetometer, demonstrating signal enhancement greater than 20-fold for ammonium nitrate. We also demonstrate PE for PETN using a traditional coil for detection with an enhancement factor of 10. Experimental methods and future applications are discussed.
Three axis vector atomic magnetometer utilizing polarimetric technique
Energy Technology Data Exchange (ETDEWEB)
Pradhan, Swarupananda, E-mail: spradhan@barc.gov.in, E-mail: pradhans75@gmail.com [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai 400085, India and Homi Bhabha National Institute, Department of Atomic Energy, Mumbai 400094 (India)
2016-09-15
The three axis vector magnetic field measurement based on the interaction of a single elliptically polarized light beam with an atomic system is described. The magnetic field direction dependent atomic responses are extracted by the polarimetric detection in combination with laser frequency modulation and magnetic field modulation techniques. The magnetometer geometry offers additional critical requirements like compact size and large dynamic range for space application. Further, the three axis magnetic field is measured using only the reflected signal (one polarization component) from the polarimeter and thus can be easily expanded to make spatial array of detectors and/or high sensitivity field gradient measurement as required for biomedical application.
Machine Learning Based Localization and Classification with Atomic Magnetometers
Deans, Cameron; Griffin, Lewis D.; Marmugi, Luca; Renzoni, Ferruccio
2018-01-01
We demonstrate identification of position, material, orientation, and shape of objects imaged by a Rb 85 atomic magnetometer performing electromagnetic induction imaging supported by machine learning. Machine learning maximizes the information extracted from the images created by the magnetometer, demonstrating the use of hidden data. Localization 2.6 times better than the spatial resolution of the imaging system and successful classification up to 97% are obtained. This circumvents the need of solving the inverse problem and demonstrates the extension of machine learning to diffusive systems, such as low-frequency electrodynamics in media. Automated collection of task-relevant information from quantum-based electromagnetic imaging will have a relevant impact from biomedicine to security.
Multi-flux-transformer MRI detection with an atomic magnetometer.
Savukov, Igor; Karaulanov, Todor
2014-12-01
Recently, anatomical ultra-low field (ULF) MRI has been demonstrated with an atomic magnetometer (AM). A flux-transformer (FT) has been used for decoupling MRI fields and gradients to avoid their negative effects on AM performance. The field of view (FOV) was limited because of the need to compromise between the size of the FT input coil and MRI sensitivity per voxel. Multi-channel acquisition is a well-known solution to increase FOV without significantly reducing sensitivity. In this paper, we demonstrate twofold FOV increase with the use of three FT input coils. We also show that it is possible to use a single atomic magnetometer and single acquisition channel to acquire three independent MRI signals by applying a frequency-encoding gradient along the direction of the detection array span. The approach can be generalized to more channels and can be critical for imaging applications of non-cryogenic ULF MRI where FOV needs to be large, including head, hand, spine, and whole-body imaging. Copyright © 2014 Elsevier Inc. All rights reserved.
Rb atomic magnetometer toward EDM experiment with laser cooled francium atoms
Inoue, Takeshi; Ando, Shun; Aoki, Takahiro; Arikawa, Hiroshi; Harada, Ken-Ichi; Hayamizu, Tomohiro; Ishikawa, Taisuke; Itoh, Masatoshi; Kato, Ko; Kawamura, Hirokazu; Sakamoto, Kosuke; Uchiyama, Aiko; Asahi, Koichiro; Yoshimi, Akihiro; Sakemi, Yasuhiro
2014-09-01
A permanent electric dipole moment (EDM) of a particle or an atom is a suited observable to test the physics beyond the standard model. We plan to search for the electron EDM by using the laser cooled francium (Fr) atom, since the Fr atom has a large enhancement factor of the electron EDM and the laser cooling techniques can suppress both statistical and systematic errors. In the EDM experiment, a fluctuation of the magnetic field is a main source of the errors. In order to achieve the high precision magnetometry, a magnetometer based on the nonlinear magneto-optical rotation effect of the Rb atom is under development. A long coherence time of Rb atom is the key issue for the highly sensitive detection of the field fluctuations. The coherence time is limited due both to collisions with an inner surface of a cell contained the Rb atom and to residual field in a magnetic shield. We prepared the cell coated with an anti-relaxation material and measured the relaxation time. A degauss of the shield was performed to eliminate the residual field. We will report the present status of the magnetometer. A permanent electric dipole moment (EDM) of a particle or an atom is a suited observable to test the physics beyond the standard model. We plan to search for the electron EDM by using the laser cooled francium (Fr) atom, since the Fr atom has a large enhancement factor of the electron EDM and the laser cooling techniques can suppress both statistical and systematic errors. In the EDM experiment, a fluctuation of the magnetic field is a main source of the errors. In order to achieve the high precision magnetometry, a magnetometer based on the nonlinear magneto-optical rotation effect of the Rb atom is under development. A long coherence time of Rb atom is the key issue for the highly sensitive detection of the field fluctuations. The coherence time is limited due both to collisions with an inner surface of a cell contained the Rb atom and to residual field in a magnetic shield
Scalar-pseudoscalar interaction in the francium atom
Skripnikov, L. V.; Maison, D. E.; Mosyagin, N. S.
2017-02-01
Fr atom can be successively used to search for the atomic permanent electric dipole moment (EDM) [Hyperfine Interact. 236, 53 (2015), 10.1007/s10751-015-1193-1; J. Phys.: Conference Series 691, 012017 (2016), 10.1088/1742-6596/691/1/012017]. It can be induced by the permanent electron EDM predicted by modern extensions of the standard model to be nonzero at the level accessible by the new generation of EDM experiments. We consider another mechanism of the atomic EDM generation in Fr. This is caused by the scalar-pseudoscalar nucleus-electron neutral current interaction with the dimensionless strength constant kT ,P. Similar to the electron EDM this interaction violates both spatial parity and time-reversal symmetries and can also induce permanent atomic EDM. It was shown in [Phys. Rev. D 89, 056006 (2014), 10.1103/PhysRevD.89.056006] that the scalar-pseudoscalar contribution to the atomic EDM can dominate over the direct contribution from the electron EDM within the standard model. We report high-accuracy combined all-electron and two-step relativistic coupled cluster treatment of the effect from the scalar-pseudoscalar interaction in the Fr atom. Up to the quadruple cluster amplitudes within the coupled cluster method with single, double, triple, and noniterative quadruple amplitudes, CCSDT(Q), were included in correlation treatment. This calculation is required for the interpretation of the experimental data in terms of kT ,P. The resulted EDM of the Fr atom expressed in terms of kT ,P is dFr=kT ,P4.50 ×10-18e cm , where e is the (negative) charge of the electron. The value of the ionization potential of the 2S1 /2 ground state of Fr calculated within the same methods is in very good agreement with the experimental datum.
Search for Ultralight Scalar Dark Matter with Atomic Spectroscopy.
Van Tilburg, Ken; Leefer, Nathan; Bougas, Lykourgos; Budker, Dmitry
2015-07-03
We report new limits on ultralight scalar dark matter (DM) with dilatonlike couplings to photons that can induce oscillations in the fine-structure constant α. Atomic dysprosium exhibits an electronic structure with two nearly degenerate levels whose energy splitting is sensitive to changes in α. Spectroscopy data for two isotopes of dysprosium over a two-year span are analyzed for coherent oscillations with angular frequencies below 1 rad s-1. No signal consistent with a DM coupling is identified, leading to new constraints on dilatonlike photon couplings over a wide mass range. Under the assumption that the scalar field comprises all of the DM, our limits on the coupling exceed those from equivalence-principle tests by up to 4 orders of magnitude for masses below 3×10(-18) eV. Excess oscillatory power, inconsistent with fine-structure variation, is detected in a control channel, and is likely due to a systematic effect. Our atomic spectroscopy limits on DM are the first of their kind, and leave substantial room for improvement with state-of-the-art atomic clocks.
Measurement Sensitivity Improvement of All-Optical Atomic Spin Magnetometer by Suppressing Noises
Directory of Open Access Journals (Sweden)
Xiyuan Chen
2016-06-01
Full Text Available Quantum manipulation technology and photoelectric detection technology have jointly facilitated the rapid development of ultra-sensitive atomic spin magnetometers. To improve the output signal and sensitivity of the spin-exchange-relaxation-free (SERF atomic spin magnetometer, the noises influencing on the output signal and the sensitivity were analyzed, and the corresponding noise suppression methods were presented. The magnetic field noises, including the residual magnetic field noise and the light shift noise, were reduced to approximately zero by employing the magnetic field compensation method and by adjusting the frequency of the pump beam, respectively. With respect to the operation temperature, the simulation results showed that the temperature of the potassium atomic spin magnetometer realizing the spin-exchange relaxation-free regime was 180 °C. Moreover, the fluctuation noises of the frequency and the power were suppressed by using the frequency and the power stable systems. The experimental power stability results showed that the light intensity stability was enhanced 10%. Contrast experiments on the sensitivity were carried out to demonstrate the validity of the suppression methods. Finally, a sensitivity of 13 fT/Hz1/2 was successfully achieved by suppressing noises and optimizing parameters.
Is light narrowing possible with dense-vapor paraffin coated cells for atomic magnetometers?
Han, Runqi; Balabas, Mikhail; Hovde, Chris; Li, Wenhao; Roig, Hector Masia; Wang, Tao; Wickenbrock, Arne; Zhivun, Elena; You, Zheng; Budker, Dmitry
2017-12-01
We investigated the operation of an all-optical rubidium-87 atomic magnetometer with amplitude-modulated light. To study the suppression of spin-exchange relaxation, three schemes of pumping were implemented with room-temperature and heated paraffin coated vacuum cells. Efficient pumping and accumulation of atoms in the F=2 ground state were obtained. However, the sought-for narrowing of the resonance lines has not been achieved. A theoretical analysis of the polarization degree is presented to illustrate the absence of light narrowing due to radiation trapping at high temperature.
Laser pumping Cs atom magnetometer of theory research based on gradient tensor measuring
Energy Technology Data Exchange (ETDEWEB)
Yang Zhang; Chong Kang; Wang Qingtao; Lei Cheng; Zheng Caiping, E-mail: zhangyang@hrbeu.edu.cn [College of Science, Harbin Engineering University, Harbin 150001 (China)
2011-02-01
At present, due to space exploration, military technology, geological exploration, magnetic navigation, medical diagnosis and biological magnetic fields study of the needs of research and development, the magnetometer is given strong driving force. In this paper, it will discuss the theoretical analysis and system design of laser pumping cesium magnetometer, cesium atomic energy level formed hyperfine structure with the I-J coupling, the hyperfine structure has been further split into Zeeman sublevels for the effects of magnetic field. To use laser pump and RF magnetic field make electrons transition in the hyperfine structure to produce the results of magneto-optical double resonance, and ultimately through the resonant frequency will be able to achieve accurate value of the external magnetic field. On this basis, we further have a discussion about magnetic gradient tensor measuring method. To a large extent, it increases the magnetic field measurement of information.
Scalar Aharonov–Bohm Phase in Ramsey Atom Interferometry under Time-Varying Potential
Directory of Open Access Journals (Sweden)
Atsuo Morinaga
2016-08-01
Full Text Available In a Ramsey atom interferometer excited by two electromagnetic fields, if atoms are under a time-varying scalar potential during the interrogation time, the phase of the Ramsey fringes shifts owing to the scalar Aharonov–Bohm effect. The phase shift was precisely examined using a Ramsey atom interferometer with a two-photon Raman transition under the second-order Zeeman potential, and a formula for the phase shift was derived. Using the derived formula, the frequency shift due to the scalar Aharonov–Bohm effect in the frequency standards utilizing the Ramsey atom interferometer was discussed.
An atomic magnetometer with autonomous frequency stabilization and large dynamic range
Energy Technology Data Exchange (ETDEWEB)
Pradhan, S., E-mail: spradhan@barc.gov.in, E-mail: pradhans75@gmail.com; Poornima,; Dasgupta, K. [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai 85 (India); Homi Bhabha National Institute, Department of Atomic Energy, Mumbai 85 (India); Mishra, S.; Behera, R. [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai 85 (India)
2015-06-15
The operation of a highly sensitive atomic magnetometer using elliptically polarized resonant light is demonstrated. It is based on measurement of zero magnetic field resonance in degenerate two level systems using polarimetric detection. The transmitted light through the polarimeter is used for laser frequency stabilization, whereas reflected light is used for magnetic field measurement. Thus, the experimental geometry allows autonomous frequency stabilization of the laser frequency leading to compact operation of the overall device and has a preliminary sensitivity of <10 pT/Hz{sup 1/2} @ 1 Hz. Additionally, the dynamic range of the device is improved by feedback controlling the bias magnetic field without compromising on its sensitivity.
Directory of Open Access Journals (Sweden)
Sapunov V.A., Denisov A.Y., Saveliev D.V., Soloviev A.A., Khomutov S.Y., Borodin P.B., Narkhov E.D., Sergeev A.V., Shirokov A.N.
2016-12-01
Full Text Available This paper covers same results of the research directed at developing an absolute vector proton magnetometer POS-4 based on the switching bias magnetic fields methods. Due to the high absolute precision and stability magnetometer POS-4 found application not only for observatories and to directional drilling support of oi and gas well. Also we discuss the some basic errors of measurements and discuss the long-term experience in the testing of magnetic observatories ART and PARATUNKA.
Micro-fabricated atomic magnetometer with hybrid vector-scalar operation Project
National Aeronautics and Space Administration — Measurement of magnetic fields provides valuable information about charged particles and plasma interactions in the solar system, and about planetary dynamics and...
Aristoteles magnetometer system
Smith, Edward J.; Marquedant, Roy J.; Langel, Robert; Acuna, Mario
1991-12-01
A magnetometer system capable of meeting the stringent requirements of the Aristoteles mission is described. The system will comprise a three axis or Vector Flux gas Magnetometer (VFM) and a highly accurate resonance magnetometer, the Scalar Helium Magnetometer (SHM). Basic operational features of these instruments are described and their performance is related to the scientific objectives of the mission appropriate to the geomagnetic field measurements. The major requirements imposed on the spacecraft are summarized. Photographs and diagrams of both instruments are presented along with graphs of the sensitivity of the SHM to magnetic field orientation.
Jensen, Kasper; Budvytyte, Rima; Thomas, Rodrigo A.; Wang, Tian; Fuchs, Annette M.; Balabas, Mikhail V.; Vasilakis, Georgios; Mosgaard, Lars D.; Stærkind, Hans C.; Müller, Jörg H.; Heimburg, Thomas; Olesen, Søren-Peter; Polzik, Eugene S.
2016-07-01
Magnetic fields generated by human and animal organs, such as the heart, brain and nervous system carry information useful for biological and medical purposes. These magnetic fields are most commonly detected using cryogenically-cooled superconducting magnetometers. Here we present the first detection of action potentials from an animal nerve using an optical atomic magnetometer. Using an optimal design we are able to achieve the sensitivity dominated by the quantum shot noise of light and quantum projection noise of atomic spins. Such sensitivity allows us to measure the nerve impulse with a miniature room-temperature sensor which is a critical advantage for biomedical applications. Positioning the sensor at a distance of a few millimeters from the nerve, corresponding to the distance between the skin and nerves in biological studies, we detect the magnetic field generated by an action potential of a frog sciatic nerve. From the magnetic field measurements we determine the activity of the nerve and the temporal shape of the nerve impulse. This work opens new ways towards implementing optical magnetometers as practical devices for medical diagnostics.
Magnetoencephalography with a Cs-based high-sensitivity compact atomic magnetometer
Sheng, Jingwei; Wan, Shuangai; Sun, Yifan; Dou, Rongshe; Guo, Yuhao; Wei, Kequan; He, Kaiyan; Qin, Jie; Gao, Jia-Hong
2017-09-01
In recent years, substantial progress has been made in developing a new generation of magnetoencephalography (MEG) with a spin-exchange relaxation free (SERF)-based atomic magnetometer (AM). An AM employs alkali atoms to detect weak magnetic fields. A compact AM array with high sensitivity is crucial to the design; however, most proposed compact AMs are potassium (K)- or rubidium (Rb)-based with single beam configurations. In the present study, a pump-probe two beam configuration with a Cesium (Cs)-based AM (Cs-AM) is introduced to detect human neuronal magnetic fields. The length of the vapor cell is 4 mm, which can fully satisfy the need of designing a compact sensor array. Compared with state-of-the-art compact AMs, our new Cs-AM has two advantages. First, it can be operated in a SERF regime, requiring much lower heating temperature, which benefits the sensor with a closer distance to scalp due to ease of thermal insulation and less electric heating noise interference. Second, the two-beam configuration in the design can achieve higher sensitivity. It is free of magnetic modulation, which is necessary in one-beam AMs; however, such modulation may cause other interference in multi-channel circumstances. In the frequency band between 10 Hz and 30 Hz, the noise level of the proposed Cs-AM is approximately 10 f T/Hz1/2, which is comparable with state-of-the-art K- or Rb-based compact AMs. The performance of the Cs-AM was verified by measuring human auditory evoked fields (AEFs) in reference to commercial superconducting quantum interference device (SQUID) channels. By using a Cs-AM, we observed a clear peak in AEFs around 100 ms (M100) with a much larger amplitude compared with that of a SQUID, and the temporal profiles of the two devices were in good agreement. The results indicate the possibility of using the compact Cs-AM for MEG recordings, and the current Cs-AM has the potential to be designed for multi-sensor arrays and gradiometers for future neuroscience
Study of the scalar-pseudoscalar interaction in the francium atom
Skripnikov, L V; Mosyagin, N S
2016-01-01
Fr atom can be successively used to search for the atomic permanent electric dipole moment (EDM) [Hyperfine Interactions 236, 53 (2015); Journal of Physics: Conference Series 691, 012017 (2016)]. It can be induced by the permanent electron EDM predicted by modern extensions of the standard model to be nonzero at the level accessible by the new generation of EDM experiments. We consider another mechanism of the atomic EDM generation in Fr. This is caused by the scalar-pseudoscalar nucleus-electron neutral current interaction with the dimensionless strength constant, $k_{T,P}$. Similar to the electron EDM this interaction violates both spatial parity and time-reversal symmetries and can also induce permanent atomic EDM. It was shown in [Phys. Rev. D 89, 056006 (2014)] that the scalar-pseudoscalar contribution to the atomic EDM can dominate over the direct contribution from the electron EDM within the standard model. We report high-accuracy combined all-electron and two-step relativistic coupled cluster treatmen...
An unshielded radio-frequency atomic magnetometer with sub-femtoTesla sensitivity
Directory of Open Access Journals (Sweden)
David A. Keder
2014-12-01
Full Text Available We demonstrate a radio-frequency potassium-vapor magnetometer operating with sensitivities of 0.3 fT/ Hz at 0.5 MHz and 0.9 fT/ Hz at 1.31 MHz in the absence of radio-frequency and mu-metal or magnetic shielding. The use of spatially separated magnetometers, two voxels within the same cell, permits for the subtraction of common mode noise and the retention of a gradient signal, as from a local source. At 0.5 MHz the common mode noise was white and measured to be 3.4 fT/ Hz ; upon subtraction the noise returned to the values observed when the magnetometer was shielded. At 1.31 MHz, the common mode noise was from a nearby radio station and was reduced by a factor of 33 upon subtraction, limited only by the radio signal picked up by receiver electronics. Potential applications include in-the-field low-field magnetic resonance, such as the use of nuclear quadrupole resonance for the detection of explosives.
Fan, Wenfeng; Liu, Gang; Li, Rujie; Quan, Wei; Jiang, Liwei; Duan, Lihong
2017-09-01
High performance spin-exchange-relaxation-free (SERF) gyroscopes require stable and homogeneous magnetic fields. These fields are usually sensitive to temperature. In this paper, a three-axis atomic magnetometer to measure the temperature dependence of fields inside the magnetic shields for a SERF gyroscope prototype is constructed and tested. Based on a three-beam configuration, three-axis vector capability is obtained by a cross-modulation scheme of the magnetic field components along orthogonal axes and subsequent demodulation of the relevant probe signals. The relative temperature dependence of magnetic fields inside the prototype shields is measured to be 0.03 -0.12~K-1 . The results are useful for estimating the necessary precision of temperature control in both a SERF gyroscope and its fundamental physics applications.
Cooper, Robert J.; Prescott, David W.; Matz, Peter; Sauer, Karen L.; Dural, Nezih; Romalis, Michael V.; Foley, Elizabeth L.; Kornack, Thomas W.; Monti, Mark; Okamitsu, Jeffrey
2016-12-01
An array of four 87Rb vector magnetometers is used to detect nuclear quadrupole resonance signals in an unshielded environment at 1 MHz. With a baseline of 25 cm, the length of the array, radio-frequency interference mitigation is also demonstrated; a radio-station signal is suppressed by a factor of 20 without degradation to the signal of interest. With these compact sensors, in which the probe beam passes through twice, the fundamental limit to detection sensitivity is found to be photon-shot noise. More passes of the probe beam overcome this limitation. With a sensor of similar effective volume, 0.25 cm3 , but 25 × more passes, the sensitivity is improved by an order of magnitude to 1.7 ±0.2 fT /√{Hz } .
Nuclear-Spin Gyroscope Based on an Atomic Co-Magnetometer
Romalis, Michael; Komack, Tom; Ghost, Rajat
2008-01-01
An experimental nuclear-spin gyroscope is based on an alkali-metal/noblegas co-magnetometer, which automatically cancels the effects of magnetic fields. Whereas the performances of prior nuclear-spin gyroscopes are limited by sensitivity to magnetic fields, this gyroscope is insensitive to magnetic fields and to other external perturbations. In addition, relative to prior nuclear-spin gyroscopes, this one exhibits greater sensitivity to rotation. There is commercial interest in development of small, highly sensitive gyroscopes. The present experimental device could be a prototype for development of nuclear spin gyroscopes suitable for navigation. In comparison with fiber-optic gyroscopes, these gyroscopes would draw less power and would be smaller, lighter, more sensitive, and less costly.
Optically-Modulated Miniature Magnetometer (OMMM) Project
National Aeronautics and Space Administration — Design, fabricate, and calibrate a compact helium magnetometer for high-accuracy measurements of Earth’s magnetic field Provide vector and scalar measurements...
All optical vector magnetometer Project
National Aeronautics and Space Administration — This Phase I research project will investigate a novel method of operating an atomic magnetometer to simultaneously measure total magnetic fields and vector magnetic...
Ellmeier, M.; Hagen, C.; Piris, J.; Lammegger, R.; Jernej, I.; Woschank, M.; Magnes, W.; Murphy, E.; Pollinger, A.; Erd, C.; Baumjohann, W.; Windholz, L.
2018-02-01
We performed an endurance test with single-mode vertical-cavity surface-emitting lasers (VCSEL) under vacuum condition and increased operational parameters (laser current and laser temperature) to accelerate the aging of the lasers. During the endurance test the emitted polarization-dependent and polarization-independent optical light power from the lasers was detected. Additionally, electro-optical characterisations including measurements of the combination of laser current and laser temperature to excite the 87Rb D1 transition ( λ = 795 nm), the current and temperature tuning coefficients, laser line width, threshold current and the polarization ellipse were performed for the aged lasers. The test was started with a number of 12 VCSELs consisting of 4 lasers each from 3 different suppliers. The aging behaviour of VCSELs was investigated with respect to the development of a new optical magnetometer prototype for space missions with a mission duration of up to 17 years. Only a limited change of the electro-optical parameters can be tolerated by the instrument design over the mission duration. The endurance test and the electro-optical characterizations revealed clear differences in the aging behaviour of the three suppliers. Lasers from one supplier showed that they can be operated for more than 17 years under vacuum conditions without major degradation of their operational parameters.
Wu, T.; Peng, X.; Lin, Z.; Guo, H.
2015-10-01
We demonstrate an all-optical 4He atomic magnetometer experimental scheme based on an original Bell-Bloom configuration. A single intensity-modulated linearly polarized laser beam is used both for generating spin polarization within a single 4He vapor and probing the spin precessing under a static magnetic field. The transmitted light signal from the vapor is then phase-sensitively detected at the modulation frequency and its harmonics, which lead to the atomic magnetic resonance signals. Based on this structure, a liquid crystal is added in our magnetometer system and constitutes a polarization rotator. By controlling the voltage applied on the liquid crystal, the light linear polarization vector can be kept perpendicular with the ambient magnetic field direction, which in turn provides the maximum resonance signal amplitude. Moreover, the system exhibits a magnetic-field noise floor of about 2 pT / √{ Hz } , which is not degraded due to the presence of the liquid crystal and varying magnetic field direction. The experiment results prove that our method can eliminate the dead-zone effect, improve the system spatial isotropy, and thus be suitable in mobile applications.
Wu, T; Peng, X; Lin, Z; Guo, H
2015-10-01
We demonstrate an all-optical (4)He atomic magnetometer experimental scheme based on an original Bell-Bloom configuration. A single intensity-modulated linearly polarized laser beam is used both for generating spin polarization within a single (4)He vapor and probing the spin precessing under a static magnetic field. The transmitted light signal from the vapor is then phase-sensitively detected at the modulation frequency and its harmonics, which lead to the atomic magnetic resonance signals. Based on this structure, a liquid crystal is added in our magnetometer system and constitutes a polarization rotator. By controlling the voltage applied on the liquid crystal, the light linear polarization vector can be kept perpendicular with the ambient magnetic field direction, which in turn provides the maximum resonance signal amplitude. Moreover, the system exhibits a magnetic-field noise floor of about 2pT/√Hz, which is not degraded due to the presence of the liquid crystal and varying magnetic field direction. The experiment results prove that our method can eliminate the dead-zone effect, improve the system spatial isotropy, and thus be suitable in mobile applications.
Searching for axion stars and Q-balls with a terrestrial magnetometer network
Energy Technology Data Exchange (ETDEWEB)
Jackson Kimball, D. F. [Cal State, East Bay; Budker, D. [UC, Berkeley; Eby, J. [Fermilab; Pospelov, M. [Perimeter Inst. Theor. Phys.; Pustelny, S. [Jagiellonian U.; Scholtes, T. [Fribourg U.; Stadnik, Y. V. [Helmholtz Inst., Mainz; Weis, A. [Fribourg U.; Wickenbrock, A. [Mainz U.
2017-10-11
Light (pseudo-)scalar fields are promising candidates to be the dark matter in the Universe. Under certain initial conditions in the early Universe and/or with certain types of self-interactions, they can form compact dark-matter objects such as axion stars or Q-balls. Direct encounters with such objects can be searched for by using a global network of atomic magnetometers. It is shown that for a range of masses and radii not ruled out by existing observations, the terrestrial encounter rate with axion stars or Q-balls can be sufficiently high (at least once per year) for a detection. Furthermore, it is shown that a global network of atomic magnetometers is sufficiently sensitive to pseudoscalar couplings to atomic spins so that a transit through an axion star or Q-ball could be detected over a broad range of unexplored parameter space.
Energy Technology Data Exchange (ETDEWEB)
Huang, Zhiming, E-mail: 465609785@qq.com [School of Economics and Management, Wuyi University, Jiangmen 529020 (China); Situ, Haozhen, E-mail: situhaozhen@gmail.com [College of Mathematics and Informatics, South China Agricultural University, Guangzhou 510642 (China)
2017-02-15
In this article, the dynamics of quantum correlation and coherence for two atoms interacting with a bath of fluctuating massless scalar field in the Minkowski vacuum is investigated. We firstly derive the master equation that describes the system evolution with initial Bell-diagonal state. Then we discuss the system evolution for three cases of different initial states: non-zero correlation separable state, maximally entangled state and zero correlation state. For non-zero correlation initial separable state, quantum correlation and coherence can be protected from vacuum fluctuations during long time evolution when the separation between the two atoms is relatively small. For maximally entangled initial state, quantum correlation and coherence overall decrease with evolution time. However, for the zero correlation initial state, quantum correlation and coherence are firstly generated and then drop with evolution time; when separation is sufficiently small, they can survive from vacuum fluctuations. For three cases, quantum correlation and coherence first undergo decline and then fluctuate to relatively stable values with the increasing distance between the two atoms. Specially, for the case of zero correlation initial state, quantum correlation and coherence occur periodically revival at fixed zero points and revival amplitude declines gradually with increasing separation of two atoms.
In-flight scalar calibration and characterisation of the Swarm magnetometry package
DEFF Research Database (Denmark)
Tøffner-Clausen, Lars; Lesur, Vincent; Olsen, Nils
2016-01-01
We present the in-flight scalar calibration and characterisation of the Swarm magnetometry package consisting of the absolute scalar magnetometer, the vector magnetometer, and the spacecraft structure supporting the instruments. A significant improvement in the scalar residuals between the pairs ...
A phaseonium magnetometer: A new optical magnetometer based on index enhanced media
Scully, Marlan O.; Fleischauer, Michael; Graf, Martin
1993-01-01
An optical magnetometer based on quantum coherence and interference effects in atoms is proposed. The sensitivity of this device is potentially superior to the present state-of-the-art devices. Optimum operating conditions are derived, and a comparison to standard optical pumping magnetometers is made.
Augenbraun, Benjamin L; Rupasinghe, P M; Majumder, P K
2016-01-01
We have completed a measurement of the Stark shift within the $^{115}$In $6s_{1/2} \\rightarrow 6p_{1/2}$ excited-state transition using two-step laser spectroscopy in an indium atomic beam. Combining this measurement with recent experimental results we determine the scalar polarizability, $\\alpha_{0}$, of the $6p_{1/2}$ state to be $7683 \\pm43 \\,a_{0}^{3}$ in atomic units, a result which agrees very well with recent theoretical calculations. In this experiment, one laser, stabilized to the $5p_{1/2} \\rightarrow 6s_{1/2}$ 410~nm transition, was directed transversely to the atomic beam, while a second, overlapping laser was scanned across the 1343~nm $6s_{1/2} \\rightarrow 6p_{1/2}$ transition. We utilized two-tone frequency-modulation spectroscopy of the infrared laser beam to measure the second-step absorption in the interaction region, where the optical depth is less than 10$^{-3}$. In the course of our experimental work we also determined the hyperfine splitting within the $6p_{1/2}$ state, improving upon th...
Ørsted Pre-Flight Magnetometer Calibration Mission
DEFF Research Database (Denmark)
Risbo, T.; Brauer, Peter; Merayo, José M.G.
2003-01-01
modelling was developed and tested over several years and used for circle dividersted and other missions at test facilities in Europe, the United States and the Republic of South Africa. The verification of the test coil system using an Overhauser absolute scalar proton magnetometer is explained...
GOES Space Environment Monitor, Magnetometer
National Oceanic and Atmospheric Administration, Department of Commerce — Three orthogonal flux-gate magnetometer elements, (spinning twin fluxgate magnetometer prior to GOES-8) provide magnetic field measurements in three mutually...
All-optical, Three-axis Fiber Laser Magnetometer
2012-04-16
force acting on a current carrying bridge in the presence of a magnetic field, which drives its oscillation measured with a fiber laser strain sensor... strain between two cores as a function of rotation for difference inclinations and (b) reported inclination vs. actual inclination for a bend angle of...such as those based on SQUIDS, giant magnetoresistance (GMR), scalar resonance magnetometers, and flux-gates; however, a fiber optic sensor enables
THOR Fluxgate Magnetometer (MAG)
Nakamura, Rumi; Eastwood, Jonathan; Magnes, Werner; Carr, Christopher, M.; O'Brien, Helen, L.; Narita, Yasuhito; K, Chen, Christopher H.; Berghofer, Gerhard; Valavanoglou, Aris; Delva, Magda; Plaschke, Ferdinand; Cupido, Emanuele; Soucek, Jan
2017-04-01
Turbulence Heating ObserveR (THOR) is the first mission ever flown in space dedicated to plasma turbulence. The fluxgate Magnetometer (MAG) measures the background to low frequency magnetic field. The high sensitivity measurements of MAG enable to characterize the nature of turbulent fluctuations as well as the large-scale context. MAG will provide the reference system for determining anisotropy of field fluctuations, pitch-angle and gyro-phase of particles. The design of the magnetometer consists of two tri-axial sensors and the related magnetometer electronics; the electronics are hosted on printed circuit boards in the common electronics box of the fields and wave processor (FWP). A fully redundant two- sensor system mounted on a common boom and the new miniaturized low noise design based on MMS and Solar Orbiter instruments enable accurate measurement throughout the region of interest for THOR science. The usage of the common electronics hosted by FWP guarantees to fulfill the required timing accuracy with other fields measurements. These improvements are important to obtain precise measurements of magnetic field, which is essential to estimate basic plasma parameters and correctly identify the spatial and temporal scales of the turbulence. Furthermore, THOR MAG provides high quality data with sufficient overlap with the Search Coil Magnetometer (SCM) in frequency space to obtain full coverage of the wave forms over all the frequencies necessary to obtain the full solar wind turbulence spectrum from MHD to kinetic range with sufficient accuracy. We discuss the role of MAG in THOR key science questions and present the new developments during Phase A such as the finalised instrument design, MAG relevant requirement, and new calibraion schemes.
CASSINI SCALAR MAGNETOMETER CALIB DATA V1.0
National Aeronautics and Space Administration — This data set contains magnetic-field data acquired during the cruise and tour phases of the Cassini mission to Saturn. Data collection began on 16 August (day 228),...
DEFF Research Database (Denmark)
Hulot, Gauthier; Vigneron, Pierre; Leger, Jean-Michel
2015-01-01
readings of the magnetic eld. Since launch, these ASMs provided very high accuracy scalar eld data, as nominally required for the mission, together with experimental vector eld data. Here, we compare geomagnetic eld models built from such ASM-only data with models built from the mission's nominal 1Hz data......, combining ASM scalar data with independent uxgate magnetometer vector data. The high level of agreement between these models demonstrates the potential of the ASM's vector mode for data quality control and as a stand alone magnetometer, and illustrates the way the evolution of key eld features can easily...
The absolute magnetometers on board Swarm, lessons learned from more than two years in space
DEFF Research Database (Denmark)
Hulot, Gauthier; Leger, Jean-Michel; Vigneron, Pierre
ESA's Swarm satellites carry 4He absolute magnetometers (ASM), designed by CEA-Léti and developed in partnership with CNES. These instruments are the first-ever space-borne magnetometers to use a common sensor to simultaneously deliver 1Hz independent absolute scalar and vector readings of the ma......ESA's Swarm satellites carry 4He absolute magnetometers (ASM), designed by CEA-Léti and developed in partnership with CNES. These instruments are the first-ever space-borne magnetometers to use a common sensor to simultaneously deliver 1Hz independent absolute scalar and vector readings...... of the magnetic field. They have provided the very high accuracy scalar field data nominally required by the mission (for both science and calibration purposes, since each satellite also carries a low noise high frequency fluxgate magnetometer designed by DTU), but also very useful experimental absolute vector...... the advantages of flying ASM instruments on space-borne magnetic missions for data quality checks, geomagnetic field modeling and science objectives....
Optically transduced MEMS magnetometer
Nielson, Gregory N; Langlois, Eric
2014-03-18
MEMS magnetometers with optically transduced resonator displacement are described herein. Improved sensitivity, crosstalk reduction, and extended dynamic range may be achieved with devices including a deflectable resonator suspended from the support, a first grating extending from the support and disposed over the resonator, a pair of drive electrodes to drive an alternating current through the resonator, and a second grating in the resonator overlapping the first grating to form a multi-layer grating having apertures that vary dimensionally in response to deflection occurring as the resonator mechanically resonates in a plane parallel to the first grating in the presence of a magnetic field as a function of the Lorentz force resulting from the alternating current. A plurality of such multi-layer gratings may be disposed across a length of the resonator to provide greater dynamic range and/or accommodate fabrication tolerances.
GALILEO MAGNETOMETER CRUISE EDR DATA
National Aeronautics and Space Administration — This data set contains data acquired by the Galileo Magnetometer during the Interplanetary Cruise to Jupiter. The data are at varying resolution depending on the...
Miniature Laser Magnetometer (MLM) Project
National Aeronautics and Space Administration — This 2009 NASA SBIR Phase 2 proposal for an innovative Miniature Laser Magnetometer (MLM) is a response to subtopic S1.06 Particles and Field Sensors and Instrument...
Miniature Laser Magnetometer (MLM) Project
National Aeronautics and Space Administration — This 2009 NASA SBIR Phase 1 proposal for an innovative Miniature Laser Magnetometer (MLM) is a response to subtopic S1.06 Particles and Field Sensors and Instrument...
Microfabricated optically pumped magnetometer arrays for biomedical imaging
Perry, A. R.; Sheng, D.; Krzyzewski, S. P.; Geller, S.; Knappe, S.
2017-02-01
Optically-pumped magnetometers have demonstrated magnetic field measurements as precise as the best superconducting quantum interference device magnetometers. Our group develops miniature alkali atom-based magnetic sensors using microfabrication technology. Our sensors do not require cryogenic cooling, and can be positioned very close to the sample, making these sensors an attractive option for development in the medical community. We will present our latest chip-scale optically-pumped gradiometer developed for array applications to image magnetic fields from the brain noninvasively. These developments should lead to improved spatial resolution, and potentially sensitive measurements in unshielded environments.
Atomic Magnetometry in the Lab, in the Field, and in the Sky
Patton, B.; Versolato, O.; Hovde, C.; Rochester, S.; Higbie, J.; Budker, D.
2012-12-01
Atomic magnetometers [1] have played an important role in geophysical research ever since their advent more than fifty years ago. They have been used in near-surface magnetic surveys, aboard ionospheric sounding rockets, and have been critical in satellite missions dedicated to precise geophysical field mapping [2]. Over the past decade, renewed interest in atomic magnetometers has led to dramatically improved sensitivity in laboratory devices. The best alkali-vapor magnetometers, operating in magnetically shielded low-field environments, can now achieve sensitivities better than 1 femtotesla in a one-second measurement [3]. The precision of atomic magnetometers operating at Earth's field, on the other hand, has lagged in comparison. We will review recent efforts to achieve better sensitivity and accuracy in all-optical alkali-vapor magnetometers operating in geophysical field ranges. Advances in laser technology, antirelaxation vapor-cell coatings [4], and optical pumping techniques have resulted in better fundamental precision and dramatically reduced systematic error in these devices. The result is a new generation of compact, low-cost, and low-power sensors which are well suited for geophysical research. In addition to these developments, we will also discuss the potential for fully remote atom-based magnetic measurements [5]. This includes a proposed scheme to measure the magnetic field within the mesospheric sodium layer using existing laser guide star technology [6]. This technique would allow magnetic surveying at length and time scales heretofore inaccessible, and would yield data relevant to magnetic anomaly mapping, ionospheric physics, ocean circulation models, and lithospheric magnetization studies. [1] Budker, D., and M. Romalis (2007), Optical magnetometry, Nat. Phys., 3(4), 227-234. [2] Ravat, D., et al. (1995), Global vector and scalar Magsat magnetic anomaly maps, J. Geophys. Res.-Solid Earth, 100(B10), 20111-20136. [3] Dang, H. B., et al. (2010
Magnetogama: an open schematic magnetometer
Wahyudi; Khakhim, Nurul; Kuntoro, Tri; Mardiatno, Djati; Rakhman, Afif; Setyo Handaru, Anas; Akhmad Mufaqih, Adien; Marwan Irnaka, Theodosius
2017-09-01
Magnetogama is an open schematic hand-assembled fluxgate magnetometer. Compared to another magnetometer, Magnetogama has more benefit concerning its price and its ease of use. Practically Magnetogama can be utilized either in land or attached to an unmanned aerial vehicle (UAV). Magnetogama was designed to give open access to a cheap and accurate alternative to magnetometer sensor. Therefore it can be used as a standard design which is directly applicable to the low-budget company or education purposes. Schematic, code and several verification tests were presented in this article ensuring its reproducibility. Magnetogama has been tested with two kind of tests: a comparison with two nearest observatories at Learmonth (LRM) and Kakadu (KDU) and the response of magnetic substance.
Kleihaus, Burkhard; Yazadjiev, Stoytcho
2015-01-01
In the presence of a complex scalar field scalar-tensor theory allows for scalarized rotating hairy black holes. We exhibit the domain of existence for these scalarized black holes, which is bounded by scalarized rotating boson stars and ordinary hairy black holes. We discuss the global properties of these solutions. Like their counterparts in general relativity, their angular momentum may exceed the Kerr bound, and their ergosurfaces may consist of a sphere and a ring, i.e., form an ergo-Saturn.
Achasov, N. N.; Kiselev, A. V.; Shestakov, G. N.
2008-01-01
Outline: 1. Introduction, 2. Confinement, chiral dynamics and light scalar mesons, 3. Chiral shielding of the \\sigma(600), chiral constraints (the CGL band), the \\sigma(600) and the f0(980) in \\pi\\pi->\\pi\\pi, \\pi\\pi->KKbar, \\phi->\\gamma\\pi0\\pi0, 4. The \\phi meson radiative decays on light scalar resonances, 5. Light scalars in \\gamma\\gamma collisions. Evidence for four-quark components of light scalars is given. The priority of Quantum Field Theory in revealing the light scalar mystery is emp...
The low cost Proton Precession Magnetometer developed at the Indian Institute of Geomagnetism
Mahavarkar, P.; Singh, S.; Labde, S.; Dongre, V.; Patil, A.
2017-05-01
Proton magnetometers are the oldest scalar magnetometers. The first commercial units were produced in early 1960s as portable instruments. In continuation airborne instruments appeared with optimized speed of readings and sensitivity, large sensors etc. Later development of Overhauser and optically pumped magnetometers has eliminated Proton magnetometers from airborne surveys. However they remain very popular in various ground surveys and observatories. With this primary purpose of generating the ground based magnetic data, the Indian Institute of Geomagnetism (IIG) for the last 3 decades have been developing low cost Proton Precession Magnetometers (PPM). Beginning with the 1 nT PPM which has undergone several changes in design, the successor PM7 the advanced version has been successfully developed by the institute and is installed at various observatories of the institute. PM7 records the total field `F' with accuracy of 0.1 nT and a sampling rate of 10 seconds/sample. This article briefly discusses the design and development of this IIG make PM7 and compares the data recorded by this instrument with one of the commercially available Overhauser magnetometer in the world market. The quality of data recorded by PM7 is in excellent agreement with the Overhauser. With the available quality of data generated by this instrument, PM7 is an affordable PPM for scientific institutions, schools and colleges intending to carry out geomagnetic studies. The commercial cost of PM7 is ≈ 20% of the cost of Overhauser available in market.
McCaughey, Mike
2017-01-01
An Arduino-based system with a triple axis magnetometer chip may be used to plot both the strength and direction of the magnetic field of a magnet directly on a sheet of paper. Before taking measurements, it is necessary either to correct for or to eliminate soft and hard iron effects. The same sensor may be used to determine the presence of soft…
Energy Technology Data Exchange (ETDEWEB)
Kleihaus, Burkhard, E-mail: b.kleihaus@uni-oldenburg.de [Institut für Physik, Universität Oldenburg, Postfach 2503, D-26111 Oldenburg (Germany); Kunz, Jutta [Institut für Physik, Universität Oldenburg, Postfach 2503, D-26111 Oldenburg (Germany); Yazadjiev, Stoytcho [Department of Theoretical Physics, Faculty of Physics, Sofia University, Sofia 1164 (Bulgaria)
2015-05-11
In the presence of a complex scalar field scalar–tensor theory allows for scalarized rotating hairy black holes. We exhibit the domain of existence for these scalarized black holes, which is bounded by scalarized rotating boson stars and hairy black holes of General Relativity. We discuss the global properties of these solutions. Like their counterparts in general relativity, their angular momentum may exceed the Kerr bound, and their ergosurfaces may consist of a sphere and a ring, i.e., form an ergo-Saturn.
Directory of Open Access Journals (Sweden)
Burkhard Kleihaus
2015-05-01
Full Text Available In the presence of a complex scalar field scalar–tensor theory allows for scalarized rotating hairy black holes. We exhibit the domain of existence for these scalarized black holes, which is bounded by scalarized rotating boson stars and hairy black holes of General Relativity. We discuss the global properties of these solutions. Like their counterparts in general relativity, their angular momentum may exceed the Kerr bound, and their ergosurfaces may consist of a sphere and a ring, i.e., form an ergo-Saturn.
Induction Magnetometers – Design Peculiarities
Directory of Open Access Journals (Sweden)
Valeriy KOREPANOV
2010-09-01
Full Text Available Induction or search-coil magnetometers (IM are widely used in many branches of science and industry. The frequency range and dynamic range of IMs are probably the widest of all existing magnetometers: they are used for the measurement of magnetic field variations in the frequency band from ~10-4 till ~106 Hz with the intensities from fractions of femtotesla till tens of tesla. This explains the permanent interest to IM design and the attempts to construct the IMs with best possible parameters. The present paper deals with the peculiarities of IM design. An attempt to re-establish the correctness of priorities in the field is made and the approaches to the IM optimization and their quality estimation are described.
A rubidium Mx-magnetometer for measurements on solid state spins
Arnold, Daniel; Siegel, Steven; Grisanti, Emily; Wrachtrup, Jörg; Gerhardt, Ilja
2017-02-01
The detection of environmental magnetic fields is well established by optically pumped atomic magnetometers. Another focus of magnetometry can be the research on magnetic or spin-active solid-state samples. Here we introduce a simple and compact design of a rubidium-based Mx magnetometer, which allows for hosting solid-state samples. The optical, mechanical, and electrical design is reported, as well as simple measurements which introduce the ground-state spin-relaxation time, the signal-to-noise ratio of a measurement, and subsequently the overall sensitivity of the magnetometer. The magnetometer is optimized for the most sensitive operation with respect to laser power and magnetic field excitation at the Larmor frequency.
A rubidium Mx-magnetometer for measurements on solid state spins.
Arnold, Daniel; Siegel, Steven; Grisanti, Emily; Wrachtrup, Jörg; Gerhardt, Ilja
2017-02-01
The detection of environmental magnetic fields is well established by optically pumped atomic magnetometers. Another focus of magnetometry can be the research on magnetic or spin-active solid-state samples. Here we introduce a simple and compact design of a rubidium-based Mx magnetometer, which allows for hosting solid-state samples. The optical, mechanical, and electrical design is reported, as well as simple measurements which introduce the ground-state spin-relaxation time, the signal-to-noise ratio of a measurement, and subsequently the overall sensitivity of the magnetometer. The magnetometer is optimized for the most sensitive operation with respect to laser power and magnetic field excitation at the Larmor frequency.
Composite Rolled Magnetometer and Instrument Boom Project
National Aeronautics and Space Administration — Magnetometers are the most common instrument flown on NASA science missions and interference from onboard electronics requires that these instruments be deployed...
Nuclear quantum-assisted magnetometer
Häberle, Thomas; Oeckinghaus, Thomas; Schmid-Lorch, Dominik; Pfender, Matthias; de Oliveira, Felipe Fávaro; Momenzadeh, Seyed Ali; Finkler, Amit; Wrachtrup, Jörg
2017-01-01
Magnetic sensing and imaging instruments are important tools in biological and material sciences. There is an increasing demand for attaining higher sensitivity and spatial resolution, with implementations using a single qubit offering potential improvements in both directions. In this article we describe a scanning magnetometer based on the nitrogen-vacancy center in diamond as the sensor. By means of a quantum-assisted readout scheme together with advances in photon collection efficiency, our device exhibits an enhancement in signal to noise ratio of close to an order of magnitude compared to the standard fluorescence readout of the nitrogen-vacancy center. This is demonstrated by comparing non-assisted and assisted methods in a T1 relaxation time measurement.
A ocean bottom vector magnetometer
Wang, Xiaomei; Teng, Yuntian; Wang, Chen; Ma, Jiemei
2017-04-01
The new development instrument with a compact spherical coil system and Overhauser magnetometer for measuring the total strength of the magnetic field and the vectors of strength, Delta inclination - Delta declination, meanwhile we also use a triaxial fluxgate instrument of the traditional instrument for geomagnetic vector filed measurement. The advantages of this method are be calibrated by each other and get good performances with automatic operation, good stability and high resolution. Firstly, a brief description of the instrument measurement principles and the key technologies are given. The instrument used a spherical coil system with 34 coils to product the homogeneous volume inside the coils which is large enough to accommodate the sensor of Overhauser total field sensor; the rest of the footlocker-sized ocean-bottom vector magnetometer consists of equipment to run the sensors and records its data (batteries and a data logger), weight to sink it to the sea floor, a remote-controlled acoustic release and flotation to bring the instrument back to the surface. Finally, the accuracy of the instrument was tested in the Geomagnetic station, and the measurement accuracies of total strength and components were better than 0.2nT and 1nT respectively. The figure 1 shows the development instrument structure. it includes six thick glass spheres which protect the sensor, data logger and batteries from the pressures of the deep sea, meanwhile they also provide recycling positive buoyancy; To cushion the glass, the spheres then go inside yellow plastic "hardhats". The triaxial fluxgate is inside No.1 glass spheres, data logger and batteries are inside No.2 glass spheres, the new vector sensor is inside No.3 glass spheres, acoustic communication unit is inside No.4 glass spheres, No.5 and No.6 glass spheres are empty which only provide recycling positive buoyancy. The figure 2 shows the development instrument Physical photo.
Energy Technology Data Exchange (ETDEWEB)
Rejon-Barrera, Fernando [Institute for Theoretical Physics, University of Amsterdam,Science Park 904, Postbus 94485, 1090 GL, Amsterdam (Netherlands); Robbins, Daniel [Department of Physics, Texas A& M University,TAMU 4242, College Station, TX 77843 (United States)
2016-01-22
We work out all of the details required for implementation of the conformal bootstrap program applied to the four-point function of two scalars and two vectors in an abstract conformal field theory in arbitrary dimension. This includes a review of which tensor structures make appearances, a construction of the projectors onto the required mixed symmetry representations, and a computation of the conformal blocks for all possible operators which can be exchanged. These blocks are presented as differential operators acting upon the previously known scalar conformal blocks. Finally, we set up the bootstrap equations which implement crossing symmetry. Special attention is given to the case of conserved vectors, where several simplifications occur.
Stochastic inflationary scalar electrodynamics
Prokopec, T.; Tsamis, N.C.; Woodard, R.P.
2008-01-01
We stochastically formulate the theory of scalar quantum electrodynamics on a de Sitter background. This reproduces the leading infrared logarithms at each loop order. It also allows one to sum the series of leading infrared logarithms to obtain explicit, nonperturbative results about the late time
Magnetometer Data recovered from 35mm film
National Oceanic and Atmospheric Administration, Department of Commerce — The L57 CDMP recovery project takes magnetometer data on 35mm film stored at the archive's climate controlled warehouse and digitizes them.
GALILEO MAGNETOMETER CRUISE DATA (RTN COORDINATES)
National Aeronautics and Space Administration — This dataset contains data acquired by the Galileo Magnetometer during the Interplanetary Cruise to Jupiter. The data are at varying resolution depending on the...
Digital Detection and feedback Fluxgate Magnetometer
DEFF Research Database (Denmark)
Piil-Henriksen, J.; Merayo, José M.G.; Nielsen, Otto V
1996-01-01
A new full Earth's field dynamic feedback fluxgate magnetometer is described. It is based entirely on digital signal processing and digital feedback control, thereby replacing the classical second harmonic tuned analogue electronics by processor algorithms. Discrete mathematical cross...
National Aeronautics and Space Administration — These data were obtained from the JPL magnetometer experiment on ICE (Principal Investigator: E.J. Smith produces three, high-accuracy, triaxial measurements per...
Cryogenic pulsed inductive microwave magnetometer
Kos, A. B.; Nibarger, J. P.; Lopusnik, R.; Silva, T. J.; Celinski, Z.
2003-05-01
A cryogenic pulsed inductive microwave magnetometer is used to characterize the switching dynamics in thin-film magnetic materials at low temperatures and microwave frequencies. The system is contained inside a 20-cm-diam ultrahigh vacuum chamber and cooled by a cryopump that allows measurements between 20 and 350 K. A temperature controller regulates the sample temperature using two silicon diodes as sensors. Applied magnetic fields of up to 36 kA/m (450 Oe) are generated by a four-pole, water-cooled electromagnet with independent control of each axis. Magnetic switching in the sample is driven by high-speed current step pulses in a coplanar waveguide structure with the sample placed in a flip-chip configuration. A 20 GHz sampling oscilloscope is used to record the dynamics of the magnetic reorientation. The switching dynamics are given for a 10-nm-thick Ni-Fe film at 30 K in response to a 1 kA/m field step.
CMB bounds on tensor-scalar-scalar inflationary correlations
Shiraishi, Maresuke; Liguori, Michele; Fergusson, James R.
2018-01-01
The nonlinear interaction between one graviton and two scalars is enhanced in specific inflationary models, potentially leading to distinguishable signatures in the bispectrum of the cosmic microwave background (CMB) anisotropies. We develop the tools to examine such bispectrum signatures, and show a first application using WMAP temperature data. We consider several l-ranges, estimating the gtss amplitude parameter, by means of the so-called separable modal methodology. We do not find any evidence of a tensor-scalar-scalar signal at any scale. Our tightest bound on the size of the tensor-scalar-scalar correlator is derived from our measurement including all the multipoles in the range 2 first direct observational constraint on the primordial tensor-scalar-scalar correlation, and it will be cross-checked and improved by applying the same pipeline to high-resolution temperature and polarization data from Planck and forthcoming CMB experiments.
Bittencourt, E; Novello, M; Toniato, J D
2016-01-01
We discuss a class of models for gravity based on a scalar field. The models include and generalize the old approach by Nordstr\\"om which predated and in some way inspired General Relativity. The class include also a model that we have recently introduced and discussed in its cosmological aspects (GSG). We present here a complete characterisation of the Schwarschild geometry as a vacuum solution of GSG and sketch a discussion of the first Post-Newtonian approximation.
Search for scalar top and scalar bottom quarks at LEP
Abbiendi, G.; Akesson, P.F.; Alexander, G.; Allison, John; Amaral, P.; Anagnostou, G.; Anderson, K.J.; Arcelli, S.; Asai, S.; Axen, D.; Azuelos, G.; Bailey, I.; Barberio, E.; Barlow, R.J.; Batley, R.J.; Bechtle, P.; Behnke, T.; Bell, Kenneth Watson; Bell, P.J.; Bella, G.; Bellerive, A.; Benelli, G.; Bethke, S.; Biebel, O.; Bloodworth, I.J.; Boeriu, O.; Bock, P.; Bonacorsi, D.; Boutemeur, M.; Braibant, S.; Brigliadori, L.; Brown, Robert M.; Buesser, K.; Burckhart, H.J.; Campana, S.; Carnegie, R.K.; Caron, B.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, David G.; Csilling, A.; Cuffiani, M.; Dado, S.; Dallavalle, G.Marco; Dallison, S.; De Roeck, A.; De Wolf, E.A.; Desch, K.; Dienes, B.; Donkers, M.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Elfgren, E.; Etzion, E.; Fabbri, F.; Feld, L.; Ferrari, P.; Fiedler, F.; Fleck, I.; Ford, M.; Frey, A.; Furtjes, A.; Gagnon, P.; Gary, John William; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Giunta, Marina; Goldberg, J.; Gross, E.; Grunhaus, J.; Gruwe, M.; Gunther, P.O.; Gupta, A.; Hajdu, C.; Hamann, M.; Hanson, G.G.; Harder, K.; Harel, A.; Harin-Dirac, M.; Hauschild, M.; Hauschildt, J.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Hensel, C.; Herten, G.; Heuer, R.D.; Hill, J.C.; Hoffman, Kara Dion; Homer, R.J.; Horvath, D.; Howard, R.; Huntemeyer, P.; Igo-Kemenes, P.; Ishii, K.; Jeremie, H.; Jovanovic, P.; Junk, T.R.; Kanaya, N.; Kanzaki, J.; Karapetian, G.; Karlen, D.; Kartvelishvili, V.; Kawagoe, K.; Kawamoto, T.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Kim, D.H.; Klein, K.; Klier, A.; Kluth, S.; Kobayashi, T.; Kobel, M.; Komamiya, S.; Kormos, Laura L.; Kowalewski, Robert V.; Kramer, T.; Kress, T.; Krieger, P.; von Krogh, J.; Krop, D.; Kruger, K.; Kupper, M.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Layter, J.G.; Leins, A.; Lellouch, D.; Letts, J.; Levinson, L.; Lillich, J.; Lloyd, S.L.; Loebinger, F.K.; Lu, J.; Ludwig, J.; Macpherson, A.; Mader, W.; Marcellini, S.; Marchant, T.E.; Martin, A.J.; Martin, J.P.; Masetti, G.; Mashimo, T.; Mattig, Peter; McDonald, W.J.; McKenna, J.; McMahon, T.J.; McPherson, R.A.; Meijers, F.; Mendez-Lorenzo, P.; Menges, W.; Merritt, F.S.; Mes, H.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Moed, S.; Mohr, W.; Mori, T.; Mutter, A.; Nagai, K.; Nakamura, I.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oh, A.; Okpara, A.; Oreglia, M.J.; Orito, S.; Pahl, C.; Pasztor, G.; Pater, J.R.; Patrick, G.N.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poli, B.; Polok, J.; Pooth, O.; Przybycien, M.; Quadt, A.; Rabbertz, K.; Rembser, C.; Renkel, P.; Rick, H.; Roney, J.M.; Rosati, S.; Rozen, Y.; Runge, K.; Sachs, K.; Saeki, T.; Sahr, O.; Sarkisyan, E.K.G.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schoerner-Sadenius, Thomas; Schroder, Matthias; Schumacher, M.; Schwick, C.; Scott, W.G.; Seuster, R.; Shears, T.G.; Shen, B.C.; Shepherd-Themistocleous, C.H.; Sherwood, P.; Siroli, G.; Skuja, A.; Smith, A.M.; Sobie, R.; Soldner-Rembold, S.; Spagnolo, S.; Spano, F.; Stahl, A.; Stephens, K.; Strom, David M.; Strohmer, R.; Tarem, S.; Tasevsky, M.; Taylor, R.J.; Teuscher, R.; Thomson, M.A.; Torrence, E.; Toya, D.; Tran, P.; Trefzger, T.; Tricoli, A.; Trocsanyi, Z.; Tsur, E.; Turner-Watson, M.F.; Ueda, I.; Ujvari, B.; Vachon, B.; Vollmer, C.F.; Vannerem, P.; Verzocchi, M.; Voss, H.; Vossebeld, J.; Waller, D.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wengler, T.; Wermes, N.; Wetterling, D.; Wilson, G.W.; Wilson, J.A.; Wolf, G.; Wyatt, T.R.; Yamashita, S.; Zer-Zion, D.; Zivkovic, Lidija
2002-01-01
Searches for a scalar top quark and a scalar bottom quark have been performed using a data sample of 438 pb-1 at centre-of-mass energies of sqrt(s) = 192 - 209 GeV collected with the OPAL detector at LEP. No evidence for a signal was found. The 95% confidence level lower limit on the scalar top quark mass is 97.6 GeV if the mixing angle between the supersymmetric partners of the left- and right-handed states of the top quark is zero. When the scalar top quark decouples from the Z0 boson, the lower limit is 95.7 GeV. These limits were obtained assuming that the scalar top quark decays into a charm quark and the lightest neutralino, and that the mass difference between the scalar top quark and the lightest neutralino is larger than 10 GeV. The complementary decay mode of the scalar top quark decaying into a bottom quark, a charged lepton and a scalar neutrino has also been studied. The lower limit on the scalar top quark mass is 93.0 GeV for this decay mode, if the mass difference between the scalar top quark a...
