WorldWideScience
1

Search for electron EDM with laser cooled radioactive atom  

Science.gov (United States)

The permanent electric dipole moment (EDM) of the elementary particle has the sensitivity to the CP violation in the theories beyond the standard model (SM). The search for the EDM constitutes the stringent test to discriminate between the SM and beyond it. We plan to perform the electron EDM search by using the laser cooled francium (Fr) atom which has the largest enhancement factor of the electron EDM in the alkali atoms. In this paper, the present status of the laser cooled Fr factory that is being constructed at Cyclotron and Radioisotope Center (CYRIC), Tohoku University are reported.

Inoue, T.; Arikawa, H.; Ezure, S.; Harada, K.; Hayamizu, T.; Ishikawa, T.; Itoh, M.; Kato, T.; Kawamura, H.; Nataraj, H. S.; Sato, T.; Aoki, T.; Furukawa, T.; Hatakeyama, A.; Hatanaka, K.; Imai, K.; Murakami, T.; Shimizu, Y.; Wakasa, T.; Yoshida, H. P.; Sakemi, Y.

2013-05-01

2

Searching for the electron EDM in a storage ring  

International Nuclear Information System (INIS)

Searches for permanent electric dipole moments (EDM) of fundamental particles have been underway for more than 50 years with null results. Still, such searches are of great interest because EDMs arise from radiative corrections involving processes that violate parity and time-reversal symmetries, and through the CPT theorem, are sensitive to CP-violation. New models of physics beyond the standard model predict new sources of CP-violation leading to dramatically enhanced EDMs possibly within the reach of a new generation of experiments. We describe a new approach to electron EDM searches using molecular ions stored in a tabletop electrostatic storage ring. Molecular ions with long-lived paramagnetic states such as tungsten nitride WN+ can be injected and stored in larger numbers and with longer coherence times than competing experiments, leading to high sensitivity to an electron EDM. Systematic effects mimicking an EDM such as those due to motional magnetic fields and geometric phases are found not to limit the approach in the short term, and sensitivities of ?|de| ? 10-30 e·cm/day appear possible under conservative conditions.

3

Searching for the electron EDM in a storage ring  

Science.gov (United States)

Searches for permanent electric dipole moments (EDM) of fundamental particles have been underway for more than 50 years with null results. Still, such searches are of great interest because EDMs arise from radiative corrections involving processes that violate parity and time-reversal symmetries, and through the CPT theorem, are sensitive to CP-violation. New models of physics beyond the standard model predict new sources of CP-violation leading to dramatically enhanced EDMs possibly within the reach of a new generation of experiments. We describe a new approach to electron EDM searches using molecular ions stored in a tabletop electrostatic storage ring. Molecular ions with long-lived paramagnetic states such as tungsten nitride WN+ can be injected and stored in larger numbers and with longer coherence times than competing experiments, leading to high sensitivity to an electron EDM. Systematic effects mimicking an EDM such as those due to motional magnetic fields and geometric phases are found not to limit the approach in the short term, and sensitivities of ?|de| ? 10-30 e·cm/day appear possible under conservative conditions.

Kawall, D.

2011-05-01

4

Progress towards an electron EDM search using hafnium fluoride ions  

Science.gov (United States)

Trapped molecular ions provide large effective electric fields and long electron spin coherence times for the search for an electron electric dipole moment (eEDM). In particular, the ^3?1 state of HfF^+ has been proposed as a candidate for the eEDM search. To create HfF^+, we optically excite a supersonic beam of neutral HfF with two photons to an autoionizing state, and then perform laser-induced fluorescence to detect the state of the resultant HfF^+ ions. We report on our efforts to understand the autoionization process for efficient state preparation of HfF^+ ions, and on our general progress towards an eEDM measurement. This work is funded by the US National Science Foundation.

Loh, Huanqian; Grau, Matt; Yahn, Tyler; Field, Robert; Cornell, Eric

2011-06-01

5

Neutron-Electron EDM Correlations in Supersymmetry and Prospects for EDM Searches  

OpenAIRE

Motivated by recent progress in experimental techniques of electric dipole moment (EDM) measurements, we study correlations between the neutron and electron EDMs in common supersymmetric models. These include minimal supergravity (mSUGRA) with small CP phases, mSUGRA with a heavy SUSY spectrum, the decoupling scenario and split SUSY. In most cases, the electron and neutron EDMs are found to be observable in the next round of EDM experiments. They exhibit certain correlation ...

Abel, S.; Lebedev, O.

2005-01-01

6

Neutron-electron EDM correlations in supersymmetry and prospects for EDM searches  

International Nuclear Information System (INIS)

Motivated by recent progress in experimental techniques of electric dipole moment (EDM) measurements, we study correlations between the neutron and electron EDMs in common supersymmetric models. These include minimal supergravity (mSUGRA) with small CP phases, mSUGRA with a heavy SUSY spectrum, the decoupling scenario and split SUSY. In most cases, the electron and neutron EDMs are found to be observable in the next round of EDM experiments. They exhibit certain correlation patterns. For example, if dn ? 10-27 e cm is found, de is predicted to lie in the range 10-28-10-29 e cm

7

Neutron-electron EDM correlations in supersymmetry and prospects for EDM searches  

International Nuclear Information System (INIS)

Motivated by recent progress in experimental techniques of electric dipole moment (EDM) measurements, we study correlations between the neutron and electron EDMs in common supersymmetric models. These include minimal supergravity (mSUGRA) with small CP phases, mSUGRA with a heavy SUSY spectrum, the decoupling scenario and split SUSY. In most cases, the electron and neutron EDMs are found to be observable in the next round of EDM experiments. They exhibit certain correlation patterns. For example, if dn ? 10-27 e cm is found, de is predicted to lie in the range 10-28 - 10-29 e cm. (orig.)

8

A Search for the Electron EDM using Europium-Barium Titanates  

Science.gov (United States)

The discovery of a permanent electric dipole moment (EDM) of a fundamental particle would prove a great discovery in modern physics; such an EDM would violate two or three of the core symmetries of the fundamental forces of nature. Many models that go beyond the standard model of particle physics produce EDMs with magnitudes approaching the level detectable by the next generation of experiments. One possibility for such an experiment involves the use of a solid sample at low temperatures. In a paramagnetic material, the unpaired electrons, if they possess an EDM, can interact with the polarization of the sample and produce a magnetization that can be detected. This dissertation discusses an incarnation of such an experiment based on mixed europium-barium titanates. Such an experiment offers several advantages over other solid-state and atomic EDM searches including larger electron EDM induced interactions and the ability to measure without an applied electric field. This experiment has produced the world's best limit on the electron EDM to date from a solid sample, at |de| < 6.05 × 10-25 ecm (90% confidence limit). While this limit represents an improvement in the realm of solid-state experiments, it is not yet competitive with similar molecular and atomic experiments. However, there are many possibilities that could produce a superior solid-state experiment, and these will be discussed.

Eckel, Stephen P.

9

EDM searches  

Science.gov (United States)

Searches for permanent electric dipole moments of fundamental particles and systems with spin are among the most sensitive probes for physics beyond the Standard Model of particle physics. Many experimental efforts are under-way. This proceedings article presents a compilation of the presently ongoing experiments and those planned for the foreseeable future.

Kirch, Klaus

2013-10-01

10

Observable Electron EDM and Leptogenesis  

OpenAIRE

In the context of the minimal supersymmetric seesaw model, the CP-violating neutrino Yukawa couplings might induce an electron EDM. The same interactions may also be responsible for the generation of the observed baryon asymmetry of the Universe via leptogenesis. We identify in a model-independent way those patterns within the seesaw models which predict an electron EDM at a level probed by planned laboratory experiments and show that negative searches on \\tau-> e \\gamma dec...

Joaquim, F. R.; Masina, I.; Riotto, A.

2007-01-01

11

Electron EDM searches based on alkali or alkaline earth bearing molecules  

OpenAIRE

We introduce four new molecules -- YbRb, YbCs, YbSr$^+$, and YbBa$^+$ -- that may prove fruitful in experimental searches for the electric dipole moment (EDM) of the electron. These molecules can, in principle, be prepared at extremely low temperatures by photoassociating ultracold atoms, and therefore may present an advantage over molecular beam experiments. Here we discuss properties of these molecules and assess the effective electric fields they contribute to an electron...

Meyer, Edmund R.; Bohn, John L.

2009-01-01

12

Advanced Cold Molecule Electron EDM  

OpenAIRE

Measurement of a non-zero electric dipole moment (EDM) of the electron within a few orders of magnitude of the current best limit of |de| < 1.05 × 10?27?e?cm [1] would be an indication of physics beyond the Standard Model. The ACME Collaboration is searching for an electron EDM by performing a precision measurement of electron spin precession in the metastable H3?1 state of thorium monoxide (ThO) using a slow, cryogenic beam. We discuss the current status of the experiment. Based on ...

Campbell Wesley C.; Chan Cheong; DeMille David; Doyle John M.; Gabrielse Gerald; Gurevich Yulia V.; Hess Paul W.; Hutzler Nicholas R.; Kirilov Emil; Leary Brendon, O.; Petrik Elizabeth S.; Spaun Ben; Vutha Amar C.

2013-01-01

13

Advanced Cold Molecule Electron EDM  

CERN Document Server

Measurement of a non-zero electric dipole moment (EDM) of the electron within a few orders of magnitude of the current best limit of |d_e| < 1.05 e -27 e cm would be an indication of physics beyond the Standard Model. The ACME Collaboration is searching for an electron EDM by performing a precision measurement of electron spin precession in the metastable H state of thorium monoxide (ThO) using a slow, cryogenic beam. We discuss the current status of the experiment. Based on a data set acquired from 14 hours of running time over a period of 2 days, we have achieved a 1-sigma statistical uncertainty of 1 e -28 e cm/T^(1/2), where T is the running time in days.

Campbell, Wesley C; DeMille, David; Doyle, John M; Gabrielse, Gerald; Gurevich, Yulia V; Hess, Paul W; Hutzler, Nicholas R; Kirilov, Emil; OLeary, Brendon; Petrik, Elizabeth S; Spaun, Ben; Vutha, Amar C

2013-01-01

14

Advanced cold molecule electron EDM  

International Nuclear Information System (INIS)

Measurement of a non-zero electric dipole moment (EDM) of the electron within a few orders of magnitude of the current best limit of |de| -27 e x cm [1] would be an indication of physics beyond the Standard Model. The ACME Collaboration is searching for an electron EDM by performing a precision measurement of electron spin precession in the metastable H3?1 state of thorium monoxide (ThO) using a slow, cryogenic beam. We discuss the current status of the experiment. Based on a data set acquired from 14 hours of running time over a period of 2 days, we have achieved a 1-sigma statistical uncertainty of ?de = 1 x 10-28 e x cm/?T, where T is the running time in days. (authors)

15

Advanced cold molecule electron EDM  

Directory of Open Access Journals (Sweden)

Full Text Available Measurement of a non-zero electric dipole moment (EDM of the electron within a few orders of magnitude of the current best limit of |de| < 1.05 × 10?27?e?cm [1] would be an indication of physics beyond the Standard Model. The ACME Collaboration is searching for an electron EDM by performing a precision measurement of electron spin precession in the metastable H3?1 state of thorium monoxide (ThO using a slow, cryogenic beam. We discuss the current status of the experiment. Based on a data set acquired from 14 hours of running time over a period of 2 days, we have achieved a 1-sigma statistical uncertainty of ?de = 1 × 10?28?e?cm/?T, where T is the running time in days.

Campbell Wesley C.

2013-08-01

16

CKM benchmarks for electron EDM experiments  

OpenAIRE

All current experiments searching for an electron EDM d_e are performed with atoms and diatomic molecules. Motivated by significant recent progress in searches for an EDM-type signal in diatomic molecules with an uncompensated electron spin, we provide an estimate for the expected signal in the Standard Model due to the CKM phase. We find that the main contribution originates from the effective electron-nucleon operator $\\bar{e} i\\gamma_5 e \\bar{N}N$, induced by a combinatio...

Pospelov, Maxim; Ritz, Adam

2013-01-01

17

Search for permanent EDM using laser cooled Fr atoms  

Science.gov (United States)

The existence of a non-zero electric dipole moment (EDM) implies the violation of time reversal symmetry. As the time-reversal symmetry violation predicted by the Standard Model (SM) for the electron EDM is too small to be observed with current experimental techniques and any a non-zero EDM would indicate new physics beyond the SM. The tiny signal from the electron EDM is enhanced in the heavy atoms such as francium (Fr). We are constructing the laser-cooled Fr factory to search for the electron EDM.

Kawamura, Hirokazu; Aoki, T.; Arikawa, H.; Ezure, S.; Furukawa, T.; Harada, K.; Hatakeyama, A.; Hatanaka, K.; Hayamizu, T.; Imai, K.; Inoue, T.; Ishikawa, T.; Itoh, M.; Kato, T.; Murakami, T.; Nataraj, H. S.; Sato, T.; Shimizu, Y.; Wakasa, T.; Yoshida, H. P.; Sakemi, Y.

2013-03-01

18

An experimental search on the electron EDM based on solid-state techniques  

Science.gov (United States)

A discovery of a permanent electric dipole moment of the electron (eEDM) would provide crucial information about the nature of T-violation and imply new sources of CP-violation beyond the Standard Model. We are pursuing research that would improve the present experimental limit of the eEDM using a new technique in solid-state systems at 4K. The experiment uses a Gadolinium Gallium Garnet sample with a large magnetic response, which can be measured using the Superconducting Quantum Interference Device as the magnetometer. In this talk, I will discuss the progress to control the systematic effects, including the design and implementation of a 24-bit DAQ system with ultra-low level of channel crosstalk, and the control of the high voltage drift from the supply. With significant progress, finally we push the experimental limit of eEDM on the order of 10-25e cm under four days integration time of data, which is most sensitive results ever achieved using the solid state technique. In addition, the experiment is free of sources that could produce spurious signal at this level. Further enhancement of the eEDM sensitivity would require operating the experiment at sub-Kelvin temperatures.

Kim, Young Jin; Liu, Chen-Yu

2010-11-01

19

Probing the electron EDM with cold molecules  

International Nuclear Information System (INIS)

New elementary particle physics (beyond the standard model) is needed at the 1 TeV energy scale to understand the origin of mass and to explain why we see more matter than antimatter in the universe. This same new physics is expected to give the electron a permanent electric dipole (EDM) in the range of 10-26-10-30 e.cm. Thus the search for an electron EDM is the search for new particle physics. We are measuring the electron EDM using a beam of cold YbF. This molecule benefits from a large amplification of the electric dipole interaction, as do several other heavy, polar molecules (E.A. Hinds, Physica Scripta T70, 34 (1997)). In our experiment this amplification factor is roughly a million. The present version of our experiment has the statistical sensitivity to make a measurement at the level of a few times 10 -28 e.cm. and this is in progress. In the next version of the experiment, our 600 m/s beam will be decelerated to increase the coherence time. This, together with several other upgrades now in preparation, will give a further tenfold improvement in sensitivity. Ultimately it will be possible to trap YbF molecules, perhaps for several seconds. The combination of large enhancement factor together with long coherence time promises to bring the uncertainty in the electron EDM into the 10-30 range. I discuss the present status of this programme

20

Progress of the Jila Electron Edm Experiment  

Science.gov (United States)

Molecules can be advantageous for the search for the electron electric dipole moment (eEDM) due to the large effective electric field experienced by a bound, unpaired electron. Furthermore, the closely-spaced states of opposite parity make the molecules easy to polarize in the lab frame. The JILA eEDM experiment currently uses HfF^+ molecules in an ion trap to achieve long coherence times to reduce systematics. When an electric field is applied the eEDM signal is proportional to the shift in energy splitting between two Zeeman levels in a low-lying, metastable ^3?_1 state. We have previously shown efficient preparation of trapped HfF^+ molecules in the rovibronic ground state, X^1?^+(v=0,J=0). Here, we demonstrate coherent transfer of population from the ground state to the a^3?_1(v=0, J=1) state through an intermediate ^3?_{0+} state and efficient state read-out using photodissociation. In addition, we have begun to take spectroscopy data of the hyperfine and Zeeman structure of the eEDM science state in the presence of a rotating bias electric field and a magnetic field. A. E. Leanhardt et. al., Journal of Molecular Spectroscopy 270, 1-25 (2011). H. Loh et. al., Journal of Chemical Physics 135, 154308 (2011).

Loh, Huanqian; Cossel, Kevin C.; Grau, Matt; Gresh, Daniel N.; Ni, Kang-Kuen; Ye, Jun; Cornell, Eric A.

2013-06-01

21

Search for a permanent EDM using laser cooled radioactive atom  

Science.gov (United States)

The search for the electric-dipole moment (EDM) of laser-cooled francium (Fr) atoms could lead to a measurement for the electron EDM. It is predicted that the electron EDM would be enhanced by approximately three orders of magnitude in heavy atoms such as Fr. Laser-cooling and trapping techniques are expected to suppress statistical and systematic errors in precision measurements. The magneto-optical trap was achieved using stable rubidium in a developing factory of laser-cooled radioactive atoms. In light of the results from the rubidium experiments, we found that an upgrade of each apparatus is preferred for Fr trapping.

Kawamura, Hirokazu; Ando, S.; Aoki, T.; Arikawa, H.; Ezure, S.; Harada, K.; Hayamizu, T.; Inoue, T.; Ishikawa, T.; Itoh, M.; Kato, K.; Kato, T.; Nataraj, H. S.; Sato, T.; Uchiyama, A.; Aoki, T.; Furukawa, T.; Hatakeyama, A.; Hatanaka, K.; Imai, K.; Murakami, T.; Shimizu, Y.; Wakasa, T.; Yoshida, H. P.; Sakemi, Y.

2014-03-01

22

Search for a permanent EDM using laser cooled radioactive atom  

OpenAIRE

The search for the electric-dipole moment (EDM) of laser-cooled francium (Fr) atoms could lead to a measurement for the electron EDM. It is predicted that the electron EDM would be enhanced by approximately three orders of magnitude in heavy atoms such as Fr. Laser-cooling and trapping techniques are expected to suppress statistical and systematic errors in precision measurements. The magneto-optical trap was achieved using stable rubidium in a developing factory of laser-cooled radioactive a...

Kawamura Hirokazu; Ando S.; Arikawa H.; Ezure S.; Harada K.; Hayamizu T.; Inoue T; Ishikawa T; Itoh M; Kato K.; Kato T; Nataraj H.S.; Sato T.; Uchiyama A.; Aoki T

2014-01-01

23

Search for a permanent EDM using laser cooled radioactive atom  

Directory of Open Access Journals (Sweden)

Full Text Available The search for the electric-dipole moment (EDM of laser-cooled francium (Fr atoms could lead to a measurement for the electron EDM. It is predicted that the electron EDM would be enhanced by approximately three orders of magnitude in heavy atoms such as Fr. Laser-cooling and trapping techniques are expected to suppress statistical and systematic errors in precision measurements. The magneto-optical trap was achieved using stable rubidium in a developing factory of laser-cooled radioactive atoms. In light of the results from the rubidium experiments, we found that an upgrade of each apparatus is preferred for Fr trapping.

Kawamura Hirokazu

2014-03-01

24

Improved Measurement of the Electron EDM  

Science.gov (United States)

The electron is predicted to be slightly aspheric,ootnotetextI. B. Khriplovich, S. K. Lamoreaux, CP Violation Without Strangeness (Springer, New York, 1997). though no experiment has ever observed this deviation. Comparing the measured and predicted shape provides a powerful test of the standard model of particle physics. The shape is also intimately related to one of the largest outstanding questions in cosmology: why is the universe almost entirely devoid of antimatter? The electron's shape can be characterised by its electric dipole moment (EDM), de, which measures the deviation of its electric interactions from purely spherical. According to the standard model, this EDM is de 10-38 e.cm -- some eleven orders of magnitude below the current experimental limit. Most extensions to the standard model predict much larger values, potentially accessible to measurement.ootnotetextE. D. Commins, Electric dipole moments of leptons, in Advances in Atomic, Molecular, and Optical Physics, Vol. 40, B. Bederson and H.Walther (Eds.), Academic Press, New York, pp. 1-56 (1999). Hence, the search for the electron EDM is a search for physics beyond the standard model. Moreover, a non-zero breaks time-reversal symmetry which, in many models of particle physics, is equivalent to breaking the symmetry between matter and antimatter, known as CP symmetry. New CP-breaking physics is thought to be needed to explain the existence of a material universe.ootnotetextA. D. Sakharov, Violation of CP invariance, C asymmetry, and baryon asymmetry of the universe, Pis'ma ZhETF 5, 32 (1967). *Sov. Phys. JETP Lett. 5, 24 (1967).] We have used cold, polar molecules to measure the electron EDM, obtaining the result de= (-2.4 ±5.7stat±1.5syst) x10-28 e.cm. We set a new upper limit of with 90% confidence. Our result, consistent with zero, indicates that the electron is spherical at this improved level of precision. Our measurement, of atto-eV energy shifts in a molecule, probes new physics at the tera-eV energy scale. Many extensions to the standard model, such as the minimal supersymmetric standard model, naturally predict large EDMs and our measurement places significant constraints on the parameters of these theories.ootnotetextE. D. Commins and D. DeMille, ``The electric dipole moment of the electron,'' Chapter 14 in Lepton Dipole Moments Eds. B. L. Roberts and W. J. Marciano, (World Scientific, Singapore 2010).

Hinds, E. A.

2011-06-01

25

Advanced cold molecule electron EDM  

Science.gov (United States)

Measurement of a non-zero electric dipole moment (EDM) of the electron within a few orders of magnitude of the current best limit of |de| thorium monoxide (ThO) using a slow, cryogenic beam. We discuss the current status of the experiment. Based on a data set acquired from 14 hours of running time over a period of 2 days, we have achieved a 1-sigma statistical uncertainty of ?de = 1 × 10-28 e?cm/?T, where T is the running time in days.

Campbell, Wesley C.; Chan, Cheong; DeMille, David; Doyle, John M.; Gabrielse, Gerald; Gurevich, Yulia V.; Hess, Paul W.; Hutzler, Nicholas R.; Kirilov, Emil; O'Leary, Brendon; Petrik, Elizabeth S.; Spaun, Ben; Vutha, Amar C.

2013-08-01

26

Theoretical study of HfF$^+$ for the electron EDM search  

OpenAIRE

We report ab initio relativistic correlation calculations of potential curves and electric dipole transition moments for ten low-lying electronic states, effective electric field on the electron, hyperfine constants and radiative lifetimes for the $^3\\Delta_1$ state of cation of the heavy transition metal fluoride HfF$^+$, which it is suggested to be used in experiments to search for the electric dipole moment of the electron. It is obtained that HfF$^+$ has deeply bound $^1...

Petrov, A. N.; Mosyagin, N. S.; Titov, A. V.

2008-01-01

27

Towards the electron EDM search: Theoretical study of HfF+  

OpenAIRE

We report first ab initio relativistic correlation calculations of potential curves for ten low-lying electronic states, effective electric field on the electron and hyperfine constants for the ^3\\Delta_1 state of cation of a heavy transition metal fluoride, HfF^+, that is suggested to be used as the working state in experiments to search for the electric dipole moment of the electron. It is shown that HfF^+ has deeply bound ^1\\Sigma^+ ground state, its dissociation energy i...

Petrov, A. N.; Mosyagin, N. S.; Isaev, T. A.; Titov, A. V.

2006-01-01

28

Towards the electron EDM search. Theoretical study of PbF  

OpenAIRE

We report ab initio relativistic correlation calculations of potential curves and spectroscopic constants for four lowest-lying electronic states of the lead monofluoride. We also calculated parameters of the spin-rotational Hamiltonian for the ground and the first excited states including P,T-odd and P-odd terms. In particular, we have obtained hyperfine constants of the $^{207}$Pb nucleus. For the $^2\\Pi_{1/2}$ state $A_\\perp=-6859.6$ MHz, $A_\\|=9726.9$ MHz and for the A$^...

Baklanov, K. I.; Petrov, A. N.; Titov, A. V.; Kozlov, M. G.

2010-01-01

29

Zeeman interaction in ThO $H^3\\Delta_1$ for the electron EDM search  

CERN Document Server

The current limit on the electron's electric dipole moment, $|d_\\mathrm{e}|<8.7\\times 10^{-29} e {\\cdotp} {\\rm cm}$ (90% confidence), was set using the molecule thorium monoxide (ThO) in the $J=1$ rotational level of its $H ^3\\Delta_1$ electronic state [Science $\\bf 343$, 269 (2014)]. This state in ThO is very robust against systematic errors related to magnetic fields or geometric phases, due in part to its $\\Omega$-doublet structure. These systematics can be further suppressed by operating the experiment under conditions where the $g$-factor difference between the $\\Omega$-doublets is minimized. We consider the $g$-factors of the ThO $H^3\\Delta_1$ state both experimentally and theoretically, including dependence on $\\Omega$-doublets, rotational level, and external electric field. The calculated and measured values are in good agreement. We find that the $g$-factor difference between $\\Omega$-doublets is smaller in $J=2$ than in $J=1$, and reaches zero at an experimentally accessible electric field. This ...

Petrov, A N; Titov, A V; Hutzler, N R; Hess, P W; O'Leary, B R; Spaun, B; DeMille, D; Gabrielse, G; Doyle, J M

2014-01-01

30

Search for a permanent EDM using laser cooled radioactive atom  

International Nuclear Information System (INIS)

An Electric Dipole Moment (EDM) of the elementary particle is a good prove to observe the phenomena beyond the Standard Model. A non-zero EDM shows the violation of the time reversal symmetry, and under the CPT invariance it means the CP violation. In paramagnetic atoms, an electron EDM results in an atomic EDM enhanced by the factor of the 3rd power of the charge of the nucleus due the relativistic effects. A heaviest alkali element francium (Fr), which is the radioactive atom, has the largest enhancement factor K ? 895. Then, we are developing a high intensity laser cooled Fr factory at Cyclotron and Radioisotope Center (CYRIC), Tohoku University to perform the search for the EDM of Fr with the accuracy of 10-29 e · cm. The important points to overcome the current accuracy limit of the EDM are to realize the high intensity Fr source and to reduce the systematic error due to the motional magnetic field and inhomogeneous applied field. To reduce the dominant component of the systematic errors mentioned above, we will confine the Fr atoms in the small region with the Magneto-Optical Trap and optical lattice using the laser cooling and trapping techniques. The construction of the experimental apparatus is making progress, and the new thermal ionizer already produces the Fr of ?106 ions/s with the primary beam intensity 200 nA. The developments of the laser system and optical equipments are in progress, and the present status and future plan ofthe present status and future plan of the experimental project is reported.

31

Search for a permanent EDM using laser cooled radioactive atom  

Science.gov (United States)

An Electric Dipole Moment (EDM) of the elementary particle is a good prove to observe the phenomena beyond the Standard Model. A non-zero EDM shows the violation of the time reversal symmetry, and under the CPT invariance it means the CP violation. In paramagnetic atoms, an electron EDM results in an atomic EDM enhanced by the factor of the 3rd power of the charge of the nucleus due the relativistic effects. A heaviest alkali element francium (Fr), which is the radioactive atom, has the largest enhancement factor K ~ 895. Then, we are developing a high intensity laser cooled Fr factory at Cyclotron and Radioisotope Center (CYRIC), Tohoku University to perform the search for the EDM of Fr with the accuracy of 10-29 e · cm. The important points to overcome the current accuracy limit of the EDM are to realize the high intensity Fr source and to reduce the systematic error due to the motional magnetic field and inhomogeneous applied field. To reduce the dominant component of the systematic errors mentioned above, we will confine the Fr atoms in the small region with the Magneto-Optical Trap and optical lattice using the laser cooling and trapping techniques. The construction of the experimental apparatus is making progress, and the new thermal ionizer already produces the Fr of ~106 ions/s with the primary beam intensity 200 nA. The developments of the laser system and optical equipments are in progress, and the present status and future plan of the experimental project is reported.

Sakemi, Y.; Harada, K.; Hayamizu, T.; Itoh, M.; Kawamura, H.; Liu, S.; Nataraj, H. S.; Oikawa, A.; Saito, M.; Sato, T.; Yoshida, H. P.; Aoki, T.; Hatakeyama, A.; Murakami, T.; Imai, K.; Hatanaka, K.; Wakasa, T.; Shimizu, Y.; Uchida, M.

2011-07-01

32

Light ion EDM search in magnetic storage rings  

International Nuclear Information System (INIS)

Permanent electric dipole moments (EDMs) violate parity and time-reversal symmetry. Within the Standard Model (SM), they require CP violation and are many orders of magnitude below present experimental sensitivity. Many extensions of the SM predict much larger EDMs, which are therefore an excellent probe for the existence of 'new physics.' So far only electrically neutral systems were used for sensitive searches of EDMs. Several techniques, based on storing fast particles in a magnetic storage ring, are being developed to probe charged particles for an EDM. With the introduction of these novel experimental methods, high sensitivity for charged systems, in particular light nuclei, is within reach.

33

Search for neutron EDM using crystal techniques  

International Nuclear Information System (INIS)

Antisymmetric imaginary spin dependent scattering amplitudes related to atomic effects such as spin-orbit coupling, or nuclear effects such as parity violating weak forces or neutron EDM, generate particular spin rotations in perfect crystals. These effects are usually too small to be detected by normal neutron polarimetry. A new perfect crystal technique using Zeeman splitting as a polariser and termed Dual-Polarised-Beam polarimeter (DPB) with enhanced sensitivity, has been built and tested. The sensitivity of DPB to detect small spin rotations is about two orders of magnitudes better than classical polarisation techniques and it is only sensitive to antisymmetric effects. An extra gain arises from a specific enhancement effect close to the Bragg-edge directions. We have used this DPB technique in connection with a double crystal set-up to show that indeed effective electric fields up to 109 V/cm are accessible in suitable crystals by measuring the spin-orbit effect arising from this field. The conditions for EDM search are discussed. (author)

34

Light Ion EDM Search with a Magnetic Storage Ring  

International Nuclear Information System (INIS)

Permanent electric dipole moments (EDMs) violate parity and time-reversal symmetry, and are therefore practically zero in the Standard Model (SM). Many extensions of the SM predict much larger EDMs, which are therefore an excellent probe for the existence of new physics. Until recently it was believed that only electrically neutral systems could be used for a sensitive search for EDMs. The search on charged systems has become feasible with the introduction of a novel experimental method. This method makes use of the strong motional electric fields that a moving charged particle experiences in a magnetic field. It provides direct access to the very interesting realm of light nuclei and other charged particles, which so far has not been examined for EDMs. The features of this method and its possibilities are discussed

35

EDM searches at storage rings with Wien filters  

Energy Technology Data Exchange (ETDEWEB)

Future searches of an EDM of protons and deuterons at COSY storage ring in Juelich, envision the use of Wien filter acting as spin rotator. Crucial idea is that Wien filter produces spin kicks which give a growth of the EDM signal. In all approaches one starts with the injection of the vertically polarized beam. Radiofrequency Wien filter modulates spin tune of stored particles. If EDM is non-zero this modulation conspires with the EDM-induced rotation of the spin in the motional electric field in the ring and generates the EDM signal - the in-plane horizontal polarization. We discuss the duality between RF spin flipper and RF Wien filter and we argue why spin coherence time is equal for two devices. Another case is static Wien filter with constant fields. Behavior of spin vector is the same, but the machine is operated exactly at imperfection resonance (for protons, G?=2), which drastically decreases spin coherence time. Last case is more promising but it needs supercompensated magnetic lattice, an option which has to be studied further.

Saleev, Artem [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Kernphysik; Nikolaev, Kolya [Landau Institute, Chernogolovka (Russian Federation); Collaboration: JEDI-Collaboration

2013-07-01

36

EDM searches at storage rings with Wien filters  

International Nuclear Information System (INIS)

Future searches of an EDM of protons and deuterons at COSY storage ring in Juelich, envision the use of Wien filter acting as spin rotator. Crucial idea is that Wien filter produces spin kicks which give a growth of the EDM signal. In all approaches one starts with the injection of the vertically polarized beam. Radiofrequency Wien filter modulates spin tune of stored particles. If EDM is non-zero this modulation conspires with the EDM-induced rotation of the spin in the motional electric field in the ring and generates the EDM signal - the in-plane horizontal polarization. We discuss the duality between RF spin flipper and RF Wien filter and we argue why spin coherence time is equal for two devices. Another case is static Wien filter with constant fields. Behavior of spin vector is the same, but the machine is operated exactly at imperfection resonance (for protons, G?=2), which drastically decreases spin coherence time. Last case is more promising but it needs supercompensated magnetic lattice, an option which has to be studied further.

37

Recent Results from the PbO* Electron EDM Experiment  

Science.gov (United States)

Observation of an electric dipole moment (EDM) of the electron would imply new physics with CP violation beyond the Standard Model. A new generation of experiments propose to take advantage of the enhanced sensitivity of polar molecules to an electron EDM due to their enormous effective internal electric fields (>10 GV/cm). In addition, molecular states which exhibit parity doubling can be used to effectively reverse the direction of the internal electric field without changing external fields applied to the molecules. This novel experimental control leads to an enormous suppression of the systematic effects most common to EDM experiments. Our experiment uses a high temperature vapor cell containing PbO. The large vapor density leads to a higher counting rate than traditional beam experiments. Recent improvements to the experimental apparatus and new analysis techniques have now increased our optimal statistical sensitivity to better than 10-27 e.cm/day, potentially allowing for an improved limit on the electron EDM in a few days integration time. e will discuss these improvements as well as preliminary results and investigations of systematic effects.

Hamilton, Paul; Eckel, Stephen; Kirilov, Emil; Smith, Hunter; Demille, David

2011-06-01

38

Magnetic Field Stabilization for 129Xe EDM Search Experiment  

International Nuclear Information System (INIS)

Magnetic field stabilization is a crucial condition parameter for many kinds of ultra-high precision measurements such as a search for an electric dipole moment (EDM). The instability of magnetic field strength often arises from the drift of current flow in a solenoid coil to generate the magnetic field. For our EDM search experiment with maser oscillating diamagnetic 129Xe atoms, we have developed a new stabilized current source based on a feedback system which is devised to correct the amount of current flow measured precisely with high-precision digital multimeter and standard resistor. Using this new current source, we have successfully reduced the drifts of coil current by at least a factor of 100 compared to commercially available current sources.

39

Magnetic Field Stabilization for 129Xe EDM Search Experiment  

Science.gov (United States)

Magnetic field stabilization is a crucial condition parameter for many kinds of ultra-high precision measurements such as a search for an electric dipole moment (EDM). The instability of magnetic field strength often arises from the drift of current flow in a solenoid coil to generate the magnetic field. For our EDM search experiment with maser oscillating diamagnetic 129Xe atoms, we have developed a new stabilized current source based on a feedback system which is devised to correct the amount of current flow measured precisely with high-precision digital multimeter and standard resistor. Using this new current source, we have successfully reduced the drifts of coil current by at least a factor of 100 compared to commercially available current sources.

Furukawa, Takeshi; Inoue, Takeshi; Nanao, Tsubasa; Yoshimi, Akihiro; Tsuchiya, Masato; Hayashi, Hironori; Uchida, Makoto; Asahi, Koichiro

2011-09-01

40

High precision polarimetry for an EDM search on the deuteron  

International Nuclear Information System (INIS)

A new technique based an a magnetic storage ring is being developped to search for an EDM on charged particles such as the deuteron and proton. An increase in the vertical polarization signals a non-zero EDM. Optimal sensitivity is obtained by continuously monitoring the beam polarization with high statistical and systematic precision. A deuteron polarimeter concept based on slow extraction onto an aperture-limiting thick-walled carbon tube target was tested at COSY-Juelich and showed very high efficiency. Various systematic error sources were explored as well. In-depth systematic error studies were performed at KVI-Groningen, where also the necessary cross section and analyzing power data were previously measured.

41

EDM 1.0: electron direct methods.  

Science.gov (United States)

A computer program designed to provide a number of quantitative analysis tools for high-resolution imaging and electron diffraction data is described. The program includes basic image manipulation, both real space and reciprocal space image processing, Wiener-filtering, symmetry averaging, methods for quantification of electron diffraction patterns and two-dimensional direct methods. The program consists of a number of sub-programs written in a combination of C++, C and Fortran. It can be downloaded either as GNU source code or as binaries and has been compiled and verified on a wide range of platforms, both Unix based and PC's. Elements of the design philosophy as well as future possible extensions are described. PMID:15639355

Kilaas, R; Marks, L D; Own, C S

2005-02-01

42

EDM 1.0: Electron direct methods  

International Nuclear Information System (INIS)

A computer program designed to provide a number of quantitative analysis tools for high-resolution imaging and electron diffraction data is described. The program includes basic image manipulation, both real space and reciprocal space image processing, Wiener-filtering, symmetry averaging, methods for quantification of electron diffraction patterns and two-dimensional direct methods. The program consists of a number of sub-programs written in a combination of C++, C and Fortran. It can be downloaded either as GNU source code or as binaries and has been compiled and verified on a wide range of platforms, both Unix based and PC's. Elements of the design philosophy as well as future possible extensions are described

43

Probing the electron EDM with cold molecules  

OpenAIRE

We present progress towards a new measurement of the electron electric dipole moment using a cold supersonic beam of YbF molecules. Data are currently being taken with a sensitivity of $10^{-27}\\textrm{e.cm}/\\sqrt{\\textrm{day}}$. We therefore expect to make an improvement over the Tl experiment of Commins' group, which currently gives the most precise result. We discuss the systematic and statistical errors and comment on the future prospect of making a measurement at the le...

Sauer, B. E.; Ashworth, H. T.; Hudson, J. J.; Tarbutt, M. R.; Hinds, E. A.

2006-01-01

44

Effect on the electron EDM due to abelian gauginos in SUSY extra U(1) models  

OpenAIRE

The electric dipole moment of an electron (EDME) is investigated in the supersymmetric extra U(1) models. Neutralino sector is generally extended in these models and then the neutralino contribution will be important for the analysis of the EDME. Kinetic term mixings of abelian gauginos are taken into account in our analysis. Numerical results for the extra U(1) models show that the EDME can be affected by the extra U(1) in a certain range of soft supersymmetry breaking para...

Suematsu, Daijiro

1997-01-01

45

The Electron EDM and EDMs in Two-Higgs-Doublet Models  

OpenAIRE

Electric dipole moments constitute highly sensitive probes for CP-violating effects beyond the Standard Model. The upper limits obtained in various precision experiments can therefore be used to strongly restrict new physics models. However, relating the experimental information to parameters of a specific model is complicated by the presence of various sources for EDMs as well as large theory uncertainties in some of the relevant matrix elements. In this article, we address...

Jung, Martin

2014-01-01

46

The electron and neutron EDM from supersymmetric see-saw thresholds  

International Nuclear Information System (INIS)

We consider the corrections that arise at one loop when integrating out heavy fields in supersymmetric models. We show that, in type-I see-saw models, complex AN- and BN-terms of the heavy right-handed neutrino give radiative contributions to the neutron EDM, as well as new dominant contributions to the electron EDM. Type-II and type-III see-saw also predict a pure gauge correction that makes complex the masses of the weak gauginos. All the see-saw models can predict observable EDM for the electron and for the neutron in a peculiar ratio.

47

Electron EDM as a Sensitive Probe of PeV Scale Physics  

OpenAIRE

We give a quantitative analysis of the electric dipole moments as a probe of high scale physics. We focus on the electric dipole moment of the electron since the limit on it is the most stringent. Further, theoretical computations of it are free of QCD uncertainties. The analysis presented here first explores the probe of high scales via electron EDM within MSSM where the contributions to the electric dipole moment (EDM) arise from the chargino and the neutralino exchanges i...

Ibrahim, Tarek; Itani, Ahmad; Nath, Pran

2014-01-01

48

A Large Electron EDM and Minimal Flavor Violation  

CERN Document Server

The latest data from the ACME Collaboration have put a stringent constraint on the electric dipole moment (EDM) d_e of the electron. Nevertheless, the standard model (SM) prediction for d_e is many orders of magnitude below the new result, making it a powerful probe for physics beyond the SM. We carry out a model-independent study of d_e in the SM with right handed neutrinos and its extension with neutrino seesaw mechanism under the framework of minimal flavor violation. We find that d_e crucially depends on whether neutrinos are Dirac or Majorana particles. In the Majorana case, d_e can reach its experimental bound and constrains the scale of minimal flavor violation to be above a few hundred GeV or more. We also explore the effects on d_e of extra CP-violating sources in the Yukawa couplings of the right-handed neutrinos. Such new sources can have important effects on d_e.

He, Xiao-Gang; Li, Siao-Fong; Tandean, Jusak

2014-01-01

49

Improving the Limit on the Electron EDM: Data Acquisition and Systematics Studies in the ACME Experiment  

Science.gov (United States)

The ACME collaboration has completed a measurement setting a new upper limit on the size of the electron's permanent electric dipole moment (EDM). The existence of the EDM is well motivated by theories extending the standard model of particle physics, with predicted sizes very close to the current experimental limit. The new limit was set by measuring spin precession within the metastable H state of the polar molecule thorium monoxide (ThO). A particular focus here is on the automated data acquisition system developed to search for a precession phase odd under internal and external reversal of the electric field. Automated switching of many different experimental controls allowed a rapid diagnosis of major systematics, including the dominant systematic caused by non-reversing electric fields and laser polarization gradients. Polarimetry measurements made it possible to quantify and minimize the polarization gradients in our state preparation and probe lasers. Three separate measurements were used to determine the electric field that did not reverse when we tried to switch the field direction. The new bound of | de| < 8.7 x 10--29 e·cm is over an order of magnitude smaller than previous limits, and strongly limits T-violating physics at TeV energy scales.

Hess, Paul William

50

Improving the Limit on the Electron EDM: Data Acquisition and Systematics Studies in the ACME Experiment  

OpenAIRE

The ACME collaboration has completed a measurement setting a new upper limit on the size of the electron's permanent electric dipole moment (EDM). The existence of the EDM is well motivated by theories extending the standard model of particle physics, with predicted sizes very close to the current experimental limit. The new limit was set by measuring spin precession within the metastable H state of the polar molecule thorium monoxide (ThO). A particular focus here is on the automated data ac...

Hess, Paul William

2014-01-01

51

EDM planning using ETEAPOT with a resurrected AGS Electron Analogue ring  

CERN Document Server

There has been much recent interest in directly measuring the electric dipole moments (EDM) of the proton and the electron. Such a measurement will require storing a polarized beam of "frozen spin" particles in an all-electric storage ring. Only one such relativistic electric accelerator has ever been built---the "Electron Analogue" ring at Brookhaven National Laboratory in 1954. By chance this electron ring, long since dismantled, would have been appropriate both for measuring the electron EDM and to serve as an inexpensive prototype for the arguably more promising, but ten times more expensive, proton EDM measurement. Today it is cheaper yet to "resurrect" the Electron Analogue ring by simulating its performance computationally. This is one purpose for the present paper. To set up these calculations has required a kind of "archeological physics" to reconstitute the detailed Electron Analogue lattice design. The new UAL/ETEAPOT code, described in detail in an accompanying paper, has been developed for modeli...

Talman, Richard M

2015-01-01

52

Spectroscopic approach for an electron EDM measurement using neutral cesium atoms  

Science.gov (United States)

Observation of a permanent electric dipole moment of the electron (eEDM) would imply CP violating effects not contained in the Standard Model. We describe the state preparation and spectroscopy that will be used to measure the eEDM. Cesium atoms are guided into a measurement chamber, where they are laser-cooled and trapped in a pair of parallel one-dimensional optical lattices. The lattices thread three specially coated glass electric field plates. The measurement chamber is surrounded by a four layer magnetic shield inside of which eight magnetic field coils control the bias and gradient magnetic fields. A series of microwave and low frequency magnetic field pulses transfer the atoms into a superposition state that is sensitive to the eEDM signal. A measurement of the eEDM using neutral cesium atoms can obtain an ultimate shot noise limit of 3x10-30 e-cm.

Zhu, Kunyan; Solmeyer, Neal; Weiss, David S.

2012-06-01

53

Challenges and opportunities in the search for electric dipole moment (EDM) in ^225Ra atom  

Science.gov (United States)

The observation of a permanent electric dipole moment (EDM) in a non-degenerate system would indicate violation of time reversal symmetry. ^225Ra atom is a particularly attractive candidate for this search since it has a nuclear spin I=1/2 and has a significant nuclear octupole deformation. This property increases the Schiff moment of the nucleus and therefore enhances the atomic EDM. The half life (t1/2 =14.9 days) of ^225Ra is sufficiently long to perform EDM searches. Our group has already demonstrated the trapping of laser cooled Ra atoms in a magneto-optical trap (MOT) and transferring them to a far off resonant optical dipole trap (ODT). We will discuss our recent progress on manipulation of ultra cold Ra atoms in the ODT, efforts in improving our laser systems and generation of electric and magnetic fields required for the measurement.

Ranjan Kalita, Mukut; Bailey, Kevin; Dietrich, Matthew; Greene, John; Holt, Roy; Korsch, Wolfgang; Lu, Zheng-Tian; Mueller, Peter; O'Connor, Thomas; Parker, Richard; Sulai, Ibrahim; Singh, Jaideep

2011-10-01

54

Experimental search for the electron electric dipole moment with laser cooled francium atoms  

Science.gov (United States)

A laser cooled heavy atom is one of the candidates to search for the permanent electric dipole moment (EDM) of the electron due to the enhancement mechanism and its long coherence time. The laser cooled francium (Fr) factory has been constructed to perform the electron EDM search at the Cyclotron and Radioisotope Center, Tohoku University. The present status of Fr production and the EDM measurement system is presented.