Automatic magnetometer calibration with small space coverage
Wahdan, Ahmed
The use of a standalone Global Navigation Satellite System (GNSS) has proved to be insufficient when navigating indoors or in urban canyons due to multipath or obstruction. Recent technological advances in low cost micro-electro-mechanical system (MEMS) -- based sensors (like accelerometers, gyroscopes and magnetometers) enabled the development of sensor-based navigation systems. Although MEMS sensors are low-cost, lightweight, small size, and have low-power consumption, they have complex error characteristics. Accurate computation of the heading angle (azimuth) is one of the most important aspects of any navigation system. It can be computed either by gyroscopes or magnetometers. Gyroscopes are inertial sensors that can provide the angular rate from which the heading can be calculated, however, their outputs drift with time. Moreover, the accumulated errors due to mathematical integration, performed to obtain the heading angle, lead to large heading errors. On the other hand, magnetometers do not suffer from drift and the calculation of heading does not suffer from error accumulation. They can provide an absolute heading from the magnetic north by sensing the earth's magnetic field. However, magnetometer readings are usually affected by magnetic fields, other than the earth magnetic field, and by other error sources; therefore magnetometer calibration is required to use magnetometer as a reliable source of heading in navigation applications. In this thesis, a framework for fast magnetometer calibration is proposed. This framework requires little space coverage with no user involvement in the calibration process, and does not need specific movements to be performed. The proposed techniques are capable of performing both 2-dimensional (2D) and 3-dimensional (3D) calibration for magnetometers. They are developed to consider different scenarios suitable for different applications, and can benefit from natural device movements. Some applications involve tethering the
Spaced-based search coil magnetometers
Hospodarsky, George B.
2016-12-01
Search coil magnetometers are one of the primary tools used to study the magnetic component of low-frequency electromagnetic waves in space. Their relatively small size, mass, and power consumption, coupled with a good frequency range and sensitivity, make them ideal for spaceflight applications. The basic design of a search coil magnetometer consists of many thousands of turns of wire wound on a high permeability core. When a time-varying magnetic field passes through the coil, a time-varying voltage is induced due to Faraday's law of magnetic induction. The output of the coil is usually attached to a preamplifier, which amplifies the induced voltage and conditions the signal for transmission to the main electronics (usually a low-frequency radio receiver). Search coil magnetometers are usually used in conjunction with electric field antenna to measure electromagnetic plasma waves in the frequency range of a few hertz to a few tens of kilohertzs. Search coil magnetometers are used to determine the properties of waves, such as comparing the relative electric and magnetic field amplitudes of the waves, or to investigate wave propagation parameters, such as Poynting flux and wave normal vectors. On a spinning spacecraft, they are also sometimes used to determine the background magnetic field. This paper presents some of the basic design criteria of search coil magnetometers and discusses design characteristics of sensors flown on a number of spacecraft.
Rodríguez, Yeinzon; Navarro, Andrés A.
2017-03-01
An alternative for the construction of fundamental theories is the introduction of Galileons. These are fields whose action leads to non higher than second-order equations of motion. As this is a necessary but not sufficient condition to make the Hamiltonian bounded from below, as long as the action is not degenerate, the Galileon construction is a way to avoid pathologies both at the classical and quantum levels. Galileon actions are, therefore, of great interest in many branches of physics, specially in high energy physics and cosmology. This proceedings contribution presents the generalities of the construction of both scalar and vector Galileons following two different but complimentary routes.
DEFF Research Database (Denmark)
Sannino, Francesco
2016-01-01
We construct effective Lagrangians, and corresponding counting schemes, valid to describe the dynamics of the lowest lying large N stable massive composite state emerging in strongly coupled theories. The large N counting rules can now be employed when computing quantum corrections via an effective...... at the electroweak scale. To illustrate the formalism we consider the possibility that the Higgs emerges as: the lightest glueball of a new composite theory; the large N scalar meson in models of dynamical electroweak symmetry breaking; the large N pseudodilaton useful also for models of near-conformal dynamics...
Achasov, N. N.
2008-01-01
Outline: 1. Introduction, 2. Confinement, chiral dynamics and light scalar mesons, 3. Chiral shielding of \\sigma(600), chiral constraints, \\sigma(600), f_0(980) and their mixing in \\pi\\pi\\to\\pi\\pi, \\pi\\pi\\to K\\bar K, and \\phi\\to\\gamma\\pi0\\pi0, 4. The \\phi meson radiative decays on light scalar resonances. 5. Why a0(980) and f0(980) are not the K\\bar K molecules. 6. Light scalars in \\gamma\\gamma collisions. Evidence for four-quark components of light scalars is given. The priority of Quantum F...
Design and simulation of MEMS capacitive magnetometer
Jyoti, Aditi, Tripathi, C. C.; Gopal, Ram
2016-04-01
This paper presents the design and simulation of a MEMS Capacitive Magnetometer using FEM (Finite Element Method) tool COMSOL Multiphysics 4.3b and results from this simulation are closely matched with analytically calculated results. A comb drive structure is used for actuation purpose which operates at resonant frequency of device is 11.791 kHz to achieve maximum displacement. A magnetic field in z-axis can be detected by this comb drive structure. Quality factor of MEMS capacitive magnetometer obtained is 18 and it has good linear response in the magnetic field range of 100 µT.
Digitalization of highly precise fluxgate magnetometers
DEFF Research Database (Denmark)
Cerman, Ales; Kuna, A.; Ripka, P.
2005-01-01
allowing configurations with modulator inside and outside the feedback loop. The last principle is demonstrated on the project of the fully digital fluxgate magnetometer based on the digital signal processor (DSP). The results of the presented projects are compared with recently published competitive...
Electroweak Baryogenesis and Colored Scalars
Energy Technology Data Exchange (ETDEWEB)
Cohen, Timothy; /SLAC /Michigan U., MCTP; Pierce, Aaron; /Michigan U., MCTP
2012-02-15
We consider the 2-loop finite temperature effective potential for a Standard Model-like Higgs boson, allowing Higgs boson couplings to additional scalars. If the scalars transform under color, they contribute 2-loop diagrams to the effective potential that include gluons. These 2-loop effects are perhaps stronger than previously appreciated. For a Higgs boson mass of 115 GeV, they can increase the strength of the phase transition by as much as a factor of 3.5. It is this effect that is responsible for the survival of the tenuous electroweak baryogenesis window of the Minimal Supersymmetric Standard Model. We further illuminate the importance of these 2-loop diagrams by contrasting models with colored scalars to models with singlet scalars. We conclude that baryogenesis favors models with light colored scalars. This motivates searches for pair-produced di-jet resonances or jet(s) + = E{sub T}.
DEFF Research Database (Denmark)
Vigneron, Pierre; Hulot, Gauthier; Olsen, Nils
2015-01-01
Each of the three satellites of the European Space Agency Swarm mission carries an absolute scalar magnetometer (ASM) that provides the nominal 1-Hz scalar data of the mission for both science and calibration purposes. These ASM instruments, however, also deliver autonomous 1-Hz experimental vector...... geographical distribution of the selected data set (essentially due to a lack of availability of data at high northern latitude satisfying nighttime conditions at the end of the time period considered). These appear to be comparable to differences classically observed among IGRF candidate models...
Spin Squeezing and Entanglement with Room Temperature Atoms for Quantum Sensing and Communication
DEFF Research Database (Denmark)
Shen, Heng
magnetometer at room temperature is reported. Furthermore, using spin-squeezing of atomic ensemble, the sensitivity of magnetometer is improved. Deterministic continuous variable teleportation between two distant atomic ensembles is demonstrated. The fidelity of teleportating dynamically changing sequence...... of spin states surpasses a classical benchmark, demonstrating the true quantum teleportation....
Vector Magnetometer Application with Moving Carriers
Directory of Open Access Journals (Sweden)
Andrii Prystai
2016-12-01
Full Text Available In magnetic prospecting the aeromagnetic survey is a widespread method used for research in large territories or in the areas with difficult access (forests, swamps, shallow waters. At present, a new type of mobile carriers – remotely piloted vehicles or drones – is becoming very common. The drones supplied by magnetometer can be also used for underground utility location (for example, steel and concrete constructions, buried power cables, to name a few. For aeromagnetic survey, obtaining of 3-component magnetic field data gives higher processing precision, so the fluxgate magnetometers (FGM seem to be the most preferable by reason of low weight, noise, power consumption and costs. During movement of FGM fixed to a drone practically permanent attitude changes in the Earth’s magnetic field arises with corresponding changes of its projection at FGM axes. Also the electromagnetic interference from the drone motor and uncontrolled oscillations of drone and suspension are the factors which limit the magnetometer sensitivity level. Aroused because of this, signals significantly exceed the expected signals from a studied object and so should be removed by proper interference filtration and use of stabilized towed construction, as well as at data processing. To find the necessary resolution threshold of a drone-portable FGM, the modeling was made to estimate magnetic field value from a small sphere about 1 cm radius at the minimal altitude of drone flight and it was shown that such a small object can be reliably detected if the FGM noise level is less than 0.15 nT. Next requirement is the necessity to decrease as much as possible the FGM power consumption with retention of low noise level. Finally, because of drone movement, the broadening of a frequency range should be done. The LEMI-026 magnetometer was developed satisfying all requirements to the drone-mounted device. The field tests were successfully performed using two of LEMI-026
A Web Server for MACCS Magnetometer Data
Engebretson, Mark J.
1998-01-01
NASA Grant NAG5-3719 was provided to Augsburg College to support the development of a web server for the Magnetometer Array for Cusp and Cleft Studies (MACCS), a two-dimensional array of fluxgate magnetometers located at cusp latitudes in Arctic Canada. MACCS was developed as part of the National Science Foundation's GEM (Geospace Environment Modeling) Program, which was designed in part to complement NASA's Global Geospace Science programs during the decade of the 1990s. This report describes the successful use of these grant funds to support a working web page that provides both daily plots and file access to any user accessing the worldwide web. The MACCS home page can be accessed at http://space.augsburg.edu/space/MaccsHome.html.
Design, Construction, and Testing of MOKE Magnetometer
Bailey, Tighe; Miller, Casey W.
We report on the construction of a transverse magneto-optical Kerr effect (MOKE) magnetometer using various optical and electrical components. Uniquely, our MOKE magnetometer is able to sweep the magnetic field at frequencies greater than one Hz using lock in amplifiers to simultaneously sample the photodetector and the Hall sensor. The buffer of a lock-in amplifier allows for 512 samples per second, which allow us to rapidly sweep the magnetic field without loss of resolution. This drastically cuts down on the time taken per scan. To demonstrate the MOKE's capabilities, scans were performed on multiple thin film magnetic structures, both with and without significant magnetic anisotropy. We were able to measure room temperature hysteresis loops of ferromagnets, such as Ni80Fe20. Our sample rotation capabilities allowed us to study the angular dependence of the exchange and magnetocrystalline anisotropy in bilayer structures. Supported by NSF 1515677.
Calibration of Magnetometers with GNSS Receivers and Magnetometer-Aided GNSS Ambiguity Fixing.
Henkel, Patrick
2017-06-08
Magnetometers provide compass information, and are widely used for navigation, orientation and alignment of objects. As magnetometers are affected by sensor biases and eventually by systematic distortions of the Earth magnetic field, a calibration is needed. In this paper, a method for calibration of magnetometers with three Global Navigation Satellite System (GNSS) receivers is presented. We perform a least-squares estimation of the magnetic flux and sensor biases using GNSS-based attitude information. The attitude is obtained from the relative positions between the GNSS receivers in the North-East-Down coordinate frame and prior knowledge of these relative positions in the platform's coordinate frame. The relative positions and integer ambiguities of the periodic carrier phase measurements are determined with an integer least-squares estimation using an integer decorrelation and sequential tree search. Prior knowledge on the relative positions is used to increase the success rate of ambiguity fixing. We have validated the proposed method with low-cost magnetometers and GNSS receivers on a vehicle in a test drive. The calibration enabled a consistent heading determination with an accuracy of five degrees. This precise magnetometer-based attitude information allows an instantaneous GNSS integer ambiguity fixing.
Inflation and the Higgs Scalar
Energy Technology Data Exchange (ETDEWEB)
Green, Dan [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
2014-12-05
This note makes a self-contained exposition of the basic facts of big bang cosmology as they relate to inflation. The fundamental problems with that model are then explored. A simple scalar model of inflation is evaluated which provides the solution of those problems and makes predictions which will soon be definitively tested. The possibility that the recently discovered fundamental Higgs scalar field drives inflation is explored.
In-orbit magnetometer bias and scale factor calibration
Directory of Open Access Journals (Sweden)
Hajiyev Chingiz
2016-01-01
Full Text Available Magnetometers are widely used for LEO small satellites attitude determination and control system. In order to estimate satellite dynamics and control attitude accurately, scale factor and bias of magnetometer must be estimated. In this study a linear Kalman filter (LKF based algorithm for the estimation of magnetometer biases and scale factors is proposed. Proposed algorithms are simulated through attitude dynamics of a small satellite.
Solid-state magnetometer using electrically detected magnetic resonance
Energy Technology Data Exchange (ETDEWEB)
Jander, A., E-mail: jander@eecs.oregonstate.ed [Oregon State University, Corvallis, OR 97331 (United States); Dhagat, P. [Oregon State University, Corvallis, OR 97331 (United States)
2010-05-15
A silicon-based magnetometer utilizing spin-dependent recombination to electrically detect electron spin resonance is described. Electronic tracking of the resonant frequency provides an absolute, calibration-free measure of the magnetic field. The magnetometer can potentially be implemented entirely in conventional complementary metal-oxide-semiconductor (CMOS) integrated circuit technology. Based on published results for spin-dependent recombination in semiconductor diodes, an estimate of the achievable sensitivity and power consumption of an integrated magnetometer is derived.
Scalar - vector soliton fiber lasers
Wu, Zhichao; Li, Lei; Luo, Yiyang; Tang, Dingyuan; Shen, Deyuan; Tang, Ming; Fu, Songnian; Zhao, Luming
2016-01-01
Rapid progress in passively mode-locked fiber lasers is currently driven by the recent discovery of vector feature of mode-locking pulses, namely, the group velocity-locked vector solitons, the phase locked vector solitons, and the high-order vector solitons. Those vector solitons are fundamentally different from the previously known scalar solitons. Here, we report a fiber laser where the mode-locked pulse evolves as a vector soliton in the strong birefringent segment and is transformed into a regular scalar soliton after the polarizer within the laser cavity. The existence of solutions in a polarization-dependent cavity comprising a periodic combination of two distinct nonlinear waves is novel and likely to be applicable to various other nonlinear systems. For very large local birefringence, our laser approaches the working regime of vector soliton lasers, while it approaches scalar soliton fiber lasers under the conditions of very small birefringence.
Inoue, Takeshi; Ando, S.; Aoki, T.; Arikawa, H.; Ezure, S.; Harada, K.; Hayamizu, T.; Ishikawa, T.; Itoh, M.; Kato, K.; Kawamura, H.; Uchiyama, A.; Aoki, T.; Asahi, K.; Furukawa, T.; Hatakeyama, A.; Hatanaka, K.; Imai, K.; Murakami, T.; Nataraj, H. S.; Sato, T.; Shimizu, Y.; Wakasa, T.; Yoshimi, A.; Yoshida, H. P.; Sakemi, Y.
Toward an experimental search for an electron electric dipole moment by using laser cooled francium atoms, a development of a rubidium (Rb) atomic magnetometer based on a nonlinear magneto-optical rotation (NMOR) effect is presented. In order to obtain a narrow linewidth of the NMOR spectrum, a wall relaxation time of a paraffin coated glass cell, which confined the Rb atom, was experimentally confirmed. A residual field inside a magnetic shield was also evaluated.
Massive scalar counterpart of gravitational waves in scalarized neutron star binaries
Energy Technology Data Exchange (ETDEWEB)
Wang, Jing [Sun Yat-sen University, School of Physics and Astronomy, Guangzhou (China)
2017-09-15
In analogy with spontaneous magnetization of ferromagnets below the Curie temperature, a neutron star (NS), with a compactness above a certain critical value, may undergo spontaneous scalarization and exhibit an interior nontrivial scalar configuration. Consequently, the exterior spacetime is changed, and an external scalar field appears, which subsequently triggers a scalarization of its companion. The dynamical interplay produces a gravitational scalar counterpart of tensor gravitational waves. In this paper, we resort to scalar-tensor theory and demonstrate that the gravitational scalar counterpart from a double neutron star (DNS) and a neutron star-white dwarf (NS-WD) system become massive. We report that (1) a gravitational scalar background field, arising from convergence of external scalar fields, plays the role of gravitational scalar counterpart in scalarized DNS binary, and the appearance of a mass-dimensional constant in a Higgs-like gravitational scalar potential is responsible for a massive gravitational scalar counterpart with a mass of the order of the Planck scale; (2) a dipolar gravitational scalar radiated field, resulting from differing binding energies of NS and WD, plays the role of a gravitational scalar counterpart in scalarized orbital shrinking NS-WDs, which oscillates around a local and scalar-energy-density-dependent minimum of the gravitational scalar potential and obtains a mass of the order of about 10{sup -21} eV/c{sup 2}. (orig.)
Massive scalar counterpart of gravitational waves in scalarized neutron star binaries
Wang, Jing
2017-09-01
In analogy with spontaneous magnetization of ferromagnets below the Curie temperature, a neutron star (NS), with a compactness above a certain critical value, may undergo spontaneous scalarization and exhibit an interior nontrivial scalar configuration. Consequently, the exterior spacetime is changed, and an external scalar field appears, which subsequently triggers a scalarization of its companion. The dynamical interplay produces a gravitational scalar counterpart of tensor gravitational waves. In this paper, we resort to scalar-tensor theory and demonstrate that the gravitational scalar counterpart from a double neutron star (DNS) and a neutron star-white dwarf (NS-WD) system become massive. We report that (1) a gravitational scalar background field, arising from convergence of external scalar fields, plays the role of gravitational scalar counterpart in scalarized DNS binary, and the appearance of a mass-dimensional constant in a Higgs-like gravitational scalar potential is responsible for a massive gravitational scalar counterpart with a mass of the order of the Planck scale; (2) a dipolar gravitational scalar radiated field, resulting from differing binding energies of NS and WD, plays the role of a gravitational scalar counterpart in scalarized orbital shrinking NS-WDs, which oscillates around a local and scalar-energy-density-dependent minimum of the gravitational scalar potential and obtains a mass of the order of about 10^{-21} { {eV/c}}^2.
Scalar strong interaction hadron theory
Hoh, Fang Chao
2015-01-01
The scalar strong interaction hadron theory, SSI, is a first principles' and nonlocal theory at quantum mechanical level that provides an alternative to low energy QCD and Higgs related part of the standard model. The quark-quark interaction is scalar rather than color-vectorial. A set of equations of motion for mesons and another set for baryons have been constructed. This book provides an account of the present state of a theory supposedly still at its early stage of development. This work will facilitate researchers interested in entering into this field and serve as a basis for possible future development of this theory.
A Scanning Quantum Cryogenic Atom Microscope
Yang, Fan; Taylor, Stephen F; Turner, Richard W; Lev, Benjamin L
2016-01-01
Microscopic imaging of local magnetic fields provides a window into the organizing principles of complex and technologically relevant condensed matter materials. However, a wide variety of intriguing strongly correlated and topologically nontrivial materials exhibit poorly understood phenomena outside the detection capability of state-of-the-art high-sensitivity, high-resolution scanning probe magnetometers. We introduce a quantum-noise-limited scanning probe magnetometer that can operate from room-to-cryogenic temperatures with unprecedented DC-field sensitivity and micron-scale resolution. The Scanning Quantum Cryogenic Atom Microscope (SQCRAMscope) employs a magnetically levitated atomic Bose-Einstein condensate (BEC), thereby providing immunity to conductive and blackbody radiative heating. The SQCRAMscope has a noise floor of 300 pT and provides a 100x improvement in magnetic flux sensitivity over previous atomic scanning probe magnetometers. These capabilities are carefully benchmarked by imaging magnet...
Digital Fluxgate Magnetometer for Detection of Microvibration
Directory of Open Access Journals (Sweden)
Menghui Zhi
2017-01-01
Full Text Available In engineering practice, instruments, such as accelerometer and laser interferometer, are widely used in vibration measurement of structural parts. A method for using a triaxial fluxgate magnetometer as a microvibration sensor to measure low-frequency pendulum microvibration (not translational vibration is proposed in this paper, so as to detect vibration from low-frequency vibration sources, such as large rotating machine, large engineering structure, earthquake, and microtremor. This method provides vibration detection based on the environmental magnetic field signal to avoid increased measurement difficulty and error due to different relative positions of permanent magnet and magnetometer on the device under test (DUT when using the original magnetic measurement method. After fixedly connecting the fluxgate probe with the DUT during the test, the angular displacement due to vibration can be deduced by measuring the geomagnetic field’s magnetic induction intensity change on the orthogonal three components during the vibration. The test shows that the microvibration sensor has angular resolution of over 0.05° and maximum measuring frequency of 64 Hz. As an exploring test aimed to detect the microvibration of earth-orbiting satellite in the in-orbit process, the simulation experiment successfully provides the real-time microvibration information for attitude and orbit control subsystem.
Continuous reading SQUID magnetometer and its applications
JanÅ¯, Zdeněk; Soukup, František
2017-06-01
We show a continuous reading superconducting quantum interference detector magnetometer used to measure the magnetic moment of small samples of materials as a function of an applied magnetic field, temperature, and time. A sample is held stationary while the magnetic field and sample temperature may be varied continuously in an arbitrary way, determined by the user. The applied field range is ±25 mT and the temperature range is 4.2-150 K. The advantage of a stationary sample technique is that the sample is not exposed to variations in the magnetic field or temperature, which may set in when the sample is moving. An evaluation of the measurements is not bound by the dipolar magnetic moment of the sample. High linearity of the detection system, low harmonic distortion of the applied time-varying magnetic field, and precise sample temperature control make this device suitable for studies of phase transitions, hysteretic phenomena, and nonlinear phenomena in magnetic materials and superconductors. The magnetometer's sensitivity (noise floor), i.e., magnetic moment noise spectral density, is 10 pA m2 Hz-1/2 in the white noise region.
Magnetometer for Balloons and UAVs Project
National Aeronautics and Space Administration — This Phase I SBIR project will investigate a new, low-cost approach to atomic magnetometry that is suited for operation from UAVs and research balloons. Atomic...
Self-Compensating Excitation of Fluxgate Sensors for Space Magnetometers
DEFF Research Database (Denmark)
Cerman, Alec; Merayo, José M.G.; Brauer, Peter
2008-01-01
of the most crucial points, continuous by design of the self-compensating excitation unit and concludes with unit complex testing and application to the magnetometer. The application of the self-compensation of the excitation decreases temperature drift of the magnetometer offset caused by the temperature...... drift of the sensor (dominant source of the offset drift) by factor of 7....
Internet Access to ISEE-1 and 2 Magnetometer Data
1997-01-01
It is reported that the entire ISEE-1 and -2 magnetometer data are placed on-line, using an 8 Gbyte disk drive. The data are stored at 4-s and 60-s resolution. Also, an interactive world wide web page, which allows to plot, on request, any interval for which magnetometer data are available, is developed.
Digital fluxgate magnetometer for the "Astrid-2" satellite
DEFF Research Database (Denmark)
Pedersen, Erik Bøje; Primdahl, Fritz; Petersen, Jan Raagaard
1999-01-01
The design and performance of the Astrid-2 magnetometer are described. The magnetometer uses mathematical routines implemented by software for commercially available digital dignal processors to determine the magnetic field from the fluxgate sensor. The sensor is from the latest generation of amo...
SCALAR AND VECTOR IN COMPULATION
Directory of Open Access Journals (Sweden)
Valery F. Ochkov
2013-01-01
Full Text Available The article deals with two fundamental data types – scalar and vector (array, without the ability of working with them one cannot solve using computer school or university tasks in mathematics, physics, chemistry and other technical training courses. Some fundamentals of teaching computer science at school and university are covered as well.
Veltman, M.J.G.; Hooft, G. 't
1979-01-01
The completely general one-loop scalar one-, two-, three- and four-point functions are studied. Also an integral occurring in connection with soft bremsstrahlung is considered. Formulas in terms of Spence functions are given. An expansion for Spence functions with complex argument is presented.
Alonso, Rodrigo; Manohar, Aneesh V.
2016-01-01
The $S$-matrix of a quantum field theory is unchanged by field redefinitions, and so only depends on geometric quantities such as the curvature of field space. Whether the Higgs multiplet transforms linearly or non-linearly under electroweak symmetry is a subtle question since one can make a coordinate change to convert a field that transforms linearly into one that transforms non-linearly. Renormalizability of the Standard Model (SM) does not depend on the choice of scalar fields or whether the scalar fields transform linearly or non-linearly under the gauge group, but only on the geometric requirement that the scalar field manifold ${\\mathcal M}$ is flat. We explicitly compute the one-loop correction to scalar scattering in the SM written in non-linear Callan-Coleman-Wess-Zumino (CCWZ) form, where it has an infinite series of higher dimensional operators, and show that the $S$-matrix is finite. Standard Model Effective Field Theory (SMEFT) and Higgs Effective Field Theory (HEFT) have curved ${\\mathcal M}$, ...
Huang, Ching-Yuan
2003-07-01
The asymptotically flat space-time with scalar fields is studied. It shows that the concepts of Bondi mass, Bondi mass loss, etc., are also applicable to other fields, although they were originally defined by gravity. The generating formulae of Bondi mass loss and angular momentum loss by a dynamics Hamiltonian over a hyperb oloid are given by the linearised theory.
Tachyonic field interacting with scalar (phantom) field
Chattopadhyay, Surajit; Debnath, Ujjal
2009-01-01
In this letter, we have considered the universe is filled with the mixture of tachyonic field and scalar or phantom field. If the tachyonic field interacts with scalar or phantom field, the interaction term decays with time and the energy for scalar field is transferred to tachyonic field or the energy for phantom field is transferred to tachyonic field. The tachyonic field and scalar field potentials always decrease, but phantom field potential always increases.
Passive Scalar Evolution in Peripheral Region
Lebedev, V. V.; Turitsyn, K. S.
2003-01-01
We consider evolution of a passive scalar (concentration of pollutants or temperature) in a chaotic (turbulent) flow. A universal asymptotic behavior of the passive scalar decay (homogenization) related to peripheral regions (near walls) is established. The passive scalar moments and its pair correlation function in the peripheral region are analyzed. A special case investigated in our paper is the passive scalar decay along a pipe.
Minimally coupled scalar field cosmology in anisotropic ...
Indian Academy of Sciences (India)
We study a spatially homogeneous and anisotropic cosmological model in the Einstein gravitational theory with a minimally coupled scalar field. We consider a non-interacting combination of scalar field and perfect fluid as the source of matter components which are separately conserved. The dynamics of cosmic scalar ...
Automated system for the calibration of magnetometers
DEFF Research Database (Denmark)
Petrucha, Vojtech; Kaspar, Petr; Ripka, Pavel
2009-01-01
University. There are three axes of rotation in this design (compared to two axes in the previous version). The addition of the third axis allows us to calibrate more complex devices. An electronic compass based on a vector fluxgate magnetometer and micro electro mechanical systems (MEMS) accelerometer...... is one example. The new platform can also be used to evaluate the parameters of the compass in all possible variations in azimuth, pitch, and roll. The system is based on piezoelectric motors, which are placed on a platform made of aluminum, brass, plastic, and glass. Position sensing is accomplished...... through custom-made optical incremental sensors. The system is controlled by a microcontroller, which executes commands from a computer. The properties of the system as well as calibration and measurement results will be presented. ©2009 American Institute of Physics...
Search for Scalar Leptons and Scalar Quarks at LEP
Achard, P.; Aguilar-Benitez, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M.G.; Anderhub, H.; Andreev, Valery P.; Anselmo, F.; Arefev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Baldew, S.V.; Banerjee, S.; Barczyk, A.; Barillere, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B.L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J.J.; Blyth, S.C.; Bobbink, G.J.; Bohm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J.G.; Brochu, F.; Burger, J.D.; Burger, W.J.; Cai, X.D.; Capell, M.; Cara Romeo, G.; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chang, Y.H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G.M.; Chen, H.F.; Chen, H.S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de la Cruz, B.; Cucciarelli, S.; van Dalen, J.A.; de Asmundis, R.; Deglon, P.; Debreczeni, J.; Degre, A.; Dehmelt, K.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; DeNotaristefani, F.; De Salvo, A.; Diemoz, M.; Dierckxsens, M.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M.T.; Duchesneau, D.; Duda, M.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.; Engler, A.; Eppling, F.J.; Extermann, P.; Falagan, M.A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J.H.; Filthaut, F.; Fisher, P.H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Iouri; Ganguli, S.N.; Garcia-Abia, Pablo; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z.F.; Grenier, Gerald Jean; Grimm, O.; Gruenewald, M.W.; Guida, M.; van Gulik, R.; Gupta, V.K.; Gurtu, A.; Gutay, L.J.; Haas, D.; Hatzifotiadou, D.; Hebbeker, T.; Herve, Alain; Hirschfelder, J.; Hofer, H.; Hohlmann, M.; Holzner, G.; Hou, S.R.; Hu, Y.; Jin, B.N.; Jones, Lawrence W.; de Jong, P.; Josa-Mutuberria, I.; Kafer, D.; Kaur, M.; Kienzle-Focacci, M.N.; Kim, J.K.; Kirkby, Jasper; Kittel, W.; Klimentov, A.; Konig, A.C.; Kopal, M.; Koutsenko, V.; Kraber, M.; Kraemer, R.W.; Kruger, A.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Le Goff, J.M.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Likhoded, S.; Lin, C.H.; Lin, W.T.; Linde, F.L.; Lista, L.; Liu, Z.A.; Lohmann, W.; Longo, E.; Lu, Y.S.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W.G.; Malgeri, L.; Malinin, A.; Mana, C.; Mans, J.; Martin, J.P.; Marzano, F.; Mazumdar, K.; McNeil, R.R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W.J.; Mihul, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G.B.; Muanza, G.S.; Muijs, A.J.M.; Musicar, B.; Musy, M.; Nagy, S.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Novak, T.; Kluge, Hannelies; Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci, P.; Paramatti, R.; Passaleva, G.; Patricelli, S.; Paul, Thomas Cantzon; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Petersen, B.; Piccolo, D.; Pierella, F.; Pioppi, M.; Piroue, P.A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofev, D.; Quartieri, J.; Rahal-Callot, G.; Rahaman, Mohammad Azizur; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P.G.; Ranieri, R.; Raspereza, A.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Riemann, S.; Riles, Keith; Roe, B.P.; Romero, L.; Rosca, A.; Rosier-Lees, S.; Roth, Stefan; Rosenbleck, C.; Roux, B.; Rubio, J.A.; Ruggiero, G.; Rykaczewski, H.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Schafer, C.; Schegelsky, V.; Schopper, H.; Schotanus, D.J.; Sciacca, C.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.; Steuer, M.; Stickland, D.P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L.Z.; Sushkov, S.; Suter, H.; Swain, J.D.; Szillasi, Z.; Tang, X.W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, Charles; Ting, Samuel C.C.; Ting, S.M.; Tonwar, S.C.; Toth, J.; Tully, C.; Tung, K.L.; Ulbricht, J.; Valente, E.; Van de Walle, R.T.; Vasquez, R.; Veszpremi, V.; Vesztergombi, G.; Vetlitsky, I.; Vicinanza, D.; Viertel, G.; Villa, S.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobev, I.; Vorobyov, A.A.; Wadhwa, M.; Wang, Q.; Wang, X.L.; Wang, Z.M.; Weber, M.; Wienemann, P.; Wilkens, H.; Wynhoff, S.; Xia, L.; Xu, Z.Z.; Yamamoto, J.; Yang, B.Z.; Yang, C.G.; Yang, H.J.; Yang, M.; Yeh, S.C.; Zalite, A.; Zalite, Yu.; Zhang, Z.P.; Zhao, J.; Zhu, G.Y.; Zhu, R.Y.; Zhuang, H.L.; Zichichi, A.; Zimmermann, B.; Zoller, M.
2004-01-01
Scalar partners of quarks and leptons, predicted in supersymmetric models, are searched for in e^+e^- collisions at centre-of-mass energies between 192GeV and 209GeV at LEP. No evidence for any such particle is found in a data sample of 450 pb^-1. Upper limits on their production cross sections are set and lower limits on their masses are derived in the framework of the Minimal Supersymmetric Standard Model.
Scalar fluctuations in dilatonic brane-worlds
Bozza, Valerio; Veneziano, Gabriele
2001-01-01
We derive and solve the full set of scalar perturbation equations for a class of five-dimensional brane--world solutions, with a dilaton scalar field coupled to the bulk cosmological constant and to a 3-brane. The spectrum contains one localized massless scalar mode, to be interpreted as an effective dilaton on the brane, inducing long--range scalar interactions. Two massive scalar modes yield corrections to Newton's law at short distances, which persist even in the limit of vanishing dilaton (namely, in the standard Randall--Sundrum configuration).
CP violating scalar Dark Matter
Energy Technology Data Exchange (ETDEWEB)
Cordero-Cid, A.; Hernández-Sánchez, J. [Instituto de Física and Facultad de Ciencias de la Electrónica, Benemérita Universidad Autónoma de Puebla, Apdo. Postal 542, C.P. 72570 Puebla (Mexico); Keus, V. [Department of Physics and Helsinki Institute of Physics, University of Helsinki, Gustaf Hallstromin katu 2, Helsinki, FIN-00014 (Finland); School of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ (United Kingdom); King, S.F. [School of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ (United Kingdom); Moretti, S. [School of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ (United Kingdom); Particle Physics Department, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX (United Kingdom); Rojas, D. [Instituto de Física and Facultad de Ciencias de la Electrónica, Benemérita Universidad Autónoma de Puebla, Apdo. Postal 542, C.P. 72570 Puebla (Mexico); Sokołowska, D. [Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw (Poland)
2016-12-05
We study an extension of the Standard Model (SM) in which two copies of the SM scalar SU(2) doublet which do not acquire a Vacuum Expectation Value (VEV), and hence are inert, are added to the scalar sector. We allow for CP-violation in the inert sector, where the lightest inert state is protected from decaying to SM particles through the conservation of a Z{sub 2} symmetry. The lightest neutral particle from the inert sector, which has a mixed CP-charge due to CP-violation, is hence a Dark Matter (DM) candidate. We discuss the new regions of DM relic density opened up by CP-violation, and compare our results to the CP-conserving limit and the Inert Doublet Model (IDM). We constrain the parameter space of the CP-violating model using recent results from the Large Hadron Collider (LHC) and DM direct and indirect detection experiments.
High transition-temperature SQUID magnetometers and practical applications
Energy Technology Data Exchange (ETDEWEB)
Dantsker, Eugene [Univ. of California, Berkeley, CA (United States). Dept. of Physics
1997-05-01
The design, fabrication and performance of SQUID magnetometers based on thin films of the high-transition temperature superconductor YBa_{2}Cu_{3}O_{7-x} (YBCO) are described. Essential to the achieving high magnetic field resolution at low frequencies is the elimination of 1/f flux noise due to thermally activated hopping of flux vortices between pinning sites in the superconducting films. Through improvements in processing, 1/f noise in single layer YBCO thin films and YBCO-SrTiO_{3}-YBCO trilayers was systematically reduced to allow fabrication of sensitive SQUID magnetometers. Both single-layer directly coupled SQUID magnetometers and multilayer magnetometers were fabricated, based on the dc SQUID with bicrystal grain boundary Josephson junctions. Multilayer magnetometers had a lower magnetic field noise for a given physical size due to greater effective sensing areas. A magnetometer consisting of a SQUID inductively coupled to the multiturn input coil of a flux transformer in a flip-chip arrangement had a field noise of 27 fT Hz^{-1/2} at 1 Hz and 8.5 fT Hz^{-1/2} at 1 kHz. A multiloop multilayer SQUID magnetometer had a field noise of 37 fT Hz^{-1/2} at 1 Hz and 18 fT Hz^{-1/2} at 1 kHz. A three-axis SQUID magnetometer for geophysical applications was constructed and operated in the field in the presence of 60 Hz and radiofrequency noise. Clinical quality magnetocardiograms were measured using multilayer SQUID magnetometers in a magnetically shielded room.
Energy Technology Data Exchange (ETDEWEB)
Alonso, Rodrigo [Department of Physics, University of California at San Diego,La Jolla, CA 92093 (United States); Jenkins, Elizabeth E.; Manohar, Aneesh V. [Department of Physics, University of California at San Diego,La Jolla, CA 92093 (United States); CERN TH Division,CH-1211 Geneva 23 (Switzerland)
2016-08-17
The S-matrix of a quantum field theory is unchanged by field redefinitions, and so it only depends on geometric quantities such as the curvature of field space. Whether the Higgs multiplet transforms linearly or non-linearly under electroweak symmetry is a subtle question since one can make a coordinate change to convert a field that transforms linearly into one that transforms non-linearly. Renormalizability of the Standard Model (SM) does not depend on the choice of scalar fields or whether the scalar fields transform linearly or non-linearly under the gauge group, but only on the geometric requirement that the scalar field manifold M is flat. Standard Model Effective Field Theory (SMEFT) and Higgs Effective Field Theory (HEFT) have curved M, since they parametrize deviations from the flat SM case. We show that the HEFT Lagrangian can be written in SMEFT form if and only if M has a SU(2){sub L}×U(1){sub Y} invariant fixed point. Experimental observables in HEFT depend on local geometric invariants of M such as sectional curvatures, which are of order 1/Λ{sup 2}, where Λ is the EFT scale. We give explicit expressions for these quantities in terms of the structure constants for a general G→H symmetry breaking pattern. The one-loop radiative correction in HEFT is determined using a covariant expansion which preserves manifest invariance of M under coordinate redefinitions. The formula for the radiative correction is simple when written in terms of the curvature of M and the gauge curvature field strengths. We also extend the CCWZ formalism to non-compact groups, and generalize the HEFT curvature computation to the case of multiple singlet scalar fields.
Random scalar fields and hyperuniformity
Ma, Zheng; Torquato, Salvatore
2017-06-01
Disordered many-particle hyperuniform systems are exotic amorphous states of matter that lie between crystals and liquids. Hyperuniform systems have attracted recent attention because they are endowed with novel transport and optical properties. Recently, the hyperuniformity concept has been generalized to characterize two-phase media, scalar fields, and random vector fields. In this paper, we devise methods to explicitly construct hyperuniform scalar fields. Specifically, we analyze spatial patterns generated from Gaussian random fields, which have been used to model the microwave background radiation and heterogeneous materials, the Cahn-Hilliard equation for spinodal decomposition, and Swift-Hohenberg equations that have been used to model emergent pattern formation, including Rayleigh-Bénard convection. We show that the Gaussian random scalar fields can be constructed to be hyperuniform. We also numerically study the time evolution of spinodal decomposition patterns and demonstrate that they are hyperuniform in the scaling regime. Moreover, we find that labyrinth-like patterns generated by the Swift-Hohenberg equation are effectively hyperuniform. We show that thresholding (level-cutting) a hyperuniform Gaussian random field to produce a two-phase random medium tends to destroy the hyperuniformity of the progenitor scalar field. We then propose guidelines to achieve effectively hyperuniform two-phase media derived from thresholded non-Gaussian fields. Our investigation paves the way for new research directions to characterize the large-structure spatial patterns that arise in physics, chemistry, biology, and ecology. Moreover, our theoretical results are expected to guide experimentalists to synthesize new classes of hyperuniform materials with novel physical properties via coarsening processes and using state-of-the-art techniques, such as stereolithography and 3D printing.
Energy Technology Data Exchange (ETDEWEB)
Foda, O. [Department of Mathematics and Statistics, University of Melbourne, Parkville, Victoria 3010 (Australia)], E-mail: foda@ms.unimelb.edu.au; Wheeler, M. [Department of Mathematics and Statistics, University of Melbourne, Parkville, Victoria 3010 (Australia)], E-mail: mwheeler@ms.unimelb.edu.au; Zuparic, M. [Department of Mathematics and Statistics, University of Melbourne, Parkville, Victoria 3010 (Australia)], E-mail: mzup@ms.unimelb.edu.au
2009-10-21
Using a Jacobi-Trudi-type identity, we show that the scalar product of a general state and a Bethe eigenstate in a finite-length XXZ spin-1/2 chain is (a restriction of) a KP {tau} function. This leads to a correspondence between the eigenstates and points on Sato's Grassmannian. Each of these points is a function of the rapidities of the corresponding eigenstate, the inhomogeneity variables of the spin chain and the crossing parameter.
VOYAGER 2 SATURN MAGNETOMETER RESAMPLED DATA 48.0 SEC
National Aeronautics and Space Administration — This data set includes Voyager 2 Saturn encounter magnetometer data that have been resampled at a 48.0 second sample rate. The data set is composed of 6 columns: 1)...
VOYAGER 2 JUPITER MAGNETOMETER RESAMPLED DATA 9.60 SEC
National Aeronautics and Space Administration — This data set includes Voyager 2 Jupiter encounter magnetometer data that have been resampled at a 9.6 second sample rate. The data set is composed of 6 columns: 1)...
VOYAGER 1 JUPITER MAGNETOMETER RESAMPLED DATA 9.60 SEC
National Aeronautics and Space Administration — This data set includes Voyager 1 Jupiter encounter magnetometer data that have been resampled at a 9.6 second sample rate. The data set is composed of 6 columns: 1)...
VOYAGER 1 SATURN MAGNETOMETER RESAMPLED DATA 1.92 SEC
National Aeronautics and Space Administration — This data set includes Voyager 1 Saturn encounter magnetometer data that have been resampled at a 1.92 second sample rate. The data set is composed of 6 columns: 1)...
VOYAGER 2 JUPITER MAGNETOMETER RESAMPLED DATA 1.92 SEC
National Aeronautics and Space Administration — This data set includes Voyager 2 Jupiter encounter magnetometer data that have been resampled at a 1.92 second sample rate. The data set is composed of 6 columns: 1)...
VOYAGER 2 SATURN MAGNETOMETER RESAMPLED DATA 9.60 SEC
National Aeronautics and Space Administration — This data set includes Voyager 2 Saturn encounter magnetometer data that have been resampled at a 9.6 second sample rate. The data set is composed of 6 columns: 1)...
VOYAGER 2 JUPITER MAGNETOMETER RESAMPLED DATA 48.0 SEC
National Aeronautics and Space Administration — This data set includes Voyager 2 Jupiter encounter magnetometer data that have been resampled at a 48.0 second sample rate. The data set is composed of 6 columns: 1)...
VOYAGER 1 SATURN MAGNETOMETER RESAMPLED DATA 48.0 SEC
National Aeronautics and Space Administration — This data set includes Voyager 1 Saturn encounter magnetometer data that have been resampled at a 48.0 second sample rate. The data set is composed of 6 columns: 1)...
VOYAGER 2 SATURN MAGNETOMETER RESAMPLED DATA 1.92 SEC
National Aeronautics and Space Administration — This data set includes Voyager 2 Saturn encounter magnetometer data that have been resampled at a 1.92 second sample rate. The data set is composed of 6 columns: 1)...
VOYAGER 1 JUPITER MAGNETOMETER RESAMPLED DATA 48.0 SEC
National Aeronautics and Space Administration — This data set includes Voyager 1 Jupiter encounter magnetometer data that have been resampled at a 48.0 second sample rate. The data set is composed of 6 columns: 1)...
VOYAGER 1 JUPITER MAGNETOMETER RESAMPLED DATA 1.92 SEC
National Aeronautics and Space Administration — This data set includes Voyager 1 Jupiter encounter magnetometer data that have been resampled at a 1.92 second sample rate. The data set is composed of 6 columns: 1)...
VOYAGER 1 SATURN MAGNETOMETER RESAMPLED DATA 9.60 SEC
National Aeronautics and Space Administration — This data set includes Voyager 1 Saturn encounter magnetometer data that have been resampled at a 9.6 second sample rate. The data set is composed of 6 columns: 1)...
Directory of Open Access Journals (Sweden)
Timofeeva Maria
2012-03-01
Full Text Available A theoretical and experimental comparison of optimized search coils based magnetometers, operating either in the Flux mode or in the classical Lenz-Faraday mode, is presented. The improvements provided by the Flux mode in terms of bandwidth and measuring range of the sensor are detailed. Theory, SPICE model and measurements are in good agreement. The spatial resolution of the sensor is studied which is an important parameter for applications in non destructive evaluation. A general expression of the magnetic sensitivity of search coils sensors is derived. Solutions are proposed to design magnetometers with reduced weight and volume without degrading the magnetic sensitivity. An original differential search coil based magnetometer, made of coupled coils, operating in flux mode and connected to a differential transimpedance amplifier is proposed. It is shown that this structure is better in terms of volume occupancy than magnetometers using two separated coils without any degradation in magnetic sensitivity. Experimental results are in good agreement with calculations.
Self-Calibrating Vector Helium Magnetometer (SVHM) Project
National Aeronautics and Space Administration — This Phase I SBIR proposal describes proposed development of a conceptual design for a Self-Calibrating Vector Helium Magnetometer (SVHM) for design and fabrication...
Correcting GOES-R Magnetometer Data for Stray Fields
Carter, Delano; Freesland, Douglas; Tadikonda, Sivakumara K.; Kronenwetter, Jeffrey; Todirita, Monica; Dahya, Melissa; Chu, Donald
2016-05-01
Time-varying spacecraft magnetic fields, i.e. stray fields, are a problem for magnetometer systems. While constant fields can be removed by calibration, stray fields are difficult to distinguish from ambient field variations. Putting two magnetometers on a long boom and solving for both the ambient and stray fields can help, but this gradiometer solution is more sensitive to noise than a single magnetometer. As shown here for the R-series Geostationary Operational Environmental Satellites (GOES-R), unless the stray fields are larger than the noise, simply averaging the two magnetometer readings gives a more accurate solution. If averaging is used, it may be worthwhile to estimate and remove stray fields explicitly. Models and estimation algorithms to do so are provided for solar array, arcjet and reaction wheel fields.
GALILEO ORBITER JUPITER RAW MAGNETOMETER DATA V1.0
National Aeronautics and Space Administration — This data set contains raw magnetic field data acquired by the Galileo Orbiter magnetometer at Jupiter. The data set covers the time period from 1995-11-06T00:21:30...
Self-Calibrating Vector Helium Magnetometer (SVHM) Project
National Aeronautics and Space Administration — This Phase 2 SBIR proposal describes the design, fabrication and calibration of a brass-board Self-Calibrating Vector Helium Magnetometer (SVHM). The SVHM instrument...
Low-Fiend Vector Magnetometer (V-400-LF) Project
National Aeronautics and Space Administration — This 2010 NASA SBIR Phase 1 proposal for an innovative Low-Field Vector Magnetometer (V-400-LF) is a response to subtopic S1.06 Particles and Field Sensors and...
Real-Time Hand-Held Magnetometer Array
2016-04-01
Time Magnetometer Array Geometrics ix 1.3 LIST OF ACRONYMS ADC – Analog to Digital Converter AFE – Analog Front End AGC – Automatic Gain...automatically and in real time. Linear arrays of magnetometer sensors have been deployed in many scenarios in unexploded ordnance (UXO) detection. These have...past or over a target. This leads to various positioning and time changing errors, which limits the accuracy of the device. However, linear arrays
Detection Range of Airborne Magnetometers in Magnetic Anomaly Detection
Chengjing Li; Shucai Huang; Daozhi Wei; Yu Zhong; K. Y. Gong
2015-01-01
Airborne magnetometers are utilized for the small-range search, precise positioning, and identification of the ferromagnetic properties of underwater targets. As an important performance parameter of sensors, the detection range of airborne magnetometers is commonly set as a fixed value in references regardless of the influences of environment noise, target magnetic properties, and platform features in a classical model to detect airborne magnetic anomalies. As a consequence, devi...
Man-Portable Simultaneous Magnetometer and EM System (MSEMS)
2008-12-01
75 Hz and aliasing at 15 Hz. This is expected, and is removed with a notch filter ...distribution of weight (indeed, in the photo at YPG below, the gray bulge behind the magnetometer is a gallon jug of water used as ballast). The EM61 battery...we chop it out with a notch filter . These figures show that MSEMS’ interleaving magnetometer period counter was functioning as expected. 12
Calibration of the fluxgate CSC vector magnetometers
DEFF Research Database (Denmark)
Merayo, José M.G.; Risbo, Torben; Primdahl, Fritz
1995-01-01
found. The non-linearity is less than 4.0 ppm, taking into account that the coil facility where the magnetometer has been scanned has a very low noise (0.5 nT p-p) but not sufficient low to precise much more in this parameter. There is no non-linearity over the entire temperature range. The sensor...... offsets are less than 2.0 nT and 10.0 nT for the flight and flight spare electronics, respectively. They have been determinated by two procedures which give consistant results. Firstly, as output in the spherical harmonic method, and secondly, by rotation of the CSC sensor by 180° in two axes. It does...... not change with temperature. The sensitivities are different in each axis, due to the fact that any ADC has its own oltage reference and there is a slight difference between them. They change linearly with temperature. The temperature coefficient for each sensor is different since the radius of the feedback...
Unified Dark Matter Scalar Field Models
Directory of Open Access Journals (Sweden)
Daniele Bertacca
2010-01-01
of a single scalar field accounts for a unified description of the Dark Matter and Dark Energy sectors, dubbed Unified Dark Matter (UDM models. In this framework, we consider the general Lagrangian of -essence, which allows to find solutions around which the scalar field describes the desired mixture of Dark Matter and Dark Energy. We also discuss static and spherically symmetric solutions of Einstein's equations for a scalar field with noncanonical kinetic term, in connection with galactic halo rotation curves.
Galactic collapse of scalar field dark matter
Energy Technology Data Exchange (ETDEWEB)
Alcubierre, Miguel [Max-Planck-Institut fuer Gravitationsphysik, Am Muehlenberg 1, D-14476 Golm (Germany); Guzman, F Siddhartha [Max-Planck-Institut fuer Gravitationsphysik, Am Muehlenberg 1, D-14476 Golm (Germany); Matos, Tonatiuh [Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del IPN, AP 14-740, 07000 Mexico, DF (Mexico); Nunez, Dario [Centre for Gravitational Physics and Geometry, Penn State University, University Park, PA 16802 (United States); Urena-Lopez, L Arturo [Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del IPN, AP 14-740, 07000 Mexico, DF (Mexico); Wiederhold, Petra [Departamento de Control Automatico, Centro de Investigacion y de Estudios Avanzados del IPN, AP 14-740, 07000 Mexico, DF (Mexico)
2002-10-07
We present a scenario for core galaxy formation based on the hypothesis of scalar field dark matter. We interpret galaxy formation through the collapse of a scalar field fluctuation. We find that a cosh potential for the self-interaction of the scalar field provides a reasonable scenario for the formation of a galactic core plus a remnant halo, which is in agreement with cosmological observations and phenomenological studies in galaxies.
Matzka, J.; Johnsen, M. G.; Hoppe, U. P.; Serrano, A.
2016-12-01
By means of optical pumping, it is possible to use the naturally occurring sodium layer in the mesosphere to measure Earth's scalar magnetic field at 90 km above ground. This is an altitude not accessible by other means than rockets, which only will provide point measurements of very short time scales. We are planning to modify the sodium lidar at ALOMAR in Northern Norway to be able, for the first time, to measure and monitor the magnetic field in situ in the high latitude mesosphere over longer time scales. The planned modifications to the lidar instrument will allow alternating between the new magnetometer mode and its present mode for atmospheric temperatures and winds. The technique, which has been proposed earlier for measurements at low or mid-latitudes for studies of Earth's internal magnetic field, will in our project be applied to high latitudes in the auroral zone. This opens for a completely new domain of measurements of externally generated geomagnetic variations related to currents in the magnetosphere-ionosphere system. In particular, we aim to measure the magnetic field variations in close vicinity to Birkeland currents associated with particle precipitation events penetrating to altitudes below 90 km and small-scale, discrete auroral arcs. It is, furthermore, anticipated that it will be possible to detect horizontal current structures in the E-layer on much smaller length scales than it is presently possible from ground observations alone. During the project we plan take advantage of the rich space science infrastructure located in northern Norway, including ALOMAR, EISCAT and the Tromsø Geophysical Observatory magnetometer network. If possible, we also aim to make measurements in conjunction with overpasses of the SWARM satellites.
Schwarzschild black holes can wear scalar wigs.
Barranco, Juan; Bernal, Argelia; Degollado, Juan Carlos; Diez-Tejedor, Alberto; Megevand, Miguel; Alcubierre, Miguel; Núñez, Darío; Sarbach, Olivier
2012-08-24
We study the evolution of a massive scalar field surrounding a Schwarzschild black hole and find configurations that can survive for arbitrarily long times, provided the black hole or the scalar field mass is small enough. In particular, both ultralight scalar field dark matter around supermassive black holes and axionlike scalar fields around primordial black holes can survive for cosmological times. Moreover, these results are quite generic in the sense that fairly arbitrary initial data evolve, at late times, as a combination of those long-lived configurations.
Low energy constraints and scalar leptoquarks⋆
Directory of Open Access Journals (Sweden)
Fajfer Svjetlana
2014-01-01
Full Text Available The presence of a colored weak doublet scalar state with mass below 1 TeV can provide an explanation of the observed branching ratios in B → D(∗τντ decays. Constraints coming from Z → bb̄, muon g − 2, lepton flavor violating decays are derived. The colored scalar is accommodated within 45 representation of SU(5 group of unification. We show that presence of color scalar can improve mass relations in the up-type quark sector mass. Impact of the colored scalar embedding in 45-dimensional representation of SU(5 on low-energy phenomenology is also presented.
Scalar scattering via conformal higher spin exchange
Energy Technology Data Exchange (ETDEWEB)
Joung, Euihun [School of Physics and Astronomy,Seoul National University, Seoul 151-747 (Korea, Republic of); Gauge, Gravity & Strings, Center for Theoretical Physics of the Universe,Institute for Basic Sciences, Daejeon 34047 (Korea, Republic of); Nakach, Simon; Tseytlin, Arkady A. [Theoretical physics group, Blackett Laboratory,Imperial College London, SW7 2AZ (United Kingdom)
2016-02-18
Theories containing infinite number of higher spin fields require a particular definition of summation over spins consistent with their underlying symmetries. We consider a model of massless scalars interacting (via bilinear conserved currents) with conformal higher spin fields in flat space. We compute the tree-level four-scalar scattering amplitude using a natural prescription for summation over an infinite set of conformal higher spin exchanges and find that it vanishes. Independently, we show that the vanishing of the scalar scattering amplitude is, in fact, implied by the global conformal higher spin symmetry of this model. We also discuss one-loop corrections to the four-scalar scattering amplitude.
Charged composite scalar dark matter
Balkin, Reuven; Ruhdorfer, Maximilian; Salvioni, Ennio; Weiler, Andreas
2017-11-01
We consider a composite model where both the Higgs and a complex scalar χ, which is the dark matter (DM) candidate, arise as light pseudo Nambu-Goldstone bosons (pNGBs) from a strongly coupled sector with TeV scale confinement. The global symmetry structure is SO(7)/SO(6), and the DM is charged under an exact U(1)DM ⊂ SO(6) that ensures its stability. Depending on whether the χ shift symmetry is respected or broken by the coupling of the top quark to the strong sector, the DM can be much lighter than the Higgs or have a weak-scale mass. Here we focus primarily on the latter possibility. We introduce the lowest-lying composite resonances and impose calculability of the scalar potential via generalized Weinberg sum rules. Compared to previous analyses of pNGB DM, the computation of the relic density is improved by fully accounting for the effects of the fermionic top partners. This plays a crucial role in relaxing the tension with the current DM direct detection constraints. The spectrum of resonances contains exotic top partners charged under the U(1)DM, whose LHC phenomenology is analyzed. We identify a region of parameters with f = 1.4 TeV and 200 GeV ≲ m χ ≲ 400 GeV that satisfies all existing bounds. This DM candidate will be tested by XENON1T in the near future.
Axially symmetric static scalar solitons and black holes with scalar hair
Energy Technology Data Exchange (ETDEWEB)
Kleihaus, Burkhard, E-mail: kleihaus@theorie.physik.uni-oldenburg.de; Kunz, Jutta; Radu, Eugen; Subagyo, Bintoro
2013-10-01
We construct static, asymptotically flat black hole solutions with scalar hair. They evade the no-hair theorems by having a scalar potential which is not strictly positive. By including an azimuthal winding number in the scalar field ansatz, we find hairy black hole solutions which are static but axially symmetric only. These solutions possess a globally regular limit, describing scalar solitons. A branch of axially symmetric black holes is found to possess a positive specific heat.
An improved proton magnetometer for Earth's magnetic field observation
Xiao, Chengyu; Zhang, Shuang; Guo, Xin; Fu, Haoyang
2015-09-01
As a precision instrument to measure the earth magnetic field, proton magnetometer is widely used in different fields such as geological survey, buried objects detection and earth field variations. Due to poor signal to noise ratio (SNR) of the system, proton magnetometer suffers from low sensitivity which directly affects the performance. In order to increase the sensitivity, we present an improved proton magnetometer. First, the effect of matching resistance on Q value is discussed to enhance SNR, and high matching resistance has been chosen to improve the Q value of the resonant circuit. Second, noise induced by pre-amplifier is investigated in order to obtain low noise signal, and we adopt the JFET with noise figure less than 0.5dB as the pre-amplifier. Third, by using band-pass filter, low-noise output signal is obtained. Fourth, the method of period measurement based on CPLD is employed to measure frequency of the square wave shaped from the output sinusoidal signal. High precision temperature compensate crystal oscillator (TCXO) has been used to improve the frequency measurement accuracy. Last, experimental data is obtained through field measurements. By calculating the standard deviation, the sensitivity of the improved proton magnetometer is 0.15nT for Earth's magnetic field observation. Experimental results show that the new magnetometer is sensitive to earth field measurement.
An improved RF circuit for Overhauser magnetometer excitation
Zheng, Di; Zhang, Shuang; Guo, Xin; Fu, Haoyang
2015-08-01
Overhauser magnetometer is a high-precision device for magnetostatic field measurement, which can be used in a wide variety of purposes: UXO detection, pipeline mapping and other engineering and environmental applications. Traditional proton magnetometer adopts DC polarization, suffering from low polarization efficiency, high power consumption and low signal noise ratio (SNR). Compared with the traditional proton magnetometer, nitroxide free radicals are used for dynamic nuclear polarization (DNP) to enhance nuclear magnetic resonance (NMR). RF excitation is very important for electron resonance in nitrogen oxygen free radical solution, and it is primarily significant for the obtention of high SNR signal and high sensitive field observation. Therefore, RF excitation source plays a crucial role in the development of Overhauser magnetometer. In this paper, an improved design of a RF circuit is discussed. The new RF excitation circuit consists of two parts: Quartz crystal oscillator circuit and RF power amplifier circuit. Simulation and optimization designs for power amplifier circuit based on software ADS are presented. Finally we achieve a continuous and stable sine wave of 60MHz with 1-2.5 W output power, and the second harmonic suppression is close to -20dBc. The improved RF circuit has many merits such as small size, low-power consumption and high efficiency, and it can be applied to Overhauser magnetometer to obtain high sensitive field observation.
Scalar resonances as two-quark systems
Energy Technology Data Exchange (ETDEWEB)
Shabalin, E.P.
1985-07-01
On the basis of a theory with an effective U(3)xU(3)-symmetric chiral Lagrangian it is possible to determine the properties of two-quark scalar mesons and to show that the scalar resonances delta(980) and k(1240) can be treated as P-wave states of the q-barq system.
Minimally coupled scalar field cosmology in anisotropic ...
Indian Academy of Sciences (India)
2017-01-03
Jan 3, 2017 ... modern cosmology to explain the early inflation and the late-time acceleration. The recent discovery of cosmic acceleration [3–7] has stimulated the interest to study cosmological models based on scalar fields. The cosmological models based on scalar fields have been discussed by many researchers for ...
Scalar field dark matter in hybrid approach
Friedrich, Pavel; Prokopec, Tomislav
2017-10-01
We develop a hybrid formalism suitable for modeling scalar field dark matter, in which the phase-space distribution associated with the real scalar field is modeled by statistical equal-time two-point functions and gravity is treated by two stochastic gravitational fields in the longitudinal gauge (in this work we neglect vector and tensor gravitational perturbations). Inspired by the commonly used Newtonian Vlasov-Poisson system, we firstly identify a suitable combination of equal-time two-point functions that defines the phase-space distribution associated with the scalar field and then derive both a kinetic equation that contains relativistic scalar matter corrections as well as linear gravitational scalar field equations whose sources can be expressed in terms of a momentum integral over the phase-space distribution function. Our treatment generalizes the commonly used classical scalar field formalism, in that it allows for modeling of (dynamically generated) vorticity and perturbations in anisotropic stresses of the scalar field. It also allows for a systematic inclusion of relativistic and higher-order corrections that may be used to distinguish different dark matter scenarios. We also provide initial conditions for the statistical equal-time two-point functions of the matter scalar field in terms of gravitational potentials and the scale factor.
Psycholinguistic and Neurolinguistic Investigations of Scalar Implicature
Politzer-Ahles, Stephen
2013-01-01
The present study examines the representation and composition of meaning in scalar implicatures. Scalar implicature is the phenomenon whereby the use of a less informative term (e.g., "some") is inferred to mean the negation of a more informative term (e.g., to mean "not all"). The experiments reported here investigate how the…
scalar field dynamics on a brane
Indian Academy of Sciences (India)
power-law potential V ~φa is investigated. We describe solutions for which the scalar field energy density scales as a power-law of the scale factor. We also describe solutions existing in regions of the parameter space where these scaling solutions are unstable or do not exist. Keywords. Brane; scalar field; scaling solution.
Scalar Potential Model of light
Hodge, John
2008-04-01
Some observations of light are inconsistent with a wave--like model. Other observations of light are inconsistent with a particle--like model. A model of light is proposed wherein Newton's and Democritus's speculations are combined with the cosmological scalar potential model (SPM). The SPM was tested by confrontation with observations of galaxy HI rotation curves (RCs), asymmetric RCs, redshift, discrete redshift, galaxy central mass, and central velocity dispersion; and with observations of the Pioneer Anomaly. The resulting model of light will be tested by numerical simulation of a photon behaving in a wave-like manner such as diffusion, interference, reflection, spectrography, and the Afshar experiment. Although the SPM light model requires more work, early results are beginning to emerge that suggest possible tests because a few predictions are inconsistent with both the current particle and wave models of light and that suggest a re-interpretation of the equations of quantum mechanics.
Pair condensation in massless scalar electrodynamics
Hey, Anthony J. G.; Mandula, Jeffrey E.
1982-05-01
Motivated by the instabilities of the vacuum to bound-state pair production at large coupling in both abelian and non-abelian gauge theories, we examine the stability of the vacuum of a constrained version of massless scalar electrodynamics to the formation of a scalar pair condensate. The trial states are constructed by analogy with the BCS ground state of super-conductivity and are such that the vacuum expectation value of the scalar field vanishes. Analysis of the minimization equation for the energy density indicates that there are two phases as a function of the coupling constant. Under the constraint that the vacuum expectation value of the scalar field be zero, we find what, for small coupling, the perturbative vacuum minimizes the energy, while for large coupling a condensate of particle-antiparticle pairs is energetically favored. After discussing the relation of our results to the phase structure of unconstrained scalar electrodynamics, we speculate on possible implications for QCD.
Pair condensation in massless scalar electrodynamics
Energy Technology Data Exchange (ETDEWEB)
Hey, A.J.G. (Southampton Univ. (UK). Dept. of Physics); Mandula, J.E. (Washington Univ., St. Louis, MO (USA). Dept. of Physics)
1982-05-03
Motivated by the instabilities of the vacuum to bound-state pair production at large coupling in both abelian and non-abelian gauge theories, we examine the stability of the vacuum of a constrained version of massless scalar electrodynamics to the formation of a scalar pair condensate. The trial states are constructed by analogy with the BCS ground state of super-conductivity and are such that the vacuum expectation value of the scalar field vanishes. Analysis of the minimization equation for the energy density indicates that there are two phases as a function of the coupling constant. Under the constraint that the vacuum expectation value of the scalar field be zero, we find that, for small coupling, the perturbative vacuum minimizes the energy, while for large coupling a condensate of particle-antiparticle pairs is energetically favored. After discussing the relation of our results to the phase structure of unconstrained scalar electrodynamics, we speculate on possible implications for QCD.
Gan, Qi; Shang, Jintang; Ji, Yu; Wu, Lei
2017-11-01
We report a novel method adopting two RF fields to simultaneously excite 85Rb and 87Rb isotopes for an MZ type atomic magnetometer. The MZ magnetometer adopts a 6 mm3 microfabricated vapor cell with natural abundance rubidium and 0.74 amagat nitrogen as buffer gas inside. The excessively broadened magnetic resonance signals of the two rubidium isotopes overlap with each other and cause deterioration in accuracy and sensitivity performance. To solve this problem, a Double-RF Field Method (DRFM) is proposed, which adopts two RF fields with a central frequency ratio of 2:3. Compared with traditional Single-RF Field Method (SRFM), the DRFM reduces the detection error by over 50% and improves the sensitivity by more than 10%. The experiments are conducted at three temperatures and under various static magnetic fields. Theoretical models are also built to discuss the performance improvement of the magnetometer by the DRFM against the SRFM. This method provides a way to improve the performance of chip-scale MZ atomic magnetometers with low cost natural abundance rubidium.
Magnetometer with a miniature transducer and automatic scanning
Debnam, W. J. J.; Fales, C. L., Jr.; Breckenridge, R. A.; Pohm, A. V. (Inventor)
1978-01-01
The magnetometer is based on the time variation of the magnetic permeability in the magnetic material of its transducer; however, its operation is substantially different from the ordinary flux-gate magnetometer. The transducer uses 0.05 mm diameter plated magnetic wire and is made flat enabling it to make measurements of transverse magnetic fields as close as 0.08 mm from the surface, and it has very good spatial resolution because of its small active region of approximately 0.64 mm by 0.76 mm. The magnetometer uses an inexpensive clip-on millimeter for driving and processing the electrical signals and readout. It also utilizes an automatic scanning technique which is made possible by a specially designed transducer holding mechanism that replaces the ink pen on an X-Y recorder.
Design and Analyses of a MEMS Based Resonant Magnetometer
Directory of Open Access Journals (Sweden)
Dahai Ren
2009-09-01
Full Text Available A novel design of a MEMS torsional resonant magnetometer based on Lorentz force is presented and fabricated. The magnetometer consists of a silicon resonator, torsional beam, excitation coil, capacitance plates and glass substrate. Working in a resonant condition, the sensor’s vibration amplitude is converted into the sensing capacitance change, which reflects the outside magnetic flux-density. Based on the simulation, the key structure parameters are optimized and the air damping effect is estimated. The test results of the prototype are in accordance with the simulation results of the designed model. The resolution of the magnetometer can reach 30 nT. The test results indicate its sensitivity of more than 400 mV/μT when operating in a 10 Pa vacuum environment.
Assessing and ensuring GOES-R magnetometer accuracy
Carter, Delano; Todirita, Monica; Kronenwetter, Jeffrey; Dahya, Melissa; Chu, Donald
2016-05-01
The GOES-R magnetometer subsystem accuracy requirement is 1.7 nanoteslas (nT). During quiet times (100 nT), accuracy is defined as absolute mean plus 3 sigma error per axis. During storms (300 nT), accuracy is defined as absolute mean plus 2 sigma error per axis. Error comes both from outside the magnetometers, e.g. spacecraft fields and misalignments, as well as inside, e.g. zero offset and scale factor errors. Because zero offset and scale factor drift over time, it will be necessary to perform annual calibration maneuvers. To predict performance before launch, we have used Monte Carlo simulations and covariance analysis. With the proposed calibration regimen, both suggest that the magnetometer subsystem will meet its accuracy requirements.
Cavity enhanced atomic magnetometry.
Crepaz, Herbert; Ley, Li Yuan; Dumke, Rainer
2015-10-20
Atom sensing based on Faraday rotation is an indispensable method for precision measurements, universally suitable for both hot and cold atomic systems. Here we demonstrate an all-optical magnetometer where the optical cell for Faraday rotation spectroscopy is augmented with a low finesse cavity. Unlike in previous experiments, where specifically designed multipass cells had been employed, our scheme allows to use conventional, spherical vapour cells. Spherical shaped cells have the advantage that they can be effectively coated inside with a spin relaxation suppressing layer providing long spin coherence times without addition of a buffer gas. Cavity enhancement shows in an increase in optical polarization rotation and sensitivity compared to single-pass configurations.
Cavity enhanced atomic magnetometry
Crepaz, Herbert; Dumke, Rainer
2015-01-01
Atom sensing based on Faraday rotation is an indispensable method for precision measurements, universally suitable for both hot and cold atomic systems. Here we demonstrate an all-optical magnetometer where the optical cell for Faraday rotation spectroscopy is augmented with a low finesse cavity. Unlike in previous experiments, where specifically designed multipass cells had been employed, our scheme allows to use conventional, spherical vapour cells. Spherical shaped cells have the advantage that they can be effectively coated inside with a spin relaxation suppressing layer providing long spin coherence times without addition of a buffer gas. Cavity enhancement shows in an increase in optical polarization rotation and sensitivity compared to single-pass configurations.
Observations of interplanetary dust by the Juno magnetometer investigation
DEFF Research Database (Denmark)
Benn, Mathias; Jørgensen, John Leif; Denver, Troelz
2017-01-01
One of the Juno magnetometer investigation's star cameras was configured to search for unidentified objects during Juno's transit en route to Jupiter. This camera detects and registers luminous objects to magnitude 8. Objects persisting in more than five consecutive images and moving with an appa......One of the Juno magnetometer investigation's star cameras was configured to search for unidentified objects during Juno's transit en route to Jupiter. This camera detects and registers luminous objects to magnitude 8. Objects persisting in more than five consecutive images and moving...
Calibration of the Ørsted vector magnetometer
DEFF Research Database (Denmark)
Olsen, Nils; Tøffner-Clausen, Lars; Sabaka, T.J.
2003-01-01
The vector fluxgate magnetometer of the Orsted satellite is routinely calibrated by comparing its output with measurements of the absolute magnetic intensity from the Overhauser instrument, which is the second magnetometer of the satellite. We describe the method used for and the result obtained ...... coordinate system and the reference system of the star imager. This is done by comparing the magnetic and attitude measurements with a model of Earth's magnetic field. The Euler angles describing this rotation are determined in this way with an accuracy of better than 4 arcsec....
Associating ground magnetometer observations with current or voltage generators
DEFF Research Database (Denmark)
Hartinger, M. D.; Xu, Z.; Clauer, C. R.
2017-01-01
.”Statistical studies of ground magnetometer observations associated with dayside Transient High LatitudeCurrent Systems (THLCS) driven by similar mechanisms ﬁnd contradictory results using this paradigm:some studies associate THLCS with voltage generators, others with current generators. We argue that mostof...... this contradiction arises from two assumptions used to interpret ground magnetometer observations:(1) measurements made at ﬁxed position relative to the THLCS ﬁeld-aligned current and (2) negligibleauroral precipitation contributions to ionospheric conductivity. We use observations and simulations toillustrate how...
Internal Field of Homogeneously Magnetized Toroid Sensor for Proton Free Precession Magnetometer
DEFF Research Database (Denmark)
Primdahl, Fritz; Merayo, José M.G.; Brauer, Peter
2005-01-01
The shift of the NMR spectral line frequency in a proton free precession absolute scalar magnetometer using the omni-directional toroid container for a proton-rich liquid depends on the magnetic susceptibility of the liquid and on the direction of the external field relative to the axis...... of the toroid. The theoretical shift is estimated for water by computing the additional magnetic field from the magnetization of the liquid and comparing it to the theoretical field in a spherical container. Along the axis the estimated average shift is -0.08 nT and perpendicular to the axis the shift is +0.......08 nT relative to that of a spherical sensor. The field inhomogeneity introduced by the toroid shape amounts to 0.32 nT over the volume of the sensor and is not expected to significantly affect the signal decay time, when considering the typical water line width of about 2.5 InT....
Mixing among light scalar mesons and L=1 qq-bar scalar mesons
Energy Technology Data Exchange (ETDEWEB)
Teshima, T. [Department of Applied Physics, Chubu University, Kasugai (Japan)]. E-mail: teshima@isc.chubu.ac.jp; Kitamura, I.; Morisita, N. [Department of Applied Physics, Chubu University, Kasugai (Japan)
2002-06-01
Following the re-establishment of the {sigma}(500) and the {kappa}(900), the light scalar mesons a{sub 0}(980) and f{sub 0}(980) together with the {sigma}(500) and the {kappa}(900) are considered as the chiral scalar partner of pseudoscalar nonet in SU(3) chiral symmetry, and the high mass scalar mesons a{sub 0}(1450), K*{sub 0}(1430), f{sub 0}(1370) and f{sub 0}(1710) turned out to be considered as the L=1 qq-bar scalar mesons. We assume that the high mass of the L=1 qq-bar scalar mesons is caused by the mixing with the light scalar mesons. For the structure of the light scalar mesons, we adopted the qqq-barq-bar model in order to explain the 'scalar meson puzzle'. The inter-mixing between the light scalar nonet and the high mass L=1 qq-bar nonet and the intra-mixing among each nonet are analysed by including the glueball into the high mass scalar nonet. (author)
Kuvshinov, A. V.; Poedjono, B.; Matzka, J.; Olsen, N.; Pai, S.; Samrock, F.
2013-12-01
Most marine EM studies are based on sea-bottom measurements which are expensive and logistically demanding. We propose a low-cost and easy-to-deploy magnetic survey concept which exploits sea surface measurements. It is assumed that the exciting source can be described by a plane wave. The concept is based on responses that relate variations of the scalar magnetic field at the survey sites with variations of the horizontal magnetic field at a base site. It can be shown that these scalar responses are a mixture of standard tipper responses and elements of the horizontal magnetic tensor and thus can be used to probe the electrical conductivity of the subsoil. This opens an avenue for sea-surface induction studies which so far was believed very difficult to conduct if conventional approaches based on vector measurements are invoked. We perform 3-D realistic model studies where the target region was Oahu Island and its surroundings, and USGS operated Honolulu geomagnetic observatory was chosen as the base site. We compare the predicted responses with the responses estimated from the scalar data collected at a few locations around Oahu Island by the unmanned, autonomous, wave and solar powered 'Wave Glider' developed and operated by Liquid Robotics Oil and Gas/Schlumberger. The marine robots observation platform is equipped with a tow Overhauser magnetometer (validated by USGS). The studies show an encouraging agreement between predictions and experiment in both components of the scalar response at all locations and we consider this as a proof of the suggested concept.
Scalar QED, NLO and PHOTOS Monte Carlo
Nanava, G.; Was, Z.
2006-01-01
Recently, QED bremsstrahlung in $B$-meson decays into pair of scalars (\\pi's and/or K's) is of interest. If experimental acceptance must be taken into account, PHOTOS Monte Carlo is often used in experimental simulations. We will use scalar QED to benchmark PHOTOS, even though this theory is of limited use for complex objects. We present the analytical form of the kernel used in the older versions of PHOTOS, and the new, exact (scalar QED) one. Matrix element and phase-space Jacobians are sep...
Ionospheric travelling convection vortices observed by the Greenland magnetometer chain
DEFF Research Database (Denmark)
Kotsiaros, Stavros; Stolle, Claudia; Friis-Christensen, Eigil
2013-01-01
The Greenland magnetometer array continuously provides geomagnetic variometer data since the early eighties. With the polar cusp passing over it almost every day, the array is suitable to detect ionospheric traveling convection vortices (TCVs), which were rst detected by Friis-Christensen et al...
Small Fluxgate Magnetometers: Development and Future Trends in Spain
Directory of Open Access Journals (Sweden)
Lucas Pérez
2010-03-01
Full Text Available In this paper, we give an overview of the research on fluxgate magnetometers carried out in Spain. In particular we focus in the development of the planar-type instruments. We summarize the fabrication processes and signal processing developments as well as their use in complex systems and space.
Quantization of n coupled scalar field theory
Kim, Yong-Wan; Myung, Yun Soo; Park, Young-Jai
2013-10-01
We study a model of n coupled scalar fields in Minkowski spacetime in which all masses degenerate, which is considered as a toy model of polycritical gravity on anti-de Sitter spacetime. We quantize this model within the Becchi-Rouet-Stora-Tyutin scheme by introducing n Faddeev-Popov (FP) ghost fields. Extending a Becchi-Rouet-Stora-Tyutin quartet generated by two scalars and two FP ghosts to n scalars and n FP ghosts, there remains a physical subspace with positive norm for odd n, but there exists only the vacuum for even n. This clearly shows a nontriviality of odd higher-order derivative scalar field theories. This is helpful to understand the truncation mechanism, which is used to obtain a unitary conformal field theory dual to linearized polycritical gravity. It turns out that the truncation mechanism is nothing but a general quartet mechanism that appears when introducing the FP ghost action.
Entangled scalar and tensor fluctuations during inflation
Energy Technology Data Exchange (ETDEWEB)
Collins, Hael; Vardanyan, Tereza [Department of Physics, Carnegie Mellon University,5000 Forbes Avenue, Pittsburgh, Pennsylvania (United States)
2016-11-29
We show how the choice of an inflationary state that entangles scalar and tensor fluctuations affects the angular two-point correlation functions of the T, E, and B modes of the cosmic microwave background. The propagators for a state starting with some general quadratic entanglement are solved exactly, leading to predictions for the primordial scalar-scalar, tensor-tensor, and scalar-tensor power spectra. These power spectra are expressed in terms of general functions that describe the entangling structure of the initial state relative to the standard Bunch-Davies vacuum. We illustrate how such a state would modify the angular correlations in the CMB with a simple example where the initial state is a small perturbation away from the Bunch-Davies state. Because the state breaks some of the rotational symmetries, the angular power spectra no longer need be strictly diagonal.
Exotic Material as Interactions Between Scalar Fields
Directory of Open Access Journals (Sweden)
Robertson G. A.
2006-04-01
Full Text Available Many theoretical papers refer to the need to create exotic materials with average negative energies for the formation of space propulsion anomalies such as "wormholes" and "warp drives". However, little hope is given for the existence of such material to resolve its creation for such use. From the standpoint that non-minimally coupled scalar fields to gravity appear to be the current direction mathematically. It is proposed that exotic material is really scalar field interactions. Within this paper the Ginzburg-Landau (GL scalar fields associated with superconductor junctions isinvestigated as a source for negative vacuum energy fluctuations, which could be used to study the interactions among energyfluctuations, cosmological scalar (i.e., Higgs fields, and gravity.
Symmetry Breaking in a random passive scalar
Kilic, Zeliha; McLaughlin, Richard; Camassa, Roberto
2017-11-01
We consider the evolution of a decaying passive scalar in the presence of a gaussian white noise fluctuating shear flow. We focus on deterministic initial data and establish the short, intermediate, and long time symmetry properties of the evolving point wise probability measure for the random passive scalar. Analytical results are compared directly to Monte Carlo simulations. Time permitting we will compare the predictions to experimental observations.
Two component WIMP-FImP dark matter model with singlet fermion, scalar and pseudo scalar
Energy Technology Data Exchange (ETDEWEB)
Dutta Banik, Amit; Pandey, Madhurima; Majumdar, Debasish [Saha Institute of Nuclear Physics, HBNI, Astroparticle Physics and Cosmology Division, Kolkata (India); Biswas, Anirban [Harish Chandra Research Institute, Allahabad (India)
2017-10-15
We explore a two component dark matter model with a fermion and a scalar. In this scenario the Standard Model (SM) is extended by a fermion, a scalar and an additional pseudo scalar. The fermionic component is assumed to have a global U(1){sub DM} and interacts with the pseudo scalar via Yukawa interaction while a Z{sub 2} symmetry is imposed on the other component - the scalar. These ensure the stability of both dark matter components. Although the Lagrangian of the present model is CP conserving, the CP symmetry breaks spontaneously when the pseudo scalar acquires a vacuum expectation value (VEV). The scalar component of the dark matter in the present model also develops a VEV on spontaneous breaking of the Z{sub 2} symmetry. Thus the various interactions of the dark sector and the SM sector occur through the mixing of the SM like Higgs boson, the pseudo scalar Higgs like boson and the singlet scalar boson. We show that the observed gamma ray excess from the Galactic Centre as well as the 3.55 keV X-ray line from Perseus, Andromeda etc. can be simultaneously explained in the present two component dark matter model and the dark matter self interaction is found to be an order of magnitude smaller than the upper limit estimated from the observational results. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Yatake, Yo-ichi [Hitachi Ltd., Tokyo (Japan); Kume, Etsuo; Adachi, Masaaki; Ogasawara, Shinobu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan); Kawai, Wataru; Nemoto, Toshiyuki; Kawasaki, Nobuo; Ishizuki, Shigeru [Fujitsu Ltd., Tokyo (Japan)
2000-12-01
Several computer codes in the nuclear field have been vectorized, parallelized and transported on the FUJITSU VPP500 system, the AP3000 system, the SX-4 system and the Paragon system at Center for Promotion of Computational Science and Engineering in Japan Atomic Energy Research Institute. We dealt with 18 codes in fiscal 1999. These results are reported in 3 parts, i.e., the vectorization and the parallelization part on vector processors, the parallelization part on scalar processors and the porting part. In this report, we describe the parallelization on scalar processors. In this parallelization on scalar processors part, the parallelization of Nucleon Meson Transport Code (NMTC), Differential Algebraic VLASOV code (DA-VLASOV) and Monte Carlo N-Particle transport code (MCNP4B2) on the Paragon system are described. (author)
Design of a Low-Cost 2-Axes Fluxgate Magnetometer for Small Satellite Applications
Directory of Open Access Journals (Sweden)
Su-Jeoung Kim
2005-03-01
Full Text Available This paper addresses the design and analysis results of a 2-axes magnetometer for attitude determination of small satellite. A low-cost and efficient 2-axes fluxgate magnetometer was selected as the most suitable attitude sensor for LEO microsatellites which require a low-to-medium level pointing accuracy. An optimization trade-off study has been performed for the development of 2-axes fluxgate magnetometer. All the relevant parameters such as permeability, demagnetization factor, coil diameter, core thickness, and number of coil turns were considered for the sizing of a small satellite magnetometer. The magnetometer which is designed, manufactured, and tested in-house as described in this paper satisfies linearity requirement for determining attitude position of small satellites. On the basis of magnetometer which is designed in Space System Research Lab. (SSRL, commercial magnetometer will be developed.
Scanning Quantum Cryogenic Atom Microscope
Yang, Fan; Kollár, Alicia J.; Taylor, Stephen F.; Turner, Richard W.; Lev, Benjamin L.
2017-03-01
Microscopic imaging of local magnetic fields provides a window into the organizing principles of complex and technologically relevant condensed-matter materials. However, a wide variety of intriguing strongly correlated and topologically nontrivial materials exhibit poorly understood phenomena outside the detection capability of state-of-the-art high-sensitivity high-resolution scanning probe magnetometers. We introduce a quantum-noise-limited scanning probe magnetometer that can operate from room-to-cryogenic temperatures with unprecedented dc-field sensitivity and micron-scale resolution. The Scanning Quantum Cryogenic Atom Microscope (SQCRAMscope) employs a magnetically levitated atomic Bose-Einstein condensate (BEC), thereby providing immunity to conductive and blackbody radiative heating. The SQCRAMscope has a field sensitivity of 1.4 nT per resolution-limited point (approximately 2 μ m ) or 6 nT /√{Hz } per point at its duty cycle. Compared to point-by-point sensors, the long length of the BEC provides a naturally parallel measurement, allowing one to measure nearly 100 points with an effective field sensitivity of 600 pT /√{Hz } for each point during the same time as a point-by-point scanner measures these points sequentially. Moreover, it has a noise floor of 300 pT and provides nearly 2 orders of magnitude improvement in magnetic flux sensitivity (down to 10-6 Φ0/√{Hz } ) over previous atomic probe magnetometers capable of scanning near samples. These capabilities are carefully benchmarked by imaging magnetic fields arising from microfabricated wire patterns in a system where samples may be scanned, cryogenically cooled, and easily exchanged. We anticipate the SQCRAMscope will provide charge-transport images at temperatures from room temperature to 4 K in unconventional superconductors and topologically nontrivial materials.
Chameleon Induced Atomic Afterglow
Brax, Philippe
2010-01-01
The chameleon is a scalar field whose mass depends on the density of its environment. Chameleons are necessarily coupled to matter particles and will excite transitions between atomic energy levels in an analogous manner to photons. When created inside an optical cavity by passing a laser beam through a constant magnetic field, chameleons are trapped between the cavity walls and form a standing wave. This effect will lead to an afterglow phenomenon even when the laser beam and the magnetic field have been turned off, and could be used to probe the interactions of the chameleon field with matter.
Fast and slow thermal processes in harmonic scalar lattices
Kuzkin, V. A.; Krivtsov, A. M.
2017-12-01
An approach for analytical description of thermal processes in harmonic lattices is presented. We cover longitudinal and transverse vibrations of chains and out-of-plane vibrations of two-dimensional lattices with interactions of an arbitrary number of neighbors. The motion of each particle is governed by a single scalar equation and therefore the notion ‘scalar lattice’ is used. The evolution of initial temperature field in an infinite lattice is investigated. An exact equation describing the evolution is derived. Continualization of this equation with respect to spatial coordinates is carried out. The resulting continuum equation is solved analytically. The solution shows that the kinetic temperature is represented as the sum of two terms, one describing short time behavior, the other large time behavior. At short times, the temperature performs high-frequency oscillations caused by redistribution of energy among kinetic and potential forms (fast process). Characteristic time of this process is of the order of ten periods of atomic vibrations. At large times, changes of the temperature are caused by ballistic heat transfer (slow process). The temperature field is represented as a superposition of waves having the shape of initial temperature distribution and propagating with group velocities dependent on the wave vector. Expressions describing fast and slow processes are invariant with respect to substitution t by -t . However, examples considered in the paper demonstrate that these processes are irreversible. Numerical simulations show that presented theory describes the evolution of temperature field at short and large time scales with high accuracy.
Fundamental and composite scalars from extra dimensions
Energy Technology Data Exchange (ETDEWEB)
Aranda, Alfredo [Dual C-P Institute of High Energy Physics, Facultad de Ciencias, Universidad de Colima, Bernal Diaz del Castillo 340, Colima, Colima (Mexico)], E-mail: fefo@ucol.mx; Diaz-Cruz, J.L. [Dual C-P Institute of High Energy Physics, Facultad de Ciencias, Universidad de Colima, Bernal Diaz del Castillo 340, Colima, Colima (Mexico); Dual C-P Institute of High Energy Physics, Facultad de Ciencias Fisico-Matematicas, BUAP, Apdo. Postal 1364, C.P. 72000 Puebla, Pue (Mexico)], E-mail: lorenzo.diaz@fcfm.buap.mx; Hernandez-Sanchez, J. [Dual C-P Institute of High Energy Physics, Centro de Investigacion en Matematicas, Universidad Autonoma del Estado de Hidalgo, Carretera Pachuca-Tulancingo km. 4.5, C.P. 42184, Pachuca, Hidalgo (Mexico)], E-mail: jaimeh@uaeh.edu.mx; Noriega-Papaqui, R. [Dual C-P Institute of High Energy Physics, Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apdo. Postal 20-364, 01000 Mexico D.F. (Mexico)], E-mail: rnoriega@fisica.unam.mx
2007-12-13
We discuss a scenario consisting of an effective 4D theory containing fundamental and composite fields. The strong dynamics sector responsible for the compositeness is assumed to be of extra dimensional origin. In the 4D effective theory the SM fermion and gauge fields are taken as fundamental fields. The scalar sector of the theory resembles a bosonic topcolor in the sense there are two scalar Higgs fields, a composite scalar field and a fundamental gauge-Higgs unification scalar. A detailed analysis of the scalar spectrum is presented in order to explore the parameter space consistent with experiment. It is found that, under the model assumptions, the acceptable parameter space is quite constrained. As a part of our phenomenological study of the model, we evaluate the branching ratio of the lightest Higgs boson and find that our model predicts a large FCNC mode h{yields}tc, which can be as large as O(10{sup -3}). Similarly, a large BR for the top FCNC decay is obtained, namely BR(t{yields}c+H){approx_equal}10{sup -4}.
Space magnetometer based on an anisotropic magnetoresistive hybrid sensor
Brown, P.; Whiteside, B. J.; Beek, T. J.; Fox, P.; Horbury, T. S.; Oddy, T. M.; Archer, M. O.; Eastwood, J. P.; Sanz-Hernández, D.; Sample, J. G.; Cupido, E.; O'Brien, H.; Carr, C. M.
2014-12-01
We report on the design and development of a low resource, dual sensor vector magnetometer for space science applications on very small spacecraft. It is based on a hybrid device combining an orthogonal triad of commercial anisotropic magnetoresistive (AMR) sensors with a totem pole H-Bridge drive on a ceramic substrate. The drive enables AMR operation in the more sensitive flipped mode and this is achieved without the need for current spike transmission down a sensor harness. The magnetometer has sensitivity of better than 3 nT in a 0-10 Hz band and a total mass of 104 g. Three instruments have been launched as part of the TRIO-CINEMA space weather mission, inter-calibration against the International Geomagnetic Reference Field model makes it possible to extract physical signals such as field-aligned current deflections of 20-60 nT within an approximately 45 000 nT ambient field.
Combined alternating gradient force magnetometer and susceptometer system
Energy Technology Data Exchange (ETDEWEB)
Pérez, M.; Mendizábal Vázquez, I. de; Aroca, C. [Dpto. Física Aplicada, E.T.S.I. Telecomunicación, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, Madrid 28040 (Spain); Ranchal, R. [Dpto. Física de Materiales, Facultad Ciencias Físicas, Universidad Complutense de Madrid, Ciudad Universitaria s/n, Madrid 28040 (Spain); Cobos, P. [ISOM, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, Madrid 28040 (Spain)
2015-01-15
We report the design, fabrication, and characterization of a new system that combines the performances of two different types of magnetic characterization systems, Alternating Gradient Force Magnetometers (AGFM) and susceptometers. The flexibility of our system is demonstrated by its capability to be used as any of them, AGFM or susceptometer, without any modification in the experimental set-up because of the electronics we have developed. Our system has a limit of sensitivity lower than 5 × 10{sup −7} emu. Moreover, its main advantage is demonstrated by the possibility of measuring small quantities of materials under DC or AC magnetic fields that cannot properly be measured with a commercial vibrating sample magnetometers or AGFM.
Hansteen's magnetometer and the origin of the magnetic crusade.
Enebakk, Vidar
2014-12-01
In the early nineteenth century, Norwegian mathematician and astronomer Christopher Hansteen (1784-1873) contributed significantly to international collaboration in the study of terrestrial magnetism. In particular, Hansteen was influential in the origin and orientation of the magnetic lobby in Britain, a campaign which resulted in a global network of fixed geomagnetic observatories. In retrospect, however, his contribution was diminished, because his four-pole theory in Untersuchungen der Magnetismus der Erde (1819) was ultimately refuted by Carl Friedrich Gauss in Allgemeine Theorie des Erdmagnetismus (1839). Yet Hansteen's main contribution was practical rather than theoretical. His major impact was related to the circulation of his instruments and techniques. From the mid-1820s, 'Hansteen's magnetometer' was distributed all over the British Isles and throughout the international scientific community devoted to studying terrestrial magnetism. Thus in the decades before the magnetic crusade, Hansteen had established an international system of observation, standardization and representation based on measurements with his small and portable magnetometers.
Space magnetometer based on an anisotropic magnetoresistive hybrid sensor.
Brown, P; Whiteside, B J; Beek, T J; Fox, P; Horbury, T S; Oddy, T M; Archer, M O; Eastwood, J P; Sanz-Hernández, D; Sample, J G; Cupido, E; O'Brien, H; Carr, C M
2014-12-01
We report on the design and development of a low resource, dual sensor vector magnetometer for space science applications on very small spacecraft. It is based on a hybrid device combining an orthogonal triad of commercial anisotropic magnetoresistive (AMR) sensors with a totem pole H-Bridge drive on a ceramic substrate. The drive enables AMR operation in the more sensitive flipped mode and this is achieved without the need for current spike transmission down a sensor harness. The magnetometer has sensitivity of better than 3 nT in a 0-10 Hz band and a total mass of 104 g. Three instruments have been launched as part of the TRIO-CINEMA space weather mission, inter-calibration against the International Geomagnetic Reference Field model makes it possible to extract physical signals such as field-aligned current deflections of 20-60 nT within an approximately 45,000 nT ambient field.
Coherent Atom Optics with fast metastable rare gas atoms
Grucker, J.; Baudon, J.; Karam, J.-C.; Perales, F.; Bocvarski, V.; Vassilev, G.; Ducloy, M.
2006-12-01
Coherent atom optics experiments making use of an ultra-narrow beam of fast metastable atoms generated by metastability exchange are reported. The transverse coherence of the beam (coherence radius of 1.7 μm for He*, 1.2 μm for Ne*, 0.87 μm for Ar*) is demonstrated via the atomic diffraction by a non-magnetic 2μm-period reflection grating. The combination of the non-scalar van der Waals (vdW) interaction with the Zeeman interaction generated by a static magnetic field gives rise to "vdW-Zeeman" transitions among Zeeman sub-levels. Exo-energetic transitions of this type are observed with Ne*(3P2) atoms traversing a copper micro-slit grating. They can be used as a tunable beam splitter in an inelastic Fresnel bi-prism atom interferometer.
Fiber Optic Magnetometers Using Planar And Cylindrical Magnetostrictive Transducers
Bucholtz, F.; Yurek, A. M.; Koo, K. P.; Dandridge, A.
1987-04-01
Fiber optic magnetometers which require high sensitivity at low frequencies (dc-10 Hz) rely on the nonlinear magnetostriction of materials such as amorphous metallic glass alloys. Typically, fiber is bonded to a magnetostrictive sample to convert strain in the sample to phase shift in a fiber interferometer. We present the results of measurements of the frequency dependence and dc and ac magnetic field sensitivity of both planar and cylindrical transducing elements, and discuss the practical advantages and disadvan-tages of each configuration.
The Upgraded CARISMA Magnetometer Array in the THEMIS Era
Mann, I. R.; Milling, D. K.; Rae, I. J.; Ozeke, L. G.; Kale, A.; Kale, Z. C.; Murphy, K. R.; Parent, A.; Usanova, M.; Pahud, D. M.; Lee, E.-A.; Amalraj, V.; Wallis, D. D.; Angelopoulos, V.; Glassmeier, K.-H.; Russell, C. T.; Auster, H.-U.; Singer, H. J.
2008-12-01
This review describes the infrastructure and capabilities of the expanded and upgraded Canadian Array for Realtime InvestigationS of Magnetic Activity (CARISMA) magnetometer array in the era of the THEMIS mission. Formerly operated as the Canadian Auroral Network for the OPEN Program Unified Study (CANOPUS) magnetometer array until 2003, CARISMA capabilities have been extended with the deployment of additional fluxgate magnetometer stations (to a total of 28), the upgrading of the fluxgate magnetometer cadence to a standard data product of 1 sample/s (raw sampled 8 samples/s data stream available on request), and the deployment of a new network of 8 pairs of induction coils (100 samples per second). CARISMA data, GPS-timed and backed up at remote field stations, is collected using Very Small Aperture Terminal (VSAT) satellite internet in real-time providing a real-time monitor for magnetic activity on a continent-wide scale. Operating under the magnetic footprint of the THEMIS probes, data from 5 CARISMA stations at 29-30 samples/s also forms part of the formal THEMIS ground-based observatory (GBO) data-stream. In addition to technical details, in this review we also outline some of the scientific capabilities of the CARISMA array for addressing all three of the scientific objectives of the THEMIS mission, namely: 1. Onset and evolution of the macroscale substorm instability, 2. Production of storm-time MeV electrons, and 3. Control of the solar wind-magnetosphere coupling by the bow shock, magnetosheath, and magnetopause. We further discuss some of the compelling questions related to these three THEMIS mission science objectives which can be addressed with CARISMA.
A broadband two axis flux-gate magnetometer
Directory of Open Access Journals (Sweden)
P. Palangio
1998-06-01
Full Text Available A broadband two axis flux-gate magnetometer was developed to obtain high sensitivity in magnetotelluric measurements. In magnetotelluric sounding, natural low frequency electromagnetic fields are used to estimate the conductivity of the Earth's interior. Because variations in the natural magnetic field have small amplitude(10-100 pT in the frequency range 1 Hz to 100 Hz, highly sensitive magnetic sensors are required. In magnetotelluric measurements two long and heavy solenoids, which must be installed, in the field station, perpendicular to each other (north-south and east-west and levelled in the horizontal plane are used. The coil is a critical component in magnetotelluric measurements because very slight motions create noise voltages, particularly troublesome in wooded areas; generally the installation takes place in a shallow trench. Moreover the coil records the derivative of the variations rather than the magnetic field variations, consequently the transfer function (amplitude and phase of this sensor is not constant throughout the frequency range 0.001-100 Hz. The instrument, developed at L'Aquila Geomagnetic Observatory, has a flat response in both amplitude and phase in the frequency band DC-100 Hz, in addition it has low weight, low power, small volume and it is easier to install in the field than induction magnetometers. The sensivity of this magnetometer is 10 pT rms.
Detection Range of Airborne Magnetometers in Magnetic Anomaly Detection
Directory of Open Access Journals (Sweden)
Chengjing Li
2015-11-01
Full Text Available Airborne magnetometers are utilized for the small-range search, precise positioning, and identification of the ferromagnetic properties of underwater targets. As an important performance parameter of sensors, the detection range of airborne magnetometers is commonly set as a fixed value in references regardless of the influences of environment noise, target magnetic properties, and platform features in a classical model to detect airborne magnetic anomalies. As a consequence, deviation in detection ability analysis is observed. In this study, a novel detection range model is proposed on the basis of classic detection range models of airborne magnetometers. In this model, probability distribution is applied, and the magnetic properties of targets and the environment noise properties of a moving submarine are considered. The detection range model is also constructed by considering the distribution of the moving submarine during detection. A cell-averaging greatest-of-constant false alarm rate test method is also used to calculate the detection range of the model at a desired false alarm rate. The detection range model is then used to establish typical submarine search probabilistic models. Results show that the model can be used to evaluate not only the effects of ambient magnetic noise but also the moving and geomagnetic features of the target and airborne detection platform. The model can also be utilized to display the actual operating range of sensor systems.
Swarm Optimization-Based Magnetometer Calibration for Personal Handheld Devices
Directory of Open Access Journals (Sweden)
Naser El-Sheimy
2012-09-01
Full Text Available Inertial Navigation Systems (INS consist of accelerometers, gyroscopes and a processor that generates position and orientation solutions by integrating the specific forces and rotation rates. In addition to the accelerometers and gyroscopes, magnetometers can be used to derive the user heading based on Earth’s magnetic field. Unfortunately, the measurements of the magnetic field obtained with low cost sensors are usually corrupted by several errors, including manufacturing defects and external electro-magnetic fields. Consequently, proper calibration of the magnetometer is required to achieve high accuracy heading measurements. In this paper, a Particle Swarm Optimization (PSO-based calibration algorithm is presented to estimate the values of the bias and scale factor of low cost magnetometers. The main advantage of this technique is the use of the artificial intelligence which does not need any error modeling or awareness of the nonlinearity. Furthermore, the proposed algorithm can help in the development of Pedestrian Navigation Devices (PNDs when combined with inertial sensors and GPS/Wi-Fi for indoor navigation and Location Based Services (LBS applications.
Particle swarm optimization algorithm based low cost magnetometer calibration
Ali, A. S.; Siddharth, S., Syed, Z., El-Sheimy, N.
2011-12-01
Inertial Navigation Systems (INS) consist of accelerometers, gyroscopes and a microprocessor provide inertial digital data from which position and orientation is obtained by integrating the specific forces and rotation rates. In addition to the accelerometers and gyroscopes, magnetometers can be used to derive the absolute user heading based on Earth's magnetic field. Unfortunately, the measurements of the magnetic field obtained with low cost sensors are corrupted by several errors including manufacturing defects and external electro-magnetic fields. Consequently, proper calibration of the magnetometer is required to achieve high accuracy heading measurements. In this paper, a Particle Swarm Optimization (PSO) based calibration algorithm is presented to estimate the values of the bias and scale factor of low cost magnetometer. The main advantage of this technique is the use of the artificial intelligence which does not need any error modeling or awareness of the nonlinearity. The estimated bias and scale factor errors from the proposed algorithm improve the heading accuracy and the results are also statistically significant. Also, it can help in the development of the Pedestrian Navigation Devices (PNDs) when combined with the INS and GPS/Wi-Fi especially in the indoor environments
Noise characterization for the FID signal from proton precession magnetometer
Liu, H.; Dong, H.; Liu, Z.; Ge, J.; Bai, B.; Zhang, C.
2017-07-01
Proton precession magnetometer is a high-precision device for weak magnetostatic field measurement. The measurement accuracy depends on the frequency measurement of free induction decay (FID) signal, while the signal to noise ratio (SNR) is an important factor affecting the results. Many signal processing methods have been proposed to improve the SNR of FID signal. However, the theoretical analysis of different types of noises for FID signal has not be conducted yet. In addition, the relationship between the frequency measurement accuracy and SNR has not been explicitly established and quantified. This paper first proposes a background noise model based on the extracted features from the FID signal. With this model, background noises, such as white noise, narrow-band noise, and phase noise etc., can be calculated and estimated. Secondly, the relationship between the frequency measurement accuracy and SNR is identified. We also built a prototype proton magnetometer for field tests and validation purpose. Experiments were conducted to investigate this relation through simulation. Different values for frequency accuracy were obtained with different SNRs from the acquired FID signals from field tests. The consistence between the measurement and computational results is observed. When SNR is larger than 30 dB, the absolute frequency accuracy becomes constant which is about 0.04 Hz. With the stability taken into account, the accuracy can be better even when the SNR is higher than 30 dB. This study provides a reference to optimize the design of proton precession magnetometer and the frequency calculation for FID signal.
A spinner magnetometer for large Apollo lunar samples
Uehara, M.; Gattacceca, J.; Quesnel, Y.; Lepaulard, C.; Lima, E. A.; Manfredi, M.; Rochette, P.
2017-10-01
We developed a spinner magnetometer to measure the natural remanent magnetization of large Apollo lunar rocks in the storage vault of the Lunar Sample Laboratory Facility (LSLF) of NASA. The magnetometer mainly consists of a commercially available three-axial fluxgate sensor and a hand-rotating sample table with an optical encoder recording the rotation angles. The distance between the sample and the sensor is adjustable according to the sample size and magnetization intensity. The sensor and the sample are placed in a two-layer mu-metal shield to measure the sample natural remanent magnetization. The magnetic signals are acquired together with the rotation angle to obtain stacking of the measured signals over multiple revolutions. The developed magnetometer has a sensitivity of 5 × 10-7 Am2 at the standard sensor-to-sample distance of 15 cm. This sensitivity is sufficient to measure the natural remanent magnetization of almost all the lunar basalt and breccia samples with mass above 10 g in the LSLF vault.
Renormalisation group improvement of scalar field inflation
Contillo, Adriano; Rahmede, Christoph
2011-01-01
We study quantum corrections to Friedmann-Robertson-Walker cosmology with a scalar field under the assumption that the dynamics are subject to renormalisation group improvement. We use the Bianchi identity to relate the renormalisation group scale to the scale factor and obtain the improved cosmological evolution equations. We study the solutions of these equations in the renormalisation group fixed point regime, obtaining the time-dependence of the scalar field strength and the Hubble parameter in specific models with monomial and trinomial quartic scalar field potentials. We find that power-law inflation can be achieved in the renormalisation group fixed point regime with the trinomial potential, but not with the monomial one. We study the transition to the quasi-classical regime, where the quantum corrections to the couplings become small, and find classical dynamics as an attractor solution for late times. We show that the solution found in the renormalisation group fixed point regime is also a cosmologic...
Arbitrary scalar field and quintessence cosmological models
Harko, Tiberiu; Mak, M K
2014-01-01
The mechanism of the initial inflationary scenario of the universe and of its late-time acceleration can be described by assuming the existence of some gravitationally coupled scalar fields $\\phi $, with the inflaton field generating inflation and the quintessence field being responsible for the late accelerated expansion. Various inflationary and late-time accelerated scenarios are distinguished by the choice of an effective self-interaction potential $V(\\phi)$, which simulates a temporarily non-vanishing cosmological term. In this work, we present a new formalism for the analysis of scalar fields in flat isotropic and homogeneous cosmological models. The basic evolution equation of the models can be reduced to a first order non-linear differential equation. Approximate solutions of this equation can be constructed in the limiting cases of the scalar field kinetic energy and potential energy dominance, respectively, as well as in the intermediate regime. Moreover, we present several new accelerating and dece...
Dimensionality influence on passive scalar transport
Energy Technology Data Exchange (ETDEWEB)
Iovieno, M; Ducasse, L; Tordella, D, E-mail: michele.iovieno@polito.it [Dipartimento di Ingegneria Aeronautica e Spaziale, Politecnico di Torino (Italy)
2011-12-22
We numerically investigate the advection of a passive scalar through an interface placed inside a decaying shearless turbulent mixing layer. We consider the system in both two and three dimensions. The dimensionality produces a different time scaling of the diffusion, which is faster in the two-dimensional case. Two intermittent fronts are generated at the margins of the mixing layer. During the decay these fronts present a sort of propagation in both the direction of the scalar flow and the opposite direction. In two dimensions, the propagation of the fronts exhibits a significant asymmetry with respect to the initial position of the interface and is deeper for the front merged in the high energy side of the mixing. In three dimensions, the two fronts remain nearly symmetrically placed. Results concerning the scalar spectra exponents are also presented.
Scalar operators in solid-state NMR
Energy Technology Data Exchange (ETDEWEB)
Sun, Boqin [Univ. of California, Berkeley, CA (United States)
1991-11-01
Selectivity and resolution of solid-state NMR spectra are determined by dispersion of local magnetic fields originating from relaxation effects and orientation-dependent resonant frequencies of spin nuclei. Theoretically, the orientation-dependent resonant frequencies can be represented by a set of irreducible tensors. Among these tensors, only zero rank tensors (scalar operators) are capable of providing high resolution NMR spectra. This thesis presents a series of new developments in high resolution solid-state NMR concerning the reconstruction of various scalar operators motion in solid C_{60} is analyzed.
Extended solutions for the biadjoint scalar field
De Smet, Pieter-Jan; White, Chris D.
2017-12-01
Biadjoint scalar field theories are increasingly important in the study of scattering amplitudes in various string and field theories. Recently, some first exact nonperturbative solutions of biadjoint scalar theory were presented, with a pure power-like form corresponding to isolated monopole-like objects located at the origin of space. In this paper, we find a novel family of extended solutions, involving non-trivial form factors that partially screen the divergent field at the origin. All previous solutions emerge as special cases.
CSW rules for a massive scalar
DEFF Research Database (Denmark)
Boels, Rutger Herman; Schwinn, Christian
2008-01-01
We derive the analog of the Cachazo-Svrcek-Witten (CSW) diagrammatic Feynman rules for four-dimensional Yang-Mills gauge theory coupled to a massive colored scalar. The mass term is shown to give rise to a new tower of vertices in addition to the CSW vertices for massless scalars in non......-supersymmetric theories. The rules are derived directly from an action, once through a canonical transformation within light-cone Yang-Mills and once by the construction of a twistor action. The rules are tested against known results in several examples and are used to simplify the proof of on-shell recursion relations...
Scalar absorption by charged rotating black holes
Leite, Luiz C. S.; Benone, Carolina L.; Crispino, Luís C. B.
2017-08-01
We compute numerically the absorption cross section of planar massless scalar waves impinging upon a Kerr-Newman black hole with different incidence angles. We investigate the influence of the black hole electric charge and angular momentum in the absorption spectrum, comparing our numerical computations with analytical results for the limits of high and low frequency.
Oscillating scalar fields in extended quintessence
Li, Dan; Pi, Shi; Scherrer, Robert J.
2018-01-01
We study a rapidly oscillating scalar field with potential V (ϕ )=k |ϕ |n nonminimally coupled to the Ricci scalar R via a term of the form (1 -8 π G0ξ ϕ2)R in the action. In the weak coupling limit, we calculate the effect of the nonminimal coupling on the time-averaged equation of state parameter γ =(p +ρ )/ρ . The change in ⟨γ ⟩ is always negative for n ≥2 and always positive for n values of n . Constraints on the time variation of G force this change to be infinitesimally small at the present time whenever the scalar field dominates the expansion, but constraints in the early universe are not as stringent. The rapid oscillation induced in G also produces an additional contribution to the Friedman equation that behaves like an effective energy density with a stiff equation of state, but we show that, under reasonable assumptions, this effective energy density is always smaller than the density of the scalar field itself.
Dark energy in scalar-tensor theories
Energy Technology Data Exchange (ETDEWEB)
Moeller, J.
2007-12-15
We investigate several aspects of dynamical dark energy in the framework of scalar-tensor theories of gravity. We provide a classification of scalar-tensor coupling functions admitting cosmological scaling solutions. In particular, we recover that Brans-Dicke theory with inverse power-law potential allows for a sequence of background dominated scaling regime and scalar field dominated, accelerated expansion. Furthermore, we compare minimally and non-minimally coupled models, with respect to the small redshift evolution of the dark energy equation of state. We discuss the possibility to discriminate between different models by a reconstruction of the equation-of-state parameter from available observational data. The non-minimal coupling characterizing scalar-tensor models can - in specific cases - alleviate fine tuning problems, which appear if (minimally coupled) quintessence is required to mimic a cosmological constant. Finally, we perform a phase-space analysis of a family of biscalar-tensor models characterized by a specific type of {sigma}-model metric, including two examples from recent literature. In particular, we generalize an axion-dilaton model of Sonner and Townsend, incorporating a perfect fluid background consisting of (dark) matter and radiation. (orig.)
Kerr black holes with scalar hair.
Herdeiro, Carlos A R; Radu, Eugen
2014-06-06
We present a family of solutions of Einstein's gravity minimally coupled to a complex, massive scalar field, describing asymptotically flat, spinning black holes with scalar hair and a regular horizon. These hairy black holes (HBHs) are supported by rotation and have no static limit. Besides mass M and angular momentum J, they carry a conserved, continuous Noether charge Q measuring the scalar hair. HBHs branch off from the Kerr metric at the threshold of the superradiant instability and reduce to spinning boson stars in the limit of vanishing horizon area. They overlap with Kerr black holes for a set of (M, J) values. A single Killing vector field preserves the solutions, tangent to the null geodesic generators of the event horizon. HBHs can exhibit sharp physical differences when compared to the Kerr solution, such as J/M^{2}>1, a quadrupole moment larger than J^{2}/M, and a larger orbital angular velocity at the innermost stable circular orbit. Families of HBHs connected to the Kerr geometry should exist in scalar (and other) models with more general self-interactions.
Vast Antimatter Regions and Scalar Condensate Baryogenesis
Kirilova, D.; Panayotova, M.; Valchanov, T
2002-01-01
The possibility of natural and abundant creation of antimatter in the Universe in a SUSY-baryogenesis model with a scalar field condensate is described. This scenario predicts vast quantities of antimatter, corresponding to galaxy and galaxy cluster scales today, separated from the matter ones by baryonically empty voids. Theoretical and observational constraints on such antimatter regions are discussed.
Update on scalar singlet dark matter
Cline, J.M.; Scott, P.; Kainulainen, K.; Weniger, C.
2013-01-01
One of the simplest models of dark matter is where a scalar singlet field S comprises some or all of the dark matter and interacts with the standard model through an vertical bar H vertical bar S-2(2) coupling to the Higgs boson. We update the present limits on the model from LHC searches for
Exact solutions for the biadjoint scalar field
Energy Technology Data Exchange (ETDEWEB)
White, C.D., E-mail: Christopher.White@glasgow.ac.uk [School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); Centre for Research in String Theory, Queen Mary University of London, London E1 4NS (United Kingdom)
2016-12-10
Biadjoint scalar theories are novel field theories that arise in the study of non-abelian gauge and gravity amplitudes. In this short paper, we present exact nonperturbative solutions of the field equations, and compare their properties with monopole-like solutions in non-abelian gauge theory. Our results may pave the way for nonperturbative studies of the double copy.
Kundt spacetimes minimally coupled to scalar field
Energy Technology Data Exchange (ETDEWEB)
Tahamtan, T. [Charles University, Institute of Theoretical Physics, Faculty of Mathematics and Physics, Prague 8 (Czech Republic); Astronomical Institute, Czech Academy of Sciences, Prague (Czech Republic); Svitek, O. [Charles University, Institute of Theoretical Physics, Faculty of Mathematics and Physics, Prague 8 (Czech Republic)
2017-06-15
We derive an exact solution belonging to the Kundt class of spacetimes both with and without a cosmological constant that are minimally coupled to a free massless scalar field. We show the algebraic type of these solutions and give interpretation of the results. Subsequently, we look for solutions additionally containing an electromagnetic field satisfying nonlinear field equations. (orig.)
The scalar field kernel in cosmological spaces
Koksma, J.F.; Prokopec, T.|info:eu-repo/dai/nl/326113398; Rigopoulos, G.I.
2008-01-01
We construct the quantum mechanical evolution operator in the Functional Schrodinger picture - the kernel - for a scalar field in spatially homogeneous FLRW spacetimes when the field is a) free and b) coupled to a spacetime dependent source term. The essential element in the construction is the
Using a scalar parameter to trace dislocation evolution in atomistic modeling
Energy Technology Data Exchange (ETDEWEB)
Yang, Jinbo [ORNL; Zhang, Z F [Shenyang National Laboratory for Materials Science; Osetskiy, Yury N [ORNL; Stoller, Roger E [ORNL
2015-01-01
A scalar gamma-parameter is proposed from the Nye tensor. Its maximum value occurs along a dislocation line, either straight or curved, when the coordinate system is purposely chosen. This parameter can be easily obtained from the Nye tensor calculated at each atom in atomistic modeling. Using the gamma-parameter, a fully automated approach is developed to determine core atoms and the Burgers vectors of dislocations simultaneously. The approach is validated by revealing the smallest dislocation loop and by tracing the whole formation process of complicated dislocation networks on the fly.
Brane solutions sourced by a scalar with vanishing potential and classification of scalar branes
Energy Technology Data Exchange (ETDEWEB)
Cadoni, Mariano [Dipartimento di Fisica, Università di Cagliari,Cittadella Universitaria, 09042 Monserrato (Italy); INFN, Sezione di Cagliari,Cagliari (Italy); Franzin, Edgardo [Dipartimento di Fisica, Università di Cagliari,Cittadella Universitaria, 09042 Monserrato (Italy); INFN, Sezione di Cagliari,Cagliari (Italy); CENTRA, Departamento de Física, Instituto Superior Técnico, Universidade de Lisboa,Avenida Rovisco Pais 1, 1049 Lisboa (Portugal); Serra, Matteo [Dipartimento di Matematica, Sapienza Università di Roma,Piazzale Aldo Moro 2, 00185 Roma (Italy)
2016-01-20
We derive exact brane solutions of minimally coupled Einstein-Maxwell-scalar gravity in d+2 dimensions with a vanishing scalar potential and we show that these solutions are conformal to the Lifshitz spacetime whose dual QFT is characterized by hyperscaling violation. These solutions, together with the AdS brane and the domain wall sourced by an exponential potential, give the complete list of scalar branes sourced by a generic potential having simple (scale-covariant) scaling symmetries not involving Galilean boosts. This allows us to give a classification of both simple and interpolating brane solution of minimally coupled Einstein-Maxwell-scalar gravity having no Schrödinger isometries, which may be very useful for holographic applications.