Inoue, T.; 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.; Yoshida, H. P.; Yoshimi, A.; Sakemi, Y.

2014-12-01

55

Optical Spectroscopy of Tungsten Carbide Molecules for Permanent Electron Electric Dipole Moment Search  

Science.gov (United States)

Searching for a permanent electron electric dipole moment (EDM) is a powerful tool to probe for physics beyond the Standard Model. We identify the X^3?1 ground state of tungsten carbide molecules as a candidate system for the electron EDM search. We have developed a molecular beam source from pulse supersonic expansion technique and used laser induced fluorescence spectroscopy to detect the molecules through [20.6]?=2, v'=4 EDM experiment are revealed.

Lee, Jeongwon; Chen, Jinhai; Leanhardt, Aaron

2012-06-01

56

?-doubling and a limit for the enhancement of the electron EDM effect in diatomic molecules  

Science.gov (United States)

The recent experimental results for the upper limit for the electron EDM in heavy diatomic molecules with open electron shells YbF, ThO as well as proposals for the similar measurements in other heavy heteronuclear diatomic molecules are analyzed. It is argued that the enhancement factor for the electron EDM in a molecule, presented as an “effective” electric field Eeff is limited by the value Eeff,max?100?109 V/cm for the molecular states with any value of ? in diatomic molecules.

Chubukov, D. V.; Labzowsky, L. N.

2014-08-01

57

Mercury Monohalides: Suitability for Electron Electric Dipole Moment Searches  

OpenAIRE

Heavy polar diatomic molecules are the primary tools for searching for the T-violating permanent electric dipole moment of the electron (eEDM). Valence electrons in some molecules experience extremely large effective electric fields due to relativistic interactions. These large effective electric fields are crucial to the success of polar-molecule-based eEDM search experiments. Here we report on the results of relativistic ab initio calculations of the effective electric fie...

Prasannaa, V. S.; Vutha, A. C.; Abe, M.; Das, B. P.

2014-01-01

58

Preliminary Measurements for an Electron EDM Experiment in Thorium Monoxide  

Science.gov (United States)

The ACME collaboration aims to measure the eEDM via Ramsey spectroscopy of a cryogenic beam of ThO molecules in their metastable H state. This thesis describes the launch of this new experimental effort. A set of diode lasers has been built to address all the necessary ThO transitions. The laser frequencies were stabilized to a stable reference laser via a Fabry-Perot transfer cavity. A measurement of the magnetic dipole moment of the H state has been performed that is complementary to a previous measurement by the collaboration. This value is important for determining the sensitivity of the H state to magnetic fields, which can be a source of noise and systematic errors in the eEDM measurement. Experimental efforts to prepare the coherent superposition of the M=+/-1 Zeeman sublevels in the H, J=1 state that is the starting point of the eEDM experiment using transitions to the G state resulted in a better understanding of transitions between O-doublet states in an electric field. This led to a new technique for normalizing out shot-to-shot fluctuations in the molecular beam flux, which has also been demonstrated experimentally.

Gurevich, Yulia Vsevolodovna

59

Progress towards an electron EDM measurement using trapped hafnium fluoride ions  

Science.gov (United States)

Trapped molecular ions are an ideal platform for precision measurement of the electron electric dipole moment (eEDM). The low lying ^3?1 electronic state of HfF^+ is predicted to contribute a large sensitivity enhancement to an eEDM measurement. We create HfF^+ by optically exciting a supersonic beam of HfF with two photons to an autoionizing state. We then load the HfF^+ into a novel Paul trap optimized for fluorescence collection and field uniformity. We report on recent experiments in the trap, and on our general progress towards the eEDM measurement. This work is funded by the National Science Foundation and the Marsico Endowed Chair.

Grau, Matt; Loh, Huanqian; Cornell, Eric A.

2012-06-01

60

The electron and neutron EDM from supersymmetric see-saw thresholds  

OpenAIRE

We consider the corrections that arise at one loop when integrating out heavy fields in supersymmetric models. We show that, in type-I see-saw models, complex A and B terms of the heavy right-handed neutrino give radiative contributions to the neutron EDM, as well as new dominant contributions to the electron EDM. Type-II and type-III see-saw also predict a pure gauge correction that makes complex the masses of the weak gauginos. All the see-saw models can predict observable...

Giudice, Gian F.; Paradisi, Paride; Strumia, Alessandro

2010-01-01

61

Electron EDM as a Sensitive Probe of PeV Scale Physics  

CERN Document Server

We give a quantitative analysis of the electric dipole moments as a probe of high scale physics. We focus on the electric dipole moment of the electron since the limit on it is the most stringent. Further, theoretical computations of it are free of QCD uncertainties. The analysis presented here first explores the probe of high scales via electron EDM within MSSM where the contributions to the EDM arise from the chargino and the neutralino exchanges in loops. Here it is shown that the electron EDM can probe mass scales from tens of TeV into the PeV range.The analysis is then extended to include a vectorlike generation which can mix with the three ordinary generations. Here new CP phases arise and it is shown that the electron EDM now has not only a supersymmetric contribution from the exchange of charginos and neutralinos but also a non-supersymmetric contribution from the exchange of W and Z bosons. It is further shown that the interference of the supersymmetric and the non-supersymmetric contribution leads t...

Ibrahim, Tarek; Nath, Pran

2014-01-01

62

Bounds on R-parity violating parameters from the electron EDM  

International Nuclear Information System (INIS)

We study one-loop contributions to the fermion electric dipole moments in the minimal supersymmetric standard model with explicit R-parity violating interactions. Using the experimentally available limits on the electron EDM, we obtain new individual bounds on R-parity violating Yukawa couplings and put more stringent limits on certain parameters than those found previously. (author)

63

Neutron Diffraction and Optics of a Noncentrosymmetric Crystal. New Feasibility of a Search for Neutron EDM  

CERN Document Server

Recently strong electric fields (up to 10^9 V/cm) have been discovered, which affect the neutrons moving in noncentrosymmetric crystals. Such fields allow new polarization phenomena in neutron diffraction and optics and provide, for instance, a new feasibility of a search for the neutron electric dipole moment (EDM). A series of experiments was carried out in a few last years on study of the dynamical diffraction of polarized neutrons in thick (1-10 cm) quartz crystals, using the forward diffraction beam and Bragg angles close to 90^0. As well new neutron optics phenomena were investigated. The feasibility of experiment on a search for neutron EDM using Laue diffraction in crystals without a center of symmetry was tested at the reactors: WWR-M in Gatchina and HFR in Grenoble. It was shown that the sensitivity can reach (3 - 6)\\cdot 10^{-25}e cm per day for the available quartz crystal and cold neutron beam flux.

Fedorov, V V

2005-01-01

64

Lepton Flavour Violation and electron EDM in SUSY with a non-abelian flavour symmetry  

International Nuclear Information System (INIS)

We present the lepton sector phenomenology of a supersymmetric flavour model based on a SU(3) horizontal symmetry. This model successfully reproduces the observed fermion masses and mixings, without introducing unacceptably large SUSY sources of flavour and CP violation. We show that the model, which is at present weakly constrained, predicts the electron EDM and ??e,y to be within the final sensitivity of the currently running experiments, at least for SUSY masses within the reach of the LHC.

65

Broadband Velocity Modulation Spectroscopy of Molecular Ions for Use in the Jila Electron Edm Experiment  

Science.gov (United States)

The JILA electron electric dipole moment (eEDM) experiment will use a low-lying, metastable ^3?_1 state in trapped molecular ions of HfF^+ or ThF^+. Prior to this work, the low-lying states of these molecules had been investigated by PFI-ZEKE spectroscopy. However, there were no detailed studies of the electronic structure. The recently developed technique of frequency comb velocity modulation spectroscopy (VMS) provides broad-bandwidth, high-resolution, ion-sensitive spectroscopy, allowing the acquisition of 150 cm^{-1} of continuous spectra in 30 minutes over 1500 simultaneous channels. By supplementing this technique with cw-laser VMS, we have investigated the electronic structure of HfF^+ in the frequency range of 9950 to 14600 cm^{-1}, accurately fitting and assigning 16 rovibronic transitions involving 8 different electronic states including the X^1?^+ and a^3?_1 states. In addition, an observed ^3?_{0+} state with coupling to both the X and a states has been used in the actual eEDM experiment to coherently transfer population from the rovibronic ground state of HfF^+ to the eEDM science state. Furthermore, we report on current efforts of applying frequency comb VMS at 700 - 900 nm to the study of ThF^+, which has a lower energy ^3?_1 state and a greater effective electric field, and will provide increased sensitivity for a measurement of the eEDM. A. E. Leanhardt et. al., Journal of Molecular Spectroscopy 270, 1-25 (2011). B. J. Barker, I. O. Antonov, M. C. Heaven, K. A. Peterson, Journal of Chemical Physics 136, 104305 (2012). L. C. Sinclair, K. C. Cossel, T. Coffey, J. Ye, E. A. Cornell, Physical Review Letters 107, 093002 (2011). K.C. Cossel et. al., Chemical Physics Letters 546, 1-11 (2012).

Gresh, Daniel N.; Cossel, Kevin C.; Cornell, Eric A.; Ye, Jun

2013-06-01

66

A search engine for the engineering and equipment data management system (EDMS) at CERN  

International Nuclear Information System (INIS)

CERN, the European Laboratory for Particle Physics, located in Geneva -Switzerland, is currently building the LHC (Large Hadron Collider), a 27 km particle accelerator. The equipment life-cycle management of this project is provided by the Engineering and Equipment Data Management System (EDMS) Service. Using an Oracle database, it supports the management and follow-up of different kinds of documentation through the whole life cycle of the LHC project: design, manufacturing, installation, commissioning data etc... The equipment data collection phase is now slowing down and the project is getting closer to the 'As-Built' phase: the phase of the project consuming and exploring the large volumes of data stored since 1996. Searching through millions of items of information (documents, equipment parts, operations...) multiplied by dozens of points of view (operators, maintainers...) requires an efficient and flexible search engine. This paper describes the process followed by the team to implement the search engine for the LHC As-built project in the EDMS Service. The emphasis is put on the design decision to decouple the search engine from any user interface, potentially enabling other systems to also use it. Projections, algorithms, and the planned implementation are described in this paper. The implementation of the first version started in early 2007

67

About possibility to search the electron EDM at the level $10^{-28} \\div 10^{-30}$ e$\\cdot$cm and the constant of T-odd, P-odd scalar weak interaction of an electron with a nucleus at the level $10^{-5} \\div 10^{-7}$ in the heavy atoms and ferroelectrics  

OpenAIRE

The T-odd phenomenon of induction of the magnetic field by a static electric field provides to study the electron EDM and constants of T-odd, P-odd interaction of an electron with a nucleus. Measurement of this magnetic field for ferroelectric materials (like PbTiO_3) at the level B~3 10^{-18} G allows to derive the electric dipole moment of an electron at the level d_e ~ 10^{-30} e cm and the constant of T-odd scalar weak interaction of an electron with a nucleus at the lev...

Baryshevsky, V. G.

2005-01-01

68

Search for an EDM in diamagnetic atom 129Xe with nuclear spin maser technique  

Science.gov (United States)

Present status of the development of a nuclear spin maser for a 129Xe atomic EDM search is reported. We studied the frequency behavior of the spin maser presently under operation, and found that the drift in the frequency is correlated with the maser amplitude drift. Also, a high-voltage application system for the 129Xe precession cell was constructed. The leakage current measured is at present on the level of nA when a high voltage of 10 kV was applied, and is a subject of improvement to be achieved in near future.

Inoue, Takeshi; Tsuchiya, Masato; Hayashi, Hironori; Nanao, Tsubasa; Suzuki, Kunifumi; Yoshimi, Akihiro; Furukawa, Takeshi; Uchida, Makoto; Asahi, Koichiro

2011-09-01

69

Experimental search for 129Xe atomic EDM with nuclear spin maser technique  

Science.gov (United States)

The development of a nuclear spin oscillator system, namely a spin maser with an external feedback, for use in the search for 129Xe atomic EDM is presented. By introducing a new current source for the B0 field solenoid, drifts in the maser frequency were remarkably suppressed. This in turn clearly brought out the correlation between the maser frequency and the environmental field. Correcting for the effect of the environmental field, the frequency precision of 5 nHz in the measurement time of 45,000 s was attained. Origins of the remaining drifts in the maser frequency are now under investigation.

Inoue, T.; Furukawa, T.; Nanao, T.; Yoshimi, A.; Suzuki, K.; Chikamori, M.; Tsuchiya, M.; Hayashi, H.; Uchida, M.; Asahi, K.

70

Fermion EDMs with minimal flavor violation  

Science.gov (United States)

We study the electric dipole moments (EDMs) of fermions in the standard model supplemented with right-handed neutrinos and its extension including the neutrino seesaw mechanism under the framework of minimal flavor violation (MFV). In the quark sector, we find that the current experimental bound on the neutron EDM does not yield a significant restriction on the scale of MFV. In addition, we consider how MFV may affect the contribution of the strong theta-term to the neutron EDM. For the leptons, the existing EDM data also do not lead to strict limits if neutrinos are Dirac particles. On the other hand, if neutrinos are Majorana in nature, we find that the constraints become substantially stronger. Moreover, the results of the latest search for the electron EDM by the ACME Collaboration are sensitive to the MFV scale of order a few hundred GeV or higher. We also look at constraints from CP -violating electron-nucleon interactions that have been probed in atomic and molecular EDM searches.

He, Xiao-Gang; Lee, Chao-Jung; Li, Siao-Fong; Tandean, Jusak

2014-08-01

71

Fermion EDMs with Minimal Flavor Violation  

CERN Document Server

We study the electric dipole moments (EDMs) of fermions in the standard model supplemented with right-handed neutrinos and its extension including neutrino seesaw mechanism under the framework of minimal flavor violation (MFV). In the quark sector, we find that the current experimental bound on the neutron EDM does not yield a~significant restriction on the scale of MFV. In addition, we consider how MFV may affect the contribution of the strong theta-term to the neutron EDM. For the leptons, the existing EDM data also do not lead to strict limits if neutrinos are Dirac particles. On the other hand, if neutrinos are Majorana in nature, we find that the constraints become substantially stronger. Moreover, the results of the latest search for the electron EDM by the ACME Collaboration are sensitive to the MFV scale of order a~few hundred GeV or higher. We also look at constraints from $CP$-violating electron-nucleon interactions that may be probed in atomic or molecular EDM searches.

He, Xiao-Gang; Li, Siao-Fong; Tandean, Jusak

2014-01-01

72

Cosmological lower bound on the EDM of the electron  

International Nuclear Information System (INIS)

Multi-Higgs extensions of the standard model provide a natural mechanism for electroweak baryogenesis as well as a substantially big contribution to the dipole electric moments of the elementary particles. In the model with only two Higgs doublets both phenomena originate from one and the same source, namely CP violation in the neutral scalar sector. We present an estimate of the cosmological lower bound on the dipole moment of the electron, which appears to be numerically close to the experimental upper bound. (orig.)

73

Towards Improvements to the Statistical Sensitivity of the ACME Electron EDM Experiment  

Science.gov (United States)

Construction of the first generation ACME experiment [A. C. Vutha et al., J. Phys. B 43, 074007 (2010)] to measure the electron electric dipole moment (eEDM) has been completed, and data acquisition and analysis are currently underway. In order to further increase our statistical sensitivity, several improvements are being developed and implemented. We report on: progress towards increasing our total molecule flux with a new beam source; utilizing microwaves, optical pumping, and electrostatic beam focusing to increase the molecule flux in a single state; efficient state preparation via STIRAP; improving detection efficiency by photon cycling; and apparatus redesign to allow more efficient fluorescence collection.

Hutzler, Nicholas; Hess, Paul; Kirilov, Emil; O'Leary, Brendon; Petrik, Elizabeth; Spaun, Benjamin; Demille, David; Gabrielse, Gerald; Doyle, John

2012-06-01

74

A Healthy Electron/Neutron EDM in D3/D7 mu-Split-Like SUSY  

OpenAIRE

Within the framework of N=1 gauged supergravity, using a phenomenological model which can be obtained locally as a Swiss-Cheese Calabi-Yau string-theoretic compactification with a mobile D3-brane localized on a nearly sLag three-cycle in the Calabi-Yau and fluxed stacks of wrapped D7-branes, and which provides a natural realization of mu-Split SUSY, we show that in addition to getting a significant value of electron/neutron EDM d_{e,n}/e at two-loop level, one can obtain a s...

Dhuria, Mansi; Misra, Aalok

2013-01-01

75

Mercury Monohalides: Suitability for Electron Electric Dipole Moment Searches  

CERN Document Server

Heavy polar diatomic molecules are the primary tools for searching for the T-violating permanent electric dipole moment of the electron (eEDM). Valence electrons in some molecules experience extremely large effective electric fields due to relativistic interactions. These large effective electric fields are crucial to the success of polar-molecule-based eEDM search experiments. Here we report on the results of relativistic ab initio calculations of the effective electric fields in a series of molecules that are highly sensitive to an eEDM, the mercury monohalides (HgF, HgCl, HgBr,and HgI). We study the influence of the halide anions on effective electric field, and identify HgBr and HgI as interesting candidates for future electric dipole moment search experiments.

Prasannaa, V S; Abe, M; Das, B P

2014-01-01

76

The radon EDM apparatus  

Science.gov (United States)

The observation of a permanent electric dipole moment (EDM) at current experimentally accessible levels would provide clear evidence of physics beyond the Standard Model. EDMs violate CP symmetry, making them a possible route to explaining the size of the observed baryon asymmetry in the universe. The Radon EDM Experiment aims to search for an EDM in radon isotopes whose sensitivity to CP-odd interactions is enhanced by octupole-deformed nuclei. A prototype apparatus currently installed in the ISAC hall at TRIUMF includes a gas handling system to move radon from a collection foil to a measurement cell and auxiliary equipment for polarization diagnostics and validation. The features and capabilities of the apparatus are described and an overview of the experimental design for a gamma-ray-anisotropy based EDM measurement is provided.

Tardiff, E. R.; Rand, E. T.; Ball, G. C.; Chupp, T. E.; Garnsworthy, A. B.; Garrett, P.; Hayden, M. E.; Kierans, C. A.; Lorenzon, W.; Pearson, M. R.; Schaub, C.; Svensson, C. E.

2014-01-01

77

New results from the YbF EDM experiment  

Science.gov (United States)

The standard model of particle physics predicts that, due to time reversal symmetry, the permanent electric dipole moment (EDM) of the electron is very nearly zero. Many extensions to the standard model predict an electron EDM or other T-violating effects just below current experimental limits, thus there is great interest in new experiments and in improving current experimental precision. I will discuss our recent measurement of the electron EDM using YbF molecules. YbF is particularly sensitive to the electron EDM. This experiment uses a form of laser-radiofrequency double resonance spectroscopy to search for very small energy differences between hyperfine levels in a strong electric field. In addition to describing the experimental and analysis techniques, I will give an overview of the techniques we use to check for systematic errors. I will also describe planned improvements to the experiment which promise several orders of magnitude improvement in sensitivity.

Sauer, B. E.

2013-04-01

78

Electron EDM and soft leptogenesis in supersymmetric B-L extension of the Standard Model  

International Nuclear Information System (INIS)

We analyze the connection between electric dipole moment of the electron and the soft leptogenesis in supersymmetric B-L extension of the Standard Model. In this model, the B-L symmetry is radiatively broken at TeV scale. Therefore, it is a natural framework for low scale seesaw mechanism and also for implementing the soft leptogenesis. We show that the phases of trilinear soft SUSY breaking couplings A, which are relevant for the lepton asymmetry, are not constrained by the present experimental bounds on electric dipole moment. As in the MSSM extended with right-handed neutrinos, successful leptogenesis requires small bilinear coupling B, which is now given by AN and B-L breaking VEVs. SUSY B-L model with non-universal A-terms such that AN=0 while A??0 is a promising scenario for soft leptogenesis. The proposed EDM experiments will test this scenario in the future.

79

The phenomenon of time-reversal violating generation of static magnetic and electric fields is a basis of a new method for measurement of the electron EDM and T-odd P-odd constants of electron interaction with a nucleon beyond Standard Model  

OpenAIRE

It is shown that in the experiments for search of EDM of an electron (atom, molecule) the T-odd magnetic moment induced by an electric field and the T-odd electric dipole moment induced by a magnetic field will be also measured. It is discussed how to distinguish these contributions.

Baryshevsky, Vladimir

2004-01-01

80

Search for the electric dipole moment of the electron using metastable PbO  

International Nuclear Information System (INIS)

The metastable excited state a(1)[3?+] of PbO is proposed as a candidate system in which to search for an electron electric dipole moment (EDM). It is shown that the sensitivity to an electron EDM (de) could reach 10-31 e·cm--an improvement of >104 over the current limit. Observation of an electron EDM would provide definitive evidence for physics beyond the standard model, and many currently favored theories predict vertical bar de vertical bar>10-31. The sensitivity of the proposed technique arises from a combination of several unique properties of PbO, which simultaneously provide a large EDM enhancement factor, narrow magnetic resonance lines, and high counting rates. The structure of the nearly degenerate ?-doublet system in PbO permits the use of unique and powerful techniques for the rejection of systematic effects

81

Possible Search for the Electric Dipole Moment of the Electron in an Electrostatic Storage Ring  

Science.gov (United States)

A non-zero permanent electric dipole moment (EDM) of an electron would violate parity and time-reversal symmetries. Non-zero EDMs are predicted in the Standard Model, but are unobservably small. New physics incorporating new particles and new CP-violating phases can lead, through radiative corrections, to dramatic enhancements of the electron EDM, to within a few orders of magnitude of the current experimental limit, |de|electron EDM searches using molecular ions stored in a table-top electrostatic storage ring is described. Molecular ions with long-lived paramagnetic states such as WN^+ could be injected and stored in large numbers and with long coherence times. Sensitivities approaching a few x10-30 e cm/?day, appear possible, a potential improvement by three orders of magnitude.

Kawall, David

2011-11-01

82

A Healthy Electron/Neutron EDM in D3/D7 mu-Split SUSY  

CERN Document Server

Within the framework of N=1 gauged supergravity, using a phenomenological model which can be obtained locally as a Swiss-Cheese Calabi-Yau string-theoretic compactification with a mobile D3-brane localized on a nearly sLag three-cycle in the Calabi-Yau and fluxed stacks of wrapped D7-branes, and which provides a natural realization of mu-Split SUSY, we show that in addition to getting a significant value of electron/neutron EDM d_{e,n}/e at two-loop level, one can obtain a sizable contribution of d_{e,n}/e even at one-loop level. We obtain d_{e}/e ~ O(10^{-29}) cm from two-loop diagrams involving heavy sfermions and a light Higgs, and d_{e}/e ~ O(10^{-32}) cm from one-loop diagram involving heavy chargino and a light Higgs. Also, d_{n}/e ~ O(10^{-33}) cm from one-loop diagram involving SM-like quarks and Higgs. Next, by considering a Barr-Zee diagram involving W bosons and Higgs, and conjecturing that the CP-violating phase can appear from a linear combination of Higgs doublet obtained in the context of mu-sp...

Dhuria, Mansi

2013-01-01

83

On the neutron EDM search in the Laue diffraction by the crystal without a centre of symmetry  

International Nuclear Information System (INIS)

A new method of neutron electric dipole moment (EDM) searching is proposed. It is based on the spin dependence of the pendelous phase of a neutron diffracted by the noncentrosymmetric crystal. A two-crystal set up is proposed and analyzed to get the big enough luminosity. With the strong interplanar electric field of the crystal and the sufficiently long time of the neutron passage through the crystals for the Bragg angles close to ?/2 it makes possible to exceed the sensitivity achieved with the ultra cold neutron method. 15 refs.; 5 figs.; 1 tab

84

Extensive Frequency Comb Velocity Modulation Spectroscopy of ThF^+ for Use in the Jila Electron Edm Experiment  

Science.gov (United States)

The metastable ^3?_1 state in trapped HfF^+ is being used for an ongoing measurement of the electron electric dipole moment (eEDM) ThF^+, which has a larger effective electric field and a longer-lived ^3?_1 state, offers increased sensitivity for an eEDM measurement. Recently, the Heaven group has spectroscopically studied the low-lying states of ThF^+. However, to date there is no detailed information available about technically-accessible laser transitions in the near-infrared region of the spectrum, which are necessary for state preparation and detection in an eEDM experiment. By applying the technique of frequency comb velocity modulation spectroscopy (VMS) to ThF^+ we can acquire 150 cm-1 of continuous, ion-sensitive spectra with 150 MHz resolution in 25 minutes. Here, we report on extensive broadband, high-resolution survey spectroscopy of ThF^+ in the near-IR where we have observed and accurately fit several rovibronic transitions. In addition, we have observed and characterized numerous rovibronic transitions from an unknown thoriated species of molecular ions. H. Loh, K. C. Cossel, M. C. Grau, K.-K. Ni, E. R. Meyer, J. L. Bohn, J. Ye, E. A. Cornell, Science 342, 1220 (2013). B. J. Barker, I. O. Antonov, M. C. Heaven, K. A. Peterson, J. Chem. Phys. 136, 104305 (2012). L. C. Sinclair, K. C. Cossel, T. Coffey, J. Ye, E. A. Cornell, PRL 107, 093002 (2011).

Gresh, Dan; Cossel, Kevin; Ye, Jun; Cornell, Eric

2014-06-01

85

Establishment of ''Internal Rules'' and EDMS - Electronic Document Management System at NPP NEK  

International Nuclear Information System (INIS)

The main purpose of this paper is to present NPP's plans regarding the on-going project that started in November 2011, and that is related to the establishment of ''Internal Rules'' and EDMS - Electronic Document Management System.The term ''Internal Rules'' has been directly translated from Slovenian language (''Notranja pravila'') and adopted from the translated version of appropriate Slovenian national codes (ZVDAGA [1] in Slovenian language or PDAAIA [2] in English version). ''Internal Rules on capture and storage of materials in digital form'' refer to the rules adopted by a person as his/her internal act with reference to storage of his/her material. The main purpose for the establishment of the Internal Rules is to be able to justify that Krsko NPP is organized in compliance with the national codes covering that subject and strictly performing according to those Internal Rules. Once a Slovenian company achieves recognized and registered status in accordance with the Internal Rules document that has been certified and approved by the ARS (Archives of the Republic Slovenia), such company can utilize e-documents in the same way as they would utilize physical documents. Furthermore, a Slovenian company with approved Internal Rules can use e-documents in any legal aspect associated with the document's life cycle and the document's content as they would use the physical document or an authorized and approved copy of the physical document. Related to the nuclear regulatory background, NEK operates in compliance with the Slovenian legislation and also the US codes, regulations and guidelines; therefore, regarding the NPP specific documents, the Internal Rules and EDMS must also be in compliance with them. Since early 1990's, NEK has implemented document/records management system oriented towards supporting storage and management of physical documents/records and controlling distribution of active document copies. Document/records management system was supported by two applications (DCM-Document Control Module andQRM-Quality Records Management). Both computer applications were designed in order to fulfil requirements of the criteria VI (Document Control) and criteria XVII (Quality Assurance Records) of the US code [3]. In order to prevent confusion, clarifications regarding the terms ''documents'' and ''records'' are the following: Documents are an organized collection of information or objects that can be treated as a unit. A document may or may not meet the definition of a record. Records are sub-set of all information or all documents held by a person or organisation. Records present information, regardless of physical form or characteristics, appropriate for preservation as evidence of the organization, functions, policies, decisions, procedures, operations, or other activities of the organization. Examples of where this information may reside are books, papers, maps, photographs, machine-readable electronic files, or other documentary materials. Quality Assurance Records related to the NPPs are the records which furnish documentary evidence of the quality of items and activities affecting quality. For the purpose of the standards [4] and [5], a document is considered a quality assurance record when it has been completed.(author).

86

Atomic properties of Ra for a future EDM measurement  

Science.gov (United States)

Searches for non-zero permanent electric-dipole moments (EDM) of particles, atoms, and molecules represent remarkable opportunity to probe new physics beyond the standard model. The EDMs arise from the violations of both parity and time-reversal invariance. Atomic EDMs caused by the nuclear parity and time invariance violating effects are enhanced in certain diamagnetic atoms, such as ^199Hg and ^225Ra. For the latter, there is additional enhancement due to close states of opposite parity and the large nuclear charge Z [Dzuba et al., PRA 61, 062509 (2000)]. The search for EDM in ^225Ra is presently underway [Holt et al., Nucl. Phys. A 844, 53c (2010)]. Few atomic properties of Ra are experimentally known. In this work, we carry out a systematic study of Ra atomic properties of interest to the EDM search using recently developed relativistic ab initio method [Safronova at. al, PRA 80, 012516 (2009)] that allows to accurately treat correlation corrections in atoms with a few valence electrons. This method combines the coupled-cluster method, that yielded excellent results for monovalent systems, with the configuration-interaction approach. We have calculated energy levels, electric-dipole matrix elements, lifetimes, hyperfine constants, and polarizabilities.

Zuhrianda, Z.; Safronova, Marianna; Porsev, Sergey; Kozlov, Mikhail

2012-06-01

87

Muon and Deuteron EDM Experiments  

International Nuclear Information System (INIS)

Permanent electric dipole moments (EDMs) violate parity and time-reversal symmetry, and are therefore practically zero in the Standard Model (SM). Many extensions of the SM predict much larger EDMs, which are therefore an excellent probe for the existence of new physics. Until recently it was believed that only electrically neutral systems could be used for sensitive search of EDMs. The search on charged systems has become feasible with the introduction of a novel experimental method. This method makes use of the strong motional electric fields that a relativistic charged particle experiences in a magnetic field. It provides direct access to the very interesting realm of light nuclei and other charged particles, which so far have not been examined for EDMs. The features of this method and its possibilities are discussed

88

Optical Spectroscopy of Tungsten Carbide for Uncertainty Analysis in Electron Electric Dipole Moment Search  

OpenAIRE

We perform laser induced fluorescence(LIF) spectroscopy on a pulsed supersonic beam of tungsten carbide(WC) molecules, which has been proposed as a candidate molecular system for a permanent Electric Dipole Moment(EDM) search of the electron in its rovibrational ground state of the X3Delta1 state. In particular, [20.6]Omega=2, v'=4

Lee, J.; Chen, J.; Skripnikov, L. V.; Petrov, A. N.; Titov, A. V.; Mosyagin, N. S.; Leanhardt, A. E.

2012-01-01

89

Preliminary Measurements for an Electron EDM Experiment in ThO  

OpenAIRE

The ACME collaboration aims to measure the eEDM via Ramsey spectroscopy of a cryogenic beam of ThO molecules in their metastable H state. This thesis describes the launch of this new experimental effort. A set of diode lasers has been built to address all the necessary ThO transitions. The laser frequencies were stabilized to a stable reference laser via a \\(Fabry-P\\acute{e}rot\\) transfer cavity. A measurement of the magnetic dipole moment of the H state has been performed that is complementa...

Gurevich, Yulia

2011-01-01

90

Search for the electron's electric dipole moment with a cold molecular beam of ThO  

Science.gov (United States)

We describe a method for an improved search for the electric dipole moment (EDM) of the electron, using a cold molecular beam of thorium monoxide (ThO). We identify the metastable H state in ThO as being highly sensitive to the CP-violating EDM of the electron. ThO in a beam is shown to have excellent properties for rejection of systematic errors and for efficient state preparation and detection. We report on recent progress in the production of cold ThO molecules and measurement of the lifetime of the H state.

Vutha, Amar C.; Baker, O. Keith; Campbell, Wesley C.; Demille, David; Doyle, John M.; Gabrielse, Gerald; Gurevich, Yulia V.; Jansen, Maarten A. H. M.

2008-05-01

91

Proposal for a sensitive search for electric dipole moment of electron with matrix-isolated radicals  

OpenAIRE

We propose using matrix-isolated paramagnetic diatomic molecules to search for the electric dipole moment of electron (eEDM). As was suggested by Shapiro in 1968, the eEDM leads to a magnetization of a sample in the external electric field. In a typical condensed matter experiment, the effective field on the unpaired electron is of the same order of magnitude as the laboratory field, typically about $10^{5}$V/cm. We exploit the fact that the effective electric field inside h...

Kozlov, M. G.; Derevianko, Andrei

2006-01-01

92

Theoretical study of ThO for the electron electric dipole moment search  

OpenAIRE

An experiment to search for the electron electric dipole moment (\\eEDM) on the metastable $H^3\\Delta_1$ state of ThO molecule was proposed and now in the final stage of preparation by the ACME collaboration [http://www.electronedm.org]. To interpret the experiment in terms of \\eEDM\\ and dimensionless constant $k_{T,P}$ characterizing the strength of the scalar T,P-odd electron-nucleus neutral current interaction, an accurate theoretical study of effective electric field on e...

Skripnikov, L. V.; Petrov, A. N.; Titov, A. V.

2013-01-01

93

Towards high-precision polarimetry for an EDM search on the deuteron  

International Nuclear Information System (INIS)

A finite Electric Dipole Moment (EDM) in any fundamental system would constitute a signal for New Physics. The deuteron presents itself as an optimal candidate due to its high sensitivity for CP odd parts of nuclear forces, together with being easily polarizable and having a small anomalous magnetic moment. A new storage ring technique is being developed, for which a small change in the vertical polarization would be a signal of a non-zero EDM. A novel polarimeter concept is under investigation. Besides being highly efficient, this polarimeter allows for continuous monitoring of the beam polarization, guaranteeing optimal sensitivity. Detailed studies on systematic error control, in addition to the measurement of cross sections and analyzing powers, were carried out at KVI-Groningen. Efficiency measurements were conducted at COSY-Juelich yielding a high efficiency up to 1.5%. The (statistics limited) ability to track changes in polarization at the level of a few hundred parts-per-million has been demonstrated. Further studies and developments to meet the final goal of sub-part-per-million sensitivity are in progress.

94

Status of the University of Oklahoma Search for the Signature of an e-EDM in the Interaction of the PbF Molecule with an Electric Field  

Science.gov (United States)

This talk presents an update of an ongoing effort at the University of Oklahoma to measure the electric dipole moment of the electron (e-EDM) by studying the interaction of a molecular beam of ^208Pb^19F molecules with an external electric field.

Shafer-Ray, N. E.

2011-06-01

95

Optical spectroscopy of tungsten carbide for uncertainty analysis in electron electric-dipole-moment search  

Science.gov (United States)

We perform laser-induced fluorescence spectroscopy on a pulsed supersonic beam of tungsten carbide (WC) molecules, which has been proposed as a candidate molecular system for a permanent electric dipole moment (EDM) search of the electron in its rovibrational ground state of the X3?1 state. In particular, [20.6]?=2,v'=4?X3?1,v''=0 transition at 485 nm was used for the detection. The hyperfine structure and the ? doublet of the transition is measured, which are essential for estimating the size of the potential systematic uncertainties for electron EDM measurement. For further suppression of the systematic uncertainty, an alternative electron EDM measurement scheme utilizing the g factor crossing point of the ?-doublet levels is discussed. On the other hand, flux and internal temperature of the molecular beam are characterized, which sets the limit on the statistical uncertainty of the electron EDM experiment. With the given results, the prospect of electron EDM experiment with the X3?1 state of WC molecule is discussed.

Lee, J.; Chen, J.; Skripnikov, L. V.; Petrov, A. N.; Titov, A. V.; Mosyagin, N. S.; Leanhardt, A. E.

2013-02-01

96

Optical Spectroscopy of Tungsten Carbide for Uncertainty Analysis in Electron Electric Dipole Moment Search  

CERN Document Server

We perform laser induced fluorescence(LIF) spectroscopy on a pulsed supersonic beam of tungsten carbide(WC) molecules, which has been proposed as a candidate molecular system for a permanent Electric Dipole Moment(EDM) search of the electron in its rovibrational ground state of the X3Delta1 state. In particular, [20.6]Omega=2, v'=4 <- X3Delta1,v"=0 transition at 485nm was used for the detection. The hyperfine structure and the Omega-doublet of the transition are measured, which are essential for estimating the size of the potential systematic uncertainties for electron EDM measurement. For further suppression of the systematic uncertainty, an alternative electron EDM measurement scheme utilizing the g factor crossing point of the Omega-doublet levels is discussed. On the other hand, flux and internal temperature of the molecular beam are characterized, which sets the limit on the statistical uncertainty of the electron EDM experiment. With the given results, the prospect of electron EDM experiment with the...

Lee, J; Skripnikov, L V; Petrov, A N; Titov, A V; Mosyagin, N S; Leanhardt, A E

2012-01-01

97

Experimental search for the electron Electric Dipole Moment using solid state techniques  

International Nuclear Information System (INIS)

We report results of an experimental search for the permanent Electric Dipole Moment (EDM) of the electron using a solid state system. The experiment uses a paramagnetic insulator (gadolinium gallium garnet) with a large magnetic response at low temperatures. The presence of the electron EDM leads to a finite magnetization when the garnet sample is subjected to a strong electric field. The resulting magnetization can be measured using a superconducting quantum interference device (SQUID) as a magnetometer. With considerable efforts made towards controlling various sources of systematic effects, the experiment is currently free of spurious signals larger than the SQUID noise. We report the value of electron EDM of (-5.57 ± 7.98 ± 0.12) x 10-25e-cm with 120 hours of data.

98

Experimental search for the electron Electric Dipole Moment using solid state techniques  

Science.gov (United States)

We report results of an experimental search for the permanent Electric Dipole Moment (EDM) of the electron using a solid state system. The experiment uses a paramagnetic insulator (gadolinium gallium garnet) with a large magnetic response at low temperatures. The presence of the electron EDM leads to a finite magnetization when the garnet sample is subjected to a strong electric field. The resulting magnetization can be measured using a superconducting quantum interference device (SQUID) as a magnetometer. With considerable efforts made towards controlling various sources of systematic effects, the experiment is currently free of spurious signals larger than the SQUID noise. We report the value of electron EDM of (-5.57 ± 7.98 ± 0.12) × 10-25e-cm with 120 hours of data.

Kim, Y. J.; Liu, C.-Y.; Lamoreaux, S. K.; Reddy, G.

2011-09-01

99

A Perturbative Analysis of Electron EDM and CP Violation in Two Higgs Doublet Models  

CERN Document Server

I consider a general two Higgs doublet model with CP violation. I give a perturbative expansion for the mass eigenstates in terms of the small CP violating phase. I use these analytical expressions to show that $\\mathcal{O}(10^{-1})$ CP violation is allowed by the experimental bounds on the electron electric dipole momnent in some regions of the parameter space. These regions also include parameters that are expected to give a strongly first order electroweak phase transition required for electroweak baryogenesis. I also comment on how to incorporate the CP violation into the searches for a strongly first order electroweak phase transition which could explain the matter/anti-matter asymmetry in the universe.

Ipek, Seyda

2013-01-01

100

Electric dipole moments (EDM) of ionic atoms  

International Nuclear Information System (INIS)

Recent investigations show that the second-order perturbation calculations of electric dipole moments (EDM) from the finite nuclear size as well as the relativistic effects are all canceled out by the third-order perturbation effects and that this is due to electron screening. To derive the nucleon EDM from the nucleus, we propose to measure the EDM of an ionic system. In this case, it is shown that the nucleon EDM can survive by the reduction factor of 1/Z for the ionic system with one electron stripped off.

101

Electric dipole moments (EDM) of ionic atoms  

Science.gov (United States)

Recent investigations show that the second-order perturbation calculations of electric dipole moments (EDM) from the finite nuclear size as well as the relativistic effects are all canceled out by the third-order perturbation effects and that this is due to electron screening. To derive the nucleon EDM from the nucleus, we propose to measure the EDM of an ionic system. In this case, it is shown that the nucleon EDM can survive by the reduction factor of 1/Z for the ionic system with one electron stripped off.

Oshima, Sachiko

2010-03-01

102

Search for the electron electric dipole moment using ?-doublet levels in PbO  

Science.gov (United States)

We present results of an experiment to probe for the electric dipole moment (EDM) of the electron using an ?-doublet state in a polar molecule. If the molecule is both massive and has a large molecular-fixed frame dipole moment, then the ?-doublet states have the potential to greatly increase the sensitivity of experiments searching for the EDM while also allowing for new methods of systematic error rejection. Here, we use the metastable a(1)3?+ state of lead monoxide (PbO) to probe for the electron EDM. Our best fit for the electron EDM of de=(-4.4±9.5stat±1.8syst)×10-27ecm allows us to place an upper limit on the magnitude of the EDM of |de|<1.7×10-26ecm (90% confidence). While this is less stringent than limits from other, previous experiments, our work emphasizes the systematic error rejection properties associated with the ?-doublet level structure. The results should inform the work of other, ongoing experiments that use molecules with analogous level structure.

Eckel, S.; Hamilton, P.; Kirilov, E.; Smith, H. W.; DeMille, D.

2013-05-01

103

Search for the electron electric dipole moment using $\\Omega$-doublet levels in PbO$^*$  

CERN Document Server

We present results of the first experiment to probe for the electric dipole moment (EDM) of the electron using an $\\Omega$-doublet state in a polar molecule. If the molecule is both massive and has a large molecular-fixed frame dipole moment, then the $\\Omega$-doublet states have the potential to greatly increase the sensitivity of experiments searching for the EDM while also allowing for new methods of systematic error rejection. Here, we use the metastable $a(1)^3\\Sigma^+$ state of lead monoxide (PbO) to probe for the electron EDM. Our best fit for the electron EDM of $d_e = (-4.4\\pm9.5_\\text{stat}\\pm1.8_\\text{syst})\\times10^{-27}\\ecm$ allows us to place an upper limit on the magnitude of the EDM of $|d_e|<1.7\\times10^{-26}\\ecm$ (90% confidence). While this is less stringent than limits from other, previous experiments, our work emphasizes the systematic error rejection properties associated with the $\\Omega$-doublet level structure. The results should inform the work of other, ongoing experiments that u...

Eckel, S; Kirilov, E; Smith, H W; DeMille, D

2013-01-01

104

Search for the electron electric dipole moment using $\\Omega$-doublet levels in PbO$^*$  

OpenAIRE

We present results of the first experiment to probe for the electric dipole moment (EDM) of the electron using an $\\Omega$-doublet state in a polar molecule. If the molecule is both massive and has a large molecular-fixed frame dipole moment, then the $\\Omega$-doublet states have the potential to greatly increase the sensitivity of experiments searching for the EDM while also allowing for new methods of systematic error rejection. Here, we use the metastable $a(1)^3\\Sigma^+$...

Eckel, S.; Hamilton, P.; Kirilov, E.; Smith, H. W.; Demille, D.

2013-01-01

105

Gauge invariant Barr-Zee type contributions to fermionic EDMs in the two-Higgs doublet models  

CERN Document Server

We calculate all gauge invariant Barr-Zee type contributions to fermionic electric dipole moments (EDMs) in the two-Higgs doublet models (2HDM) with softly broken Z2 symmetry. We start by studying the tensor structure of h to VV' part in the Barr-Zee diagrams, and we calculate the effective couplings in gauge invariant way using the pinch technique. Then we calculate all Barr-Zee diagrams relevant for electron and neutron EDMs. We make bounds on the parameter space in type-I, type-II, type-X, and type-Y 2HDMs. The electron and neutron EDMs are complementary to each other in discrimination of the 2HDMs. Type-II and type-X 2HDMs are strongly constrained by recent ACME experiment's result, and future experiments of electron and neutron EDMs may search O(10) TeV physics.

Abe, Tomohiro; Kitahara, Teppei; Tobioka, Kohsaku

2014-01-01

106

Enhancement factor for the electron electric dipole moment in francium and gold atoms  

OpenAIRE

If electrons had an electric dipole moment (EDM) they would induce EDMs of atoms. The ratio of the atomic EDM to the electron EDM for a particular atom is called the enhancement factor, R. We calculate the enhancement factor for the francium and gold atoms, with the results 910 plus/minus 5% for Fr and 260 plus/minus 15% for Au. The large values of these enhancement factors make these atoms attractive for electron EDM measurements, and hence the search for time-reversal inva...

Byrnes, T. M. R.; Dzuba, V. A.; Flambaum, V. V.; Murray, D. W.

1998-01-01

107

Solid State Systems for Electron Electric Dipole Moment and other Fundamental Measurements  

OpenAIRE

In 1968, F.L. Shapiro published the suggestion that one could search for an electron EDM by applying a strong electric field to a substance that has an unpaired electron spin; at low temperature, the EDM interaction would lead to a net sample magnetization that can be detected with a SQUID magnetometer. One experimental EDM search based on this technique was published, and for a number of reasons including high sample conductivity, high operating temperature, and limited SQU...

Lamoreaux, S. K.

2001-01-01

108

Search for the neutron EDM by crystal-diffraction method. Test experiment and future progress  

Science.gov (United States)

Possible future progress of the crystal-diffraction neutron electric dipole moment search experiment is discussed. A storage modification of the experiment is proposed. It is demonstrated that sensitivity of the method can be a few 10 -27 e cm for the BSO crystal with the size 10×10×10 cm 3 and expected luminosity of European Spallation Source (ESS).