Scalar Implicatures: The psychological reality of scales
Directory of Open Access Journals (Sweden)
Alex de Carvalho
2016-10-01
Full Text Available Scalar implicatures, the phenomena where a sentence like The pianist played some Mozart sonatas is interpreted as The pianist did not play all Mozart sonatas have been given two different analyses. Neo-Griceans claim that this interpretation is based on lexical scales (e.g. , where the stronger term (e.g. all implies the weaker term (e.g. some, but the weaker term (e.g., some implicates the negation of the stronger term (i.e., some = not all. Post-Griceans deny that this is the case and offer a context-based inferential account for scalar implicatures. While scalar implicatures have been extensively investigated, with results apparently in favor of post-Gricean accounts, the psychological reality of lexical scales has not been put to the test. This is what we have done in the present experiment, with a lexical decision task using lexical scales in a masked priming paradigm. While Post-Gricean accounts do not attribute any role for lexical scales in the computation of scalar implicatures, Neo-Gricean accounts suggest that lexical scales are the core mechanism behind the computation of scalar implicatures, and predict that weaker terms in a scale should prime stronger terms more than the reverse because stronger words are necessary to the interpretation of weaker words, while stronger words can be interpreted independently of weaker words. Our results provided evidence in favor of the psychological existence of scales, leading to the first clear experimental support for the Neo-Gricean account.
Dynamics of Scalar field in a Brane World
Mizuno, Shuntaro; Maeda, Kei-ichi; Yamamoto, Kohta
2002-01-01
We study the dynamics of a scalar field in the brane cosmology. We assume that a scalar field is confined in our 4-dimensional world. As for the potential of the scalar field, we discuss three typical models: (1) a power-law potential, (2) an inverse-power-law potential, and (3) an exponential potential. We show that the behavior of the scalar field is very different from a conventional cosmology when the energy density square term is dominated.
I-DWRL: Improved Dual Wireless Radio Localization Using Magnetometer.
Aziz, Abdul; Kumar, Ramesh; Joe, Inwhee
2017-11-15
In the dual wireless radio localization (DWRL) technique each sensor node is equipped with two ultra-wide band (UWB) radios; the distance between the two radios is a few tens of centimeters. For localization, the DWRL technique must use at least two pre-localized nodes to fully localize an unlocalized node. Moreover, in the DWRL technique it is also not possible for two sensor nodes to properly communicate location information unless each of the four UWB radios of two communicating sensor nodes cannot approach the remaining three radios. In this paper, we propose an improved DWRL (I-DWRL) algorithm along with mounting a magnetometer sensor on one of the UWB radios of all sensor nodes. This addition of a magnetometer helps to improve DWRL algorithm such that only one localized sensor node is required for the localization of an unlocalized sensor node, and localization can also be achieved even when some of the four radios of two nodes are unable to communicate with the remaining three radios. The results show that with the use of a magnetometer a greater number of nodes can be localized with a smaller transmission range, less energy and a shorter period of time. In comparison with the conventional DWRL algorithm, our I-DWRL not only maintains the localization error but also requires around half of semi-localizations, 60% of the time, 70% of the energy and a shorter communication range to fully localize an entire network. Moreover, I-DWRL can even localize more nodes while transmission range is not sufficient for DWRL algorithm.
Opportunity Science Using the Juno Magnetometer Investigation Star Trackers
Joergensen, J. L.; Connerney, J. E.; Bang, A. M.; Denver, T.; Oliversen, R. J.; Benn, M.; Lawton, P.
2013-12-01
The magnetometer experiment onboard Juno is equipped with four non-magnetic star tracker camera heads, two of which reside on each of the magnetometer sensor optical benches. These are located 10 and 12 m from the spacecraft body at the end of one of the three solar panel wings. The star tracker, collectively referred to as the Advanced Stellar Compass (ASC), provides high accuracy attitude information for the magnetometer sensors throughout science operations. The star tracker camera heads are pointed +/- 13 deg off the spin vector, in the anti-sun direction, imaging a 13 x 20 deg field of view every ¼ second as Juno rotates at 1 or 2 rpm. The ASC is a fully autonomous star tracker, producing a time series of attitude quaternions for each camera head, utilizing a suite of internal support functions. These include imaging capabilities, autonomous object tracking, automatic dark-sky monitoring, and related capabilities; these internal functions may be accessed via telecommand. During Juno's cruise phase, this capability can be tapped to provide unique science and engineering data available along the Juno trajectory. We present a few examples of the JUNO ASC opportunity science here. As the Juno spacecraft approached the Earth-Moon system for the close encounter with the Earth on October 9, 2013, one of the ASC camera heads obtained imagery of the Earth-Moon system while the other three remained in full science (attitude determination) operation. This enabled the first movie of the Earth and Moon obtained by a spacecraft flying past the Earth in gravity assist. We also use the many artificial satellites in orbit about the Earth as calibration targets for the autonomous asteroid detection system inherent to the ASC autonomous star tracker. We shall also profile the zodiacal dust disk, using the interstellar image data, and present the outlook for small asteroid body detection and distribution being performed during Juno's passage from Earth flyby to Jovian orbit
Black holes with surrounding matter in scalar-tensor theories.
Cardoso, Vitor; Carucci, Isabella P; Pani, Paolo; Sotiriou, Thomas P
2013-09-13
We uncover two mechanisms that can render Kerr black holes unstable in scalar-tensor gravity, both associated with the presence of matter in the vicinity of the black hole and the fact that this introduces an effective mass for the scalar. Our results highlight the importance of understanding the structure of spacetime in realistic, astrophysical black holes in scalar-tensor theories.
Compressibility Effects on the Passive Scalar Flux Within Homogeneous Turbulence
Blaisdell, G. A.; Mansour, N. N.; Reynolds, W. C.
1994-01-01
Compressibility effects on turbulent transport of a passive scalar are studied within homogeneous turbulence using a kinematic decomposition of the velocity field into solenoidal and dilatational parts. It is found that the dilatational velocity does not produce a passive scalar flux, and that all of the passive scalar flux is due to the solenoidal velocity.
Miniature scientific-grade induction magnetometer for cubesats
Pronenko, Vira
2017-04-01
One of the main areas of space research is the study and forecasting of space weather. The society is more and more depending nowadays on satellite technology and communications, so it is vital to understand the physical process in the solar-terrestrial system which may disturb them. Besides the solar radiation and Space Weather effects, the Earth's ionosphere is also modified by the ever increasing industrial activity. There have been also multiple reports relating VLF and ELF wave activity to atmospheric storms and geological processes, such as earthquakes and volcanic activity. For advancing in these fields, the AC magnetic field permanent monitoring is crucial. Using the cubesat technology would allow increasing the number of measuring points dramatically. It is necessary to mention that the cubesats use for scientific research requires the miniaturization of scientific sensors what is a serious problem because the reduction of their dimensions leads, as a rule, to the parameters degradation, especially of sensitivity threshold. Today, there is no basic model of a sensitive miniature induction magnetometer. Even the smallest one of the known - for the Bepi-Colombo mission to Mercury - is too big for cubesats. The goal of the present report is to introduce the new design of miniature three-component sensor for measurement of alternative vector magnetic fields - induction magnetometer (IM). The study directions were concentrated on the ways and possibilities to create the miniature magnetometer with best combination of parameters. For this a set of scientific and technological problems, mostly aimed at the sensor construction improvement, was solved. The most important parameter characterizing magnetometer quality is its own magnetic noise level (NL). The analysis of the NL influencing factors is made and the ways to decrease it are discussed in the report. Finally, the LEMI-151 IM was developed for the SEAM cubesat mission with optimal performances within the
Poly-SiGe-based MEMS Xylophone Bar Magnetometer
Rochus, Véronique; Jansen, R.; Tilmans, H. A. C.; Rottenberg, X.; Chen, C.; Ranvier, S.; Lamy, Hervé; Rochus, Pierre
2012-01-01
This paper presents the design, fabrication and preliminary characterization of highly sensitive MEMS-based Xylophone Bar Magnetometers (XBMs) realized in imec’s poly-SiGe MEMS technology. Key for our Lorentz force driven capacitively sensed resonant sensor are the combination of reasonably high Q-factor and conductivity of imec’s poly-SiGe, our optimized multiphysics sensor design targeting the maximization of the Q-factor in a wide temperature range as well as our proprietary monolithic abo...
Effect of mobility devices on orientation sensors that contain magnetometers.
Kendell, Cynthia; Lemaire, Edward D
2009-01-01
Orientation sensors containing magnetometers use the earth's magnetic field as a reference. Ferromagnetic objects may distort this magnetic field, leading to inaccurate orientation output. We explored the viability of these orientation sensors for motion analysis in an assistive mobility device rehabilitative setting. We attached two MTx orientation sensors (XSens; Enschade, the Netherlands), connected to the XBus Master data collection unit (XSens), to a plastic frame such that the relative angle between sensors was constant. We then moved a series of mobility devices in proximity to the plastic frame: two knee-ankle-foot orthoses (aluminum, stainless steel), one ankle-foot orthosis, two transtibial prostheses (exoskeletal, endoskeletal), two walkers (standard, Challenger Low Wide [Evolution Technologies; Port Coquitlam, Canada]), and two wheelchairs (Tango [OrthoFab; Quebec City, Canada], GTi [Quickie; Phoenix, Arizona]). For each mobility device, we calculated the average difference in relative angle between the baseline and peak angles for each of five trials. Errors ranged from less than 0.10 to 35.29 degrees, depending on the mobility device and frame positioning near the device. This demonstrated the large errors that can occur when magnetometer-based orientation sensors with mobility devices are used. While strategic orientation sensor placement on some mobility devices can minimize these errors to an acceptable level, testing protocols should be implemented to verify orientation sensor accuracy for these applications.
SuperDARN scalar radar equations
Berngardt, O I; Potekhin, A P
2016-01-01
The quadratic scalar radar equations are obtained for SuperDARN radars that are suitable for the analysis and interpretation of experimental data. The paper is based on a unified approach to the obtaining radar equations for the monostatic and bistatic sounding with use of hamiltonian optics and ray representation of scalar Green's function and without taking into account the polarization effects. The radar equation obtained is the sum of several terms corresponding to the propagation and scattering over the different kinds of trajectories, depending on their smoothness and the possibility of reflection from the ionosphere. It is shown that the monostatic sounding in the media with significant refraction, unlike the case of refraction-free media, should be analyzed as a combination of monostatic and bistatic scattering. This leads to strong dependence of scattering amplitude on background ionospheric density due to focusing mechanism and appearance of new (bistatic) areas of effective scattering with signific...
Scalar geons in Born-Infeld gravity
Afonso, V. I.; Olmo, Gonzalo J.; Rubiera-Garcia, D.
2017-08-01
The existence of static, spherically symmetric, self-gravitating scalar field solutions in the context of Born-Infeld gravity is explored. Upon a combination of analytical approximations and numerical methods, the equations for a free scalar field (without a potential term) are solved, verifying that the solutions recover the predictions of General Relativity far from the center but finding important new effects in the central regions. We find two classes of objects depending on the ratio between the Schwarzschild radius and a length scale associated to the Born-Infeld theory: massive solutions have a wormhole structure, with their throat at r≈ 2M, while for the lighter configurations the topology is Euclidean. The total energy density of these solutions exhibits a solitonic profile with a maximum peaked away from the center, and located at the throat whenever a wormhole exists. The geodesic structure and curvature invariants are analyzed for the various configurations considered.
Scalar fields in black hole spacetimes
Thuestad, Izak; Khanna, Gaurav; Price, Richard H.
2017-07-01
The time evolution of matter fields in black hole exterior spacetimes is a well-studied subject, spanning several decades of research. However, the behavior of fields in the black hole interior spacetime has only relatively recently begun receiving some attention from the research community. In this paper, we numerically study the late-time evolution of scalar fields in both Schwarzschild and Kerr spacetimes, including the black hole interior. We recover the expected late-time power-law "tails" on the exterior (null infinity, timelike infinity, and the horizon). In the interior region, we find an interesting oscillatory behavior that is characterized by the multipole index ℓ of the scalar field. In addition, we also study the extremal Kerr case and find strong indications of an instability developing at the horizon.
The light scalar mesons as tetraquarks
Directory of Open Access Journals (Sweden)
Gernot Eichmann
2016-02-01
Full Text Available We present a numerical solution of the four-quark Bethe–Salpeter equation for ground-state scalar tetraquarks with JPC=0++. We find that the four-body equation dynamically generates pseudoscalar-meson poles in the Bethe–Salpeter amplitude. The resulting tetraquarks are genuine four-quark states that are dominated by pseudoscalar meson–meson correlations. Diquark–antidiquark contributions are subleading because of their larger mass scale. In the light quark sector, the sensitivity of the tetraquark wave function to the pion poles leads to an isoscalar tetraquark mass Mσ∼350 MeV which is comparable to that of the σ/f0(500. The masses of its multiplet partners κ and a0/f0 follow a similar pattern. This provides support for a tetraquark interpretation of the light scalar meson nonet in terms of ‘meson molecules’.
Development of autonomous magnetometer rotorcraft for wide area assessment
Energy Technology Data Exchange (ETDEWEB)
Roelof Versteeg; Matt Anderson; Les Beard; Eric Corban; Darryl Curley; Jeff Gamey; Ross Johnson; Dwight Junkin; Mark McKay; Jared Salzmann; Mikhail Tchernychev; Suraj Unnikrishnan; Scott Vinson
2010-04-01
Large areas across the United States are potentially contaminated with UXO, with some ranges encompassing tens to hundreds of thousands of acres. Technologies are needed which will allow for cost effective wide area scanning with 1) near 100 % coverage and 2) near 100 % detection of subsurface ordnance or features indicative of subsurface ordnance. The current approach to wide area assessment is a multi-level one, in which medium - altitude fixed wing optical imaging is used for an initial site assessment. This assessment is followed with low altitude manned helicopter based magnetometry. Subsequent to this wide area assessment targeted surface investigations are performed using either towed geophysical sensor arrays or man portable sensors. In order to be an effective tool for small UXO detection, the sensing altitude for magnetic site investigations needs to be on the order of 1 – 3 meters. These altitude requirements mean that manned helicopter surveys will generally only be feasible in large, open and relatively flat terrains. While such surveys are effective in mapping large areas relatively fast there are substantial mobilization/demobilization, staffing and equipment costs associated with these surveys (resulting in costs of approximately $100-$150/acre). In addition, due to the low altitude there are substantial risks to pilots and equipment. Surface towed arrays provide high resolution maps but have other limitations, e.g. in their ability to navigate rough terrain effectively. There is thus a need for other systems which can be used for effective data collection. An UAV (Unmanned Aerial Vehicle) magnetometer platform is an obvious alternative. The motivation behind such a system is that it reduces risk to operators, is lower in initial and Operational and Maintenance (O&M) costs (and can thus potentially be applied to smaller sites) and has the potential of being more effective in terms of detection and possibly characterization (through the use of
The Effective Hamiltonian in the Scalar Electrodynamics
Dineykhan, M D; Zhaugasheva, S A; Sakhyev, S K
2002-01-01
On the basis of an investigation of the asymptotic behaviour of the polarization loop for the scalar particles in the external electromagnetic field the relativistic corrections to the Hamiltonian are determined. The constituent mass of the particles in the bound state is analytically derived. It is shown that the constituent mass of the particles differs from the mass of the particles in the free state. The corrections connected with the Thomas precession have been calculated.
Nonequilibrium perturbation theory for complex scalar fields
Lawrie, I. D.; McKernan, D. B.
1996-01-01
Real-time perturbation theory is formulated for complex scalar fields away from thermal equilibrium in such a way that dissipative effects arising from the absorptive parts of loop diagrams are approximately resummed into the unperturbed propagators. Low order calculations of physical quantities then involve quasiparticle occupation numbers which evolve with the changing state of the field system, in contrast to standard perturbation theory, where these occupation numbers are frozen at their ...
Astrophysical constraints on singlet scalars at LHC
Hertzberg, Mark P.; Masoumi, Ali
2017-04-01
We consider the viability of new heavy gauge singlet scalar particles at colliders such as the LHC . Our original motivation for this study came from the possibility of a new heavy particle of mass ~ TeV decaying significantly into two photons at colliders, such as LHC, but our analysis applies more broadly. We show that there are significant constraints from astrophysics and cosmology on the simplest UV complete models that incorporate such new particles and its associated collider signal. The simplest and most obvious UV complete model that incorporates such signals is that it arises from a new singlet scalar (or pseudo-scalar) coupled to a new electrically charged and colored heavy fermion. Here we show that these new fermions (and anti-fermions) would be produced in the early universe, then form new color singlet heavy mesons with light quarks, obtain a non-negligible freeze-out abundance, and remain in kinetic equilibrium until decoupling. These heavy mesons possess interesting phenomenology, dependent on their charge, including forming new bound states with electrons and protons. We show that a significant number of these heavy states would survive for the age of the universe and an appreciable number would eventually be contained within the earth and solar system. We show that this leads to detectable consequences, including the production of highly energetic events from annihilations on earth, new spectral lines, and, spectacularly, the destabilization of stars. The lack of detection of these consequences rules out such simple UV completions, putting pressure on the viability of such new particles at LHC . To incorporate such a scalar would require either much more complicated UV completions or even further new physics that provides a decay channel for the associated fermion.
Effective action model of dynamically scalarizing binary neutron stars
Sennett, Noah; Shao, Lijing; Steinhoff, Jan
2017-10-01
Gravitational waves can be used to test general relativity (GR) in the highly dynamical strong-field regime. Scalar-tensor theories of gravity are natural alternatives to GR that can manifest nonperturbative phenomena in neutron stars (NSs). One such phenomenon, known as dynamical scalarization, occurs in coalescing binary NS systems. Ground-based gravitational-wave detectors may be sensitive to this effect, and thus could potentially further constrain scalar-tensor theories. This type of analysis requires waveform models of dynamically scalarizing systems; in this work we devise an analytic model of dynamical scalarization using an effective action approach. For the first time, we compute the Newtonian-order Hamiltonian describing the dynamics of a dynamically scalarizing binary in a self-consistent manner. Despite only working to leading order, the model accurately predicts the frequency at which dynamical scalarization occurs. In conjunction with Landau theory, our model allows one to definitively establish dynamical scalarization as a second-order phase transition. We also connect dynamical scalarization to the related phenomena of spontaneous scalarization and induced scalarization; these phenomena are naturally encompassed into our effective action approach.
Ben-Kish, A; Romalis, M V
2010-11-05
Atomic magnetometers have very high absolute precision and sensitivity to magnetic fields but suffer from a fundamental problem: the vectorial or tensorial interaction of light with atoms leads to "dead zones," certain orientations of the magnetic field where the magnetometer loses its sensitivity. We demonstrate a simple polarization modulation scheme that simultaneously creates coherent population trapping (CPT) in orientation and alignment, thereby eliminating dead zones. Using 87Rb in a 10 Torr buffer gas cell we measure narrow, high-contrast CPT transparency peaks for all orientations and also show the absence of systematic effects associated with nonlinear Zeeman splitting.
Development, construction and analysis of the "Ørsted" fluxgate magnetometer
DEFF Research Database (Denmark)
Nielsen, Otto V; Petersen, Jan Raagaard; Primdahl, Fritz
1995-01-01
The experiments and theoretical considerations leading to the construction of a high-performance three-axis fluxgate magnetometer are described. The magnetometer will be used (1996) in the Earth's field mapping satellite named "Ørsted". The fluxgate sensors are based on stress-annealed metallic g...
Preliminary Report: DESiGN and Test Result of KSR-3 Rocket Magnetometers
Directory of Open Access Journals (Sweden)
Hyo-Min Kim
2000-12-01
Full Text Available The solar wind contributes to the formation of unique space environment called the Earth's magnetosphere by various interactions with the Earth's magnetic field. Thus the solar-terrestrial environment affects the Earth's magnetic field, which can be observed with an instrument for the magnetic field measurement, the magnetometer usually mounted on the rocket and the satellite and based on the ground observatory. The magnetometer is a useful instrument for the spacecraft attitude control as well as the Earth's magnetic field measurements for a scientific purpose. In this paper, we present the preliminary design and test results of the two onboard magnetometers of KARI's (Korea Aerospace Research Institute sounding rocket, KSR-3, which will be launched four times during the period of 2001-02. The KSR-3 magnetometers consist of the fluxgate magnetometer, MAG/AIM (Attitude Information Magnetometer for acquiring the rocket flight attitude information, and of the search-coil magnetometer, MAG/SIM (Scientific Investigation Magnetometer for the observation of the Earth's magnetic field fluctuations. With the MAG/AIM, the 3-axis attitude information can be acquired by the comparison of the resulting dc magnetic vector field with the IGRF (International Geomagnetic Reference Field. The Earth's magnetic field fluctuations ranging from 10 to 1,000 Hz can also be observed with the MAG/SIM measurement.
Minazzoli, Olivier
2013-01-01
The post-Newtonian parameter \\gamma\\ resulting from a universal scalar/matter coupling is investigated in Brans-Dicke-like Scalar-Tensor theories where the scalar potential is assumed to be negligible. Conversely to previous studies, we use a perfect fluid formalism in order to get the explicit scalar-field equation. It is shown that the metric can be put in its standard post-Newtonian form. However, it is pointed out that 1-\\gamma\\ could be either positive, null or negative for finite value of \\omega_0, depending on the coupling function; while Scalar-Tensor theories without coupling always predict \\gamma<1 for finite value of \\omega_0.
Integrated microchip incorporating atomic magnetometer and microfluidic channel for NMR and MRI
Ledbetter, Micah P [Oakland, CA; Savukov, Igor M [Los Alamos, NM; Budker, Dmitry [El Cerrito, CA; Shah, Vishal K [Plainsboro, NJ; Knappe, Svenja [Boulder, CO; Kitching, John [Boulder, CO; Michalak, David J [Berkeley, CA; Xu, Shoujun [Houston, TX; Pines, Alexander [Berkeley, CA
2011-08-09
An integral microfluidic device includes an alkali vapor cell and microfluidic channel, which can be used to detect magnetism for nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI). Small magnetic fields in the vicinity of the vapor cell can be measured by optically polarizing and probing the spin precession in the small magnetic field. This can then be used to detect the magnetic field of in encoded analyte in the adjacent microfluidic channel. The magnetism in the microfluidic channel can be modulated by applying an appropriate series of radio or audio frequency pulses upstream from the microfluidic chip (the remote detection modality) to yield a sensitive means of detecting NMR and MRI.
Correlation between fluxgate and SQUID magnetometer data sets for geomagnetic storms
Directory of Open Access Journals (Sweden)
Matladi Thabang
2014-01-01
Full Text Available There has always been a need to monitor the near Earth's magnetic field, as this monitoring provides understanding and possible predictions of Space Weather events such as geomagnetic storms. Conventional magnetometers such as fluxgates have been used for decades for Space Weather research. The use of highly sensitive magnetometers such as Superconducting QUantum Interference Devices (SQUIDs, promise to give more insight into Space Weather. SQUIDs are relatively recent types of magnetometers that exploit the superconductive effects of flux quantization and Josephson tunneling to measure magnetic flux. SQUIDs have a very broad bandwidth compared to most conventional magnetometers and can measure magnetic flux as low as a few femtotesla. Since SQUIDs have never been used in Space Weather research, unshielded, it is necessary to investigate if they can be reliable Space Weather instruments. The validation is performed by comparing the frequency content of the SQUID and fluxgate magnetometers, as reported by Phiri.
Magnetometer-augmented IMU simulator: in-depth elaboration.
Brunner, Thomas; Lauffenburger, Jean-Philippe; Changey, Sébastien; Basset, Michel
2015-03-04
The location of objects is a growing research topic due, for instance, to the expansion of civil drones or intelligent vehicles. This expansion was made possible through the development of microelectromechanical systems (MEMS), inexpensive and miniaturized inertial sensors. In this context, this article describes the development of a new simulator which generates sensor measurements, giving a specific input trajectory. This will allow the comparison of pose estimation algorithms. To develop this simulator, the measurement equations of every type of sensor have to be analytically determined. To achieve this objective, classical kinematic equations are used for the more common sensors, i.e., accelerometers and rate gyroscopes. As nowadays, the MEMS inertial measurement units (IMUs) are generally magnetometer-augmented, an absolute world magnetic model is implemented. After the determination of the perfect measurement (through the error-free sensor models), realistic error models are developed to simulate real IMU behavior. Finally, the developed simulator is subjected to different validation tests.
Associating ground magnetometer observations with current or voltage generators
DEFF Research Database (Denmark)
Hartinger, M. D.; Xu, Z.; Clauer, C. R.
2017-01-01
A circuit analogy for magnetosphere-ionosphere current systems has two extremes for driversof ionospheric currents: ionospheric elec tric ﬁelds/voltages constant while current/conductivity vary—the“voltage generator”—and current constant while electric ﬁeld/conductivity vary—the “current generator.......”Statistical studies of ground magnetometer observations associated with dayside Transient High LatitudeCurrent Systems (THLCS) driven by similar mechanisms ﬁnd contradictory results using this paradigm:some studies associate THLCS with voltage generators, others with current generators. We argue that mostof...... these two assumptions substantially alter expectations for magnetic perturbations associatedwith either a current or a voltage generator. Our results demonstrate that before interpreting groundmagnetometer observations of THLCS in the context of current/voltage generators, the location...
Construction and Operation of a Differential Hall Element Magnetometer
Calkins, Matthew W.; Javernick, Philip D.; Quintero, Pedro A.; Calm, Yitzi M.; Meisel, Mark W.
2012-02-01
A Differential Hall Element Magnetometer (DHEM) was constructed to measure the magnetic saturation and coercive fields of small samples consisting of magnetic nanoparticles that may have biomedical applications. The device consists of two matched Hall elements that can be moved through the room temperature bore of a 9 Tesla superconducting magnet. The Hall elements are wired in opposition such that a null response, to within a small offset, is measured in the absence of a sample that may be located on top of one unit. A LabVIEW program controls the current through the Hall elements and measures the net Hall voltage while simultaneously moving the probe through the magnetic field by regulating a linear stepper motor. Ultimately, the system will be tested to obtain a figure of merit using successively smaller samples. Details of the apparatus will be provided along with preliminary data.
Magnetometer-Augmented IMU Simulator: In-Depth Elaboration
Directory of Open Access Journals (Sweden)
Thomas Brunner
2015-03-01
Full Text Available The location of objects is a growing research topic due, for instance, to the expansion of civil drones or intelligent vehicles. This expansion was made possible through the development of microelectromechanical systems (MEMS, inexpensive and miniaturized inertial sensors. In this context, this article describes the development of a new simulator which generates sensor measurements, giving a specific input trajectory. This will allow the comparison of pose estimation algorithms. To develop this simulator, the measurement equations of every type of sensor have to be analytically determined. To achieve this objective, classical kinematic equations are used for the more common sensors, i.e., accelerometers and rate gyroscopes. As nowadays, the MEMS inertial measurement units (IMUs are generally magnetometer-augmented, an absolute world magnetic model is implemented. After the determination of the perfect measurement (through the error-free sensor models, realistic error models are developed to simulate real IMU behavior. Finally, the developed simulator is subjected to different validation tests.
Benchtop time-resolved magneto-optical Kerr magnetometer.
Barman, Anjan; Kimura, T; Otani, Y; Fukuma, Y; Akahane, K; Meguro, S
2008-12-01
We present here the construction and application of a compact benchtop time-resolved Kerr magnetometer to measure the magnetization precession in magnetic thin films and lithographically patterned elements. As opposed to very expensive femtosecond lasers this system is built upon a picosecond pulsed injection diode laser and electronic pulse and delay generators. The precession is triggered by the electronic pulses of controlled duration and shape, which is launched onto the sample by a microstrip line. We used polarized optical pulses synchronous to the electronic pulses to measure the magneto-optical Kerr rotation. The system is integrated in a conventional upright microscope configuration with separate illumination, imaging, and magneto-optical probe paths. The system offers high stability, relative ease of alignment, sample changing, and a long range of time delay. We demonstrate the measurements of time-resolved dynamics of a Permalloy microwire and microdot using this system, which showed dynamics at two different time scales.
The Search-coil Magnetometer for the THOR mission
Sahraoui, Fouad; Jannet, Guillaume; Pinçon, Jean-louis; Mansour, Malik; Chalumeau, Gilles; Chabassière, Michel; Hachemi, Tedjani; Jeandet, Alexis; Henri, Pierre; Le Contel, Olivier; Rezeau, Laurence
2017-04-01
Turbulence Heating ObserveR (THOR) is the first mission ever flown in space that is fully dedicated to plasma turbulence. The search-coil magnetometer (SCM) of THOR is a triaxial dual-band antenna dedicated to measuring the magnetic field fluctuations in the frequency range [1Hz,4kHz] and [1,200]kHz. THOR/SCM has a long heritage from earlier space missions such as Cluster, Themis, MMS, BepiColombo, Taranis, Solar orbiter and Solar Probe. In comparison to those missions, the SCM of THOR has a higher sensitivity level, which makes it capable of measuring very low amplitude magnetic fluctuations, in particular in the solar wind. Those measurements are crucial to address the problem of turbulence and energy dissipation at electron scales, a central goal of the THOR mission.
Measuring miniature eye movements by means of a SQUID magnetometer
Peters, M. J.; Dunajski, Z.; Meijzssen, T. E. M.; Breukink, E. W.; Wevers-Henke, J. J.
A new technique to measure small eye movements is reported. The precise recording of human eye movements is necessary for research on visual fatigue induced by visual display units. 1 So far all methods used have disadvantages: especially those which are sensitive or are rather painful. 2,3 Our method is based on a transformation of mechanical vibrations into magnetic flux variations. In order to do this a small magnet is embedded in a close-fitting soft contact lens. The magnetic flux variations caused by eyeball movements during fixation are measured by means of a SQUID magnetometer. The recordings show the typical fixation pattern of a human eye. This pattern is composed of three kinds of movements: saccades, drift and microtremor. The last-mentioned type of movements are displacements in the order of 2 μm. It is possible to distinguish between movements which are perpendicular to each other.
First Results of the Juno Magnetometer Investigation in Jupiter's Magnetosphere
Connerney, Jack; Oliversen, Ronald; Espley, Jared; Kotsiaros, Stavros; Joergensen, John; Joergensen, Peter; Merano, Jose; Denver, Troelz; Benn, Mathias; Bloxham, Jeremy; Bolton, Scott; Levin, Steve
2017-04-01
The Juno spacecraft entered polar orbit about Jupiter on July 4, 2016, after a Jupiter Orbit Insertion (JOI) main engine burn lasting 35 minutes. Juno's science instruments were not powered during the critical maneuver sequence ( 5 days) but were fully operational shortly afterward. The 53.5-day capture orbit provides Juno's science instruments with the opportunity to sample the Jovian environment close up (to 1.06 Jovian radii, Rj) and in polar orbit extending to the outer reaches of the Jovian magnetosphere. Jupiter's gravity and magnetic fields will be globally mapped with unprecedented accuracy as Juno conducts a study of Jupiter's interior structure and composition, as well as the first comprehensive exploration of the polar magnetosphere. The magnetic field investigation onboard Juno is equipped with two magnetometer sensor suites, located at 10 and 12 m from the spacecraft body at the end of one of the three solar panel wings. Each contains a vector fluxgate magnetometer (FGM) sensor and a pair of co-located non-magnetic star tracker camera heads which provide accurate attitude determination for the FGM sensors. The first few periapsis passes available to date revealed an extraordinary spatial variation of the magnetic field close to the planet's surface, suggesting that Juno may be sampling the field closer to the dynamo region than widely anticipated, i.e., portending a dynamo surface extending to relatively large radial distance ( 0.9Rj?). We present the first observations of Jupiter's magnetic field obtained in close proximity to the planet, and speculate on what wonders await as more longitudes are drawn across the global map (32 polar orbits separated by <12° longitude) that the Juno mission was designed to acquire.
Search for Scalar Top and Scalar Bottom Quarks at $\\sqrt{s}$ = 189 GeV at LEP
Abbiendi, G.; Alexander, G.; Allison, John; Altekamp, N.; Anderson, K.J.; Anderson, S.; Arcelli, S.; Asai, S.; Ashby, S.F.; Axen, D.; Azuelos, G.; Ball, A.H.; Barberio, E.; Barlow, Roger J.; Batley, J.R.; Baumann, S.; Bechtluft, J.; Behnke, T.; Bell, Kenneth Watson; Bella, G.; Bellerive, A.; Bentvelsen, S.; Bethke, S.; Betts, S.; Biebel, O.; Biguzzi, A.; Blobel, V.; Bloodworth, I.J.; Bock, P.; Bohme, J.; Bonacorsi, D.; Boutemeur, M.; Braibant, S.; Bright-Thomas, P.; Brigliadori, L.; Brown, Robert M.; Burckhart, H.J.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, David G.; Chrisman, D.; Ciocca, C.; Clarke, P.E.L.; Clay, E.; Cohen, I.; Conboy, J.E.; Cooke, O.C.; Couyoumtzelis, C.; Coxe, R.L.; Cuffiani, M.; Dado, S.; Dallavalle, G.Marco; Davis, R.; De Jong, S.; de Roeck, A.; Dervan, P.; Desch, K.; Dienes, B.; Dixit, M.S.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Estabrooks, P.G.; Etzion, E.; Fabbri, F.; Fanfani, A.; Fanti, M.; Faust, A.A.; Fiedler, F.; Fierro, M.; Fleck, I.; Folman, R.; Frey, A.; Furtjes, A.; Futyan, D.I.; Gagnon, P.; Gary, J.W.; Gascon, J.; Gascon-Shotkin, S.M.; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Gibson, V.; Gibson, W.R.; Gingrich, D.M.; Glenzinski, D.; Goldberg, J.; Gorn, W.; Grandi, C.; Graham, K.; Gross, E.; Grunhaus, J.; Gruwe, M.; Hanson, G.G.; Hansroul, M.; Hapke, M.; Harder, K.; Harel, A.; Hargrove, C.K.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Herndon, M.; Herten, G.; Heuer, R.D.; Hildreth, M.D.; Hill, J.C.; Hobson, P.R.; Hoch, M.; Hocker, James Andrew; Hoffman, Kara Dion; Homer, R.J.; Honma, A.K.; Horvath, D.; Hossain, K.R.; Howard, R.; Huntemeyer, P.; Igo-Kemenes, P.; Imrie, D.C.; Ishii, K.; Jacob, F.R.; Jawahery, A.; Jeremie, H.; Jimack, M.; Jones, C.R.; Jovanovic, P.; Junk, T.R.; Kanzaki, J.; Karlen, D.; Kartvelishvili, V.; Kawagoe, K.; Kawamoto, T.; Kayal, P.I.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Kim, D.H.; Klier, A.; Kobayashi, T.; Kobel, M.; Kokott, T.P.; Kolrep, M.; Komamiya, S.; Kowalewski, Robert V.; Kress, T.; Krieger, P.; von Krogh, J.; Kuhl, T.; Kyberd, P.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Lauber, J.; Lautenschlager, S.R.; Lawson, I.; Layter, J.G.; Lee, A.M.; Lellouch, D.; Letts, J.; Levinson, L.; Liebisch, R.; List, B.; Littlewood, C.; Lloyd, A.W.; Lloyd, S.L.; Loebinger, F.K.; Long, G.D.; Losty, M.J.; Lu, J.; Ludwig, J.; Lui, D.; Macchiolo, A.; Macpherson, A.; Mader, W.; Mannelli, M.; Marcellini, S.; Markopoulos, C.; Martin, A.J.; Martin, J.P.; Martinez, G.; Mashimo, T.; Mattig, Peter; McDonald, W.John; McKenna, J.; Mckigney, E.A.; McMahon, T.J.; McPherson, R.A.; Meijers, F.; Menke, S.; Merritt, F.S.; Mes, H.; Meyer, J.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Mir, R.; Mohr, W.; Montanari, A.; Mori, T.; Nagai, K.; Nakamura, I.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oakham, F.G.; Odorici, F.; Ogren, H.O.; Oreglia, M.J.; Orito, S.; Palinkas, J.; Pasztor, G.; Pater, J.R.; Patrick, G.N.; Patt, J.; Perez-Ochoa, R.; Petzold, S.; Pfeifenschneider, P.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poffenberger, P.; Poli, B.; Polok, J.; Przybycien, M.; Rembser, C.; Rick, H.; Robertson, S.; Robins, S.A.; Rodning, N.; Roney, J.M.; Rosati, S.; Roscoe, K.; Rossi, A.M.; Rozen, Y.; Runge, K.; Runolfsson, O.; Rust, D.R.; Sachs, K.; Saeki, T.; Sahr, O.; Sang, W.M.; Sarkisian, E.K.G.; Sbarra, C.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schmitt, S.; Schoning, A.; Schroder, Matthias; Schumacher, M.; Schwick, C.; Scott, W.G.; Seuster, R.; Shears, T.G.; Shen, B.C.; Shepherd-Themistocleous, C.H.; Sherwood, P.; Siroli, G.P.; Sittler, A.; Skuja, A.; Smith, A.M.; Snow, G.A.; Sobie, R.; Soldner-Rembold, S.; Spagnolo, S.; Sproston, M.; Stahl, A.; Stephens, K.; Steuerer, J.; Stoll, K.; Strom, David M.; Strohmer, R.; Surrow, B.; Talbot, S.D.; Taras, P.; Tarem, S.; Teuscher, R.; Thiergen, M.; Thomas, J.; Thomson, M.A.; Torrence, E.; Towers, S.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turcot, A.S.; Turner-Watson, M.F.; Ueda, I.; Van Kooten, Rick J.; Vannerem, P.; Verzocchi, M.; Voss, H.; Wackerle, F.; Wagner, A.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wermes, N.; White, J.S.; Wilson, G.W.; Wilson, J.A.; Wyatt, T.R.; Yamashita, S.; Yekutieli, G.; Zacek, V.; Zer-Zion, D.
1999-01-01
Searches for a scalar top quark and a scalar bottom quark have been performed using a data sample of 182 pb-1 at a centre-of-mass energy of 189 GeV collected with the OPAL detector at LEP. No evidence for a signal was found. The 95% confidence level lower limit on the scalar top quark mass is 90.3 GeV if the mixing angle between the supersymmetric partners of the left- and right-handed states of the top quark is zero. In the worst case, when the scalar top quark decouples from the Z boson, the lower limit is 87.2 GeV. These limits were obtained assuming that the scalar top quark decays into a charm quark and the lightest neutralino, and that the mass difference between the scalar top quark and the lightest neutralino is larger than 10 GeV. The complementary decay mode of the scalar top quark decaying into a bottom quark, a charged lepton and a scalar neutrino has also been studied. From a search for the scalar bottom quark, a mass limit of 88.6 GeV was obtained if the mass difference between the scalar bottom...
Scalar Potential Model of photon diffraction
Hodge, John
2011-04-01
Some observations of light are inconsistent with a wave-like model. Other observations of light are inconsistent with a traditional particle-like model. A single model of light has remained a mystery. Newton's speculations, Democritus's speculations, the Bohm interpretation, and the fractal philosophy are combined with the cosmological Scalar Potential Model (SPM). The resulting model of photon structure and dynamics is tested by a toy computer experiment. The simulations included light from a distance and Young's experiment. The patterns on the screens showed diffraction wave patterns fit by the Fresnel equation. The model is consistent with the Afshar experiment and with the concepts of Bohmian mechanics.
Scalar-field theory of dark matter
Huang, Kerson; Zhao, Xiaofei
2013-01-01
We develop a theory of dark matter based on a previously proposed picture, in which a complex vacuum scalar field makes the universe a superfluid, with the energy density of the superfluid giving rise to dark energy, and variations from vacuum density giving rise to dark matter. We formulate a nonlinear Klein-Gordon equation to describe the superfluid, treating galaxies as external sources. We study the response of the superfluid to the galaxies, in particular, the emergence of the dark-matter galactic halo, contortions during galaxy collisions, and the creation of vortices due to galactic rotation.
Scalar boundary conditions in hyperscaling violating geometry
Directory of Open Access Journals (Sweden)
Jian-Pin Wu
2016-02-01
Full Text Available We study the possible boundary conditions of scalar field modes in a hyperscaling violation (HV geometry with Lifshitz dynamical exponent z (z≥1 and hyperscaling violation exponent θ (θ≠0. For the case with θ>0, we show that in the parameter range 1≤z≤2, −z+d−12, −z+d−10, which has been addressed in Ref. [1]. Meanwhile, we also carry out the parallel investigation in the case with θ0, only one type is available.
Scalar dissipation rate statistics in turbulent swirling jets
Stetsyuk, V.; Soulopoulos, N.; Hardalupas, Y.; Taylor, A. M. K. P.
2016-07-01
The scalar dissipation rate statistics were measured in an isothermal flow formed by discharging a central jet in an annular stream of swirling air flow. This is a typical geometry used in swirl-stabilised burners, where the central jet is the fuel. The flow Reynolds number was 29 000, based on the area-averaged velocity of 8.46 m/s at the exit and the diameter of 50.8 mm. The scalar dissipation rate and its statistics were computed from two-dimensional imaging of the mixture fraction fields obtained with planar laser induced fluorescence of acetone. Three swirl numbers, S, of 0.3, 0.58, and 1.07 of the annular swirling stream were considered. The influence of the swirl number on scalar mixing, unconditional, and conditional scalar dissipation rate statistics were quantified. A procedure, based on a Wiener filter approach, was used to de-noise the raw mixture fraction images. The filtering errors on the scalar dissipation rate measurements were up to 15%, depending on downstream positions from the burner exit. The maximum of instantaneous scalar dissipation rate was found to be up to 35 s-1, while the mean dissipation rate was 10 times smaller. The probability density functions of the logarithm of the scalar dissipation rate fluctuations were found to be slightly negatively skewed at low swirl numbers and almost symmetrical when the swirl number increased. The assumption of statistical independence between the scalar and its dissipation rate was valid for higher swirl numbers at locations with low scalar fluctuations and less valid for low swirl numbers. The deviations from the assumption of statistical independence were quantified. The conditional mean of the scalar dissipation rate, the standard deviation of the scalar dissipation rate fluctuations, the weighted probability of occurrence of the mean conditional scalar dissipation rate, and the conditional probability are reported.
Spectra of turbulently advected scalars that have small Schmidt number
Hill, Reginald J.
2017-09-01
Exact statistical equations are derived for turbulent advection of a passive scalar having diffusivity much larger than the kinematic viscosity, i.e., small Schmidt number. The equations contain all terms needed for precise direct numerical simulation (DNS) quantification. In the appropriate limit, the equations reduce to the classical theory for which the scalar spectrum is proportional to the energy spectrum multiplied by k-4, which, in turn, results in the inertial-diffusive range power law, k-17 /3. The classical theory was derived for the case of isotropic velocity and scalar fields. The exact equations are simplified for less restrictive cases: (1) locally isotropic scalar fluctuations at dissipation scales with no restriction on symmetry of the velocity field, (2) isotropic velocity field with averaging over all wave-vector directions with no restriction on the symmetry of the scalar, motivated by that average being used for DNS, and (3) isotropic velocity field with axisymmetric scalar fluctuations, motivated by the mean-scalar-gradient-source case. The equations are applied to recently published DNSs of passive scalars for the cases of a freely decaying scalar and a mean-scalar-gradient source. New terms in the exact equations are estimated for those cases and are found to be significant; those terms cause the deviations from the classical theory found by the DNS studies. A new formula for the mean-scalar-gradient case explains the variation of the scalar spectra for the DNS of the smallest Schmidt-number cases. Expansion in Legendre polynomials reveals the effect of axisymmetry. Inertial-diffusive-range formulas for both the zero- and second-order Legendre contributions are given. Exact statistical equations reveal what must be quantified using DNS to determine what causes deviations from asymptotic relationships.
Dynamical scalar hair formation around a Schwarzschild black hole
Benkel, Robert; Sotiriou, Thomas P.; Witek, Helvi
2016-12-01
Scalar fields coupled to the Gauss-Bonnet invariant evade the known no-hair theorems and have nontrivial configurations around black holes. We focus on a scalar field that couples linearly to the Gauss-Bonnet invariant and hence exhibits shift symmetry. We study its dynamical evolution and the formation of scalar hair in a Schwarzschild background. We show that the evolution eventually settles to the known static hairy solutions in the appropriate limit.
Massive basketball diagram for a thermal scalar field theory
Andersen, Jens O.; Braaten, Eric; Strickland, Michael
2000-08-01
The ``basketball diagram'' is a three-loop vacuum diagram for a scalar field theory that cannot be expressed in terms of one-loop diagrams. We calculate this diagram for a massive scalar field at nonzero temperature, reducing it to expressions involving three-dimensional integrals that can be easily evaluated numerically. We use this result to calculate the free energy for a massive scalar field with a φ4 interaction to three-loop order.
Kerr-Newman black holes with scalar hair
Delgado, Jorge F. M.; Herdeiro, Carlos A. R.; Radu, Eugen; Rúnarsson, Helgi
2016-10-01
We construct electrically charged Kerr black holes (BHs) with scalar hair. Firstly, we take an uncharged scalar field, interacting with the electromagnetic field only indirectly, via the background metric. The corresponding family of solutions, dubbed Kerr-Newman BHs with ungauged scalar hair, reduces to (a sub-family of) Kerr-Newman BHs in the limit of vanishing scalar hair and to uncharged rotating boson stars in the limit of vanishing horizon. It adds one extra parameter to the uncharged solutions: the total electric charge. This leading electromagnetic multipole moment is unaffected by the scalar hair and can be computed by using Gauss's law on any closed 2-surface surrounding (a spatial section of) the event horizon. By contrast, the first sub-leading electromagnetic multipole - the magnetic dipole moment -, gets suppressed by the scalar hair, such that the gyromagnetic ratio is always smaller than the Kerr-Newman value (g = 2). Secondly, we consider a gauged scalar field and obtain a family of Kerr-Newman BHs with gauged scalar hair. The electrically charged scalar field now stores a part of the total electric charge, which can only be computed by applying Gauss' law at spatial infinity and introduces a new solitonic limit - electrically charged rotating boson stars. In both cases, we analyze some physical properties of the solutions.
The Statistical Model with Interpartial Scalar Conformally Invariant Interaction
Ignat'ev, Yurii
2015-01-01
A closed mathematical model of the statistical self-gravitating system of scalar charged particles for conformal invariant scalar interactions is constructed on the basis of relativistic kinetics and gravitation theory. Asymptotic properties of the model are investigated in the ultrarelativistic limit. It is shown, that scalar charge density automatically generates scalar field effective mass and the value of this mass is found. In the paper it is proved the asymptotic conformal invariance of constitutive equations in case of homogenous isotropic Universe. Also it is proved the asymptotic conformal invariance of field equations at the early stages of cosmological evolution.
Neutron Star Structure in the Presence of Scalar Fields
Kazanas, Demosthenes
2004-01-01
Motivated by the possible presence of scalar fields on astrophysical scales, suggested by the apparent acceleration of the universe implied by the supernovae surveys, we present models of neutron star structure including the contribution of a (massless) scalar field to the stress energy momentum tensor, in addition to that made by the normal matter. To that end we solve the coupled Einstein -- scalar field -- hydrostatic balance equations to compute the effect of the presence of the scalar field on the neutron star structure. We find that the presence of the scalar field does change the structure of the neutron star, especially in cases of strong coupling between the scalar field and the matter density. We present the neutron star radius as a function of the matter--scalar field coupling constant for different values of the neutron star central density. The presence of the scalar field affects both the maximum neutron star mass and Its radius, the latter increasing with the value of the above coupling constant. We also compute particle and photon geodesics in the geometry of these neutron stars as well as to the geometry of black holes with different values of the scalar field. Our results may be testable with timing observations of accreting neutron stars.
Structure scalars and evolution equations in f( G) cosmology
Sharif, M.; Fatima, H. Ismat
2017-01-01
In this paper, we study the dynamics of self-gravitating fluid using structure scalars for spherical geometry in the context of f( G) cosmology. We construct structure scalars through orthogonal splitting of the Riemann tensor and deduce a complete set of equations governing the evolution of dissipative anisotropic fluid in terms of these scalars. We explore different causes of density inhomogeneity which turns out to be a necessary condition for viable models. It is explicitly shown that anisotropic inhomogeneous static spherically symmetric solutions can be expressed in terms of these scalar functions.
Light Higgs from Scalar See-Saw in Technicolor
DEFF Research Database (Denmark)
Foadi, Roshan; Frandsen, Mads Toudal
2012-01-01
We consider a TeV scale see-saw mechanism leading to light scalar resonances in models with otherwise intrinsically heavy scalars. The mechanism can provide a 125 GeV technicolor Higgs in e.g. two-scale TC models......We consider a TeV scale see-saw mechanism leading to light scalar resonances in models with otherwise intrinsically heavy scalars. The mechanism can provide a 125 GeV technicolor Higgs in e.g. two-scale TC models...
Improved constraints on monopole–dipole interaction mediated by pseudo-scalar bosons
Directory of Open Access Journals (Sweden)
N. Crescini
2017-10-01
Full Text Available We present a more stringent upper limit on long-range axion-mediated forces obtained by the QUAX-gpgs experiment, located at the INFN – Laboratori Nazionali di Legnaro. By measuring variations of a paramagnetic GSO crystal magnetization with a dc-SQUID magnetometer we investigate the possible coupling between electron spins and unpolarized nucleons in lead disks. The induced magnetization can be interpreted as the effect of a long-range spin dependent interaction mediated by axions or Axion Like Particles (ALPs. The corresponding coupling strength is proportional to the CP violating term gpegsN, i.e. the product of the pseudoscalar and scalar coupling constants of electron and nucleon, respectively. Our upper limit is more constraining than previous ones in the interaction range 0.01 m<λa<0.2 m, with a best result on gpegsN/(ħc of 4.3×10−30 at 95% confidence level in the interval 0.1 m<λa<0.2 m. We eventually discuss our plans to improve the QUAX-gpgs sensitivity by a few orders of magnitude, which will allow us to investigate the ϑ≃10−10 range of CP-violating parameter and test some QCD axion models.
Spontaneous breakdown and the scalar nonet
Energy Technology Data Exchange (ETDEWEB)
Scadron, M.D.
1982-07-01
In the context of the QCD quark model and on the basis of dynamical Bethe-Salpeter ladder graphs, we suggest that (i) the existence of the scalar q-barq hadron multiplet, like the pseudoscalar q-barq multiplet, is a direct consequence of dynamical spontaneous breakdown of chiral symmetry with a chiral-limiting nonstrange mass scale of m/sub sigmaNS//sup CL/ = 2m/sub dyn/ roughly-equal630 MeV, (ii) the lifting of the nonstrange sigma-delta degeneracy is expected from the s-wave quark-gluon annihilation diagram, and (iii) the observed sigma-S* mixing follows from the existence of the p-wave scalar quark-annihilation diagram. The resulting predicted 0q-barq nonet is then sigma(750 MeV), kappa(800), S*(980), and delta(985), in agreement with data for the resonant masses, the mixing angle, and also decay widths except for the kappa(800).
Noncommutative Complex Scalar Field and Casimir Effect
Khelili, Farid
2012-06-01
Using the noncommutative deformed canonical commutation relations proposed by Carmona et al. [J. M. Carmona, J. L. Cortés, J. Gamboa, and F. Mendez, J. High Energy Phys.JHEPFG1029-8479 03 (2003) 058.10.1088/1126-6708/2003/03/058][J. Gamboa, J. Lopéz-Sarrion, and A. P. Polychronakos, Phys. Lett. B 634, 471 (2006).PYLBAJ0370-269310.1016/j.physletb.2006.02.014][J. M. Carmona, J. L. Cortés, Ashok Das, J. Gamboa, and F. Mendez, Mod. Phys. Lett. A 21, 883 (2006).MPLAEQ0217-732310.1142/S0217732306020111], a model describing the dynamics of the noncommutative complex scalar field is proposed. The noncommutative field equations are solved, and the vacuum energy is calculated to the second order in the parameter of noncommutativity. As an application to this model, the Casimir effect, due to the zero-point fluctuations of the noncommutative complex scalar field, is considered. It turns out that in spite of its smallness, the noncommutativity gives rise to a repulsive force at the microscopic level, leading to a modified Casimir potential with a minimum at the point amin=(5)/(84)πθ.
Unique Fock quantization of scalar cosmological perturbations
Fernández-Méndez, Mikel; Olmedo, Javier; Velhinho, José M
2012-01-01
We investigate the ambiguities in the Fock quantization of the scalar perturbations of a Friedmann-Lema\\^{i}tre-Robertson-Walker model with a massive scalar field as matter content. We consider the case of compact spatial sections (thus avoiding infrared divergences), with the topology of a three-sphere. After expanding the perturbations in series of eigenfunctions of the Laplace-Beltrami operator, the Hamiltonian of the system is written up to quadratic order in them. We fix the gauge of the local degrees of freedom in two different ways, reaching in both cases the same qualitative results. A canonical transformation, which includes the scaling of the matter field perturbations by the scale factor of the geometry, is performed in order to arrive at a convenient formulation of the system. We then study the quantization of these perturbations in the classical background determined by the homogeneous variables. Based on previous work, we introduce a Fock representation for the perturbations in which: (a) the co...
A Scanning Quantum Cryogenic Atom Microscope
Lev, Benjamin
Microscopic imaging of local magnetic fields provides a window into the organizing principles of complex and technologically relevant condensed matter materials. However, a wide variety of intriguing strongly correlated and topologically nontrivial materials exhibit poorly understood phenomena outside the detection capability of state-of-the-art high-sensitivity, high-resolution scanning probe magnetometers. We introduce a quantum-noise-limited scanning probe magnetometer that can operate from room-to-cryogenic temperatures with unprecedented DC-field sensitivity and micron-scale resolution. The Scanning Quantum Cryogenic Atom Microscope (SQCRAMscope) employs a magnetically levitated atomic Bose-Einstein condensate (BEC), thereby providing immunity to conductive and blackbody radiative heating. The SQCRAMscope has a field sensitivity of 1.4 nT per resolution-limited point (2 um), or 6 nT / Hz1 / 2 per point at its duty cycle. Compared to point-by-point sensors, the long length of the BEC provides a naturally parallel measurement, allowing one to measure nearly one-hundred points with an effective field sensitivity of 600 pT / Hz1 / 2 each point during the same time as a point-by-point scanner would measure these points sequentially. Moreover, it has a noise floor of 300 pT and provides nearly two orders of magnitude improvement in magnetic flux sensitivity (down to 10- 6 Phi0 / Hz1 / 2) over previous atomic probe magnetometers capable of scanning near samples. These capabilities are for the first time carefully benchmarked by imaging magnetic fields arising from microfabricated wire patterns and done so using samples that may be scanned, cryogenically cooled, and easily exchanged. We anticipate the SQCRAMscope will provide charge transport images at temperatures from room to \\x9D4K in unconventional superconductors and topologically nontrivial materials.
Semi-analytic stellar structure in scalar-tensor gravity
Horbatsch, M. W.; Burgess, C. P.
2011-08-01
Precision tests of gravity can be used to constrain the properties of hypothetical very light scalar fields, but these tests depend crucially on how macroscopic astrophysical objects couple to the new scalar field. We study the equations of stellar structure using scalar-tensor gravity, with the goal of seeing how stellar properties depend on assumptions made about the scalar coupling at a microscopic level. In order to make the study relatively easy for different assumptions about microscopic couplings, we develop quasi-analytic approximate methods for solving the stellar-structure equations rather than simply integrating them numerically. (The approximation involved assumes the dimensionless scalar coupling at the stellar center is weak, and we compare our results with numerical integration in order to establish its domain of validity.) We illustrate these methods by applying them to Brans-Dicke scalars, and their generalization in which the scalar-matter coupling slowly runs — or `walks' — as a function of the scalar field: a(phi) simeq as+bsphi. (Such couplings can arise in extra-dimensional applications, for instance.) The four observable parameters that characterize the fields external to a spherically symmetric star are the stellar radius, R, mass, M, scalar `charge', Q, and the scalar's asymptotic value, phi∞. These are subject to two relations because of the matching to the interior solution, generalizing the usual mass-radius, M(R), relation of General Relativity. Since phi∞ is common to different stars in a given region (such as a binary pulsar), all quantities can be computed locally in terms of the stellar masses. We identify how these relations depend on the microscopic scalar couplings, agreeing with earlier workers when comparisons are possible. Explicit analytical solutions are obtained for the instructive toy model of constant-density stars, whose properties we compare to more realistic equations of state for neutron star models.
Lamb-Dicke spectroscopy of atoms in a hollow-core photonic crystal fibre
Okaba, Shoichi; Takano, Tetsushi; Benabid, Fetah; Bradley, Tom; Vincetti, Luca; Maizelis, Zakhar; Yampol'skii, Valery; Nori, Franco; Katori, Hidetoshi
2014-01-01
Unlike photons, which are conveniently handled by mirrors and optical fibres without loss of coherence, atoms lose their coherence via atom–atom and atom–wall interactions. This decoherence of atoms deteriorates the performance of atomic clocks and magnetometers, and also hinders their miniaturization. Here we report a novel platform for precision spectroscopy. Ultracold strontium atoms inside a kagome-lattice hollow-core photonic crystal fibre are transversely confined by an optical lattice to prevent atoms from interacting with the fibre wall. By confining at most one atom in each lattice site, to avoid atom–atom interactions and Doppler effect, a 7.8-kHz-wide spectrum is observed for the 1S0−3P1(m=0) transition. Atoms singly trapped in a magic lattice in hollow-core photonic crystal fibres improve the optical depth while preserving atomic coherence time. PMID:24934478
M(H) dependence and size distribution of SPIONs measured by atomic magnetometry
Colombo, Simone; Grujic, Zoran D; Dolgovskiy, Vladimir; Weis, Antoine
2016-01-01
We demonstrate that the quasistatic recording of the magnetic excitation function M(H) of superparamagnetic iron oxide magnetic nanoparticle (SPION) suspensions by an atomic magnetometer allows a precise determination of the sample's iron mass content mFe and the particle size distribution.
IceBridge Flux Gate Magnetometer L0 Raw Magnetic Field
National Aeronautics and Space Administration — The NASA IceBridge Flux Gate Magnetometer L0 Raw Magnetic Field (IMFGM0) data set contains magnetic field readings taken over Antarctica using the Integrity...
In-orbit calibration of the lunar magnetometer onboard SELENE (KAGUYA)
National Research Council Canada - National Science Library
Takahashi, Futoshi; Shimizu, Hisayoshi; Matsushima, Masaki; Shibuya, Hidetoshi; Matsuoka, Ayako; Nakazawa, Satoru; Iijima, Yuichi; Otake, Hisashi; Tsunakawa, Hideo
2009-01-01
The high-sensitivity fluxgate Lunar MAGnetometer (LMAG) is mounted on SELENE (KAGUYA) to investigate the near-surface electromagnetic environment and the evolution of the Moon through magnetic field observation...
Quantum assisted enhancement of optical magnetometer with squeezed vacuum in hot Rb vapor
Mikhailov, Eugeniy; Horrom, Travis; Singh, Robinjeet
2012-06-01
We demonstrate enhancement to the sensitivity of an optical magnetometer based on the nonlinear magneto-optical Faraday effect in ^87Rb vapor with the use of squeezed vacuum. We generate quantum squeezed vacuum states via the polarization self-rotation effect in hot ^87Rb vapor exhibiting noise spectrum suppression ranging from frequencies of a few hundred Hz to several MHz. Injection of such squeezed states into a magneto-optical magnetometer provides broad band noise suppression of close to 2 dB. We study various parameters of the magnetometer such as Rb cell temperature, pump power, and the noise spectrum of the probe signal to identify the most favorable conditions for quantum enhanced magnetometry. Our experimental arrangement offers potential quantum improvement to the most sensitive magnetometers at frequencies down to hundreds of Hz, which can be useful for biological, geophysical, medical, or military sensing applications.
IceBridge Scintrex CS-3 Cesium Magnetometer L0 Raw Magnetic Field
National Aeronautics and Space Administration — The NASA IceBridge Scintrex CS-3 Cesium Magnetometer L0 Raw Magnetic Field data set contains magnetic field readings and fluxgate values taken over Greenland using...
IceBridge Geometrics 823A Cesium Magnetometer L0 Raw Magnetic Field
National Aeronautics and Space Administration — The NASA IceBridge Geometrics 823A Cesium Magnetometer L0 Raw Magnetic Field (IMGEO0) data set contains magnetic field readings taken over Antarctica using the...
IceBridge Flux Gate Magnetometer L0 Raw Magnetic Field, Version 1
National Aeronautics and Space Administration — The NASA IceBridge Flux Gate Magnetometer L0 Raw Magnetic Field (IMFGM0) data set contains magnetic field readings taken over Antarctica using the Integrity...
IceBridge Geometrics 823A Cesium Magnetometer L0 Raw Magnetic Field, Version 1
National Aeronautics and Space Administration — The NASA IceBridge Geometrics 823A Cesium Magnetometer L0 Raw Magnetic Field (IMGEO0) data set contains magnetic field readings taken over Antarctica using the...
IceBridge Geometrics 823A Cesium Magnetometer L2 Geolocated Magnetic Anomalies, Version 1
National Aeronautics and Space Administration — The NASA IceBridge Geometrics 823A Cesium Magnetometer L2 Geolocated Magnetic Anomalies (IMGEO2) data set contains magnetic anomaly measurements taken over...
IceBridge Geometrics 823A Cesium Magnetometer L2 Geolocated Magnetic Anomalies
National Aeronautics and Space Administration — The NASA IceBridge Geometrics 823A Cesium Magnetometer L2 Geolocated Magnetic Anomalies (IMGEO2) data set contains magnetic anomaly measurements taken over...
Rad-Hard Sigma-Delta 3-channel ADC for Fluxgate Magnetometers Project
National Aeronautics and Space Administration — The proposed project aims to develop a multi-channel analog to digital converter (ADC) required for a fluxgate magnetometer (EPD) employed on NASA's planetary...
Integration of a MEMS Inertial Measuring Unit with a MEMS Magnetometer for 3D Orientation Estimation
DEFF Research Database (Denmark)
Cai, Junping; Malureanu, Christian; Andersen, Niels Lervad
2011-01-01
This paper presents an algorithm for combining the measurements of a MEMS Inertial Measurement Unit (IMU) and a MEMS magnetometer. The measurements are done using a special designed and customized miniature detecting system for 3D orientation estimation, and position tracking......This paper presents an algorithm for combining the measurements of a MEMS Inertial Measurement Unit (IMU) and a MEMS magnetometer. The measurements are done using a special designed and customized miniature detecting system for 3D orientation estimation, and position tracking...
Identification of a dynamic atmosphere at Enceladus with the Cassini magnetometer.
Dougherty, M K; Khurana, K K; Neubauer, F M; Russell, C T; Saur, J; Leisner, J S; Burton, M E
2006-03-10
The Cassini magnetometer has detected the interaction of the magnetospheric plasma of Saturn with an atmospheric plume at the icy moon Enceladus. This unanticipated finding, made on a distant flyby, was subsequently confirmed during two follow-on flybys, one very close to Enceladus. The magnetometer data are consistent with local outgassing activity via a plume from the surface of the moon near its south pole, as confirmed by other Cassini instruments.
Calibrating the Swarm: Networked Small Satellite Magnetometers for Auroral Plasma Science
Parham, Jonathan; Van Dessel, Osi; Kromis, Maria; Teng, Phillip; Semeter, Joshua; Zosuls, Alexks; Walsh, Brian
2017-01-01
Motivated by small-scale auroral plasma science, ANDESITE, a 6U CubeSat with eight deployable picosatellites, will fly a network of magnetometers through the Northern Lights. With the spacecraft due to launch on the upcoming ELaNa XIX mission, this work details its science mission architecture along with the payload design and calibration. Each three-axis magnetometer instrument is hosted by a deployable picosatellite about the size of a piece of toast. Calibration of these sensors included a...
M. O. Archer; Horbury, T. S.; Brown, P; Eastwood, J. P.; Oddy, T. M.; B. J. Whiteside; Sample, J. G.
2015-01-01
We present the first in-flight results from a novel miniaturised anisotropic magnetoresistive space magnetometer, MAGIC (MAGnetometer from Imperial College), aboard the first CINEMA (CubeSat for Ions, Neutrals, Electrons and MAgnetic fields) spacecraft in low Earth orbit. An attitude-independent calibration technique is detailed using the International Geomagnetic Reference Field (IGRF), which is temperature dependent in the case of the outboard sensor. We show that the sens...
Variational method for objective analysis of scalar variable and its ...
Indian Academy of Sciences (India)
It has been found that objectively analysed scalar ﬁeld obtained using standard method is superior to the scalar ﬁeld derived by the triangle method,whereas the derivative ﬁelds produced by triangle method are superior to the derivative ﬁelds produced using standard method. A variational objective analysis scheme has ...
Collisionless self-gravitating statistical systems of scalar interacting particles
Ignat'ev, Yu G
2015-01-01
This paper is devoted to consideration of the theory of collisionless statistical systems with interparticle scalar interaction. The mathematical model of such systems is constructed and the exact solution of Vlasov equation for isotropic homogenous model of the Universe is found. Asymptotic solutions of self-consistent Vlasov - Einstein model for conformally invariant scalar interactions are found.
Regular and Chaotic Regimes in Scalar Field Cosmology
Directory of Open Access Journals (Sweden)
Alexey V. Toporensky
2006-03-01
Full Text Available A transient chaos in a closed FRW cosmological model with a scalar field is studied. We describe two different chaotic regimes and show that the type of chaos in this model depends on the scalar field potential. We have found also that for sufficiently steep potentials or for potentials with large cosmological constant the chaotic behavior disappears.
LIPSS results for photons coupling to light neutral scalar bosons
Energy Technology Data Exchange (ETDEWEB)
Andrei Afanasev; Oliver K. Baker; Kevin Beard; George Biallas; James Boyce; Minarni Minarni; Roopchan Ramdon; Michelle D. Shinn; Penny Slocum
2008-06-01
The LIPSS search for a light neutral scalar boson coupling to optical photons is reported. The search covers a region of parameter space of approximately 1.0 meV and coupling strength greater than 10^-6 GeV^-1. The LIPSS results show no evidence for scalar coupling in this region of parameter space.
Gravitational Field Shielding by Scalar Field and Type II Superconductors
Directory of Open Access Journals (Sweden)
Zhang B. J.
2013-01-01
Full Text Available The gravitational field shielding by scalar field and type II superconductors are theoret- ically investigated. In accord with the well-developed five-dimensional fully covariant Kaluza-Klein theory with a scalar field, which unifies the Einsteinian general relativity and Maxwellian electromagnetic theory, the scalar field cannot only polarize the space as shown previously, but also flatten the space as indicated recently. The polariza- tion of space decreases the electromagnetic field by increasing the equivalent vacuum permittivity constant, while the flattening of space decreases the gravitational field by decreasing the equivalent gravitational constant. In other words, the scalar field can be also employed to shield the gravitational field. A strong scalar field significantly shield the gravitational field by largely decreasing the equivalent gravitational constant. According to the theory of gravitational field shielding by scalar field, the weight loss experimentally detected for a sample near a rotating ceramic disk at very low tempera- ture can be explained as the shielding of the Earth gravitational field by the Ginzburg- Landau scalar field, which is produced by the type II superconductors. The significant shielding of gravitational field by scalar field produced by superconductors may lead to a new spaceflight technology in future.
Iso-scalar surfaces, mixing and reaction in turbulent flows
Dopazo, César; Martín, Jesús; Hierro, Juan
2006-08-01
Turbulent scalar mixing with chemical reaction is investigated in terms of the local geometrical features of the iso-scalar surfaces—'scalar field topologies'—, using Direct Numerical Simulation data. Two scalars with identical initial distribution, one inert and the other obeying a prescribed Arrhenius-like chemical reaction, evolve in homogeneous isotropic turbulence with a mesh size 256 3. The two local principal curvatures, k and k, of the iso-scalar surface at each point are straightforwardly obtained from the curvature tensor, n, whose elements are the spatial derivatives of the unit vector normal to the iso-surface. The scalar diffusive flux is decomposed into a 'flat-front' contribution plus a curvature induced molecular transport. Expressions for the normal propagating velocity relative to the fluid of iso-surfaces, of both the inert and the reactive scalar fields, are provided making use of the previous decomposition. The 'flat-front' and the curvature induced contributions to the diffusive fluxes, beside to the chemical reaction rate, are correlated with the principal curvatures. Results, including the joint statistics of the principal curvatures and their correlations with the scalar dissipation, are also presented. To cite this article: C. Dopazo et al., C. R. Mecanique 334 (2006).
Variational method for objective analysis of scalar variable and its ...
Indian Academy of Sciences (India)
In regard to variational optimization of meteoro- logical parameter a given measure of the 'distance' between the variational scalar analysis and the standard scalar analysis is minimized. The varia- tional analysed field must at the same time satisfy some constraint. The constraint is that the differ- ence between derivative of ...
Finsler metrics with constant (or scalar) flag curvature
Indian Academy of Sciences (India)
of new Finsler metrics of constant (or scalar) flag curvature and determine their scalar curvature. Keywords. ... For instance, Li, Chang and Mo related some Killing fields of Finsler metrics to the symmetry of very ...... [13] Shen Z, Differential Geometry of Spray and Finsler Spaces (Kluwer Academic Publish- ers) (2001) 258 ...
Small visible energy scalar top iterative discriminant analysis
Indian Academy of Sciences (India)
The search for scalar top quarks and the determination of their parameters in the framework of supersymmetric models are important aspects of the linear collider physics programme. The lightest neutralino with a small mass difference (∆m) to the scalar top quark is a candidate for dark matter in the Universe [1]. The.
Visualization of Scalar Adaptive Mesh Refinement Data
Energy Technology Data Exchange (ETDEWEB)
VACET; Weber, Gunther; Weber, Gunther H.; Beckner, Vince E.; Childs, Hank; Ligocki, Terry J.; Miller, Mark C.; Van Straalen, Brian; Bethel, E. Wes
2007-12-06
Adaptive Mesh Refinement (AMR) is a highly effective computation method for simulations that span a large range of spatiotemporal scales, such as astrophysical simulations, which must accommodate ranges from interstellar to sub-planetary. Most mainstream visualization tools still lack support for AMR grids as a first class data type and AMR code teams use custom built applications for AMR visualization. The Department of Energy's (DOE's) Science Discovery through Advanced Computing (SciDAC) Visualization and Analytics Center for Enabling Technologies (VACET) is currently working on extending VisIt, which is an open source visualization tool that accommodates AMR as a first-class data type. These efforts will bridge the gap between general-purpose visualization applications and highly specialized AMR visual analysis applications. Here, we give an overview of the state of the art in AMR scalar data visualization research.
Abelian scalar theory at large global charge
Energy Technology Data Exchange (ETDEWEB)
Loukas, Orestis [Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, University of Bern (Switzerland)
2017-09-15
We elaborate on Abelian complex scalar models, which are dictated by natural actions (all couplings are of order one), at fixed and large global U(1) charge in an arbitrary number of dimensions. The ground state vertical stroke v right angle is coherently constructed by the zero modes and the appearance of a centrifugal potential is quantum mechanically verified. Using the path integral formulation we systematically analyze the quantum fluctuations around vertical stroke v right angle in order to derive an effective action for the Goldstone mode, which becomes perturbatively meaningful when the charge is large. In this regime we explicitly show, by computing the first few loop corrections, that the whole construction is stable against quantum effects, in the sense that any higher derivative couplings to Goldstone's tree-level action are suppressed by appropriate powers of the large charge. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Observability of inert scalars at the LHC
Energy Technology Data Exchange (ETDEWEB)
Hashemi, Majid [Shiraz University, Physics Department, College of Sciences, Shiraz (Iran, Islamic Republic of); Najjari, Saereh [University of Warsaw, Faculty of Physics, Warsaw (Poland)
2017-09-15
In this work we investigate the observability of inert doublet model scalars at the LHC operating at the center of mass energy of 14 TeV. The signal production process is pp → AH{sup ±} → ZHW{sup ±}H leading to two different final states of l{sup +}l{sup -}HjjH and l{sup +}l{sup -}Hl{sup ±}νH based on the hadronic and leptonic decay channels of the W boson. All the relevant background processes are considered and an event selection is designed to distinguish the signal from the large Standard Model background. We found that signals of the selected search channels are well observable at the LHC with an integrated luminosity of 300 fb{sup -1}. (orig.)
LHC constraints on color octet scalars
Hayreter, Alper; Valencia, German
2017-08-01
We extract constraints on the parameter space of the Manohar and Wise model by comparing the cross sections for dijet, top-pair, dijet-pair, t t ¯t t ¯ and b b ¯b b ¯ productions at the LHC with the strongest available experimental limits from ATLAS or CMS at 8 or 13 TeV. Overall we find mass limits around 1 TeV in the most sensitive regions of parameter space, and lower elsewhere. This is at odds with generic limits for color octet scalars often quoted in the literature where much larger production cross sections are assumed. The constraints that can be placed on coupling constants are typically weaker than those from existing theoretical considerations, with the exception of the parameter ηD.
The BEH mechanism and its scalar bosons
CERN. Geneva
2014-01-01
In the beginning of the 1960’s, the long range interactions within our universe were well understood from the laws of classical general relativity, Einstein’s generalisation of Newtonian gravity, and of quantum electrodynamics, the quantum version of Maxwell’s electromagnetic theory. But there was no hints of how to formulate consistent fundamental theories of short range interactions. A solution to this problem was proposed by Robert Brout and me, and independently by Peter Higgs. I shall explain our motivations for constructing this BEH mechanism and discuss its content. I will comment on how the magnificent ATLAS and CMS discovery at CERN of the scalar boson predicted by the mechanism confirms its validity and may have implications on structures at yet unexplored energies.
Scalar dark matter with type II seesaw
Directory of Open Access Journals (Sweden)
Arnab Dasgupta
2014-12-01
Full Text Available We study the possibility of generating tiny neutrino mass through a combination of type I and type II seesaw mechanism within the framework of an abelian extension of standard model. The model also provides a naturally stable dark matter candidate in terms of the lightest neutral component of a scalar doublet. We compute the relic abundance of such a dark matter candidate and also point out how the strength of type II seesaw term can affect the relic abundance of dark matter. Such a model which connects neutrino mass and dark matter abundance has the potential of being verified or ruled out in the ongoing neutrino, dark matter, as well as accelerator experiments.
Anderson, David; Yunes, Nicolás
2017-09-01
Scalar-tensor theories of gravity modify general relativity by introducing a scalar field that couples nonminimally to the metric tensor, while satisfying the weak-equivalence principle. These theories are interesting because they have the potential to simultaneously suppress modifications to Einstein's theory on Solar System scales, while introducing large deviations in the strong field of neutron stars. Scalar-tensor theories can be classified through the choice of conformal factor, a scalar that regulates the coupling between matter and the metric in the Einstein frame. The class defined by a Gaussian conformal factor with a negative exponent has been studied the most because it leads to spontaneous scalarization (i.e. the sudden activation of the scalar field in neutron stars), which consequently leads to large deviations from general relativity in the strong field. This class, however, has recently been shown to be in conflict with Solar System observations when accounting for the cosmological evolution of the scalar field. We here study whether this remains the case when the exponent of the conformal factor is positive, as well as in another class of theories defined by a hyperbolic conformal factor. We find that in both of these scalar-tensor theories, Solar System tests are passed only in a very small subset of coupling parameter space, for a large set of initial conditions compatible with big bang nucleosynthesis. However, while we find that it is possible for neutron stars to scalarize, one must carefully select the coupling parameter to do so, and even then, the scalar charge is typically 2 orders of magnitude smaller than in the negative-exponent case. Our study suggests that future work on scalar-tensor gravity, for example in the context of tests of general relativity with gravitational waves from neutron star binaries, should be carried out within the positive coupling parameter class.
Design & simulation of in-plane MEMS Lorentz force magnetometer
Jyoti, Aditi, Tripathi, C. C.; Gopal, Ram
2016-03-01
This report presents the design and simulation of a MEMS based In-plane Lorentz Force Magnetometer (I-LFM), simulated for 8 um UV-LIGA technology using FEM tool of COMSOL Multiphysics 4.3b. Designed I-LFM was simulated in the magnetic field range varied from 1 μJT to 100μJT. The proposed structure composed of a comb drive actuator, configured such that the fingers overlap with each other to generate capacitive coupling for its actuation. The magnetic field can be detected in Z-axis by this comb drive structure. The device was excited by supplying the sinusoidal current with the frequency equivalent to resonance frequency of the device at its first mode i.e. 12.047 kHz. In order to achieve the maximum mechanical output, the device was operated at the resonant frequency. Simulations based results shows a good linearity in the magnetic field range of 1 μJT to 100 μJT with a high quality factor of 130.
Ground pulsation magnetometer observations conjugated with relativistic electron precipitation
Yahnin, A. G.; Yahnina, T. A.; Raita, T.; Manninen, J.
2017-09-01
In this report, we investigate the role of electromagnetic ion cyclotron (EMIC) waves in production of relativistic electron precipitation (REP). Over a thousand REP events were detected from four NOAA Polar-orbiting Operational Environmental Satellites in July-December 2005. Of these, a total of 112 events were conjugated with a ground-based network of six Finnish induction coil magnetometers and one in Lovozero observatory at Kola Peninsula, Russia. The observation of geomagnetic pulsations during the conjugated events showed that about one third of them were accompanied by pulsations in the Pc1 range, which are the signature of EMIC waves. In fact, the sources of some of these EMIC waves were well outside the location of the REP event. This means that in such cases the REP events were not originated from scattering by EMIC waves. Finally, it is concluded that for this limited set of conjugated events only a quarter might be related to scattering by EMIC waves. The majority of the events are not correlated with EMIC wave signatures in ground-based observations; they were associated with either no pulsations or noise-like pulsations PiB and PiC.
Ultra-sensitive Magnetic Microscopy with an Optically Pumped Magnetometer
Kim, Young Jin; Savukov, Igor
2016-04-01
Optically pumped magnetometers (OPMs) based on lasers and alkali-metal vapor cells are currently the most sensitive non-cryogenic magnetic field sensors. Many applications in neuroscience and other fields require high-resolution, high-sensitivity magnetic microscopic measurements. In order to meet this demand we combined a cm-size spin-exchange relaxation-free (SERF) OPM and flux guides (FGs) to realize an ultra-sensitive FG-OPM magnetic microscope. The FGs serve to transmit the target magnetic flux to the OPM thus improving both the resolution and sensitivity to small magnetic objects. We investigated the performance of the FG-OPM device using experimental and numerical methods, and demonstrated that an optimized device can achieve a unique combination of high resolution (80 μm) and high sensitivity (8.1 pT/). In addition, we also performed numerical calculations of the magnetic field distribution in the FGs to estimate the magnetic noise originating from the domain fluctuations in the material of the FGs. We anticipate many applications of the FG-OPM device such as the detection of micro-biological magnetic fields; the detection of magnetic nano-particles; and non-destructive testing. From our theoretical estimate, an FG-OPM could detect the magnetic field of a single neuron, which would be an important milestone in neuroscience.
Unique Fock quantization of scalar cosmological perturbations
Fernández-Méndez, Mikel; Mena Marugán, Guillermo A.; Olmedo, Javier; Velhinho, José M.
2012-05-01
We investigate the ambiguities in the Fock quantization of the scalar perturbations of a Friedmann-Lemaître-Robertson-Walker model with a massive scalar field as matter content. We consider the case of compact spatial sections (thus avoiding infrared divergences), with the topology of a three-sphere. After expanding the perturbations in series of eigenfunctions of the Laplace-Beltrami operator, the Hamiltonian of the system is written up to quadratic order in them. We fix the gauge of the local degrees of freedom in two different ways, reaching in both cases the same qualitative results. A canonical transformation, which includes the scaling of the matter-field perturbations by the scale factor of the geometry, is performed in order to arrive at a convenient formulation of the system. We then study the quantization of these perturbations in the classical background determined by the homogeneous variables. Based on previous work, we introduce a Fock representation for the perturbations in which: (a) the complex structure is invariant under the isometries of the spatial sections and (b) the field dynamics is implemented as a unitary operator. These two properties select not only a unique unitary equivalence class of representations, but also a preferred field description, picking up a canonical pair of field variables among all those that can be obtained by means of a time-dependent scaling of the matter field (completed into a linear canonical transformation). Finally, we present an equivalent quantization constructed in terms of gauge-invariant quantities. We prove that this quantization can be attained by a mode-by-mode time-dependent linear canonical transformation which admits a unitary implementation, so that it is also uniquely determined.
Energy Technology Data Exchange (ETDEWEB)
Safronova, M. S. [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Mitroy, J. [School of Engineering, Charles Darwin University, Darwin NT 0909 (Australia); Clark, Charles W. [Joint Quantum Institute, National Institute of Standards and Technology and the University of Maryland, Gaithersburg, Maryland 20899-8410 (United States); Kozlov, M. G. [Petersburg Nuclear Physics Institute, Gatchina 188300 (Russian Federation)
2015-01-22
The atomic dipole polarizability governs the first-order response of an atom to an applied electric field. Atomic polarization phenomena impinge upon a number of areas and processes in physics and have been the subject of considerable interest and heightened importance in recent years. In this paper, we will summarize some of the recent applications of atomic polarizability studies. A summary of results for polarizabilities of noble gases, monovalent, and divalent atoms is given. The development of the CI+all-order method that combines configuration interaction and linearized coupled-cluster approaches is discussed.
Foot, Christopher J
2007-01-01
This text will thoroughly update the existing literature on atomic physics. Intended to accompany an advanced undergraduate course in atomic physics, the book will lead the students up to the latest advances and the applications to Bose-Einstein Condensation of atoms, matter-wave inter-ferometry and quantum computing with trapped ions. The elementary atomic physics covered in the early chapters should be accessible to undergraduates when they are first introduced to the subject. To complement. the usual quantum mechanical treatment of atomic structure the book strongly emphasizes the experimen
Co-seismic signatures in magnetometer, geophone, and infrasound data during the Meinong Earthquake
Directory of Open Access Journals (Sweden)
Jann-Yenq Liu
2017-01-01
Full Text Available This paper utilizes 10 stations of co-located seismometer, QuakeFinder/infrasound to observe co-seismic signatures triggered by the 6 February 2016 M 6.6 Meinong Earthquake. Each QuakeFinder system consists of a 3-axes induction magnetometer, an air conductivity sensor, a geophone, and temperature/relative humidity sensors. There are no obvious charges in the positive/negative ions, the temperature, and the humidity, while the magnetometer, the geophone, and infrasound data detect clear co-seismic signatures, similar to seismic waves recorded by seismometers. The magnetometers register high-frequency pulsations, like seismic waves, and superimpose with low-frequency variations, which could be caused by the magnetometer shaking/tilting and/or the underground water level change, respectively, upon the arrival of seismic waves. The spectrum centering around 2.0 Hz of the co-seismic geophone fluctuations is similar to that of the seismic waves. However, the energy of co-seismic geophone fluctuations (also magnetometer pulsations yields an exponential decay to the distance of a station to the epicenter, while the energy of the seismic waves is inversely proportional to the square of the distance. This suggests that the mechanisms for detecting seismic waves of the QuakeFinder system and seismometers are different. In general, the geophone and magnetometer/infrasound system are useful to record high- and low-frequency seismic waves, respectively.
A portable Hall magnetometer probe for characterization of magnetic iron oxide nanoparticles
Energy Technology Data Exchange (ETDEWEB)
Araujo, Jefferson F.D.F.; Costa, Mateus C.; Louro, Sonia R.W.; Bruno, Antonio C., E-mail: acbruno@puc-rio.br
2017-03-15
We have built a portable Hall magnetometer probe, for measuring magnetic properties of iron oxide nanoparticles, that can be used for bulk materials and liquid samples as well. The magnetometer probe consists of four voltage-programmable commercial Hall sensors and a thin acrylic plate for positioning the sensors. In order to operate, it needs to be attached to a pole of an electromagnet and connected to an AD converter and a computer. It acquires a complete magnetization curve in a couple of minutes and has a magnetic moment sensitivity of 3.5×10{sup −7} Am{sup 2}. We tested its performance with magnetic nanoparticles containing an iron oxide core and having coating layers with different sizes. The magnetization results obtained were compared with measurements performed on commercial stand-alone magnetometers, and exhibited errors of about ±0.2 Am{sup 2}/kg (i.e 0.4%) at saturation and below 0.5 Am{sup 2}/kg (i.e. 10%) at remanence. - Highlights: • A low-cost portable Hall magnetometer probe has been built. • The Hall magnetometer probe can be attached to any electromagnet. • The Hall probe was calibrated and successfully compared to industry standard magnetometers. • The Hall probe was able to measure iron oxide nanoparticles with different coatings.
Quantitative magnetospheric models derived from spacecraft magnetometer data
Mead, G. D.; Fairfield, D. H.
1973-01-01
Quantitative models of the external magnetospheric field were derived by making least-squares fits to magnetic field measurements from four IMP satellites. The data were fit to a power series expansion in the solar magnetic coordinates and the solar wind-dipole tilt angle, and thus the models contain the effects of seasonal north-south asymmetries. The expansions are divergence-free, but unlike the usual scalar potential expansions, the models contain a nonzero curl representing currents distributed within the magnetosphere. Characteristics of four models are presented, representing different degrees of magnetic disturbance as determined by the range of Kp values. The latitude at the earth separating open polar cap field lines from field lines closing on the dayside is about 5 deg lower than that determined by previous theoretically-derived models. At times of high Kp, additional high latitude field lines are drawn back into the tail.
DEFF Research Database (Denmark)
Krüger, Peter; Hofferberth, S.; Haller, E.
2005-01-01
Miniaturized potentials near the surface of atom chips can be used as flexible and versatile tools for the manipulation of ultracold atoms on a microscale. The full scope of possibilities is only accessible if atom-surface distances can be reduced to microns. We discuss experiments in this regime...
Cha, Chong M.; de Bruyn Kops, Stephen M.; Mortensen, Mikael
2006-06-01
The double scalar mixing layer (DSML) is a canonical problem for studying the mixing of multiple streams and, with reaction, combustion of the partially premixed type. In a DSML, a third stream consisting of a premixture of the reactants is introduced in between the pure fuel and air streams of the classic twin-feed or binary mixing problem. The well-known presumed probability density function (PDF), such as the β-PDF, can adequately model passive scalar mixing for the binary mixing problem on which state-of-the-art turbulent combustion models such as conditional moment closure and flamelet approaches rely. However, the β-PDF model, now a standard in CFD simulation, cannot describe turbulent mixing involving multiple streams; e.g., the asymmetric three-stream mixing characterizing the DSML. In this paper, direct numerical simulations of the DSML are performed to make available a high-fidelity database for developing more general, fine-scale mixing models required to compute turbulent combustion problems of practical engineering interest, which usually involve mixing between multiple streams. In this first part of two investigations, nonreacting numerical experiments are presented with emphasis on the nontrivial distributions of the passive scalar and its dissipation rate. Mapping closure modeling is applied to describe the PDFs and conditional dissipation rates of a single mixture fraction.
Ignat'ev, Yu G
2013-01-01
On the basis of Hamilton a formalism the dynamic equations of movement scalar charged particles in a classical scalar field are formulated. Unlike earlier published works of the author the model with zero own weight of particles is considered. Linear integrals of movement are found and ambiguity of communication between kinematic speed and an impulse of particles is specified.
Joint Scalar versus Joint Velocity-Scalar PDF Simulations of Bluff-Body Stabilized Flames with REDIM
Merci, B.; Naud, B.; Roekaerts, D.; Maas, U.
2008-01-01
Two transported PDF strategies, joint velocity-scalar PDF (JVSPDF) and joint scalar PDF (JSPDF), are investigated for bluff-body stabilized jet-type turbulent diffusion flames with a variable degree of turbulence–chemistry interaction. Chemistry is modeled by means of the novel reaction-diffusion
Development of Autonomous Magnetometer Rotorcraft For Wide Area Assessment
Energy Technology Data Exchange (ETDEWEB)
Mark D. McKay; Matthew O. Anderson
2011-08-01
Large areas across the United States and internationally are potentially contaminated with unexploded ordinance (UXO), with some ranges encompassing tens to hundreds of thousands of acres. Technologies are needed which will allow for cost effective wide area scanning with (1) near 100% coverage and (2) near 100% detection of subsurface ordnance or features indicative of subsurface ordnance. The current approach to wide area assessment is a multi-level one, in which medium - altitude fixed wing optical imaging is used for an initial site assessment. This assessment is followed with low altitude manned helicopter based magnetometry. Subsequent to this wide area assessment targeted surface investigations are performed using either towed geophysical sensor arrays or man portable sensors. In order to be an effective tool for small UXO detection, the sensing altitude for magnetic site investigations needs to be on the order of 1 to 3 meters. These altitude requirements mean that manned helicopter surveys will generally only be feasible in large, open and relatively flat terrains. While such surveys are effective in mapping large areas relatively fast there are substantial mobilization/demobilization, staffing and equipment costs associated with these surveys, resulting in costs of approximately $100-$150/acre. In addition, due to the low altitude there are substantial risks to pilots and equipment. Surface towed arrays provide highresolution maps but have other limitations, e.g. in their ability to navigate rough terrain effectively. Thus there is a need for other systems, which can be used for effective data collection. An Unmanned Aerial Vehicle (UAV) magnetometer platform is an obvious alternative. The motivation behind such a system is that it reduces risk to operators, is lower in initial and Operational and Maintenance (O&M) costs (and can thus potentially be applied to smaller sites) and has the potential of being more effective in terms of detection and possibly
Probing dark energy with atom interferometry
Energy Technology Data Exchange (ETDEWEB)
Burrage, Clare; Copeland, Edmund J. [School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD (United Kingdom); Hinds, E.A., E-mail: Clare.Burrage@nottingham.ac.uk, E-mail: Edmund.Copeland@nottingham.ac.uk, E-mail: Ed.Hinds@imperial.ac.uk [Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2AZ (United Kingdom)
2015-03-01
Theories of dark energy require a screening mechanism to explain why the associated scalar fields do not mediate observable long range fifth forces. The archetype of this is the chameleon field. Here we show that individual atoms are too small to screen the chameleon field inside a large high-vacuum chamber, and therefore can detect the field with high sensitivity. We derive new limits on the chameleon parameters from existing experiments, and show that most of the remaining chameleon parameter space is readily accessible using atom interferometry.
Atomic Reference Data for Electronic Structure Calculations
Kotochigova, S; Shirley, E L
We have generated data for atomic electronic structure calculations, to provide a standard reference for results of specified accuracy under commonly used approximations. Results are presented here for total energies and orbital energy eigenvalues for all atoms from H to U, at microHartree accuracy in the total energy, as computed in the local-density approximation (LDA) the local-spin-density approximation (LSD); the relativistic local-density approximation (RLDA); and scalar-relativistic local-density approximation (ScRLDA).
Electrically charged Kerr black holes with scalar hair
Delgado, Jorge F M; Radu, Eugen; Runarsson, Helgi
2016-01-01
We construct electrically charged Kerr black holes (BHs) with scalar hair. Firstly, we take an uncharged scalar field, interacting with the electromagnetic field only indirectly, via the background metric. The corresponding family of solutions, dubbed Kerr-Newman BHs with ungauged scalar hair, reduces to (a sub-family of) Kerr-Newman BHs in the limit of vanishing scalar hair and to uncharged rotating boson stars in the limit of vanishing horizon. It adds one extra parameter to the uncharged solutions: the total electric charge. This leading electromagnetic multipole moment is unaffected by the scalar hair and can be computed by using Gauss's law on any closed 2-surface surrounding (a spatial section of) the event horizon. By contrast, the first sub-leading electromagnetic multipole -- the magnetic dipole moment --, gets suppressed by the scalar hair, such that the gyromagnetic ratio is always smaller than the Kerr-Newman value ($g=2$). Secondly, we consider a gauged scalar field and obtain a family of Kerr-Ne...
Light-shift measurement and suppression in atomic spin gyroscope.
Fang, Jiancheng; Wan, Shuangai; Chen, Yao; Li, Rujie
2012-11-01
We present a method to determine and suppress the light shift in an atomic spin gyroscope. This method doesn't require additional drive source or frequency modulation, and it is based on the dynamics of an atomic spin gyroscope to determine a clean curve as a function of the frequency of the pump beam that predicts the zero light shift. We experimentally validate the method in a Cs-(129)Xe atomic spin gyroscope and verify the results through numerical simulations. This method can also be applied to an atomic spin magnetometer based on the spin-exchange relaxation-free exchange that experiences light shift. The method is useful for atomic spin devices because it can improve long-term performance and reduce the influence of the laser.
Longitudinal W boson scattering in a light scalar top scenario
Ishiwata, Koji; Yonekura, Yuki
2017-07-01
Scalar tops in the supersymmetric model affect the potential of the standard model-like Higgs at the quantum level. In light of the equivalence theorem, the deviation of the potential from the standard model can be traced by longitudinal gauge bosons. In this work, high-energy longitudinal W boson scattering is studied in a TeV-scale scalar top scenario. O (1 - 10 %) deviation from the standard model prediction in the differential cross section is found, depending on whether the observed Higgs mass is explained only by scalar tops or by additional contributions at a higher scale.
Brief History of Ultra-light Scalar Dark Matter Models
Lee Jae-Weon
2018-01-01
This is a review on the brief history of the scalar field dark matter model also known as fuzzy dark matter, BEC dark matter, wave dark matter, or ultra-light axion. In this model ultra-light scalar dark matter particles with mass m = O(10-22)eV condense in a single Bose-Einstein condensate state and behave collectively like a classical wave. Galactic dark matter halos can be described as a self-gravitating coherent scalar field configuration called boson stars. At the scale larger than ga...
Scalar-Tensor Black Holes Embedded in an Expanding Universe
Tretyakova, Daria; Latosh, Boris
2018-02-01
In this review we focus our attention on scalar-tensor gravity models and their empirical verification in terms of black hole and wormhole physics. We focus on a black hole, embedded in an expanding universe, describing both cosmological and astrophysical scales. We show that in scalar-tensor gravity it is quite common that the local geometry is isolated from the cosmological expansion, so that it does not backreact on the black hole metric. We try to extract common features of scalar-tensor black holes in an expanding universe and point out the gaps that must be filled.
Effect of the chameleon scalar field on brane cosmological evolution
Directory of Open Access Journals (Sweden)
Y. Bisabr
2017-11-01
Full Text Available We have investigated a brane world model in which the gravitational field in the bulk is described both by a metric tensor and a minimally coupled scalar field. This scalar field is taken to be a chameleon with an appropriate potential function. The scalar field interacts with matter and there is an energy transfer between the two components. We find a late-time asymptotic solution which exhibits late-time accelerating expansion. We also show that the Universe recently crosses the phantom barrier without recourse to any exotic matter. We provide some thermodynamic arguments which constrain both the direction of energy transfer and dynamics of the extra dimension.
Effect of the chameleon scalar field on brane cosmological evolution
Bisabr, Y.; Ahmadi, F.
2017-11-01
We have investigated a brane world model in which the gravitational field in the bulk is described both by a metric tensor and a minimally coupled scalar field. This scalar field is taken to be a chameleon with an appropriate potential function. The scalar field interacts with matter and there is an energy transfer between the two components. We find a late-time asymptotic solution which exhibits late-time accelerating expansion. We also show that the Universe recently crosses the phantom barrier without recourse to any exotic matter. We provide some thermodynamic arguments which constrain both the direction of energy transfer and dynamics of the extra dimension.
Scalar-Tensor Black Holes Embedded in an Expanding Universe
Directory of Open Access Journals (Sweden)
Daria Tretyakova
2018-02-01
Full Text Available In this review, we focus our attention on scalar-tensor gravity models and their empirical verification in terms of black hole and wormhole physics. We focus on black holes, embedded in an expanding universe, describing both cosmological and astrophysical scales. We show that in scalar-tensor gravity it is quite common that the local geometry is isolated from the cosmological expansion, so that it does not backreact on the black hole metric. We try to extract common features of scalar-tensor black holes in an expanding universe and point out the issues that are not fully investigated.
Charged scalar perturbations around Garfinkle–Horowitz–Strominger black holes
Directory of Open Access Journals (Sweden)
Cheng-Yong Zhang
2015-10-01
Full Text Available We examine the stability of the Garfinkle–Horowitz–Strominger (GHS black hole under charged scalar perturbations. Employing the appropriate numerical methods, we show that the GHS black hole is always stable against charged scalar perturbations. This is different from the results obtained in the de Sitter and anti-de Sitter black holes. Furthermore, we argue that in the GHS black hole background there is no amplification of the incident charged scalar wave to cause the superradiance, so that the superradiant instability cannot exist in this spacetime.
Scalarization of neutron stars with realistic equations of state
Altaha Motahar, Zahra; Blázquez-Salcedo, Jose Luis; Kleihaus, Burkhard; Kunz, Jutta
2017-09-01
We consider the effect of scalarization on static and slowly rotating neutron stars for a wide variety of realistic equations of state, including pure nuclear matter, nuclear matter with hyperons, hybrid nuclear and quark matter, and pure quark matter. We analyze the onset of scalarization, presenting a universal relation for the critical coupling parameter versus compactness. We find that the onset and the magnitude of the scalarization are strongly correlated with the value of the gravitational potential (the metric component gt t) at the center of the star. We also consider the moment-of-inertia-compactness relations and confirm universality for the nuclear matter, hyperon and hybrid equations of state.
On the transverse Scalar Curvature of a Compact Sasaki Manifold
Directory of Open Access Journals (Sweden)
He Weiyong
2014-09-01
Full Text Available We show that the standard picture regarding the notion of stability of constant scalar curvature metrics in Kähler geometry described by S.K. Donaldson [10, 11], which involves the geometry of infinitedimensional groups and spaces, can be applied to the constant scalar curvature metrics in Sasaki geometry with only few modification. We prove that the space of Sasaki metrics is an infinite dimensional symmetric space and that the transverse scalar curvature of a Sasaki metric is a moment map of the strict contactomophism group
Brief History of Ultra-light Scalar Dark Matter Models
Lee Jae-Weon
2018-01-01
This is a review on the brief history of the scalar field dark matter model also known as fuzzy dark matter, BEC dark matter, wave dark matter, or ultra-light axion. In this model ultra-light scalar dark matter particles with mass $m = O(10^{-22})eV$ condense in a single Bose-Einstein condensate state and behave collectively like a classical wave. Galactic dark matter halos can be described as a self-gravitating coherent scalar field configuration called boson stars. At the scale larger than ...
Brief History of Ultra-light Scalar Dark Matter Models
Lee, Jae-Weon
2017-01-01
This is an ongoing review on the brief history of the scalar field dark matter model also known as fuzzy dark matter, BEC dark matter, wave dark matter, or ultra-light axion. In this model ultra-light scalar dark matter particles with mass $m = O(10^{-22})eV$ condense in a single Bose-Einstein condensate state and behave collectively like a classical wave. Galactic dark matter halos can be described as a self-gravitating coherent scalar field configuration called boson stars. At the scale lar...
Transverse relaxation of scalar-coupled protons.
Segawa, Takuya F; Baishya, Bikash; Bodenhausen, Geoffrey
2010-10-25
In a preliminary communication (B. Baishya, T. F. Segawa, G. Bodenhausen, J. Am. Chem. Soc. 2009, 131, 17538-17539), we recently demonstrated that it is possible to obtain clean echo decays of protons in biomolecules despite the presence of homonuclear scalar couplings. These unmodulated decays allow one to determine apparent transverse relaxation rates R(2) (app) of individual protons. Herein, we report the observation of R(2) (app) for three methyl protons, four amide H(N) protons, and all 11 backbone H(α) protons in cyclosporin A. If the proton resonances overlap, their R(2) (app) rates can be measured by transferring their magnetization to neighboring (13)C nuclei, which are less prone to overlap. The R(2) (app) rates of protons attached to (13)C are faster than those attached to (12)C because of (13)C-(1)H dipolar interactions. The differences of these rates allow the determination of local correlation functions. Backbone H(N) and H(α) protons that have fast decay rates R(2) (app) also feature fast longitudinal relaxation rates R(1) and intense NOESY cross peaks that are typical of crowded environments. Variations of R(2) (app) rates of backbone H(α) protons in similar amino acids reflect differences in local environments.
Searches for high mass BSM scalars
Nam, Kyungwook
2017-01-01
Searches for BSM particles using the 126 GeV Higgs boson have been carried out with the CMS detector at LHC, based on pp collision data collected at centre-of-mass energies of 7, 8, and 13 TeV. The talk presents the latest results and gives a brief review of earlier results. A search for heavy resonances decaying to Zgamma is presented. This search is based on the data collected with the CMS detector at 13 TeV. The search strategy is to look for an excess above the non-resonant Standard Model background in the Zgamma invariant mass spectrum. The background is extracted directly from data and compared with the signal expected to be produced by hypothetical scalar resonances. While the HH production within the Standard Model is very small and essentially out of the experimental reach within the LHC Run II, several theories foresee an enhancement that can be already probed with the available data. The latest searches for resonant and non-resonant Higgs pair production, made using 13 TeV pp collisions data recor...
On the Scalar Manifold of Exceptional Supergravity
Cacciatori, Sergio L; Marrani, Alessio
2012-01-01
We construct two parametrizations of the non compact exceptional Lie group G=E7(-25), based on a fibration which has the maximal compact subgroup K=(E6 x U(1))/Z_3 as a fiber. It is well known that G plays an important role in the N=2 d=4 magic exceptional supergravity, where it describes the U-duality of the theory and where the symmetric space M=G/K gives the vector multiplets' scalar manifold. First, by making use of the exponential map, we compute a realization of G/K, that is based on the E6 invariant d-tensor, and hence exhibits the maximal possible manifest [(E6 x U(1))/Z_3]-covariance. This provides a basis for the corresponding supergravity theory, which is the analogue of the Calabi-Vesentini coordinates. Then we study the Iwasawa decomposition. Its main feature is that it is SO(8)-covariant and therefore it highlights the role of triality. Along the way we analyze the relevant chain of maximal embeddings which leads to SO(8). It is worth noticing that being based on the properties of a "mixed" Freu...
Born, Max
1969-01-01
The Nobel Laureate's brilliant exposition of the kinetic theory of gases, elementary particles, the nuclear atom, wave-corpuscles, atomic structure and spectral lines, electron spin and Pauli's principle, quantum statistics, molecular structure and nuclear physics. Over 40 appendices, a bibliography, numerous figures and graphs.
Indian Academy of Sciences (India)
http://www.ias.ac.in/article/fulltext/reso/015/10/0905-0925. Keywords. Atomic theory; Avogadro's hypothesis; atomic weights; periodic table; valence; molecular weights; molecular formula; isomerism. Author Affiliations. S Ramasesha1. Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, ...
Scalar quark searches in $e^+ e^-$ collisions at $\\sqrt{s}$ = 181-184 GeV
Barate, R; Décamp, D; Ghez, P; Goy, C; Jézéquel, S; Lees, J P; Lucotte, A; Martin, F; Merle, E; Minard, M N; Nief, J Y; Pietrzyk, B; Alemany, R; Boix, G; Casado, M P; Chmeissani, M; Crespo, J M; Delfino, M C; Fernández, E; Fernández-Bosman, M; Garrido, L; Graugès-Pous, E; Juste, A; Martínez, M; Merino, G; Miquel, R; Mir, L M; Morawitz, P; Park, I C; Pascual, A; Riu, I; Sánchez, F; Colaleo, A; Creanza, D; De Palma, M; Gelao, G; Iaselli, Giuseppe; Maggi, G; Maggi, M; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Becker, U; Bright-Thomas, P G; Casper, David William; Cattaneo, M; Ciulli, V; Dissertori, G; Drevermann, H; Forty, Roger W; Frank, M; Gianotti, F; Hagelberg, R; Hansen, J B; Harvey, J; Janot, P; Jost, B; Lehraus, Ivan; Maley, P; Mato, P; Minten, Adolf G; Moneta, L; Qi, N; Pacheco, A; Ranjard, F; Rolandi, Luigi; Rousseau, D; Schlatter, W D; Schmitt, M; Schneider, O; Tejessy, W; Teubert, F; Tomalin, I R; Vreeswijk, M; Wachsmuth, H W; Ajaltouni, Ziad J; Badaud, F; Chazelle, G; Deschamps, O; Falvard, A; Ferdi, C; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rosnet, P; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Rensch, B; Wäänänen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, Errietta; Vayaki, Anna; Blondel, A; Brient, J C; Machefert, F P; Rougé, A; Rumpf, M; Tanaka, R; Valassi, Andrea; Videau, H L; Focardi, E; Parrini, G; Zachariadou, K; Cavanaugh, R J; Corden, M; Georgiopoulos, C H; Hühn, T; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Cerutti, F; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Chalmers, M; Curtis, L; Halley, A W; Lynch, J G; Negus, P; O'Shea, V; Raine, C; Scarr, J M; Smith, K; Teixeira-Dias, P; Thompson, A S; Thomson, E; Ward, J J; Buchmüller, O L; Dhamotharan, S; Geweniger, C; Graefe, G; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Sommer, J; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Girone, M; Goodsir, S M; Martin, E B; Marinelli, N; Moutoussi, A; Nash, J; Sedgbeer, J K; Spagnolo, P; Williams, M D; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Bowdery, C K; Buck, P G; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Jones, R W L; Robertson, N A; Williams, M I; Giehl, I; Hoffmann, C; Jakobs, K; Kleinknecht, K; Kröcker, M; Nürnberger, H A; Quast, G; Renk, B; Rohne, E; Sander, H G; Van Gemmeren, P; Zeitnitz, C; Ziegler, T; Aubert, Jean-Jacques; Benchouk, C; Bonissent, A; Bujosa, G; Carr, J; Coyle, P; Ealet, A; Fouchez, D; Leroy, O; Motsch, F; Payre, P; Talby, M; Sadouki, A; Thulasidas, M; Tilquin, A; Trabelsi, K; Aleppo, M; Antonelli, M; Ragusa, F; Berlich, R; Büscher, V; Cowan, G D; Dietl, H; Ganis, G; Lütjens, G; Mannert, C; Männer, W; Moser, H G; Schael, S; Settles, Ronald; Seywerd, H C J; Stenzel, H; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Chen, S; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Höcker, A; Jacholkowska, A; Kado, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Serin, L; Tournefier, E; Veillet, J J; Videau, I; Zerwas, D; Azzurri, P; Bagliesi, G; Bettarini, S; Boccali, T; Bozzi, C; Calderini, G; Dell'Orso, R; Fantechi, R; Ferrante, I; Giassi, A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, Fabrizio; Rizzo, G; Sanguinetti, G; Sciabà, A; Sguazzoni, G; Tenchini, Roberto; Vannini, C; Venturi, A; Verdini, P G; Blair, G A; Bryant, L M; Chambers, J T; Coles, J; Green, M G; Medcalf, T; Perrodo, P; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Norton, P R; Thompson, J C; Wright, A E; Bloch-Devaux, B; Colas, P; Fabbro, B; Faïf, G; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Przysiezniak, H; Rander, J; Renardy, J F; Rosowsky, A; Roussarie, A; Trabelsi, A; Vallage, B; Black, S N; Dann, J H; Kim, H Y; Konstantinidis, N P; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Cartwright, S L; Combley, F; Kelly, M S; Lehto, M H; Thompson, L F; Affholderbach, K; Böhrer, A; Brandt, S; Foss, J; Grupen, Claus; Smolik, L; Stephan, F; Giannini, G; Gobbo, B; Musolino, G; Pütz, J; Rothberg, J E; Wasserbaech, S R; Williams, R W; Armstrong, S R; Betteridge, A P; Charles, E; Elmer, P; Ferguson, D P S; Gao, Y; González, S; Greening, T C; Hayes, O J; Hu, H; Jin, S; McNamara, P A; Nachtman, J M; Nielsen, J; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, J; Wu Sau Lan; Wu, X; Zobernig, G
1998-01-01
Searches for scalar top, scalar bottom and degenerate scalar quarks have been performed with data collected with the ALEPH detector at LEP. The data sample consists of 57~$\\mathrm{pb}^{-1}$ taken at $\\rts$ = 181--184~GeV. No evidence for scalar top, scalar bottom or degenerate scalar quarks was found in the channels $\\stop \\rightarrow \\mathrm{c}\
A quantitative magnetospheric model derived from spacecraft magnetometer data
Mead, G. D.; Fairfield, D. H.
1975-01-01
The model is derived by making least squares fits to magnetic field measurements from four Imp satellites. It includes four sets of coefficients, representing different degrees of magnetic disturbance as determined by the range of Kp values. The data are fit to a power series expansion in the solar magnetic coordinates and the solar wind-dipole tilt angle, and thus the effects of seasonal north-south asymmetries are contained. The expansion is divergence-free, but unlike the usual scalar potential expansion, the model contains a nonzero curl representing currents distributed within the magnetosphere. The latitude at the earth separating open polar cap field lines from field lines closing on the day side is about 5 deg lower than that determined by previous theoretically derived models. At times of high Kp, additional high-latitude field lines extend back into the tail. Near solstice, the separation latitude can be as low as 75 deg in the winter hemisphere. The average northward component of the external field is much smaller than that predicted by theoretical models; this finding indicates the important effects of distributed currents in the magnetosphere.
A dumbbell-shaped hybrid magnetometer operating in DC-10 kHz
Shi, Hongyu; Wang, Yanzhang; Chen, Siyu; Lin, Jun
2017-12-01
This study is motivated by the need to design a hybrid magnetometer operating in a wide-frequency band from DC to 10 kHz. To achieve this objective, a residence times difference fluxgate magnetometer (RTDFM) and an induction magnetometer (IM) have been integrated into a compact form. The hybrid magnetometer has a dumbbell-shaped structure in which the RTDFM transducer is partially inserted into the tube cores of the IM. Thus, the sensitivity of the RTDFM is significantly improved due to the flux amplification. The optimal structure, which has maximum sensitivity enhancement, was obtained through FEM analysis. To validate the theoretical analysis, the optimal hybrid magnetometer was manufactured, and its performance was evaluated. The device has a sensitivity of 45 mV/nT at 1 kHz in IM mode and 0.38 μs/nT in RTDFM mode, which is approximately 3.45 times as large as that of the single RTDFM structure. Furthermore, to obtain a lower noise performance in the entire frequency band, two operation modes switch at the cross frequency (0.16 Hz) of their noise levels. The noise level is 30 pT/√Hz in RTDFM mode and 0.07 pT/√Hz at 1 kHz in IM mode.
One-electron atoms in screened modified gravity
Wong, Leong Khim; Davis, Anne-Christine
2017-05-01
In a large class of scalar-tensor theories that are potential candidates for dark energy, a nonminimal coupling between the scalar and the photon is possible. The presence of such an interaction grants us the exciting prospect of directly observing dark sector phenomenology in the electromagnetic spectrum. This paper investigates the behavior of one-electron atoms in this class of modified gravity models, exploring their viability as probes of deviations from general relativity in both laboratory and astrophysical settings. Building heavily on earlier studies, our main contribution is threefold: A thorough analysis finds additional fine-structure corrections previously unaccounted for, which now predict a contribution to the Lamb shift that is larger by nearly 4 orders of magnitude. In addition, they also predict a scalar-mediated photon-photon interaction, which now constrains the scalar's coupling to the photon independently of the matter coupling. This was not previously possible with atomic precision tests. Our updated constraints are log10βm≲13.4 and log10βγ≲19.0 for the matter and photon coupling, respectively, although these remain uncompetitive with bounds from other experiments. Second, we include the effects of the nuclear magnetic moment, allowing for the study of hyperfine structure and the 21 cm line, which hitherto have been unexplored in this context. Finally, we also examine how a background scalar leads to equivalence principle violations.
Scalar mesons and the search for the 0{sup ++} Glueball
Energy Technology Data Exchange (ETDEWEB)
Ulrike Thoma
2002-10-01
The possibility that gluonic excitations of hadronic matter or of the QCD vacuum may exist is perhaps one of the most fascinating topics in hadron spectroscopy. Glueballs are predicted by many models; in particular present-day lattice gauge calculations require their existence. All these models agree that the lightest glueball should have scalar quantum numbers and a mass around 1.6 GeV, which corresponds to the mass region where the scalar qq[bar]-mesons are expected. Therefore mixing effects can complicate the search for the glueball. Experiments indeed show an overpopulation of states, for which many different interpretations exist. This reflects the complexity of the situation. New data from various experiments on scalar states give hints toward an interpretation of the scalar states. But, still many questions remain.
Scalar mesons and the search for the 0{sup ++} glueball
Energy Technology Data Exchange (ETDEWEB)
Thoma, U. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
2003-11-01
The possibility that gluonic excitations of hadronic matter or of the QCD vacuum may exist is perhaps one of the most fascinating topics in hadron spectroscopy. Glueballs are predicted by many models; in particular, present-day lattice gauge calculations require their existence. All these models agree that the lightest glueball should have scalar quantum numbers and a mass around 1.6GeV, which corresponds to the mass region where the scalar q anti q-mesons are expected. Therefore, mixing effects can complicate the search for the glueball. Experiments indeed show an overpopulation of states, for which many different interpretations exist. This reflects the complexity of the situation. New data from various experiments on scalar states give hints toward an interpretation of the scalar states. But still many questions remain. (orig.)
Scalar and vector vortex beams from the source
CSIR Research Space (South Africa)
Naidoo, Darryl
2016-10-01
Full Text Available . Advanced Solid State Lasers 2016 (ASSL, LSC, LAC), OSA Technical Digest (online) (Optical Society of America, 2016), 30 October–3 November 2016, Boston, Massachusetts United States Scalar and vector vortex beams from the source Naidoo, Darryl Roux...
Holographic quantum phase transitions and interacting bulk scalars
Directory of Open Access Journals (Sweden)
Pankaj Chaturvedi
2014-12-01
Full Text Available We consider a system of two massive, mutually interacting probe real scalar fields, in zero temperature holographic backgrounds. The system does not have any continuous symmetry. For a suitable range of the interaction parameters adhering to the interaction potential between the bulk scalars, we have shown that as one turns on the source for one scalar field, the system may go through a second order quantum critical phase transition across which the second scalar field forms a condensate. We have looked at the resulting phase diagram and numerically computed the condensate. We have also investigated our system in two different backgrounds: AdS4 and AdS soliton, and got similar phase structure.
AdS gravity and the scalar glueball spectrum
Energy Technology Data Exchange (ETDEWEB)
Vento, Vicente [Departament de Fisica Teorica, Universitat de Valencia y Institut de Fisica Corpuscular, Consejo Superior de Investigaciones Cientificas, Burjassot (Valencia) (Spain)
2017-09-15
The scalar glueball spectrum has attracted much attention since the formulation of Quantum Chromodynamics. Different approaches give very different results for the glueball masses. We revisit the problem from the perspective of the AdS/CFT correspondence. (orig.)
Scalar perturbations of nonsingular nonrotating black holes in conformal gravity
Toshmatov, Bobir; Bambi, Cosimo; Ahmedov, Bobomurat; Stuchlík, Zdeněk; Schee, Jan
2017-09-01
We study scalar and electromagnetic perturbations of a family of nonsingular nonrotating black hole spacetimes that are solutions in a large class of conformally invariant theories of gravity. The effective potential for scalar perturbations depends on the exact form of the scaling factor. Electromagnetic perturbations do not feel the scaling factor, and the corresponding quasinormal mode spectrum is the same as in the Schwarzschild metric. We find that these black hole metrics are stable under scalar and electromagnetic perturbations. Assuming that the quasinormal mode spectrum for scalar perturbations is not too different from that for gravitational perturbations, we can expect that the calculation of the quasinormal mode spectrum and the observation with gravitational wave detectors of quasinormal modes from astrophysical black holes can constrain the scaling factor and test these solutions.
A nonlinear dynamics for the scalar field in Randers spacetime
Energy Technology Data Exchange (ETDEWEB)
Silva, J.E.G. [Universidade Federal do Cariri (UFCA), Instituto de formação de professores, Rua Olegário Emídio de Araújo, Brejo Santo, CE, 63.260.000 (Brazil); Maluf, R.V. [Universidade Federal do Ceará (UFC), Departamento de Física, Campus do Pici, Fortaleza, CE, C.P. 6030, 60455-760 (Brazil); Almeida, C.A.S., E-mail: carlos@fisica.ufc.br [Universidade Federal do Ceará (UFC), Departamento de Física, Campus do Pici, Fortaleza, CE, C.P. 6030, 60455-760 (Brazil)
2017-03-10
We investigate the properties of a real scalar field in the Finslerian Randers spacetime, where the local Lorentz violation is driven by a geometrical background vector. We propose a dynamics for the scalar field by a minimal coupling of the scalar field and the Finsler metric. The coupling is intrinsically defined on the Randers spacetime, and it leads to a non-canonical kinetic term for the scalar field. The nonlinear dynamics can be split into a linear and nonlinear regimes, which depend perturbatively on the even and odd powers of the Lorentz-violating parameter, respectively. We analyze the plane-waves solutions and the modified dispersion relations, and it turns out that the spectrum is free of tachyons up to second-order.
Evolution of Dark Energy Perturbations in Scalar-Tensor Cosmologies
Sanchez, J. C. Bueno; Perivolaropoulos, L.
2010-01-01
We solve analytically and numerically the generalized Einstein equations in scalar-tensor cosmologies to obtain the evolution of dark energy and matter linear perturbations. We compare our results with the corresponding results for minimally coupled quintessence perturbations. Our results for natural (O(1)) values of parameters in the Lagrangian which lead to a background expansion similar to LCDM are summarized as follows: 1. Scalar-Tensor dark energy density perturbations are amplified by a...