Fedorov, V. V.; Voronin, V. V.; Braginetz, Yu. P.

2011-06-01

109

Standard model extensions for PV electron scattering, g-2, EDM: Overview  

CERN Document Server

I review how various extensions of the Standard Model, in particular supersymmetry and extra neutral gauge bosons, may affect low energy observables, including parity-violating electron scattering and related observables, as well as electric and magnetic dipole moments.

Erler, Jens

2011-01-01

110

The electron and neutron EDM in the 3-3-1 model with heavy leptons  

OpenAIRE

We calculate the electric dipole moment for the electron and neutron in the framework of the 3-3-1 model with heavy charged leptons. We assume that the only source of CP violation arise from a complex trilinear coupling constant and the three VEVs complex. Only one physical phase survives.

Conto, G.; Pleitez, V.

2014-01-01

111

Slepton Flavor Nonuniversality, the Muon EDM and its Proposed sensitive Search at Brookhaven  

OpenAIRE

We analyze the electric dipole moment of the electron ($d_e$), of the neutron ($d_n$) and of the muon ($d_{\\mu}$) using the cancellation mechanism in the presence of nonuniversalities of the soft breaking parameters. It is shown that the nonuniversalities in the slepton sector produce a strong violation of the scaling relation $d_{\\mu}/d_e\\simeq m_{\\mu}/m_e$ in the cancellation region. An analysis of $d_e, d_n$ and $d_{\\mu}$ under the constraints of the current experimental ...

Ibrahim, Tarek; Nath, Pran

2001-01-01

112

Electron EDM and soft leptogenesis in supersymmetric B-L extension of the standard model  

OpenAIRE

We analyze the connection between electric dipole moment of the electron and the soft leptogenesis in supersymmetric $B-L$ extension of the standard model. In this model, the $B-L$ symmetry is radiatively broken at TeV scale. Therefore, it is a natural framework for low scale seesaw mechanism and also for implementing the soft leptogenesis. We show that the phases of trilinear soft SUSY breaking couplings $A$, which are relevant for the lepton asymmetry, are not constrained ...

Kajiyama, Yuji; Khalil, Shaaban; Raidal, Martti

2009-01-01

113

Perturbative Analysis of the Electron EDM and CP Violation in Two Higgs Doublet Models  

OpenAIRE

I consider a general two Higgs doublet model with CP violation. I give a perturbative expansion for the mass eigenstates in terms of the small CP violating phase. I use these analytical expressions to show that $\\mathcal{O}(10^{-2})$ CP violation is allowed by the experimental bounds on the electron electric dipole momnent in some regions of the parameter space. These regions also include parameters that are expected to give a strongly first order electroweak phase transitio...

Ipek, Seyda

2013-01-01

114

Low Scale Seesaw, Electron EDM and Leptogenesis in a Model with Spontaneous CP Violation  

OpenAIRE

Strong correlations between leptogenesis and low energy CP violating leptonic processes have been shown by us to exist in the minimal left-right symmetric model with spontaneous CP violation. In this note, we investigate the implications of this model for the electric dipole moment of the electron. With an additional broken U(1)_H symmetry, the seesaw scale can be lowered to close to the electroweak scale. This additional symmetry also makes the connection between CP violati...

Chen, Mu-chun; Mahanthappa, K. T.

2006-01-01

115

Electron EDM and soft leptogenesis in supersymmetric B-L extension of the standard model  

CERN Document Server

We analyze the connection between electric dipole moment of the electron and the soft leptogenesis in supersymmetric $B-L$ extension of the standard model. In this model, the $B-L$ symmetry is radiatively broken at TeV scale. Therefore, it is a natural framework for low scale seesaw mechanism and also for implementing the soft leptogenesis. We show that the phases of trilinear soft SUSY breaking couplings $A$, which are relevant for the lepton asymmetry, are not constrained by the present experimental bounds on electric dipole moment. As in the MSSM extended with right-handed neutrinos, successful leptogenesis requires small bilinear coupling $B$, which is now given by $A_N$ and $B-L$ breaking VEVs. SUSY $B-L$ model with non-universal $A$-terms such that $A_N=0$ while $A_{\

Kajiyama, Yuji; Raidal, Martti

2009-01-01

116

Nucleon EDM from atomic systems and constraints on supersymmetry parameters  

International Nuclear Information System (INIS)

The nucleon EDM is shown to be directly related to the EDM of atomic systems. From the observed EDM values of the atomic Hg system, the neutron EDM can be extracted, which gives a very stringent constraint on the supersymmetry parameters. It is also shown that the measurement of Nitrogen and Thallium atomic systems should provide important information on the flavor dependence of the quark EDM. We perform numerical analyses on the EDM of neutron, proton and electron in the minimal supersymmetric standard model with CP-violating phases. We demonstrate that the new limit on the neutron EDM extracted from atomic systems excludes a wide parameter region of supersymmetry breaking masses above 1 TeV, while the old limit excludes only a small mass region below 1 TeV. (author)

117

Nucleon Edm from Atomic Systems and Constraints on Supersymmetry Parameters  

CERN Document Server

The nucleon EDM is shown to be directly related to the EDM of atomic systems. From the observed EDM values of the atomic Hg system, the neutron EDM can be extracted, which gives a very stringent constraint on the supersymmetry parameters. It is also shown that the measurement of Nitrogen and Thallium atomic systems should provide important information on the flavor dependence of the quark EDM. We perform numerical analyses on the EDM of neutron, proton and electron in the minimal supersymmetric standard model with CP-violating phases. We demonstrate that the new limit on the neutron EDM extracted from atomic systems excludes a wide parameter region of supersymmetry breaking masses above 1 TeV, while the old limit excludes only a small mass region below 1 TeV.

Oshima, S; Fujita, T; Oshima, Sachiko; Nihei, Takeshi; Fujita, Takehisa

2005-01-01

118

Current trends in searches for new physics using measurements of parity violation and electric dipole moments in atoms and molecules  

CERN Document Server

We review current status of the study of parity and time invariance phenomena in atoms, nuclei and molecules. We focus on three most promising areas of research: (i) parity non-conservation in a chain of isotopes, (ii) search for nuclear anapole moments, and (iii) search for permanent electric dipole moments (EDM) of atoms and molecules which are caused by either, electron EDM or nuclear $T,P$-odd moments such as nuclear EDM and nuclear Schiff moment.

Dzuba, V A

2010-01-01

119

Review of EDM experiments  

Science.gov (United States)

The current limits on physics beyond the SM come in large part from the non-observation of EDMs in the sensitive electric dipole moment experiments, like the neutron, 199Hg, and 205Tl. New systems with enhanced EDM sensitivity are coming online and promise a resolution of the baryon asymmetry of our universe (if an EDM is observed) or a severe constraint on physics beyond the SM by the end of the current decade.

Semertzidis, Yannis K.

2011-12-01

120

The ACME electron electric dipole moment search  

Science.gov (United States)

Observation of a non-zero electric dipole moment (EDM) of the electron, de, within a few orders of magnitude of the current limit |de| thorium monoxide (ThO) molecules. In this molecule, the EDM experiences a large electric field (˜ 00 GV/cm) that amplifies the spin precession. In addition, several properties of the molecular state make it possible to suppress many anticipated sources of systematic error. Our experiment uses a slow, cryogenic molecular beam to achieve unprecedented statistical accuracy. We now routinely take data with a 1? statistical uncertainty of ?de 1.0-1.5 x10-28/?T e.cm, where T is the running time in days. We will present the current status of the experiment.

Demille, David

2013-04-01

121

The Neutron EDM Experiment  

CERN Document Server

The neutron EDM experiment has played an important part over many decades in shaping and constraining numerous models of CP violation. This review article discusses some of the techniques used to calculate EDMs under various theoretical scenarios, and highlights some of the implications of EDM limits upon such models. A pedagogical introduction is given to the experimental techniques employed in the recently completed ILL experiment, including a brief discussion of the dominant systematic uncertainties. A new and much more sensitive version of the experiment, which is currently under development, is also outlined.

Harris, P G

2007-01-01

122

On the EDM Cancellations in D-brane models  

OpenAIRE

We analyze the possibility of simultaneous electron, neutron, and mercury electric dipole moment (EDM) cancellations in the mSUGRA and D--brane models. We find that the mercury EDM constraint practically rules out the cancellation scenario in D-brane models whereas in the context of mSUGRA it is still allowed with some fine-tuning.

Abel, S.; Khalil, S.; Lebedev, O.

2001-01-01

123

PLANS FOR A NEUTRON EDM EXPERIMENT AT SNS  

Energy Technology Data Exchange (ETDEWEB)

The electric dipole moment of the neutron, leptons, and atoms provide a unique window to Physics Beyond the Standard Model. They are currently developing a new neutron EDM experiment (the nEDM Experiment). This experiment, which will be run at the 8.9 {angstrom} Neutron Line at the Fundamental Neutron Physics Beamline (FNPB) at the Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory, will search for the neutron EDM with a sensitivity two orders of magnitude higher than the present limit. In this paper, the motivation for the experiment, the experimental method, and the present status of the experiment are discussed.

ITO, TAKEYASU [Los Alamos National Laboratory

2007-01-31

124

CKM benchmarks for electron electric dipole moment experiments  

Science.gov (United States)

All current experiments searching for an electron electric dipole moment (EDM) de are performed with atoms and diatomic molecules. Motivated by significant recent progress in searches for an EDM-type signal in diatomic molecules with an uncompensated electron spin, we provide an estimate for the expected signal in the Standard Model due to the Cabibbo-Kobayashi-Maskawa (CKM) phase. We find that the main contribution originates from the effective electron-nucleon operator e¯i?5eN¯N, induced by a combination of weak and electromagnetic interactions at O(GF2?2), and not by the CKM-induced electron EDM itself. When the resulting atomic P ,T-odd mixing is interpreted as an equivalent electron EDM, this estimate leads to the benchmark deequiv(CKM)˜10-38 ecm.

Pospelov, Maxim; Ritz, Adam

2014-03-01

125

Advances in the EDM-DEDM procedure.  

Science.gov (United States)

The DEDM (difference electron-density modification) algorithm has been described in a recent paper [Caliandro et al. (2008), Acta Cryst. A64, 519-528]: it breaks down the collinearity between model structure phases and difference structure phase estimates. The new difference electron-density produced by DEDM, summed to the calculated Fourier maps, is expected to provide a representation of the full structure that is more accurate than that obtained by the observed Fourier synthesis. In the same paper, the DEDM algorithm was combined with the EDM (electron-density modification) approach to give the EDM-DEDM procedure which, when applied to practical molecular-replacement cases, was able to improve the model structures. In this paper, it is shown that EDM-DEDM suffers from some critical points that did not allow cyclical application of the procedure. These points are identified and modifications are made to allow iteration of the procedure. The applications indicate that EDM-DEDM may become a fundamental tool in protein crystallography. PMID:19237747

Caliandro, Rocco; Carrozzini, Benedetta; Cascarano, Giovanni Luca; Giacovazzo, Carmelo; Mazzone, Anna Maria; Siliqi, Dritan

2009-03-01

126

Prospective candidates for the EDM experiments of new type: calculations of enhancement of P,T-odd effects in HI+ and liquid Xe  

International Nuclear Information System (INIS)

The search for the P,T-parity non-conservation (PNC) effects is of fundamental importance in physics. Experiments are performed on T1F and YbF, and are prepared on PbO and HgH molecules. Recently some new approaches were suggested, such as the search for P,T-odd effects in liquid xenon and on HI+ molecular ion. For preparation and interpretation of these experiments high-precision calculations of the electronic structure are required. Recently developed theoretical methods allow one to analyze the atomic-molecular systems from the point of enhancement of P,T-odd effects and recommend such or another system as a prospective candidate. We calculated enhancement factor for electron EDM in the ground state of HI+ molecular ion, required for experiment of new type on electron EDM search. The results of calculations of P,T-odd effects in liquid xenon are also discussed

127

Permanent Electron Electric Dipole Moment Search in the X^3?_1 Ground State of Tungsten Carbide Molecules  

Science.gov (United States)

We are developing an experiment to search for the permanent electric dipole moment (EDM) of the electron using the valence electrons in the X^3?_1 ground state of Tungsten Carbide (WC) molecules. Currently, we are detecting the molecules by Laser Induced Fluorescence spectroscopy at ˜75cm downstream of a pulsed ablation beam source. We have a detection rate of ˜10 182W12C molecules/second in X^3?_1, v"=0, J"=1 state with geometric detection efficiency of 0.004. A continuous WC molecular beam is under development. Additionally, preliminary measurements of the 183W12C hyperfine structure will be presented.

Lee, Jeongwon; Chen, Jinhai; Leanhardt, Aaron

2011-06-01

128

EDM-DEDM and protein crystal structure solution.  

Science.gov (United States)

Electron-density modification (EDM) procedures are the classical tool for driving model phases closer to those of the target structure. They are often combined with automated model-building programs to provide a correct protein model. The task is not always performed, mostly because of the large initial phase error. A recently proposed procedure combined EDM with DEDM (difference electron-density modification); the method was applied to the refinement of phases obtained by molecular replacement, ab initio or SAD phasing [Caliandro, Carrozzini, Cascarano, Giacovazzo, Mazzone & Siliqi (2009), Acta Cryst. D65, 249-256] and was more effective in improving phases than EDM alone. In this paper, a novel fully automated protocol for protein structure refinement based on the iterative application of automated model-building programs combined with the additional power derived from the EDM-DEDM algorithm is presented. The cyclic procedure was successfully tested on challenging cases for which all other approaches had failed. PMID:19390153

Caliandro, Rocco; Carrozzini, Benedetta; Cascarano, Giovanni Luca; Giacovazzo, Carmelo; Mazzone, Anna Maria; Siliqi, Dritan

2009-05-01

129

Wire EDM for Refractory Materials  

Science.gov (United States)

In an attempt to reduce fabrication time and costs, Wire Electrical Discharge Machine (Wire EDM) method was investigated as tool for fabricating matched blade roots and disk slots. Eight high-strength nickel-base superalloys were used. Computer-controlled Wire EDM technique provided high quality surfaces with excellent dimensional tolerances. Wire EDM method offers potential for substantial reductions in fabrication costs for "hard to machine" alloys and electrically conductive materials in specific high-precision applications.

Zellars, G. R.; Harris, F. E.; Lowell, C. E.; Pollman, W. M.; Rys, V. J.; Wills, R. J.

1982-01-01

130

Communication: Theoretical study of ThO for the electron electric dipole moment search  

Energy Technology Data Exchange (ETDEWEB)

An experiment to search for the electron electric dipole moment (eEDM) on the metastable H{sup 3}?{sub 1} state of ThO molecule was proposed and now prepared by the ACME Collaboration [ http://www.electronedm.org ]. To interpret the experiment in terms of eEDM and dimensionless constant k{sub T,} {sub P} characterizing the strength of the T,P-odd pseudoscalar–scalar electron–nucleus neutral current interaction, an accurate theoretical study of an effective electric field on electron, E{sub eff}, and a parameter of the T,P-odd pseudoscalar–scalar interaction, W{sub T,} {sub P}, in ThO is required. We report our results for E{sub eff} (84 GV/cm) and W{sub T,} {sub P} (116 kHz) together with the hyperfine structure constant, molecule frame dipole moment, and H{sup 3}?{sub 1} ? X{sup 1}?{sup +} transition energy, which can serve as a measure of reliability of the obtained E{sub eff} and W{sub T,} {sub P} values. Besides, our results include a parity assignment and evaluation of the electric-field dependence for the magnetic g factors in the ?-doublets of H{sup 3}?{sub 1}.

Skripnikov, L. V., E-mail: leonidos239@gmail.com; Petrov, A. N.; Titov, A. V. [Federal State Budgetary Institute “Petersburg Nuclear Physics Institute,” Gatchina, Leningrad district 188300 (Russian Federation); Department of Physics, Saint Petersburg State University, Saint Petersburg, Petrodvoretz 198904 (Russian Federation)

2013-12-14

131

Communication: Theoretical study of ThO for the electron electric dipole moment search  

International Nuclear Information System (INIS)

An experiment to search for the electron electric dipole moment (eEDM) on the metastable H3?1 state of ThO molecule was proposed and now prepared by the ACME Collaboration [ http://www.electronedm.org ]. To interpret the experiment in terms of eEDM and dimensionless constant kT,P characterizing the strength of the T,P-odd pseudoscalar–scalar electron–nucleus neutral current interaction, an accurate theoretical study of an effective electric field on electron, Eeff, and a parameter of the T,P-odd pseudoscalar–scalar interaction, WT,P, in ThO is required. We report our results for Eeff (84 GV/cm) and WT,P (116 kHz) together with the hyperfine structure constant, molecule frame dipole moment, and H3?1 ? X1?+ transition energy, which can serve as a measure of reliability of the obtained Eeff and WT,P values. Besides, our results include a parity assignment and evaluation of the electric-field dependence for the magnetic g factors in the ?-doublets of H3?1

132

A search for nEDM and new constraints on short-range “pseudo-magnetic” interaction using neutron optics of noncentrosymmetric crystal  

Energy Technology Data Exchange (ETDEWEB)

New approach to measure both neutron electric dipole moment (EDM) and short-range pseudomagnetic nucleon-nucleon interaction using neutron optics of a crystal without center of symmetry is presented. This approach allows getting best direct constraint on the parameters of short range pseudomagnetic interaction of a free neutron with matter for the range of interaction distances ?<10{sup -7} m.

Fedorov, V.V., E-mail: vvv@pnpi.spb.ru; Kuznetsov, I.A.; Voronin, V.V.

2013-08-15

133

New Experimental Limit on the Electric Dipole Moment of the Electron in a Paramagnetic Insulator  

OpenAIRE

We report results of an experimental search for the intrinsic Electric Dipole Moment (EDM) of the electron using a solid-state technique. The experiment employs a paramagnetic, insulating gadolinium gallium garnet (GGG) that has a large magnetic response at low temperatures. The presence of the eEDM would lead to a small but non-zero magnetization as the GGG sample is subject to a strong electric field. We search for the resulting Stark-induced magnetization with a sensitive...

Kim, Y. J.; Liu, C. -y; Lamoreaux, S. K.; Visser, G.; Matlashov, A. V.; Kunkler, B.

2011-01-01

134

Multiconfiguration Dirac-Hartree-Fock calculations of EDM for Ra, Hg, Yb  

Science.gov (United States)

Using multiconfiguration Dirac-Hartree-Fock (MCDHF) method, we calculated the atomic electric dipole moment (EDM) for Ra, Hg, Yb, arising from nuclear Schiff moment, (P,T)-odd electron-nucleon interactions, and interaction of electron EDM with nuclear electromagnetic field.

Gaigalas, Gediminas; Biero?, Jacek; Radži?t?, Laima

2014-04-01

135

Making EDM Electrodes By Stereolithography  

Science.gov (United States)

Stereolithography is computer-aided manufacturing technique. Used to make models and molds of electrodes for electrical-discharge machining (EDM). Eliminates intermediate steps in fabrication of plastic model of object used in making EDM electrode to manufacture object or mold for object.

Barlas, Philip A.

1988-01-01

136

Prospects for an electron electric dipole moment search in metastable ThO and ThF$^{\\rm +}$  

OpenAIRE

The observation of an electron electric dipole moment (eEDM) would have major ramifications for the standard model of physics. Polar molecules offer a near-ideal laboratory for such searches due to the large effective electric field (${\\bf F}_{\\rm eff}$), on order of tens of GV/cm that can be easily oriented in the lab frame. We present an improved method for simply and accurately determining ${\\bf F}_{\\rm eff}$, in a heavy polar molecule, allowing for a quick determination ...

Meyer, Edmund; Bohn, John

2008-01-01

137

An uncompensated magnetic field drifts in a search for an electric dipole moment of the neutron (nEDM) carrying out at Paul Scherrer Institute (PSI)  

International Nuclear Information System (INIS)

Full text: In order to reach the desired sensitivity goal 5×10-27 e·cm (95% C.L.), the systematic uncertainties must be smaller than 1.3×10-27 e·cm. The uncompensated field drift is one of the major systematic error in the nEDM experiment. Charging current of electric field reversals may cause a change in the magnetic field gradient which might result in a false EDM signal. A set of cesium magnetometers are used to measure the change in the vertical magnetic field gradients. This effect was experimentally studied in December 2012 during 20 days. More than a thousand electric field reversals were used for the analysis presented in this talk. (author)

138

EMERSE: The Electronic Medical Record Search Engine  

OpenAIRE

EMERSE (The Electronic Medical Record Search Engine) is an intuitive, powerful search engine for free-text documents in the electronic medical record. It offers multiple options for creating complex search queries yet has an interface that is easy enough to be used by those with minimal computer experience. EMERSE is ideal for retrospective chart reviews and data abstraction and may have potential for clinical care as well.

Hanauer, David A.

2006-01-01

139

Search for the electric dipole moment of the electron with thorium monoxide  

OpenAIRE

The electric dipole moment of the electron (eEDM) is a signature of CP-violating physics beyond the Standard Model. We describe an ongoing experiment to measure or set improved limits to the eEDM, using a cold beam of thorium monoxide (ThO) molecules. The metastable \\(H\\) \\(^{3}\\)\\(\\Delta\\)\\(_{ 1}\\) state in ThO has important advantages for such an experiment. We argue that the statistical uncertainty of an eEDM measurement could be improved by as much as 3 orders of magnitude compared to the...

Campbell, Wesley; Demille, David; Vultha, Amar; Gurevich, Yulia Vsevolodovna; Hutzler, Nicholas Richard; Parsons, Maxwell Fredrick; Patterson, David; Petrik, Elizabeth Sarah; Spaun, Benjamin Norman; Gabrielse, Gerald; Doyle, John M.

2009-01-01

140

Towards a new measurement of the neutron EDM - The nEDM experiment at PSI/TUM  

International Nuclear Information System (INIS)

Since the 1950's people search for electric dipole moments (EDM) of fundamental systems, an unambiguous manifestation of parity (P) and time reversal symmetry (T) - and therefore CP-violation. Whereas EDMs predicted by the Standard Model (SM) of particle physics are very small, most SM extensions (e.g. Supersymmetry) require large EDMs. These models are already strongly limited by experiments, and a further improvement of the sensitivity of these measurements can provide a unique opportunity to search for new physics. Speaking for the n-EDM collaboration based at PSI and TUM, I present an approach to measure the EDM of the neutron with an accuracy of 5.1028 e.cm or better, corresponding to an increase in sensitivity of nearly two orders of magnitude over the current limits. To achieve this goal, (i) new strong sources of ultra-cold neutrons are being built, as well as (ii) improved control of magnetic fields and (iii) means to control systematic effects is investigated. The final sensitivity goal will be reached in phases, (i) optimizing the existing room temperature apparatus of the former RAL/Sussex/ILL collaboration and gradually implementing new components (2008), (ii) improving the current limits by a factor of 4 by operating the improved apparatus at the strong UCN source at PSI (2009-2010) and (iii) operating a large scale spectrometer to reach the sensitivity goal (2011+)

141

Laser Cooled Francium Factory for the Electron Electric Dipole Moment Search  

Science.gov (United States)

A permanent electric dipole moment (EDM) of an elementary particle is a candidate observable exhibiting CP violation beyond the standard model. In the present study, we plan to search for the electron EDM in francium (Fr), which is the heaviest alkali atom, captured in a far-off resonance optical trap. Since the number of Fr atoms is essential to high precision measurements, we have developed a cold Fr source called "Laser cooled Fr factory" in order to trap the radioactive Fr produced through a nuclear fusion reaction. The Fr produced was released as an ion from a gold production target in a Fr ion source, transported as an ion beam, and converted from ion to atom in a neutralizer. The neutralized Fr atom will be trapped in a magneto-optical trap(MOT) and then be transferred to an optical dipole trap. The rate of Fr atoms so far achieved was 1 × 106 ions/sec from the ion source and 1 atom/sec of the neutralized Fr atom from the neutralizer. In order to optimize performance of the Fr beam line, Rb atoms were trapped in the MOT. In addition to the beam-line experiment, in an off-line MOT system, polarization gradient cooling was applied to the trapped Rb atoms to cool them down to temperatures lower than the Rb Doppler-cooling limit. In this paper, we describe the present status of this experimental apparatus.

Hayamizu, Tomohiro; Arikawa, Hiroshi; Ezure, Saki; Harada, Ken-ichi; Inoue, Takeshi; Ishikawa, Taisuke; Itoh, Masatoshi; Kato, Tomohiro; Kawamura, Hirokazu; Sato, Tomoya; Ando, Shun; Aoki, Takahiro; Kato, Ko; Uchiyama, Aiko; Aoki, Takatoshi; Furukawa, Takeshi; Hatakeyama, Atsushi; Hatanaka, Kichiji; Imai, Kenichi; Murakami, Tetsuya; Nataraj, Huliyar; Shimizu, Yasuhiro; Wakasa, Tomotsugu; Yoshida, Hidetomo; Sakemi, Yasuhiro

142

Searching for New Physics Beyond the Standard Model in Electric Dipole Moment  

Science.gov (United States)

This is a theoretical review of exploration of new physics beyond the Standard Model (SM) in the electric dipole moment (EDM) in elementary particles, atoms and molecule. EDM is a very important CP violating phenomenon and sensitive to new physics. Starting with the estimations of EDM of quarks-leptons in SM, we explore new signals beyond SM. However, these works drive us to wider frontiers where we search fundamental physics using atoms and molecules and vice versa. Paramagnetic atoms and molecules have great enhancement factor on electron EDM. Diamagnetic atoms and molecules are very sensitive to nuclear P and T odd processes. Thus EDM becomes the keyword not only of New Physics but also of unprecedented fruitful collaborations among particle, atomic and molecular physics. This review intends to help such collaborations over a wide range of physicists.

Fukuyama, Takeshi

2012-06-01

143

Gadolinium Iron Garnet as a Solid State Material for an Electron Electric Dipole Moment Search  

OpenAIRE

The possibility of a solid state electron electric dipole moment (EDM) experiment based on Gadolinium Iron Garnet (GdIG) is investigated. GdIG appears to exhibit superparamagnetism and this effect can be used to enhance the electric-field-induced EDM signal at relatively a high temperatures, as compared to a simple paramagnetic system such as Gadolinium Gallium Garnet. The sensitivity of a GdIG based experiment might be large enough that an improvement by over three orders o...

Lamoreaux, Steve K.

2007-01-01

144

Bacillus subtilis EdmS (formerly PgsE) participates in the maintenance of episomes.  

Science.gov (United States)

Extrachromosomal DNA maintenance (EDM) is an important process in molecular breeding and for various applications in the construction of genetically engineered microbes. Here we describe a novel Bacillus subtilis gene involved in EDM function called edmS (formerly pgsE). Functional gene regions were identified using molecular genetics techniques. We found that EdmS is a membrane-associated protein that is crucial for EDM. We also determined that EdmS can change a plasmid vector with an unstable replicon and worse-than-random segregation into one with better-than-random segregation, suggesting that the protein functions in the declustering and/or partitioning of episomes. EdmS has two distinct domains: an N-terminal membrane-anchoring domain and a C-terminal assembly accelerator-like structure, and mutational analysis of edmS revealed that both domains are essential for EDM. Further studies using cells of Bacillus megaterium and itsedmS (formerly capE) gene implied that EdmS has potential as a molecular probe for exploring novel EDM systems. PMID:23583563

Ashiuchi, Makoto; Yamashiro, Daisuke; Yamamoto, Kento

2013-09-01

145

Distinguishing axions from generic light scalars using EDM and fifth-force experiments  

CERN Document Server

We derive electric dipole moment (EDM) constraints on possible new macroscopic time reversal and parity violating (TVPV) spin-dependent forces. These constraints are compared to those derived from direct searches in fifth-force experiments and from combining laboratory searches with astrophysical bounds on stellar energy loss. For axion-mediated TVPV spin-dependent forces, EDM constraints dominate over fifth-force limits by several orders of magnitude. However, we show that for a generic light scalar, unrelated to the strong CP problem, present bounds from direct fifth- force searches are more stringent than those inferred from EDM limits, for the interaction ranges explored by fifth-force experiments. Thus, correlating observations in EDM and fifth-force experiments could help distinguish axions from more generic light scalar scenarios.

Mantry, Sonny; Ramsey-Musolf, Michael J

2014-01-01

146

Trapping Yb Atoms for an EDM Experiment  

Science.gov (United States)

We are investigating the possible use of a magneto-optical trap (MOT) and optical dipole trap to search for the CP-violating permanent electric dipole moment (EDM) by nuclear spin resonance in Yb (ytterbium) atoms. Optical cooling and trapping of Yb offers many advantages for an atomic EDM experiment including long spin-relaxation lifetimes and a zero average motional magnetic field v×E. The ultra-high vacuum necessary for the trap suppresses spurious magnetic fields due to leakage currents and will allow us to apply a high electric field. Similar EDM experiments have been proposed for the trapped heavy atoms Cs and Fr. However, the ^171Yb atoms are free from the large cross-sections for cold atom collisions that limit the sensitivity of the Cs and Fr experiments because Yb is diamagnetic with a spin-1/2 nucleus. We will use the ^1S0 arrow ^1P1 (398.9 nm) transition for cooling and trapping. The ^1P1 state has a relatively short lifetime of 5 ns, allowing a large laser cooling force to be applied to the atoms. The transition is almost a closed 2-state system, minimizing the need for an extra cleanup laser. We have frequency doubled a Ti:Sapphire laser with an LBO crystal to 398.9 nm and have observed fluorescence from this transition in a Yb beam. We have completed the initial studies for building the MOT and will discuss further progress and possible future experiments. Further information can be found at ?rb"http://www.phys.washington.edu/r~einam/".

Maruyama, Reina; Fortson, Norval; Romalis, Michael

1998-05-01

147

Evaluation of a possible optical e-EDM measurement  

Science.gov (United States)

Since its proposed existence by Purcell and Ramsey in 1950, the possibility of an electron electric dipole moment (e-EDM) has been the subject of extensive theoretical and experimental investigation. Here we describe an ongoing effort to probe for an e-EDM by measuring the energy difference between two states of the PbF molecule that differ only by their orientation with respect to an applied external electric field. Specifically, we describe a possible optical Ramsey resonance experiment utilizing rotating linearly polarized light. We present initial tests of this scheme, including measurement of a small angle of rotation of a polarized beam splitter and measurement of optical Stark spectroscopy of the PbF molecule. We discuss these results and the limitations they place on a measurement of an e-EDM.

Fan, Haoquan; Coker, James; Yang, Tao Zh.; Gillean, Jerry; Shafer-Ray, N. E.

2011-06-01

148

Muonium production target for the muon g-2/EDM experiment at J-PARC  

Science.gov (United States)

There is more than three standard-deviations discrepancy between measurement and theoretical prediction of the muon anomalous magnetic moment. We are going to measure the precision value of muon g - 2 and search for physics beyond standard model. In addition, we can search for muon EDM which violates CP symmetry. CP violation in charged lepton sector is currently not found. We are developing the 'Ultra Cold Muon Beam' instead of tertiary muon beam with electric focusing. Ultra cold muon is realized by laser ionization of muonium (bound state of a muon and an electron) from the production target. Increase of muonium yield is essential for our experimental goal; 0.1ppm statistical precision. Muonium production experiment at J-PARC MLF MUSE is planned in 2012 autumn. In this paper, we discuss the development of muonium production target and positron detector for the study.

Kanda, Sohtaro

2014-08-01

149

Electronic biomedical literature search for budding researcher.  

Science.gov (United States)

Search for specific and well defined literature related to subject of interest is the foremost step in research. When we are familiar with topic or subject then we can frame appropriate research question. Appropriate research question is the basis for study objectives and hypothesis. The Internet provides a quick access to an overabundance of the medical literature, in the form of primary, secondary and tertiary literature. It is accessible through journals, databases, dictionaries, textbooks, indexes, and e-journals, thereby allowing access to more varied, individualised, and systematic educational opportunities. Web search engine is a tool designed to search for information on the World Wide Web, which may be in the form of web pages, images, information, and other types of files. Search engines for internet-based search of medical literature include Google, Google scholar, Scirus, Yahoo search engine, etc., and databases include MEDLINE, PubMed, MEDLARS, etc. Several web-libraries (National library Medicine, Cochrane, Web of Science, Medical matrix, Emory libraries) have been developed as meta-sites, providing useful links to health resources globally. A researcher must keep in mind the strengths and limitations of a particular search engine/database while searching for a particular type of data. Knowledge about types of literature, levels of evidence, and detail about features of search engine as available, user interface, ease of access, reputable content, and period of time covered allow their optimal use and maximal utility in the field of medicine. Literature search is a dynamic and interactive process; there is no one way to conduct a search and there are many variables involved. It is suggested that a systematic search of literature that uses available electronic resource effectively, is more likely to produce quality research. PMID:24179937

Thakre, Subhash B; Thakre S, Sushama S; Thakre, Amol D

2013-09-01

150

Solid-state systems for the electron electric dipole moment and other fundamental measurements  

International Nuclear Information System (INIS)

In 1968, Shapiro published the suggestion that one could search for an electron dipole moment (EDM) by applying a strong electric field to a substance that has an unpaired electron spin; at low temperature, the EDM interaction would lead to a net sample magnetization that can be detected with a superconducting quantum interference device (SQUID) magnetometer. One experimental EDM search based on this technique was published, and for a number of reasons including high sample conductivity, high operating temperature, and limited SQUID technology, the result was not particularly sensitive compared to other experiments in the late 1970s. Advances in SQUID and conventional magnetometery led us to reconsider this type of experiment, which can be extended to searches and tests other than EDMs (e.g., test of Lorentz invariance). In addition, the complementary measurement of an EDM-induced sample electric polarization due to application of a magnetic field to a paramagnetic sample might be effective using modern ultrasensitive charge measurement techniques. A possible paramagnetic material is Gd-substituted yttrium iron garnet which has very low conductivity and a net enhancement (atomic enhancement times crystal screening) of order unity. Use of a reasonable volume (hundreds of cm3) sample of this material at 50 mK and 10 kV/cm might yield an EDM sensitivity of 10-32 e cm or better, a factor of 105 improvement over current experimental limitsrovement over current experimental limits

151

Relations between matrix elements of different weak interactions and interpretation of the PNC and EDM measurements in atoms and molecules  

CERN Document Server

The relations between matrix elements of different P- and T-odd weak interactions are derived. We demonstrate that similar relations hold for parity nonconserving (PNC) transition amplitudes and electron electric dipole moments (EDM) of atoms and molecules. This allows to express P- and T-odd effects in many-electron systems caused by different symmetry-breaking mechanisms via each other using simple analytical formulas. We use these relations for the interpretation of the anapole moment measurements in cesium and thallium and for the analysis of the relative contributions of the scalar-pseudoscalar CP-odd weak interaction and electron EDM to the EDM of Cs, Tl, Fr and other atoms and many polar molecules (YbF, PbO, ThO, etc.). Model-independent limits on electron EDM and the parameter of the scalar-pseudoscalar CP-odd interaction are found from the analysis of the EDM measurements for Tl and YbF.

Dzuba, V A; Harabati, C

2011-01-01

152

Gadolinium Iron Garnet as a Solid State Material for an Electron Electric Dipole Moment Search  

CERN Document Server

The possibility of a solid state electron electric dipole moment (EDM) experiment based on Gadolinium Iron Garnet (GdIG) is investigated. GdIG appears to exhibit superparamagnetism and this effect can be used to enhance the electric-field-induced EDM signal at relatively a high temperatures, as compared to a simple paramagnetic system such as Gadolinium Gallium Garnet. The sensitivity of a GdIG based experiment might be large enough that an improvement by over three orders of magnitude, compared to the existing electron EDM limit, could be obtained at a modest temperature of 4 K, assuming that the superparamagnetic effect is not suppressed at this temperature, and that the spin relaxation time remains sufficiently rapid.

Lamoreaux, S K

2007-01-01

153

Permanent EDM measurement in Cs using nonlinear magneto-optic rotation  

CERN Document Server

We use the technique of chopped nonlinear magneto-optic rotation in a paraffin-coated Cs vapor cell to look for a permanent electric dipole moment (EDM) in the atom. The signature of the EDM is a shift in the Larmor precession frequency correlated with application of an electric field. Using a field of 2.6 kV/cm, we place an upper limit on the electron EDM of $ 7.7 \\times 10^{-22} $ e-cm. This limit can be improved by 5 to 6 orders-of-magnitude (and brought below the current best experimental limit) with simple improvements to the technique.

Ravi, Harish; Natarajan, Vasant

2015-01-01

154

Search for resonant double-electron capture  

International Nuclear Information System (INIS)

It is still unknown whether neutrinos are Dirac or Majorana particles. An answer to this question can be obtained from neutrinoless double-electron capture. An observation of this process would prove that the neutrino is a Majorana particle. A measurement of the half-life of this process would allow a determination of the effective Majorana neutrino mass. In the search for the nuclide with the largest probability for neutrinoless double-electron capture, we have determined the Q-values of several potentially suitable nuclides with SHIPTRAP by Penning-trap mass-ratio measurements. The ECEC-transition in 152Gd has been determined to have the smallest half-life of 1026 years for a 1 eV neutrino mass among all known 0?ECEC-transitions, which makes 152Gd the most promising candidate for the search for neutrino-less double electron capture. This contribution summarizes the recent experimental results.

155

Corrosion Resistance Analysis of Sintered NdFeB Magnets Using Ultrasonic-Aided EDM Method  

Science.gov (United States)

Sintered neodymium-iron-boron (NdFeB) permanent magnets are widely used in many fields because of their excellent magnetic property. However, their poor corrosion resistance has been cited as a potential problem that limits their extensive application. This paper presents an experimental investigation into the improvement of surface corrosion resistance with the ultrasonic-aided electrical discharge machining (U-EDM) method. A scanning electron microscope was used to analyze the surface morphology of recast layers formed through the EDM and U-EDM processes. The chemical structure and elements of these recast layers were characterized using x-ray diffraction and energy dispersive spectroscopy. Corrosion resistance was also studied by means of potentiodynamic polarization, electrochemical impedance spectroscopy, and immersion tests in 0.5 mol/L H2SO4 solution. Experimental results show that an amorphous structure was formed in the recast layer during the EDM and U-EDM processes and that this structure could improve the corrosion resistance of sintered NdFeB magnets. Moreover, the corrosion resistance of U-EDM-treated surface was better than that of the EDM-treated surface.

Li, L.; Wei, X. T.; Li, Z. Y.; Cheng, X.

2015-01-01

156

An experimental search for the electron Electric Dipole Moment in Gadolinium Gallium Garnet  

Science.gov (United States)

A discovery of a permanent electric dipole moment of the electron (eEDM) would provide crucial information about the nature of T-violation and imply new sources of CP-violation beyond the Standard Model. While the leading experimental technique used to measure EDM is based on the nuclear magnetic resonance, we are pursuing research that would improve the present experimental limit of the eEDM using a new technique in solid-state systems at low temperatures. The experiment uses a paramagnetic insulator Gadolinium Gallium Garnet with a large magnetic response. The presence of the eEDM leads to a finite magnetization when the garnet sample is subjected to a strong electric field. The resulting magnetization can be measured using the Superconducting Quantum Interference Device (SQUID) as a sensitive magnetometer. In this talk, we will discuss the progress to control the systematic effects and improve the sensitivity. The major efforts include the design and implementation of a 24-bit data acquisition system with ultra-low level of channel crosstalk, and the control of the high voltage drift from the supply. With these considerable progresses, we report our first background-free experimental limit of the eEDM on the order of 10-24 e.cm .

Kim, Young Jin; Liu, Chen-Yu

2011-04-01

157

Search for the electric dipole moment of the electron with ThO  

Science.gov (United States)

The thorium monoxide (ThO) molecule in its metastable H state has been identified as a promising system for measuring the permanent electric dipole moment of the electron (eEDM). We have begun an experiment to measure the eEDM using a high flux, cryogenic beam of ThO. We report our progress, including the production of cold ThO beams with an observed flux of 2 x10^9 molecules per ablation shot. We also demonstrate optical pumping of molecules into the H state, which allows us to make a more accurate determination of the H state lifetime.

Gurevich, Yulia V.; Campbell, Wesley C.; Demille, David; Doyle, John M.; Gabrielse, Gerald; Hutzler, Nicholas; Parsons, Maxwell; Spaun, Benjamin; Vutha, Amar C.

2009-05-01

158

Complementarity of LHC and EDMs for Exploring Higgs CP Violation  

CERN Document Server

We analyze the constraints on a CP-violating, flavor conserving, two Higgs doublet model from the measurements of Higgs properties and from the search for heavy Higgs bosons at LHC, and show that the stronger limits typically come from the heavy Higgs search channels. The limits on CP violation arising from the Higgs sector measurements are complementary to those from EDM measurements. Combining all current constraints from low energy to colliders, we set generic upper bounds on the CP violating angle which parametrizes the CP odd component in the 126 GeV Higgs boson.

Chen, Chien-Yi; Zhang, Yue

2015-01-01

159

Probing charged matter through h ? ??, gamma ray lines, and EDMs  

OpenAIRE

Numerous experiments currently underway offer the potential to indirectly probe new charged particles with masses at the weak scale. For example, the tentative excess in h ? ?? decays and the tentative gamma-ray line in Fermi-LAT data have recently attracted attention as possible one-loop signatures of new charged particles. We explore the interplay between such signals, dark matter direct detection through Higgs exchange, and measurements of the electron EDM, by studying the size of thes...

Fan, Jiji; Reece, Matthew

2013-01-01

160

Improved measurement of the shape of the electron.  

Science.gov (United States)

The electron is predicted to be slightly aspheric, with a distortion characterized by the electric dipole moment (EDM), d(e). No experiment has ever detected this deviation. The standard model of particle physics predicts that d(e) is far too small to detect, being some eleven orders of magnitude smaller than the current experimental sensitivity. However, many extensions to the standard model naturally predict much larger values of d(e) that should be detectable. This makes the search for the electron EDM a powerful way to search for new physics and constrain the possible extensions. In particular, the popular idea that new supersymmetric particles may exist at masses of a few hundred GeV/c(2) (where c is the speed of light) is difficult to reconcile with the absence of an electron EDM at the present limit of sensitivity. The size of the EDM is also intimately related to the question of why the Universe has so little antimatter. If the reason is that some undiscovered particle interaction breaks the symmetry between matter and antimatter, this should result in a measurable EDM in most models of particle physics. Here we use cold polar molecules to measure the electron EDM at the highest level of precision reported so far, providing a constraint on any possible new interactions. We obtain d(e) = (-2.4?±?5.7(stat)?±?1.5(syst))?×?10(-28)e?cm, where e is the charge on the electron, which sets a new upper limit of |d(e)|?electron is spherical at this improved level of precision. Our measurement of atto-electronvolt energy shifts in a molecule probes new physics at the tera-electronvolt energy scale. PMID:21614077

Hudson, J J; Kara, D M; Smallman, I J; Sauer, B E; Tarbutt, M R; Hinds, E A

2011-05-26

161

TaN molecule as a candidate to search for New physics  

CERN Document Server

TaN molecule is probably the best candidate to search for T,P-violating nuclear magnetic quadrupole moment (MQM), it also looks promissing to search for other T,P-odd effects. We report results of coupled-cluster calculations of T,P-odd effects in TaN produced by the Ta nucleus MQM, electron electric dipole moment (EDM), scalar$-$pseudoscalar nucleus$-$electron interactions, also of the molecule-axis hyperfine structure constant and dipole moment. Nuclear calculations of $^{181}$Ta MQM are performed to express the T,P-odd effect in terms of the strength constants of T,P-odd nuclear forces, proton and neutron EDM, QCD parameter $\\theta$ and quark chromo-EDM.

Skripnikov, L V; Mosyagin, N S; Titov, A V; Flambaum, V V

2015-01-01

162

Progress toward a measurement of the electron's electric dipole moment using PbO  

Science.gov (United States)

Searches for permanent electric dipole moments (EDMs) of fundamental particles provide a way to detect new sources of time-reversal symmetry violation. We present recent results on an experiment to search for the electron's EDM, using the polar molecule PbO. PbO offers several advantages compared to atoms, including a much larger effective internal electric field (>10 GV/cm) and parity doubling, which can be used to reverse the effective internal electric field without reversing the laboratory electric field. This technique allows for significant rejection of systematic errors. Recent improvements to the experiment have resulted in statistical sensitivities of approximately 1 x10-27 ecm/?day, which could allow for an improvement over the current experimental limit on the electron EDM in only a few days of integration time. Details of the approach and studies of possible systematic errors will be described.

Eckel, Stephen; Hamilton, Paul; Kirilov, Emil; Smith, Hunter; Demille, David

2012-06-01

163

Configuration interaction calculation of hyperfine and P,T-odd constants on ^{207}PbO excited states for the electron EDM experiments  

OpenAIRE

We report first configuration interaction calculations of hyperfine constants A_\\parallel and the effective electric field W_d acting on the electric dipole moment of the electron, in two excited electronic states of ^{207}PbO. The obtained hyperfine constants, A_\\parallel = -3826 MHz for the a(1) state and A_\\parallel = 4887 MHz for the B(1) state, are in very good agreement with the experimental data, -4113 MHz and 5000 \\pm 200 MHz, respectively. We find W_d = -(6.1 ^{+1.8...

Petrov, A. N.; Titov, A. V.; Isaev, T. A.; Mosyagin, N. S.; Demille, D.

2004-01-01

164

Theoretical study of thorium monoxide for the electron electric dipole moment search, II: Electronic properties of $H^3\\Delta_1$ in ThO  

OpenAIRE

Recently an improved limits on the electron electric dipole moment, \\eEDM, and dimensionless constant, $k_{T,P}$, characterizing the strength of the T,P-odd pseudoscalar$-$scalar electron$-$nucleus neutral current interaction in the $H^3\\Delta_1$ state of ThO molecule were obtained by ACME collaboration [Science 343, 269 (2014)]. The interpretation of the experiment in terms of fundamental quantities \\eEDM\\ and $k_{T,P}$ is based on the results of theoretical study of approp...

Skripnikov, L. V.; Titov, A. V.

2014-01-01

165

Improving Electrical Efficiency of Edm Power Supply  

Science.gov (United States)

This paper briefly presents the principal types of Pulse Generators for Electrical Discharge Machining and ways to improve electrical efficiency. A resonant converter with series-parallel LCC circuit, for EDM applications, was analyzed by PSpice simulation. The performances of EDM Power Supply were improved by adding an energy recovering - voltage limiter circuit. The shape of current pulse was changed by adding a supplementary MOSFET Switch in parallel with the gap. Two or more converters can be parallelized, in this way output current can be changed. A bloc-schema was conceived for EDM experimental set up

Toma, Emanoil; Simion, Carmen Mihaela

2014-11-01

166

Search for the electric dipole moment of the electron with thorium monoxide  

CERN Document Server

The electric dipole moment of the electron (eEDM) is a signature of CP-violating physics beyond the Standard Model. We describe an ongoing experiment to measure or set improved limits to the eEDM, using a cold beam of thorium monoxide (ThO) molecules. The metastable $H {}^3\\Delta_1$ state in ThO has important advantages for such an experiment. We argue that the statistical uncertainty of an eEDM measurement could be improved by as much as 3 orders of magnitude compared to the current experimental limit, in a first-generation apparatus using a cold ThO beam. We describe our measurements of the $H$ state lifetime and the production of ThO molecules in a beam, which provide crucial data for the eEDM sensitivity estimate. ThO also has ideal properties for the rejection of a number of known systematic errors; these properties and their implications are described.

Vutha, Amar C; Gurevich, Yulia V; Hutzler, Nicholas R; Parsons, Maxwell; Patterson, David; Petrik, Elizabeth; Spaun, Benjamin; Doyle, John M; Gabrielse, Gerald; DeMille, David

2009-01-01

167

Search for the electric dipole moment of the electron with thorium monoxide  

Science.gov (United States)

The electric dipole moment of the electron (eEDM) is a signature of CP-violating physics beyond the standard model. We describe an ongoing experiment to measure or set improved limits to the eEDM, using a cold beam of thorium monoxide (ThO) molecules. The metastable H 3?1 state in ThO has important advantages for such an experiment. We argue that the statistical uncertainty of an eEDM measurement could be improved by as much as three orders of magnitude compared to the current experimental limit, in a first-generation apparatus using a cold ThO beam. We describe our measurements of the H state lifetime and the production of ThO molecules in a beam, which provide crucial data for the eEDM sensitivity estimate. ThO also has ideal properties for the rejection of a number of known systematic errors; these properties and their implications are described.

Vutha, A. C.; Campbell, W. C.; Gurevich, Y. V.; Hutzler, N. R.; Parsons, M.; Patterson, D.; Petrik, E.; Spaun, B.; Doyle, J. M.; Gabrielse, G.; DeMille, D.

2010-04-01

168

Search for the electric dipole moment of the electron with thorium monoxide  

International Nuclear Information System (INIS)

The electric dipole moment of the electron (eEDM) is a signature of CP-violating physics beyond the standard model. We describe an ongoing experiment to measure or set improved limits to the eEDM, using a cold beam of thorium monoxide (ThO) molecules. The metastable H 3?1 state in ThO has important advantages for such an experiment. We argue that the statistical uncertainty of an eEDM measurement could be improved by as much as three orders of magnitude compared to the current experimental limit, in a first-generation apparatus using a cold ThO beam. We describe our measurements of the H state lifetime and the production of ThO molecules in a beam, which provide crucial data for the eEDM sensitivity estimate. ThO also has ideal properties for the rejection of a number of known systematic errors; these properties and their implications are described.

169

Double core polarization contribution to atomic PNC and EDM calculations  

CERN Document Server

We present a detailed study of the effect of the double core polarization (the polarization of the core electrons due to the simultaneous action of the electric dipole and parity-violating weak fields) for amplitudes of the $ss$ and $sd$ parity non-conserving transitions in Rb, Cs, Ba +, La 2+, Tl, Fr, Ra +, Ac 2+ and Th 3+ as well as electron EDM enhancement factors for the ground states of the above neutral atoms and Au. This effect is quite large and has the potential to resolve some disagreement between calculations in the literature. It also has significant consequences for the use of experimental data in the accuracy analysis.

Roberts, B M; Flambaum, V V

2013-01-01

170

Search For A Permanent Electric Dipole Moment Using Atomic Indium  

OpenAIRE

We propose indium (In) as a possible candidate for observing the permanent electric dipole moment (EDM) arising from the violations of parity (P) and time-reversal (T) symmetries. This atom has been laser cooled and therefore the measurement of its EDM has the potential of improving on the current best EDM limit for a paramagnetic atom which comes from thallium. We report the results of our calculations of the EDM enhancement factor due to the electron EDM and the ratio of t...

Sahoo, B. K.; Pandey, R.; Das, B. P.

2011-01-01

171

Assessment of Powder Mixed EDM: A Review  

Directory of Open Access Journals (Sweden)

Full Text Available This project research undertakes the assessment of powder added electrical discharge machining (PMDM with focus on effect of additive powders and circulation systems. In PMEDM process, powder can be mixed with dielectric fluid either in the main EDM tank or in a separate tank in order to improve EDM machining performance. Different designs of powder mixed EDM circulating systems such as closed and opened systems with different sizes of tank are described in literature. Various devices such as stirrer, circulating pump etc. are placed in the tank in order to ensure the uniformity of powder mixed dielectric. Each design has its advantages and disadvantages and it might affect the EDM output results. Therefore, there is a need to review the PMEDM with respect to additive powders and circulation systems in order to identify the gap and propose an alternative for improving process.

Nanimina Alexis Mouangué

2014-07-01

172

New Year, new interface for EDMS!  

CERN Multimedia

Some of you may already have made the leap to the new EDMS6 interface and be benefitting from the additional functionality and new design it has to offer. But for those who haven’t, you will be able to do so as of Wednesday 28 January when EDMS6 becomes the default interface.    EDMS is the de facto interface for all engineering related data and more. There are currently more than 1.5 million documents and over 2 million files stored there. What’s new in EDMS6? While we have kept the key concepts, we have introduced more functionality and improved navigation within the interface, allowing for better performance to help you in your daily work. We have also added a personal slant to EDMS6 so that you can now customise your list of favourite objects. Modifying data in EDMS is much simpler, allowing you to view all object data in a single window. For example, files can be added to documents with a simple drag and drop and you can now request access to documents...

2015-01-01

173

Progress towards a permanent electron electric dipole moment search using cold atoms in an optical lattice  

Science.gov (United States)

Observation of a permanent electric dipole moment of the electron would imply CP violating effects not contained in the Standard Model. We present our progress towards measuring the electron EDM using laser-cooled cesium and rubidium atoms trapped in a one dimensional optical lattice. We have collected Cs atoms in a MOT and have launched them 90 cm vertically using two cavity-enhanced optical lattice guides. In that region, which is suitable for measurement, we re-cooled and re-trapped the atoms with an overall transfer efficiency from the MOT of 50%. The two 1D lattice traps thread through three specially-coated glass electric field plates. Very low frequency Ramsey-like spectroscopy will be sensitive to an EDM with an ultimate precision of 3x10-30 e-cm.

Solmeyer, Neal E.; Zhu, Kunyan; Weiss, David S.

2011-06-01

174

Study of micro-EDM plasmas  

Science.gov (United States)

Micro Electrical Discharge Machining (micro-EDM) is a plasma-assisted process for the manufacturing of micro-components in high-hardness conductive materials. The removal of material is the result of a sum of dc discharges, produced within a point to plane system of electrodes immersed in a dielectric fluid, whose electric disruption with the development of plasma-currents can be induced by imposing a threshold voltage. To better understand the interaction between the micro-plasma and the material, we have designed and build an experimental setup for the production of single-discharges, characterized by a constant voltage-current operation point. The device allows the ignition of resistive plasmas in air/water at different pulse-times (˜100--3200 ?s), currents (˜1-20 A for ˜75-250 V), polarities and gap-sizes (˜0,5-25 ?m), and the changes in these work conditions can be correlated to the type and size of the craters produced. The micro-plasma electron density ne is measured using the Stark broadening of the H? atomic line. First results give ne ˜ 10^16 -- 10^17 cm^3, in agreement with estimates obtained from an electrical circuit model of the discharge.

Braganca, I. M. F.; Rosa, P. A. R.; Dias, F. M.; Alves, L. L.

2011-11-01

175

New Experimental Limit on the Electric Dipole Moment of the Electron in a Paramagnetic Insulator  

CERN Document Server

We report results of an experimental search for the intrinsic Electric Dipole Moment (EDM) of the electron using a solid-state technique. The experiment employs a paramagnetic, insulating gadolinium gallium garnet (GGG) that has a large magnetic response at low temperatures. The presence of the eEDM would lead to a small but non-zero magnetization as the GGG sample is subject to a strong electric field. We search for the resulting Stark-induced magnetization with a sensitive magnetometer. Recent progress on the suppression of several sources of background allows the experiment to run free of spurious signals at the level of the statistical uncertainties. We report our first limit on the eEDM of $(-5.57 \\pm 7.98 \\pm 0.12)\\times10^{-25}$e$\\cdot$cm with 5 days of data averaging.

Kim, Y J; Lamoreaux, S K; Visser, G; Kunkler, B; Matlashov, A V; Kunkler, B

2011-01-01

176

Broadband velocity modulation spectroscopy of HfF^+: towards a measurement of the electron electric dipole moment  

CERN Document Server

Precision spectroscopy of trapped HfF^+ will be used in a search for the permanent electric dipole moment of the electron (eEDM). While this dipole moment has yet to be observed, various extensions to the standard model of particle physics (such as supersymmetry) predict values that are close to the current limit. We present extensive survey spectroscopy of 19 bands covering nearly 5000 cm^(-1) using both frequency-comb and single-frequency laser velocity-modulation spectroscopy. We obtain high-precision rovibrational constants for eight electronic states including those that will be necessary for state preparation and readout in an actual eEDM experiment.

Cossel, Kevin C; Sinclair, Laura C; Coffey, Tyler; Skripnikov, Leonid V; Petrov, Alexander N; Mosyagin, Nikolai S; Titov, Anatoly V; Field, Robert W; Meyer, Edmund R; Cornell, Eric A; Ye, Jun

2012-01-01

177

Enhanced of the electron electric dipole moment in gadolinium garnets  

International Nuclear Information System (INIS)

Full text: Effects caused by the electron electric dipole moment (EDM) in Gadolinium garnets are considered. Experimental studies of these effects could improve current upper limit on the electron EDM by several orders of magnitude. We suggest a consistent theoretical model and perform calculation of the voltage across a garnet sample induced due to the electron EDM as a response to applied magnetic field

178

Progress towards measuring the electric dipole moment of the electron in metastable PbO  

International Nuclear Information System (INIS)

A permanent electric dipole moment (EDM) of an elementary particle would violate parity and time-reversal symmetries. This has motivated an experiment to search for the EDM of the electron in the metastable excited state a(1)[3?+] of the polar diatomic molecule PbO. A sensitivity to an electron EDM de of 10-29 e·cm appears possible in the short term, representing two orders of magnitude improvement over current limits, with the possibility of 10-31 e·cm sensitivity in the future. Since |de| > 10-31 e·cm is predicted by many theories of physics beyond the standard model, the experiment has the potential to find or exclude new physics. The properties of PbO and techniques required to achieve this sensitivity to new physics are discussed

179

Electron electric-dipole-moment experiment using a cold cesium fountain  

Science.gov (United States)

Despite its success, the Standard Model of particle physics is incomplete. One of the most sensitive tests of physics beyond the Standard Model is the search for a permanent electric-dipole-moment (EDM) of a fundamental particle such as the electron. This thesis describes a proof-of-principles electron EDM experiment using cold atoms. The experiment has a number of features that distinguish it from other measurement methods: a cold atom fountain replaces, an atomic beam; the magnetic fields are measured and nulled as a function of atomic position; no magnetic fields are used to quantize the atomic state; and the EDM and systematic errors are measured simultaneously by preparing the atoms into a superposition of more than two Zeeman states. The initial EDM results obtained using this apparatus are presented and analyzed with the resulting limit |de| < 2.5 x 10 -22e-cm. Combined with existing technologies, the techniques described in this thesis could make a measurement with a sensitivity that would surpass the current limit on the electron EDM.

Amini, Jason Madjdi

180

Slepton mass matrices, ??e? decay and EDM in SUSY S4 flavor model  

International Nuclear Information System (INIS)

We discuss slepton mass matrices in the S4 flavor model with SUSY SU(5) GUT. By considering the gravity mediation within the framework of supergravity theory, we estimate the SUSY breaking terms in the slepton mass matrices, which contribute to the ??e + ? decay. We obtain a lower bound for the ratio of ??e? as 10-13 if mSUSY and m1/2 are below 500 GeV. The off diagonal terms of slepton mass matrices also contribute to EDM of leptons. The predicted electron EDM is around 10-29-10-28 ecm. Our predictions are expected to be tested in the near future experiments. (author)

181

3D micro-EDM machining technique  

Science.gov (United States)

The micro-EDM machining technique has been broadly applied to fabricate 2D and 3D micro-parts. It is difficult to produce a metal mold with dimension from several micrometers and with the accuracy in the level of micrometers . Poor accuracy comes from electrode wear during 3D micro-EDM machining. In this research, an efficient wear compensation cooperated with CAD/CAM path compensation is provided to improve the machining accuracy. In the experiments, by fabricating a micro-gear and sculpturing letters on surface of tiny steel ball, the technique provided in this research shows the expected results successfully.

Kuo, Chia-Lung; Chen, Shung-Tong; Wu, Ying-Jeng E.; Yen, Albert T.

1997-11-01

182

Search for Excited Electrons in ep Collisions at HERA  

CERN Document Server

A search for excited electrons is performed using the full $e^{\\pm}p$ data sample collected by the H1 experiment at HERA, corresponding to a total luminosity of 475 pb$^{-1}$. The electroweak decays of excited electrons ${e}^{*}\\to{e}{\\gamma}$, ${e}^{*}\\to{e}Z$ and ${e}^{*}{\\to}\

Aaron, F D; Andreev, V; Antunovic, B; Aplin, S; Asmone, A; Astvatsatourov, A; Bacchetta, A; Backovic, S; Baghdasaryan, A; Baranov, P; Barrelet, E; Bartel, Wulfrin; Beckingham, M; Begzsuren, K; Behnke, O; Belousov, A; Berger, N; Bizot, J C; Boenig, M O; Boudry, V; Bozovic-Jelisavcic, I; Bracinik, J; Brandt, G; Brinkmann, M; Brisson, V; Bruncko, D; Bunyatyan, A; Buschhorn, G; Bystritskaya, L; Campbell, A J; Cantun Avila, K B; Cassol-Brunner, F; Cerny, K; Cerny, V; Chekelian, V; Cholewa, A; Contreras, J G; Coughlan, J A; Cozzika, G; Cvach, J; Dainton, J B; Daum, K; Deák, M; De Boer, Y; Delcourt, B; Del Degan, M; Delvax, J; de Roeck, A; De Wolf, E A; Diaconu, C; Dodonov, V; Dossanov, A; Dubak, A; Eckerlin, G; Efremenko, V; Egli, S; Eliseev, A; Elsen, E; Essenov, S; Falkiewicz, A; Faulkner, P J W; Favart, L; Fedotov, A; Felst, R; Feltesse, J; Ferencei, J; Finke, L; Fleischer, M; Fomenko, A; Gabathuler, E; Gayler, J; Ghazaryan, S; Glazov, A; Glushkov, I; Görlich, L; Goettlich, M; Gogitidze, N; Gouzevitch, M; Grab, C; Greenshaw, T; Grell, B R; Grindhammer, G; Habib, S; Haidt, D; Hansson, M; Helebrant, C; Henderson, R C W; Henschel, H; Herrera-Corral, G; Hildebrandt, M; Hiller, K H; Hoffmann, D; Horisberger, R; Hovhannisyan, A; Hreus, T; Jacquet, M; Janssen, M E; Janssen, X; Jemanov, V; Jonsson, L; Johnson, D P; Jung, A W; Jung, H; Kapichine, M; Katzy, J; Kenyon, I R; Kiesling, C; Klein, M; Kleinwort, C; Klimkovich, T; Kluge, T; Knutsson, A; Kogler, R; Korbel, V; Kostka, P; Krämer, M; Krastev, K; Kretzschmar, J; Kropivnitskaya, A; Krüger, K; Kutak, K; Landon, M P J; Lange, W; Lastoviicka-Medin, G; Laycock, P; Lebedev, A; Leibenguth, G; Lendermann, V; Levonian, S; Li, G; Lipka, K; Liptaj, A; List, B; List, J; Loktionova, N; López-Fernandez, R; Lubimov, V; Lucaci-Timoce, A I; Lytkin, L; Makankine, A; Malinovski, E; Marage, P; Marti, L; Martyn, H U; Maxfield, S J; Mehta, A; Meier, K; Meyer, A B; Meyer, H; Meyer, J; Michels, V; Mikocki, S; Milcewicz-Mika, I; Moreau, F; Morozov, A; Morris, J V; Mozer, M U; Mudrinic, M; Müller, K; Murn, P; Nankov, K; Naroska, B; Naumann, T; Newman, P R; Niebuhr, C; Nikiforov, A; Nowak, G; Nowak, K; Nozicka, M; Olivier, B; Olsson, J E; Osman, S; Ozerov, D; Palichik, V; Panagouliasl, I; Pandurovic, M; Papadopouloul, T; Pascaud, C; Patel, G D; Pejchal, O; Peng, H; Pérez, E; Petrukhin, A; Picuric, I; Piec, S; Pitzl, D; Placakyte, R; Polifka, R; Povh, B; Preda, T; Radescu, V; Rahmat, A J; Raicevic, N; Raspiareza, A; Ravdandorj, T; Reimer, P; Rizvi, E; Robmann, P; Roland, B; Roosen, R; Rostovtsev, A; Rotaru, M; Ruiz Tabasco, J E; Rurikova, Z; Rusakov, S; Salek, D; Salvaire, F; Sankey, D P C; Sauter, M; Sauvan, E; Schmidt, S; Schmitt, S; Schmitz, C; Schoeffel, L; Schöning, A; Schultz-Coulon, H C; Sefkow, F; Shaw-West, R N; Shevyakov, I; Shtarkov, L N; Shushkevich, S; Sloan, T; Smiljanic, I; Smirnov, P; Soloviev, Yu; Sopicki, P; South, D; Spaskov, V; Specka, A; Staykova, Z; Steder, M; Stella, B; Straumann, U; Sunar, D; Sykora, T; Tchoulakov, V; Thompson, G; Thompson, P D; Toll, T; Tomasz, F; Tran, T H; Traynor, D; Trinh, T N; Truöl, P; Tsakov, I; Tseepeldorj, B; Tsurin, I; Turnau, J; Tzamariudaki, E; Urban, K; Valkárová, A; Vallée, C; Van Mechelen, P; VargasTrevino, A; Vazdik, Ya; Vinokurova, S; Volchinski, V; Wegener, D; Wessels, M; Wissing, C; Wünsch, E; Yeganov, V; Zácek, J; Zaleisak, J; Zhang, Z; Zhelezov, A; Zhokin, A; Zhu, Y C; Zimmermann, T; Zohrabyan, H; Zomer, F; 10.1016/j.physletb.2008.07.014

2008-01-01

183

Ultrasonic Abrasive Removal Of EDM Recast  

Science.gov (United States)

Ultrasonic abrasive process removes layer of recast material generated during electrical-discharge machining (EDM) of damper pocket on turbine blade. Form-fitted tool vibrated ultrasonically in damper pocket from which material removed. Vibrations activate abrasive in pocket. Amount of material removed controlled precisely.

Mandel, Johnny L.; Jacobson, Marlowe S.

1990-01-01

184

Study of the Diffusion of Carbon, Its Sources, and Effect on Finishing Micro-EDM Performance of Cemented Carbide  

Science.gov (United States)

Apart from the necessity of surface modification based on different applications, in most of the cases, diffusion of carbon or foreign particles on the workpiece surface during micro-electrodischarge machining (micro-EDM) is avoidable, especially in finishing micro-EDM. This study aims to investigate different sources of materials that migrate to the machined surface during fine-finishing of micro-EDM of cemented tungsten carbide (WC-Co). The machined surfaces have been examined under scanning electron microscope and energy dispersive x-ray to investigate the changes in chemical composition. It has been observed that during finishing of micro-EDM, the major source of materials' transfer to both the workpiece and electrode is the diffusion of carbon that comes from the decomposition of the hydrocarbon dielectric. In addition, materials from both workpiece and electrode transfer to each other based on machining conditions and discharge energy. The migration occurs more frequently at lower gap voltages during die-sinking with micro-EDM because of low spark gap and stationary tool electrode. Milling micro-EDM results in lower amount of carbon migration and fewer surface defects that improve the overall surface finish significantly.

Jahan, M. P.; Rahman, M.; Wong, Y. S.

2012-08-01

185

Search for excited electrons using the ZEUS detector  

International Nuclear Information System (INIS)

This paper reports a search for excited electrons at the HERA electron-proton collider. In a sample corresponding to an integrated luminosity of 26 nb-1, no evidence was found for any resonant state decaying into e-?, ?W- or e-Z0. Limits on the coupling strength of an excited electron have been determined for masses between 45 and 225 GeV. This study also reports the observation of the wide-angle e? Compton scattering process. (orig.)

186

Design and Construction of an Electron Electric Dipole Moment Experiment Using Thorium Monoxide  

Science.gov (United States)

Observation of an electron electric dipole moment (eEDM) would imply new sources of CP violation beyond the Standard Model. By measuring spin precession signals on a cryogenic molecular beam, the ACME collaboration is searching for the eEDM in the metastable H ^3?1 state of thorium monoxide. We discuss the design and completed assembly of the first generation of this experiment. Precise electric and magnetic field sources, magnetic shields, and a fluorescence collection system have been constructed and installed, and the molecule beam source has been optimized.ootnotetextN.R. Hutzler et al., Phys. Chem. Chem. Phys., 13, 18976-18985 (2011) With this system we have begun collecting and analyzing eEDM data.

Spaun, Benjamin; Hess, Paul; Hutzler, Nick; Petrik, Elizabeth; Doyle, John; Gabrielse, Gerald; Chan, Cheong; Kirilov, Emil; O'Leary, Brendon; Demille, David

2012-06-01

187

Electron electric-dipole-moment experiment using electric-field quantized slow cesium atoms  

International Nuclear Information System (INIS)

A proof-of-principle electron electric-dipole-moment (e-EDM) experiment using slow cesium atoms, nulled magnetic fields, and electric-field quantization has been performed. With the ambient magnetic fields seen by the atoms reduced to less than 200 pT, an electric field of 6 MV/m lifts the degeneracy between states of unequal |mF| and, along with the low (?3 m/s) velocity, suppresses the systematic effect from the motional magnetic field. The low velocity and small residual magnetic field have made it possible to induce transitions between states and to perform state preparation, analysis, and detection in regions free of applied static magnetic and electric fields. This experiment demonstrates techniques that may be used to improve the e-EDM limit by two orders of magnitude, but it is not in itself a sensitive e-EDM search, mostly due to limitations of the laser system

188

Probing charged matter through h ? ??, gamma ray lines, and EDMs  

Science.gov (United States)

Numerous experiments currently underway offer the potential to indirectly probe new charged particles with masses at the weak scale. For example, the tentative excess in h ? ?? decays and the tentative gamma-ray line in Fermi-LAT data have recently attracted attention as possible one-loop signatures of new charged particles. We explore the interplay between such signals, dark matter direct detection through Higgs exchange, and measurements of the electron EDM, by studying the size of these effects in several models. We compute one-loop effects to explore the relationship among couplings probed by different experiments. In particular, models in which dark matter and the Higgs both interact with charged particles at a detectable level typically induce, at loop level, couplings between dark matter and the Higgs that are around the level of current direct detection sensitivity. Intriguingly, one-loop h ? ?? and DM DM ? ??, two-loop EDMs, and loop-induced direct detection rates are all coming within range of existing experiments for approximately the same range of charged particle masses, offering the prospect of an exciting coincidence of signals at collider, astrophysical, underground and atomic physics measurements.

Fan, JiJi; Reece, Matthew

2013-06-01

189

The neutron EDM experiment at the ILL  

International Nuclear Information System (INIS)

The latest-generation neutron electric dipole moment (EDM) experiment has been collecting data at the ILL since 1996. It uses a 'cohabiting' atomic-mercury magnetometer to measure and compensate for the magnetic field fluctuations that were the principal source of systematic errors in previous experiments. The first results, which are soon to be published, essentially verify the existing limit on the dipole moment dn; however, this new measurement is clearly limited by statistical rather than systematic uncertainties

190

Search for excited electrons in ep collisions at HERA  

International Nuclear Information System (INIS)

A search for excited electrons is performed using the full e±p data sample collected by the H1 experiment at HERA, corresponding to a total luminosity of 475 pb-1. The electroweak decays of excited electrons e* ?e?, e* ?eZ and e* ??W with subsequent hadronic or leptonic decays of the W and Z bosons are considered. No evidence for excited electron production is found. Mass dependent exclusion limits on e* production cross sections and on the ratio f/? of the coupling to the compositeness scale are derived within gauge mediated models. These limits extend the excluded region compared to previous excited electron searches. The e* production via contact interactions is also addressed for the first time in ep collisions. (orig.)

191

Search for Electron Neutrino Appearance in MINOS  

Energy Technology Data Exchange (ETDEWEB)

The MINOS Collaboration continues its search for {nu}{sub e} appearance in the NuMI (Neutrinos at the Main Injector) beam at Fermilab. Neutrinos in the beam interact in the Near Detector, located 1 km from the beam source, allowing us to characterize the backgrounds present in our analysis. In particular, we can estimate the number of {nu}{sub e} candidate events we expect to see in the Far Detector (735 km away, in the Soudan mine in northern Minnesota) in the presence or absence of {nu}{sub {mu}} {yields} {nu}{sub e} oscillation. Recent efforts to improve the sensitivity of the analysis, including upgrades to the event identification algorithm and fitting procedure, are discussed, and the latest results from the search are presented.

Orchanian, Mhair; /Caltech

2011-09-01

192

AN IMPROVED TOPOLOGICAL DESCRIPTOR EDm AND ITS APPLICATION  

OpenAIRE

In this paper, on the basis of the topological index EDm derived from ionicity index matrix, improved distance matrix and branching degree matrix, we proposed the new topological descriptor EDm' by introducing the bond angle into hidden hydrogen graph of molecules and using the geometric distance instead of the sum of bond length between two vertexes. The EDm describes the molecular structure more accurately, and realizes unique characterization to cis-trans isomers. The quantitative structur...

CHANGMING NIE; YAXIN WU; RONGYAN WU; SONGNIAN WEN

2012-01-01

193

Search for scalar electrons at PEP  

International Nuclear Information System (INIS)

Experimental results from e+e- reactions at the Positron Electron Project (PEP) using the High Resolution Spectrometer (HRS) are presented. Events with two electrons, and no other charged particles, in the final state are studied. Limits are given for the production of scalar-electrons predicted by models based on supersymmetry. In particular the pair production of such particles through s-channel single photon annihilation and t-channel inelastic scattering is considered. The data are well described by quantum electrodynamics (QED) but we observe one event which is also consistent with a supersymmetric model. Using this single event we find that the mass, M/sub se/, of these scalar-electrons es excluded, to 95% CL, in the range 1.8 less than or equal to M/sub se/ less than or equal to 14.2 GeV/c2. A description of the HRS detector is given with particular emphasis on the electronic trigger system

194

Search for muon to electron neutrino oscillations  

International Nuclear Information System (INIS)

A search for ?? ? ?e and anti ?? ? anti ?e oscillations has been carried out with the CHARM II detector exposed to the CERN wide band neutrino beam. The data were collected over five years, alternating beams mainly composed of muon-neutrinos and muon-antineutrinos. The number of interactions of ?e and anti ?e observed is comparable with the number of events expected from flux calculations. For large squared mass differences the upper limits obtained on the mixing angle are sin22? -3 for ?? oscillating to ?e and sin22? -3 for anti ?? to anti ?e, at the 90% confidence level. Combining neutrino and antineutrino data the upper limit is 5.6 . 10-3. (orig.)

195

Optimization of EDM Process of (Cu-W EDM Electrodes on Different Progression  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of this research work is to determine the optimal cutting condition of EDM process of different work piece materials using different compositions of Cu-W tool Electrodes. The key cutting factors such as Discharge Current, Voltage, Pulse- On – Time, Duty Cycle, Spark Gap and flushing pressure will be optimized.

Arvind Kumar Tiwari

2014-11-01

196

An alternative search for the electron capture of 123Te  

International Nuclear Information System (INIS)

A search for the second forbidden electron capture of 123Te has been performed. A new technique for searches of rare nuclear decays using CdZnTe detectors has been established. After a measuring time of 195 h no signal could be found resulting in a lower half-life limit of T1/2 > 3.2 x 1016 years (95% CL) for this process. This clearly discriminates between existing experimental results which differ by six orders of magnitude, and our data are in strong favour of the result with longer half-lives. (brief report)

197

A search for supersymmetric electrons with the Mark II detector at PEP [Positron Electron Project  

International Nuclear Information System (INIS)

An experimental search for selectrons, the supersymmetric partner of the electron, has been performed at the PEP storage ring at SLAC using the Mark II detector. The experimental search done was based upon hypothetical reaction in e+e- interactions at PEP center of mass energies of 29 GeV. In this reaction the selectrons, e, are assumed produced by the interaction of one of initial state electrons with a photon radiated from the other initial state electron. This latter electron is assumed to continue down the beam pipe undetected. The photon and electron then produce a selectron and a photino, ?, in the supersymmetric analog of Compton scattering. The photino is assumed to be the lightest supersymmetric particle, and as such, does not interact in the detector, thereby escaping detection very much like a neutrino. The selectron is assumed to immediately decay into an electron and photino. This electron is produced with large p perpendicular with respect to the beam pipe, since it must balance the transverse momentum carried off by the photinos. Thus, the experimental signature of the process is a single electron in the detector with a large unbalanced tranverse momentum. No events of this type were observed in the original search of 123 pb-1 of data, resulting in a cross section limit of less than 2.4 x 10-2 pb (at the 95% CL) within the detector acceptance. This cross section upper limit applies to any process which produces anomalous single electron events with missing transverse momentum. When interpreted as a supersymmetry search it results in a lower selectron mass limit of 22.2 GeV/c2 for the case of massless photinos. Limits for non-zero mass photinos have been calculated. 87 refs., 67 figs., 17 tabs

198

A search for supersymmetric electrons with the Mark II detector at PEP (Positron Electron Project)  

Energy Technology Data Exchange (ETDEWEB)

An experimental search for selectrons, the supersymmetric partner of the electron, has been performed at the PEP storage ring at SLAC using the Mark II detector. The experimental search done was based upon hypothetical reaction in e/sup +/e/sup -/ interactions at PEP center of mass energies of 29 GeV. In this reaction the selectrons, e-tilde, are assumed produced by the interaction of one of initial state electrons with a photon radiated from the other initial state electron. This latter electron is assumed to continue down the beam pipe undetected. The photon and electron then produce a selectron and a photino, ..gamma..-tilde, in the supersymmetric analog of Compton scattering. The photino is assumed to be the lightest supersymmetric particle, and as such, does not interact in the detector, thereby escaping detection very much like a neutrino. The selectron is assumed to immediately decay into an electron and photino. This electron is produced with large p perpendicular with respect to the beam pipe, since it must balance the transverse momentum carried off by the photinos. Thus, the experimental signature of the process is a single electron in the detector with a large unbalanced tranverse momentum. No events of this type were observed in the original search of 123 pb/sup -1/ of data, resulting in a cross section limit of less than 2.4 x 10/sup -2/ pb (at the 95% CL) within the detector acceptance. This cross section upper limit applies to any process which produces anomalous single electron events with missing transverse momentum. When interpreted as a supersymmetry search it results in a lower selectron mass limit of 22.2 GeV/c/sup 2/ for the case of massless photinos. Limits for non-zero mass photinos have been calculated. 87 refs., 67 figs., 17 tabs.

LeClaire, B.W.

1987-10-01

199

Development of the Measurement System for the Search of an Electric Dipole Moment of the Electron with Laser-Cooled Francium Atoms  

OpenAIRE

We plan to measure the permanent electric dipole moment (EDM) of the electron, which has the sensitivity to the CP violation in theories beyond the standard model by using the laser-cooled francium (Fr) atom. This paper reports the present status of the EDM measurement system. A high voltage application system was constructed in order to produce the strong electric field (100 kV/cm) needed for the experiment. After conditioning, the leakage current was 10 pA when a high voltage of 43 kV was a...

Inoue T; Ando S.; Arikawa H.; Ezure S.; Harada K.; Hayamizu T.; Ishikawa T; Itoh M; Kato K.; Kato T; Kawamura H.; Nataraj H.S.; Sato T.; Uchiyama A.; Aoki T

2014-01-01

200

Development of the Measurement System for the Search of an Electric Dipole Moment of the Electron with Laser-Cooled Francium Atoms  

Science.gov (United States)

We plan to measure the permanent electric dipole moment (EDM) of the electron, which has the sensitivity to the CP violation in theories beyond the standard model by using the laser-cooled francium (Fr) atom. This paper reports the present status of the EDM measurement system. A high voltage application system was constructed in order to produce the strong electric field (100 kV/cm) needed for the experiment. After conditioning, the leakage current was 10 pA when a high voltage of 43 kV was applied. Also, a drift of an environmental field was measured at the planned location of the Fr-EDM experiment. The drift is suppressed at present down to the level of 10 pT by installing a 4-layermagnetic shield. Improvements are still needed to reach the required field stability of 1 fT.

Inoue, T.; Ando, S.; Aoki, T.; Arikawa, H.; Ezure, S.; Harada, K.; Hayamizu, T.; Ishikawa, T.; Itoh, M.; Kato, K.; Kato, T.; Kawamura, H.; Nataraj, H. S.; Sato, T.; Uchiyama, A.; Aoki, T.; Furukawa, T.; Hatakeyama, A.; Hatanaka, K.; Imai, K.; Murakami, T.; Shimizu, Y.; Wakasa, T.; Yoshida, H. P.; Sakemi, Y.

2014-03-01

201

Development of the Measurement System for the Search of an Electric Dipole Moment of the Electron with Laser-Cooled Francium Atoms  

Directory of Open Access Journals (Sweden)

Full Text Available We plan to measure the permanent electric dipole moment (EDM of the electron, which has the sensitivity to the CP violation in theories beyond the standard model by using the laser-cooled francium (Fr atom. This paper reports the present status of the EDM measurement system. A high voltage application system was constructed in order to produce the strong electric field (100 kV/cm needed for the experiment. After conditioning, the leakage current was 10 pA when a high voltage of 43 kV was applied. Also, a drift of an environmental field was measured at the planned location of the Fr-EDM experiment. The drift is suppressed at present down to the level of 10 pT by installing a 4-layermagnetic shield. Improvements are still needed to reach the required field stability of 1 fT.

Inoue T.

2014-03-01

202

Towards Semantic Search and Inference in Electronic Medical Records  

Directory of Open Access Journals (Sweden)

Full Text Available Background This paper presents a novel approach to searching electronic medical records that is based on concept matching rather than keyword matching. Aims The concept-based approach is intended to overcome specific challenges we identified in searching medical records. Method Queries and documents were transformed from their term-based originals into medical concepts as defined by the SNOMED-CT ontology. Results Evaluation on a real-world collection of medical records showed our concept-based approach outperformed a keyword baseline by 25% in Mean Average Precision. Conclusion The concept-based approach provides a framework for further development of inference based search systems for dealing with medical data.

Bevan Koopman

2012-09-01

203

Clarification of EDM Phenomena by Spectroscopic Analysis  

Science.gov (United States)

In electrical discharge machining (EDM), workpiece is machined using heat of the arc-plasma generated in the discharge gap after dielectric breakdown. The characteristics and behavior of the arc-plasma during a single discharge have a great influence on the formation of the discharge crater. In order to improve the machining accuracy and surface roughness of the workpiece, it is quite necessary to research on plasma behavior and its characteristics. In this study, light intensities radiated from the plasma which are considered to reflect the material removal behavior were measured using a spectrometer under different machining conditions. It was found that the starting moment when light intensity was detected had a time delay after the dielectric breakdown. It is because of the time needed for the material to be evaporated before its temperature reaches the boiling point. Besides, the time delay increases accordingly by slowing down the rise speed of the discharge current because of lower heat flux flowing into the surface of the workpiece. In addition, heat conduction analysis was conducted to compare the time delay calculated with the experimental ones. It was found that plasma expanded in a rapid speed within about 180ns right after dielectric breakdown and remained constant with the diameter of about 20µm after that under a roughing condition of micro EDM.

Qu, Chao; Natsu, Wataru; Kunieda, Masanori

204

Electrical measurements in µ-EDM  

International Nuclear Information System (INIS)

The phenomena occurring between the electrodes in electric discharge machining when manufacturing features on the micro-metre scale (µ-EDM) is not fully understood. Poor quantitative knowledge of the sources of variability affecting this process hinders the identification of its natural tolerance limits. Moreover, improvements in measuring systems contribute to the acquisition of new information that often conflicts with existent theoretical models of this process. The prime objective of this paper is to advance the experimental knowledge of µ-EDM by providing a measurement framework for the electrical discharges. The effects of the electrodes metallic materials (Ag, Ni, Ti, W) on the electrical measurements defined in the proposed framework are analysed. Linear mixed-effects models are fitted to the experimental data using the restricted maximum likelihood method (REML). The main conclusion drawn is that the discharge current and voltage as defined and measured in this framework do significantly depend on the electrode material even when keeping all the other machining conditions unchanged

205

New bounds on the electric dipole moment of the electron and on T-odd electron-nucleon coupling  

International Nuclear Information System (INIS)

The electric dipole moment (EDM) of the electron, together with the hyperfine coupling, induces an EDM in atoms and molecules with closed electron shells. Experiments with 129Xe and TIF have yielded bounds on the EDM of the electron (d/Vertical BareVertical Bar = (0.4 +- 1.4) x 10-23 cm; (0.9 +- 1.3) x 10-23 cm) and on the T-odd scalar electron-nucleon coupling constant

206

Slepton Mass Matrices, mu -> e gamma Decay and EDM in SUSY S4 Flavor Model  

CERN Document Server

We discuss slepton mass matrices in the $S_4$ flavor model with SUSY $SU(5)$ GUT. By considering the gravity mediation within the framework of supergravity theory, we estimate the SUSY breaking terms in the slepton mass matrices, which contribute to the $\\mu \\rightarrow e + \\gamma$ decay. We obtain a lower bound for the ratio of $\\mu\\rightarrow e\\gamma$ as $10^{-13}$ if $m_{\\text{SUSY}}$ and $m_{1/2}$ are below $500$GeV. The off diagonal terms of slepton mass matrices also contribute to EDM of leptons. The predicted electron EDM is around $10^{-29}-10^{-28}$cm. Our predictions are expected to be tested in the near future experiment.

Ishimori, Hajime

2010-01-01

207

The neutron EDM in the SM: a review  

International Nuclear Information System (INIS)

We review the status of the electric dipole moment (EDM) of neutron in the Standard Model (SM). The contributions of the strong and electroweak interactions are discussed separately. In each case the structure of Lagrangian and the sources of CP violation are specified, and subsequently calculational details are given. These two contributions to the neutron EDM exist in any extension of the SM including supersymmetry, two-doublet models as well as models with more than three generations of fermions. We briefly discuss the status of the neutron EDM in such extensions and give the relevant literature. (author)

208

Broadband velocity modulation spectroscopy of HfF^+: towards a measurement of the electron electric dipole moment  

OpenAIRE

Precision spectroscopy of trapped HfF^+ will be used in a search for the permanent electric dipole moment of the electron (eEDM). While this dipole moment has yet to be observed, various extensions to the standard model of particle physics (such as supersymmetry) predict values that are close to the current limit. We present extensive survey spectroscopy of 19 bands covering nearly 5000 cm^(-1) using both frequency-comb and single-frequency laser velocity-modulation spectros...

Cossel, Kevin C.; Gresh, Daniel N.; Sinclair, Laura C.; Coffey, Tyler; Skripnikov, Leonid V.; Petrov, Alexander N.; Mosyagin, Nikolai S.; Titov, Anatoly V.; Field, Robert W.; Meyer, Edmund R.; Cornell, Eric A.; Ye, Jun

2012-01-01

209

Micro-Hole Multi-Point Punching System Using Punch and Die Made by EDM  

Science.gov (United States)

In this research a multi-point micro punch and die system was developed. The process of electric discharge machining (EDM) was used to produce both the punch and die. The punches were machined from a 5 mm diameter tungsten and a 10 mm diameter tool steel round rods by wire electric discharge machining (WEDM), using a 200 µm diameter wire electrode. The die holes were made using the punch as the electrode. The EDM process of the holes was carried out on a newly developed desktop EDM machine. The punch and die placed on a micro-die set and then on a micro press were used to produce micro-holes using an automatic control system developed for this process. Experiments to produce 50 µm to 67 µm square micro-holes on 50 µm thick aluminum, 30 µm thick copper and 20 µm thick stainless steel foils were conducted. The capabilities of multi-point punching using the tungsten punch and a tool steel punch were examined and tungsten was chosen as the material of choice for making the punch tool. A scanning electron microscope confirmed that the holes produced are clean, and the sheared surfaces smooth. The punch tool showed no signs of deformation or cracks even after repeated punching.

Broomfield, Mark; Mori, Toshihiko; Mikuriya, Teruaki; Tachibana, Kazushi

210

Performance Evaluation of Rotary EDM by Experimental design Technique  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents an experimental design to study the performance of rotary electro-discharge machining (EDM. Scientific investigations have been carried out to find the effect of various EDM parameters. Titanimn alloy and die steel workpieces were machined with copper-tungsten tool electrode. The response surface technique has been adopted to compare the performance of rotary EDM, since such technological surfaces serve as an objective criteria to compare EDM systems. Moreover, such a surface and its response function serve as a mathematical model of the process. The analysis of the results was based on standard statistical techniques. The response surfaces and the corresponding response functions were determined for the machining indices for metal removal rate, surface finish, micro-hardness, etc. All the calculations were carried out through a computer programme specially developed for this purpose."

J.S. Joshi

2013-04-01

211

EDM drilling of high aspect ratio micro holes  

OpenAIRE

The increasing demand for mechanical micro components has enhanced the development of numerous production technologies, like micro-EDM. Micro-EDM is able to guarantee the latest market requirements both in terms of miniaturization capabilities and quality of the features obtained. With this production technique it is possible to fabricate several types of features such as, small 3D milled features and HAR (High Aspect Ratio) micro holes. One of the main concerns in micro machining, and most o...

D Urso, Gianluca Danilo; Merla, Cristina; Maccarini, Giancarlo

2013-01-01

212

Using a helical micro-tool in micro-EDM combined with ultrasonic vibration for micro-hole machining  

Science.gov (United States)

This paper presents a novel process using micro-electro-discharge- machining (micro-EDM) combined with ultrasonic vibration by a helical micro-tool electrode to drill and finish micro-holes. During the machining processes, a micro-tool is directly fabricated by wire electro-discharge grinding (WEDG) using micro-EDM combined with various methods for machining the micro-hole and by ultrasonic vibration to finish the hole wall. In this work, circular micro-holes are machined in a high nickel alloy by cylindrical and helical electrodes. Using a helical micro-tool electrode for micro-EDM combined with ultrasonic vibration (HE-MEDM-UV) can substantially reduce the EDM gap, taper and machining time for deep micro-hole drilling. In addition, using a helical micro-tool with micro ultrasonic vibration finishing (HE-MUVF), good surface quality and less taper of the hole wall can be obtained by applying a suitable electrode step variation, rotational speed and ultrasonic amplitude with a machining time of approximately 25 min. According to scanning electron microscopy (SEM) micrographs and atomic force microscopy (AFM) measurement, HE-MUVF can indeed improve the surface roughness from 1.345 µm Rmax before finishing to 0.58 µm Rmax after HE-MUVF. This result demonstrates that using HE-MEDM-UV combined with MUVF can yield micro-holes of precise shape and smooth surface.