Topological defect solutions for a system of three scalar fields
Niazian, M. R.; Amani, Ali R.
2015-06-01
In this paper, we studied on the defect structures as topological by non-linear three scalar fields. By using modified Adomian decomposition method (MADM), and Adomian decomposition method (ADM) we have found the solutions of three scalar fields. Then we compared the obtained results each other by numerical solution. Also, we consider the static case and draw ϕ(x), χ(x), and ρ(x) with the choice of different values for parameter r.
Scalar perturbations of nonsingular nonrotating black holes in conformal gravity
Toshmatov, Bobir; Bambi, Cosimo; Ahmedov, Bobomurat; Stuchlík, Zdeněk; Schee, Jan
2017-01-01
We study scalar and electromagnetic perturbations of a family of nonsingular nonrotating black hole spacetimes that are solutions in a large class of conformally invariant theories of gravity. The effective potential for scalar perturbations depends on the exact form of the scaling factor. Electromagnetic perturbations do not feel the scaling factor, and the corresponding quasinormal mode spectrum is the same as in the Schwarzschild metric. We find that these black hole metrics are stable und...
Canonical Quantization of the Scalar Field: The Measure Theoretic Perspective
Velhinho, José
2015-01-01
This review is devoted to measure theoretical methods in the canonical quantization of scalar field theories. We present in some detail the canonical quantization of the free scalar field. We study the measures associated with the free fields and present two characterizations of the support of these measures. The first characterization concerns local properties of the quantum fields, whereas for the second one we introduce a sequence of variables that test the field behaviour at large distanc...
Two photon couplings of scalar and tensor mesons
Feindt, Michael; Harjes, Jens
1991-06-01
Experimental data on exclusive two photon reactions are investigated with respect to formation of tensor and scalar mesons. Theoretical and experimental status and progress is reviewed. Furthermore, new CELLO results on γγ → π-π- and γγ → ϱ0ϱ0 are presented. Clear evidence for a large scalar contribution is found in both reactions. The implications of these new results are discussed.
Brans-Dicke type teleparallel scalar-tensor theory
Salti, Mustafa; Aydogdu, Oktay; Yanar, Hilmi; Binbay, Figen
2017-11-01
The teleparallel alternative of general relativity which is based on torsion instead of curvature is considered as the gravitational sector to explore the dark universe. Inspired from the well-known Brans-Dicke gravity, here, we introduce a new proposal for the galactic dark energy effect. The new model includes a scalar field with self-interacting potential and a non-minimal coupling between the gravity and scalar field. Additionally, we analyze the idea via the Noether symmetry approach and thermodynamics.
Cosmological Brane World Solutions with Bulk Scalar Fields
Davis, Stephen C.
2001-01-01
Cosmological brane world solutions are found for five-dimensional bulk spacetimes with a scalar field. A supergravity inspired method for obtaining static solutions is combined with a method for finding brane cosmologies with constant bulk energies. This provides a way to generate full (bulk and brane) cosmological solutions to brane worlds with bulk scalar fields. Examples of these solutions, and their cosmological evolution, are discussed.
Extending Chiral Perturbation Theory with an Isosinglet Scalar
DEFF Research Database (Denmark)
Hansen, Martin; Langaeble, Kasper; Sannino, Francesco
2017-01-01
We augment the chiral Lagrangian by an isosinglet scalar and compute the one-loop radiative corrections to the pion mass and decay constant, as well as the scalar mass. The calculations are carried out for different patterns of chiral symmetry breaking of immediate relevance for phenomenology and...... and lattice investigations. By construction our results encompass several interesting limits, ranging from the dilaton to the linear sigma model....
Scalar transport in inline mixers with spatially periodic flows
Baskan, Ozge; Rajaei, Hadi; Speetjens, Michel F. M.; Clercx, Herman J. H.
2017-01-01
Spatially persisting patterns form during the downstream evolution of passive scalars in three-dimensional (3D) spatially periodic flows due to the coupled effect of stretching and folding mechanisms of the flow field. This has been investigated in many computational and theoretical studies of 2D time-periodic and 3D spatially periodic flow fields. However, experimental studies, to date, have mainly focused on flow visualization with streaks of dye rather than fully 3D scalar field measurements. Our study employs 3D particle tracking velocimetry and 3D laser-induced fluorescence to analyze the evolution of 3D flow and scalar fields and the correlation between the coherent flow/scalar field structures in a representative inline mixer, the Quatro static mixer. For this purpose an experimental setup that consists of an optically accessible test section with transparent internal elements accommodating a pressure-driven pipe flow has been built. The flow and scalar fields clearly underline the complementarity of the experimental results with numerical simulations and provide validation of the periodicity assumption needed in numerical studies. The experimental procedure employed in this investigation, which allows studying the scalar transport in the advective limit, demonstrates the suitability of the present method for exploratory mixing studies of a variety of mixing devices, beyond the Quatro static mixer.
Small vacuum energy from small equivalence violation in scalar gravity
Agrawal, Prateek; Sundrum, Raman
2017-05-01
The theory of scalar gravity proposed by Nordström, and refined by Einstein and Fokker, provides a striking analogy to general relativity. In its modern form, scalar gravity appears as the low-energy effective field theory of the spontaneous breaking of conformal symmetry within a CFT, and is AdS/CFT dual to the original Randall-Sundrum I model, but without a UV brane. Scalar gravity faithfully exhibits several qualitative features of the cosmological constant problem of standard gravity coupled to quantum matter, and the Weinberg no-go theorem can be extended to this case as well. Remarkably, a solution to the scalar gravity cosmological constant problem has been proposed, where the key is a very small violation of the scalar equivalence principle, which can be elegantly formulated as a particular type of deformation of the CFT. In the dual AdS picture this involves implementing Goldberger-Wise radion stabilization where the Goldberger-Wise field is a pseudo-Nambu Goldstone boson. In quantum gravity however, global symmetries protecting pNGBs are not expected to be fundamental. We provide a natural six-dimensional gauge theory origin for this global symmetry and show that the violation of the equivalence principle and the size of the vacuum energy seen by scalar gravity can naturally be exponentially small. Our solution may be of interest for study of non-supersymmetric CFTs in the spontaneously broken phase.
Fluctuations of a passive scalar in a turbulent mixing layer
Attili, Antonio
2013-09-19
The turbulent flow originating downstream of the Kelvin-Helmholtz instability in a mixing layer has great relevance in many applications, ranging from atmospheric physics to combustion in technical devices. The mixing of a substance by the turbulent velocity field is usually involved. In this paper, a detailed statistical analysis of fluctuations of a passive scalar in the fully developed region of a turbulent mixing layer from a direct numerical simulation is presented. Passive scalar spectra show inertial ranges characterized by scaling exponents −4/3 and −3/2 in the streamwise and spanwise directions, in agreement with a recent theoretical analysis of passive scalar scaling in shear flows [Celani et al., J. Fluid Mech. 523, 99 (2005)]. Scaling exponents of high-order structure functions in the streamwise direction show saturation of intermittency with an asymptotic exponent ζ∞=0.4 at large orders. Saturation of intermittency is confirmed by the self-similarity of the tails of the probability density functions of the scalar increments at different scales r with the scaling factor r−ζ∞ and by the analysis of the cumulative probability of large fluctuations. Conversely, intermittency saturation is not observed for the spanwise increments and the relative scaling exponents agree with recent results for homogeneous isotropic turbulence with mean scalar gradient. Probability density functions of the scalar increments in the three directions are compared to assess anisotropy.
Phenomenology of Bulk Scalar Production at the LHC
Beauchemin , Pierre-Hugues; Burgess, Cliff
We examine the sensitivity of the ATLAS detector to extra-dimensional scalars in scenarios having the extra-dimensional Planck scale in the TeV range and n = 2 large extra dimensions. Such scalars appear as partners of the graviton in higher-dimensional supersymmetric theories. Using first the scalar's lowest-dimensional effective couplings to quarks and gluons, we compute the rate of production of a hard jet together with missing energy. We find a nontrivial range of bulk scalar couplings for which ATLAS could observe a signal, and in particular, higher sensitivity to couplings to gluons than to quarks. Bulk scalar emission increases the missing-energy signal by adding to graviton production, and so complicates the inference of the extra-dimensional Planck scale from the observed rate of jet + EmissT . Because bulk scalar differential cross sections resemble those for gravitons, it is unlikely that these can be experimentally distinguished should a missing energy signal be observed. However, given, for examp...
Structure function of passive scalars in two-dimensional turbulence
Eckhardt, B; Eckhardt, Bruno; Schumacher, Joerg
1999-01-01
The structure function of a scalar $\\theta({\\bf x},t)$, passively advected in a two-dimensional turbulent flow ${\\bf u}({\\bf x},t)$, is discussed by means of the fractal dimension $\\delta^{(1)}_g$ of the passive scalar graph. A relation between $\\delta^{(1)}_g$, the scaling exponent $\\zeta_1^{(\\theta)}$ of the scalar structure function $D_1^{(\\theta)}(r)$, and the structure function $D_2(r)$ of the underlying flow field is derived. Different from the 3-d case, the 2-d structure function also depends on an additional parameter, characteristic of the driving of the passive scalar. In the enstrophy inertial subrange a mean field approximation for the velocity structure function gives a scaling of the passive scalar graph with $\\delta^{(1)}_g<2$ for intermediate and large values of the Prandtl number $Pr$. In the energy inertial subrange a model for the energy spectrum and thus $D_2(r)$ gives a passive scalar graph scaling with exponent $\\delta^{(1)}_g=5/3$. Finally, we discuss an application to recent observa...
A magnetometer-free indoor human localization based on loosely coupled IMU/UWB fusion.
Zihajehzadeh, Shaghayegh; Yoon, Paul K; Park, Edward J
2015-01-01
The magnetic distortions in indoor environment affects the accuracy of yaw angle estimation using magnetometer. Thus, the accuracy of indoor localization based on inertial-magnetic sensors will be affected as well. To address this issue, this paper proposes a magnetometer-free solution for indoor human localization and yaw angle estimation. The proposed algorithm fuses a wearable inertial sensor consisting of MEMS-based accelerometer and gyroscope with a portable ultra-wideband (UWB) localization system in a cascaded two-step filter consisting of a tilt Kalman filter and a localization Kalman filter. By benchmarking against an optical motion capture system, the experimental results show that the proposed algorithm can accurately track position and velocity as well as the yaw angle without using magnetometer.
Construction and calibration of a low cost and fully automated vibrating sample magnetometer
Energy Technology Data Exchange (ETDEWEB)
El-Alaily, T.M., E-mail: toson_alaily@yahoo.com [Physics Department, Faculty of Science, Tanta University, Tanta (Egypt); El-Nimr, M.K.; Saafan, S.A.; Kamel, M.M.; Meaz, T.M. [Physics Department, Faculty of Science, Tanta University, Tanta (Egypt); Assar, S.T. [Engineering Physics and Mathematics Department, Faculty of Engineering, Tanta University, Tanta (Egypt)
2015-07-15
A low cost vibrating sample magnetometer (VSM) has been constructed by using an electromagnet and an audio loud speaker; where both are controlled by a data acquisition device. The constructed VSM records the magnetic hysteresis loop up to 8.3 KG at room temperature. The apparatus has been calibrated and tested by using magnetic hysteresis data of some ferrite samples measured by two scientifically calibrated magnetometers; model (Lake Shore 7410) and model (LDJ Electronics Inc. Troy, MI). Our VSM lab-built new design proved success and reliability. - Highlights: • A low cost automated vibrating sample magnetometer VSM has been constructed. • The VSM records the magnetic hysteresis loop up to 8.3 KG at room temperature. • The VSM has been calibrated and tested by using some measured ferrite samples. • Our VSM lab-built new design proved success and reliability.
Direct numerical simulation of a passive scalar with imposed mean gradient in isotropic turbulence
Overholt, M. R.; Pope, S. B.
1996-11-01
Mixing of a passive scalar in statistically homogeneous, isotropic, and stationary turbulence with a mean scalar gradient is investigated via direct numerical simulation, for Taylor-scale Reynolds numbers, Rλ, from 28 to 185. Multiple independent simulations are performed to get confidence intervals, and local regression smoothing is used to further reduce statistical fluctuations. The scalar fluctuation field, φ(x,t), is initially zero, and develops to a statistically stationary state after about four eddy turnover times. Quantities investigated include the dissipation of scalar flux, which is found to be significant; probability density functions (pdfs) and joint-pdfs of the scalar, its derivatives, scalar dissipation, and mechanical dissipation; and conditional expectations of scalar mixing, ∇2φ. A linear model for scalar mixing jointly conditioned on the scalar and v-velocity is developed, and reproduces the data quite well. Also considered is scalar mixing jointly conditioned on the scalar and scalar dissipation. Terms appearing in the balance equation for the pdf of φ are examined. From a solution of the scalar pdf equation two sufficient conditions arise for the scalar pdf to be Gaussian. These are shown to be well satisfied for moderate values of the scalar, and approximately so for large fluctuations. Many correlations are also presented, including ρ(v,φ), which changes during the evolution of the scalar from a value of unity when initialized to the stationary value of 0.5-0.6.
DEFF Research Database (Denmark)
Menvielle, M.; Primdahl, Fritz; Brauer, Peter
as characterizing its sub-surface. Magnetic fields are generated by electric currents in the planetary space environment, induced currents in the planetary interior and possibly remanent magnetism. In consequence, hardly any other single physical quantity can be used in such a variety of studies related......Magnetic field observations at a planetary surface have a wide potential of scientific applications, ranging from processes in the dynamic interaction between the planet environment and the solar wind, to determining the structure and thermal evolution of the interior of the planet as well...... to planetary research. The major difficulty in implementing a magnetometer experiment onboard a lander is to achieve at acceptable costs a good Magnetometer Protection, namely to control the perturbing magnetic field generated by the lander during operations at the planetary surfa ce, so as to achieve...
Integrated high-transition temperature magnetometer with only two superconducting layers
DEFF Research Database (Denmark)
Kromann, R.; Kingston, J.J.; Miklich, A.H.
1993-01-01
We describe the fabrication and testing of an integrated YBa2Cu3O7-x thin-film magnetometer consisting of a dc superconducting quantum interference device (SQUID), with biepitaxial grain boundary junctions, integrated with a flux transformer on a single substrate. Only two superconducting layers...... are required, the SQUID body serving as the crossunder that completes the multiturn flux transformer. The highest temperature at which any of the magnetometers functioned was 76 K. At 60 K the magnetic field gain of this device was 63, and the magnetic field noise was 160 fT Hz-1/2 at 2 kHz, increasing to 3...
Study of 3He Rabi nutations by optically-pumped cesium magnetometers
Koch, Hans-Christian; Bison, Georg; Grujić, Zoran Dragan; Heil, Werner; Kasprzak, Malgorzata; Knowles, Paul; Kraft, Andreas; Pazgalev, Anatoly; Schnabel, Allard; Voigt, Jens; Weis, Antoine
2017-10-01
We describe a method for recording the Rabi nutation of nuclear spin polarized 3He by optically pumped cesium magnetometers. The measurement is performed by detecting the time-dependent magnetic field produced by the 3He magnetization. The observed signals are compared to theoretical models and the results are used to precisely trace the evolution of the magnetization. This procedure represents a convenient way to control and measure the Rabi flip angle and the degree of spin polarization in experiments using 3He magnetometers. The method requires only very coarse knowledge of the applied magnetic field's magnitude.
De Roeck, A.; Hirt, A M; Joergensen, M-D; Katre, A; Mermod, P; Milstead, D; Sloan, T
2012-01-01
If produced in high energy particle collisions at the LHC, magnetic monopoles could stop in material surrounding the interaction points. Obsolete parts of the beam pipe near the CMS interaction region, which were exposed to the products of pp and heavy ion collisions, were analysed using a SQUID-based magnetometer. The purpose of this work is to quantify the performance of the magnetometer in the context of a monopole search using a small set of samples of accelerator material ahead of the 2013 shutdown.
Ignat'ev, Yu G
2013-01-01
On the basis of the relativistic kinetic theory the mathematical model of cosmological plasmas with an attraction of the like charged scalar particles is formulated. It is shown, that cosmological the model, based on a classical scalar field with an attraction, is unsatisfactory, that leads to necessity of attraction of phantom models of a scalar field for systems with an attraction.
Arbitrary scalar-field and quintessence cosmological models
Energy Technology Data Exchange (ETDEWEB)
Harko, Tiberiu [University College London, Department of Mathematics, London (United Kingdom); Lobo, Francisco S.N. [Centro de Astronomia e Astrofisica da Universidade de Lisboa, Lisbon (Portugal); Mak, M.K. [Hong Kong Institute of Vocational Education, Department of Computing and Information Management, Hong Kong (China)
2014-03-15
The mechanism of the initial inflationary scenario of the Universe and of its late-time acceleration can be described by assuming the existence of some gravitationally coupled scalar fields φ, with the inflaton field generating inflation and the quintessence field being responsible for the late accelerated expansion. Various inflationary and late-time accelerated scenarios are distinguished by the choice of an effective self-interaction potential V(φ), which simulates a temporarily non-vanishing cosmological term. In this work, we present a new formalism for the analysis of scalar fields in flat isotropic and homogeneous cosmological models. The basic evolution equation of the models can be reduced to a first-order non-linear differential equation. Approximate solutions of this equation can be constructed in the limiting cases of the scalar-field kinetic energy and potential energy dominance, respectively, as well as in the intermediate regime. Moreover, we present several new accelerating and decelerating exact cosmological solutions, based on the exact integration of the basic evolution equation for scalar-field cosmologies. More specifically, exact solutions are obtained for exponential, generalized cosine hyperbolic, and power-law potentials, respectively. Cosmological models with power-law scalar field potentials are also analyzed in detail. (orig.)
Long-lived, colour-triplet scalars from unnaturalness
Energy Technology Data Exchange (ETDEWEB)
Barnard, James; Cox, Peter [ARC Centre of Excellence for Particle Physics at the Terascale,School of Physics, The University of Melbourne,Victoria 3010 (Australia); Gherghetta, Tony [School of Physics and Astronomy, University of Minnesota,Minneapolis, Minnesota 55455 (United States); Spray, Andrew [ARC Centre of Excellence for Particle Physics at the Terascale,School of Physics, The University of Melbourne,Victoria 3010 (Australia); Center for Theoretical Physics of the Universe, Institute for Basic Science (IBS),Daejeon, 34051 (Korea, Republic of)
2016-03-01
Long-lived, colour-triplet scalars are a generic prediction of unnatural, or split, composite Higgs models where the spontaneous global-symmetry breaking scale f≳10 TeV and an unbroken SU(5) symmetry is preserved. Since the triplet scalars are pseudo Nambu-Goldstone bosons they are split from the much heavier composite-sector resonances and are the lightest exotic, coloured states. This makes them ideal to search for at colliders. Due to discrete symmetries the triplet scalar decays via a dimension-six term and given the large suppression scale f is often metastable. We show that existing searches for collider-stable R-hadrons from Run-I at the LHC forbid a triplet scalar mass below 845 GeV, whereas with 300 fb{sup −1} at 13 TeV triplet scalar masses up to 1.4 TeV can be discovered. For shorter lifetimes displaced-vertex searches provide a discovery reach of up to 1.8 TeV. In addition we present exclusion and discovery reaches of future hadron colliders as well as indirect limits that arise from modifications of the Higgs couplings.
DEFF Research Database (Denmark)
Weygand, J. M.; Amm, O.; Angelopoulos, V.
2012-01-01
that may influence the alignment include ionospheric conductivity gradients and quiet time backgrounds. Our results can be used to approximate the macroscopic (similar to 1000 km) ionospheric convection patterns. The SECS maps represent a value-added product from the raw magnetometer database and can...
DEFF Research Database (Denmark)
Wisniewski, Rafal; Stoustrup, Jakob
2001-01-01
the expected magnetic field vector and the true magnetometer data is used for the attitude determination. The magnetic attitude control and determination is intrinsically periodic due to periodic nature of the geomagnetic field variation in orbit. The control performance is specified by the generalized H2...
MgB2 magnetometer with directly coupled pick-up loop
Portesi, C.; Mijatovic, D.; Veldhuis, Dick; Brinkman, Alexander; Monticone, E.; Gonnelli, R.S.
2006-01-01
magnetometer with a directly coupled pick-up loop. We used an all in situ technique for fabricating magnesium diboride films, which consists of the co-evaporation of B and Mg by means of an e-gun and a resistive heater respectively. Consequently, we realized the superconducting device, which
Directory of Open Access Journals (Sweden)
Daehee Won
2015-01-01
Full Text Available A navigation algorithm is proposed to increase the inertial navigation performance of a ground vehicle using magnetic measurements and dynamic constraints. The navigation solutions are estimated based on inertial measurements such as acceleration and angular velocity measurements. To improve the inertial navigation performance, a three-axis magnetometer is used to provide the heading angle, and nonholonomic constraints (NHCs are introduced to increase the correlation between the velocity and the attitude equation. The NHCs provide a velocity feedback to the attitude, which makes the navigation solution more robust. Additionally, an acceleration-based roll and pitch estimation is applied to decrease the drift when the acceleration is within certain boundaries. The magnetometer and NHCs are combined with an extended Kalman filter. An experimental test was conducted to verify the proposed method, and a comprehensive analysis of the performance in terms of the position, velocity, and attitude showed that the navigation performance could be improved by using the magnetometer and NHCs. Moreover, the proposed method could improve the estimation performance for the position, velocity, and attitude without any additional hardware except an inertial sensor and magnetometer. Therefore, this method would be effective for ground vehicles, indoor navigation, mobile robots, vehicle navigation in urban canyons, or navigation in any global navigation satellite system-denied environment.
Kawai, J.; Miyamoto, M.; Kawabata, M.; Nosé, M.; Haruta, Y.; Uehara, G.
2017-08-01
We characterized a low temperature superconducting quantum interference device (SQUID) magnetometer system developed for high-sensitivity geomagnetic field measurement, and demonstrated the detection of weak geomagnetic signals. The SQUID magnetometer system is comprised of three-axis SQUID magnetometers housed in a glass fiber reinforced plastic cryostat, readout electronics with flux locked loop (FLL), a 24-bit data logger with a global positioning system and batteries. The system noise was approximately 0.2 pT √Hz- 1/2 in the 1-50 Hz frequency range. This performance was determined by including the thermal noise and the shielding effect of the copper shield, which covered the SQUID magnetometers to eliminate high-frequency interference. The temperature drift of the system was ˜0.8 pT °C- 1 in an FLL operation. The system operated for a month using 33 l liquid helium. Using this system, we performed the measurements of geomagnetic field in the open-air, far away from the city. The system could detect weak geomagnetic signals such as the Schumann resonance with sixth harmonics, and the ionospheric Alfvén resonance appearing at night, for the north-south and east-west components of the geomagnetic field. We confirm that the system was capable of high-sensitivity measurement of the weak geomagnetic activities.
Progress toward observation of quantum interference of currents in an Atom SQUID
Ryu, Changhyun; Samson, E. Carlo; Boshier, Malcolm
2016-05-01
Quantum interference of currents was first observed in a superconducting loop with two Josephson junctions, leading to the name ``SQUID'' for this device. This interference effect has been used to develop extremely sensitive magnetometers. The Atom SQUID, an analogous device based on ultracold atoms, has been developed recently to study SQUID physics in a device offering a better understanding of the underlying microscopic dynamics. Although many exciting experiments have been done with Atom SQUIDs, the quantum interference of currents has not yet been observed. In analogy with the SQUID magnetometer, it should be possible to use the quantum interference effect in an Atom SQUID to measure rotation, which may lead to the development of a sensitive gyroscope. In a previous experiment, we showed Josephson effects with an atom SQUID by observing the change from the dc Josephson regime to the ac Josephson regime by measurement of the critical atom number for this transition. Quantum interference should cause this critical atom number to vary with rotation rate. We have simulated this system with the Gross-Pitaevski Equation and found the expected oscillatory change of the critical atom number. We will present this simulation result and report the current status of our experiment to
Loring, FH
2014-01-01
Summarising the most novel facts and theories which were coming into prominence at the time, particularly those which had not yet been incorporated into standard textbooks, this important work was first published in 1921. The subjects treated cover a wide range of research that was being conducted into the atom, and include Quantum Theory, the Bohr Theory, the Sommerfield extension of Bohr's work, the Octet Theory and Isotopes, as well as Ionisation Potentials and Solar Phenomena. Because much of the material of Atomic Theories lies on the boundary between experimentally verified fact and spec
A game-theoretic approach for calibration of low-cost magnetometers under noise uncertainty
Siddharth, S.; Ali, A. S.; El-Sheimy, N.; Goodall, C. L.; Syed, Z. F.
2012-02-01
Pedestrian heading estimation is a fundamental challenge in Global Navigation Satellite System (GNSS)-denied environments. Additionally, the heading observability considerably degrades in low-speed mode of operation (e.g. walking), making this problem even more challenging. The goal of this work is to improve the heading solution when hand-held personal/portable devices, such as cell phones, are used for positioning and to improve the heading estimation in GNSS-denied signal environments. Most smart phones are now equipped with self-contained, low cost, small size and power-efficient sensors, such as magnetometers, gyroscopes and accelerometers. A magnetometer needs calibration before it can be properly employed for navigation purposes. Magnetometers play an important role in absolute heading estimation and are embedded in many smart phones. Before the users navigate with the phone, a calibration is invoked to ensure an improved signal quality. This signal is used later in the heading estimation. In most of the magnetometer-calibration approaches, the motion modes are seldom described to achieve a robust calibration. Also, suitable calibration approaches fail to discuss the stopping criteria for calibration. In this paper, the following three topics are discussed in detail that are important to achieve proper magnetometer-calibration results and in turn the most robust heading solution for the user while taking care of the device misalignment with respect to the user: (a) game-theoretic concepts to attain better filter parameter tuning and robustness in noise uncertainty, (b) best maneuvers with focus on 3D and 2D motion modes and related challenges and (c) investigation of the calibration termination criteria leveraging the calibration robustness and efficiency.
Center phase transition from matter propagators in (scalar) QCD
Mitter, M.; Hopfer, M.; Schaefer, B.-J.; Alkofer, R.
2018-02-01
Novel order parameters for the confinement-deconfinement phase transition of quenched QCD and fundamentally charged scalar QCD are presented. Similar to the well-known dual condensate, they are defined via generalized matter propagators with U (1)-valued boundary conditions. The order parameters are easily accessible with functional methods. Their validity and accessibility is explicitly demonstrated by numerical studies of the Dyson-Schwinger equations for the matter propagators. Even in the case of heavy scalar matter, where the propagator does not show a signature of the phase transition, a discontinuity due to the transition can be extracted in the order parameters, establishing also fundamentally charged scalar matter as a probe for color confinement.
Scalar multiplet recombination at large N and holography
Energy Technology Data Exchange (ETDEWEB)
Bashmakov, Vladimir [SISSA and INFN, Via Bonomea 265, I-34136 Trieste (Italy); Bertolini, Matteo [SISSA and INFN, Via Bonomea 265, I-34136 Trieste (Italy); ICTP, Strada Costiera 11, I-34014 Trieste (Italy); Pietro, Lorenzo Di [Weizmann Institute of Science, Rehovot 7610001 (Israel); Raj, Himanshu [SISSA and INFN, Via Bonomea 265, I-34136 Trieste (Italy)
2016-05-31
We consider the coupling of a free scalar to a single-trace operator of a large N CFT in d dimensions. This is equivalent to a double-trace deformation coupling two primary operators of the CFT, in the limit when one of the two saturates the unitarity bound. At leading order, the RG-flow has a non-trivial fixed point where multiplets recombine. We show this phenomenon in field theory, and provide the holographic dual description. Free scalars correspond to singleton representations of the AdS algebra. The double-trace interaction is mapped to a boundary condition mixing the singleton with the bulk field dual to the single-trace operator. In the IR, the singleton and the bulk scalar merge, providing just one long representation of the AdS algebra.
Thermodynamics of perfect fluids from scalar field theory
Ballesteros, Guillermo; Pilo, Luigi
2016-01-01
The low-energy dynamics of relativistic continuous media is given by a shift-symmetric effective theory of four scalar fields. These scalars describe the embedding in spacetime of the medium and play the role of Stuckelberg fields for spontaneously broken spatial and time translations. Perfect fluids are selected imposing a stronger symmetry group or reducing the field content to a single scalar. We explore the relation between the field theory description of perfect fluids to thermodynamics. By drawing the correspondence between the allowed operators at leading order in derivatives and the thermodynamic variables, we find that a complete thermodynamic picture requires the four Stuckelberg fields. We show that thermodynamic stability plus the null energy condition imply dynamical stability. We also argue that a consistent thermodynamic interpretation is not possible if any of the shift symmetries is explicitly broken.
Scalar field dark matter and the Higgs field
Directory of Open Access Journals (Sweden)
O. Bertolami
2016-08-01
Full Text Available We discuss the possibility that dark matter corresponds to an oscillating scalar field coupled to the Higgs boson. We argue that the initial field amplitude should generically be of the order of the Hubble parameter during inflation, as a result of its quasi-de Sitter fluctuations. This implies that such a field may account for the present dark matter abundance for masses in the range 10−6–10−4eV, if the tensor-to-scalar ratio is within the range of planned CMB experiments. We show that such mass values can naturally be obtained through either Planck-suppressed non-renormalizable interactions with the Higgs boson or, alternatively, through renormalizable interactions within the Randall–Sundrum scenario, where the dark matter scalar resides in the bulk of the warped extra-dimension and the Higgs is confined to the infrared brane.
Investigation of Scalar Implicatures of Binus University Students
Directory of Open Access Journals (Sweden)
Clara Herlina Karjo
2011-01-01
Full Text Available Scalar implicatures are based on a range of quantifiers ordered in terms of informational strength, for example in quantity: some, most, all; in frequency: sometimes, often, and always. This study measures the scalar implicatures among university students who learn English as a foreign language. The participants for this study are fourth semester English Department students at Binus University. Using the same instruments as in Slabakova (2009 and Noveck’s study (2001 the present study aims to find out the general ability of the university students of computing scalar implicatures and to discover the level of pragmatic/logical competence of the university students with regards to their gender and grade point average. The results show that the students with GPA lower than three are more logical than those with GPA higher than three; while female students are more pragmatic than male students.
Inert scalars and vacuum metastability around the electroweak scale
Energy Technology Data Exchange (ETDEWEB)
Świeżewska, Bogumiła [Faculty of Physics, University of Warsaw,Pasteura 5, 02-093 Warsaw (Poland)
2015-07-22
We analyse effective potential around the electroweak (EW) scale in the Standard Model (SM) extended with a heavy scalar doublet. We show that the additional scalars can have a strong impact on vacuum stability. Although the additional heavy scalars may improve the behaviour of running Higgs self-coupling at large field values, we prove that they can destabilise the vacuum due to EW-scale effects. A new EW symmetry conserving minimum of the effective potential can appear rendering the electroweak symmetry breaking (EWSB) minimum meta- or unstable. However, for the case of the inert doublet model (IDM) with a 125 GeV Higgs boson we demonstrate that the parameter space region where the vacuum is meta- or unstable cannot be reconciled with the constraints from perturbative unitarity, electroweak precision tests (EWPT) and dark matter relic abundance measurements.
Brief History of Ultra-light Scalar Dark Matter Models
Lee, Jae-Weon
2018-01-01
This is a review on the brief history of the scalar field dark matter model also known as fuzzy dark matter, BEC dark matter, wave dark matter, or ultra-light axion. In this model ultra-light scalar dark matter particles with mass m = O(10-22)eV condense in a single Bose-Einstein condensate state and behave collectively like a classical wave. Galactic dark matter halos can be described as a self-gravitating coherent scalar field configuration called boson stars. At the scale larger than galaxies the dark matter acts like cold dark matter, while below the scale quantum pressure from the uncertainty principle suppresses the smaller structure formation so that it can resolve the small scale crisis of the conventional cold dark matter model.
Signatures of photon-scalar interaction in astrophysical situations
Ganguly, Avijit K.; Jaiswal, Manoj K.
2018-01-01
Dimension-5 photon ( γ) scalar ( ϕ) interaction term usually appear in the Lagrangians of bosonic sector of unified theories of electromagnetism and gravity. This interaction makes the medium dichoric and induces optical activity. Considering a toy model of an ultra-cold magnetized compact star (white dwarf (WD) or neutron star (NS)), we have modeled the propagation of very low energy photons with such interaction, in the environment of these stars. Assuming synchro-curvature process as the dominant mechanism of emission in such environments, we have tried to understand the polarimetric implications of photon-scalar coupling on the produced spectrum of the same. Further more assuming the `emission-energy vs emission-altitude' relation, that is believed to hold in such ( i.e., cold magnetized WD or NS) environments, we have tried to point out the possible modifications to the radiation spectrum when the same is incorporated along with dimension-5 photon-scalar mixing operator.
Unified cosmology with scalar-tensor theory of gravity
Energy Technology Data Exchange (ETDEWEB)
Tajahmad, Behzad [Faculty of Physics, University of Tabriz, Tabriz (Iran, Islamic Republic of); Sanyal, Abhik Kumar [Jangipur College, Department of Physics, Murshidabad (India)
2017-04-15
Unlike the Noether symmetry, a metric independent general conserved current exists for non-minimally coupled scalar-tensor theory of gravity if the trace of the energy-momentum tensor vanishes. Thus, in the context of cosmology, a symmetry exists both in the early vacuum and radiation dominated era. For slow roll, symmetry is sacrificed, but at the end of early inflation, such a symmetry leads to a Friedmann-like radiation era. Late-time cosmic acceleration in the matter dominated era is realized in the absence of symmetry, in view of the same decayed and redshifted scalar field. Thus, unification of early inflation with late-time cosmic acceleration with a single scalar field may be realized. (orig.)
Bounded Scalar Perturbations in Bouncing Brane World Cosmologies
Maier, Rodrigo; Soares, Ivano Damião
2013-01-01
We examine the dynamics of scalar perturbations in closed Friedmann-Lema\\^itre-Robertson- Walker (FLRW) universes in the framework of Brane World theory with a timelike extra dimension. In this scenario, the unperturbed Friedmann equations contain additional terms arising from the bulk-brane interaction that implement non-singular bounces in the models with a cosmological constant and non-interacting perfect fluids. The structure of the phase-space of the models allows for two basic configurations, namely, one bounce solutions or eternal universes. Assuming that the matter content of the model is given by dust and radiation, we derive the dynamical field equations for scalar hydrodynamical perturbations considering either a conformally flat (de Sitter) bulk or a perturbed bulk. We perform a numerical analysis which can shed some light on the study of cosmological scalar perturbations in bouncing brane world models. From a mathematical point of view we show that although the bounce enhances the amplitudes of s...
Leading-twist distribution amplitudes of scalar and vector mesons
Energy Technology Data Exchange (ETDEWEB)
Li, B. -L.; Chang, L.; Ding, M.; Roberts, C. D.; Zong, H. -S.
2016-11-01
A symmetry-preserving truncation of the two-body light-quark bound-state problem in relativistic quantum field theory is used to calculate the leading-twist parton distribution amplitudes (PDAs) of scalar systems, both ground-state and radial excitations, and the radial excitations of vector mesons. Owing to the fact that the scale-independent leptonic decay constant of a scalar meson constituted from equal-mass valence-constituents vanishes, it is found that the PDA of a given scalar system possesses one more zero than that of an analogous vector meson. Consequently, whereas the mean light-front relative momentum of the valence-constituents within a vector meson is zero, that within a scalar meson is large, an outcome which hints at a greater role for light-front angular momentum in systems classified as P-wave in quantum mechanical models. Values for the scale-dependent decay constants of ground-state scalar and vector systems are a by-product of this analysis, and they turn out to be roughly equal, viz. ≃ 0.2 GeV at an hadronic scale. In addition, it is confirmed that the dilation characterising ground-state PDAs is manifest in the PDAs of radial excitations too. The impact of SU(3)-flavour symmetry breaking is also considered. When compared with pseudoscalar states, it is a little stronger in scalar systems, but the size is nevertheless determined by the flavour-dependence of dynamical chiral symmetry breaking and the PDAs are still skewed toward the heavier valence-quark in asymmetric systems.
African Journals Online (AJOL)
Atomic Power. By Denis Taylor: Dr. Taylor was formerly Chief UNESCO Advisor at the University. College, Nairobi, Kenya and is now Professor of Electrical Engineering in the Uni- versity of ... method of producing radioactive isotopes, which are materials .... the sealing and the pressure balancing, all can be carried out ...
Brief History of Ultra-light Scalar Dark Matter Models
Directory of Open Access Journals (Sweden)
Lee Jae-Weon
2018-01-01
dark matter, BEC dark matter, wave dark matter, or ultra-light axion. In this model ultra-light scalar dark matter particles with mass m = O(10-22eV condense in a single Bose-Einstein condensate state and behave collectively like a classical wave. Galactic dark matter halos can be described as a self-gravitating coherent scalar field configuration called boson stars. At the scale larger than galaxies the dark matter acts like cold dark matter, while below the scale quantum pressure from the uncertainty principle suppresses the smaller structure formation so that it can resolve the small scale crisis of the conventional cold dark matter model.
Statistical Cosmological Fermion Systems With Interparticle Fantom Scalar Interaction
Ignat'ev, Yurii; Ignatyev, Dmitry
2016-01-01
The article represents a research of the cosmological evolution of fermion statistical systems with fantom scalar interaction where "kinetic" term's contribution to the total energy of a scalar field is negative. As a result of analytical and numerical simulation of such systems it has been revealed a existence of four possible scenarios depending on parameters of the system and initial conditions. Among these scenarios there are scenarios with an early, intermediate and late non-relativistic stages of the cosmological evolution, all of which also have necessary inflation stage.
Canonical Quantization of the Scalar Field: The Measure Theoretic Perspective
Directory of Open Access Journals (Sweden)
José Velhinho
2015-01-01
Full Text Available This review is devoted to measure theoretical methods in the canonical quantization of scalar field theories. We present in some detail the canonical quantization of the free scalar field. We study the measures associated with the free fields and present two characterizations of the support of these measures. The first characterization concerns local properties of the quantum fields, whereas for the second one we introduce a sequence of variables that test the field behaviour at large distances, thus allowing distinguishing between the typical quantum fields associated with different values of the mass.
Geometric scalar theory of gravity beyond spherical symmetry
Moschella, U.; Novello, M.
2017-04-01
We construct several exact solutions for a recently proposed geometric scalar theory of gravity. We focus on a class of axisymmetric geometries and a big-bang-like geometry and discuss their Lorentzian character. The axisymmetric solutions are parametrized by an integer angular momentum l . The l =0 (spherical) case gives rise to the Schwarzschild geometry. The other solutions have naked singular surfaces. While not a priori obvious, all the solutions that we present here are globally Lorentzian. The Lorentzian signature appears to be a robust property of the disformal geometries solving the vacuum geometric scalar theory of gravity equations.
Quantum Prisoners' Dilemma in Fluctuating Massless Scalar Field
Huang, Zhiming
2017-12-01
Quantum systems are easily affected by external environment. In this paper, we investigate the influences of external massless scalar field to quantum Prisoners' Dilemma (QPD) game. We firstly derive the master equation that describes the system evolution with initial maximally entangled state. Then, we discuss the effects of a fluctuating massless scalar field on the game's properties such as payoff, Nash equilibrium, and symmetry. We find that for different game strategies, vacuum fluctuation has different effects on payoff. Nash equilibrium is broken but the symmetry of the game is not violated.
Scalar dark matter in scale invariant standard model
Energy Technology Data Exchange (ETDEWEB)
Ghorbani, Karim [Physics Department, Faculty of Sciences,Arak University, Arak 38156-8-8349 (Iran, Islamic Republic of); Ghorbani, Hossein [Institute for Research in Fundamental Sciences (IPM),School of Particles and Accelerators, P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)
2016-04-05
We investigate single and two-component scalar dark matter scenarios in classically scale invariant standard model which is free of the hierarchy problem in the Higgs sector. We show that despite the very restricted space of parameters imposed by the scale invariance symmetry, both single and two-component scalar dark matter models overcome the direct and indirect constraints provided by the Planck/WMAP observational data and the LUX/Xenon100 experiment. We comment also on the radiative mass corrections of the classically massless scalon that plays a crucial role in our study.
Scalar ether theory of gravity: a modification that seems needed
Arminjon, Mayeul
2004-01-01
The construction of the scalar theory based on the concept of gravity as Archimedes' thrust is briefly summarized, emphasizing the two (extreme) possibilities that result from this concept for the gravitational rod contraction: it can either occur in only one direction, or be isotropic. A modified equation for the scalar field is stated for the new, isotropic case. The reasons to consider this case are: i) it is almost as natural as the other case, and ii) it should avoid the violation of the...
Small scale structures in coupled scalar field dark matter
Directory of Open Access Journals (Sweden)
J. Beyer
2014-11-01
Full Text Available We investigate structure formation for ultra-light scalar field dark matter coupled to quintessence, in particular the cosmon–bolon system. The linear power spectrum is computed by a numerical solution of the coupled field equations. We infer the substructure abundance within a Milky Way-like halo. Estimates of dark halo abundances from recent galaxy surveys imply a lower bound on the bolon mass of about 9×10−22 eV. This seems to exclude a possible detection of scalar field dark matter through time variation in pulsar timing signals in the near future.
Multi-Scalar Modelling for Free-form Timber Structures
DEFF Research Database (Denmark)
Poinet, Paul; Nicholas, Paul; Tamke, Martin
2016-01-01
This paper describes a new conceptual and computational framework that employs Multi-Scalar Modelling techniques (Weinan [22]) in order to overcome the problem of big data management and to enable a more integrative digital workflow during the geometrical discretization of spatial structures...... to integrate and negotiate the different parameters that drive the same segmentation strategy within a continuous environment. The research is developed in close collaboration with two industry partners – Buro Happold and DesignToProduction – and focuses on the implementation of Multi-Scalar Modelling concepts...
The Scalar Mesons, Symmetry Breaking, Three Colors and Confinement
Tornqvist, Nils A.
2006-01-01
The same, well known, det(Sigma)+ h.c. term in effective theories, which 't Hooft showed is generated by instantons in QCD and which resolves the UA(1) problem giving mass, in particular to the $\\eta'$ is for three light flavors shown to give three classical minima along the UA(1) circle. The three minima are related to the Z(3) center of SU(3). The term also contributes, in a similar way as the diquark model of Jaffe, to an inverted scalar mass spectrum for the light scalars. The three vacua...
Scalar-tensor theory of gravitation with negative coupling constant
Smalley, L. L.; Eby, P. B.
1976-01-01
The possibility of a Brans-Dicke scalar-tensor gravitation theory with a negative coupling constant is considered. The admissibility of a negative-coupling theory is investigated, and a simplified cosmological solution is obtained which allows a negative derivative of the gravitation constant. It is concluded that a Brans-Dicke theory with a negative coupling constant can be a viable alternative to general relativity and that a large negative value for the coupling constant seems to bring the original scalar-tensor theory into close agreement with perihelion-precession results in view of recent observations of small solar oblateness.
Atomic magnetic gradiometer for room temperature high sensitivity magnetic field detection
Xu, Shoujun [Berkeley, CA; Lowery, Thomas L [Belmont, MA; Budker, Dmitry [El Cerrito, CA; Yashchuk, Valeriy V [Richmond, CA; Wemmer, David E [Berkeley, CA; Pines, Alexander [Berkeley, CA
2009-08-11
A laser-based atomic magnetometer (LBAM) apparatus measures magnetic fields, comprising: a plurality of polarization detector cells to detect magnetic fields; a laser source optically coupled to the polarization detector cells; and a signal detector that measures the laser source after being coupled to the polarization detector cells, which may be alkali cells. A single polarization cell may be used for nuclear magnetic resonance (NMR) by prepolarizing the nuclear spins of an analyte, encoding spectroscopic and/or spatial information, and detecting NMR signals from the analyte with a laser-based atomic magnetometer to form NMR spectra and/or magnetic resonance images (MRI). There is no need of a magnetic field or cryogenics in the detection step, as it is detected through the LBAM.
Development of Geomagnetic Monitoring System Using a Magnetometer for the Field
Lee, Young-Cheol; Kim, Sung-Wook; Choi, Eun-Kyeong; Kim, In-Soo
2014-05-01
Three institutes including KMA (Korea Meteorological Administration), KSWC (Korean Space Weather Center) of NRRA (National Radio Research Agency) and KIGAM (Korea Institute of Geoscience and Mineral Resources) are now operating magnetic observatories. Those observatories observe the total intensity and three components of geomagnetic element. This paper comes up with a magnetic monitoring system now under development that uses a magnetometer for field survey. In monitoring magnetic variations in areas (active faults or volcanic regions), more reliable results can be obtained when an array of several magnetometers are used rather than a single magnetometer. In order to establish and operate a magnetometer array, such factors as expenses, convenience of the establishment and operation of the array should be taken into account. This study has come up with a magnetic monitoring system complete with a magnetometer for the field survey of our own designing. A magnetic monitoring system, which is composed of two parts. The one is a field part and the other a data part. The field part is composed of a magnetometer, an external memory module, a power supply and a set of data transmission equipment. The data part is a data server which can store the data transmitted from the field part, analyze the data and provide service to the web. This study has developed an external memory module for ENVI-MAG (Scintrex Ltd.) using an embedded Cortex-M3 board, which can be programmed, attach other functional devices (SD memory cards, GPS antennas for time synchronization, ethernet cards and so forth). The board thus developed can store magnetic measurements up to 8 Gbytes, synchronize with the GPS time and transmit the magnetic measurements to the data server which is now under development. A monitoring system of our own developing was installed in Jeju island, taking measurements throughout Korea. Other parts including a data transfer module, a server and a power supply using solar
Crease, Robert P.
2009-01-01
The American composer John Adams uses opera to dramatize controversial current events. His 1987 work Nixon in China was about the landmark meeting in 1972 between US President Richard Nixon and Chairman Mao Zedong of China; The Death of Klinghoffer (1991) was a musical re-enactment of an incident in 1985 when Palestinian terrorists kidnapped and murdered a wheelchair-bound Jewish tourist on a cruise ship. Adams's latest opera, Doctor Atomic, is also tied to a controversial event: the first atomic-bomb test in Alamogordo, New Mexico, on 16 June 1945. The opera premièred in San Francisco in 2005, had a highly publicized debut at the Metropolitan Opera in New York in 2008, and will have another debut on 25 February - with essentially the same cast - at the English National Opera in London.
Energy Technology Data Exchange (ETDEWEB)
Goldschmidt, B.
1990-01-01
This book is a memoir of rivalries among the Allies over the bomb, by a participant and observer. Nuclear proliferation began in the uneasy wartime collaboration of the United States, England, Canada, and Free France to produce the atom bomb. Through the changes of history, a young French chemist had a role in almost every act of this international drama. This memoir is based on Goldschmidt's own recollections, interviews with other leading figures, and 3,000 pages of newly declassified documents in Allied archives. From his own start as Marie Curie's lab assistant, Goldschmidt's career was closely intertwined with Frances complicated rise to membership in the nuclear club. As a refugee from the Nazis, he became part of the wartime nuclear energy project in Canada and found himself the only French scientist to work (although briefly) on the American atom bomb project.
Li, Chen; Zhou, Tianwei; Zhai, Yueyang; Xiang, Jinggang; Luan, Tian; Huang, Qi; Yang, Shifeng; Xiong, Wei; Chen, Xuzong
2017-05-01
We report a setup for the deep cooling of atoms in an optical trap. The deep cooling is implemented by eliminating the influence of gravity using specially constructed magnetic coils. Compared to the conventional method of generating a magnetic levitating force, the lower trap frequency achieved in our setup provides a lower limit of temperature and more freedoms to Bose gases with a simpler solution. A final temperature as low as ˜ 6 nK is achieved in the optical trap, and the atomic density is decreased by nearly two orders of magnitude during the second stage of evaporative cooling. This deep cooling of optically trapped atoms holds promise for many applications, such as atomic interferometers, atomic gyroscopes, and magnetometers, as well as many basic scientific research directions, such as quantum simulations and atom optics.
Scalar conservation and boundedness in simulations of compressible flow
Subbareddy, Pramod K.; Kartha, Anand; Candler, Graham V.
2017-11-01
With the proper combination of high-order, low-dissipation numerical methods, physics-based subgrid-scale models, and boundary conditions it is becoming possible to simulate many combustion flows at relevant conditions. However, non-premixed flows are a particular challenge because the thickness of the fuel/oxidizer interface scales inversely with Reynolds number. Sharp interfaces can also be present in the initial or boundary conditions. When higher-order numerical methods are used, there are often aphysical undershoots and overshoots in the scalar variables (e.g. passive scalars, species mass fractions or progress variable). These numerical issues are especially prominent when low-dissipation methods are used, since sharp jumps in flow variables are not always coincident with regions of strong variation in the scalar fields: consequently, special detection mechanisms and dissipative fluxes are needed. Most numerical methods diffuse the interface, resulting in artificial mixing and spurious reactions. In this paper, we propose a numerical method that mitigates this issue. We present methods for passive and active scalars, and demonstrate their effectiveness with several examples.
Recent progress in the joint velocity-scalar PDF method
Anand, M. S.
1995-01-01
This viewgraph presentation discusses joint velocity-scalar PDF method; turbulent combustion modeling issues for gas turbine combustors; PDF calculations for a recirculating flow; stochastic dissipation model; joint PDF calculations for swirling flows; spray calculations; reduced kinetics/manifold methods; parallel processing; and joint PDF focus areas.
Asymmetric inelastic inert doublet dark matter from triplet scalar leptogenesis
Energy Technology Data Exchange (ETDEWEB)
Arina, Chiara, E-mail: chiara.arina@physik.rwth-aachen.de [Institut fuer Theoretische Teilchenphysik und Kosmologie, RWTH Aachen, 52056 Aachen (Germany); Sahu, Narendra, E-mail: Narendra.Sahu@ulb.ac.be [Service de Physique Theorique, Universite Libre de Bruxelles, CP225, Bld du Triomphe, 1050 Brussels (Belgium)
2012-01-21
The nature of dark matter (DM) particles and the mechanism that provides their measured relic abundance are currently unknown. In this paper we investigate inert scalar and vector like fermion doublet DM candidates with a charge asymmetry in the dark sector, which is generated by the same mechanism that provides the baryon asymmetry, namely baryogenesis-via-leptogenesis induced by decays of scalar triplets. At the same time the model gives rise to neutrino masses in the ballpark of oscillation experiments via type II seesaw. We discuss possible sources of depletion of asymmetry in the DM and visible sectors and solve the relevant Boltzmann equations for quasi-equilibrium decay of triplet scalars. A Monte-Carlo-Markov-Chain analysis is performed for the whole parameter space. The survival of the asymmetry in the dark sector leads to inelastic scattering off nuclei. We then apply Bayesian statistic to infer the model parameters favoured by the current experimental data, in particular the DAMA annual modulation and XENON100 exclusion limit. The latter strongly disfavours asymmetric scalar doublet DM of mass O(TeV) as required by DM-DM-bar oscillations, while an asymmetric vector like fermion doublet DM with mass around 100 GeV is a good candidate for DAMA annual modulation yet satisfying the constraints from XENON100 data.
Unifying darko-lepto-genesis with scalar triplet inflation
Energy Technology Data Exchange (ETDEWEB)
Arina, Chiara, E-mail: chiara.arina@physik.rwth-aachen.de [Institut fuer Theoretische Teilchenphysik und Kosmologie, RWTH Aachen, 52056 Aachen (Germany); Gong, Jinn-Ouk, E-mail: jinn-ouk.gong@cern.ch [Theory Division, CERN, CH-1211 Geneve 23 (Switzerland); Sahu, Narendra, E-mail: nsahu@iith.ac.in [Department of Physics, IIT Hyderabad, Yeddumailaram 502 205, Andhra Pradesh (India)
2012-12-21
We present a scalar triplet extension of the standard model to unify the origin of inflation with neutrino mass, asymmetric dark matter and leptogenesis. In presence of non-minimal couplings to gravity the scalar triplet, mixed with the standard model Higgs, plays the role of inflaton in the early Universe, while its decay to SM Higgs, lepton and dark matter simultaneously generate an asymmetry in the visible and dark matter sectors. On the other hand, in the low energy effective theory the induced vacuum expectation value of the triplet gives sub-eV Majorana masses to active neutrinos. We investigate the model parameter space leading to successful inflation as well as the observed dark matter to baryon abundance. Assuming the standard model like Higgs mass to be at 125-126 GeV, we found that the mass scale of the scalar triplet to be Less-Than-Or-Equivalent-To O(10{sup 9}) GeV and its trilinear coupling to doublet Higgs is Less-Than-Or-Equivalent-To 0.09 so that it not only evades the possibility of having a metastable vacuum in the standard model, but also lead to a rich phenomenological consequences as stated above. Moreover, we found that the scalar triplet inflation strongly constrains the quartic couplings, while allowing for a wide range of Yukawa couplings which generate the CP asymmetries in the visible and dark matter sectors.
Growth of spherical overdensities in scalar-tensor cosmologies
Nazari-Pooya, N; Pace, F; Jassur, D Mohammad-Zadeh
2016-01-01
The accelerated expansion of the universe is a rather established fact in cosmology and many different models have been proposed as a viable explanation. Many of these models are based on the standard general relativistic framework of non-interacting fluids or more recently of coupled (interacting) dark energy models, where dark energy (the scalar field) is coupled to the dark matter component giving rise to a fifth-force. An interesting alternative is to couple the scalar field directly to the gravity sector via the Ricci scalar. These models are dubbed non-minimally coupled models and give rise to a time-dependent gravitational constant. In this work we study few models falling into this category and describe how observables depend on the strength of the coupling. We extend recent work on the subject by taking into account also the effects of the perturbations of the scalar field and showing their relative importance on the evolution of the mass function. By working in the framework of the spherical collaps...
Cosmological Evolution of Statistical System of Scalar Charged Particles
Ignat'ev, Yurii; Mikhailov, Mikhail; Ignatyev, Dmitry
2014-01-01
In the paper we consider the macroscopic model of plasma of scalar charged particles, obtained by means of the statistical averaging of the microscopic equations of particle dynamics in a scalar field. On the basis of kinetic equations, obtained from averaging, and their strict integral consequences, a self-consistent set of equations is formulated which describes the self-gravitating plasma of scalar charged particles. It was obtained the corresponding closed cosmological model which also was numerically simulated for the case of one-component degenerated Fermi gas and two-component Boltzmann system. It was shown that results depend weakly on the choice of a statistical model. Two specific features of cosmological evolution of a statistical system of scalar charged particles were obtained with respect to cosmological evolution of the minimal interaction models: appearance of giant bursts of invariant cosmological acceleration $\\Omega$ at the time interval $8\\cdot10^3\\div2\\cdot10^4 t_{Pl}$ and strong heating ...
Vacuum stability and perturbativity of SU(3) scalars
Heikinheimo, Matti; Kannike, Kristjan; Lyonnet, Florian; Raidal, Martti; Tuominen, Kimmo; Veermäe, Hardi
2017-10-01
We calculate the vacuum stability conditions and renormalisation group equations for the extensions of standard model with a higher colour multiplet scalar up to the representation 15' that leaves the strong interaction asymptotically free. In order to find the vacuum stability conditions, we calculate the orbit spaces for the self-couplings of the higher multiplets, which for the representations 15 and 15' of SU(3) c are highly complicated. However, if the scalar potential is linear in orbit space variables, it is sufficient to know the convex hull of the orbit space. Knowledge of the orbit spaces also facilitates the minimisation of the potentials. In contrast to the self-couplings of other multiplets, we find that the scalar quartic couplings of the representations 3 and 8 walk rather than run, remaining nearly constant and perturbative over a vast energy range. We describe the conditions for walking couplings using a schematic model. With these technical results at hand we revise earlier results of generation of new scales with large SU(3) c scalar multiplets. Our results are easily extendable to models of new physics with additional SU(3) or SU( N) gauge symmetries.
Polchinski ERG Equation in O(N) Scalar Field Theory
Kubyshin, Yuri; Neves, Rui; Potting, Robertus
We investigate the Polchinski ERG equation for d-dimensional O(N) scalar field theory. In the context of the non-pertubative derivative expansion we find families of regular solutions and establish their relation with the physical fixed points of the theory. Special emphasis is given to the limit N=∞ for which many properties can be studied analytically.
Polchinski ERG Equation in O(N) Scalar Field Theory
Kubyshin, Yuri; Neves, Rui; Potting, Robertus
2001-01-01
We investigate the Polchinski ERG equation for d-dimensional O(N) scalar field theory. In the context of the non-perturbative derivative expansion we find families of regular solutions and establish their relation with the physical fixed points of the theory. Special emphasis is given to the large N limit for which many properties can be studied analytically.
Direct Searches for Scalar Leptoquarks at the Run II Tevatron
Energy Technology Data Exchange (ETDEWEB)
Ryan, Daniel Edward [Tufts Univ., Medford, MA (United States)
2004-08-01
This dissertation sets new limits on the mass of the scalar leptoquark from direct searches carried out at the Run II CDF detector using data from March 2001 to October 2003. The data analyzed has a total time-integrated measured luminosity of 198 pb^{-1} of p$\\bar{p}$ collisions with √s = 1.96 TeV. Leptoquarks are assumed to be pair-produced and to decay into a lepton and a quark of the same generation. They consider two possible leptoquark decays: (1) β = BR(LQ → μq) = 1.0, and (2) β = BR(LQ → μq) = 0.5. For the β = 1 channel, they focus on the signature represented by two isolated high-p_{T} muons and two isolated high-p_{T} jets. For the β = 1/2 channel, they focus on the signature represented by one isolated high-p_{T} muon, large missing transverse energy, and two isolated high-p_{T} jets. No leptoquark signal is experimentally detected for either signature. Using the next to leading order theoretical cross section for scalar leptoquark production in p$\\bar{p}$ collisions [1], they set new mass limits on second generation scalar leptoquarks. They exclude the existence of second generation scalar leptoquarks with masses below 221(175) GeV/c^{2} for the β = 1(1/2) channels.
Scalar wave scattering from Schwarzschild black holes in modified gravity
Sibandze, Dan B; Maharaj, Sunil D; Nzioki, Anne Marie; Dunsby, Peter K S
2016-01-01
We consider the scattering of gravitational waves off a Schwarzschild Black Hole in $f(R)$ gravity. We find that, while the reflection and transmission coefficients for tensor waves are the same as in General Relativity, a larger fraction of scalar waves are reflected compared to what one obtains for tensors. This may provide a novel observational signature for fourth order gravity.