Hung, Jung-Chou; Lin, Jui-Kuan; Yan, Biing-Hwa; Liu, Hung-Sung; Ho, Ping-Hsing

2006-12-01

213

Theoretical study of thorium monoxide for the electron electric dipole moment search, II: Electronic properties of $H^3\\Delta_1$ in ThO  

CERN Document Server

Recently an improved limits on the electron electric dipole moment, \\eEDM, and dimensionless constant, $k_{T,P}$, characterizing the strength of the T,P-odd pseudoscalar$-$scalar electron$-$nucleus neutral current interaction in the $H^3\\Delta_1$ state of ThO molecule were obtained by ACME collaboration [Science 343, 269 (2014)]. The interpretation of the experiment in terms of fundamental quantities \\eEDM\\ and $k_{T,P}$ is based on the results of theoretical study of appropriate ThO characteristics, the effective electric field acting on electron, \\Eeff, and a parameter of the T,P-odd pseudoscalar$-$scalar interaction, $W_{T,P}$, given in [J.Chem.Phys.\\ 139, 221103 (2013)] by St.Petersburg group. To reduce the uncertainties of the given limits we report improved calculations of the molecular state$-$specific quantities \\Eeff, 81.5~GV/cm, and $W_{T,P}$, 112~kHz, with the uncertainty within 7\\% of the magnitudes. Thus, the values recommended to use for the upper limits of the quantities are 75.8~GV/cm and 104~...

Skripnikov, L V

2014-01-01

214

A New Limit on the Electron Electric Dipole Moment: Beam Production, Data Interpretation, and Systematics  

Science.gov (United States)

The charge distribution associated with an electron has surprising implications for a number of outstanding mysteries in physics. Why is the universe made out of matter versus anti-matter, instead of both equally? What new particles and interactions lie beyond the current reach of accelerators like the LHC? Models which propose answers to these questions, such as Supersymmetry, tend to predict a small, yet potentially measurable, asymmetric interaction between an electron and an electric field, characterized by an electric dipole moment (EDM). Despite over six decades of experimental searching, no EDM of any fundamental particle has ever been measured; however, these experiments continue to provide some of the most stringent limits on new physics. Here, we present the results of a new search for the electron EDM, de = (-2.1 +/- 3.7stat +/- 2.5syst) x 10-29 e cm, which represents an order of magnitude improvement in sensitivity from the previous best limit. Since our measurement is consistent with zero, we present the upper limit of |de| < 8.7 x 10-29 e cm with 90 percent confidence.

Hutzler, Nicholas Richard

215

Machining of Cemented Tungsten Carbide using EDM  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, we investigate the possibility of machining cemented tungsten carbide WC+6% Co by using copper. Tungsten carbide is hard and brittle with low thermal conductivity and low thermal expansion. The high resistant to abrasive wear and high melting point are the main reason for the selection of these materials for large number of applications such as machining tool and die material. The hardness of WC+Co primarily depends on the average grain size and cobalt content. The difficulty when machining cemented tungsten carbide comes from the thermal stress. The micro cracks enlarge, which leads to macro crack and fragmentation. This can be referred to the low thermal expansion, thermal conductivity and brittleness, which create a high thermal stress. Generally, cooling and removal of the cracked particles are difficult. In order to develop the optimal machining process for the desirable machining response, L9 Taguchi Orthogonal Array (OA were used. This orthogonal array is used for optimization of the following variables; Peak-Current (IP, pulse ON-Time (ON, pulse OFF-Time (OFF and Gap-Voltage (GAP. The results show that it’s possible to EDMing WC-Co using copper electrode at very low energy setting but at the expense of material removal rate MRR.

A.M.A. Rani

2011-01-01

216

Search for Muon to Electron Conversion at J-PARC  

International Nuclear Information System (INIS)

We would like to present the status of the COMET experiment, which aims at searching for muon to electron conversion in a muonic atom at J-PARC with an experimental sensitivity of better than 10-16. The muon to electron conversion is one of the processes of charged lepton flavor violation (cLFV). Physics of cLFV has attracted much attention from theorists and experimentalists since cLFV would have a potential to find a clue of physics beyond the Standard Model. In particular, muon to electron conversion in a muonic atom has been identified as a next-generation process to improve a sensitivity beyond the MEG at PSI. The aimed sensitivity with the COMET is a factor of 10,000 better than the present experimental limits. The COMET proposal has been approved at the stage-1 level at J-PARC, Japan in 2009, and the detailed design works and R are being undertaken. In addition, R for the subsequent project called the PRISM/PRIME with an experimental sensitivity of better than 10-18 has started in the international framework. In this paper, we would like to present physics motivation and report all the experimental status on the COMET. (author)

217

LIPSS Free-Electron Laser Searches for Dark Matter  

Energy Technology Data Exchange (ETDEWEB)

A variety of Dark Matter particle candidates have been hypothesized by physics Beyond the Standard Model (BSM) in the very light (10{sup -6} - 10{sup -3} eV) range. In the past decade several international groups have conducted laboratory experiments designed to either produce such particles or extend the boundaries in parameter space. The LIght Pseudo-scalar and Scalar Search (LIPSS) Collaboration, using the 'Light Shining through a Wall' (LSW) technique, passes the high average power photon beam from Jefferson Lab's Free-Electron Laser through a magnetic field upstream from a mirror and optical beam dump. Light Neutral Bosons (LNBs), generated by coupling of photons with the magnetic field, pass through the mirror ('the Wall') into an identical magnetic field where they revert to detectable photons by the same coupling process. While no evidence of LNBs was evident, new scalar coupling boundaries were established. New constraints were also determined for hypothetical para-photons and for millicharged fermions. We will describe our experimental setup and results for LNBs, para-photons, and milli-charged fermions. Plans for chameleon particle searches are underway.

Afanaciev, Andrei; Beard, Kevin; Biallas, George; Boyce, James R; Minarni, M; Ramdon, R; Robinson, Taylor; Shinn, Michelle D

2011-09-01

218

LIPSS Free-Electron Laser Searches for Dark Matter  

International Nuclear Information System (INIS)

A variety of Dark Matter particle candidates have been hypothesized by physics Beyond the Standard Model (BSM) in the very light (10-6 - 10-3 eV) range. In the past decade several international groups have conducted laboratory experiments designed to either produce such particles or extend the boundaries in parameter space. The LIght Pseudo-scalar and Scalar Search (LIPSS) Collaboration, using the 'Light Shining through a Wall' (LSW) technique, passes the high average power photon beam from Jefferson Lab's Free-Electron Laser through a magnetic field upstream from a mirror and optical beam dump. Light Neutral Bosons (LNBs), generated by coupling of photons with the magnetic field, pass through the mirror ('the Wall') into an identical magnetic field where they revert to detectable photons by the same coupling process. While no evidence of LNBs was evident, new scalar coupling boundaries were established. New constraints were also determined for hypothetical para-photons and for millicharged fermions. We will describe our experimental setup and results for LNBs, para-photons, and milli-charged fermions. Plans for chameleon particle searches are underway.

219

Neutrino-electron scattering and the search for new physics  

International Nuclear Information System (INIS)

I want to discuss the role of neutrino-electron scattering in the search for physics beyond the standard model. The standard model makes specific predictions about the nature of the neutrinos which participate in such processes and about the interactions responsible for them. The process upon which I shall concentrate is elastic scattering, but I shall pay some attention to inelastic processes in which the target electron is itself transformed into a heavier charged lepton, in other words the inverse of the decay of the heavier lepton. In the case of elastic scattering we are mainly looking at neutral-currents and we can ask a series of simple questions: Does the interaction conserve lepton flavor? Does it fit the prescriptions of the standard model? Are the neutrinos Majorana or Dirac particles? In the case of inverse muon and tau decays we are looking at charge-currents, and we want to pin down the identity of the neutrinos emitted in the decay of these charged leptons as well as to set bounds on non-(V-A) components of the interaction. In order to discuss these topics, it is useful to review the general properties of the scattering process, especially the kinematics and the general form of the differential cross-section. Kinematics are important because they prevent us from searching for some processes and effects which we would like to detect. The differential cross-section, if measured with sufficient care, may tell us something about the presence of non-standard terms in the interaction and even about the nature of the neutrino. The detailed outline of the talk is: identity of the final state neutrino; kinematics; differential cross-sections; oscillations and universality; a test for Dirac neutrinos; inverse muon decay; and the standard model and radiative corrections. 22 ref., 2 tabs

220

AN IMPROVED TOPOLOGICAL DESCRIPTOR EDm AND ITS APPLICATION  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, on the basis of the topological index EDm derived from ionicity index matrix, improved distance matrix and branching degree matrix, we proposed the new topological descriptor EDm' by introducing the bond angle into hidden hydrogen graph of molecules and using the geometric distance instead of the sum of bond length between two vertexes. The EDm describes the molecular structure more accurately, and realizes unique characterization to cis-trans isomers. The quantitative structure-property relationship (QSPR models, with correlation coefficients (R in the range of 0.984-1.000 for the boiling point (b.p., the standard enthalpy of formation ( DfHm?, the molar refraction (Rm and the molar volume (Vm of some cis-trans isomers for alkenes, are subsequently developed by index EDm'. Moreover, the good stability and predictive ability of the models were demonstrated by LOO (leave-one-out method and RSP (random sampling prediction method, which further manifests the index EDm has high potential of wide applications in QSPR study.

CHANGMING NIE

2012-03-01

221

Hybrid micromachining using a nanosecond pulsed laser and micro EDM  

International Nuclear Information System (INIS)

Micro electrical discharge machining (micro EDM) is a well-known precise machining process that achieves micro structures of excellent quality for any conductive material. However, the slow machining speed and high tool wear are main drawbacks of this process. Though the use of deionized water instead of kerosene as a dielectric fluid can reduce the tool wear and increase the machine speed, the material removal rate (MRR) is still low. In contrast, laser ablation using a nanosecond pulsed laser is a fast and non-wear machining process but achieves micro figures of rather low quality. Therefore, the integration of these two processes can overcome the respective disadvantages. This paper reports a hybrid process of a nanosecond pulsed laser and micro EDM for micromachining. A novel hybrid micromachining system that combines the two discrete machining processes is introduced. Then, the feasibility and characteristics of the hybrid machining process are investigated compared to conventional EDM and laser ablation. It is verified experimentally that the machining time can be effectively reduced in both EDM drilling and milling by rapid laser pre-machining prior to micro EDM. Finally, some examples of complicated 3D micro structures fabricated by the hybrid process are shown

222

AN IMPROVED TOPOLOGICAL DESCRIPTOR EDm AND ITS APPLICATION  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english In this paper, on the basis of the topological index EDm derived from ionicity index matrix, improved distance matrix and branching degree matrix, we proposed the new topological descriptor EDm' by introducing the bond angle into hidden hydrogen graph of molecules and using the geometric distance in [...] stead of the sum of bond length between two vertexes. The EDm describes the molecular structure more accurately, and realizes unique characterization to cis-trans isomers. The quantitative structure-property relationship (QSPR) models, with correlation coefficients (R) in the range of 0.984-1.000 for the boiling point (b.p.), the standard enthalpy of formation ( DfHm?), the molar refraction (Rm) and the molar volume (Vm) of some cis-trans isomers for alkenes, are subsequently developed by index EDm'. Moreover, the good stability and predictive ability of the models were demonstrated by LOO (leave-one-out) method and RSP (random sampling prediction) method, which further manifests the index EDm has high potential of wide applications in QSPR study.

CHANGMING, NIE; YAXIN, WU; RONGYAN, WU; SONGNIAN, WEN.

2012-03-01

223

Effect of electro discharge machining (EDM) on the AISI316L SS white layer microstructure and corrosion resistance  

OpenAIRE

The localised corrosion resistance of austenitic stainless steels is strongly influenced by the quality of finished surface. EDM machining induces substantial changes by the high thermal gradients generated by electric sparks. Experimental techniques such as roughness measurement, scanning electron microscopy (SEM), energy dispersive microanalysis (EDX) and X-ray diffraction technique, reveal microgeometrical, microstructural, chemical and mechanical changes. These changes lead to white and h...

Sidhom, Habib; Ghanem, Farhat; Amadou, Tidiane; Gonzalez, Gonzalo; Braham, Chedly

2013-01-01

224

The effect of microstructure on fatigue performance of Ti-6Al-4V alloy after EDM surface treatment for application in orthopaedics.  

Science.gov (United States)

Three different microstructures--equiaxed, bi-modal and coarse lamellar--are prepared from Ti-6Al-4V alloy. Electric discharge machining (EDM) with a high peak current (29 A) is performed in order to impose surface roughness and modify the chemical composition of the surface. Detailed scanning electron microscopy (SEM) investigation revealed a martensitic surface layer and subsurface heat affected zone (HAZ). EDX measurements showed carbon enriched remnants of the EDM process on the material surface. Rotating bending fatigue tests are undertaken for EDM processed samples for all three microstructures and also for electropolished-benchmark-samples. The fatigue performance is found to be rather poor and not particularly dependent on microstructure. The bi-modal microstructure shows a slightly superior high cycle fatigue performance. This performance can be further improved by a suitable heat treatment to an endurance limit of 200 MPa. PMID:22098894

Stráský, Josef; Jane?ek, Miloš; Harcuba, Petr; Bukovina, Michal; Wagner, Lothar

2011-11-01

225

A search for single electron production in electron positron annihilation at E = 29 GeV  

International Nuclear Information System (INIS)

This thesis presents experimental results from the ASP detector which took data on e+e- interactions in the PEP storage ring at SLAC. Its design was particularly suitable for searching for production of supersymmetric particles. The motivations for and phenomenology of Supersymmetry are discussed. In particular, the production of a single supersymmetric electron (''selectron'', e) in combination with a supersymmetric photon (''photino'', ?) would result in events in which a single electron and no other particles are observed in the detector at an e+e- collider such as PEP, provided the masses of these particles are not too large. Such events would also result from the production of a single supersymmetric W-boson (''wino'', W) in combination with a supersymmetric neutrino (''sneutrino'', ?). These processes make it possible to search for electrons and winos with masses greater than the beam energy. Observation of these unusual events would distinctly indicate the production of new particles. The ASP detector was designed to be hermetic and to provide efficient event reconstruction for low multiplicity events. The detector is described and its performance is evaluated; it is found to be well-suited to this study. The data sample collected with the detector was thoroughly analyzed for evidence of single-electron events. The various possible background processes are considered and Monte Carlo calculations of the distributions from single selectron and single wino production are presented. Using this information an efficient off-line event selection process was developed, and it is described in detail. 82 refs., 41 figs., 4 tabs

226

The study of lepton EDM in CP violating BLMSSM  

CERN Document Server

In the supersymmetric model with local gauged baryon and lepton numbers(BLMSSM), the CP-violating effects are considered to study the lepton electric dipole moment(EDM). The CP-violating phases in BLMSSM are more than those in the standard model(SM) and can give large contributions. The analysis of the EDMs for the leptons $e,\\mu, \\tau$ is shown in this work. It is in favour of exploring the source of CP violating and probing the physics beyond SM.

Zhao, Shu-Min; Zhan, Xi-Jie; Zhang, Hai-Bin; Yan, Ben

2014-01-01

227

Modeling of wire-cut EDM by neural network  

Science.gov (United States)

Wire-cut EDM is a highly complex process, which is characterized by non-linear behavior. Due to very large number of input parameters, a Neural Network Approach is followed in this paper to model this process. A large number of experiments have been carried out to train the network. The model is also tested using additional experimental data. It is found that neural network models of wire-cut EDM process provide results with required accuracy. The important input parameters have been identified and reported in this paper.

Shunmugam, M. S.; Kumar, S. S.; Kaul, I. K.

1999-08-01

228

Enhancement of the electron electric dipole moment in gadolinium garnets  

International Nuclear Information System (INIS)

Effects caused by the electron electric dipole moment (EDM) in gadolinium garnets are considered. Experimental studies of these effects could improve the current upper limit on the electron EDM by several orders of magnitude. We suggest a consistent theoretical model and perform calculations of observable effects in gadolinium gallium garnet and gadolinium iron garnet. Our calculation accounts for both direct and exchange diagrams

229

Enhancement of the electron electric dipole moment in gadolinium garnets  

CERN Document Server

Effects caused by the electron electric dipole moment (EDM) in gadolinium garnets are considered. Experimental studies of these effects could improve current upper limit on the electron EDM by several orders of magnitude. We suggest a consistent theoretical model and perform calculations of observable effects in gadolinium gallium garnet and gadolinium iron garnet. Our calculation accounts for both direct and exchange diagrams.

Mukhamedjanov, T N; Sushkov, O P

2003-01-01

230

Electron electric dipole moment experiment using electric-fieldquantized slow cesium atoms  

Energy Technology Data Exchange (ETDEWEB)

A proof-of-principle electron electric dipole moment (e-EDM)experiment using slow cesium atoms, nulled magnetic fields, and electricfield quantization has been performed. With the ambient magnetic fieldsseen by the atoms reduced to less than 200 pT, an electric field of 6MV/m lifts the degeneracy between states of unequal lbar mF rbar and,along with the low (approximately 3 m/s) velocity, suppresses thesystematic effect from the motional magnetic field. The low velocity andsmall residual magnetic field have made it possible to induce transitionsbetween states and to perform state preparation, analysis, and detectionin regions free of applied static magnetic and electric fields. Thisexperiment demonstrates techniques that may be used to improve the e-EDMlimit by two orders of magnitude, but it is not in itself a sensitivee-EDM search, mostly due to limitations of the laser system.

Amini, Jason M.; Munger Jr., Charles T.; Gould, Harvey.

2007-04-05

231

The electron electric dipole moment enhancement factors of Rubidium and Caesium atoms  

International Nuclear Information System (INIS)

The enhancement factors of the electric dipole moment (EDM) of the ground states of two paramagnetic atoms; rubidium (Rb) and caesium (Cs) which are sensitive to the electron EDM are computed using the relativistic coupled-cluster theory and our results are compared with the available calculations and measurements. The possibility of improving the limit for the electron EDM using the results of our present work is pointed out

232

The electron electric dipole moment enhancement factors of Rubidium and Caesium atoms  

OpenAIRE

The enhancement factors of the electric dipole moment (EDM) of the ground states of two paramagnetic atoms; rubidium (Rb) and caesium (Cs) which are sensitive to the electron EDM are computed using the relativistic coupled-cluster theory and our results are compared with the available calculations and measurements. The possibility of improving the limit for the electron EDM using the results of our present work is pointed out.

Nataraj, H. S.; Sahoo, B. K.; Das, B. P.; Chaudhuri, R. K.; Mukherjee, D.

2007-01-01

233

Array servo scanning micro EDM of 3D micro cavities  

Science.gov (United States)

Micro electro discharge machining (Micro EDM) is a non-traditional processing technology with the special advantages of low set-up cost and few cutting force in machining any conductive materials regardless of their hardness. As well known, die-sinking EDM is unsuitable for machining the complex 3D micro cavity less than 1mm due to the high-priced fabrication of 3D microelectrode itself and its serous wear during EDM process. In our former study, a servo scanning 3D micro-EDM (3D SSMEDM) method was put forward, and our experiments showed it was available to fabricate complex 3D micro-cavities. In this study, in order to improve machining efficiency and consistency accuracy for array 3D micro-cavities, an array-servo-scanning 3D micro EDM (3D ASSMEDM) method is presented considering the complementary advantages of the 3D SSMEDM and the array micro electrodes with simple cross-section. During 3D ASSMEDM process, the array cavities designed by CAD / CAM system can be batch-manufactured by servo scanning layer by layer using array-rod-like micro tool electrodes, and the axial wear of the array electrodes is compensated in real time by keeping discharge gap. To verify the effectiveness of the 3D ASSMEDM, the array-triangle-micro cavities (side length 630 ?m) are batch-manufactured on P-doped silicon by applying the array-micro-electrodes with square-cross-section fabricated by LIGA process. Our exploratory experiment shows that the 3D ASSMEDM provides a feasible approach for the batch-manufacture of 3D array-micro-cavities of conductive materials.

Tong, Hao; Li, Yong; Yi, Futing

2011-05-01

234

Probing Charged Matter Through Higgs Diphoton Decay, Gamma Ray Lines, and EDMs  

CERN Document Server

Numerous experiments currently underway offer the potential to indirectly probe new charged particles with masses at the weak scale. For example, the tentative excess in Higgs diphoton decay and the tentative gamma-ray line in Fermi-LAT data have recently attracted attention as possible one-loop signatures of new charged particles. We explore the interplay between such signals, dark matter direct detection through Higgs exchange, and measurements of the electron EDM, by studying the size of these effects in several models. We compute one-loop effects to explore the relationship among couplings probed by different experiments. In particular, models in which dark matter and the Higgs both interact with charged particles at a detectable level typically induce, at loop level, couplings between dark matter and the Higgs that are around the level of current direct detection sensitivity. Intriguingly, one-loop Higgs diphoton decay and DM annihilation into two photons, two-loop EDMs, and loop-induced direct detection...

Fan, JiJi

2013-01-01

235

The fabrication of a micro-spiral structure using EDM deposition in the air  

International Nuclear Information System (INIS)

A novel micromachining method to deposit a micro-3D spiral structure in air using electrical discharge machining (EDM) with a brass electrode was presented. During the deposition process, a 3D spiral structure is obtained only by the feed of the z-axis in the vertical direction. Furthermore, the obtained structure can be formed and repeated stably even in the upside-down direction under a gravity environment. It is seen that the material components of a micro-spiral structure are almost the same as those of an electrode by the energy spectrum analysis of a micro-spiral structure. According to scanning electron microscope photographs, the micro-spiral appears to feature a layered material organism structure and has compact bonding with the body material. In order to understand the forming mechanism of this kind of micro-spiral structure, simulation analysis is conducted. The track of the deposition particles can be obtained by simulation, which determines the shape of the deposited structure. According to the simulation results, the track of the deposition particles is consistent with that of EDM experiments. It is further found that the distribution of the electromagnetic field in a discharge channel has an important influence on the deposited structure and the track of the deposition particles

236

Current Research Issue, Trend & Applications of Powder Mixed Dielectric Electric Discharge Machining (PM-EDM: A Review  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper new concept of manufacturing uses non-conventional energy sources like sound, light, mechanical, chemical, electrical, electrons and ions. With the industrial and technological growth, development of harder and difficult to machine materials, which find wide application in aerospace, nuclear engineering and other industries owing to their high strength to weight ratio, hardness and heat resistance qualities has been witnessed. New developments in the field of material science have led to new engineering metallic materials, composite materials and high tech ceramics having good mechanical properties and thermal characteristics as well as sufficient electrical conductivity so that they can readily be machined by spark erosion. Erosion pulse discharge occurs in a small gap between the work piece and the electrode. This removes the unwanted material from the parent metal through melting and vaporizing in presence of dielectric fluid. In recent years, EDM researchers have explored a number of ways to improve EDM Process parameters such as Electrical parameters, Non-Electrical Parameters, tool Electrode based parameters & Powder based parameters. This new research shares the same objectives of achieving more efficient metal removal rate reduction in tool wear and improved surface quality. This paper reviews the research work carried out from the inception to the development of Powder Mixed Dielectric electric Discharge Machining within the past decade. & also briefly describing the Current Research technique Trend in EDM & optimization Technique used in the Powder mix Electric Discharge Machining research field.

Sushil Kumar Choudhary

2014-07-01

237

Progress Toward Measurement of the Electron's Electric Dipole Moment Using the PbF Molecule  

Science.gov (United States)

The PbF molecule is particularly suited to a search for the electron's electric dipole moment (e-EDM.) In addition to its sensitivity to an e-EDM, its ^2?1/2 ground state provides for a small magnetic moment. Furthermore, this small magnetic moment vanishes at a magic value of electric field. This vanishing point has an experimentally observable signature: When a beam of suitably aligned ground state PbF molecules is allowed to traverse a region of electric and magnetic fields, the polarization is conserved when the electric field matches this magic value. By measuring the (molecular-frame)magnitude of this magic electric field for the case that the electric field is parallel or antiparallel to the magnetic field, sensitivity to the e-EDM is achieved. Progress toward this measurement, including the development of a continuous molecular beam source of PbF, characterization of the electronic, rotational, and hyperfine structure of the molecule, the achievement of an ultra-sensitive continuous ionization detection scheme, and the construction of a Ramsey- resonance machine are briefly summarized.

Shafer-Ray, Neil; McRaven, Christopher; Sivakumar, Poopalasingam; Rupasinghe, Milinda

2009-05-01

238

Relativistic Theory of the Electric Dipole Moment of an Atom due to the Electric Dipole Moment of an Electron  

OpenAIRE

The relativistic theory for the electric dipole moment (EDM) of paramagnetic atoms arising from the electric dipole moment of the electron is presented. A novel approach using the relativistic coupled-cluster method that incorporates the residual Coulomb interaction to all orders and a weak parity and time-reversal violating interaction to one order has been employed in Fr to obtain the enhancement of the EDM of that atom compared to the EDM of the electron. Trends of the di...

Mukherjee, Debashis; Sahoo, B. K.; Nataraj, H. S.; Das, B. P.

2009-01-01

239

Energy Data Management (EDM) in a liberalised energy market  

International Nuclear Information System (INIS)

This article discusses the role of Energy Data Management (EDM) in a liberalised Swiss energy market in the light of increasing international dynamics in this area. The requirements placed on such EDM systems are reviewed and the changes necessary in the structures and processes of electricity supply organisations are discussed. A possible design for future software systems is presented. Such systems have to be flexible enough to cover various structural possibilities as Swiss legislation on the subject has not yet been passed. The handling of data on energy-flow balances when third-party power is transferred in shared mains systems is discussed and scheduling aspects of power generation and transmission are looked at. The billing of power to customers with a free choice of supplier is looked at, as is the situation involving utilities that supply not only electricity but gas, district heating and water too

240

Optimisation of EDM fast hole drilling for aerospace applications  

Science.gov (United States)

Electrical discharge machining (EDM) fast hole drilling is a thermo-electric manufacturing process in which material removal is achieved by sparks taking place between a tool electrode and the workpiece being drilled; both covered in dielectric fluid and connected to a generator delivering periodic pulses of energy at very high frequencies. There is no physical contact between the workpiece and the electrode, and the small gap separating them is maintained under servo control. EDM fast hole drilling plays a vital role in the aerospace industry. The operating temperatures of aero-engine often exceed the melting point of the materials used in its components. Hence, it is required to artificially cool different types of components including turbine blades. This is accomplished by directing bypass air into internal passages of the blade; the air flows continuality through small holes, having diameters ranging from 0.4 to 3mm and are drilled at steep angles to the baled surfaces. With EDM it is possible to drill these holes. The EDM drilling, however, operates with very high levels of relative electrode wear and high variations in cycle times making the process rather inconsistent. Using the DOE (Design of Experiments) approach, a series of studies have been carried out with the purpose of optimising the drilling process through the evaluation of water-based dielectric fluids and electrode materials, via analysis of drilling time, electrode wear, surface integrity, dimensional accuracy and costs. Factors such as the electrode length, geometry and dielectric flushing have also been studied. This work has shown that drilling times and electrode wear can be reduced by 50% and 35% respectively depending on the type of dielectric fluid/electrode material used and on the optimisation criteria employed. Significant reductions in the variations of drilling times have also been observed. Moreover, drilling time and electrode wear can be decreased by 165% and 25% respectively, depending on the electrode geometry employed.

Leao, F. N.

241

Interrelationship among g?2, EDMs and cLFV  

International Nuclear Information System (INIS)

We summarize the status of charged lepton flavor violation (cLFV) in models beyond the SM. We stress that the current experimental bounds on cLFV processes are already constraining new physics (NP) scenarios more than the direct bounds from the LHC. On the other hand, the interrelationship among leptonic g?2, EDMs and cLFV will turn out to be of outmost importance to disentangle among different NP scenarios

242

The downsizing effect in EDM drilling of micro holes  

OpenAIRE

The recent miniaturization trend in manufacturing, has enhanced the production of new and highly sophisticated systems in various industrial fields. In recent years, machining of the so called difficult to cut materials has become an important issue in several sectors. Micro Electrical Discharge Machining (micro-EDM) thanks to its contactless nature, is one of the most important technologies for the machining of this type of materials and it can be considered as one of the most promising manu...

D Urso, Gianluca Danilo; Merla, Cristina; Maccarini, Giancarlo

2013-01-01

243

Cryogenic Design for the nEDM Experiment  

Science.gov (United States)

The neutron electric dipole moment (nEDM) measurement proposed for the Spallation Neutron Source (SNS) will provide a precision test of time reversal symmetry. Lowering the upper limit on the nEDM, currently ˜ 10-26 e.cm, by a factor of 100 would test proposed extensions to the Standard Model. Thermal neutrons from the SNS will be trapped as ultracold neutrons in two ˜ 2.2 liter cells filled with superfluid ^4He at 0.45 K. Polarized ^3He atoms dissolved into the ^4He will serve as co-magnetometers. A large dilution refrigerator (DR) will cool the cells and a surrounding 1000 liter volume of liquid helium. Transporting the ^3He to and from the cells via heat flush, and the large diameter tubes that connect volumes of superfluid liquid helium at T experimental results indicate that large heat flows occur due to superfluid film creep up the tubes and reflux of evaporated gas at higher temperatures. We have prepared an experiment to measure this effect at temperatures relevant to the nEDM experiment.

Kendellen, David; Haase, David; Huffman, Paul

2012-03-01

244

Analysis of Different Tool Material On MRR and Surface Roughness of Mild Steel In EDM  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, experiments were performed todetermine parameters effecting surface roughness (SRalong with structural analysis of surfaces with respect tomaterial removal parameters. Experimental work wasconducted on Mildl steel with copper, brass and graphiteas tool electrodes with kerosene oil as dielectric fluid.The data compiled during experimentation has beenused to yield responses in respect of material removalrate (MRR and SR. Detailed analysis of structuralfeatures of machined surface was done by usingScanning Electron Microscope (SEM and opticalmicroscope to understand the mode of heat affected zone(HAZ, which alternatively affects structure of machinedworkpiece and hence tool life. While investigatingelectric discharge machining (EDM surface bymicrographs, it was observed that molten mass has beenremoved from surface as ligaments and sheets. In somecases, it is removed as chunks, which being in moltenstate stuck to surface. All three specimens machined bydifferent electrodes showed different pattern of HAZs.

Mr. V.D.Patel*, Mr. U.J. Patel

245

CP-violating Phases in M-theory and Implications for EDMs  

CERN Document Server

We demonstrate that in effective theories arising from ${\\cal N}=1$ fluxless compactifications of M-theory on a $G_2$ manifold with low energy supersymmetry, CP-violating phases do not appear in the soft-breaking Lagrangian except via the Yukawas. Such a mechanism may be present in other string compactifications as well; we describe properties sufficient for this to occur. CP violation is generated via the Yukawas since the soft trilinear matrices are generically not proportional to the Yukawa matrices. Within the framework considered, the estimated theoretical upper bounds for electric dipole moments (EDM) of the electron, neutron and mercury are all within the current experimental limits and could be probed in the near future.

Kane, Gordon; Shao, Jing

2009-01-01

246

Search For A Permanent Electric Dipole Moment Using Atomic Indium  

CERN Document Server

We propose indium (In) as a possible candidate for observing the permanent electric dipole moment (EDM) arising from the violations of parity (P) and time-reversal (T) symmetries. This atom has been laser cooled and therefore the measurement of its EDM has the potential of improving on the current best EDM limit for a paramagnetic atom which comes from thallium. We report the results of our calculations of the EDM enhancement factor due to the electron EDM and the ratio of the atomic EDM to the electron-nucleus scalar-pseudoscalar (S-PS) interaction coupling constant in In in the framework of the relativistic coupled cluster theory. It might be possible to get new limits for the electron EDM and the S-PS CP violating coupling constant by combining the results of our calculations with the measured value of the EDM of In when it is available. These limits could have important implications for the standard model (SM) of particle physics.

Sahoo, B K; Das, B P; 10.1103/PhysRevA.84.030502

2011-01-01

247

On Measuring the Electron Electric Dipole Moment in Trapped Molecular Ions  

OpenAIRE

Trapped diatomic molecular ions could prove to be a sensitive probe for a permanent electron electric dipole moment (eEDM). We propose to use a ground or metastable $^3\\Delta_1$ level, due to its high polarizability and large EDM enhancement factor. Ions allow for simple trapping and long interrogation times, but require a time-varying electric bias field in order to probe the eEDM. We discuss experimental design as well as challenges in performing a precision spectroscopic ...

Leanhardt, Aaron E.; Bohn, John L.; Loh, Huanqian; Maletinsky, Patrick; Meyer, Edmund R.; Sinclair, Laura C.; Stutz, Russell P.; Cornell, Eric A.

2010-01-01

248

High Voltage Test Apparatus for a Neutron EDM Experiment and Lower Limit on the Dielectric Strength of Liquid Helium at Large Volumes  

CERN Document Server

A new search for a permanent electric dipole moment (EDM) of the neutron is underway using ultracold neutrons produced and held in a bath of superfluid helium. Attaining the target sensitivity requires maintaining an electric field of several tens of kilovolts per centimeter across the experimental cell, which is nominally 7.5 cm wide and will contain about 4 liters of superfluid. The electrical properties of liquid helium are expected to be sufficient to meet the design goals, but little is known about these properties for volumes and electrode spacings appropriate to the EDM experiment. Furthermore, direct application of the necessary voltages from an external source to the experimental test cell is impractical. An apparatus to amplify voltages in the liquid helium environment and to test the electrical properties of the liquid for large volumes and electrode spacings has been constructed. The device consists of a large-area parallel plate capacitor immersed in a 200 liter liquid helium dewar. Preliminary r...

Long, J C; Boissevain, J G; Clark, D J; Cooper, M D; Gómez, J J; Lamoreaux, S K; Mischke, R E; Penttila, S I

2006-01-01

249

Hedonic and utilitarian search for electronic word-of-mouth and implications on purchase value  

OpenAIRE

Online information search is often seen as a highly utilitarian task but consumers' increasingly diverse ways of using the Web have brought forth more hedonic information search patterns. At the same time, the impact of electronic word-of-mouth (eWOM) on consumer purchase decisions is increasing. The purpose of this study is to investigate the differences between hedonic and utilitarian eWOM search patterns in the light of purchase value. Using survey data from 1660 customers of two travel ag...

Po?yry, Essi

2011-01-01

250

Search for hadron jets and large transverse momentum electrons at the SPS anti p p collider  

International Nuclear Information System (INIS)

The search of high transverse momentum electrons needs the use of all the different elements of the UA2 detector; therefore the description of this search is a good way to understand the features of the apparatus, and its performance in a collider environment. We present a preliminary analysis of the UA2 data collected during the last Collider run (20 nb-1 integrated luminosity) with particular emphasis on large transverse momentum hadron jets and on electrons having the configuration expected from the decay of electroweak bosons

251

Search for muon electron conversion ?-+Ti -> e-+Ti  

International Nuclear Information System (INIS)

A progress report on a search for the lepton flavor violating reaction ?-+Ti->e-+Ti is presented. No evidence for this process has yet been found leading to an upper limit -11 (90% confidence level) relative to ordinary muon capture. (orig.)

252

The search for permanent electric dipole moments, in particular for the one of the neutron  

CERN Document Server

Nonzero permanent electric dipole moments (EDM) of fundamental systems like particles, nuclei, atoms or molecules violate parity and time reversal invariance. Invoking the CPT theorem, time reversal violation implies CP violation. Although CP-violation is implemented in the standard electro-weak theory, EDM generated this way remain undetectably small. However, this CP-violation also appears to fail explaining the observed baryon asymmetry of our universe. Extensions of the standard theory usually include new CP violating phases which often lead to the prediciton of larger EDM. EDM searches in different systems are complementary and various efforts worldwide are underway, but no finite value could be established yet. An improved search for the EDM of the neutron requires, among other things, much better statistics. At PSI, we are presently commissioning a new high intensity source of ultracold neutrons. At the same time, with an international collaboration, we are setting up for a new measurement of the ...

CERN. Geneva

2010-01-01

253

Combined Sensor Package COMARS+ for Measuring Aerothermal and Radiation Loads on the Exomars EDM Capsule Back Cover  

Science.gov (United States)

Based on the former flight instrumentation experience combined aerothermal sensor package COMARS+ has been developed to perform radiative and convective heat flux measurements on the EDM back cover TPS of ExoMars EDM flight in 2016.

Guelhan, A.; Siebe, F.; Thiele, T.

2014-06-01

254

The Goals and Mechanics of Teaching a Short Course in Electronic Search Skills to High School Students.  

Science.gov (United States)

Describes the design of a short course on electronic searching for high school students. Identifies seven steps for students to apply to an electronic search. Discusses planning the approach to instruction (a syllabus and workbook, goals, educational objectives, and evaluative criteria). Presents a 10-day schedule that organizes the seven steps…

Howe, Eleanor B.

2002-01-01

255

Search for muon to electron conversion at J-PARC: COMET experiment  

Science.gov (United States)

The COherent Muon to Electron Transition (COMET) experiment aims to search for the charged-lepton-flavor-violating process through measure muon to electron conversion in a muonic atom to very high sensitivity of 2.6 × 10-17. A two-stage approach in order to realize the experiment has been taken and the first-stage (COMET Phase-I) has been approved by KEK.

Yuan, Y.

2014-05-01

256

Computational Search for Strong Topological Insulators: An Exercise in Data Mining and Electronic Structure  

OpenAIRE

We report a data-mining investigation for the search of topological insulators by examining individual electronic structures for over 60,000 materials. Using a data-mining algorithm, we survey changes in band inversion with and without spin-orbit coupling by screening the calculated electronic band structure for a small gap and a change concavity at high-symmetry points. Overall, we were able to identify a number of topological candidates with varying structures and composition. Our overall g...

Klintenberg, M.; Haraldsen, J. T.; Balatsky, A. V.

2014-01-01

257

Vibration-assisted servo scanning 3D micro EDM  

International Nuclear Information System (INIS)

In scanning micro electrical discharge machining (EDM), the machining time for a 3D mould cavity is longer due to the smaller discharge area of a thin wire tool electrode. Moreover, a stable discharge area is hardly kept because of the scanning motion, resulting in a lower discharge ratio. To improve the machining process, a method of workpiece vibration-assisted servo scanning 3D micro EDM is developed. 3D micro structures are machined by tool electrode scanning layer by layer according to the numerical control (NC) code. Micro-amplitude assisting vibration is realized by adopting a piezoelectric (PZT) actuator driven by high-frequency sinewave voltage. Tool electrode wear is real-time compensated in the axial direction by keeping a discharge gap. A number of experiments were carried out to machine a micro rectangular cavity (900 µm × 600 µm), and the process model of vibration-assisted servo scanning EDM was established. In addition, several typical 3D micro structures have been machined. The process-model analysis and the experimental results show that the occurring frequency of the favorable discharge gap increases obviously during the machining process assisted with high-frequency vibration, so that the machining stability and the effective discharge ratio are improved. The machining efficiency increases to 6.5 times at the assisting vibration frequency of 5 kHz and the amplitude of 2.7 µm, and the material removal rate on red copper plate reaches about 1.4 n red copper plate reaches about 1.4 × 105 µm3 s?1 with a tool electrode of 100 µm in diameter

258

The use of Research Electronic Data Capture (REDCap) software to create a database of librarian-mediated literature searches.  

Science.gov (United States)

Expert-mediated literature searching, a keystone service in biomedical librarianship, would benefit significantly from regular methodical review. This article describes the novel use of Research Electronic Data Capture (REDCap) software to create a database of literature searches conducted at a large academic health sciences library. An archive of paper search requests was entered into REDCap, and librarians now prospectively enter records for current searches. Having search data readily available allows librarians to reuse search strategies and track their workload. In aggregate, this data can help guide practice and determine priorities by identifying users' needs, tracking librarian effort, and focusing librarians' continuing education. PMID:25023012

Lyon, Jennifer A; Garcia-Milian, Rolando; Norton, Hannah F; Tennant, Michele R

2014-01-01

259

Studies for obtaining a small holle, rapid edm drilling machine  

Directory of Open Access Journals (Sweden)

Full Text Available This paper studies the obtaining of an experimental rapid drilling machine, through EDM process for small holes. The best parameters such as peak current, pulse frequency, duty factor and electrode rotation speed were studied for best machining characteristics. An electrolytic copper rod 0.8 mm diameter was selected as a tool electrode. The experiments generate output responses such as maximum material removal rate (MRR and the dependence with peak current, duty factor and Electrode rotation, parameters. Finally, parameters were optimized for maximum MRR with desired surface roughness value and used for sizing the component for a better small rapid drilling machine.

Mihai ?imon

2011-12-01

260

{sup 3}He MAGNETOMETRY FOR A NEUTRON EDM MEASUREMENT  

Energy Technology Data Exchange (ETDEWEB)

The behavior of small amounts of polarized {sup 3}He in a bath of superfluid {sup 4}He at temperatures below 1 K is critical to a new technique for measuring the EDM of the neutron. We report on studies to enhance the number of ultracold neutrons produced in such a bath, on the development of neutron tomography in gaseous mixtures, on magnet properties associated with the precession of {sup 3}He, and on preparations for tests of the distribution and diffusion coefficients of {sup 3}He in the bath.

P. BANGERT; ET AL

2000-08-01

261

A novel miniaturized EDM mechanism based on linear stepping ultrasonic motor  

Science.gov (United States)

In order to machine inclined micro-holes and operate in narrow space, a novel miniaturized EDM (Electro Discharge Machining) mechanism has been developed. Because of its merit of compact size (70×40×50mm), the mechanism can be fixed on robot. The prototype of miniaturized EDM system consists of electrode direct drive unit, EDM electrical parameters and servo controller, ultrasonic EDM generator, manual robot, in addition to miniaturized EDM mechanism. Differential Reciprocating Driving Method (DRDM) is presented, and the coaxial forced vibration of electrode can be achieved. Coaxial vibration is applied to promote the evacuation of debris, and it helps to achieve stable and efficient machining. The optimal design of ultrasonic motor has been implemented using Finite Element Method (FEM), and the reasonable structure has been achieved. Feeding resolution of electrode can reach 40nm in differential reciprocating style. The holes with figures of ?85?m circle, ?90?m inclined circle, Y and inclined Y have been machined.

Tang, Y. J.; Hu, F. Q.; Wang, Z. L.; Zhao, W. S.

2005-12-01

262

A fatigue study of electrical discharge machine (EDM) strain-gage balance materials  

Science.gov (United States)

A fatigue study was undertaken to determine how much electrical-discharge-machine (EDM) processing affected the fatigue life of balance materials: EDM and regular milling-machine (MM) samples were compared. Simulation of a typical balance stress configuration was devised for the fatigue testing in order to obtain results more closely related to balance situations. The fatigue testing of the EDM and MM specimens has indicated that the EDM technique does indeed reduce the fatigue life of 15-5PH steel, the first balance material tested. This conclusion was based on comparisons of the specimen fatigue lives with theoretical and manufacturer's data. Hence the EDM surface effects are detrimental to the fatigue life of this balance material.

Rhew, Ray D.

1989-01-01

263

An on-line monitoring system for a micro electrical discharge machining (micro-EDM) process  

Science.gov (United States)

A pulse-type discriminating system to monitor the process of micro electrical discharge machining (micro-EDM) is developed and implemented. The specific features are extracted and the pulses from a RC-type power source are classified into normal, effective arc, transient short circuit and complex types. An approach to discriminate the pulse type according to three durations measured at three pre-determined voltage levels of a pulse is proposed. The developed system is verified by using simulated signals. Discrimination of the pulse trains in actual machining processes shows that the pulses are mainly the normal type for micro wire-EDM and micro-EDM milling. The pulse-type distribution varies during the micro-EDM drilling process. The percentage of complex-type pulse increases monotonically with the drilling depth. It starts to drop when the gap condition is seriously deteriorated. Accordingly, an on-line monitoring strategy for the micro-EDM drilling process is proposed.

Liao, Y. S.; Chang, T. Y.; Chuang, T. J.

2008-03-01

264

Torque for electron spin induced by electron permanent electric dipole moment  

Science.gov (United States)

The spin torque of the electron is studied in relation to the electric dipole moment (EDM) of the electron. The spin dynamics is known to be given by the spin torque and the zeta force in quantum field theory. The effect of the EDM on the torque of the spin brings a new term in the equation of motion of the spin. We study this effect for a solution of the Dirac equation with electromagnetic field.

Senami, Masato; Fukuda, Masahiro; Ogiso, Yoji; Tachibana, Akitomo

2014-10-01

265

Torque for electron spin induced by electron permanent electric dipole moment  

International Nuclear Information System (INIS)

The spin torque of the electron is studied in relation to the electric dipole moment (EDM) of the electron. The spin dynamics is known to be given by the spin torque and the zeta force in quantum field theory. The effect of the EDM on the torque of the spin brings a new term in the equation of motion of the spin. We study this effect for a solution of the Dirac equation with electromagnetic field

266

The Cold Dark Matter Search test stand warm electronics card  

Energy Technology Data Exchange (ETDEWEB)

A card which does the signal processing for four SQUID amplifiers and two charge sensitive channels is described. The card performs the same functions as is presently done with two custom 9U x 280mm Eurocard modules, a commercial multi-channel VME digitizer, a PCI to GPIB interface, a PCI to VME interface and a custom built linear power supply. By integrating these functions onto a single card and using the power over Ethernet standard, the infrastructure requirements for instrumenting a Cold Dark Matter Search (CDMS) detector test stand are significantly reduced.