Eigenvalue Problem of Scalar Fields in BTZ Black Hole Spacetime
Kuwata, Maiko; Kenmoku, Masakatsu; Shigemoto, Kazuyasu
2008-01-01
We studied the eigenvalue problem of scalar fields in the (2+1)-dimensional BTZ black hole spacetime. The Dirichlet boundary condition at infinity and the Dirichlet or the Neumann boundary condition at the horizon are imposed. Eigenvalues for normal modes are characterized by the principal quantum number $(0
Anisotropic cosmological models and generalized scalar tensor theory
Indian Academy of Sciences (India)
Abstract. In this paper generalized scalar tensor theory has been considered in the background of anisotropic cosmological models, namely, axially symmetric Bianchi-I, Bianchi-III and Kortowski–. Sachs space-time. For bulk viscous fluid, both exponential and power-law solutions have been stud- ied and some assumptions ...
Effective action for a quantum scalar field in warped spaces
Energy Technology Data Exchange (ETDEWEB)
Hoff da Silva, J.M.; Mendonca, E.L.; Scatena, E. [Universidade Estadual Paulista ' ' Julio de Mesquita Filho' ' -UNESP, Departamento de Fisica e Quimica, Guaratingueta, SP (Brazil)
2015-11-15
We investigate the one-loop corrections, at zero as well as finite temperature, of a scalar field taking place in a braneworld motivated warped background. After to reach a well-defined problem, we calculate the effective action with the corresponding quantum corrections to each case. (orig.)
Real gauge singlet scalar extension of the Standard Model: A ...
Indian Academy of Sciences (India)
... the WMAP limit and the experimental results considered here. The possible differential direct detection rates and annual variation of total detection rates have been estimated for this scalar DM candidate for two detector materials, namely Ge and Xe. Finally, the -ray flux has been calculated from the galactic centre due ...
Searches for Light Scalars, Pseudoscalars, and Gauge Bosons
Soffer, Abner
2015-01-01
In the past few years there has been a great deal of theoretical and experimental activity related to the search for low-mass scalars, pseudoscalars, and vectors in various scenarios of physics beyond the standard model. I review the current status of this topic, focusing on results obtained since FPCP 2014.
Subfilter scalar-flux vector orientation in homogeneous isotropic turbulence.
Verma, Siddhartha; Blanquart, G
2014-06-01
The geometric orientation of the subfilter-scale scalar-flux vector is examined in homogeneous isotropic turbulence. Vector orientation is determined using the eigenframe of the resolved strain-rate tensor. The Schmidt number is kept sufficiently large so as to leave the velocity field, and hence the strain-rate tensor, unaltered by filtering in the viscous-convective subrange. Strong preferential alignment is observed for the case of Gaussian and box filters, whereas the sharp-spectral filter leads to close to a random orientation. The orientation angle obtained with the Gaussian and box filters is largely independent of the filter width and the Schmidt number. It is shown that the alignment direction observed numerically using these two filters is predicted very well by the tensor-diffusivity model. Moreover, preferred alignment of the scalar gradient vector in the eigenframe is shown to mitigate any probable issues of negative diffusivity in the tensor-diffusivity model. Consequentially, the model might not suffer from solution instability when used for large eddy simulations of scalar transport in homogeneous isotropic turbulence. Further a priori tests indicate poor alignment of the Smagorinsky and stretched vortex model predictions with the exact subfilter flux. Finally, strong filter dependence of subfilter scalar-flux orientation suggests that explicit filtering may be preferable to implicit filtering in large eddy simulations.
Study of systematic errors on the scalar boson mass
Randle-Conde, Aidan
2015-01-01
In this talk I presented studies of the scalar boson mass resolution at the LHC. I described in detail the limiting factors on resolution, the methods used to determine the mass resolution, and the statistical sample size required for these results for the ZZ* and diphoton final states. I finished the talk by comparing projections for various linear collider scenarios.
Accelerating Universe and the Scalar-Tensor Theory
Directory of Open Access Journals (Sweden)
Yasunori Fujii
2012-10-01
Full Text Available To understand the accelerating universe discovered observationally in 1998, we develop the scalar-tensor theory of gravitation originally due to Jordan, extended only minimally. The unique role of the conformal transformation and frames is discussed particularly from a physical point of view. We show the theory to provide us with a simple and natural way of understanding the core of the measurements, Λobs ∼ t0−2 for the observed values of the cosmological constant and today’s age of the universe both expressed in the Planckian units. According to this scenario of a decaying cosmological constant, Λobs is this small only because we are old, not because we fine-tune the parameters. It also follows that the scalar field is simply the pseudo Nambu–Goldstone boson of broken global scale invariance, based on the way astronomers and astrophysicists measure the expansion of the universe in reference to the microscopic length units. A rather phenomenological trapping mechanism is assumed for the scalar field around the epoch of mini-inflation as observed, still maintaining the unmistakable behavior of the scenario stated above. Experimental searches for the scalar field, as light as ∼ 10−9 eV, as part of the dark energy, are also discussed.
Galileons as the Scalar Analogue of General Relativity
Klein, Remko; Ozkan, Mehmet; Roest, Diederik
2016-01-01
We establish a correspondence between general relativity with diffeomorphism invariance and scalar field theories with Galilean invariance: notions such as the Levi-Civita connection and the Riemann tensor have a Galilean counterpart. This suggests Galilean theories as the unique nontrivial
Long-lived colored scalars at the LHC
Energy Technology Data Exchange (ETDEWEB)
De la Puente, Alejandro [Carleton University, Department of Physics, Ottawa, ON (Canada); TRIUMF, Theory Department, Vancouver, BC (Canada); Szynkman, Alejandro [Universidad Nacional de La Plata, IFLP, CONICET-Dept. de Fisica, La Plata (Argentina)
2016-03-15
We study the collider signatures of a long-lived massive colored scalar transforming trivially under the weak interaction and decaying within the inner sections of a detector such as ATLAS or CMS. In our study, we assume that the colored scalar couples at tree-level to a top quark and a stable fermion, possibly arising from a dark sector or from supersymmetric extensions of the Standard Model. After implementing the latest experimental searches for long-lived colored scalars, we observe a region of parameter space consistent with a colored electroweak-singlet scalar with mass between ∝200-350 GeV and a lifetime between 0.1-1mm/c together, with a nearly degenerate dark fermion that may be probed at the √(s) = 13 TeV LHC. We show that a search strategy using a combination of cuts on missing transverse energy and impact parameters can exclude regions of parameter space not accessed by prompt searches. We show that a region of parameter space within our simplified model may naturally arise from the light-stop window regime of supersymmetric extensions of the Standard Model, where a light mostly right-handed stop has a mass slightly larger than the lightest neutralino and decays through a four-body process. (orig.)
A comparative study between all-electron scalar relativistic ...
Indian Academy of Sciences (India)
effect on the adsorption behaviour of other small molecules onto gold clusters are necessary in the future. Keywords. Small gold cluster; hydrogen molecule; adsorption; scalar relativistic effect. 1. Introduction. Small gold clusters have attracted much attention from both industrial and scientific areas due to their unique.
Classification of scalar and dyadic nonlocal optical response models
DEFF Research Database (Denmark)
Wubs, Martijn
2015-01-01
Nonlocal optical response is one of the emerging effects on the nanoscale for particles made of metals or doped semiconductors. Here we classify and compare both scalar and tensorial nonlocal response models. In the latter case the nonlocality can stem from either the longitudinal response...
Scalar sector of two-Higgs-doublet models: A minireview
Indian Academy of Sciences (India)
Now that a 125 GeV scalar resonance has been discovered at the LHC, with its couplings to other particles showing increasing affinity to the Standard Model Higgs-like behaviour, the 2HDM parameter space is more squeezed than ever. We briefly review the different parametrizations of the 2HDM potential and discuss the ...
Probing Scalar Couplings Through Tests Of The Equivalence Principle
Chen, J
2005-01-01
It could be that our universe contains one or more nearly-massless neutral scalars, either as low energy relics of the UV complete theory, or as dynamical dark energy as called upon by observations. Here we discuss phenomenological ramifications of the coupling of a light scalar to the Standard Model. More precisely, we argue that low energy effects of this scalar are dominated by its linear couplings to gauge field kinetic terms and to fermion mass terms, which could then source fifth forces and induce variations in the 'constants.' We determine the limits on each of these couplings, first by determining the strength of the source from each sector. We find that couplings to the gluon kinetic term and to the strange quark mass term are most constrained by current null results for long range composition dependent fifth forces. Should such as detection occur, it would most likely arise from couplings to these sectors. If we are fortunate enough to make multiple measurements of scalar forces with test body pairs...
Small visible energy scalar top iterative discriminant analysis
Indian Academy of Sciences (India)
2015-11-27
Nov 27, 2015 ... Light scalar top quarks with a small mass difference with respect to the neutralino mass are of particular cosmological interest. This study uses an iterative discriminant analysis method to optimize the expected selection efficiency at the international linear collider (ILC).
f(R) gravity: scalar perturbations in the late Universe
Czech Academy of Sciences Publication Activity Database
Eingorn, M.; Novák, Jan; Zhuk, A.
2014-01-01
Roč. 74, č. 8 (2014), s. 3005 ISSN 1434-6044 Institutional support: RVO:67985840 Keywords : nonlinear f(R) gravity * scalar cosmological perturbations * scalaron Subject RIV: BA - General Mathematics Impact factor: 5.084, year: 2014 http://link.springer.com/article/10.1140/epjc/s10052-014-3005-1
A quasifibration of spaces of positive scalar curvature metrics
Chernysh, Vladislav
2004-01-01
In this paper we show that for Riemannian manifolds with boundary the natural restriction map is a quasifibration between spaces of metrics of positive scalar curvature. We apply this result to study homotopy properties of spaces of such metrics on manifolds with boundary.
Two loop stress-energy tensor for inflationary scalar electrodynamics
Prokopec, T.; Tsamis, N.C.; Woodard, R.P.
2008-01-01
We calculate the expectation value of the coincident product of two field strength tensors at two loop order in scalar electrodynamics on de Sitter background. The result agrees with the stochastic formulation which we have developed in a companion paper [2] for the nonperturbative resummation of
Factorization for radiative heavy quarkonium decays into scalar Glueball
Energy Technology Data Exchange (ETDEWEB)
Zhu, Ruilin [INPAC, Shanghai Key Laboratory for Particle Physics and Cosmology,Department of Physics and Astronomy, Shanghai Jiao Tong University,Dongchuan RD 800, Shanghai 200240 (China); State Key Laboratory of Theoretical Physics,Institute of Theoretical Physics, Chinese Academy of Sciences,Zhongguancun E. St. 55, Beijing 100190 (China); CAS Center for Excellence in Particle Physics,Institute of High Energy Physics, Chinese Academy of Sciences,Yuquan RD 19B, Beijing 100049 (China)
2015-09-24
We establish the factorization formula for scalar Glueball production through radiative decays of vector states of heavy quarkonia, e.g. J/ψ, ψ(2S) and Υ(nS), where the Glueball mass is much less than the parent heavy quarkonium mass. The factorization is demonstrated explicitly at one-loop level through the next-to-leading order (NLO) corrections to the hard kernel, the non-relativistic QCD (NRQCD) long-distance matrix elements (LDMEs) of the heavy quarkonium, and the light-cone distribution amplitude (LCDA) of scalar Glueball. The factorization provides a comprehensive theoretical approach to investigate Glueball production in the radiative decays of vector states of heavy quarkonia and determine the physic nature of Glueball. We discuss the scale evolution equation of LCDA for scalar Glueball. In the end, we extract the value of the decay constant of Scalar Glueball from Lattice QCD calculation and analyze the mixing effect among f{sub 0}(1370), f{sub 0}(1500) and f{sub 0}(1710).
Certified quantum non-demolition measurement of atomic spins
Sewell, Robert; Napolitano, Mario; Behbood, Naeimeh; Colangelo, Giorgio; Martin Ciurana, Ferran; Mitchell, Morgan
2014-05-01
We report certified quantum non-demolition (QND) measurement of atomic spins via paramagnetic Faraday rotation, recently used to demonstrate spin squeezing in an optical magnetometer [Phys. Rev. Lett. 109, 253605 (2012)]. We apply rigorous criteria, originally developed for continuous variable experiments in optics [Nature 396, 537 (1998)] and which we have extended to describe measurements of material systems [New J. Phys. 14, 085021 (2012)], to distinguish QND from similar non-classical measurements. We observe quantum state preparation (QSP) and information-damage trade-off (IDT) beyond their classical limits by seven and twelve standard deviations, respectively [Nat. Phot. 7, 517 (2013)].
A Class of Homogeneous Scalar Tensor Cosmologies with a Radiation Fluid
Yazadjiev, Stoytcho S.
We present a new class of exact homogeneous cosmological solutions with a radiation fluid for all scalar tensor theories. The solutions belong to Bianchi type VIh cosmologies. Explicit examples of nonsingular homogeneous scalar tensor cosmologies are also given.
The subgrid-scale scalar variance under supercritical pressure conditions
Masi, Enrica; Bellan, Josette
2011-08-01
To model the subgrid-scale (SGS) scalar variance under supercritical-pressure conditions, an equation is first derived for it. This equation is considerably more complex than its equivalent for atmospheric-pressure conditions. Using a previously created direct numerical simulation (DNS) database of transitional states obtained for binary-species systems in the context of temporal mixing layers, the activity of terms in this equation is evaluated, and it is found that some of these new terms have magnitude comparable to that of governing terms in the classical equation. Most prominent among these new terms are those expressing the variation of diffusivity with thermodynamic variables and Soret terms having dissipative effects. Since models are not available for these new terms that would enable solving the SGS scalar variance equation, the adopted strategy is to directly model the SGS scalar variance. Two models are investigated for this quantity, both developed in the context of compressible flows. The first one is based on an approximate deconvolution approach and the second one is a gradient-like model which relies on a dynamic procedure using the Leonard term expansion. Both models are successful in reproducing the SGS scalar variance extracted from the filtered DNS database, and moreover, when used in the framework of a probability density function (PDF) approach in conjunction with the β-PDF, they excellently reproduce a filtered quantity which is a function of the scalar. For the dynamic model, the proportionality coefficient spans a small range of values through the layer cross-stream coordinate, boding well for the stability of large eddy simulations using this model.
IceBridge Geometrics 823A Cesium Magnetometer L1B Time-Tagged Magnetic Field, Version 1
National Aeronautics and Space Administration — The NASA IceBridge Geometrics 823A Cesium Magnetometer L1B Time-Tagged Magnetic Field (IMGEO1B) data set contains magnetic field strength measurements taken over...
Mixed Inert scalar triplet dark matter, radiative neutrino masses and leptogenesis
Lu, Wen-Bin; Gu, Pei-Hong
2017-01-01
The neutral component of an inert scalar multiplet with hypercharge can provide a stable dark matter particle when its real and imaginary parts have a splitting mass spectrum. Otherwise, a tree-level dark-matter-nucleon scattering mediated by the Z boson will be much above the experimental limit. In this paper we focus on a mixed inert scalar triplet dark matter scenario where a complex scalar triplet with hypercharge can mix with another real scalar triplet without hypercharge through their ...
Directory of Open Access Journals (Sweden)
Henry S.
2014-01-01
Full Text Available Groundwater can influence the geomagnetic field measured underground in at least two key ways. The water levels in rock will determine its electrical conductivity, and thus change the magnitude of the telluric currents induced in the rock by changing magnetic fields generated in the ionosphere. This can be studied by using multiple magnetometers at different underground locations. Secondly the flow of water through rock will generate a small magnetic signal, of unknown magnitude, through the electrokinetic effect. SQUID magnetometry has the potential to allow passive studies of groundwater changes in complex systems such as karst. We have monitored geomagnetic signals using two SQUID magnetometers at the LSBB underground laboratory, and set an initial limit on the magnitude of the electrokinetic signal. We now plan to carry out a longer term measurement using three SQUID systems as well as fluxgate sensors to track changes in the gradient of the magnetic field across the underground complex.
New type of fluxgate magnetometer for the heart’s magnetic fields detection
Directory of Open Access Journals (Sweden)
Rybalko Ruslan
2015-09-01
Full Text Available The application area of fluxgate sensors is limited by their sensitivity. Medical researches create high demand on the magnetometers with the characteristics of high accuracy and sensibility for measuring weak magnetic fields produced by the human body, such as the heart‘s magnetic field. Due to the insufficient sensitivity of fluxgate sensors, superconducting magnetometers (SQUID take the dominant position for the cardiomagnetic measurements. They have to be cooled by liquefied gases and it leads to high service costs. Therefore an idea of creating a high sensitive sensor based on fluxgate principles and known methods of measurement is attractive and up to date. This paper is dedicated to the modified flux-gate sensors based on Racetrack technology with a new approach of signal demodulation. The improved fluxgate sensor system provides detection of the heart‘s magnetic field without additional expenditures for use.
On-orbit real-time magnetometer bias determination for micro-satellites without attitude information
Directory of Open Access Journals (Sweden)
Zhang Zhen
2015-10-01
Full Text Available Due to the disadvantages such as complex calculation, low accuracy of estimation, and being non real time in present methods, a new real-time algorithm is developed for on-orbit magnetometer bias determination of micro-satellites without attitude knowledge in this paper. This method uses the differential value approach. It avoids the impact of quartic nature and uses the iterative method to satisfy real-time applications. Simulation results indicate that the new real-time algorithm is more accurate compared with other methods, which are also tested by an experiment system using real noise data. With the new real-time algorithm, a magnetometer calibration can be taken on-orbit and will reduce the demand for computing power effectively.
Micromechanical ``Trampoline'' Magnetometers for Use in Pulsed Magnetic Fields Exceeding 60 Tesla
Balakirev, F. F.; Boebinger, G. S.; Aksyuk, V.; Gammel, P. L.; Haddon, R. C.; Bishop, D. J.
1998-03-01
We present the design, construction, and operation of a novel magnetometer for use in intense pulsed magnetic fields. The magnetometer consists of a silicon micromachined "trampoline" to which the sample is attached. The small size of the device (typically 400 microns on a side) gives a fast mechanical response (10,000 to 50,000 Hz) and extremely high sensitivity (10-11 Am^2, corresponding to 10-13 Am^2/Hz^(1/2)). The device is robust against electrical and mechanical noise and requires no special vibration isolation from the pulsed magnet. As a demonstration, we present data taken in a 60 tesla pulsed magnetic field which show clear de Haas-van Alphen oscillations in a one microgram sample of the organic superconductor K-(BEDT-TTF)_2Cu(NCS)_2.
Teixeira, J M; Lusche, R; Ventura, J; Fermento, R; Carpinteiro, F; Araujo, J P; Sousa, J B; Cardoso, S; Freitas, P P
2011-04-01
Magneto-optical Kerr effect (MOKE) magnetometry is an indispensable, reliable, and one of the most widely used techniques for the characterization of nanostructured magnetic materials. Information, such as the magnitude of coercive fields or anisotropy strengths, can be readily obtained from MOKE measurements. We present a description of our state-of-the-art vectorial MOKE magnetometer, being an extremely versatile, accurate, and sensitivity unit with a low cost and comparatively simple setup. The unit includes focusing lenses and an automatized stepper motor stage for angular dependent measurements. The performance of the magnetometer is demonstrated by hysteresis loops of Co thin films displaying uniaxial anisotropy induced on growth, MnIr/CoFe structures exhibiting the so called exchange bias effect, spin valves, and microfabricated flux guides produced by optical lithography. © 2011 American Institute of Physics
Feasibility study of a sup 3 He-magnetometer for neutron electric dipole moment experiments
Borisov, Y; Leduc, M; Lobashev, V; Otten, E W; Sobolev, Y
2000-01-01
We report on a sup 3 He-magnetometer capable of detecting tiny magnetic field fluctuations of less than 10 sup - sup 1 sup 4 T in experiments for measuring the electric dipole moment (EDM) of the neutron. It is based on the Ramsey technique of separated oscillating fields and uses nuclear spin-polarized sup 3 He gas which is stored in two vessels of V approx =10 l in a sandwich-type arrangement around the storage bottle for ultra-cold neutrons (UCN). The gas is polarized by means of optical pumping in a separate, small discharge cell at pressures around 0.5 mbar and is then expanded into the actual magnetometer volume. To detect the polarization of sup 3 He gas at the end of the storage cycle the gas is pumped out by means of an oil-diffusion pump and compressed again into the discharge cell where optical detection of nuclear polarization is used.
Magnetocardiography measurements with 4He vector optically pumped magnetometers at room temperature
Morales, S.; Corsi, M. C.; Fourcault, W.; Bertrand, F.; Cauffet, G.; Gobbo, C.; Alcouffe, F.; Lenouvel, F.; Le Prado, M.; Berger, F.; Vanzetto, G.; Labyt, E.
2017-09-01
In this paper, we present a proof of concept study which demonstrates for the first time the possibility of recording magnetocardiography (MCG) signals with 4He vector optically pumped magnetometers (OPM) operated in a gradiometer mode. Resulting from a compromise between sensitivity, size and operability in a clinical environment, the developed magnetometers are based on the parametric resonance of helium in a zero magnetic field. Sensors are operated at room temperature and provide a tri-axis vector measurement of the magnetic field. Measured sensitivity is around 210 f T (√Hz)-1 in the bandwidth (2 Hz; 300 Hz). MCG signals from a phantom and two healthy subjects are successfully recorded. Human MCG data obtained with the OPMs are compared to reference electrocardiogram recordings: similar heart rates, shapes of the main patterns of the cardiac cycle (P/T waves, QRS complex) and QRS widths are obtained with both techniques.
Martynov, M. V.; Smirnov, A. D.
2010-07-01
The production of pairs of scalar particles belonging to an arbitrary color multiplet of the SU c (3) group in proton-proton collisions is considered, and the differential and total cross sections for the corresponding partonic processes are obtained. The total cross section for the production of octets of scalar gluons F 1 and F 2 at LHC is calculated versus their mass, and their dominant decays, which are necessary for their searches, are discussed. It is shown that, for mF 1 ≲ 1000 GeV, the number of signal ttilde tbtilde b events fromthe decays of the scalar gluon F 1 may exceed substantially (by not less than three standard deviations) the Standart Model background and that the cross section for the production of scalar gluons F 1 and F 2 having masses in the region m F1, m F2 ≲ 1300 GeV may be sufficient for the efficient ( N events ≲ 100-1000 at L = 10-100 fb-1) production of these particles at LHC.
Search for scalar top quarks decaying into scalar tau leptons with ATLAS at sqrt{s} =8 TeV
AUTHOR|(INSPIRE)INSPIRE-00358725; Colijn, Auke Pieter
2017-10-06
This thesis presents a search for Supersymmetry carried out in a particular scenario arising from the Gauge Mediated Supersymmetry breaking mechanism that assumes a massless gravitino as lightest supersymmetric particle, a scalar tau lepton as next-to-lightest supersymmetric particle and the top squark as the lightest among the quark superpartners. The analysis is performed using the data collected by ATLAS at a centre-of-mass energy √s = 8 TeV during 2012 data taking, for a total of 20.3 fb−1 of integrated luminosity of proton-proton collisions. Scalar top quark candidates are searched for in events with either two light leptons, one hadronically decaying tau and one light lepton or two hadronically decaying taus in the final state. No significant excess over the Standard Model expectation is found and the results are interpreted as 95% confidence lower limits not top squark and scalar tau masses. Depending on the scalar tau mass, lower limits between 490 and 650 GeV are placed on the top squark mass wit...
Energy Technology Data Exchange (ETDEWEB)
Dolgovskiy, V. [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Lebedev, V., E-mail: victor.lebedev@unifr.ch [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Colombo, S.; Weis, A. [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Michen, B.; Ackermann-Hirschi, L. [Adolphe Merkle Institute, University of Fribourg, CH-1700 Fribourg (Switzerland); Petri-Fink, A. [Adolphe Merkle Institute, University of Fribourg, CH-1700 Fribourg (Switzerland); Chemistry Department, University of Fribourg, CH-1700 Fribourg (Switzerland)
2015-04-01
The discrimination of immobilised superparamagnetic iron oxide nanoparticles (SPIONs) against SPIONs in fluid environments via their magnetic relaxation behaviour is a powerful tool for bio-medical imaging. Here we demonstrate that a gradiometer of laser-pumped atomic magnetometers can be used to record accurate time series of the relaxing magnetic field produced by pre-polarised SPIONs. We have investigated dry in vitro maghemite nanoparticle samples with different size distributions (average radii ranging from 14 to 21 nm) and analysed their relaxation using the Néel–Brown formalism. Fitting our model function to the magnetorelaxation (MRX) data allows us to extract the anisotropy constant K and the saturation magnetisation M{sub S} of each sample. While the latter was found not to depend on the particle size, we observe that K is inversely proportional to the (time- and size-) averaged volume of the magnetised particle fraction. We have identified the range of SPION sizes that are best suited for MRX detection considering our specific experimental conditions and sample preparation technique. - Highlights: • We studied magnetorelaxation of magnetic nanoparticles using atomic magnetometers. • We show that atomic magnetometers yield high precision MRX data. • The observed magnetorelaxation is well described by the moment superposition model. • Model fits allow extraction of nanoparticle material parameters of six samples. • All samples exhibit an unexpected size-dependent anisotropy constant.
Identification of Mobile Phones Using the Built-In Magnetometers Stimulated by Motion Patterns.
Baldini, Gianmarco; Dimc, Franc; Kamnik, Roman; Steri, Gary; Giuliani, Raimondo; Gentile, Claudio
2017-04-06
We investigate the identification of mobile phones through their built-in magnetometers. These electronic components have started to be widely deployed in mass market phones in recent years, and they can be exploited to uniquely identify mobile phones due their physical differences, which appear in the digital output generated by them. This is similar to approaches reported in the literature for other components of the mobile phone, including the digital camera, the microphones or their RF transmission components. In this paper, the identification is performed through an inexpensive device made up of a platform that rotates the mobile phone under test and a fixed magnet positioned on the edge of the rotating platform. When the mobile phone passes in front of the fixed magnet, the built-in magnetometer is stimulated, and its digital output is recorded and analyzed. For each mobile phone, the experiment is repeated over six different days to ensure consistency in the results. A total of 10 phones of different brands and models or of the same model were used in our experiment. The digital output from the magnetometers is synchronized and correlated, and statistical features are extracted to generate a fingerprint of the built-in magnetometer and, consequently, of the mobile phone. A SVM machine learning algorithm is used to classify the mobile phones on the basis of the extracted statistical features. Our results show that inter-model classification (i.e., different models and brands classification) is possible with great accuracy, but intra-model (i.e., phones with different serial numbers and same model) classification is more challenging, the resulting accuracy being just slightly above random choice.
Directory of Open Access Journals (Sweden)
Baptiste Delporte
2012-03-01
Full Text Available In this paper, we propose two methods based on quaternions to compute the angles of inclination and the angular velocity with 6 degrees of freedom using the measurements of a 3-axis accelerometer and a 3-axis magnetometer. Each method has singularities which occur during the computation of the orientation of the device in the 3-dimensional space. We propose solutions to avoid these singularities. Experimental results are given to compare our model with a real gyroscope.
Magnetometer instrument team studies for the definition phase of the outer planets grand tour
Coleman, P. J., Jr.
1973-01-01
The work performed by the magnetic fields investigation team during the mission definition phases of the Outer Planets Grand Tour (OPGT) and the Mariner Jupiter Saturn (MJS) Missions is reported. This work involved three tasks: (1) defining the objectives of the magnetic fields investigations, (2) defining the magnetometer systems required to meet these objectives, and (3) developing and testing hardware elements in certain mission-specific areas.
Directory of Open Access Journals (Sweden)
Sapunov V.A., Rasson J., Sergeev A.V., Narkhov E.D., Denisov A.Y., Rubinstein B.Y., Sapunov A.V.
2016-12-01
Full Text Available This article provides suggestions and ideas on the use of magnetic observatories to observe the stability of the gyromagnetic ratio of the proton and the electron in order to detect the effects of new fundamental physics and cosmology. The idea consist in long continuous recording of the signals Overhauser and optical pumping K magnetometers. Such systems can be highly effective network for forecasting earthquakes due to highest long term sensitivity.
Reduction of the Bethe–Salpeter wave function: Fermion–scalar ...
Indian Academy of Sciences (India)
2School of Physics and Information Science, Shanxi Normal University, Linfen 041004, China. ∗. Corresponding ... Introduction. Supersymmetry theories predict the existence of massive scalar quarks and scalar leptons, and there are possibilities for these scalar particles to form bound states with ordinary particles or with ...
Attitude Determination with Magnetometers and Accelerometers to Use in Satellite Simulator
Directory of Open Access Journals (Sweden)
Helio Koiti Kuga
2013-01-01
Full Text Available Attitude control of artificial satellites is dependent on information provided by its attitude determination process. This paper presents the implementation and tests of a fully self-contained algorithm for the attitude determination using magnetometers and accelerometers, for application on a satellite simulator based on frictionless air bearing tables. However, it is known that magnetometers and accelerometers need to be calibrated so as to allow that measurements are used to their ultimate accuracy. A calibration method is implemented which proves to be essential for improving attitude determination accuracy. For the stepwise real-time attitude determination, it was used the well-known QUEST algorithm which yields quick response with reduced computer resources. The algorithms are tested and qualified with actual data collected on the streets under controlled situations. For such street runaways, the experiment employs a solid-state magnetoresistive magnetometer and an IMU navigation block consisting of triads of accelerometers and gyros, with MEMS technology. A GPS receiver is used to record positional information. The collected measurements are processed through the developed algorithms, and comparisons are made for attitude determination using calibrated and noncalibrated data. The results show that the attitude accuracy reaches the requirements for real-time operation for satellite simulator platforms.
An Optically Pumped Magnetometer Working in the Light-Shift Dispersed Mz Mode.
Schultze, Volkmar; Schillig, Bastian; IJsselsteijn, Rob; Scholtes, Theo; Woetzel, Stefan; Stolz, Ronny
2017-03-10
We present an optically pumped magnetometer working in a new operational mode-the light-shift dispersed Mz (LSD-Mz) mode. It is realized combining various features; (1) high power off-resonant optical pumping; (2) Mz configuration, where pumping light and magnetic field of interest are oriented parallel to each other; (3) use of small alkali metal vapor cells of identical properties in integrated array structures, where two such cells are pumped by circularly polarized light of opposite helicity; and (4) subtraction of the Mz signals of these two cells. The LSD-Mz magnetometer's performance depends on the inherent and very complex interplay of input parameters. In order to find the configuration of optimal magnetometer resolution, a sensitivity analysis of the input parameters by means of Latin Hypercube Sampling was carried out. The resulting datasets of the multi-dimensional parameter space exploration were assessed by a subsequent physically reasonable interpretation. Finally, the best shot-noise limited magnetic field resolution was determined within that parameter space. As the result, using two 50 mm3 integrated vapor cells a magnetic ﬁeld resolution below 10 fT/√Hz at Earth's magnetic ﬁeld strength is possible.
Directory of Open Access Journals (Sweden)
Tamer Mekky Ahmed Habib
2014-06-01
Full Text Available The main goal of this research is to establish spacecraft orbit and attitude control algorithms based on extended Kalman filter which provides estimates of spacecraft orbital and attitude states. The control and estimation algorithms must be capable of dealing with the spacecraft conditions during the detumbling and attitude acquisition modes of operation. These conditions are characterized by nonlinearities represented by large initial attitude angles, large initial angular velocities, large initial attitude estimation error, and large initial position estimation error. All of the developed estimation and control algorithms are suitable for application to the next Egyptian scientific satellite, EGYPTSAT-2. The parameters of the case-study spacecraft are similar but not identical to the former Egyptian satellite EGYPTSAT-1. This is done because the parameters of EGYPTSAT-2 satellite have not been consolidated yet. The sensors utilized are gyro, magnetometer, and GPS. Gyro and magnetometer are utilized to provide measurements for the estimates of spacecraft attitude state vector where as magnetometer and GPS are utilized to provide measurements for the estimates of spacecraft orbital state vector.
A Test Of Cpt And Lorentz Symmetry Using A Potassium- Helium-3 Co-magnetometer
Kornack, T W
2005-01-01
A K-3He co-magnetometer has been developed for a test of Lorentz and CPT symmetry. Polarized K vapor forms a spin-exchange relaxation-free (SERF) magnetometer that has record sensitivity of about 1 fT/ Hz . The polarized 3He effectively suppresses sensitivity to the magnetic fields and gradients. Together, the K-3He co-magnetometer retains sensitivity to anomalous, CPT- and Lorentz- violating fields that couple to electron and nuclear spins differently than a normal magnetic field. Data over the course of 15 months provide upper limits on the coupling energy of a CPT-violating field to neutron spin, b˜n < 1.4 × 10−31 GeV, to proton spin, b˜p < 4.4 × 10−30 GeV, and to electron spin, b˜e < 1.0 × 10−28 GeV. These limits are consistent with the existing limits of b˜n < 1.1 × 10−31 GeV (Bear et al., 2002) and b˜ e < 3.0 × 10−29 Ge...
MgB{sub 2} magnetometer with a directly coupled pick-up loop
Energy Technology Data Exchange (ETDEWEB)
Portesi, C [Istituto Elettrotecnico Nazionale Galileo Ferraris, Strada delle Cacce 91, I-10135 Turin (Italy); Mijatovic, D [Low Temperature Division and Mesa Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Veldhuis, D [Low Temperature Division and Mesa Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Brinkman, A [Low Temperature Division and Mesa Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Monticone, E [Istituto Elettrotecnico Nazionale Galileo Ferraris, Strada delle Cacce 91, I-10135 Turin (Italy); Gonnelli, R S [INFM, Dipartimento di Fisica, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Turin (Italy)
2006-05-15
In this work, we show the results obtained in the fabrication and characterization of an MgB{sub 2} magnetometer with a directly coupled pick-up loop. We used an all in situ technique for fabricating magnesium diboride films, which consists of the co-evaporation of B and Mg by means of an e-gun and a resistive heater respectively. Consequently, we realized the superconducting device, which incorporates two nanobridges as weak links in a superconducting loop. The nanobridges were realized by focused ion beam milling; they were 240 nm wide and had a critical current density of 10{sup 7} A cm{sup -2}. The magnetometer was characterized at different temperatures and also measurements of the noise levels have been performed. The device shows Josephson quantum interference up to 20 K and the calculated effective area at low temperatures was 0.24 mm{sup 2}. The transport properties of the magnetometer allow determining fundamental materials properties of the MgB{sub 2} thin films, such as the penetration depth.
Directory of Open Access Journals (Sweden)
M. O. Archer
2015-06-01
Full Text Available We present the first in-flight results from a novel miniaturised anisotropic magnetoresistive space magnetometer, MAGIC (MAGnetometer from Imperial College, aboard the first CINEMA (CubeSat for Ions, Neutrals, Electrons and MAgnetic fields spacecraft in low Earth orbit. An attitude-independent calibration technique is detailed using the International Geomagnetic Reference Field (IGRF, which is temperature dependent in the case of the outboard sensor. We show that the sensors accurately measure the expected absolute field to within 2% in attitude mode and 1% in science mode. Using a simple method we are able to estimate the spacecraft's attitude using the magnetometer only, thus characterising CINEMA's spin, precession and nutation. Finally, we show that the outboard sensor is capable of detecting transient physical signals with amplitudes of ~ 20–60 nT. These include field-aligned currents at the auroral oval, qualitatively similar to previous observations, which agree in location with measurements from the DMSP (Defense Meteorological Satellite Program and POES (Polar-orbiting Operational Environmental Satellites spacecraft. Thus, we demonstrate and discuss the potential science capabilities of the MAGIC instrument onboard a CubeSat platform.
Archer, M. O.; Horbury, T. S.; Brown, P.; Eastwood, J. P.; Oddy, T. M.; Whiteside, B. J.; Sample, J. G.
2015-06-01
We present the first in-flight results from a novel miniaturised anisotropic magnetoresistive space magnetometer, MAGIC (MAGnetometer from Imperial College), aboard the first CINEMA (CubeSat for Ions, Neutrals, Electrons and MAgnetic fields) spacecraft in low Earth orbit. An attitude-independent calibration technique is detailed using the International Geomagnetic Reference Field (IGRF), which is temperature dependent in the case of the outboard sensor. We show that the sensors accurately measure the expected absolute field to within 2% in attitude mode and 1% in science mode. Using a simple method we are able to estimate the spacecraft's attitude using the magnetometer only, thus characterising CINEMA's spin, precession and nutation. Finally, we show that the outboard sensor is capable of detecting transient physical signals with amplitudes of ~ 20-60 nT. These include field-aligned currents at the auroral oval, qualitatively similar to previous observations, which agree in location with measurements from the DMSP (Defense Meteorological Satellite Program) and POES (Polar-orbiting Operational Environmental Satellites) spacecraft. Thus, we demonstrate and discuss the potential science capabilities of the MAGIC instrument onboard a CubeSat platform.
Atom Skimmers and Atom Lasers Utilizing Them
Hulet, Randall; Tollett, Jeff; Franke, Kurt; Moss, Steve; Sackett, Charles; Gerton, Jordan; Ghaffari, Bita; McAlexander, W.; Strecker, K.; Homan, D.
2005-01-01
Atom skimmers are devices that act as low-pass velocity filters for atoms in thermal atomic beams. An atom skimmer operating in conjunction with a suitable thermal atomic-beam source (e.g., an oven in which cesium is heated) can serve as a source of slow atoms for a magneto-optical trap or other apparatus in an atomic-physics experiment. Phenomena that are studied in such apparatuses include Bose-Einstein condensation of atomic gases, spectra of trapped atoms, and collisions of slowly moving atoms. An atom skimmer includes a curved, low-thermal-conduction tube that leads from the outlet of a thermal atomic-beam source to the inlet of a magneto-optical trap or other device in which the selected low-velocity atoms are to be used. Permanent rare-earth magnets are placed around the tube in a yoke of high-magnetic-permeability material to establish a quadrupole or octupole magnetic field leading from the source to the trap. The atoms are attracted to the locus of minimum magnetic-field intensity in the middle of the tube, and the gradient of the magnetic field provides centripetal force that guides the atoms around the curve along the axis of the tube. The threshold velocity for guiding is dictated by the gradient of the magnetic field and the radius of curvature of the tube. Atoms moving at lesser velocities are successfully guided; faster atoms strike the tube wall and are lost from the beam.
Magnetometer Data in the Classroom as a part of the NASA THEMIS Satellite Mission
Peticolas, L. M.; Bean, J.; Walker, A.
2011-12-01
The NASA-funded THEMIS mission was designed to determine the onset time and location of magnetic substorms of Earth's space environment, a prerequisite to understanding space weather. THEMIS is an acronym for Time History of Events and Macroscale Interactions during Substorms. he Geomagnetic Event Observation Network by Students (GEONS) project was the flagship, formal education component of the E/PO program. With the placement of magnetometers in the proximity of rural schools throughout the country, middle and high school teachers along with their students benefited from the opportunity to work with 'real-time' data and participated in hands-on space science activities. Particular attention was paid to placing the magnetometer stations at schools in rural communities whose students were traditionally underserved and underrepresented in the sciences. The project offered to the teachers of these students long-term professional development opportunities that centered around THEMIS-related space science and the magnetometer data. The THEMIS E/PO final evaluation report for the main phase of the THEMIS mission covered the period from 2003-2009, describing the impact of this program such as this program placed magnetometers sites at 13 rural, underserved schools/communities, two-fifths of which are on tribal lands; and provided intensive professional development for 20 teachers from 2004 through 2009. A core group of eight teachers estimated reaching more than 2,720 students with THEMIS-related materials/ideas. 75% of these students are minorities in science. Core teachers provided evidence of the project's positive impact on students' attitudes toward science and their choices for courses that position them for STEM-related careers. Core teachers reported sharing THEMIS-related materials/ideas with 275 colleagues. The NewsHour with Jim Lehrer featured the Petersburg, Alaska site potentially reaching more than 5 million viewers in two airings, according to Nielsen
The QuakeFinder Magnetometer Network - a Platform for Earth and Space Science Research
Bleier, T.; Kappler, K. N.; Schneider, D.
2016-12-01
QuakeFinder (QF) is a humanitarian research and development project attempting to characterize earth-emitting electromagnetic (EM) signals as potential precursors to earthquakes. Beginning in 2005, QF designed, built, deployed and now maintains an array of 165 remote monitoring stations in 6 countries (US/California, Taiwan, Greece, Indonesia, Peru and Chile). Having amassed approximately 70 TB of data and greater than 140 earthquakes (M4+), QF is focused on the data analysis and signal processing algorithms in our effort to enable a forecasting capability. QF's autonomous stations, located along major fault lines, collect and transmit electromagnetic readings from 3-axis induction magnetometers and positive/negative ion sensors, a geophone, as well as various station health status and local conditions. The induction magnetometers, oriented N-S,E-W and vertically, have a 40 nT range and 1 pT sensitivity. Data is continuously collected at 50 samples/sec (sps), GPS time-stamped and transmitted, primarily through cell phone networks, to our data center in Palo Alto, California. The induction magnetometers routinely detect subtle geomagnetic and ionospheric disturbances as observed worldwide. QF seeks to make available both historic data and the array platform to strategic partners in the EM-related research and operation fields. The QF system will be described in detail with examples of local and regional geomagnetic activity. The stations are robust and will be undergoing a system-level upgrade in the near future. Domestically, QF maintains a 98% `up time' among the 120 stations in California while internationally our metric is typically near 80%. Irregular cell phone reception is chief among the reasons for outages although little data has been lost as the stations can store up to 90 days of data. These data are retrieved by QF personnel or, when communication is reestablished, the QF data ingest process automatically updates the database. Planned station upgrades
Anderson, David; Yunes, Nicolás; Barausse, Enrico
2016-11-01
Certain scalar-tensor theories of gravity that generalize Jordan-Fierz-Brans-Dicke theory are known to predict nontrivial phenomenology for neutron stars. In these theories, first proposed by Damour and Esposito-Farèse, the scalar field has a standard kinetic term and couples conformally to the matter fields. The weak equivalence principle is therefore satisfied, but scalar effects may arise in strong-field regimes, e.g., allowing for violations of the strong equivalence principle in neutron stars ("spontaneous scalarization") or in sufficiently tight binary neutron-star systems ("dynamical/induced scalarization"). The original scalar-tensor theory proposed by Damour and Esposito-Farèse is in tension with Solar System constraints (for couplings that lead to scalarization), if one accounts for cosmological evolution of the scalar field and no mass term is included in the action. We extend here the conformal coupling of that theory, in order to ascertain if, in this way, Solar System tests can be passed, while retaining a nontrivial phenomenology for neutron stars. We find that, even with this generalized conformal coupling, it is impossible to construct a theory that passes both big bang nucleosynthesis and Solar System constraints, while simultaneously allowing for scalarization in isolated/binary neutron stars.
Search for scalar top quark and scalar bottom quark in proton anti-proton collisions at √s = 1.8TeV
Energy Technology Data Exchange (ETDEWEB)
Holck, Christopher Matthew [Univ. of Pennsylvania, Philadelphia, PA (United States)
1999-01-01
We present the results of a search for direct pair production of scalar top (or scalar bottom) quarks followed by the decay of scalar top (or scalar bottom) quark to a charm quark (or bottom quark) and a neutralino using 88 pb^{–1} of data from p$\\bar{p}$ collisions at √s = 1.8 TeV. The experimental signature is two charm (or two bottom) jets plus significant missing energy. The number of events which pass all our selection criteria is consistent with our expectations from Standard Model processes. We observe 11(5) events in the scalar top (scalar bottom) analysis and expect 14.5 ± 4.2(5.8 ± 1.8). We use a next-to-leading order scalar quark cross section calculation to excluded points, at the 95% C.L., as a function of the scalar top mass (or scalar bottom mass) and the neutralino mass
Relativistic scalar-vector models of the N-N and N-nuclear interactions
Energy Technology Data Exchange (ETDEWEB)
Green, A.E.S.
1985-01-01
This paper for the Proceedings of Conference an Anti-Nucleon and Nucleon-Nucleus Interactions summarizes work by the principal investigator and his collaborators on the nucleon-nucleon (N-N) and nucleon-nuclear (N-eta) interactions. It draws heavily on a paper presented at the Many Body Conference in Rome in 1972 but also includes a brief review of our phenomenological N-eta interaction studies. We first summarize our 48-49 generalized scalar-vector meson field theory model of the N-N interactions. This is followed by a brief description of our phenomenological work in the 50's on the N-eta interaction sponsored by the Atomic Energy Commission (the present DOE). This work finally led to strong velocity dependent potentials with spin orbit and isospin terms for shell and optical model applications. This is followed by a section on the Emergence of One-Boson Exchange Models describing developments in the 60's of quantitative generalized one boson exchange potentials (GOBEP) including our purely relativistic N-N analyses. Then follows a section on the application of this meson field model to the N-eta interaction, in particular to spherical closed shell nuclei. This work was sponsored by AFOSR but funding was halted with the Mansfield amendment. We conclude with a discussion of subsequent collateral work by former colleagues and by others who have converged upon scalar-vector relativistic models of N-N, antiN-N, N-eta and antiN-eta interactions and some lessons learned from this extended endeavor. 61 refs.
Structures and Intermittency in a Passive Scalar Model
Vergassola, M.; Mazzino, A.
1997-09-01
Perturbative expansions for intermittency scaling exponents in the Kraichnan passive scalar model [Phys. Rev. Lett. 72, 1016 (1994)] are investigated. A one-dimensional compressible model is considered for this purpose. High resolution Monte Carlo simulations using an Ito approach adapted to an advecting velocity field with a very short correlation time are performed and lead to clean scaling behavior for passive scalar structure functions. Perturbative predictions for the scaling exponents around the Gaussian limit of the model are derived as in the Kraichnan model. Their comparison with the simulations indicates that the scale-invariant perturbative scheme correctly captures the inertial range intermittency corrections associated with the intense localized structures observed in the dynamics.
A T Matrix Method Based upon Scalar Basis Functions
Mackowski, D.W.; Kahnert, F. M.; Mishchenko, Michael I.
2013-01-01
A surface integral formulation is developed for the T matrix of a homogenous and isotropic particle of arbitrary shape, which employs scalar basis functions represented by the translation matrix elements of the vector spherical wave functions. The formulation begins with the volume integral equation for scattering by the particle, which is transformed so that the vector and dyadic components in the equation are replaced with associated dipole and multipole level scalar harmonic wave functions. The approach leads to a volume integral formulation for the T matrix, which can be extended, by use of Green's identities, to the surface integral formulation. The result is shown to be equivalent to the traditional surface integral formulas based on the VSWF basis.
Exploring the structure of a possible light scalar nonet
Energy Technology Data Exchange (ETDEWEB)
Black, Deirdre; Fariborz, Amir H.; Schechter, Joseph [Syracuse Univ., Dept. of Physics, Syracuse, NY (United States)
2000-12-01
We first review the work of the Syracuse group, which uses an effective chiral Lagrangian approach, on meson-meson scattering. An illustration providing evidence for the existence of a strange scalar resonance of mass around 900 MeV is given. An attempt to fit this {kappa}(900) together with a similarly obtained {sigma}(560) and the well known a{sub 0}(980) and f{sub 0}(980) into a nonet pattern suggests that the underlying structure is closer to a dual quark-dual antiquark than to a quark-antiquark. A possible mechanism to explain a next higher-in mass scalar meson nonet is also discussed. This involves mixing between qq-bar and qqq-barq-bar states. (author)
Scalar mesons above and below 1 GeV
Energy Technology Data Exchange (ETDEWEB)
Close, Frank E. [Department of Theoretical Physics, University of Oxford, Oxford (United Kingdom)]. E-mail: F.Close@physics.ox.ac.uk; Toernqvist, Nils A. [Department of Physical Sciences, University of Helsinki, Helsinki (Finland)]. E-mail: nils.tornqvist@helsinki.fi
2002-10-01
We show that two nonets and a glueball provide a consistent description of data on scalar mesons below 1.7 GeV. Above 1 GeV the states form a conventional qq-bar nonet mixed with the glueball of lattice QCD. Below 1 GeV the states also form a nonet, as implied by the attractive forces of QCD, but of a more complicated nature. Near the centre they are (qq)3-bar(q-barq-bar){sub 3} in S-wave, with some qq-bar in P-wave, but further out they rearrange as (qq-bar){sub 1}(qq-bar){sub 1} and finally as meson-meson states. A simple effective chiral model for such a system with two scalar nonets can be made involving two coupled linear sigma models. One of these could be looked upon as the Higgs sector of nonpertubative QCD. (author)
Stationary scalar clouds around a BTZ black hole
Ferreira, Hugo R. C.; Herdeiro, Carlos A. R.
2017-10-01
We establish the existence of stationary clouds of massive test scalar fields around BTZ black holes. These clouds are zero-modes of the superradiant instability and are possible when Robin boundary conditions (RBCs) are considered at the AdS boundary. These boundary conditions are the most general ones that ensure the AdS space is an isolated system, and include, as a particular case, the commonly considered Dirichlet or Neumann-type boundary conditions (DBCs or NBCs). We obtain an explicit, closed form, resonance condition, relating the RBCs that allow the existence of normalizable (and regular on and outside the horizon) clouds to the system's parameters. Such RBCs never include pure DBCs or NBCs. We illustrate the spatial distribution of these clouds, their energy and angular momentum density for some cases. Our results show that BTZ black holes with scalar hair can be constructed, as the non-linear realization of these clouds.
Performance analysis of compressed sensing with uniform scalar quantisation
Lu, Wei; Wang, Desheng; Liu, Jian; Liu, Yingzhuang
2014-08-01
In compressed sensing, the sampling rate can be greatly reduced based on the sparsity of the original signal; however, quantisation is one key aspect in signal acquirement. This article studies the scalar quantisation and its impacts on the compressed sensing. We consider the case in which both the original and the measurement signals are quantised or discrete, which widely exists in the practical applications such as the finite precision signals in the computer and the finite-set original signal in communication systems. We derive the recovery probability bound and the necessary measurement number bound for compressed sensing with scalar quantisation and simulate three modified compressed sensing recovery algorithms. Simulations show that coarse quantisation can be applied in compressed sensing for discrete or quantised sparse signal with sampling and storage efficiency.
Treatment of anisotropic damage development within a scalar damage formulation
Chan, K. S.; Bodner, S. R.; Munson, D. E.
This paper is concerned with describing a damage mechanics formulation which provides for non-isotropic effects using a scalar damage variable. An investigation has been in progress for establishing the constitutive behavior of rock salt at long times and low to moderate confining pressures in relation to the possible use of excavated rooms in rock salt formations as repositories for nuclear waste. An important consideration is the effect of damage manifested principally by the formation of shear induced wing cracks which have a stress dependent orientation. The analytical formulation utilizes a scalar damage parameter, but is capable of indicating the non-isotropic dependence of inelastic straining on the stress state and the confining pressure. Also, the equations indicate the possibility of volumetric expansions leading to the onset of tertiary creep and eventually rupture if the damage variable reaches a critical value.
Galilean-invariant scalar fields can strengthen gravitational lensing.
Wyman, Mark
2011-05-20
The mystery of dark energy suggests that there is new gravitational physics on long length scales. Yet light degrees of freedom in gravity are strictly limited by Solar System observations. We can resolve this apparent contradiction by adding a Galilean-invariant scalar field to gravity. Called Galileons, these scalars have strong self-interactions near overdensities, like the Solar System, that suppress their dynamical effect. These nonlinearities are weak on cosmological scales, permitting new physics to operate. In this Letter, we point out that a massive-gravity-inspired coupling of Galileons to stress energy can enhance gravitational lensing. Because the enhancement appears at a fixed scaled location for dark matter halos of a wide range of masses, stacked cluster analysis of weak lensing data should be able to detect or constrain this effect.
Scalar field as a Bose-Einstein condensate?
Energy Technology Data Exchange (ETDEWEB)
Castellanos, Elías; Escamilla-Rivera, Celia [Mesoamerican Centre for Theoretical Physics (ICTP regional headquarters in Central America, the Caribbean and Mexico), Universidad Autónoma de Chiapas, Carretera Zapata Km. 4, Real del Bosque (Terán), 29040, Tuxtla Gutiérrez, Chiapas (Mexico); Macías, Alfredo [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, A.P. 55-534, Mexico D.F. 09340 (Mexico); Núñez, Darío, E-mail: ecastellanos@mctp.mx, E-mail: cescamilla@mctp.mx, E-mail: amac@xanum.uam.mx, E-mail: nunez@nucleares.unam.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior C.U., A.P. 70-543, México D.F. 04510 (Mexico)
2014-11-01
We discuss the analogy between a classical scalar field with a self-interacting potential, in a curved spacetime described by a quasi-bounded state, and a trapped Bose-Einstein condensate. In this context, we compare the Klein-Gordon equation with the Gross-Pitaevskii equation. Moreover, the introduction of a curved background spacetime endows, in a natural way, an equivalence to the Gross-Pitaevskii equation with an explicit confinement potential. The curvature also induces a position dependent self-interaction parameter. We exploit this analogy by means of the Thomas-Fermi approximation, commonly used to describe the Bose-Einstein condensate, in order to analyze the quasi bound scalar field distribution surrounding a black hole.