Hines, Bruce; /Colorado U., Denver; Hansen, Sten; /Fermilab; Huber, Martin; /Colorado U., Denver; Kiper, Terry; /Fermilab; Rau, Wolfgang; /Queen' s U., Kingston; Saab, Tarek; /Florida U.; Seitz, Dennis; Sundqvist, Kyle; /UC, Berkeley; Mandic, Vuk; /Minnesota U.

2010-11-01

267

Dark Matter Search by High-Energy Electron Observations  

Science.gov (United States)

It has been pointed out in particle physics that mono-energetic electrons and positrons can be produced in the annihilation of WIMP dark matter. Although the propagation through the Galaxy would broaden the line spectrum, the observed spectrum would still have the distinctive feature in the region of sub-TeV, which indicates the existence of WIMP dark matter in the Galactic halo. The recent positron fraction spectrum by the PAMELA experiment shows a significant sharp rise up to ˜100 GeV, and the electron + positron spectrum by the ATIC experiment also shows an excess in the several 100 GeV region. In order to increase greatly the amount of statistics up to higher energies, we need to observe the high-energy electrons and positrons for much longer exposure times by space utilization such as CALET on the ISS.

Yoshida, Kenji; Torii, Shoji; Kasahara, Katsuaki; Shimizu, Yuki; Tamura, Tadahisa

268

Taguchi Method Implementation in Taper Motion Wire EDM Process Optimization  

Science.gov (United States)

Wire electrical discharge machining (Wire EDM) is a non-conventional metal removal process as well as one of the best manufacturing processes suitable for producing jigs, fixtures, and dies. Among others, the machine is able to cut a workpiece having oblique and taper form. The objective of this paper is to optimize the input parameters of Wire EDM machine, such as no load voltage, capacitor, on-time, off-time, and servo voltage, for machining medium carbon steel ASSAB 760. The Taguchi design of experiments, the signal-to-noise ratio, and analysis of variance are employed to analyze the effects of the input parameters by adopting L18 Taguchi orthogonal array (OA) to conduct experiments using brass wire electrode of 0.2 mm in diameter. In order to achieve the maximum material removal rate (MRR) or the minimum surface roughness (SR), six controllable factors, i.e., the parameters of each at three levels are applied for determining the optimal combination of factors and levels. The results reveal that the MRR and the SR are greatly influenced by the on-time and the taper angle, respectively. Experimental results affirm the effectiveness of the method, and also prove that the Taguchi method is suitable to solving the stated problem within minimum number of experiments as compared to that of a full factorial design.

Martowibowo, S. Y.; Wahyudi, A.

2012-10-01

269

Review of Wire-Cut EDM Process on Titanium alloy  

Directory of Open Access Journals (Sweden)

Full Text Available Wire electrical discharge machining (WEDM is a specialized thermal machining process capable of accurately machining parts with varying hardness or complex shapes, which have sharp edges that are very difficult to be machined by the main stream machining processes. This practical technology of the WEDM process is based on the conventional EDM sparking phenomenon utilizing the widely accepted non-contact technique of material removal. Since the introduction of the process, WEDM has evolved from a simple means of making tools and dies to the best alternative of producing micro-scale parts with the highest degree of dimensional accuracy and surface finish quality. This paper reviews the vast array of research work carried out from the EDM process to the development of the WEDM. It reports on the WEDM research involving the optimization of the process parameters surveying the influence of the various factors affecting the machining performance and productivity on titanium alloy (Ti6Al4V.This paper reviews the effects of various WEDM process parameters such as pulse on time, pulse off time, servo voltage, peak current, dielectric flow rate, wire speed, wire tension on different process responseparameters such as material removal rate (MRR, surface roughness(Ra, Kerf (width of Cut, wire wear ratio (WWR and surface integrity factors.

Vijay D. Patel

2014-12-01

270

Search for multiple electron scattering sequences in simple systems  

International Nuclear Information System (INIS)

Complete text of publication follows. Double differential spectra of electrons ejected in ion-atom or ion-solid collisions are in the focus of general interest for a long time. These spectra are relatively easy to measure, and they show many fine details relevant for the collisions dynamics. In the past decade special effort has been devoted to understand the high energy part of the electron spectra. Significantly enhanced emission of fast electrons far above the so-called binary encounter energy was observed in both ion-atom and ion-solid collisions. In some cases, fast electrons have been identified from double, triple and quadruple scattering by the projectile and target cores. The ejected electron gains energy in every encounter with the projectile in such processes. This mechanism is often referred to as Fermi-shuttle acceleration. Most of the experiments were performed with dressed heavy projectiles and heavy target atoms, where the cross section is large enough for observing multiple scattering processes. No quantum calculations were possible at such complexity, only classical trajectory Monte-Carlo (CTMC) calculations have been performed for modeling these collisions. Surprisingly, quantitative agreement has been found for many collision systems. Moreover, the analysis of the classical particle trajectories allows one to identify multiple scattering events in the classical sense. The aim of this work is to study the process for simpler collision systems, whichocess for simpler collision systems, which can be handled by both classical and quantum calculations. The relevant cross sections might be too small to be measured, but they can be identified and compared in classical and quantum calculations. In the present work, as a first step, we apply the CTMC method for 25 keV He2+ + H collisions at selected impact parameter (b) values. The first results, calculated differential ionization probabilities at b = 0.05 a.u, are shown in Fig. 1. The electron yield above 13.6 eV kinetic energy is expected to originate from multiple scattering. An additional feature is the predicted large enhancement of the electron yield at backward observation angles

271

Search for electric dipole moments at storage rings  

CERN Document Server

Permanent electric dipole moments (EDMs) violate parity and time reversal symmetry. Within the Standard Model (SM) they are many orders of magnitude below present experimental sensitivity. Many extensions of the SM predict much larger EDMs, which are therefore an excellent probe for the existence of "new physics". Until recently it was believed that only electrically neutral systems could be used for sensitive searches of EDMs. With the introduction of a novel experimental method, high precision for charged systems will be within reach as well. The features of this method and its possibilities are discussed.

Onderwater, Gerco

2012-01-01

272

Search for muon-electron and muon-positron conversion  

International Nuclear Information System (INIS)

Limits on the lepton flavor violating reactions ?-+Z?e-+Z and ?-+Z?e++(Z-2), muon-electron and muon-position conversion, have been obtained. Upper limits (90% C.L.) for the branching ratios compared to ordinary muon capture are: R/sub -/(Ti) = ?(?-Ti?e-Ti)/?(?-Ti capture)-12, R/sub +/(Ti) = ?(?-Ti?d+Ca*)/?(?-Ti capture)-10 and R/sub -/(Pb)-10

273

Handsearching versus electronic searching to identify reports of randomized trials.  

OpenAIRE

BACKGROUND: Systematic reviewers need to decide how best to reduce bias in identifying studies for their review. Even when journals are indexed in electronic databases, it can still be difficult to identify all relevant studies reported in these journals. Over 1700 journals have been or are being handsearched within The Cochrane Collaboration to identify reports of controlled trials in order to help address these problems. OBJECTIVES: To review systematically empirical studies, which have com...

Hopewell, S.; Clarke, M.; Lefebvre, C.; Scherer, R.

2007-01-01

274

Membrane-associated electron-dense material of the asexual stages of Plasmodium falciparum: evidence for movement from the intracellular parasite to the erythrocyte membrane.  

Science.gov (United States)

Electron-dense material (EDM) appears at the parasite plasma membrane with trophozoites of several strains of Plasmodium falciparum cultured in vitro. The EDM is also seen associated with unit membrane-bounded Maurer's clefts in K+ P. falciparum-infected erythrocytes. The cytoplasmic clefts lack the EDM with K- parasites. Some EDM have the same density and appearance as the material located under knobs at the erythrocyte membrane. The EDM at the parasite plasma membrane is absent with schizonts when expression of new knobs at the erythrocyte membrane appears to have ceased. This electron microscopic study suggests that the parasite-derived EDM is transported from the parasite plasmalemma to the erythrocyte membrane via Maurer's clefts in the erythrocyte cytoplasm. PMID:3511749

Aikawa, M; Uni, Y; Andrutis, A T; Howard, R J

1986-01-01

275

A search for excited fermions in electron-proton collisions at HERA  

International Nuclear Information System (INIS)

A search for excited states of the standard model fermions was performed using the ZEUS detector at the HERA electron-proton collider, operating at a centre of mass enery of 296 GeV. In a sample corresponding to an integrated luminosity of 0.55 pb-1, no evidence was found for any resonant state decaying into final states composed of a fermion and a gauge boson. Limits on the coupling strength times branching ratio of excited fermions are presented for masses between 50 GeV and 250 GeV, extending previous search regions significantly. (orig.)

276

Evaluating the electrical discharge machining (EDM) parameters with using carbon nanotubes  

International Nuclear Information System (INIS)

Electrical discharge machining (EDM) is one of the most accurate non traditional manufacturing processes available for creating tiny apertures, complex or simple shapes and geometries within parts and assemblies. Performance of the EDM process is usually evaluated in terms of surface roughness, existence of cracks, voids and recast layer on the surface of product, after machining. Unfortunately, the high heat generated on the electrically discharged material during the EDM process decreases the quality of products. Carbon nanotubes display unexpected strength and unique electrical and thermal properties. Multi-wall carbon nanotubes are therefore on purpose added to the dielectric used in the EDM process to improve its performance when machining the AISI H13 tool steel, by means of copper electrodes. Some EDM parameters such as material removal rate, electrode wear rate, surface roughness and recast layer are here first evaluated, then compared to the outcome of EDM performed without using nanotubes mixed to the dielectric. Independent variables investigated are pulse on time, peak current and interval time. Experimental evidences show that EDM process operated by mixing multi-wall carbon nanotubes within the dielectric looks more efficient, particularly if machining parameters are set at low pulse of energy.

277

Computational Atomic Structure and Search for New Physics  

Science.gov (United States)

The overarching goal of this dissertation is to examine constraints on extensions to the Standard Model (SM) through atomic-structure computations. More specifically, atomic parity-nonconserving (PNC) amplitudes and intrinsic electric dipole moments (EDM) are examined for sources of physics beyond the SM. Precision calculations of these properties in the trivalent thallium atom, will help set new constraints on searches beyond the SM. To this end, the first half of the dissertation is devoted to improving atomic structure calculations. In particular, we numerically investigate the effectiveness of two convergence methods for coupled-cluster (CC) method. Further we explore the feasibility of transferring high-precision CC methods, developed for monovalent atoms, to trivalent systems. Here we showcase calculations of various properties of the trivalent atomic boron as a prototype for future precision computations for thallium. In the second half of the dissertation, we consider "dark force" extensions to the SM. We introduce "dark forces" by considering the parity-odd as well as simultaneous parity-and time-reversal-violating interactions between atomic electrons and nucleons. Here we hypothesize the exchange of a "dark sector" light gauge-boson particle between atomic electrons and nucleons, as the source of the "dark force". Furthermore, using the latest experimental upper limits on mercury EDM and error bars on the cesium PNC experiments, we place constraints on the coupling strengths of such "dark forces" with ordinary matter.

Gharibnejad, Heman

278

A search for electron cyclotron maser emission from compact binaries  

OpenAIRE

Unipolar induction (UI) is a fundamental physical process, which occurs when a conducting body transverses a magnetic field. It has been suggested that UI is operating in RX J0806+15 and RX J1914+24, which are believed to be ultra-compact binaries with orbital periods of 5.4 min and 9.6 min respectively. The UI model predicts that those two sources may be electron cyclotron maser sources at radio wavelengths. Other systems in which UI has been predicted to occur are short pe...

Ramsay, Gavin; Brocksopp, Catherine; Wu, Kinwah; Slee, Bruce; Saxton, Curtis

2007-01-01

279

Search for a permanent electric-dipole moment using atomic indium  

International Nuclear Information System (INIS)

We propose indium (In) as a possible candidate for observing the permanent electric dipole moment (EDM) arising from violations of parity (P) and time-reversal (T) symmetries. This atom has been laser cooled and therefore the measurement of its EDM has the potential of improving on the current best EDM limit for a paramagnetic atom, which comes from thallium. We report the results of our calculations of the EDM enhancement factor due to the electron EDM and the ratio of the atomic EDM to the electron-nucleus scalar-pseudoscalar (S-PS) interaction coupling constant in In within the framework of the relativistic coupled cluster theory. It might be possible to get new limits for the electron EDM and the S-PS CP-violating coupling constant by combining the results of our calculations with the measured value of the EDM of In when it is available. These limits could have important implications for the standard model (SM) of particle physics.

280

Search for a permanent electric-dipole moment using atomic indium  

Science.gov (United States)

We propose indium (In) as a possible candidate for observing the permanent electric dipole moment (EDM) arising from violations of parity (P) and time-reversal (T) symmetries. This atom has been laser cooled and therefore the measurement of its EDM has the potential of improving on the current best EDM limit for a paramagnetic atom, which comes from thallium. We report the results of our calculations of the EDM enhancement factor due to the electron EDM and the ratio of the atomic EDM to the electron-nucleus scalar-pseudoscalar (S-PS) interaction coupling constant in In within the framework of the relativistic coupled cluster theory. It might be possible to get new limits for the electron EDM and the S-PS CP-violating coupling constant by combining the results of our calculations with the measured value of the EDM of In when it is available. These limits could have important implications for the standard model (SM) of particle physics.

Sahoo, B. K.; Pandey, R.; Das, B. P.

2011-09-01

281

Development of high-homogeneity magnetic field coil for 129Xe EDM experiment  

Science.gov (United States)

We search for 129Xe EDM by using an active nuclear spin maser. In this experiment, the amplitude of the maser oscillation signal is one of the most important parameters that eventually determine the frequency precision. The amplitude is proportional to the ratio of the transverse spin relaxation time T 2 to the effective longitudinal spin relaxation time T1^{ast }. In particular, for a spin maser of 3He (a co-magnetometer) for which T1^{ast } typically reaches ˜50 h, a long T 2 is needed. T 2 depends on the homogeneity of the magnetic field which is applied with coils in order to keep the spins under precession. In the present report, we discuss on the design and construction of a new coil which provided a root-mean square (rms) field gradient of less than 5.0 ?G/cm. The result of the field measurement has shown that the field gradient in the cell fulfills the target condition ?{} measured to be as long as 11,000 s.

Sakamoto, Y.; Bidinosti, C. P.; Ichikawa, Y.; Sato, T.; Ohtomo, Y.; Kojima, S.; Funayama, C.; Suzuki, T.; Tsuchiya, M.; Furukawa, T.; Yoshimi, A.; Ino, T.; Ueno, H.; Matsuo, Y.; Fukuyama, T.; Asahi, K.

2015-02-01

282

The Investigation of EDM Parameters on Electrode Wear Ratio  

Directory of Open Access Journals (Sweden)

Full Text Available Electrical Discharge Machining (EDM is a well-established machining option for manufacturing geometrically complex or hard material parts that are extremely difficult-to-machine by conventional machining processes. The non-contact machining technique has been continuously evolving from a mere tool and die making process. In this study, the influence of different electro discharge machining parameters (current, pulse on-time, pulse off-time, arc voltage on the electrode wear ratio as a result of application copper electrode to hot work steel DIN1.2344 has been investigated. Design of the experiment was chosen as full factorial. Artificial neural network has been used to choose proper machining parameters and to reach certain electrode wear ratio. Finally a hybrid model has been designed to reduce the artificial neural network errors. The experiment results indicated a good performance of proposed method in optimization of such a complex and non-linear problems.

Reza Atefi

2012-05-01

283

Fabrication Of Micro-Nozzles Via ?-EDM Process  

Science.gov (United States)

Since traditional handling mechanisms have an unpredictable behavior at micro scale, micro-assembly is a bottleneck in the development of hybrid micro-systems, and the development of new approaches is strongly demanded. In this paper, a recent study of the fabrication of a ceramics vacuum micro-gripper to handle parts in the range of hundreds of microns (300-1000) is presented. Among the possible micro manufacturing processes, micro-EDM has been selected as proving to be a very competitive fabrication technology for the manufacturing of ultra miniature components and micro sized features. The influence of the process parameters on the machining performance of interest is firstly investigated; then, the experimental results on machining the micro gripper are presented, finally concluding remarks are given.

Modica, F.; Ferraris, E.; Trotta, G.; Fassi, I.; Reynaerts, D.

2011-01-01

284

Fabrication Of Micro-Nozzles Via ?-EDM Process  

International Nuclear Information System (INIS)

Since traditional handling mechanisms have an unpredictable behavior at micro scale, micro-assembly is a bottleneck in the development of hybrid micro-systems, and the development of new approaches is strongly demanded. In this paper, a recent study of the fabrication of a ceramics vacuum micro-gripper to handle parts in the range of hundreds of microns (300-1000) is presented. Among the possible micro manufacturing processes, micro-EDM has been selected as proving to be a very competitive fabrication technology for the manufacturing of ultra miniature components and micro sized features. The influence of the process parameters on the machining performance of interest is firstly investigated; then, the experimental results on machining the micro gripper are presented, finally concluding remarks are given.

285

The search for electric dipole moments of light ions in storage rings  

International Nuclear Information System (INIS)

The Standard Model (SM) of Particle Physics is not capable of accounting for the apparent matter-antimatter asymmetry of our universe. Physics beyond the SM is required and is searched for by (i) employing highest energies (e.g., at LHC), and (ii) striving for ultimate precision and sensitivity (e.g., in the search for electric dipole moments (EDMs)). Permanent EDMs of particles violate both time reversal (T) and parity (P) invariance, and are via the CPT-theorem also CP-violating. Finding an EDM would be a strong indication for physics beyond the SM, and reducing upper limits further provides crucial tests for any corresponding theoretical model, e.g., SUSY. Direct searches for proton and deuteron EDMs bear the potential to reach sensitivities beyond 10?29 e·cm. For an all-electric proton storage ring, this goal is pursued by the US-based srEDM collaboration [1], while the newly founded Jülich-based JEDI collaboration [2] is pursuing an approach using a combined electric-magnetic lattice, which shall provide access to the EDMs of protons, deuterons, and 3He ions in the same machine. In addition, JEDI has recently proposed making a direct measurement of the proton and/or deuteron EDM at COSY using resonant techniques involving Wien filters

286

Searches for unstable neutral leptons in low-multiplicity events from electron-positron annihilation  

International Nuclear Information System (INIS)

Upper limits are given on the production of unstable neutral leptons in electron-positron annihilation at 29 GeV. The searches use selected two- and four-charged-particle events and are most sensitive to neutral-lepton masses of the order of 1 GeV/c2 and smaller. However, results are given for masses up to 14 GeV/c2

287

A search for muon-to-electron conversion at J-PARC: the COMET experiment  

Science.gov (United States)

A new experimental search for the charged-lepton-flavor-violating process of neutrinoless muon-to-electron conversion by J-PARC E21 (the COMET experiment), which aims at a factor of 10 000 improvement over the current limit, is described, together with the physics motivation of charged lepton flavor violation. The first-stage approach of the COMET experiment (COMET Phase-I), which has recently been taken for earlier realization of the measurement, is also mentioned.

Kuno, Yoshitaka

2013-02-01

288

Development of electronic information search and documentation system to preserve knowledge about fast reactors  

International Nuclear Information System (INIS)

The necessity to preserve the knowledge gained in the process of fast reactors development and operation is quite obvious. For this purpose it is necessary to set up electronic libraries and suitable search systems. All the documents that contain certain information about the objects from the given field of knowledge can be referred to as sources of knowledge, i.e. they are articles, preprints, papers, clarification notes, reports, catalogs and other sources. These sources of knowledge can be found in various places, institutions, archives, etc. Usually they are kept in libraries. These sources can have different forms, e.g. electronic, printed, photo, microfiche, etc. The information about these sources of knowledge is placed in catalogs that make the process of searching for required documents much easier. Catalogs usually have a subject heading identifier, index of authors, index of topics, key words and summaries. In a certain sense, catalogs can be also considered as sources of knowledge. There are a lot of various sources of knowledge and experience in the nuclear industry under the subject of 'Fast Reactors'. All of them are in different states in terms of convenience of their use and even possibility to use this knowledge and experience once again. In the best case these sources are in the form of electronic documents that contain not only the information about certain knowledge and experience but this very knowledge and experience in the digitized electronic nd experience in the digitized electronic form. These types of catalogs are the most suitable and simple for their use. There are libraries where knowledge and experience are only kept as nondigitized images of documents. It is not so convenient to work with this information but still it is quite real to get it. If a catalogs only contains information about knowledge and experience but neither is available in electronic form, then in order to get the access to this information it will be necessary either to digitize it or to get its non-electronic copy (usually, hard copy). But even if the entire scope of information about knowledge and experience is presented in electronic catalogs, nevertheless there will be a certain problem to work with it, as to work with a lot of intangible sources may turn out to be much more time- and labor-consuming than to work with it within a single system. Two problems have to be solved in terms of knowledge preservation. The first one is related to transformation of all the sources into electronic form. The second one is related to effective search for the required information by means of the catalogs available. The first problem can be solved rather easily. All the published sources of knowledge can be scanned and transformed into electronic form. Thus, instead of printed catalogs that contain the information about sources of knowledge there will be electronic catalogs. Though this activity seems rather simple, it is still very labor-and time-consuming, because the number of these sources is tremendous. We cannot say that the first problem can be promptly solved because it will require not only great financial expenses but also significant organizational efforts. To solve the second problem is much more complicated, as currently there are no effective search systems oriented towards a specific field of knowledge that could run in heterogeneous and worldwide search environment. At the same time this problem can be solved much faster than the first one, because in this case we mean the development of a software product independent of any organizational measures. The conditions required to cope with this problem imply the availability of electronic catalogs that contain the information about sources of knowledge and their accessibility in the computer network

289

Towards the effective tool wear control in micro-EDM milling  

DEFF Research Database (Denmark)

The electrode wear in micro-electrical discharge milling (micro-EDM milling) is one of the main problems to be solved in order to improve machining accuracy. This paper presents an investigation on wear and material removal in micro-EDM milling for selected process parameter combinations typical of rough and finish machining of micro-features in steel. The experiments were performed on state-of-the-art micro-EDM equipment. Based on discharge counting and volume measurements, electrode wear per discharge and material removal per discharge were measured for several energy levels. The influence of the accuracy of volume measurements on the electrode wear per discharge and on the material removal per discharge are discussed, and the issues limiting the applicability of real time wear sensing in micro-EDM milling are presented.

Bissacco, Giuliano; Valentincic, J.

2010-01-01

290

Verification of EDMS effective dose methodology by 3-D image based Monte Carlo simulations  

International Nuclear Information System (INIS)

Implementing effective dose in radiation protection is defined as a weighted average of organ doses to 23 organs and tissue in a human body. The effective dose has been measured, for some research purpose, by inserting hundreds of TLD chips to an anthropomorphic physical phantom of calculated by a Monte Carlo radiation transport simulation. However, both of these approaches are very complicated and cannot be used in the fields by practicing health physicists. A measurement system called Effective Dose Measurement System(EDMS) is being developed at Hanyang University. In this study, we verified EDMS effective dose methodology using Monte Carlo simulation and the preliminary measurement. First, this study investigated radiological characterization of the High-sensitivity MOSFET dosimeter using Monte Carlo simulation and experiment. Also, we decided Energy Dependence Correction Factor(EDCF) of each MOSFET dosimeter. This study developed Hybrid Voxel Anthropomorphic Phantom(HVAP) to calculate uncertainty of effective dose due to use of a limited number of dosimeters. The errors of EDMS effective dose methodology are not significant (less than a 6%) considering all photon energies and irradiation geometries in this study. Then, we measured prototype EDMS in radiation fields(C0-60 and Cs-137). The result of EDMS effective dose measurement compared with Monte Calro simulation of the MIRD-type mathematical phantom. Because the ATOM phantom was different from MIRD-type model uantom was different from MIRD-type model used in the simulation, the differences in effective doses are within 13%. Also, the error of EDMS found to be about 10% adding up radiological characterization of the High-sensitivity MOSFET dosimeter, the errors of EDMS effective dose methodology and the errors of Energy Dependence Correction Factor. The results of this study will be used in order to EDMS development. We will develop the software for data acquisition and effective dose calculation

291

Optimization of EDM Process Parameters on Titanium Super Alloys Based on the Grey Relational Analysis  

OpenAIRE

Electrical discharge machining (EDM) is a unconventional machining process for the machining of complex shapes and hard materials that are difficult of machining by conventional machining process. In this paper deals with the optimization of EDM process parameters using the grey relational analysis (GRA) based on an orthogonal array for the multi response process. The experiments are conducted on Titanium super alloys with copper electrode based on the Taguchi ...

J Laxman, Dr K. Guru Raj

2014-01-01

292

Measuring the electric dipole moment of the electron with YbF molecules  

International Nuclear Information System (INIS)

A molecular beam interferometer has been built. The interferometer is capable of measuring spectacularly small shifts in energy levels of the YbF molecule, such as those that might be induced if the electron has an electric dipole moment (EDM). This device has been used to make a precise measurement of the electron EDM. The result, (-0.3 ± 4.0) x 10-26 e · cm, is the most sensitive measurement of the electron EDM made in a molecular environment. Furthermore, the results indicate that further work could substantially increase this sensitivity. (author)

293

Development of an Eco-Friendly Electrical Discharge Machine (E-EDM) Using TRIZ Approach  

Science.gov (United States)

Electrical Discharge Machine (EDM) is one of the non-traditional machining processes. EDM process is based on thermoelectric energy between the work and an electrode. A pulse discharge occurs in a small gap between the work piece and the electrode and removes the unwanted material from the parent metal through melting and vaporization. The electrode and the work piece must have an electrical conductivity in order to generate the spark. Dielectric fluid acts as a spark conductor, concentrating the energy to a very narrow region. There are various types of products can be produced and finished using EDM such as Moulds, Dies, Parts of Aerodynamics, Automotives and Surgical components. This research work reveals how an Eco friendly EDM (E-EDM) can be modeled to replace die electric fluid and introducing ozonised oxygen in to EDM to eliminate harmful effects generated while machining by using dielectric, to make pollution free machining environment through a new design of EEDM using TRIZ (a Russian acronym for Theory of Inventive Problem Solving) approach, since Eco friendly design is the need of the hour.

Sreebalaji, V. S.; Saravanan, R.

294

Relations between matrix elements of different weak interactions and interpretation of the parity-nonconserving and electron electric-dipole-moment measurements in atoms and molecules  

Science.gov (United States)

The relations between matrix elements of different (P,T)-odd weak interactions are derived. We demonstrate that similar relations hold for parity-nonconserving transition amplitudes and electron electric dipole moments (EDMs) of atoms and molecules. This allows one to express P- and T-odd effects in many-electron systems caused by different symmetry-breaking mechanisms via each other using simple analytical formulas. We use these relations for the interpretation of the anapole moment measurements in cesium and thallium and for the analysis of the relative contributions of the scalar-pseudoscalar CP-odd weak interaction and electron EDMs to the EDMs of Cs, Tl, Fr, and other atoms and many polar molecules (YbF, PbO, ThO, etc.). Model-independent limits on electron EDMs and the parameter of the scalar-pseudoscalar CP-odd interaction are found from the analysis of the EDM measurements for Tl and YbF.

Dzuba, V. A.; Flambaum, V. V.; Harabati, C.

2011-11-01

295

Relations between matrix elements of different weak interactions and interpretation of the parity-nonconserving and electron electric-dipole-moment measurements in atoms and molecules  

International Nuclear Information System (INIS)

The relations between matrix elements of different (P,T)-odd weak interactions are derived. We demonstrate that similar relations hold for parity-nonconserving transition amplitudes and electron electric dipole moments (EDMs) of atoms and molecules. This allows one to express P- and T-odd effects in many-electron systems caused by different symmetry-breaking mechanisms via each other using simple analytical formulas. We use these relations for the interpretation of the anapole moment measurements in cesium and thallium and for the analysis of the relative contributions of the scalar-pseudoscalar CP-odd weak interaction and electron EDMs to the EDMs of Cs, Tl, Fr, and other atoms and many polar molecules (YbF, PbO, ThO, etc.). Model-independent limits on electron EDMs and the parameter of the scalar-pseudoscalar CP-odd interaction are found from the analysis of the EDM measurements for Tl and YbF.

296

The electric dipole moment of an electron in H-like ions in an electrostatic storage ring  

CERN Document Server

Theoretical studies are presented how the electric dipole moment (EDM) of the electron in H-like ions in electrostatic storage rings can sensitively be determined. With the proposed experiments a new constraint of about $10^{-29}$ e cm for the electron EDM can be established what is by an order of magnitude more restrictive than the existing bounds. Experiments with H-like ions may provide a possibility to distinguish between the electron EDM effect and the effect of P,T violating interaction between the atomic electron and the nucleus.

Bondarevskaya, A A; Andreev, O Yu; Mistonova, E A; Labzowsky, L N; Plunien, G; Liesen, D; Bosch, F

2014-01-01

297

Energies, transition rates, and electron electric dipole moment enhancement factors for Ce IV and Pr V  

OpenAIRE

Energies, transition rates, and electron electric dipole moment (EDM) enhancement factors are calculated for low-lying states of Ce IV and Pr V using relativistic many-body perturbation theory. This study is related to recent investigations of the more complicated Gd IV ion, which is promising for electron EDM experiments. The ions Ce IV and Pr V both have a single valence electron, permitting one to carry out reliable ab-initio calculations of energy levels, transition rate...

Savukov, I. M.; Johnson, W. R.; Safronova, U. I.; Safronova, M. S.

2002-01-01

298

CALET investigation of the origin of cosmic-ray electrons and search for dark matter  

Science.gov (United States)

The CALorimetric Electron Telescope, CALET, is a new all-sky gamma-ray and electron obser-vatory being developed for the Exposure Facility of Japanese Experiment Module (JEM-EF) on the International Space Station (ISS). The main instrument consists of an imaging calorimeter of scintillating fibers, IMC, a total absorption calorimeter of BGO, TASC, and silicon pixel ar-ray, SIA. CALET has a unique capability to observe high-energy electrons in 1GeV -10TeV and gamma rays in 10GeV -several TeV with an energy resolution better than a few percent above 100 GeV, an angular resolution of 0.1deg above 100GeV, and a hadron rejection power larger than 105 . The high precise measurements of electron energy spectrum and arrival directions enable us to detect distinctive features from nearby cosmic-ray electron sources and WIMP dark matter. Excellent energy resolution of CALET, which is much better than Fermi-LAT or air Cherenkov telescopes, is also ideal to detect gamma-ray lines in the GeV-TeV region from WIMP dark matter. In this paper, we present scientific prospects of CALET for investigation of the origin of cosmic-ray electrons and dark matter search.

Yoshida, Kenji; Torii, Shoji; Kasahara, Katsuaki; Akaike, Yosui; Tamura, Tadahisa; Mori, Masaki; Ioka, Kunihito; Kawanaka, Norita

299

Search for pair production of the scalar top quark in the electron+muon final state  

Energy Technology Data Exchange (ETDEWEB)

We report the result of a search for the pair production of the lightest supersymmetric partner of the top quark ({tilde t}{sub 1}) in p{bar p} collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider corresponding to an integrated luminosity of 5.4 fb{sup -1}. The scalar top quarks are assumed to decay into a b quark, a charged lepton, and a scalar neutrino ({tilde {nu}}), and the search is performed in the electron plus muon final state. No significant excess of events above the standard model prediction is detected, and improved exclusion limits at the 95% C.L. are set in the (M{sub {tilde t}{sub 1}}, M{sub {tilde {nu}}}) mass plane.

Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Alexeev, G.D.; Alkhazov, G.; Altona, A.; Alverson, G.; Alves, G.A.

2010-09-01

300

A search for muon neutrino to electron neutrino oscillations in the MINOS Experiment  

Energy Technology Data Exchange (ETDEWEB)

We perform a search for {nu}{sub {mu}} {yields} {nu}{sub e} oscillations, a process which would manifest a nonzero value of the {theta}{sub 13} mixing angle, in the MINOS long-baseline neutrino oscillation experiment. The analysis consists of searching for an excess of {nu}{sub e} charged-current candidate events over the predicted backgrounds, made mostly of neutral-current events with high electromagnetic content. A novel technique to select electron neutrino events is developed, which achieves an improved separation between the signal and the backgrounds, and which consequently yields a better reach in {theta}{sub 13}. The backgrounds are predicted in the Far Detector from Near Detector measurements. An excess is observed in the Far Detector data over the predicted backgrounds, which is consistent with the background-only hypothesis at 1.2 standard deviations.

Ochoa Ricoux, Juan Pedro; /Caltech

2009-10-01

301

Searching for New Physics beyond the Standard Model in Electric Dipole Moment  

CERN Document Server

This is the theoretical review of exploration of new physics beyond the Standard Model (SM) in electric dipole moment (EDM) in elementary particles, atoms, and molecule. EDM is very important CP violating phenomenon and sensitive to new physics. Starting with the estimations of EDM of quarks-leptons in the SM, we explore the new signals beyond the SM. However, these works drive us to more wide fronteers where we serach fundamental physics using atoms and molecules and vice versa. Paramagnetic atoms and molecules have great enhancement factor on electron EDM. Diamagnetic atoms and molecules are very sensitive to nuclear P and T odd processes. Thus EDM becomes the key word not only of New Physics but also of unprecedented fruitful collaboration among particle, atomic. molecular physics. This review intends to help such collaboration over the wide range of physicists.

Fukuyama, Takeshi

2012-01-01

302

The search for a permanent electric dipole moment--still active, still important  

International Nuclear Information System (INIS)

There has been exciting progress in recent years in the search for a permanent electric dipole moment of atoms, molecules, and the neutron. An EDM can exist only if time reversal symmetry is violated. Although such a dipole has not yet been detected, theories of possible new physics, such as Supersymmetry, predict the existence of EDMs within reach of modern experiments. In this brief introduction and survey, I discuss current and planned EDM experiments, and summarize what recent results imply about the size of possible T violating (and hence CP violating) interactions among elementary particles

303

Search for low-energy resonance in electron-positron annihilation-in-flight photon spectrum  

International Nuclear Information System (INIS)

Correlated equal energy positron and electron lines have recently been observed in very heavy-ion collisions at energies near the Coulomb barrier. These observations are consistent with the decay of a slowly moving neutral particle or (e+e-) bound state. The origin of the binding is as yet unclear, one possible explanation for the lines deals with the production of new particle or the formation of an exotic bound state. It should then be possible to produce such a particle state in the inverse reaction. i.e., in electron-positron scattering. This hypotheses has prompted a world wide search for resonance structures in the inverse reaction. A search for structure in the low-energy e+ - e- annihilation-in-flight cross section is described. The electrons are obtained by using solid target with low electrons momentum distribution, while the positrons are obtained from radioactive 27Si isotope. The photons emitted from the electron-positron scattering are detected by a pair of detectors placed at an angle determined by the kinematics of the reaction. The two different sets of detectors used were NaI and Ge(Li). On the data obtained an F-test was conducted on a wide energy range with the peak centred on the accepted position of the resonance peak. The F-test at 97% confidence level rejects the possible existence of a resonance peak corresponding to the GSI peaks in the two gamma channel. The resonance peak is assumed to channel. The resonance peak is assumed to be of a Breit-Wigner line shape. The upper limits for the decay width and the lower limits for the lifetime of the resonance are calculated using the Breit-Wigner cross section. Results from the NaI experiment have been published, while the results from the Ge(Li) experiment are given. 18 figs., 10 tabs., 75 refs

304

From yeV to TeV: Search for the Neutron Electric Dipole Moment  

CERN Document Server

The existence of electric dipole moments (EDM) for fundamental particles signals time-reversal symmetry (T) violation accompanied by violation of parity (P); only upper limits have been established to date. Time-reversal violation in turn implies CP violation under the assumption that CPT is a good symmetry. The neutron is an attractive system for an EDM search, both because it is neu- tral and because a neutron EDM would be relatively easier to interpret than the comparable quantity for a nucleus or even an atom. We introduce briefly the key experimental requirements for such search and describe some aspects of the neutron EDM experiment planned for the Spallation Neutron Source at the U.S. Oak Ridge National Laboratory.

Beck, D H; Park, B K

2011-01-01

305

The electric dipole moment of an electron in H-like ions in an electrostatic storage ring  

OpenAIRE

Theoretical studies are presented how the electric dipole moment (EDM) of the electron in H-like ions in electrostatic storage rings can sensitively be determined. With the proposed experiments a new constraint of about $10^{-29}$ e cm for the electron EDM can be established what is by an order of magnitude more restrictive than the existing bounds. Experiments with H-like ions may provide a possibility to distinguish between the electron EDM effect and the effect of P,T vio...

Bondarevskaya, A. A.; Chubukov, D. V.; Andreev, O. Yu; Mistonova, E. A.; Labzowsky, L. N.; Plunien, G.; Liesen, D.; Bosch, F.

2014-01-01

306

Limit on the Electron Electric Dipole Moment in Gadolinium-Iron Garnet  

Science.gov (United States)

A new method for the detection of the electron electric dipole moment (EDM) using a solid is described. The method involves the measurement of a voltage induced across the solid by the alignment of the sample’s magnetic dipoles in an applied magnetic field, H. A first application of the method to GdIG has resulted in a limit on the electron EDM of 5×10-24ecm, which is a factor of 40 below the limit obtained from the only previous solid-state EDM experiment. The result is limited by the imperfect discrimination of an unexpectedly large voltage that is even upon the reversal of the sample magnetization.

Heidenreich, B. J.; Elliott, O. T.; Charney, N. D.; Virgien, K. A.; Bridges, A. W.; McKeon, M. A.; Peck, S. K.; Krause, D., Jr.; Gordon, J. E.; Hunter, L. R.; Lamoreaux, S. K.

2005-12-01

307

Measurement of the electron electric dipole moment using GdIG  

CERN Document Server

A new method for the detection of the electron edm using a solid is described. The method involves the measurement of a voltage induced across the solid by the alignment of the samples magnetic dipoles in an applied magnetic field, H. A first application of the method to GdIG has resulted in a limit on the electron edm of 5E-24 e-cm, which is a factor of 40 below the limit obtained from the only previous solid-state edm experiment. The result is limited by the imperfect discrimination of an unexpectedly large voltage that is even upon the reversal of the sample magnetization.

Heidenreich, B J; Charney, N D; Virgien, K A; Bridges, A W; McKeon, M A; Peck, S K; Krause, D; Gordon, J E; Hunter, L R; Lamoreaux, S K

2005-01-01

308

CP violating electron-nucleon interactions in multi-Higgs doublet and leptoquark models  

International Nuclear Information System (INIS)

CP violating electron-nucleon interactions and the resulting atomic electric dipole moments (EDM) are studied in several models. It is demonstrated that in the standard model these interactions are very small and are well below the experimental upper bounds. In multi-Higgs doublet models, the four-fermi interactions, can be quite large. In some range of parameters, the contribution of these interactions to the atomic EDM can exceed the contribution of the electron EDM. In leptoquark models the contribution from the tensor interaction is always the dominant one. 20 refs

309

Limit on the Electron Electric Dipole Moment in Gadolinium-Iron Garnet  

International Nuclear Information System (INIS)

A new method for the detection of the electron electric dipole moment (EDM) using a solid is described. The method involves the measurement of a voltage induced across the solid by the alignment of the sample's magnetic dipoles in an applied magnetic field, H. A first application of the method to GdIG has resulted in a limit on the electron EDM of 5x10-24e cm, which is a factor of 40 below the limit obtained from the only previous solid-state EDM experiment. The result is limited by the imperfect discrimination of an unexpectedly large voltage that is even upon the reversal of the sample magnetization

310

CP violating electron-nucleon interactions in multi-Higgs doublet and leptoquark models  

International Nuclear Information System (INIS)

CP violating electron-nucleon interactions and the resulting atomic EDM are studied in several models. In the standard model these interactions are very small and are well below the experimental upper bounds. In multi-Higgs doublet models. The four-Fermi interactions, anti NNanti e?5e and anti N?5Nanti ee, can be quite large. In some range of parameters the contribution of these interactions to the atomic EDM can exceed the contribution of the electron EDM. In leptoquark models the contribution from the tensor interaction, anti N???Nanti e????5e, is the dominant one in Hg, Xe and TlF. (orig.)

311

Measurement of the electron electric dipole moment using GdIG  

OpenAIRE

A new method for the detection of the electron edm using a solid is described. The method involves the measurement of a voltage induced across the solid by the alignment of the samples magnetic dipoles in an applied magnetic field, H. A first application of the method to GdIG has resulted in a limit on the electron edm of 5E-24 e-cm, which is a factor of 40 below the limit obtained from the only previous solid-state edm experiment. The result is limited by the imperfect disc...

Heidenreich, B. J.; Elliott, O. T.; Charney, N. D.; Virgien, K. A.; Bridges, A. W.; Mckeon, M. A.; Peck, S. K.; Krause, Jr; Gordon, J. E.; Hunter, L. R.; Lamoreaux, S. K.

2005-01-01

312

Calorimetric electron telescope mission. Search for dark matter and nearby sources  

Science.gov (United States)

We are developing the CALorimetric Electron Telescope, CALET, mission for the Japanese Experiment Module—Exposed Facility, JEM-EF, of the International Space Station, ISS. Major scientific objective is a search for nearby cosmic ray sources and dark matter by carrying out a precise measurement of the electrons in 1 GeV-20 TeV and the gamma-rays in 20 MeV-several TeV. CALET has, moreover, a capability to measure cosmic ray H, He and heavy ions up to 1000 TeV. It will also have a function to monitor the solar activity and the gamma-ray bursts. The phase A study has started on a schedule of the launch in early 2014 by the H-II Transfer Vehicle, HTV, for a 5-year observation.

Torii, Shoji; CALET Collaboration

2011-02-01

313

Impact of guided exploration and enactive exploration on self-regulatory mechanisms and information acquisition through electronic search.  

Science.gov (United States)

Following instruction in basic skills for electronic search, participants who practiced in a guided exploration mode developed stronger self-efficacy and greater satisfaction than those who practiced in a self-guided exploratory mode. Intrinsic motivation was not affected by exploration mode. On 2 post-training tasks, guided exploration participants produced more effective search strategies. expended less effort, made fewer errors, rejected fewer lines of search, and achieved higher performance. Relative lack of support for self-regulatory factors as mediators of exploration mode impacts was attributed to the uninformative feedback from electronic search, which causes most people to remain at a novice level and to require external guidance for development of self-efficacy and skills. Self-guided learning will be more effective on structured tasks with more informative feedback and for individuals with greater expertise on dynamic tasks. PMID:11768056

Debowski, S; Wood, R E; Bandura, A

2001-12-01

314

Optimization of EDM Process Parameters on Titanium Super Alloys Based on the Grey Relational Analysis  

Directory of Open Access Journals (Sweden)

Full Text Available Electrical discharge machining (EDM is a unconventional machining process for the machining of complex shapes and hard materials that are difficult of machining by conventional machining process. In this paper deals with the optimization of EDM process parameters using the grey relational analysis (GRA based on an orthogonal array for the multi response process. The experiments are conducted on Titanium super alloys with copper electrode based on the Taguchi design of experiments L27 orthogonal array by choosing various parameters such as peak current, pulse on time, pulse off time and tool lift time for EDM process to obtain multiple process responses namely Metal removal rate (MRR and Tool Wear Rate (TWR. The combination of Taguchi method with GRA enables to determine the optimal parameters for multiple response process. Gray relational analysis is used to obtain a performance index called gray relational grade to optimize the EDM process with higher MRR and lower TWR and it is clearly found that the performance of the EDM has greatly increased by optimizing the responses the influence of individual machining parameters also investigated by using analysis of variance for the grey relational grade.

J. Laxman, Dr. K. Guru Raj

2014-05-01

315

Search For The Higgs Boson Decaying Into $\\tau$-Leptons In The Di-Electron Channel  

CERN Document Server

The first dedicated search for Higgs bosons decaying into tau pairs with two electrons and 4 neutrinos in the final state is presented. The search is performed with the CMS detector at the LHC based on an integrated luminosity of 4.9 fb$^{-1}$ and 19.7 fb$^{-1}$ at 7 TeV and 8 TeV, respectively. Events with two reconstructed electrons are selected before extensive multivariate analysis techniques are utilized to achieve an optimal background rejection. The $ee$-channel alone excludes $3.2\\times(\\sigma^H_{SM}\\times BR(H\\rightarrow \\tau\\tau))$ for $m_H = 120$ $GeV/c^2$ and $3.7\\times(\\sigma^H_{SM}\\times BR(H\\rightarrow \\tau\\tau))$ for $m_H = 125$ $GeV/c^2$ at 95\\% confidence level. The $ee$-channel is combined into the official CMS $H\\rightarrow \\tau\\tau$ analysis, to find, for the first time, direct evidence for couplings of the new Higgs-like boson to down-type fermions with 3.2$\\sigma$.

Salfeld-Nebgen, Jakob; Schleper, Peter

316

Search for the Higgs boson decaying into ?-leptons in the Di-electron channel  

International Nuclear Information System (INIS)

The first dedicated search for Higgs bosons decaying into tau pairs with two electrons and 4 neutrinos in the final state is presented. The search is performed with the CMS detector at the LHC based on an integrated luminosity of 4.9 fb-1 and 19.7 fb-1 at 7 TeV and 8 TeV, respectively. Events with two reconstructed electrons are selected before extensive multivariate analysis techniques are utilized to achieve an optimal background rejection. The ee-channel alone excludes 3.2 x (?HSM x BR(H???)) for mH=120 GeV/c2 and 3.7 x (?HSM x BR(H???)) for mH=125 GeV/c2 at 95% confidence level. The ee-channel is combined into the official CMS H??? analysis, to find, for the first time, direct evidence for couplings of the new Higgs-like boson to down-type fermions with 3.20?.

317

Search for the Higgs boson decaying into ?-leptons in the Di-electron channel  

Energy Technology Data Exchange (ETDEWEB)

The first dedicated search for Higgs bosons decaying into tau pairs with two electrons and 4 neutrinos in the final state is presented. The search is performed with the CMS detector at the LHC based on an integrated luminosity of 4.9 fb{sup -1} and 19.7 fb{sup -1} at 7 TeV and 8 TeV, respectively. Events with two reconstructed electrons are selected before extensive multivariate analysis techniques are utilized to achieve an optimal background rejection. The ee-channel alone excludes 3.2 x (?{sup H}{sub SM} x BR(H???)) for m{sub H}=120 GeV/c{sup 2} and 3.7 x (?{sup H}{sub SM} x BR(H???)) for m{sub H}=125 GeV/c{sup 2} at 95% confidence level. The ee-channel is combined into the official CMS H??? analysis, to find, for the first time, direct evidence for couplings of the new Higgs-like boson to down-type fermions with 3.20?.

Salfeld-Nebgen, Jakob Maximilian Henry

2014-08-15

318

Order of Magnitude Smaller Limit on the Electric Dipole Moment of the Electron  

CERN Document Server

The Standard Model (SM) of particle physics is known to be incomplete. It fails to explain dark matter, and why matter survived annihilation with antimatter following the Big Bang. Proposed extensions to the SM, such as weak-scale Supersymmetry (SUSY), may explain these phenomena by positing the existence of new particles and new interactions that are not symmetric under the time-reversal (T) transformation. These same theories nearly always predict a small, yet potentially measurable, asymmetric charge distribution directed along the spin ($\\vec{S}$) of the electron, an electric dipole moment (EDM, $\\vec{d_e}=d_e \\vec{S}/(\\hbar/2)$), which is also asymmetric under T. The predicted value of $d_e$ in these SM extensions is typically in the range of $10^{-27}$-$10^{-30}$ $e$ cm, orders of magnitude larger than is predicted by the SM. Here, we report a new search for the electron EDM using the polar molecule thorium monoxide (ThO). Our result, $d_e = (-2.1 \\pm 3.7_\\mathrm{stat} \\pm 2.5_\\mathrm{syst})\\times 10^{-...

Baron, Jacob; DeMille, David; Doyle, John M; Gabrielse, Gerald; Gurevich, Yulia V; Hess, Paul W; Hutzler, Nicholas R; Kirilov, Emil; Kozyryev, Ivan; O'Leary, Brendon R; Panda, Cristian D; Petrik, Elizabeth S; Spaun, Ben; Vutha, Amar C; West, Adam D

2014-01-01

319

[Proceedings of the] International Conference on Educational Data Mining (EDM) (3rd, Pittsburgh, PA, July 11-13, 2010)  

Science.gov (United States)

The Third International Conference on Data Mining (EDM 2010) was held in Pittsburgh, PA, USA. It follows the second conference at the University of Cordoba, Spain, on July 1-3, 2009 and the first edition of the conference held in Montreal in 2008, and a series of workshops within the AAAI, AIED, EC-TEL, ICALT, ITS, and UM conferences. EDM 2011…

Baker, Ryan S. J. d., Ed.; Merceron, Agathe, Ed.; Pavlik, Philip I., Jr., Ed.

2010-01-01

320

Proceedings of the International Conference on Educational Data Mining (EDM) (2nd, Cordoba, Spain, July 1-3, 2009)  

Science.gov (United States)

The Second International Conference on Educational Data Mining (EDM2009) was held at the University of Cordoba, Spain, on July 1-3, 2009. EDM brings together researchers from computer science, education, psychology, psychometrics, and statistics to analyze large data sets to answer educational research questions. The increase in instrumented…

Barnes, Tiffany, Ed.; Desmarais, Michel, Ed.; Romero, Cristobal, Ed.; Ventura, Sebastian, Ed.

2009-01-01

321

Proceedings of the International Conference on Educational Data Mining (EDM) (5th, Chania, Greece, June 19-21, 2012)  

Science.gov (United States)

The 5th International Conference on Educational Data Mining (EDM 2012) is held in picturesque Chania on the beautiful Crete island in Greece, under the auspices of the International Educational Data Mining Society (IEDMS). The EDM 2012 conference is a leading international forum for high quality research that mines large data sets of educational…

International Educational Data Mining Society, 2012

2012-01-01

322

AFM surface imaging of AISI D2 tool steel machined by the EDM process  

International Nuclear Information System (INIS)

The surface morphology, surface roughness and micro-crack of AISI D2 tool steel machined by the electrical discharge machining (EDM) process were analyzed by means of the atomic force microscopy (AFM) technique. Experimental results indicate that the surface texture after EDM is determined by the discharge energy during processing. An excellent machined finish can be obtained by setting the machine parameters at a low pulse energy. The surface roughness and the depth of the micro-cracks were proportional to the power input. Furthermore, the AFM application yielded information about the depth of the micro-cracks is particularly important in the post treatment of AISI D2 tool steel machined by EDM

323

AFM surface imaging of AISI D2 tool steel machined by the EDM process  

Science.gov (United States)

The surface morphology, surface roughness and micro-crack of AISI D2 tool steel machined by the electrical discharge machining (EDM) process were analyzed by means of the atomic force microscopy (AFM) technique. Experimental results indicate that the surface texture after EDM is determined by the discharge energy during processing. An excellent machined finish can be obtained by setting the machine parameters at a low pulse energy. The surface roughness and the depth of the micro-cracks were proportional to the power input. Furthermore, the AFM application yielded information about the depth of the micro-cracks is particularly important in the post treatment of AISI D2 tool steel machined by EDM.

Guu, Y. H.

2005-04-01

324

Cesium magnetometers for the neutron electric dipole moment (nEDM) experiment  

International Nuclear Information System (INIS)

Full text: One of the most important experiments in particle physics is the hunt for an EDM of a neutron. To achieve sensitivities to EDMs of a few times 10-28 e.cm, the magnetic field, including its spatial gradients, has to be precisely measured and controlled. To provide the required sensitivity of magnetic field measurements at the <100fT/?(Hz) level, a system of optically-pumped atomic Cs magnetometers has been developed at Fribourg University. The Cs sensor itself is a spherical, paraffin-coated and evacuated glass cell containing Cs vapour at room temperature. The present magnetometer system consists of 8 vacuum compatible and four vacuum and high voltage compatible sensors. The system is in constant evolution to adapt it to the operating environment of the nEDM experiment at the Paul Scherrer Institut. In this contribution, the current solutions and results of magnetic field measurements will be presented. (author)

325

?EDM-produced mechanical grippers for handling and assembly in microtechnology  

Science.gov (United States)

Two mechanical gripper types have been designed. Using a technology selection method, EDM was selected as the most appropriate fabrication technology for the designed grippers. Prototypes have been fabricated by wire EDM on a conventional machine. Increased attention has been paid to methodology of the production process and exploration of (mu) -EDM possibilities. The tolerance obtained is about 1 micrometers . The accuracy of the machined product is mainly determined by the quality of the electrode, its handling and the adjustment procedures. After fabrication the grippers were integrated onto a station for handling and assembly of microstructures. This paper provides a description of the used methodology in the production sequence and information on the machining process of the whole gripping system (gripper, holder, arrow). The results after the production are tested, analyzed and discussed.

Petrovic, Dragan; Popovic, Gordana; Chatzitheodoridis, Elias; Del Medico, Oscar; Almansa, Ana; Suemecz, Franz; Herbst, Peter; Brenner, Werner; Detter, Helmut; Duffait, Roland

2001-11-01

326

A new electrode wear compensation method for improving performance in 3D micro EDM milling  

International Nuclear Information System (INIS)

As one of the non-traditional manufacturing processes, micro electrical discharge machining (EDM) has been widely applied for manufacturing precise and complex microstructures. However, a number of issues remain to be studied before micro EDM can become a reliable processing method. Efforts to get higher machining quality and to improve efficiency have been carried out. The electrode wear compensation method is one of the key factors in micro EDM milling. This paper proposes a new electrode wear compensation method, the combination of the linear compensation method (LCM) and the uniform wear method (UWM), called the CLU method. This approach combines LCM, UWM and the theoretical model. Experimental results indicate that machining performance such as material removal rate, electrode wear ratio and surface roughness using the proposed method has been improved compared to that by the uniform wear method.

327

Extension of the search region of pair densities by means of the scaling of the electron coordinates  

International Nuclear Information System (INIS)

We present a scheme for correcting the pair density (PD) to get it close to the ground state one. The search region of PDs is efficiently extended by adding the uniformly-scaled PDs to its elements. The key point is that the search region of PDs is kept within the set of N-representable PDs. The validity of this scheme is confirmed by numerical calculations of neutral neon atom. It is shown that the root-mean-square error of the electron-electron interaction and external potential energies, which can be a benchmark for the error of the PD, is reduced to about two-third without additional heavy calculations.

328

Interim results from the characterization testing of the Engineering Development (EDM) rubidium clocks for satellite applications  

Science.gov (United States)

Some interim results from the environmental testing program to evaluate the Engineering Design Model (EDM) of the EG and G Spaceborne Rubidium Clock are presented. This effort is in support of the Global Positioning System (GPS) BLOCK IIR program and is intended to characterize the performance of EG and G design for BLOCK IIR satellite applications. Two EG and G EDM units are currently under test at NRL's Clock Test Facility to measure the long-term frequency stability, drift, and frequency versus temperature characteristics.

Powers, Edward D., Jr.; Danzy, Fredrick

1990-01-01

329

Avaliação da geração de microtrincas do aço rápido ABNT M2 no processo EDM com adição de SiC = Evaluation of microcrack formation of ABNT M2 high speed steel in the EDM process, with addition of silicon carbide powder  

Directory of Open Access Journals (Sweden)

Full Text Available É sabido que a Usinagem por Descargas Elétricas (EDM é um processo térmico em que pode haver temperaturas muito elevadas (superiores a 1.200°C na região de usinagem. Consequentemente é fácil de entender o fato de as peças usinadas por EDM apresentarem camadas superficiais endurecidas, refundidas e com elevado número de microtrincas superficiais. A formação de microtrincas está associada com o desenvolvimento de altas tensões térmicas que excedem a tensão máxima de resistência do material. Além disso, as microtrincas superficiais penetram em profundidade com extensões que dependem da energia de descarga. O trabalho proposto tem por objetivo estudar o efeito da adição de pó de SiC em vários fluidos dielétricos, sobre a geração de microtrincas superficiais, no aço rápido ABNT M2, durante a usinagem por descargas elétricas. Os resultados apresentados mostramredução da quantidade de microtrincas nas superfícies usinadas, quando se adiciona pó de SiC ao dielétrico, quando comparadas com as usinadas com EDM convencional.It is known that Electrical Discharge Machining (EDM is a thermal process in which extremely high temperatures (in excess of 1200°C can occur in the machining area. Consequently, it is easy tounderstand that during each electric discharge, high temperatures are generated, causing local fusion or even evaporation of the machined material. In each discharge, a crater is formed in the material and a small crater is formed in the electrode. Of every meltedmaterial produced in each discharge, only 15% or less is removed using dielectric fluid. The remaining melted material solidifies, forming a wrinkled surface. The characteristics of theobtained surface – overlap of craters, globules of sullage, chimneys, bubbles (formed when the gases arrested are liberated through the resolidified material – are revealed through an analysis using a scanning electron microscope. The proposed work has as its objective to study the effect of the addition of SiC powder into several dielectric fluids, on microcrack formation of high-speed steel (ABNT M2, during electrical discharge machining. The results show that the samples machined with the addition of SiC powders presentedsignificant reduction in the number of microcracks in the machined surface, when compared with those machined with conventional EDM.

Jean Robert Pereira Rodrigues

2008-07-01

330

Relationship of Surface Roughness with Current and Voltage During Wire EDM  

Directory of Open Access Journals (Sweden)

Full Text Available Wire EDM is in use for a long time for cutting punches and dies, shaped pockets and other machine parts. Surface finish of the machined surface mainly depends on current and voltage used during machining. In the present research experimental investigations have been conducted to establish relationships of job surface finish with current and voltage. Brass wires of diameters 0.3, 0.25, 0.20 and 0.15 mm were used. Work materials tested were mild steel, aluminum, cemented carbide, copper and stainless steel. After machining each material with specific current and voltage the hardness and the job surface roughness were measured and their surfaces were observed under an electron-scanning microscope. Results of the experiments show that in general the machined surface becomes rougher with increase in current and voltage. Microstructures of the specimens also show that craters on the finished surface become larger as a result of using higher current and voltage. It was also found that wires of smaller diameters give smoother surface than those cut with larger diameters. It has been established that machining of carbides should be limited to wires with diameter equal to or less than 0.15 mm. Use of wires of greater diameters causes frequent wire breakage. A statistical analysis was done to pick up the most probabilistic data from the bank of data obtained from the experiments. Finally, mathematical relationships have been developed between job surface finish with current and voltage within the specified ranges for a few work materials.

Ahsan Ali Khan

2006-01-01

331

Demonstration of Surface Electron Rejection with Interleaved Germanium Detectors for Dark Matter Search  

CERN Document Server

SuperCDMS, a direct search for WIMPs, is currently operating a 9-kg array of cryogenic germanium (Ge) detectors in the Soudan Underground Laboratory. These detectors, known as iZIPs, use ionization and phonon sensors placed symmetrically on both sides of a Ge crystal to measure both charge and athermal phonons from each particle interaction. The information from each event provides excellent discrimination between electron recoils and nuclear recoils, as well as discrimination between events on the detector surface and those in the interior. To demonstrate the surface electron rejection capabilities, two $^{210}$Pb sources were installed facing detectors, producing $\\sim$130 beta decays/hr. In $\\sim$800 live hours, no events leaked into the WIMP signal region in the recoil energy range 8--115 keVr, providing an upper limit to the surface event leakage fraction of $1.7 \\times 10^{-5}$ at 90% C.L. This rejection factor demonstrates that surface electrons would produce $< 0.6$ event background in the 0.3 ton-...

Agnese, R; Balakishiyeva, D; Thakur, R Basu; Bauer, D A; Borgland, A; Brandt, D; Brink, P L; Bunker, R; Cabrera, B; Caldwell, D O; Cerdeno, D G; Chagani, H; Cherry, M; Cooley, J; Cornell, B; Crewdson, C H; Cushman, P; Daal, M; Di Stefano, P C F; Silva, E Do Couto E; Doughty, T; Esteban, L; Fallows, S; Figueroa-Feliciano, E; Fox, J; Fritts, M; Godfrey, G L; Golwala, S R; Hall, J; Harris, H R; Hasi, J; Hertel, S A; Hines, B A; Hofer, T; Holmgren, D; Hsu, L; Huber, M E; Jastram, A; Kamaev, O; Kara, B; Kelsey, M H; Kenany, S A; Kennedy, A; Kenney, C J; Kiveni, M; Koch, K; Loer, B; Asamar, E Lopez; Mahapatra, R; Mandic, V; Martinez, C; McCarthy, K A; Mirabolfathi, N; Moffatt, R A; Moore, D C; Nadeau, P; Nelson, R H; Novak, L; Page, K; Partridge, R; Pepin, M; Phipps, A; Prasad, K; Pyle, M; Qiu, H; Radpour, R; Rau, W; Redl, P; Reisetter, A; Resch, R W; Ricci, Y; Saab, T; Sadoulet, B; Sander, J; Schmitt, R; Schneck, K; Schnee, R W; Scorza, S; Seitz, D; Serfass, B; Shank, B; Speller, D; Tomada, A; Villano, A N; Welliver, B; Wright, D H; Yellin, S; Yen, J J; Young, B A; Zhang, J

2013-01-01

332

Demonstration of surface electron rejection with interleaved germanium detectors for dark matter searches  

Energy Technology Data Exchange (ETDEWEB)

The SuperCDMS experiment in the Soudan Underground Laboratory searches for dark matter with a 9-kg array of cryogenic germanium detectors. Symmetric sensors on opposite sides measure both charge and phonons from each particle interaction, providing excellent discrimination between electron and nuclear recoils, and between surface and interior events. Surface event rejection capabilities were tested with two {sup 210}Pb sources producing ?130 beta decays/hr. In ?800 live hours, no events leaked into the 8–115 keV signal region, giving upper limit leakage fraction 1.7 × 10{sup ?5} at 90% C.L., corresponding to < 0.6 surface event background in the future 200-kg SuperCDMS SNOLAB experiment.

Agnese, R.; Balakishiyeva, D.; Saab, T.; Welliver, B. [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States); Anderson, A. J.; Figueroa-Feliciano, E.; Hertel, S. A.; McCarthy, K. A. [Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Basu Thakur, R. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illnois 61801 (United States); Bauer, D. A.; Holmgren, D.; Hsu, L.; Loer, B.; Schmitt, R. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Borgland, A.; Brandt, D.; Brink, P. L.; Do Couto E Silva, E.; Godfrey, G. L.; Hasi, J. [SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Collaboration: The SuperCDMS Collaboration; and others

2013-10-14

333

Demonstration of surface electron rejection with interleaved germanium detectors for dark matter searches  

International Nuclear Information System (INIS)

The SuperCDMS experiment in the Soudan Underground Laboratory searches for dark matter with a 9-kg array of cryogenic germanium detectors. Symmetric sensors on opposite sides measure both charge and phonons from each particle interaction, providing excellent discrimination between electron and nuclear recoils, and between surface and interior events. Surface event rejection capabilities were tested with two 210Pb sources producing ?130 beta decays/hr. In ?800 live hours, no events leaked into the 8–115 keV signal region, giving upper limit leakage fraction 1.7 × 10?5 at 90% C.L., corresponding to < 0.6 surface event background in the future 200-kg SuperCDMS SNOLAB experiment

334

Search for W' bosons decaying to an electron and a neutrino with the D0 detector  

CERN Document Server

This Letter describes the search for a new heavy charged gauge boson W' decaying into an electron and a neutrino. The data were collected with the D0 detector at the Fermilab Tevatron proton-antiproton Collider at a center-of-mass energy of 1.96 TeV, and correspond to an integrated luminosity of about 1 inverse femtobarn. Lacking any significant excess in the data in comparison with known processes, an upper limit is set on the production cross section times branching fraction, and a W' boson with mass below 1.00 TeV can be excluded at the 95% C.L., assuming standard-model-like couplings to fermions. This result significantly improves upon previous limits, and is the most stringent to date.

Abazov, V; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguiló, E; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Ancu, L S; Andeen, T; Anderson, S; Andrieu, B; Anzelc, M S; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; Åsman, B; Assis-Jesus, A C S; Atramentov, O; Autermann, C; Avila, C; Ay, C; Badaud, F; Baden, A; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Banerjee, P; Barberis, E; Barfuss, A F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benítez, J A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Biscarat, C; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Bloom, K; Böhnlein, A; Boline, D; Bolton, T A; Borissov, G; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Buchanan, N J; Buchholz, D; Bühler, M; Büscher, V; Bunichev, S; Burdin, S; Burke, S; Burnett, T H; Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Carvalho, W; Casey, B C K; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chan, K; Chandra, A; Charles, F; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Cihangir, S; Claes, D; Coadou, Y; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M C; Crepe-Renaudin, S; Cutts, D; Cwiok, M; Da Motta, H; Das, A; Davies, G; De, K; De Jong, S J; De La Cruz-Burelo, E; De Oliveira Martins, C; Degenhardt, J D; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dong, H; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Ford, M; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; García, C; García-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Gelé, D; Gerber, C E; Gershtein, Yu; Gillberg, D; Ginther, G; Gollub, N; Gómez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, P; Grivaz, J F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, J; Guo, F; Gutíerrez, P; Gutíerrez, G; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Hanagaki, K; Hansson, P; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hong, S J; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jesik, R; Johns, K; Johnson, C; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Käfer, D; Kajfasz, E; Kalinin, A M; Kalk, J R; Kalk, J M; Kappler, S; Karmanov, D; Kasper, P; Katsanos, I; Kau, D; Kaur, R; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Yu M; Khatidze, D; Kim, H; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J P; Kopal, M; Korablev, V M; Kozelov, A V; Krop, D; Kühl, T; Kumar, A; Kunori, S; Kupco, A; Kurca, T; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G; Lebrun, P; Lee, W M; Leflat, A; Lehner, F; Lellouch, J; Lévêque, J; Lewis, P; Li, J; Li, Q Z; Li, L; Lietti, S M; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobo, L; Lobodenko, A; Lokajícek, M; Love, P; Lubatti, H J; Lyon, A L; Maciel, A K A; Mackin, D; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martin, B; McCarthy, R; Melnitchouk, A; Mendes, A; Mendoza, L; Mercadante, P G; Merkin, M; Merritt, K W; Meyer, J; Meyer, A; Millet, T; Mitrevski, J; Molina, J; Mommsen, R K; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulders, M; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nogima, H; Nomerotski, A; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Ochando, C; Onoprienko, D; Oshima, N; Osta, J; Otec, R; Oteroy-Garzon, G J; Owen, M; Padley, P; Pangilinan, M; Parashar, N; Park, S J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Penning, B; Perfilov, M; Peters, K; Peters, Y; Petroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M E; Polozov, P; Pope, B G; Popov, A V; Potter, C; Prado da Silva, W L; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Ranjan, K

2007-01-01

335

Search for W' bosons decaying to an electron and a neutrino with the D0 detector.  

Science.gov (United States)

This Letter describes the search for a new heavy charged gauge boson W' decaying into an electron and a neutrino. The data were collected with the D0 detector at the Fermilab Tevatron pp[over] Collider at sqrt[s]=1.96 TeV, and correspond to an integrated luminosity of about 1 fb(-1). Lacking any significant excess in the data in comparison with known processes, an upper limit is set on sigma_(W') x B(W')-->e nu), and a W' boson with mass below 1.00 TeV can be excluded at the 95% C.L., assuming standard-model-like couplings to fermions. This result significantly improves upon previous limits and is the most stringent to date. PMID:18232966

Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguilo, E; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Ancu, L S; Andeen, T; Anderson, S; Andrieu, B; Anzelc, M S; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; Asman, B; Assis Jesus, A C S; Atramentov, O; Autermann, C; Avila, C; Ay, C; Badaud, F; Baden, A; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Banerjee, P; Barberis, E; Barfuss, A-F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benitez, J A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Biscarat, C; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Borissov, G; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Buchanan, N J; Buchholz, D; Buehler, M; Buescher, V; Bunichev, S; Burdin, S; Burke, S; Burnett, T H; Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Carvalho, W; Casey, B C K; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chan, K; Chandra, A; Charles, F; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Cihangir, S; Claes, D; Coadou, Y; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Crépé-Renaudin, S; Cutts, D; Cwiok, M; da Motta, H; Das, A; Davies, G; De, K; de Jong, S J; De La Cruz-Burelo, E; De Oliveira Martins, C; Degenhardt, J D; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dong, H; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Ford, M; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; Garcia, C; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Gelé, D; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Gollub, N; Gómez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, J; Guo, F; Gutierrez, P; Gutierrez, G; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Hanagaki, K; Hansson, P; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hong, S J; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jesik, R; Johns, K; Johnson, C; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Käfer, D; Kajfasz, E; Kalinin, A M; Kalk, J R; Kalk, J M; Kappler, S; Karmanov, D; Kasper, P; Katsanos, I; Kau, D; Kaur, R; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y M; Khatidze, D; Kim, H; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J-P; Kopal, M; Korablev, V M; Kozelov, A V; Krop, D; Kuhl, T; Kumar, A; Kunori, S; Kupco, A; Kurca, T; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G; Lebrun, P; Lee, W M; Leflat, A; Lehner, F; Lellouch, J; Leveque, J; Lewis, P; Li, J; Li, Q Z; Li, L; Lietti, S M; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobo, L; Lobodenko, A; Lokajicek, M; Love, P; Lubatti, H J; Lyon, A L; Maciel, A K A; Mackin, D; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martin, B; McCarthy, R; Melnitchouk, A; Mendes, A; Mendoza, L; Mercadante, P G; Merkin, M; Merritt, K W; Meyer, J; Meyer, A; Millet, T; Mitrevski, J; Molina, J; Mommsen, R K; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulders, M; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nogima, H; Nomerotski, A; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Ochando, C; Onoprienko, D; Oshima, N; Osta, J; Otec, R; Otero y Garzón, G J; Owen, M; Padley, P; Pangilinan, M; Parashar, N; Park, S-J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Penning, B; Perfilov, M; Peters, K; Peters, Y; Pétroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M-E; Polozov, P; Pope, B G; Popov, A V; Potter, C; Prado da Silva, W L; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S

2008-01-25

336

The Electronics and Data Acquisition System of the DarkSide Dark Matter Search  

CERN Document Server

It is generally inferred from astronomical measurements that Dark Matter (DM) comprises approximately 27\\% of the energy-density of the universe. If DM is a subatomic particle, a possible candidate is a Weakly Interacting Massive Particle (WIMP), and the DarkSide-50 (DS) experiment is a direct search for evidence of WIMP-nuclear collisions. DS is located underground at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy, and consists of three active, embedded components; an outer water veto (CTF), a liquid scintillator veto (LSV), and a liquid argon (LAr) time projection chamber (TPC). This paper describes the data acquisition and electronic systems of the DS detectors, designed to detect the residual ionization from such collisions.

Alexander, T; Arisaka, K; Back, H O; Baldin, B; Biery, K; Bonfini, G; Bossa, M; Brigatti, A; Brodsky, J; Budano, F; Cadonati, L; Calaprice, F; Canci, N; Candela, A; Cao, H; Cariello, M; Cavalcante, P; Chavarria, A; Chepurnov, A; Cocco, A G; Crippa, L; D'Angelo, D; D'Incecco, M; Davini, S; De Deo, M; Derbin, A; Devoto, A; Di Eusanio, F; Di Pieto, G; Edkins, E; Empl, A; Fan, A; Fiorillo, G; Fomenko, K; Forster, G; Franco, D; Gabriele, F; Galbiati, C; Goretti, A; Grandi, L; Gromov, M; Guan, M Y; Guardincerri, Y; Hackett, B; Herner, K; Hungerford, E; Ianni, Al; Ianni, An; Jollet, C; Keeter, K; Kendziora, C; Kidner, S; Kobychev, V; Koh, G; Korablev, D; Korga, G; Kurlej, A; Li, P X; Loer, B; Lombardi, P; Love, C; Ludhova, L; Luitz, S; Ma, Y Q; Machulin, I; Mandarano, A; Mari, S M; Maricic, J; Marini, L; Martoff, J; Meregaglia, A; Meroni, E; Meyers, P D; Milincic, R; Montanari, D; Montuschi, M; Monzani, M E; Mosteiro, P; Mount, B; Muratova, V; Musico, P; Nelson, A; Odrowski, S; Okounkoa, M; Orsini, M; Ortica, F; Pagani, L; Pallavicini, M; Pantic, E; Papp, L; Parmeggiano, S; Parsells, Bob; Pelczar, K; Pelliccia, N; Perasso, S; Pocar, A; Pordes, S; Pugachev, D; Qian, H; Randle, K; Ranucci, G; Razeto, A; Reinhold, B; Renshaw, A; Romani, A; Rossi, B; Rossi, N; Rountree, S D; Sablone, D; Saggese, P; Saldanha, R; Sands, W; Sangiorgio, S; Segreto, E; Semenov, D; Shields, E; Skorokhvatov, M; Smirnov, O; Sotnikov, A; Stanford, C; Suvorov,; Tartaglia, R; Tatarowicz, J; Testera, G; Tonazzo, A; Unzhakov, E; Vogelaar, R B; Wada, M; Walker, S E; Wang, H; Wang, Y; Watson, A; Westerdale, S; Wojcik, M; Wright, A; Xiang, X; Xu, J; Yang, C G; Yoo, J; Zavatarelli, S; Zec, A; Zhu, C; Zuzel, G

2014-01-01

337

MiniBooNE: first results on the muon-to-electron neutrino oscillation search  

Energy Technology Data Exchange (ETDEWEB)

MiniBooNE's first results on a search for an electron neutrino excess in a muon neutrino beam are presented, together with an analysis of the data within a two neutrino {nu}{sub {mu}} {yields} {nu}{sub e} appearance-only oscillation context. MiniBooNE finds excellent agreement between data and Standard Model predictions in the oscillation analysis energy region. If neutrino and antineutrino oscillations are the same, MiniBooNE excludes at {approx} 98% confidence level the two neutrino {nu}{sub {mu}} {yields} {nu}{sub e} appearance-only oscillation interpretation of the LSND anomaly. MiniBooNE also finds a discrepancy at energies below the oscillation analysis range, which is currently not understood and under investigation.

Sorel, M.; /Columbia U.

2007-10-01

338

Search for displaced supersymmetry in events with an electron and a muon with large impact parameters.  

Science.gov (United States)

A search for new long-lived particles decaying to leptons is presented using proton-proton collisions produced by the LHC at sqrt[s]=8??TeV. Data used for the analysis were collected by the CMS detector and correspond to an integrated luminosity of 19.7??fb^{-1}. Events are selected with an electron and muon with opposite charges that both have transverse impact parameter values between 0.02 and 2 cm. The search has been designed to be sensitive to a wide range of models with nonprompt e-? final states. Limits are set on the "displaced supersymmetry" model, with pair production of top squarks decaying into an e-? final state via R-parity-violating interactions. The results are the most restrictive to date on this model, with the most stringent limit being obtained for a top squark lifetime corresponding to c?=2??cm, excluding masses below 790 GeV at 95% confidence level. PMID:25723204

Khachatryan, V; Sirunyan, A M; Tumasyan, A; Adam, W; Bergauer, T; Dragicevic, M; Erö, J; Friedl, M; Frühwirth, R; Ghete, V M; Hartl, C; Hörmann, N; Hrubec, J; Jeitler, M; Kiesenhofer, W; Knünz, V; Krammer, M; Krätschmer, I; Liko, D; Mikulec, I; Rabady, D; Rahbaran, B; Rohringer, H; Schöfbeck, R; Strauss, J; Taurok, A; Treberer-Treberspurg, W; Waltenberger, W; Wulz, C-E; Mossolov, V; Shumeiko, N; Suarez Gonzalez, J; Alderweireldt, S; Bansal, M; Bansal, S; Cornelis, T; De Wolf, E A; Janssen, X; Knutsson, A; Luyckx, S; Ochesanu, S; Rougny, R; Van De Klundert, M; Van Haevermaet, H; Van Mechelen, P; Van Remortel, N; Van Spilbeeck, A; Blekman, F; Blyweert, S; D'Hondt, J; Daci, N; Heracleous, N; Keaveney, J; Lowette, S; Maes, M; Olbrechts, A; Python, Q; Strom, D; Tavernier, S; Van Doninck, W; Van Mulders, P; Van Onsem, G P; Villella, I; Caillol, C; Clerbaux, B; De Lentdecker, G; Dobur, D; Favart, L; Gay, A P R; Grebenyuk, A; Léonard, A; Mohammadi, A; Perniè, L; Reis, T; Seva, T; Thomas, L; Vander Velde, C; Vanlaer, P; Wang, J; Zenoni, F; Adler, V; Beernaert, K; Benucci, L; Cimmino, A; Costantini, S; Crucy, S; Dildick, S; Fagot, A; Garcia, G; Mccartin, J; Ocampo Rios, A A; Ryckbosch, D; Salva Diblen, S; Sigamani, M; Strobbe, N; Thyssen, F; Tytgat, M; Yazgan, E; Zaganidis, N; Basegmez, S; Beluffi, C; Bruno, G; Castello, R; Caudron, A; Ceard, L; Da Silveira, G G; Delaere, C; du Pree, T; Favart, D; Forthomme, L; Giammanco, A; Hollar, J; Jafari, A; Jez, P; Komm, M; Lemaitre, V; Nuttens, C; Pagano, D; Perrini, L; Pin, A; Piotrzkowski, K; Popov, A; Quertenmont, L; Selvaggi, M; Vidal Marono, M; Vizan Garcia, J M; Beliy, N; Caebergs, T; Daubie, E; Hammad, G H; Aldá Júnior, W L; Alves, G A; Brito, L; Correa Martins Junior, M; Dos Reis Martins, T; Mora Herrera, C; Pol, M E; Carvalho, W; Chinellato, J; Custódio, A; Da Costa, E M; De Jesus Damiao, D; De Oliveira Martins, C; Fonseca De Souza, S; Malbouisson, H; Matos Figueiredo, D; Mundim, L; Nogima, H; Prado Da Silva, W L; Santaolalla, J; Santoro, A; Sznajder, A; Tonelli Manganote, E J; Vilela Pereira, A; Bernardes, C A; Dogra, S; Fernandez Perez Tomei, T R; Gregores, E M; Mercadante, P G; Novaes, S F; Padula, Sandra S; Aleksandrov, A; Genchev, V; Iaydjiev, P; Marinov, A; Piperov, S; Rodozov, M; Stoykova, S; Sultanov, G; Vutova, M; Dimitrov, A; Glushkov, I; Hadjiiska, R; Kozhuharov, V; Litov, L; Pavlov, B; Petkov, P; Bian, J G; Chen, G M; Chen, H S; Chen, M; Du, R; Jiang, C H; Plestina, R; Romeo, F; Tao, J; Wang, Z; Asawatangtrakuldee, C; Ban, Y; Liu, S; Mao, Y; Qian, S J; Wang, D; Zhang, L; Zou, W; Avila, C; Chaparro Sierra, L F; Florez, C; Gomez, J P; Gomez Moreno, B; Sanabria, J C; Godinovic, N; Lelas, D; Polic, D; Puljak, I; Antunovic, Z; Kovac, M; Brigljevic, V; Kadija, K; Luetic, J; Mekterovic, D; Sudic, L; Attikis, A; Mavromanolakis, G; Mousa, J; Nicolaou, C; Ptochos, F; Razis, P A; Bodlak, M; Finger, M; Finger, M; Assran, Y; Ellithi Kamel, A; Mahmoud, M A; Radi, A; Kadastik, M; Murumaa, M; Raidal, M; Tiko, A; Eerola, P; Fedi, G; Voutilainen, M; Härkönen, J; Karimäki, V; Kinnunen, R; Kortelainen, M J; Lampén, T; Lassila-Perini, K; Lehti, S; Lindén, T; Luukka, P; Mäenpää, T; Peltola, T; Tuominen, E; Tuominiemi, J; Tuovinen, E; Wendland, L; Talvitie, J; Tuuva, T; Besancon, M; Couderc, F; Dejardin, M; Denegri, D; Fabbro, B; Faure, J L; Favaro, C; Ferri, F; Ganjour, S; Givernaud, A; Gras, P; Hamel de Monchenault, G; Jarry, P; Locci, E; Malcles, J; Rander, J; Rosowsky, A; Titov, M; Baffioni, S; Beaudette, F; Busson, P; Charlot, C; Dahms, T; Dalchenko, M; Dobrzynski, L; Filipovic, N; Florent, A; Granier de Cassagnac, R; Mastrolorenzo, L; Miné, P; Mironov, C; Naranjo, I N; Nguyen, M; Ochando, C; Paganini, P; Regnard, S; Salerno, R; Sauvan, J B; Sirois, Y; Veelken, C; Yilmaz, Y; Zabi, A; Agram, J-L; Andrea, J; Aubin, A; Bloch, D; Brom, J-M; Chabert, E C; Collard, C; Conte, E; Fontaine, J-C; Gelé, D; Goerlach, U; Goetzmann, C; Le Bihan, A-C; Van Hove, P; Gadrat, S; Beauceron, S; Beaupere, N; Boudoul, G; Bouvier, E; Brochet, S; Carrillo Montoya, C A; Chasserat, J; Chierici, R; Contardo, D; Depasse, P; El Mamouni, H; Fan, J; Fay, J; Gascon, S; Gouzevitch, M; Ille, B; Kurca, T; Lethuillier, M; Mirabito, L; Perries, S; Ruiz Alvarez, J D; Sabes, D; Sgandurra, L; Sordini, V; Vander Donckt, M; Verdier, P; Viret, S; Xiao, H; Tsamalaidze, Z; Autermann, C; Beranek, S; Bontenackels, M; Edelhoff, M; Feld, L; Hindrichs, O; Klein, K; Ostapchuk, A; Perieanu, A; Raupach, F; Sammet, J; Schael, S; Weber, H; Wittmer, B; Zhukov, V; Ata, M; Brodski, M; Dietz-Laursonn, E; Duchardt, D; Erdmann, M; Fischer, R; Güth, A; Hebbeker, T; Heidemann, C; Hoepfner, K; Klingebiel, D; Knutzen, S; Kreuzer, P; Merschmeyer, M; Meyer, A; Millet, P; Olschewski, M; Padeken, K; Papacz, P; Reithler, H; Schmitz, S A; Sonnenschein, L

2015-02-13

339

On Measuring the Electron Electric Dipole Moment in Trapped Molecular Ions  

CERN Document Server

Trapped diatomic molecular ions could prove to be a sensitive probe for a permanent electron electric dipole moment (eEDM). We propose to use a ground or metastable $^3\\Delta_1$ level, due to its high polarizability and large EDM enhancement factor. Ions allow for simple trapping and long interrogation times, but require a time-varying electric bias field in order to probe the eEDM. We discuss experimental design as well as challenges in performing a precision spectroscopic measurement in rapidly time-varying electric fields.

Leanhardt, Aaron E; Loh, Huanqian; Maletinsky, Patrick; Meyer, Edmund R; Sinclair, Laura C; Stutz, Russell P; Cornell, Eric A

2010-01-01

340

Analysis of aerosol emission and hazard evaluation of electrical discharge machining (EDM) process.  

Science.gov (United States)

The safety and environmental aspects of a manufacturing process are important due to increased environmental regulations and life quality. In this paper, the concentration of aerosols in the breathing zone of the operator of Electrical Discharge Machining (EDM), a commonly used non traditional manufacturing process is presented. The pattern of aerosol emissions from this process with varying process parameters such as peak current, pulse duration, dielectric flushing pressure and the level of dielectric was evaluated. Further, the HAZOP technique was employed to identify the inherent safety aspects and fire risk of the EDM process under different working conditions. The analysis of aerosol exposure showed that the concentration of aerosol was increased with increase in the peak current, pulse duration and dielectric level and was decreased with increase in the flushing pressure. It was also found that at higher values of peak current (7A) and pulse duration (520 micros), the concentration of aerosols at breathing zone of the operator was above the permissible exposure limit value for respirable particulates (5 mg/m(3)). HAZOP study of the EDM process showed that this process is vulnerable to fire and explosion hazards. A detailed discussion on preventing the fire and explosion hazard is presented in this paper. The emission and risk of fire of the EDM process can be minimized by selecting proper process parameters and employing appropriate control strategy. PMID:20720340

Jose, Mathew; Sivapirakasam, S P; Surianarayanan, M

2010-01-01

341

OPTIMIZATION OF OPERATING PARAMETERS FOR EDM PROCESS BASED ON THE TAGUCHI METHOD AND ARTIFICIAL NEURAL NETWORK  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper the complexity of electrical discharge machining process which is very difficult to determine optimal cutting parameters for improving cutting performance has been reported. Optimization of operating parameters is an important step in machining, particularly for operating unconventional machiningprocedure like EDM. A suitable selection of machining parameters for the electrical discharge machining process relies heavily on the operators’ technologies and experience because of their numerous and diverse range. Machining parameters tables provided by the machine tool builder can not meet the operators’ requirements, since for anarbitrary desired machining time for a particular job, they do not provide the optimal machining conditions. An approach to determine parameters setting is proposed. Based on the Taguchi parameter design method and the analysis of variance, the significant factors affecting the machining performance such as total machining time, oversize and taper for a hole machined by EDM process, are determined.Artificial neural networks are highly flexible modeling tools with an ability to learn the mapping between input variables and output feature spaces. The superiority of using artificial neural networks inmodeling machining processes make easier to model the EDM process with dimensional input and output spaces. On the basis of the developed neural network model, for a required total machining time, oversize and taper the corresponding process parameters to be set in EDM by using the developed and trained ANN are determined.

A.Thillaivanan,

2010-12-01

342

Optimization Of Edm Parameters Using Taguchi Method And Grey Relational Analysis For Mild Steel Is 2026  

Directory of Open Access Journals (Sweden)

Full Text Available Optimization is one of the techniques used in manufacturing sectors to arrive for the best manufacturing conditions, which is an essential need for industries towards manufacturing of quality products at lower cost. This paper aims to investigate the optimal set of process parameters such as current, pulse ON and OFF time in Electrical Discharge Machining (EDM process to identify the variations in three performance characteristics such as rate of material removal, wear rate on tool, and surface roughness value on the work material for machining Mild Steel IS 2026 using copper electrode. Based on the experiments conducted on L9 orthogonal array, analysis has been carried out using Grey Relational Analysis, a Taguchi method. Response tables and graphs were used to find the optimal levels of parameters in EDM process. The confirmation experiments were carried out to validate the optimal results. Thus, the machining parameters for EDM were optimized for achieving the combined objectives of higher rate of material removal, lower wear rate on tool, and lower surface roughness value on the work material considered in this work. The obtained results show that the Taguchi Grey relational Analysis is being effective technique to optimize the machining parameters for EDM process.

RAGHURAMAN S, THIRUPPATHI K, PANNEERSELVAM T, SANTOSH S

2013-07-01

343

Traveling wire electrode increases productivity of Electrical Discharge Machining /EDM/ equipment  

Science.gov (United States)

Traveling wire electrode on electrical discharge machining /EDM/ equipment reduces the time requirements for precision cutting. This device enables cutting with a minimum of lost material and without inducing stress beyond that inherent in the material. The use of wire increases accuracy and enables tighter tolerances to be maintained.

Kotora, J., Jr.; Smith, S. V.

1967-01-01

344

Surface characteristics and damage of monocrystalline silicon induced by wire-EDM  

Science.gov (United States)

Wire-EDM has recently shown itself as an alternative approach for slicing silicon and other semiconductor materials without the presence of significant chipping as normally found in the traditional machining processes. However, the intensive electrical spark between a wire electrode and silicon can cause damage to the cut surface and subsurface in micro and nano-scale aspects. This paper presents the influence of major process parameters on the cut surface characteristics and damage in the wire-EDMing of silicon. An n-type monocrystalline silicon wafer was cut under different spark energy densities, duty cycles and dielectric flushing rates. Poor cut surface quality and high amount of electrode material deposition were obtained when low spark energy density, small duty cycle and low dielectric flushing rate were applied. Moreover, the amorphous and defective crystal structures of silicon were apparent under the low spark energy condition. The interactions between the wire-EDMing parameters and cut surface characteristics drawn in this study could have significances for the further development of EDM technology towards the fine-scale and damage-free processing of semiconductor materials.

Punturat, Jiraporn; Tangwarodomnukun, Viboon; Dumkum, Chaiya

2014-11-01

345

Quantum dynamics in atomic-fountain experiments for measuring the electric dipole moment of the electron with improved sensitivity  

OpenAIRE

An improved measurement of the electron electric dipole moment (EDM) appears feasible using ground-state alkali atoms in an atomic fountain in which a strong electric field, which couples to a conceivable electron dipole moment (EDM), is applied perpendicular to the fountain axis. In a practical fountain, the ratio of the atomic tensor Stark shift to the Zeeman shift is a facto mu~100. We expand the complete time evolution operator in inverse powers of this ratio; complete r...

Wundt, B. J.; Munger, C. T.; Jentschura, U. D.

2012-01-01

346

Search for an admixture of sterile neutrino in the electron spectrum from tritium $\\beta$-decay  

CERN Document Server

We propose an experiment intended for search for an admixture of sterile neutrino with mass m$_s$ in the range of 1-8 keV that may be detected as specific distortion of the electron energy spectrum during tritium decay. The distortion is spread over large part of the spectrum so to reveal it one can use a detector with relatively poor (near 10-15%) energy resolution. A classic proportional counter is a simple natural choice for a tritium $\\beta$-decay detector. The method we are proposing is original in two respects. First, the counter is produced as a whole from fully-fused quartz tube allowing to measure current pulse directly from anode while providing high stability for a long time. Second, a modern digital acquisition technique can be used in measurements at ultrahigh count rate - up to 10$^6$ Hz. As a result an energy spectrum of tritium electrons containing up to 10$^{12}$ counts may be collected in a month of live time measurements. Due to high statistics an upper limit down to 10$^{-3}$..10$^{-5}$ ca...