Search for First Generation Scalar Leptoquarks in the e$\
Chatrchyan, Serguei; Sirunyan, Albert M; Tumasyan, Armen; Adam, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Erö, Janos; Fabjan, Christian; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hammer, Josef; Haensel, Stephan; Hoch, Michael; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Kiesenhofer, Wolfgang; Krammer, Manfred; Liko, Dietrich; Mikulec, Ivan; Pernicka, Manfred; Rohringer, Herbert; Schöfbeck, Robert; Strauss, Josef; Taurok, Anton; Teischinger, Florian; Wagner, Philipp; Waltenberger, Wolfgang; Walzel, Gerhard; Widl, Edmund; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Bansal, Sunil; Benucci, Leonardo; De Wolf, Eddi A; Janssen, Xavier; Maes, Joris; Maes, Thomas; Mucibello, Luca; Ochesanu, Silvia; Roland, Benoit; Rougny, Romain; Selvaggi, Michele; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Blekman, Freya; Blyweert, Stijn; D'Hondt, Jorgen; Devroede, Olivier; Gonzalez Suarez, Rebeca; Kalogeropoulos, Alexis; Maes, Michael; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Villella, Ilaria; Charaf, Otman; Clerbaux, Barbara; De Lentdecker, Gilles; Dero, Vincent; Gay, Arnaud; Hammad, Gregory Habib; Hreus, Tomas; Marage, Pierre Edouard; Thomas, Laurent; Vander Velde, Catherine; Vanlaer, Pascal; Adler, Volker; Cimmino, Anna; Costantini, Silvia; Grunewald, Martin; Klein, Benjamin; Lellouch, Jérémie; Marinov, Andrey; Mccartin, Joseph; Ryckbosch, Dirk; Thyssen, Filip; Tytgat, Michael; Vanelderen, Lukas; Verwilligen, Piet; Walsh, Sinead; Zaganidis, Nicolas; Basegmez, Suzan; Bruno, Giacomo; Caudron, Julien; Ceard, Ludivine; Cortina Gil, Eduardo; De Favereau De Jeneret, Jerome; Delaere, Christophe; Favart, Denis; Giammanco, Andrea; Grégoire, Ghislain; Hollar, Jonathan; Lemaitre, Vincent; Liao, Junhui; Militaru, Otilia; Ovyn, Severine; Pagano, Davide; Pin, Arnaud; Piotrzkowski, Krzysztof; Schul, Nicolas; Beliy, Nikita; Caebergs, Thierry; Daubie, Evelyne; Alves, Gilvan; De Jesus Damiao, Dilson; Pol, Maria Elena; Henrique Gomes E Souza, Moacyr; Carvalho, Wagner; Melo Da Costa, Eliza; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Mundim, Luiz; Nogima, Helio; Oguri, Vitor; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Silva Do Amaral, Sheila Mara; Sznajder, Andre; Bernardes, Cesar Augusto; De Almeida Dias, Flavia; Tomei, Thiago; De Moraes Gregores, Eduardo; Lagana, Caio; Da Cunha Marinho, Franciole; Mercadante, Pedro G; Novaes, Sergio F; Padula, Sandra; Darmenov, Nikolay; Genchev, Vladimir; Iaydjiev, Plamen; Piperov, Stefan; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Tcholakov, Vanio; Trayanov, Rumen; Dimitrov, Anton; Hadjiiska, Roumyana; Karadzhinova, Aneliya; Kozhuharov, Venelin; Litov, Leander; Mateev, Matey; Pavlov, Borislav; Petkov, Peicho; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Jiang, Chun-Hua; Liang, Dong; Liang, Song; Meng, Xiangwei; Tao, Junquan; Wang, Jian; Wang, Jian; Wang, Xianyou; Wang, Zheng; Xiao, Hong; Xu, Ming; Zang, Jingjing; Zhang, Zhen; Ban, Yong; Guo, Shuang; Guo, Yifei; Li, Wenbo; Mao, Yajun; Qian, Si-Jin; Teng, Haiyun; Zhu, Bo; Zou, Wei; Cabrera, Andrés; Gomez Moreno, Bernardo; Ocampo Rios, Alberto Andres; Osorio Oliveros, Andres Felipe; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Lelas, Karlo; Plestina, Roko; Polic, Dunja; Puljak, Ivica; Antunovic, Zeljko; Dzelalija, Mile; Brigljevic, Vuko; Duric, Senka; Kadija, Kreso; Morovic, Srecko; Attikis, Alexandros; Galanti, Mario; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Finger, Miroslav; Finger Jr, Michael; Aly, Ayman; Ellithi Kamel, Ali; Khalil, Shaaban; Hektor, Andi; Kadastik, Mario; Müntel, Mait; Raidal, Martti; Rebane, Liis; Azzolini, Virginia; Eerola, Paula; Fedi, Giacomo; Czellar, Sandor; Härkönen, Jaakko; Heikkinen, Mika Aatos; Karimäki, Veikko; Kinnunen, Ritva; Kortelainen, Matti J; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Ungaro, Donatella; Wendland, Lauri; Banzuzi, Kukka; Korpela, Arja; Tuuva, Tuure; Sillou, Daniel; Besancon, Marc; Choudhury, Somnath; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Ferri, Federico; Ganjour, Serguei; Gentit, François-Xavier; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Malcles, Julie; Marionneau, Matthieu; Millischer, Laurent; Rander, John; Rosowsky, André; Shreyber, Irina; Titov, Maksym; Verrecchia, Patrice; Baffioni, Stephanie; Beaudette, Florian; Benhabib, Lamia; Bianchini, Lorenzo; Bluj, Michal; Broutin, Clementine; Busson, Philippe; Charlot, Claude; Dahms, Torsten; Dobrzynski, Ludwik; Elgammal, Sherif; Granier de Cassagnac, Raphael; Haguenauer, Maurice; Miné, Philippe; Mironov, Camelia; Ochando, Christophe; Paganini, Pascal; Sabes, David; Salerno, Roberto; Sirois, Yves; Thiebaux, Christophe; Wyslouch, Bolek; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Bloch, Daniel; Bodin, David; Brom, Jean-Marie; Cardaci, Marco; Chabert, Eric Christian; Collard, Caroline; Conte, Eric; Drouhin, Frédéric; Ferro, Cristina; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Greder, Sebastien; Juillot, Pierre; Karim, Mehdi; Le Bihan, Anne-Catherine; Mikami, Yoshinari; Van Hove, Pierre; Fassi, Farida; Mercier, Damien; Baty, Clement; Beauceron, Stephanie; Beaupere, Nicolas; Bedjidian, Marc; Bondu, Olivier; Boudoul, Gaelle; Boumediene, Djamel; Brun, Hugues; Chasserat, Julien; Chierici, Roberto; Contardo, Didier; Depasse, Pierre; El Mamouni, Houmani; Fay, Jean; Gascon, Susan; Ille, Bernard; Kurca, Tibor; Le Grand, Thomas; Lethuillier, Morgan; Mirabito, Laurent; Perries, Stephane; Sordini, Viola; Tosi, Silvano; Tschudi, Yohann; Verdier, Patrice; Lomidze, David; Anagnostou, Georgios; Edelhoff, Matthias; Feld, Lutz; Heracleous, Natalie; Hindrichs, Otto; Jussen, Ruediger; Klein, Katja; Merz, Jennifer; Mohr, Niklas; Ostapchuk, Andrey; Perieanu, Adrian; Raupach, Frank; Sammet, Jan; Schael, Stefan; Sprenger, Daniel; Weber, Hendrik; Weber, Martin; Wittmer, Bruno; Ata, Metin; Bender, Walter; Dietz-Laursonn, Erik; Erdmann, Martin; Frangenheim, Jens; Hebbeker, Thomas; Hinzmann, Andreas; Hoepfner, Kerstin; Klimkovich, Tatsiana; Klingebiel, Dennis; Kreuzer, Peter; Lanske, Dankfried; Magass, Carsten; Merschmeyer, Markus; Meyer, Arnd; Papacz, Paul; Pieta, Holger; Reithler, Hans; Schmitz, Stefan Antonius; Sonnenschein, Lars; Steggemann, Jan; Teyssier, Daniel; Bontenackels, Michael; Davids, Martina; Duda, Markus; Flügge, Günter; Geenen, Heiko; Giffels, Manuel; Haj Ahmad, Wael; Heydhausen, Dirk; Kress, Thomas; Kuessel, Yvonne; Linn, Alexander; Nowack, Andreas; Perchalla, Lars; Pooth, Oliver; Rennefeld, Jörg; Sauerland, Philip; Stahl, Achim; Thomas, Maarten; Tornier, Daiske; Zoeller, Marc Henning; Aldaya Martin, Maria; Behrenhoff, Wolf; Behrens, Ulf; Bergholz, Matthias; Bethani, Agni; Borras, Kerstin; Cakir, Altan; Campbell, Alan; Castro, Elena; Dammann, Dirk; Eckerlin, Guenter; Eckstein, Doris; Flossdorf, Alexander; Flucke, Gero; Geiser, Achim; Hauk, Johannes; Jung, Hannes; Kasemann, Matthias; Katkov, Igor; Katsas, Panagiotis; Kleinwort, Claus; Kluge, Hannelies; Knutsson, Albert; Krämer, Mira; Krücker, Dirk; Kuznetsova, Ekaterina; Lange, Wolfgang; Lohmann, Wolfgang; Mankel, Rainer; Marienfeld, Markus; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mnich, Joachim; Mussgiller, Andreas; Olzem, Jan; Petrukhin, Alexey; Pitzl, Daniel; Raspereza, Alexei; Raval, Amita; Rosin, Michele; Schmidt, Ringo; Schoerner-Sadenius, Thomas; Sen, Niladri; Spiridonov, Alexander; Stein, Matthias; Tomaszewska, Justyna; Walsh, Roberval; Wissing, Christoph; Autermann, Christian; Blobel, Volker; Bobrovskyi, Sergei; Draeger, Jula; Enderle, Holger; Gebbert, Ulla; Görner, Martin; Kaschube, Kolja; Kaussen, Gordon; Kirschenmann, Henning; Klanner, Robert; Lange, Jörn; Mura, Benedikt; Naumann-Emme, Sebastian; Nowak, Friederike; Pietsch, Niklas; Sander, Christian; Schettler, Hannes; Schleper, Peter; Schlieckau, Eike; Schröder, Matthias; Schum, Torben; Schwandt, Joern; Stadie, Hartmut; Steinbrück, Georg; Thomsen, Jan; Barth, Christian; Bauer, Julia; Berger, Joram; Buege, Volker; Chwalek, Thorsten; De Boer, Wim; Dierlamm, Alexander; Dirkes, Guido; Feindt, Michael; Gruschke, Jasmin; Hackstein, Christoph; Hartmann, Frank; Heinrich, Michael; Held, Hauke; Hoffmann, Karl-Heinz; Honc, Simon; Komaragiri, Jyothsna Rani; Kuhr, Thomas; Martschei, Daniel; Mueller, Steffen; Müller, Thomas; Niegel, Martin; Oberst, Oliver; Oehler, Andreas; Ott, Jochen; Peiffer, Thomas; Quast, Gunter; Rabbertz, Klaus; Ratnikov, Fedor; Ratnikova, Natalia; Renz, Manuel; Saout, Christophe; Scheurer, Armin; Schieferdecker, Philipp; Schilling, Frank-Peter; Schott, Gregory; Simonis, Hans-Jürgen; Stober, Fred-Markus Helmut; Troendle, Daniel; Wagner-Kuhr, Jeannine; Weiler, Thomas; Zeise, Manuel; Zhukov, Valery; Ziebarth, Eva Barbara; Daskalakis, Georgios; Geralis, Theodoros; Kesisoglou, Stilianos; Kyriakis, Aristotelis; Loukas, Demetrios; Manolakos, Ioannis; Markou, Athanasios; Markou, Christos; Mavrommatis, Charalampos; Ntomari, Eleni; Petrakou, Eleni; Gouskos, Loukas; Mertzimekis, Theodoros; Panagiotou, Apostolos; Stiliaris, Efstathios; Evangelou, Ioannis; Foudas, Costas; Kokkas, Panagiotis; Manthos, Nikolaos; Papadopoulos, Ioannis; Patras, Vaios; Triantis, Frixos A; Aranyi, Attila; Bencze, Gyorgy; Boldizsar, Laszlo; Hajdu, Csaba; Hidas, Pàl; Horvath, Dezso; Kapusi, Anita; Krajczar, Krisztian; Sikler, Ferenc; Veres, Gabor Istvan; Vesztergombi, Gyorgy; Beni, Noemi; Molnar, Jozsef; Palinkas, Jozsef; Szillasi, Zoltan; Veszpremi, Viktor; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Beri, Suman Bala; Bhatnagar, Vipin; Dhingra, Nitish; Gupta, Ruchi; Jindal, Monika; Kaur, Manjit; Kohli, Jatinder Mohan; Mehta, Manuk Zubin; Nishu, Nishu; Saini, Lovedeep Kaur; Sharma, Archana; Singh, Anil; Singh, Jasbir; Singh, Supreet Pal; Ahuja, Sudha; Bhattacharya, Satyaki; Choudhary, Brajesh C; Gomber, Bhawna; Gupta, Pooja; Jain, Sandhya; Jain, Shilpi; Khurana, Raman; Kumar, Ashok; Naimuddin, Md; Ranjan, Kirti; Shivpuri, Ram Krishen; Dutta, Suchandra; Sarkar, Subir; Choudhury, Rajani Kant; Dutta, Dipanwita; Kailas, Swaminathan; Kumar, Vineet; Mehta, Pourus; Mohanty, Ajit Kumar; Pant, Lalit Mohan; Shukla, Prashant; Aziz, Tariq; Guchait, Monoranjan; Gurtu, Atul; Maity, Manas; Majumder, Devdatta; Majumder, Gobinda; Mazumdar, Kajari; Mohanty, Gagan Bihari; Saha, Anirban; Sudhakar, Katta; Wickramage, Nadeesha; Banerjee, Sudeshna; Dugad, Shashikant; Mondal, Naba Kumar; Arfaei, Hessamaddin; Bakhshiansohi, Hamed; Etesami, Seyed Mohsen; Fahim, Ali; Hashemi, Majid; Jafari, Abideh; Khakzad, Mohsen; Mohammadi, Abdollah; Mohammadi Najafabadi, Mojtaba; Paktinat Mehdiabadi, Saeid; Safarzadeh, Batool; Zeinali, Maryam; Abbrescia, Marcello; Barbone, Lucia; Calabria, Cesare; Colaleo, Anna; Creanza, Donato; De Filippis, Nicola; De Palma, Mauro; Fiore, Luigi; Iaselli, Giuseppe; Lusito, Letizia; Maggi, Giorgio; Maggi, Marcello; Manna, Norman; Marangelli, Bartolomeo; My, Salvatore; Nuzzo, Salvatore; Pacifico, Nicola; Pierro, Giuseppe Antonio; Pompili, Alexis; Pugliese, Gabriella; Romano, Francesco; Roselli, Giuseppe; Selvaggi, Giovanna; Silvestris, Lucia; Trentadue, Raffaello; Tupputi, Salvatore; Zito, Giuseppe; Abbiendi, Giovanni; Benvenuti, Alberto; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Giunta, Marina; Grandi, Claudio; Marcellini, Stefano; Masetti, Gianni; Meneghelli, Marco; Montanari, Alessandro; Navarria, Francesco; Odorici, Fabrizio; Perrotta, Andrea; Primavera, Federica; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gianni; Travaglini, Riccardo; Albergo, Sebastiano; Cappello, Gigi; Chiorboli, Massimiliano; Costa, Salvatore; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Frosali, Simone; Gallo, Elisabetta; Gonzi, Sandro; Lenzi, Piergiulio; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Tropiano, Antonio; Benussi, Luigi; Bianco, Stefano; Colafranceschi, Stefano; Fabbri, Franco; Piccolo, Davide; Fabbricatore, Pasquale; Musenich, Riccardo; Benaglia, Andrea; De Guio, Federico; Di Matteo, Leonardo; Gennai, Simone; Ghezzi, Alessio; Malvezzi, Sandra; Martelli, Arabella; Massironi, Andrea; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Ragazzi, Stefano; Redaelli, Nicola; Sala, Silvano; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Carrillo Montoya, Camilo Andres; Cavallo, Nicola; De Cosa, Annapaola; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lista, Luca; Merola, Mario; Paolucci, Pierluigi; Azzi, Patrizia; Bacchetta, Nicola; Bellan, Paolo; Bisello, Dario; Branca, Antonio; Carlin, Roberto; Checchia, Paolo; De Mattia, Marco; Dorigo, Tommaso; Dosselli, Umberto; Fanzago, Federica; Gasparini, Fabrizio; Gasparini, Ugo; Gozzelino, Andrea; Lacaprara, Stefano; Lazzizzera, Ignazio; Margoni, Martino; Mazzucato, Mirco; Meneguzzo, Anna Teresa; Nespolo, Massimo; Perrozzi, Luca; Pozzobon, Nicola; Ronchese, Paolo; Simonetto, Franco; Torassa, Ezio; Tosi, Mia; Vanini, Sara; Zotto, Pierluigi; Zumerle, Gianni; Baesso, Paolo; Berzano, Umberto; Ratti, Sergio P; Riccardi, Cristina; Torre, Paola; Vitulo, Paolo; Viviani, Claudio; Biasini, Maurizio; Bilei, Gian Mario; Caponeri, Benedetta; Fanò, Livio; Lariccia, Paolo; Lucaroni, Andrea; Mantovani, Giancarlo; Menichelli, Mauro; Nappi, Aniello; Romeo, Francesco; Santocchia, Attilio; Taroni, Silvia; Valdata, Marisa; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Broccolo, Giuseppe; Castaldi, Rino; D'Agnolo, Raffaele Tito; Dell'Orso, Roberto; Fiori, Francesco; Foà, Lorenzo; Giassi, Alessandro; Kraan, Aafke; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Palla, Fabrizio; Segneri, Gabriele; Serban, Alin Titus; Spagnolo, Paolo; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Barone, Luciano; Cavallari, Francesca; Del Re, Daniele; Di Marco, Emanuele; Diemoz, Marcella; Franci, Daniele; Grassi, Marco; Longo, Egidio; Meridiani, Paolo; Nourbakhsh, Shervin; Organtini, Giovanni; Pandolfi, Francesco; Paramatti, Riccardo; Rahatlou, Shahram; Rovelli, Chiara; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Biino, Cristina; Botta, Cristina; Cartiglia, Nicolo; Castello, Roberto; Costa, Marco; Demaria, Natale; Graziano, Alberto; Mariotti, Chiara; Marone, Matteo; Maselli, Silvia; Migliore, Ernesto; Mila, Giorgia; Monaco, Vincenzo; Musich, Marco; Obertino, Maria Margherita; Pastrone, Nadia; Pelliccioni, Mario; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Sola, Valentina; Solano, Ada; Staiano, Amedeo; Vilela Pereira, Antonio; Belforte, Stefano; Cossutti, Fabio; Della Ricca, Giuseppe; Gobbo, Benigno; Montanino, Damiana; Penzo, Aldo; Heo, Seong Gu; Nam, Soon-Kwon; Chang, Sunghyun; Chung, Jin Hyuk; Kim, Dong Hee; Kim, Gui Nyun; Kim, Ji Eun; Kong, Dae Jung; Park, Hyangkyu; Ro, Sang-Ryul; Son, Dohhee; Son, Dong-Chul; Son, Taejin; Kim, Jaeho; Kim, Jae Yool; Song, Sanghyeon; Choi, Suyong; Hong, Byung-Sik; Jo, Mihee; Kim, Hyunchul; Kim, Ji Hyun; Kim, Tae Jeong; Lee, Kyong Sei; Moon, Dong Ho; Park, Sung Keun; Rhee, Han-Bum; Seo, Eunsung; Sim, Kwang Souk; Choi, Minkyoo; Kang, Seokon; Kim, Hyunyong; Park, Chawon; Park, Inkyu; Park, Sangnam; Ryu, Geonmo; Choi, Young-Il; Choi, Young Kyu; Goh, Junghwan; Kim, Min Suk; Kwon, Eunhyang; Lee, Jongseok; Lee, Sungeun; Seo, Hyunkwan; Yu, Intae; Bilinskas, Mykolas Jurgis; Grigelionis, Ignas; Janulis, Mindaugas; Martisiute, Dalia; Petrov, Pavel; Sabonis, Tomas; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-de La Cruz, Ivan; Lopez-Fernandez, Ricardo; Magaña Villalba, Ricardo; Sánchez-Hernández, Alberto; Villasenor-Cendejas, Luis Manuel; Carrillo Moreno, Salvador; Vazquez Valencia, Fabiola; Salazar Ibarguen, Humberto Antonio; Casimiro Linares, Edgar; Morelos Pineda, Antonio; Reyes-Santos, Marco A; Krofcheck, David; Tam, Jason; Butler, Philip H; Doesburg, Robert; Silverwood, Hamish; Ahmad, Muhammad; Ahmed, Ijaz; Asghar, Muhammad Irfan; Hoorani, Hafeez R; Khan, Wajid Ali; Khurshid, Taimoor; Qazi, Shamona; Brona, Grzegorz; Cwiok, Mikolaj; Dominik, Wojciech; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Frueboes, Tomasz; Gokieli, Ryszard; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Wrochna, Grzegorz; Zalewski, Piotr; Almeida, Nuno; Bargassa, Pedrame; David Tinoco Mendes, Andre; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Musella, Pasquale; Nayak, Aruna; Ribeiro, Pedro Quinaz; Seixas, Joao; Varela, Joao; Afanasiev, Serguei; Bunin, Pavel; Golutvin, Igor; Kamenev, Alexey; Karjavin, Vladimir; Kozlov, Guennady; Lanev, Alexander; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Savina, Maria; Shmatov, Sergey; Smirnov, Vitaly; Volodko, Anton; Zarubin, Anatoli; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Vorobyev, Andrey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Kirsanov, Mikhail; Krasnikov, Nikolai; Matveev, Viktor; Pashenkov, Anatoli; Toropin, Alexander; Troitsky, Sergey; Epshteyn, Vladimir; Gavrilov, Vladimir; Kaftanov, Vitali; Kossov, Mikhail; Krokhotin, Andrey; Lychkovskaya, Natalia; Popov, Vladimir; Safronov, Grigory; Semenov, Sergey; Stolin, Viatcheslav; Vlasov, Evgueni; Zhokin, Alexander; Boos, Edouard; Dubinin, Mikhail; Dudko, Lev; Ershov, Alexander; Gribushin, Andrey; Kodolova, Olga; Lokhtin, Igor; Markina, Anastasia; Obraztsov, Stepan; Perfilov, Maxim; Petrushanko, Sergey; Sarycheva, Ludmila; Savrin, Viktor; Snigirev, Alexander; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Rusakov, Sergey V; Vinogradov, Alexey; Azhgirey, Igor; Bitioukov, Sergei; Grishin, Viatcheslav; Kachanov, Vassili; Konstantinov, Dmitri; Korablev, Andrey; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Slabospitsky, Sergey; Sobol, Andrei; Tourtchanovitch, Leonid; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Djordjevic, Milos; Krpic, Dragomir; Milosevic, Jovan; Aguilar-Benitez, Manuel; Alcaraz Maestre, Juan; Arce, Pedro; Battilana, Carlo; Calvo, Enrique; Cepeda, Maria; Cerrada, Marcos; Chamizo Llatas, Maria; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Diez Pardos, Carmen; Domínguez Vázquez, Daniel; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Ferrando, Antonio; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Merino, Gonzalo; Puerta Pelayo, Jesus; Redondo, Ignacio; Romero, Luciano; Santaolalla, Javier; Senghi Soares, Mara; Willmott, Carlos; Albajar, Carmen; Codispoti, Giuseppe; de Trocóniz, Jorge F; Cuevas, Javier; Fernandez Menendez, Javier; Folgueras, Santiago; Gonzalez Caballero, Isidro; Lloret Iglesias, Lara; Vizan Garcia, Jesus Manuel; Brochero Cifuentes, Javier Andres; Cabrillo, Iban Jose; Calderon, Alicia; Chuang, Shan-Huei; Duarte Campderros, Jordi; Felcini, Marta; Fernandez, Marcos; Gomez, Gervasio; Gonzalez Sanchez, Javier; Jorda, Clara; Lobelle Pardo, Patricia; Lopez Virto, Amparo; Marco, Jesus; Marco, Rafael; Martinez Rivero, Celso; Matorras, Francisco; Munoz Sanchez, Francisca Javiela; Piedra Gomez, Jonatan; Rodrigo, Teresa; Rodríguez-Marrero, Ana Yaiza; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Sobron Sanudo, Mar; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Baillon, Paul; Ball, Austin; Barney, David; Bell, Alan James; Benedetti, Daniele; Bernet, Colin; Bialas, Wojciech; Bloch, Philippe; Bocci, Andrea; Bolognesi, Sara; Bona, Marcella; Breuker, Horst; Bunkowski, Karol; Camporesi, Tiziano; Cerminara, Gianluca; Coarasa Perez, Jose Antonio; Curé, Benoît; D'Enterria, David; De Roeck, Albert; Di Guida, Salvatore; Dupont-Sagorin, Niels; Elliott-Peisert, Anna; Frisch, Benjamin; Funk, Wolfgang; Gaddi, Andrea; Georgiou, Georgios; Gerwig, Hubert; Gigi, Dominique; Gill, Karl; Giordano, Domenico; Glege, Frank; Gomez-Reino Garrido, Robert; Gouzevitch, Maxime; Govoni, Pietro; Gowdy, Stephen; Guiducci, Luigi; Hansen, Magnus; Hartl, Christian; Harvey, John; Hegeman, Jeroen; Hegner, Benedikt; Hoffmann, Hans Falk; Honma, Alan; Innocente, Vincenzo; Janot, Patrick; Kaadze, Ketino; Karavakis, Edward; Lecoq, Paul; Lourenco, Carlos; Maki, Tuula; Malberti, Martina; Malgeri, Luca; Mannelli, Marcello; Masetti, Lorenzo; Maurisset, Aurelie; Meijers, Frans; Mersi, Stefano; Meschi, Emilio; Moser, Roland; Mozer, Matthias Ulrich; Mulders, Martijn; Nesvold, Erik; Nguyen, Matthew; Orimoto, Toyoko; Orsini, Luciano; Perez, Emmanuelle; Petrilli, Achille; Pfeiffer, Andreas; Pierini, Maurizio; Pimiä, Martti; Piparo, Danilo; Polese, Giovanni; Racz, Attila; Rodrigues Antunes, Joao; Rolandi, Gigi; Rommerskirchen, Tanja; Rovere, Marco; Sakulin, Hannes; Schäfer, Christoph; Schwick, Christoph; Segoni, Ilaria; Sharma, Archana; Siegrist, Patrice; Simon, Michal; Sphicas, Paraskevas; Spiropulu, Maria; Stoye, Markus; Tropea, Paola; Tsirou, Andromachi; Vichoudis, Paschalis; Voutilainen, Mikko; Zeuner, Wolfram Dietrich; Bertl, Willi; Deiters, Konrad; Erdmann, Wolfram; Gabathuler, Kurt; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; König, Stefan; Kotlinski, Danek; Langenegger, Urs; Meier, Frank; Renker, Dieter; Rohe, Tilman; Sibille, Jennifer; Starodumov, Andrei; Bäni, Lukas; Bortignon, Pierluigi; Caminada, Lea; Chanon, Nicolas; Chen, Zhiling; Cittolin, Sergio; Dissertori, Günther; Dittmar, Michael; Eugster, Jürg; Freudenreich, Klaus; Grab, Christoph; Hintz, Wieland; Lecomte, Pierre; Lustermann, Werner; Marchica, Carmelo; Martinez Ruiz del Arbol, Pablo; Milenovic, Predrag; Moortgat, Filip; Nägeli, Christoph; Nef, Pascal; Nessi-Tedaldi, Francesca; Pape, Luc; Pauss, Felicitas; Punz, Thomas; Rizzi, Andrea; Ronga, Frederic Jean; Rossini, Marco; Sala, Leonardo; Sanchez, Ann - Karin; Sawley, Marie-Christine; Stieger, Benjamin; Tauscher, Ludwig; Thea, Alessandro; Theofilatos, Konstantinos; Treille, Daniel; Urscheler, Christina; Wallny, Rainer; Weber, Matthias; Wehrli, Lukas; Weng, Joanna; Aguilo, Ernest; Amsler, Claude; Chiochia, Vincenzo; De Visscher, Simon; Favaro, Carlotta; Ivova Rikova, Mirena; Millan Mejias, Barbara; Otiougova, Polina; Regenfus, Christian; Robmann, Peter; Schmidt, Alexander; Snoek, Hella; Chang, Yuan-Hann; Chen, Kuan-Hsin; Kuo, Chia-Ming; Li, Syue-Wei; Lin, Willis; Liu, Zong-Kai; Lu, Yun-Ju; Mekterovic, Darko; Volpe, Roberta; Wu, Jing-Han; Yu, Shin-Shan; Bartalini, Paolo; Chang, Paoti; Chang, You-Hao; Chang, Yu-Wei; Chao, Yuan; Chen, Kai-Feng; Hou, George Wei-Shu; Hsiung, Yee; Kao, Kai-Yi; Lei, Yeong-Jyi; Lu, Rong-Shyang; Shiu, Jing-Ge; Tzeng, Yeng-Ming; Wang, Minzu; Adiguzel, Aytul; Bakirci, Mustafa Numan; Cerci, Salim; Dozen, Candan; Dumanoglu, Isa; Eskut, Eda; Girgis, Semiray; Gokbulut, Gul; Hos, Ilknur; Kangal, Evrim Ersin; Kayis Topaksu, Aysel; Onengut, Gulsen; Ozdemir, Kadri; Ozturk, Sertac; Polatoz, Ayse; Sogut, Kenan; Sunar Cerci, Deniz; Tali, Bayram; Topakli, Huseyin; Uzun, Dilber; Vergili, Latife Nukhet; Vergili, Mehmet; Akin, Ilina Vasileva; Aliev, Takhmasib; Bilin, Bugra; Bilmis, Selcuk; Deniz, Muhammed; Gamsizkan, Halil; Guler, Ali Murat; Ocalan, Kadir; Ozpineci, Altug; Serin, Meltem; Sever, Ramazan; Surat, Ugur Emrah; Yildirim, Eda; Zeyrek, Mehmet; Deliomeroglu, Mehmet; Demir, Durmus; Gülmez, Erhan; Isildak, Bora; Kaya, Mithat; Kaya, Ozlem; Özbek, Melih; Ozkorucuklu, Suat; Sonmez, Nasuf; Levchuk, Leonid; Bostock, Francis; Brooke, James John; Cheng, Teh Lee; Clement, Emyr; Cussans, David; Frazier, Robert; Goldstein, Joel; Grimes, Mark; Hansen, Maria; Hartley, Dominic; Heath, Greg P; Heath, Helen F; Kreczko, Lukasz; Metson, Simon; Newbold, Dave M; Nirunpong, Kachanon; Poll, Anthony; Senkin, Sergey; Smith, Vincent J; Ward, Simon; Basso, Lorenzo; Bell, Ken W; Belyaev, Alexander; Brew, Christopher; Brown, Robert M; Camanzi, Barbara; Cockerill, David JA; Coughlan, John A; Harder, Kristian; Harper, Sam; Jackson, James; Kennedy, Bruce W; Olaiya, Emmanuel; Petyt, David; Radburn-Smith, Benjamin Charles; Shepherd-Themistocleous, Claire; Tomalin, Ian R; Womersley, William John; Worm, Steven; Bainbridge, Robert; Ball, Gordon; Ballin, Jamie; Beuselinck, Raymond; Buchmuller, Oliver; Colling, David; Cripps, Nicholas; Cutajar, Michael; Davies, Gavin; Della Negra, Michel; Ferguson, William; Fulcher, Jonathan; Futyan, David; Gilbert, Andrew; Guneratne Bryer, Arlo; Hall, Geoffrey; Hatherell, Zoe; Hays, Jonathan; Iles, Gregory; Jarvis, Martyn; Karapostoli, Georgia; Lyons, Louis; MacEvoy, Barry C; Magnan, Anne-Marie; Marrouche, Jad; Mathias, Bryn; Nandi, Robin; Nash, Jordan; Nikitenko, Alexander; Papageorgiou, Anastasios; Pesaresi, Mark; Petridis, Konstantinos; Pioppi, Michele; Raymond, David Mark; Rogerson, Samuel; Rompotis, Nikolaos; Rose, Andrew; Ryan, Matthew John; Seez, Christopher; Sharp, Peter; Sparrow, Alex; Tapper, Alexander; Tourneur, Stephane; Vazquez Acosta, Monica; Virdee, Tejinder; Wakefield, Stuart; Wardle, Nicholas; Wardrope, David; Whyntie, Tom; Barrett, Matthew; Chadwick, Matthew; Cole, Joanne; Hobson, Peter R; Khan, Akram; Kyberd, Paul; Leslie, Dawn; Martin, William; Reid, Ivan; Teodorescu, Liliana; Hatakeyama, Kenichi; Liu, Hongxuan; Henderson, Conor; Bose, Tulika; Carrera Jarrin, Edgar; Fantasia, Cory; Heister, Arno; St John, Jason; Lawson, Philip; Lazic, Dragoslav; Rohlf, James; Sperka, David; Sulak, Lawrence; Avetisyan, Aram; Bhattacharya, Saptaparna; Chou, John Paul; Cutts, David; Ferapontov, Alexey; Heintz, Ulrich; Jabeen, Shabnam; Kukartsev, Gennadiy; Landsberg, Greg; Luk, Michael; Narain, Meenakshi; Nguyen, Duong; Segala, Michael; Sinthuprasith, Tutanon; Speer, Thomas; Tsang, Ka Vang; Breedon, Richard; Calderon De La Barca Sanchez, Manuel; 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Traczyk, Piotr; Veverka, Jan; Wilkinson, Richard; Yang, Yong; Zhu, Ren-Yuan; Akgun, Bora; Carroll, Ryan; Ferguson, Thomas; Iiyama, Yutaro; Jang, Dong Wook; Jun, Soon Yung; Liu, Yueh-Feng; Paulini, Manfred; Russ, James; Vogel, Helmut; Vorobiev, Igor; Cumalat, John Perry; Dinardo, Mauro Emanuele; Drell, Brian Robert; Edelmaier, Christopher; Ford, William T; Gaz, Alessandro; Heyburn, Bernadette; Luiggi Lopez, Eduardo; Nauenberg, Uriel; Smith, James; Stenson, Kevin; Ulmer, Keith; Wagner, Stephen Robert; Zang, Shi-Lei; Agostino, Lorenzo; Alexander, James; Cassel, David; Chatterjee, Avishek; Das, Souvik; Eggert, Nicholas; Gibbons, Lawrence Kent; Heltsley, Brian; Hopkins, Walter; Khukhunaishvili, Aleko; Kreis, Benjamin; Nicolas Kaufman, Gala; Patterson, Juliet Ritchie; Puigh, Darren; Ryd, Anders; Salvati, Emmanuele; Shi, Xin; Sun, Werner; Teo, Wee Don; Thom, Julia; Thompson, Joshua; Vaughan, Jennifer; Weng, Yao; Winstrom, Lucas; Wittich, Peter; Biselli, Angela; Cirino, Guy; Winn, Dave; Abdullin, Salavat; Albrow, Michael; Anderson, Jacob; Apollinari, Giorgio; Atac, Muzaffer; Bakken, Jon Alan; Banerjee, Sunanda; Bauerdick, Lothar AT; Beretvas, Andrew; Berryhill, Jeffrey; Bhat, Pushpalatha C; Bloch, Ingo; Borcherding, Frederick; Burkett, Kevin; Butler, Joel Nathan; Chetluru, Vasundhara; Cheung, Harry; Chlebana, Frank; Cihangir, Selcuk; Cooper, William; Eartly, David P; Elvira, Victor Daniel; Esen, Selda; Fisk, Ian; Freeman, Jim; Gao, Yanyan; Gottschalk, Erik; Green, Dan; Gunthoti, Kranti; Gutsche, Oliver; Hanlon, Jim; Harris, Robert M; Hirschauer, James; Hooberman, Benjamin; Jensen, Hans; Johnson, Marvin; Joshi, Umesh; Khatiwada, Rakshya; Klima, Boaz; Kousouris, Konstantinos; Kunori, Shuichi; Kwan, Simon; Leonidopoulos, Christos; Limon, Peter; Lincoln, Don; Lipton, Ron; Lykken, Joseph; Maeshima, Kaori; Marraffino, John Michael; Mason, David; McBride, Patricia; Miao, Ting; Mishra, Kalanand; Mrenna, Stephen; Musienko, Yuri; Newman-Holmes, Catherine; O'Dell, Vivian; Pordes, Ruth; Prokofyev, Oleg; Saoulidou, Niki; Sexton-Kennedy, Elizabeth; Sharma, Seema; Spalding, William J; Spiegel, Leonard; Tan, Ping; Taylor, Lucas; Tkaczyk, Slawek; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vidal, Richard; Whitmore, Juliana; Wu, Weimin; Yang, Fan; Yumiceva, Francisco; Yun, Jae Chul; Acosta, Darin; Avery, Paul; Bourilkov, Dimitri; Chen, Mingshui; De Gruttola, Michele; Di Giovanni, Gian Piero; Dobur, Didar; Drozdetskiy, Alexey; Field, Richard D; Fisher, Matthew; Fu, Yu; Furic, Ivan-Kresimir; Gartner, Joseph; Kim, Bockjoo; Konigsberg, Jacobo; Korytov, Andrey; Kropivnitskaya, Anna; Kypreos, Theodore; Matchev, Konstantin; Mitselmakher, Guenakh; Muniz, Lana; Prescott, Craig; Remington, Ronald; Schmitt, Michael Houston; Scurlock, Bobby; Sellers, Paul; Skhirtladze, Nikoloz; Snowball, Matthew; Wang, Dayong; Yelton, John; Zakaria, Mohammed; Ceron, Cristobal; Gaultney, Vanessa; Kramer, Laird; Lebolo, Luis Miguel; Linn, Stephan; Markowitz, Pete; Martinez, German; Mesa, Dalgis; Rodriguez, Jorge Luis; Adams, Todd; Askew, Andrew; Bochenek, Joseph; Chen, Jie; Diamond, Brendan; Gleyzer, Sergei V; Haas, Jeff; Hagopian, Sharon; Hagopian, Vasken; Jenkins, Merrill; Johnson, Kurtis F; Prosper, Harrison; Quertenmont, Loic; Sekmen, Sezen; Veeraraghavan, Venkatesh; Baarmand, Marc M; Dorney, Brian; Guragain, Samir; Hohlmann, Marcus; Kalakhety, Himali; Ralich, Robert; Vodopiyanov, Igor; Adams, Mark Raymond; Anghel, Ioana Maria; Apanasevich, Leonard; Bai, Yuting; Bazterra, Victor Eduardo; Betts, Russell Richard; Callner, Jeremy; Cavanaugh, Richard; Dragoiu, Cosmin; Gauthier, Lucie; Gerber, Cecilia Elena; Hamdan, Saleh; Hofman, David Jonathan; Khalatyan, Samvel; Kunde, Gerd J; Lacroix, Florent; Malek, Magdalena; O'Brien, Christine; Silvestre, Catherine; Smoron, Agata; Strom, Derek; Varelas, Nikos; Akgun, Ugur; Albayrak, Elif Asli; Bilki, Burak; Clarida, Warren; Duru, Firdevs; Lae, Chung Khim; McCliment, Edward; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Newsom, Charles Ray; Norbeck, Edwin; Olson, Jonathan; Onel, Yasar; Ozok, Ferhat; Sen, Sercan; Wetzel, James; Yetkin, Taylan; Yi, Kai; Barnett, Bruce Arnold; Blumenfeld, Barry; Bonato, Alessio; Eskew, Christopher; Fehling, David; Giurgiu, Gavril; Gritsan, Andrei; Guo, Zijin; Hu, Guofan; Maksimovic, Petar; Rappoccio, Salvatore; Swartz, Morris; Tran, Nhan Viet; Whitbeck, Andrew; Baringer, Philip; Bean, Alice; Benelli, Gabriele; Grachov, Oleg; Kenny Iii, Raymond Patrick; Murray, Michael; Noonan, Daniel; Sanders, Stephen; Wood, Jeffrey Scott; Zhukova, Victoria; Barfuss, Anne-fleur; Bolton, Tim; Chakaberia, Irakli; Ivanov, Andrew; Khalil, Sadia; Makouski, Mikhail; Maravin, Yurii; Shrestha, Shruti; Svintradze, Irakli; Wan, Zongru; Gronberg, Jeffrey; Lange, David; Wright, Douglas; Baden, Drew; Boutemeur, Madjid; Eno, Sarah Catherine; Ferencek, Dinko; Gomez, Jaime; Hadley, Nicholas John; Kellogg, Richard G; Kirn, Malina; Lu, Ying; Mignerey, Alice; Rossato, Kenneth; Rumerio, Paolo; Santanastasio, Francesco; Skuja, Andris; Temple, Jeffrey; Tonjes, Marguerite; Tonwar, Suresh C; Twedt, Elizabeth; Alver, Burak; Bauer, Gerry; Bendavid, Joshua; Busza, Wit; Butz, Erik; Cali, Ivan Amos; Chan, Matthew; Dutta, Valentina; Everaerts, Pieter; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Hahn, Kristan Allan; Harris, Philip; Kim, Yongsun; Klute, Markus; Lee, Yen-Jie; Li, Wei; Loizides, Constantinos; Luckey, Paul David; Ma, Teng; Nahn, Steve; Paus, Christoph; Ralph, Duncan; Roland, Christof; Roland, Gunther; Rudolph, Matthew; Stephans, George; Stöckli, Fabian; Sumorok, Konstanty; Sung, Kevin; Wenger, Edward Allen; Xie, Si; Yang, Mingming; Yilmaz, Yetkin; Yoon, Sungho; Zanetti, Marco; Cooper, Seth; Cushman, Priscilla; Dahmes, Bryan; De Benedetti, Abraham; Dudero, Phillip Russell; Franzoni, Giovanni; Haupt, Jason; Klapoetke, Kevin; Kubota, Yuichi; Mans, Jeremy; Rekovic, Vladimir; Rusack, Roger; Sasseville, Michael; Singovsky, Alexander; Tambe, Norbert; Cremaldi, Lucien Marcus; Godang, Romulus; Kroeger, Rob; Perera, Lalith; Rahmat, Rahmat; Sanders, David A; Summers, Don; Bloom, Kenneth; Bose, Suvadeep; Butt, Jamila; Claes, Daniel R; Dominguez, Aaron; Eads, Michael; Keller, Jason; Kelly, Tony; Kravchenko, Ilya; Lazo-Flores, Jose; Malbouisson, Helena; Malik, Sudhir; Snow, Gregory R; Baur, Ulrich; Godshalk, Andrew; Iashvili, Ia; Jain, Supriya; Kharchilava, Avto; Kumar, Ashish; Shipkowski, Simon Peter; Smith, Kenneth; Alverson, George; Barberis, Emanuela; Baumgartel, Darin; Boeriu, Oana; Chasco, Matthew; Reucroft, Steve; Swain, John; Trocino, Daniele; Wood, Darien; Zhang, Jinzhong; Anastassov, Anton; Kubik, Andrew; Odell, Nathaniel; Ofierzynski, Radoslaw Adrian; Pollack, Brian; Pozdnyakov, Andrey; Schmitt, Michael Henry; Stoynev, Stoyan; Velasco, Mayda; Won, Steven; Antonelli, Louis; Berry, Douglas; Brinkerhoff, Andrew; Hildreth, Michael; Jessop, Colin; Karmgard, Daniel John; Kolb, Jeff; Kolberg, Ted; Lannon, Kevin; Luo, Wuming; Lynch, Sean; Marinelli, Nancy; Morse, David Michael; Pearson, Tessa; Ruchti, Randy; Slaunwhite, Jason; Valls, Nil; Wayne, Mitchell; Ziegler, Jill; Bylsma, Ben; Durkin, Lloyd Stanley; Gu, Jianhui; Hill, Christopher; Killewald, Phillip; Kotov, Khristian; Ling, Ta-Yung; Rodenburg, Marissa; Williams, Grayson; Adam, Nadia; Berry, Edmund; Elmer, Peter; Gerbaudo, Davide; Halyo, Valerie; Hebda, Philip; Hunt, Adam; Jones, John; Laird, Edward; Lopes Pegna, David; Marlow, Daniel; Medvedeva, Tatiana; Mooney, Michael; Olsen, James; Piroué, Pierre; Quan, Xiaohang; Saka, Halil; Stickland, David; Tully, Christopher; Werner, Jeremy Scott; Zuranski, Andrzej; Acosta, Jhon Gabriel; Huang, Xing Tao; Lopez, Angel; Mendez, Hector; Oliveros, Sandra; Ramirez Vargas, Juan Eduardo; Zatserklyaniy, Andriy; Alagoz, Enver; Barnes, Virgil E; Bolla, Gino; Borrello, Laura; Bortoletto, Daniela; Everett, Adam; Garfinkel, Arthur F; Gutay, Laszlo; Hu, Zhen; Jones, Matthew; Koybasi, Ozhan; Kress, Matthew; Laasanen, Alvin T; Leonardo, Nuno; Liu, Chang; Maroussov, Vassili; Merkel, Petra; Miller, David Harry; Neumeister, Norbert; Shipsey, Ian; Silvers, David; Svyatkovskiy, Alexey; Yoo, Hwi Dong; Zablocki, Jakub; Zheng, Yu; Jindal, Pratima; Parashar, Neeti; Boulahouache, Chaouki; Cuplov, Vesna; Ecklund, Karl Matthew; Geurts, Frank JM; Padley, Brian Paul; Redjimi, Radia; Roberts, Jay; Zabel, James; Betchart, Burton; Bodek, Arie; Chung, Yeon Sei; Covarelli, Roberto; de Barbaro, Pawel; Demina, Regina; Eshaq, Yossof; Flacher, Henning; Garcia-Bellido, Aran; Goldenzweig, Pablo; Gotra, Yury; Han, Jiyeon; Harel, Amnon; Miner, Daniel Carl; Orbaker, Douglas; Petrillo, Gianluca; Vishnevskiy, Dmitry; Zielinski, Marek; Bhatti, Anwar; Ciesielski, Robert; Demortier, Luc; Goulianos, Konstantin; Lungu, Gheorghe; Malik, Sarah; Mesropian, Christina; Yan, Ming; Atramentov, Oleksiy; Barker, Anthony; Duggan, Daniel; Gershtein, Yuri; Gray, Richard; Halkiadakis, Eva; Hidas, Dean; Hits, Dmitry; Lath, Amitabh; Panwalkar, Shruti; Patel, Rishi; Richards, Alan; Rose, Keith; Schnetzer, Steve; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Cerizza, Giordano; Hollingsworth, Matthew; Spanier, Stefan; Yang, Zong-Chang; York, Andrew; Eusebi, Ricardo; Flanagan, Will; Gilmore, Jason; Gurrola, Alfredo; Kamon, Teruki; Khotilovich, Vadim; Montalvo, Roy; Osipenkov, Ilya; Pakhotin, Yuriy; Pivarski, James; Safonov, Alexei; Sengupta, Sinjini; Tatarinov, Aysen; Toback, David; Weinberger, Michael; Akchurin, Nural; Bardak, Cemile; Damgov, Jordan; Jeong, Chiyoung; Kovitanggoon, Kittikul; Lee, Sung Won; Mane, Poonam; Roh, Youn; Sill, Alan; Volobouev, Igor; Wigmans, Richard; Yazgan, Efe; Appelt, Eric; Brownson, Eric; Engh, Daniel; Florez, Carlos; Gabella, William; Issah, Michael; Johns, Willard; Kurt, Pelin; Maguire, Charles; Melo, Andrew; Sheldon, Paul; Snook, Benjamin; Tuo, Shengquan; Velkovska, Julia; Arenton, Michael Wayne; Balazs, Michael; Boutle, Sarah; Cox, Bradley; Francis, Brian; Hirosky, Robert; Ledovskoy, Alexander; Lin, Chuanzhe; Neu, Christopher; Yohay, Rachel; Gollapinni, Sowjanya; Harr, Robert; Karchin, Paul Edmund; Lamichhane, Pramod; Mattson, Mark; Milstène, Caroline; Sakharov, Alexandre; Anderson, Michael; Bachtis, Michail; Bellinger, James Nugent; Carlsmith, Duncan; Dasu, Sridhara; Efron, Jonathan; Flood, Kevin; Gray, Lindsey; Grogg, Kira Suzanne; Grothe, Monika; Hall-Wilton, Richard; Herndon, Matthew; Hervé, Alain; Klabbers, Pamela; Klukas, Jeffrey; Lanaro, Armando; Lazaridis, Christos; Leonard, Jessica; Loveless, Richard; Mohapatra, Ajit; Palmonari, Francesco; Reeder, Don; Ross, Ian; Savin, Alexander; Smith, Wesley H; Swanson, Joshua; Weinberg, Marc
2013-07-16
A search for pair-production of first generation scalar leptoquarks is performed in the final state containing an electron, a neutrino, and at least two jets using proton-proton collision data at sqrt(s)=7 TeV. The data were collected by the CMS detector at the LHC, corresponding to an integrated luminosity of 36 inverse picobarns. The number of observed events is in good agreement with the predictions for standard model processes. Prior CMS results in the dielectron channel are combined with this electron+neutrino search. A 95% confidence level combined lower limit is set on the mass of a first generation scalar leptoquark at 340 GeV for beta=0.5, where beta is the branching fraction of the leptoquark to an electron and a quark. These results represent the most stringent direct limits to date for values of beta greater than 0.05.
Quantum Gravity Effects in Scalar, Vector and Tensor Field Propagation
Dutta, Anindita
Quantum theory of gravity deals with the physics of the gravitational field at Planck length scale (10-35 m). Even though it is experimentally hard to reach the Planck length scale, on can look for evidence of quantum gravity that is detectable in astrophysics. In this thesis, we try to find effects of loop quantum gravity corrections on observable phenomena. We show that the quantum fluctuation strain for LIGO data would be 10 -125 on the Earth. Th correction is, however, substantial near the black hole horizon. We discuss the effect of this for scalar field propagation followed by vector and tensor fields. For the scalar field, the correction introduces a new asymmetry; for the vector field, we found a new perturbation solution and for the tensor field, we found the corrected Einstein equations which are yet to solve. These will affect phenomena like Hawking radiation, black hole entropy and gravitational waves.
Extension of warm inflation to non-canonical scalar fields
Zhang, Xiao-Min
2014-01-01
We extend the warm inflationary scenario to the case of the non-canonical scalar fields. The equation of motion and the other basic equations of this new scenario are obtained. The Hubble damped term is enhanced in non-canonical inflation. A linear stability analysis is performed to give the proper slow roll conditions in warm non-canonical inflation. We study the density fluctuations in the new picture and obtain an approximate analytic expression of the power spectrum. The energy scale at the horizon crossing is depressed by both non-canonical effect and thermal effect, so does the tensor-to-scalar ratio. Besides the synergy, the non-canonical effect and the thermal effect are competing in the case of the warm non-canonical inflation.
Symmetric digit sets for elliptic curve scalar multiplication without precomputation.
Heuberger, Clemens; Mazzoli, Michela
2014-08-28
We describe a method to perform scalar multiplication on two classes of ordinary elliptic curves, namely [Formula: see text] in prime characteristic [Formula: see text], and [Formula: see text] in prime characteristic [Formula: see text]. On these curves, the 4-th and 6-th roots of unity act as (computationally efficient) endomorphisms. In order to optimise the scalar multiplication, we consider a width- w -NAF (Non-Adjacent Form) digit expansion of positive integers to the complex base of τ , where τ is a zero of the characteristic polynomial [Formula: see text] of the Frobenius endomorphism associated to the curve. We provide a precomputationless algorithm by means of a convenient factorisation of the unit group of residue classes modulo τ in the endomorphism ring, whereby we construct a digit set consisting of powers of subgroup generators, which are chosen as efficient endomorphisms of the curve.
Interpreting Dynamically-Averaged Scalar Couplings in Proteins
DEFF Research Database (Denmark)
Lindorff-Larsen, Kresten; Best, Robert B.; Vendruscolo, Michele
2005-01-01
The experimental determination of scalar three-bond coupling constants represents a powerful method to probe both the structure and dynamics of proteins. The detailed structural interpretation of such coupling constants is usually based on Karplus relationships, which allow the measured couplings...... present a method to derive such parameters that uses ensembles of conformations determined through dynamic-ensemble refinement - a method that provides structural ensembles that simultaneously represent both the structure and the associated dynamics of a protein....
Fractal dimension crossovers in turbulent passive scalar signals
Grossmann, S; Grossmann, Siegfried; Lohse, Detlef
1993-01-01
Abstract: The fractal dimension $\\delta_g^{(1)}$ of turbulent passive scalar signals is calculated from the fluid dynamical equation. $\\delta_g^{(1)}$ depends on the scale. For small Prandtl (or Schmidt) number $Pr 1$ one gets a third, intermediate range in which the signal is extremely wrinkled and has $D_\\theta(r)$ has a plateau. We calculate the $Pr$-dependence of the crossovers. Comparison with a numerical reduced wave vector set calculation gives good agreement with our predictions.
Minimal scalar-less matter-coupled supergravity
Energy Technology Data Exchange (ETDEWEB)
Dall' Agata, Gianguido, E-mail: dallagat@pd.infn.it [Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, I-35131 Padova (Italy); INFN, Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Centre de Physique Théorique, École Polytechnique, CNRS, Université Paris-Saclay, F-91128 Palaiseau (France); Ferrara, Sergio [Theory Unit, Physics Department, CERN, CH-1211 Geneva 23 (Switzerland); INFN, Laboratori Nazionali di Frascati, Via Enrico Fermi 40, I-00044 Frascati (Italy); Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095-1547 (United States); Zwirner, Fabio [Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, I-35131 Padova (Italy); INFN, Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Theory Unit, Physics Department, CERN, CH-1211 Geneva 23 (Switzerland)
2016-01-10
We build the minimal supergravity model where the nilpotent chiral goldstino superfield is coupled to a chiral matter superfield, realising a different non-linear representation through a mixed nilpotency constraint. The model describes the spontaneous breaking of local supersymmetry in the presence of a generically massive Majorana fermion, but in the absence of elementary scalars. The sign and the size of the cosmological constant, the spectrum and the four-fermion interactions are controlled by suitable parameters.
Quenched scalar-meson correlator with domain wall fermions
Energy Technology Data Exchange (ETDEWEB)
Prelovsek, S.; Orginos, K
2003-05-01
We study the q-barq singlet and non-singlet scalar-meson masses using domain wall fermions and the quenched approximation. The singlet mass is found to be smaller than the non-singlet mass and indicates that the lowest singlet meson state could be lighter than 1 GeV. The two-point functions for very small quark masses are compared with expectations from the small-volume chiral perturbation theory and the presence of fermionic zero modes.
Insight into the scalar mesons from a lattice calculation
Energy Technology Data Exchange (ETDEWEB)
Alford, Mark E-mail: alford@mit.edu; Jaffe, R.L
2000-07-03
We study the possibility that the light scalar mesons are q-bar{sup 2}q{sup 2} states rather than q-barq . We perform a lattice QCD calculation of pseudoscalar meson scattering amplitudes, ignoring quark loops and quark annihilation, and find indications that for sufficiently heavy quarks there is a stable four-quark bound state with J{sup PC}=0{sup ++} and non-exotic flavor quantum numbers.
Scaling symmetry and scalar hairy Lifshitz black holes
Energy Technology Data Exchange (ETDEWEB)
Hyun, Seungjoon [Department of Physics, College of Science, Yonsei University, Seoul 120-749 (Korea, Republic of); Jeong, Jaehoon [Institute of Theoretical Physics, Aristotle University of Thessaloniki, 54124, Thessaloniki (Greece); Park, Sang-A; Yi, Sang-Heon [Department of Physics, College of Science, Yonsei University, Seoul 120-749 (Korea, Republic of)
2015-10-15
By utilizing the scaling symmetry of the reduced action for planar black holes, we obtain the corresponding conserved charge. We use the conserved charge to find the generalized Smarr relation of static hairy planar black holes in various dimensions. Our results not only reproduce the relation in the various known cases but also give the new relation in the Lifshitz planar black holes with the scalar hair.
Polchinski ERG equation and 2D scalar field theory
Kubyshin, Yuri; Neves, Rui; Potting, Robertus
1998-01-01
We investigate a $Z_2$-symmetric scalar field theory in two dimensions using the Polchinski exact renormalization group equation expanded to second order in the derivative expansion. We find preliminary evidence that the Polchinski equation is able to describe the non-perturbative infinite set of fixed points in the theory space, corresponding to the minimal unitary series of 2D conformal field theories. We compute the anomalous scaling dimension $\\eta$ and the correlation l...
Minimal scalar-less matter-coupled supergravity
Directory of Open Access Journals (Sweden)
Gianguido Dall'Agata
2016-01-01
Full Text Available We build the minimal supergravity model where the nilpotent chiral goldstino superfield is coupled to a chiral matter superfield, realising a different non-linear representation through a mixed nilpotency constraint. The model describes the spontaneous breaking of local supersymmetry in the presence of a generically massive Majorana fermion, but in the absence of elementary scalars. The sign and the size of the cosmological constant, the spectrum and the four-fermion interactions are controlled by suitable parameters.
Local transformations of units in scalar-tensor cosmology
Energy Technology Data Exchange (ETDEWEB)
Catena, R. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Pietroni, M. [INFN, Sezione di Padova (Italy); Scarabello, L. [INFN, Sezione di Padova (Italy)]|[Padua Univ. (Italy). Dipt. di Fisica
2006-10-15
The physical equivalence of Einstein and Jordan frame in Scalar Tensor theories has been explained by Dicke in 1962: they are related by a local transformation of units. We discuss this point in a cosmological framework. Our main result is the construction of a formalism in which all the physical observables are frame-invariant. The application of this approach to CMB codes is at present under analysis. (orig.)
Bounded scalar perturbations in bouncing brane world cosmologies
Maier, Rodrigo; Pace, Francesco; Soares, Ivano Damião
2013-11-01
We examine the dynamics of scalar perturbations in closed Friedmann-Lemaître-Robertson-Walker universes in the framework of brane world theory with a timelike extra dimension. In this scenario, the unperturbed Friedmann equations contain additional terms arising from the bulk-brane interaction that implement nonsingular bounces in the models with a cosmological constant and noninteracting perfect fluids. The structure of the phase space of the models allows for two basic configurations, namely, one bounce solutions and eternal universes. Assuming that the matter content of the model is given by dust and radiation, we derive the dynamical field equations for scalar hydrodynamical perturbations considering either a conformally flat (de Sitter) bulk or a perturbed bulk. The dynamical system built with these equations is extremely involved. Nevertheless, in this paper we perform a numerical analysis which can shed some light on the study of cosmological scalar perturbations in bouncing brane world models. From a mathematical point of view we show that although the bounce enhances the amplitudes of scalar perturbations for one bounce models in the case of a de Sitter bulk, the amplitudes of the perturbations remain sufficiently small and bounded relative to the background values up to a certain scale. For one bounce models in the case of a perturbed bulk the amplitudes of all perturbations (apart from the Weyl fluid energy density) remain sufficiently small and bounded relative to the background values for any scale of the perturbations. We also discuss and compare the stability and bounded behavior of the perturbations in the late accelerated phase of one bounce solutions. For eternal universes we argue that some of these features are maintained only for early times (typically of the order of the first bounce). In this sense we show that eternal solutions are highly unstable configurations considering the background model of this paper.
Higgs particles interacting via a scalar Dark Matter field
Directory of Open Access Journals (Sweden)
Bhattacharya Yajnavalkya
2016-01-01
Full Text Available We study a system of two Higgs particles, interacting via a scalar Dark Matter mediating field. The variational method in the Hamiltonian formalism of QFT is used to derive relativistic wave equations for the two-Higgs system, using a truncated Fock-space trial state. Approximate solutions of the two-body equations are used to examine the existence of Higgs bound states.
Analysis of scalar dissipation in terms of vorticity geometry in isotropic turbulence
Gonzalez, Michel
2016-01-01
The mechanisms promoting scalar dissipation through scalar gradient production are scrutinized in terms of vorticity alignment with respect to strain principal axes. For that purpose, a stochastic Lagrangian model for the velocity gradient tensor and the scalar gradient vector is used. The model results show that the major part of scalar dissipation occurs for stretched vorticity, namely when the vorticity vector aligns with the extensional and intermediate strain eigenvectors. More specifically, it appears that the mean scalar dissipation is well represented by the sample defined by alignment with the extensional strain, while the most intense scalar dissipation is promoted by the set of events for which vorticity aligns with the intermediate strain. This difference is explained by rather subtle mechanisms involving the statistics of both the strain intensities and the scalar gradient alignment resulting from these special alignments of vorticity. The analysis allowing for the local flow structure confirms t...
Constraints from high redshift supernovae upon scalar field cosmologies
Energy Technology Data Exchange (ETDEWEB)
Frieman, J.A. [NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, Illinois60510 (United States)]|[Department of Astronomy and Astrophysics, University of Chicago, Chicago, Illinois60637 (United States); Waga, I. [Universidade Federal do Rio de Janeiro, Instituto de Fisica, Rio de Janeiro, RJ, 21945-970 (Brazil)
1998-04-01
Recent observations of high-redshift type Ia supernovae have placed stringent constraints on the cosmological constant {Lambda}. We explore the implications of these SNe observations for cosmological models in which a classically evolving scalar field currently dominates the energy density of the Universe. Such models have been shown to share the advantages of {Lambda} models: compatibility with the spatial flatness predicted by inflation; a Universe older than the standard Einstein{endash}de Sitter model; and, combined with cold dark matter, predictions for large-scale structure formation in good agreement with data from galaxy surveys. Compared to the cosmological constant, these scalar field models are consistent with the SNe observations for a lower matter density, {Omega}{sub m0}{approximately}0.2, and a higher age, H{sub 0}t{sub 0}{approx_gt}1. Combined with the fact that scalar field models imprint a distinctive signature on the cosmic microwave background anisotropy, they remain currently viable and should be testable in the near future. {copyright} {ital 1998} {ital The American Physical Society}
Scalar dissipation rates in non-conservative transport systems
Engdahl, Nicholas B.; Ginn, Timothy R.; Fogg, Graham E.
2013-06-01
This work considers how the inferred mixing state of diffusive and advective-diffusive systems will vary over time when the solute masses are not constant over time. We develop a number of tools that allow the scalar dissipation rate to be used as a mixing measure in these systems without calculating local concentration gradients. The behavior of dissipation rates is investigated for single and multi-component kinetic reactions and a commonly studied equilibrium reaction. The scalar dissipation rate of a tracer experiencing first-order decay can be determined exactly from the decay constant and the dissipation rate of a passive tracer, and the mixing rate of a conservative component is not the superposition of the solute specific mixing rates. We then show how the behavior of the scalar dissipation rate can be determined from a limited subset of an infinite domain. Corrections are derived for constant and time dependent limits of integration the latter is used to approximate dissipation rates in advective-diffusive systems. Several of the corrections exhibit similarities to the previous work on mixing, including non-Fickian mixing. This illustrates the importance of accounting for the effects that reaction systems or limited monitoring areas may have on the inferred mixing state.
Unifying darko-lepto-genesis with scalar triplet inflation
Arina, Chiara; Sahu, Narendra
2012-01-01
We present a scalar triplet extension of the standard model to unify the origin of inflation with neutrino mass, asymmetric dark matter and leptogenesis. In presence of non-minimal couplings to gravity the scalar triplet, mixed with the standard model Higgs, plays the role of inflaton in the early Universe, while its decay to SM Higgs, lepton and dark matter simultaneously generate an asymmetry in the visible and dark matter sectors. On the other hand, in the low energy effective theory the induced vacuum expectation value of the triplet gives sub-eV Majorana masses to active neutrinos. We investigate the model parameter space leading to successful inflation as well as the observed dark matter to baryon abundance. Assuming the standard model like Higgs mass to be at 125-126 GeV, we found that the mass scale of the scalar triplet to be ~ O(10^9) GeV and its trilinear coupling to doublet Higgs is ~ 0.09 so that it not only evades the possibility of having a metastable vacuum in the standard model, but also lead...