Abdurashitov, D; Likhovid, N; Lokhov, A; Tkachev, I; Yants, V

2014-01-01

347

Search for the density effect in inner-shell ionization by ultra relativistic electron impact  

International Nuclear Information System (INIS)

We have extended the measurements of K- and L-shell ionization cross sections by electron impact into the ultra relativistic energy region, 0.9 <= E <= 2.0 GeV, in order to search for a saturation of the cross section. The phenomenon, which is due to the target medium, is called density effect. It is predicted to occur at several hundred MeV impact energy and preferentially for low Z target elements. Theoretical calculations are presented, based on the one-photon exchange approximation. The absolute measurements of the K- and L-shell cross sections for Ni(K), Cu(K), Ag(K,L) and Au(L) performed at the 2.5 GeV electron synchrotron of the University Bonn, however, exhibit that the cross sections show no saturation but are still increasing. Furthermore, from the KX-ray yields, obtained at 0.9 and 2.0 GeV by bombarding the low Z elements S, Ca, Mn, Ni and Ge, we obtain for the corresponding cross section ratio sigmasub(K)(2 GeV)/sigmasub(K)(0.9 GeV) = 1.08 +- 0.012 on the average. (orig./WL)

348

Electron electric dipole moment as a sensitive probe of PeV scale physics  

Science.gov (United States)

We give a quantitative analysis of the electric dipole moments as a probe of high scale physics. We focus on the electric dipole moment of the electron since the limit on it is the most stringent. Further, theoretical computations of it are free of QCD uncertainties. The analysis presented here first explores the probe of high scales via electron electric dipole moment (EDM) within minimal supersymmetric standard model where the contributions to the EDM arise from the chargino and the neutralino exchanges in loops. Here it is shown that the electron EDM can probe mass scales from tens of TeV into the PeV range. The analysis is then extended to include a vectorlike generation which can mix with the three ordinary generations. Here new CP phases arise and it is shown that the electron EDM now has not only a supersymmetric (SUSY) contribution from the exchange of charginos and neutralinos but also a nonsupersymmetric contribution from the exchange of W and Z bosons. It is further shown that the interference of the supersymmetric and the nonsupersymmetric contribution leads to the remarkable phenomenon where the electron EDM as a function of the slepton mass first falls and become vanishingly small and then rises again as the slepton mass increases. This phenomenon arises as a consequence of cancellation between the SUSY and the non-SUSY contribution at low scales while at high scales the SUSY contribution dies out and the EDM is controlled by the non-SUSY contribution alone. The high mass scales that can be probed by the EDM are far in excess of what accelerators will be able to probe. The sensitivity of the EDM to CP phases both in the SUSY and the non-SUSY sectors are also discussed.

Ibrahim, Tarek; Itani, Ahmad; Nath, Pran

2014-09-01

349

Diseño y prueba de un sistema de control de espaciamiento y potencia para Micro-EDM  

Scientific Electronic Library Online (English)

Full Text Available Una vertiente en la evolución de los procesos de manufactura contempla reducir el tamaño de la máquina herramienta de manera proporcional al tamaño de la pieza de trabajo. Las nuevas propuestas para los procesos de micro-manufactura, como micro-EDM (micro-Electrical Discharge Machining), requieren d [...] e parámetros de proceso hasta ahora poco explorados para realizar tareas que demandan alta precisión y productividad. En este trabajo se presenta el desarrollo de un sistema de control de espaciamiento (gap) y de suministro de potencia para realizar procesos de manufactura mediante micro-EDM. Con el objetivo de explorar los valores de los parámetros de manufactura que permitieran mayor remoción de material se utilizó el diseño de experimentos Taguchi. La configuración experimental utiliza un sistema de control acoplado a un circuito RC para controlar el espaciamiento entre el electrodo y la pieza de trabajo, además de un electrodo de cobre de 0.7mm de diámetro. Abstract in english A trend in the evolution of manufacturing processes shows a tendency towards the reduction of the size of the machine tool in a manner proportional to the size of part. Emerging technologies such as micro EDM require process parameters that have been seldom explored in the literature, to perform tas [...] ks that require high precision and productivity. This article presents the development of a circuit for power supply and gap control for micro EDM. To test the circuit, the selection of process parameters that maximize removal rates was explored using a Taguchi experimental design. The experimental confi guration of the micro EDM process used 0.7 mm copper electrodes, controlled by a micro-controller based RC circuit.

Chaides, Oscar; Horacio, Ahuett; Abiud, Flores; Alberto, Caballero; Leopoldo, Ruiz.

2009-03-01

350

Electronic Serials Usage Patterns as Observed at a Medium-Size University: Searches and Full-Text Downloads.  

Directory of Open Access Journals (Sweden)

Full Text Available As the number of electronic serials available to libraries continues to increase while library budgets remain either stagnant or on the decrease, it becomes necessary to evaluate the use of a library’s electronic collection. In 2006, usage statistics were evaluated at Laurentian University, Canada, to provide direction to collection development and identify high-cost low-use electronic serials. Searches and full-text downloads were studied. A sharp increase in use was observed in and around 2004 which can be explained by the introduction, in Ontario, of the ‘double cohort’, by the rapid increase in the number of electronic resources subscribed to at Laurentian, and by the adoption of OpenURL technology. Heavily used electronic serials are identified. Turnaways, connections by IP address and Bradford’s 20:80 rule are also examined. The application of a cost-per-download ratio provided a practical method for identifying underused products.

Alain Raymond Lamothe

2008-06-01

351

Experimental characterization of the inner surface in micro-drilling of spray holes: A comparison between ultrashort pulsed laser and EDM  

Science.gov (United States)

In this research, the inner surface characteristics of micro-drilled holes of fuel injector nozzles were analyzed by Shear Force Microscopy (SHFM). The surface texture was characterized by maximum peak-to-valley distance and periodicity whose dimensions were related to the adopted energy. 180 µm diameter holes were drilled using ultrashort pulsed laser process using pulse energies within the range of 10-50 µJ. Laser ablated surfaces in the tested energy range offer a smooth texture with a peculiar periodic structure with a variation in height between 60 and 90 nm and almost constant periodicity. The Scanning Electron Microscopy (SEM) photograph of the Laser Induced Periodic Surface Structure (LIPSS) showed the co-existence of Low Spatial Frequency LIPSS (LSFL) and High Spatial Frequency LIPSS (HSFL). A comparative analysis was carried out between the highest laser pulse energy in the tested range energy laser drilling which enables the shortest machining time and micro-Electrical Discharge Machining (µ-EDM). On the contrary, results showed that surfaces obtained by electro-erosion are characterized by a random distribution of craters with a total excursion up to 1.5 µm with a periodicity of 10 µm. The mean-squared surface roughness (Rq) derived from the scanned maps ranges between 220 and 560 nm for µ-EDM, and between 50 and 100 nm for fs-pulses laser drilling.

Romoli, L.; Rashed, C. A. A.; Fiaschi, M.

2014-03-01

352

Search for long-lived particles decaying into electron or photon pairs with the D0 detector.  

Science.gov (United States)

In this Letter we report on a search for long-lived particles that decay into final states with two electrons or photons. Such long-lived particles arise in a variety of theoretical models, such as hidden valleys and supersymmetry with gauge-mediated breaking. By precisely reconstructing the direction of the electromagnetic shower we are able to probe much longer lifetimes than previously explored. We see no evidence of the existence of such long-lived particles and interpret this search as a quasi model-independent limit on their production cross section, as well as a limit on a long-lived fourth generation quark. PMID:18851273

Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguilo, E; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Ancu, L S; Andeen, T; Andrieu, B; Anzelc, M S; Aoki, M; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; Asman, B; Assis Jesus, A C S; Atramentov, O; Avila, C; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, P; Banerjee, S; Barberis, E; Barfuss, A-F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benitez, J A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Biscarat, C; Blazey, G; Blekman, F; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Bu, X B; Buchanan, N J; Buchholz, D; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Burnett, T H; Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Carrera, E; Carvalho, W; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Crépé-Renaudin, S; Cuplov, V; Cutts, D; Cwiok, M; da Motta, H; Das, A; Davies, G; De, K; de Jong, S J; De La Cruz-Burelo, E; De Oliveira Martins, C; DeVaughan, K; Degenhardt, J D; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dong, H; Dorland, T; Dubey, A; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Garcia, C; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Geng, W; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Gollub, N; Gómez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jesik, R; Johns, K; Johnson, C; Johnson, M; Johnston, D; Jonckheere, A; Jonsson, P; Juste, A; Kajfasz, E; Kalk, J M; Karmanov, D; Kasper, P A; Katsanos, I; Kau, D; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y M; Khatidze, D; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J-P; Kozelov, A V; Kraus, J; Kuhl, T; Kumar, A; Kupco, A; Kurca, T; Kuzmin, V A; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G; Lebrun, P; Lee, W M; Leflat, A; Lellouch, J; Li, J; Li, L; Li, Q Z; Lietti, S M; Lim, J K; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajicek, M; Love, P; Lubatti, H J; Luna, R; Lyon, A L; Maciel, A K A; Mackin, D; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Maravin, Y; Martin, B; McCarthy, R; Melnitchouk, A; Mendoza, L; Mercadante, P G; Merkin, M; Merritt, K W; Meyer, A; Meyer, J; Mitrevski, J; Mommsen, R K; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nogima, H; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Ochando, C; Onoprienko, D; Oshima, N; Osman, N; Osta, J; Otec, R; Otero Y Garzón, G J; Owen, M; Padley, P; Pangilinan, M; Parashar, N; Park, S-J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Penning, B; Perfilov, M; Peters, K; Peters, Y; Pétroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M-E; Polozov, P; Pope, B G; Popov, A V; Potter, C; Prado da Silva, W L; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Ranjan, K; Ratoff, P N; Renkel, P; Rich, P; Rieger, J; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rodrigues, R F; Rominsky, M; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Sanghi, B; Savage, G; Sawyer, L; Scanlon, T

2008-09-12

353

Search for long-lived particles decaying into electron or photon pairs with the D0 detector  

CERN Document Server

In this Letter we report on a search for long-lived particles that decay into final states with two electrons or photons. Such long-lived particles arise in a variety of theoretical models, like hidden valleys and supersymmetry with gauge-mediated breaking. By precisely reconstructing the direction of the electromagnetic shower we are able to probe much longer lifetimes than previously explored. We see no evidence of the existence of such long-lived particles and interpret this search as a quasi model-independent limit on their production cross section, as well as a limit on a long-lived fourth generation quark.

Abazov, V M; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguiló, E; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Ancu, L S; Andeen, T; Anderson, S; Andrieu, B; Anzelc, M S; Aoki, M; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; sman, B; Assis-Jesus, A C S; Atramentov, O; Avila, C; Badaud, F; Bagby, AL; Baldin, B; Bandurin, D V; Banerjee, P; Banerjee, S; Barberis, E; Barfuss, A F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benítez, J A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Biscarat, C; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Bloom, K; Böhnlein, A; Boline, D; Bolton, T A; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Bu, X B; Buchanan, N J; Buchholz, D; Bühler, M; Büscher, V; Bunichev, V; Burdin, S; Burnett, T H; Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Carvalho, W; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K; Chan, K M; Chandra, A; Charles, F; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M C; Crepe-Renaudin, S; Cuplov, V; Cutts, D; Cwiok, M; Da Motta, H; Das, A; Davies, G; De, K; De Jong, S J; De La Cruz-Burelo, E; De Oliveira Martins, C; Degenhardt, J D; Dliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dong, H; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; García, C; García-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Gel, D; Gerber, C E; Gershtein, Yu; Gillberg, D; Ginther, G; Gollub, N; Gmez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, P; Grivaz, J F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutíerrez, G; Gutíerrez, P; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Harder, K; Harel, A; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jesik, R; Johns, K; Johnson, C; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Kajfasz, E; Kalk, J M; Karmanov, D; Kasper, P A; Katsanos, I; Kau, D; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Yu M; Khatidze, D; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J P; Kozelov, A V; Kraus, J; Kühl, T; Kumar, A; Kupco, A; Kura, T; Kuzmin, V A; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G; Lebrun, P; Lee, W M; Leflat, A; Lellouch, J; Li, J; Li, L; Li, Q Z; Lietti, S M; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajícek, M; Love, P; Lubatti, H J; Luna, R; Lyon, A L; Maciel, A K A; Mackin, D; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martin, B; McCarthy, R; Melnitchouk, A; Mendoza, L; Mercadante, P G; Merkin, M; Merritt, K W; Meyer, A; Meyer, J; Millet, T; Mitrevski, J; Mommsen, R K; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nogima, H; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Ochando, C; Onoprienko, D; Oshima, N; Osman, N; Osta, J; Otec, R; Oteroy-Garzon, G J; Owen, M; Padley, P; Pangilinan, M; Parashar, N; Park, S J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Penning, B; Perfilov, M; Peters, K; Peters, Y; Pétroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M E; Polozov, P; Pope, B G; Popov, A V; Potter, C; Prado da Silva, W L; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Ranjan, K; Ratoff, P N; Renkel, P; Reucroft, S; Rich, P; Rieger, J; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rodrigues, R F; Rominsky, M; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Sanghi, B; Savage, G; Sawyer, L

2008-01-01

354

Slip-rate increase at Parkfield in 1993 detected by high-precision EDM and borehole tensor strainmeters  

Science.gov (United States)

On two of the instrument networks at Parkfield, California, the two-color Electronic Distance Meter (EDM) network and Borehole Tensor Strainmeter (BTSM) network, we have detected a rate change starting in 1993 that has persisted at least 5 years. These and other instruments capable of measuring crustal deformation were installed at Parkfield in anticipation of a moderate, M6, earthquake on the San Andreas fault. Many of these instruments have been in operation since the mid 1980s and have established an excellent baseline to judge changes in rate of deformation and the coherence of such changes between instruments. The onset of the observed rate change corresponds in time to two other changes at Parkfield. From late 1992 through late 1994, the Parkfield region had an increase in number of M4 to M5 earthquakes relative to the preceding 6 years. The deformation-rate change also coincides with the end of a 7-year period of sub-normal rainfall. Both the spatial coherence of the rate change and hydrological modeling suggest a tectonic explanation for the rate change. From these observations, we infer that the rate of slip increased over the period 1993-1998.On two of the instrument networks at Parkfield, California, the two-color Electronic Distance Meter (EDM) network and Borehole Tensor Strainmeter (BTSM) network, we have detected a rate change starting in 1993 that has persisted at least 5 years. These and other instruments capable of measuring crustal deformation were installed at Parkfield in anticipation of a moderate, M6, earthquake on the San Andreas fault. Many of these instruments have been in operation since the mid 1980s and have established an excellent baseline to judge changes in rate of deformation and the coherence of such changes between instruments. The onset of the observed rate change corresponds in time to two other changes at Parkfield. From late 1992 through late 1994, the Parkfield region had an increase in number of M4 to M5 earthquakes relative to the preceding 6 years. The deformation-rate change also coincides with the end of a 7-year period of sub-normal rainfall. Both the spatial coherence of the rate change and hydrological modeling suggest a tectonic explanation for the rate change. From these observations, we infer that the rate of slip increased over the period 1993-1998.

Langbein, J.; Gwyther, R.L.; Hart, R.H.G.; Gladwin, M.T.

1999-01-01

355

The Neutron and the Electron Electric Dipole Moment in N=1 Supergravity Unification  

OpenAIRE

An analysis of the neutron EDM and of the electron EDM in minimal N=1 supergravity unification with two CP violating phases is given. For the neutron the analysis includes the complete one loop gluino, chargino, and neutralino exchange diagrams for the electric dipole and the chromoelectric dipole operators, and also the contribution of the purely gluonic dimension six operator. It is shown that there exist significant regions in the six dimensional parameter space of the mo...

Ibrahim, Tarek; Nath, Pran

1997-01-01

356

Prospects for the measurement of the electron electric dipole moment using YbF  

OpenAIRE

We discuss an experiment underway at Imperial College London to measure the permanent electric dipole moment (EDM) of the electron using a molecular beam of YbF. We describe the measurement method, which uses a combination of laser and radiofrequency resonance techniques to detect the spin precession of the YbF molecule in a strong electric field. We pay particular attention to the analysis scheme and explore some of the possible systematic effects which might mimic the EDM ...

Sauer, B. E.; Hudson, J. J.; Kara, D. M.; Smallman, I. J.; Tarbutt, M. R.; Hinds, E. A.

2011-01-01

357

Spectroscopic Characterization of Thorium Monoxide for use in an Electron Electric Dipole Momement Measurement  

Science.gov (United States)

The ACME Collaboration is searching for the electron electric dipole moment (eEDM) in the metastable H ^3?1 state of thorium monoxide (ThO) using a cryogenic molecular beam.ootnotetextA.C. Vutha et al., Phys. B 43, 074007 (2010) The primary molecular beam source has been fully characterized and optimized.ootnotetextN.R. Hutzler et al., arXiv:1101.4217 (2011) We report on advances in characterizing the spectroscopic properties of the ThO molecule. Transitions necessary for H state preparation and detection have been observed for the the first time, and the saturation parameters for these transitions have been measured. The electric polarizability of the H state and its small g-factor have been measured. The lifetime of a key excited state has been measured. We also report on preliminary results on state preparation and readout of coherent precession phases.

Hess, Paul; Gurevich, Yulia; Hutzler, Nick; Petrik, Elizabeth; Spaun, Benjamin; Doyle, John; Gabrielse, Gerald; Kirilov, Emil; Vutha, Amar; Demille, David

2011-06-01

358

A search for the electric dipole moment of the electron using thorium monoxide  

Science.gov (United States)

This thesis is concerned with the conception, design and construction of an experiment to search for the permanent electric dipole moment of the electron (de) with improved sensitivity. This dipole moment, de, is a hypothesized quantity whose detection, or (in the absence of detection) an improved constraint on its size, would shed some light on the part played by discrete symmetries of space-time in the evolution of our universe. A non-zero d e is evidence of parity and time-reversal violation in fundamental physical processes, and provides an experimental test of many proposed extensions to the Standard Model of particle physics. The experiment takes advantage of the enhanced sensitivity of the H state in the thorium monoxide (ThO) molecule to de. The precession of the spins of the valence electrons in the internal electric field of the molecule is measured using a molecular beam apparatus. This experiment has the potential to improve the experimental limit on de to ˜10-30 e cm, an improvement by a factor of 103 over the current experimental limit. I will describe the analysis that led to the identification of ThO as a favorable system for such an experiment, details of the design and construction of the experimental apparatus, and measurements of various properties of ThO which guide estimates of the statistical sensitivity and the size of potential systematic errors in the experiment. A method of analysis of geometric phase effects in terms of off-resonant energy level shifts, which was developed in order to understand potential systematic errors in this experiment, is also described.

Vutha, Amar Chandra

2011-12-01

359

Search for positron-electron scattering resonances in the MeV range  

International Nuclear Information System (INIS)

This thesis describes experiments for the precise measurement of the energy dependence of the positron-electron scattering cross section and the annihilation in flight of electrons and positrons in the range between 1 and 3 MeV incident energy. The first measurements were dedicated to the elastic e+e--scattering. With the reached precision resonances with lifetimes ?res ? 1.5x10-13 s could be excluded. For the search for resonances with longer lifetimes a completely different measuring method was developed, which suppresses the elastic e+e--scattering by several orders of magnitude. By this the limit in the lifetime could be extended up to ?res ? 3.5x10-12 s. The hitherto given limits for ?res are only valid under the assumption that the resonances decay only again into e+ and e-. Therefore in the third experiment resonances were looked for in the cross section for the two-photon annihilation in flight of e+ and e-. If all the experiments are combined, the strict upper limit is obtained for the internal width of the leptonic decay channel of the hypothetical particle of ? ? 5.7 meV in the whole energy range, whereby the probably essential decay channels are regarded. On the other hand by our measurements resonances cannot be excluded, in which both the e+e- decay and the decay into two ? quanta nd the decay into two ? quanta is possible, and the decay widths of which amount both to some few meV. The latter corresponds again to a lifetime of ?res ? 10-13 s. (orig./HSI)

360

Performance of Silver Coated Copper Tool with Kerosene-servotherm Dielectric in EDM of Monel 400TM  

OpenAIRE

Technologies to improve the material removal rate and reduce the tool removal rate, achieve the good surface finish and dimensional accuracy are very demanding in electrical discharge machining (EDM). The work focused on comparing performance of optimum silver coated copper tool electrode with conventionally used copper tool electrode using optimum proportionate kerosene-servotherm and commercial grade EDM oil in electrical discharge machining of Monel 400TM. The optimum thickness of si...

Joel Daniel; Amirthagadeswaran, K. S.; Jothimurugan, R.

2012-01-01

361

Search for excited electrons and muons in ?s=8 TeV proton–proton collisions with the ATLAS detector  

International Nuclear Information System (INIS)

The ATLAS detector at the Large Hadron Collider is used to search for excited electrons and excited muons in the channel pp ? ??* ? ???, assuming that excited leptons are produced via contact interactions. The analysis is based on 13 fb?1 of pp collisions at a centre-of-mass energy of 8 TeV. No evidence for excited leptons is found, and a limit is set at the 95% credibility level on the cross section times branching ratio as a function of the excited-lepton mass m?*. For m?* ? 0.8 TeV, the respective upper limits on ?B(?* ? ??) are 0.75 and 0.90 fb for the e* and ?* searches. Limits on ?B are converted into lower bounds on the compositeness scale ?. In the special case where ? = m?*, excited-electron and excited-muon masses below 2.2 TeV are excluded. (paper)

362

Searching for Lepton Flavor Violation at a Future High Energy Electron-Positron Collider  

CERN Document Server

We consider theories where lepton flavor is violated, in particular concentrating on the four fermion operator consisting of three electrons and a tau. Strong constraints are available from existing searches for tau -> eee, requiring the scale of the contact interaction to be less than ~(9 TeV)^-2. We reexamine this type of physics, assuming that the particles responsible are heavy (with masses greater than ~TeV) such that a contact interaction description continues to be applicable at the energies for a future e+e- collider. We find that the process e+e- -> e tau can be a very sensitive probe of this kind of physics (even for very conservative assumptions about the detector performance), already improving upon the tau decay bounds to less than ~(11 TeV)^-2 at collider energy sqrt(s) 500 GeV, or reaching beyond ~(35 TeV)^-2 for sqrt(s) = 3 TeV. Even stronger bounds are possible at e-e- colliders in the same energy range.

Murakami, Brandon

2014-01-01

363

Integration of micro milling highspeed spindle on a microEDM-milling machine set-up  

DEFF Research Database (Denmark)

In order to cope with repositioning errors and to combine the fast removal rate of micro milling with the precision and small feature size achievable with micro EDM milling, a hybrid micro-milling and micro-EDM milling centre was built and tested. The aim was to build an affordable set-up, easy to use and adapt to an existing device, not to build a complete new machine. The design requirements will be presented and the set-up described. A geometrical model of the set-up following the small displacement torsor concept is proposed and verified by comparing a simulated and manufactured pocket done by micro milling. Examples of test parts are shown and used as an experimental validation.

De Grave, Arnaud; Hansen, Hans NØrgaard

2009-01-01

364

Post-cast EDM method for reducing the thickness of a turbine nozzle wall  

Science.gov (United States)

A post-cast EDM process is used to remove material from the interior surface of a nozzle vane cavity of a turbine. A thin electrode is passed through the cavity between opposite ends of the nozzle vane and displaced along the interior nozzle wall to remove the material along a predetermined path, thus reducing the thickness of the wall between the cavity and the external surface of the nozzle. In another form, an EDM process employing a profile as an electrode is disposed in the cavity and advanced against the wall to remove material from the wall until the final wall thickness is achieved, with the interior wall surface being complementary to the profile surface.

Jones, Raymond Joseph (Duanesburg, NY); Bojappa, Parvangada Ganapathy (Schenectady, NY); Kirkpatrick, Francis Lawrence (Galway, NY); Schotsch, Margaret Jones (Clifton Park, NY); Rajan, Rajiv (Guilderland, NY); Wei, Bin (Mechanicville, NY)

2002-01-01

365

The Influence of EDM Parameters in Finishing Stage on Surface Quality, MRR and EWR  

Directory of Open Access Journals (Sweden)

Full Text Available The adequate selection of manufacturing conditions is one of the most important aspects to take into consideration in the die-sinking Electrical Discharge Machining (EDM of conductive martial, as these conditions are the ones that are to determine such important characteristics as: surface roughness, Electrode Wear Ratio (EWR and Material Removal Rate(MRR, among others. In this research, the influence of different EDM parameters (current, pulse on-time, pulse off-time, arc voltage on the surface quality ,material removal rate and electrode wear ratio as a result of application copper electrode to cold work steel DIN1.2379 has been investigated. Design of the experiments was chosen full factorial in finishing stage. Finally, the artificial neural network has been employed to predict the surface quality, material removal rate and electrode wear ratio. The experiment results indicated a good performance of proposed method in optimization of such a complex and non-linear problems.

Reza Atefi

2012-05-01

366

Micro-hole machining using micro-EDM combined with electropolishing  

Science.gov (United States)

This paper presents a novel process of using micro-electro-discharge- machining (micro-EDM) combined with electropolishing to improve the surface roughness of micro-holes. During the machining process, a tool is fabricated by wire electro-discharge grinding (WEDG) directly by using micro-EDM for machining the micro-hole and by electropolishing to finish the hole wall. In this work, various micro-holes are machined on the high nickel alloy. By the electropolishing method, high surface quality of the hole wall is obtained by applying a suitable electrolytic voltage and an appropriate concentration of electrolyte in about 5 min of machining time. The taper and burrs of the inlet of holes are reduced, even for difficult- to-machine special-shaped micro-holes. The surface roughness reduced from 2.11 µm Rmax before grinding to 0.69 µm Rmax after electropolishing.

Hung, Jung-Chou; Yan, Biing-Hwa; Liu, Hung-Sung; Chow, Han-Ming

2006-08-01

367

On-line collection and transfer of radioactive noble gas isotopes for radon EDM measurements  

Science.gov (United States)

An apparatus has been developed for on--line collection and transfer to a measurement cell of radon isotopes for optical pumping studies and electric dipole moment (EDM) measurements. Specific isotopes are predicted to have large atomic EDMs due to nuclear octupole deformation or vibration resulting in enhanced sensitivity to CP violation. A low energy isotope separator beam is stopped in a foil. After collection, the foil is heated and the noble gas atoms are cryopumped to a cold finger and then transferred with a buffer gas to a measurement cell. The apparatus has been tested with ^120Xe produced from a ^120Cs beam at the TRIUMF ISAC facility, and greater than 40% efficiency for transfer from the foil to the cell has been demonstrated. The apparatus may also be useful for other measurements with gaseous targets including laser spectroscopy and precision half--life measurements.

Nuss-Warren, Sarah; Tardiff, Eric; Warner, Tim; Ball, Gordon; Behr, John; Chupp, Tim; Coulter, Kevin; Hackman, Greg; Hayden, Michael; Pearson, Matthew; Phillips, Andrew; Smith, Martin; Svensson, Carl

2004-05-01

368

OPTIMIZATION OF OPERATING PARAMETERS FOR EDM PROCESS BASED ON THE TAGUCHI METHOD AND ARTIFICIAL NEURAL NETWORK  

OpenAIRE

In this paper the complexity of electrical discharge machining process which is very difficult to determine optimal cutting parameters for improving cutting performance has been reported. Optimization of operating parameters is an important step in machining, particularly for operating unconventional machiningprocedure like EDM. A suitable selection of machining parameters for the electrical discharge machining process relies heavily on the operators’ technologies and experience because of ...

A.Thillaivanan,; P. Asokan,; K.N.Srinivasan,; Saravanan, R.

2010-01-01

369

Feasibility of wear compensation in micro EDM milling based on discharge counting and discharge population characterization  

DEFF Research Database (Denmark)

This paper investigates the applicability of real time wear compensation in micro EDM milling based on discharge counting and discharge population characterization. Experiments were performed involving discharge counting and tool electrode wear measurement in a wide range of process parameters settings involving different current pulse shapes. A strong correlation is found between average discharge energy of the populations and wear and material removal per discharge. A validation was carried out showing the feasibility of the proposed approach.

Bissacco, Giuliano; Hansen, Hans NØrgaard

2011-01-01

370

Influence of Span 20 Surfactant and Graphite Powder Added in Dielectric Fluid on EDM of Titanium Alloy  

Directory of Open Access Journals (Sweden)

Full Text Available This paper describes an experimental study to evaluate the effect of Span20 surfactant and Graphite powder (additives added to the dielectric fluid on the machining characteristics of the Titanium alloy using Electrical Discharge Machining (EDM. Variation of material removal rate, surface roughness and tool wear rate with respect to the variation in discharge current is evaluated. Comparison is made between the performance characteristics of the Titanium alloy with and without additives added to the dielectric fluid in the machining process. Increase in Material Removal Rate (MRR and decrease in Tool Wear Rate (TWR and Surface Roughness (SR were observed, when the material is machined with additives added in the dielectric fluid compared to the machining of the alloy without additives added in the dielectric fluid. The Scanning Electron Microscope (SEM photograph observed that the recast layer thickness is low and on the machined upper surface less micro cracks and craters are formed. Energy Dispersive Spectroscopy (EDS analysis also indicates that some amounts of material were transferred from electrode to workpiece.

Murahari Kolli

2014-05-01

371

Definitive support by transmission electron microscopy, electron diffraction, and electron density maps for the formation of a BCC lattice from poly[N-[3,4,5-tris(n-dodecan-1-yloxy)benzoyl]ethyleneimine].  

Science.gov (United States)

Transmission electron microscopy (TEM), electron diffraction (ED), and electron density maps (EDM) experiments were carried out on a poly[N-[3,4,5-tris(n-dodecan-1-yloxy)benzoyl]ethyleneimine] [poly[(3,4,5)12G1-Oxz

Duan, H; Hudson, S D; Ungar, G; Holerca, M N; Percec, V

2001-10-01

372

Aspects on the optimization of die-sinking EDM of tungsten carbide-cobalt  

Scientific Electronic Library Online (English)

Full Text Available At present, due to their properties, the tungsten carbide-cobalt (WC-Co) composite materials are in huge demand by industry to manufacture special tools, dies/molds and components under erosion. The powder metallurgy is the usual process applied to obtain WC-Co products, but in some cases this proce [...] ss is unable to produce tools of very complex shapes and highly intricate details. Thus, additional conventional and non-conventional machining processes are required. In this context, the electrical discharge machining (EDM) is an efficient alternative process. However, the EDM parameters have to be properly set for any different tungsten carbide-cobalt composition and electrode material to achieve an appropriate level of machining performance. In this work, a special grade of tungsten carbide-cobalt was used as workpiece and a copper-tungsten alloy as electrode. Experiments on important EDM electrical and non-electrical parameter settings with reference to material removal rate, electrode wear ratio and surface roughness were carried out under typical rough and finish machining. This paper contributes with an attempt to provide insightful guidelines to optimize electrical discharge machining of WC-Co composite materials using CuW alloy electrodes.

Fred Lacerda, Amorim; Walter Lindolfo, Weingaertner; Irionson Antonio, Bassani.

2010-12-01

373

Modeling and optimizing electrodischarge machine process (EDM) with an approach based on genetic algorithm  

Science.gov (United States)

Electro Discharge Machine (EDM) is the commonest untraditional method of production for forming metals and the Non-Oxide ceramics. The increase of smoothness, the increase of the remove of filings, and also the decrease of proportional erosion tool has an important role in this machining. That is directly related to the choosing of input parameters.The complicated and non-linear nature of EDM has made the process impossible with usual and classic method. So far, some methods have been used based on intelligence to optimize this process. At the top of them we can mention artificial neural network that has modelled the process as a black box. The problem of this kind of machining is seen when a workpiece is composited of the collection of carbon-based materials such as silicon carbide. In this article, besides using the new method of mono-pulse technical of EDM, we design a fuzzy neural network and model it. Then the genetic algorithm is used to find the optimal inputs of machine. In our research, workpiece is a Non-Oxide metal called silicon carbide. That makes the control process more difficult. At last, the results are compared with the previous methods.

Zabbah, Iman

2012-01-01

374

Modeling and Analysis of MRR, EWR and Surface Roughness in EDM Milling through Response Surface Methodology  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: Electrical Discharge Machining (EDM has grown over the last few decades from a novelty to a mainstream manufacturing process. Though, EDM process is very demanding but the mechanism of the process is complex and far from completely understood. It is difficult to establish a model that can accurately predict the performance by correlating the process parameters. The optimum processing parameters are essential to increase the production rate and decrease the machining time, since the materials, which are processed by EDM and even the process is very costly. This research establishes empirical relations regarding machining parameters and the responses in analyzing the machinability of the stainless steel. Approach: The machining factors used are voltage, rotational speed of electrode and feed rate over the responses MRR, EWR and Ra. Response surface methodology was used to investigate the relationships and parametric interactions between the three controllable variables on the MRR, EWR and Ra. Central composite experimental design was used to estimate the model coefficients of the three factors. The responses were modeled using a response surface model based on experimental results. The significant coefficients were obtained by performing Analysis Of Variance (ANOVA at 95% level of significance. Results: The variation in percentage errors for developed models was found within 5%. Conclusion: The developed models show that voltage and rotary motion of electrode are the most significant machining parameters influencing MRR, EWR and Ra. These models can be used to get the desired responses within the experimental range.

A. K.M.S. Iqbal

2010-01-01

375

Linear programming analysis of the $R$-parity violation within EDM-constraints  

CERN Document Server

The constraint on the $R$-parity violating supersymmetric interactions is discussed in the light of current experimental data of the electric dipole moment of neutron, $^{129}$Xe , $^{205}$Tl, and $^{199}$Hg atoms, and YbF and ThO molecules. To investigate the constraints without relying upon the assumption of the dominance of a particular combination of couplings over all the rest, an extensive use is made of the linear programming method in the scan of the parameter space. We give maximally possible values for the EDMs of the proton, deuteron, $^3$He nucleus, $^{211}$Rn, $^{225}$Ra, $^{210}$Fr, and the $R$-correlation of the neutron beta decay within the constraints from the current experimental data of the EDMs of neutron, $^{129}$Xe, $^{205}$Tl, and $^{199}$Hg atoms, and YbF and ThO molecules using the linear programming method. It is found that the $R$-correlation of the neutron beta decay and hadronic EDMs are very useful observables to constrain definite regions of the parameter space of the $R$-parity...

Yamanaka, Nodoka; Kubota, Takahiro

2014-01-01

376

Linear programming analysis of the R-parity violation within EDM-constraints  

Science.gov (United States)

The constraint on the R-parity violating supersymmetric interactions is discussed in the light of current experimental data of the electric dipole moment of neutron, 129Xe , 205Tl, and 199Hg atoms, and YbF and ThO molecules. To investigate the constraints without relying upon the assumption of the dominance of a particular combination of couplings over all the rest, an extensive use is made of the linear programming method in the scan of the parameter space. We give maximally possible values for the EDMs of the proton, deuteron, 3He nucleus, 211Rn, 225Ra, 210Fr, and the R-correlation of the neutron beta decay within the constraints from the current experimental data of the EDMs of neutron, 129Xe, 205Tl, and 199Hg atoms, and YbF and ThO molecules using the linear programming method. It is found that the R-correlation of the neutron beta decay and hadronic EDMs are very useful observables to constrain definite regions of the parameter space of the R-parity violating supersymmetry.

Yamanaka, Nodoka; Sato, Toru; Kubota, Takahiro

2014-12-01

377

Development of a high precision tabletop versatile CNC wire-EDM for making intricate micro parts  

Science.gov (United States)

The micro-electrical discharge machining (micro-EDM) process has been proved to be appropriate for making 3D micro parts that are difficult and even impossible to manufacture by other processes. In this paper a high precision tabletop CNC wire electrical discharge machine (wire EDM) designed specifically for machining complex shape micro parts or structures is developed. In the machine developed, a novel micro-wire-cutting mechanism is designed, an approach to control wire tension by magnetic force is proposed and a servo feed control strategy, in accordance with the measured gap voltage, is designed and implemented. To verify the functions and capabilities of the machine developed, several thick micro outer and internal spur gears and rack are machined. It shows that the taper angle along the wall or cavity of a part that appears when other micro-EDM processes are applied can be avoided. A very good dimensional accuracy of 1 µm and a surface finish of Rmax equal to 0.64 µm are achieved. The satisfactory cutting of a miniature 3D pagoda with a micro-hooked structure also reveals that the machine developed is versatile, and can be used as a new tool for making intricate micro parts.

Liao, Yunn-Shiuan; Chen, Shun-Tong; Lin, Chang-Sheng

2005-02-01

378

Investigation of EDM characteristics of Nickel-based heat resistant alloy  

Energy Technology Data Exchange (ETDEWEB)

The EDM processing characteristics of one of the nickel-based heat resistant alloys, Hastelloy-X, were investigated under the various EDM conditions and analyzed in terms of surface integrity. This alloy is commonly used as a material for the hot gas path component of gas turbines and it is difficult to machine by conventional machining methods. The primary EDM parameter which was varied in this study were the pulse-on time. Since the pulse-on time is one of the main factors that determines the intensity of the electrical discharge energy, it was expected that the machining ratio and the surface integrity of the specimens would be proportionally dependent on the pulse-on duration. However, experimental results showed that MRR (Material Removal Rate) and EWR (Electrode Wear Rate) behaved nonlinearly with respect to the pulse duration, whereas the morphological and metallurgical features showed rather a constant trend of change by the pulse duration. In addition the heat treating process affected the recast layer and HAZ to be recrystallized but softening occurred in recast layer only. A metallurgical evaluation of the microstructure for the altered material zone was also conducted.

Kang, Sin Ho; Kim, Dae Eun [Yonsei Univ., Seoul (Korea, Republic of)

2003-10-01

379

Investigation of EDM characteristics of Nickel-based heat resistant alloy  

International Nuclear Information System (INIS)

The EDM processing characteristics of one of the nickel-based heat resistant alloys, Hastelloy-X, were investigated under the various EDM conditions and analyzed in terms of surface integrity. This alloy is commonly used as a material for the hot gas path component of gas turbines and it is difficult to machine by conventional machining methods. The primary EDM parameter which was varied in this study were the pulse-on time. Since the pulse-on time is one of the main factors that determines the intensity of the electrical discharge energy, it was expected that the machining ratio and the surface integrity of the specimens would be proportionally dependent on the pulse-on duration. However, experimental results showed that MRR (Material Removal Rate) and EWR (Electrode Wear Rate) behaved nonlinearly with respect to the pulse duration, whereas the morphological and metallurgical features showed rather a constant trend of change by the pulse duration. In addition the heat treating process affected the recast layer and HAZ to be recrystallized but softening occurred in recast layer only. A metallurgical evaluation of the microstructure for the altered material zone was also conducted

380

Search for excited electrons in ppbar collisions at $\\sqrt{s}$ = 1.96 TeV  

CERN Document Server

We present the results of a search for the production of an excited state of the electron, e*, in proton-antiproton collisions at $\\sqrt{s}$ = 1.96 TeV. The data were collected with the D0 experiment at the Fermilab Tevatron Collider and correspond to an integrated luminosity of approximately 1 fb^-1. We search for e* in the process ppbar -> e* e, with the e* subsequently decaying to an electron plus photon. No excess above the standard model background is observed. Interpreting our data in the context of a model that describes e* production by four-fermion contact interactions and e* decay via electroweak processes, we set 95% C.L. upper limits on the production cross section ranging from 8.9 fb to 27 fb, depending on the mass of the excited electron. Choosing the scale for contact interactions to be Lambda = 1 TeV, excited electron masses below 756 GeV are excluded at the 95% C.L.

Abazov, V; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguiló, E; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Ancu, L S; Andeen, T; Anderson, S; Andrieu, B; Anzelc, M S; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; sman, B; Assis-Jesus, A C S; Atramentov, O; Autermann, C; Avila, C; Ay, C; Badaud, F; Baden, A A; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Banerjee, P; Barberis, E; Barfuss, A F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benítez, J A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Biscarat, C; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Bloom, K; Böhnlein, A; Boline, D; Bolton, T A; Borissov, G; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Buchanan, N J; Buchholz, D; Bühler, M; Büscher, V; Bunichev, V; Burdin, S; Burke, S; Burnett, T H; Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Carvalho, W; Casey, B C K; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chan, K; Chandra, A; Charles, F; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Cihangir, S; Claes, D; Coadou, Y; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M C; Crepe-Renaudin, S; Cutts, D; Cwiok, M; Da Motta, H; Das, A; Davies, eeG; De, K; De Jong, S J; De La Cruz-Burelo, E; De Oliveira Martins, C; Degenhardt, J D; Dliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, e A; Dong, H; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Ford, M; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; García, C; García-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Gel, D; Gerber, eC E; Gershtein, Yu; Gillberg, D; Ginther, G; Gollub, N; Gmez, B; Goussiou, A; Grannis, P D; Greenlee, o H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, P; Grivaz, J F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, J; Guo, F; Gutíerrez, P; Gutíerrez, G; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Hansson, P; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hong, S J; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, e K; Jarvis, C; Jesik, R; Johns, K; Johnson, C; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Kajfasz, E; Kalinin, A M; Kalk, J R; Kalk, J M; Kappler, S; Karmanov, D; Kasper, P A; Katsanos, I; Kau, D; Kaur, R; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Yu M; Khatidze, D; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J P; Korablev, V M; Kozelov, A V; Krop, D; Kühl, T; Kumar, A; Kunori, S; Kupco, A; Kura, T; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G; Lebrun, P; Lee, cW M; Leflat, A; Lehner, F; Lellouch, J; Lévêque, J; Li, J; Li, Q Z; Li, L; Lietti, S M; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajícek, M; Love, P; Lubatti, H J; Luna, R; Lyon, A L; Maciel, A K A; Mackin, D; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martin, B; McCarthy, R; Melnitchouk, A; Mendoza, L; Mercadante, P G; Merkin, M; Merritt, K W; Meyer, J; Meyer, A; Millet, T; Mitrevski, J; Molina, J; Mommsen, R K; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulders, M; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nogima, H; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Ochando, C; Onoprienko, D; Oshima, N; Osta, J; Otec, R; Oteroy-Garzon, G J; Owen, M; Padley, P; Pangilinan, M; Parashar, N; Park, S J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Penning, B; Perfilov, M; Peters, K; Peters, Y; Ptroff, P; Petteni, M; Piegaia, cR; Piper, J; Pleier, M A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M E; Polozov, P; Pope, B G; Popov, A V; Potter, C; Prado da Silva, W L; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Ranjan, K; Ratoff, P N; Renkel, P; Reucroft, S; Rich, P; Rieger, J; Rijssenbeek, M

2008-01-01

381

Electronic Serials Usage Patterns as Observed at a Medium-Size University: Searches and Full-Text Downloads  

Directory of Open Access Journals (Sweden)

Full Text Available while library budgets remain either stagnant or on the decrease, it becomesnecessary to evaluate the use of a library's electronic collection. In 2006, usagestatistics were evaluated at Laurentian University, Canada, to provide direction tocollection development and identify high-cost low-use electronic serials.Searches and full-text downloads were studied. A sharp increase in use wasobserved in and around 2004 which can be explained by the introduction, inOntario, of the 'double cohort', by the rapid increase in the number of electronicresources subscribed to at Laurentian, and by the adoption of OpenURLtechnology. Heavily used electronic serials are identified. Turnaways,connections by IP address and Bradford's 20:80 rule are also examined. Theapplication of a cost-per-download ratio provided a practical method foridentifying underused products.

Alain Lamothe

2008-06-01

382

Avaliação da Geração de Microtrincas do Aço Rápido ABNT M2 no Processo EDM com Adição de SiC - DOI: 10.4025/actascitechnol.v30i2.543 Evaluation of the Microcrack Generation of ABNT M2 High Speed Steel in EDM Process With Addition of Silicon Carbide Powder - DOI: 10.4025/actascitechnol.v30i2.543  

Directory of Open Access Journals (Sweden)

Full Text Available É sabido que a Usinagem por Descargas Elétricas (EDM, é um processo térmico onde pode-se ter temperaturas muito elevadas (superiores a 1200 °C na região de usinagem. Conseqüentemente é fácil de entender o fato das peças usinadas por EDM, apresentarem camadas superficiais endurecidas, refundidas e com elevado números de microtrincas superfíciais. A formação de microtrincas está associada com o desenvolvimento de altas tensões térmicas que excedem a tensão máxima de resistência do material. Além disso as microtrincas superficiais penetram em profundidade com extensões que dependem da energia de descarga. O trabalho proposto, tem por objetivo estudar o efeito da adição de pó de SiC em vários fluidos dielétricos, sobre a geração de microtrincas superficiais, no aço rápido ABNT M2, durante a usinagem por descargas elétricas. Os resultados apresentados mostram uma redução da quantidade de microtrincas nas superfícies usinadas, quando se adiciona pó de SiC ao dielétrico, quando comparadas com as usinadas com EDM convencional.It is known that Electrical Discharge Machining (EDM, it is a thermal process where it can be had very high temperatures (higter than 1200° C in the region of machining consequently is easy to understand that during each electric discharge, hight temperatures are generated, causing local fusion or even evaporation of the material machined. In each discharge, a crater is formed in the material and a small crater is formed in the electrode. Of every melted material produced in each discharge, only 15%, or minus, it is removed through the dielectric liquid. The remaining of the melted material solidifies forming a wrinkled surface. The characteristics of the surface obtained, overlap of craters, globules of sullage, “chimneys ", bubbles (formed when the gases arrested are liberated through the material resolidificado, they are revealed through an analysis by scanning electron microscope. O proposed work, has for objective to study the effect of the addition of powder of SiC in several dielectric fluids, on microcrack generation, in workpiece of the high speed steel (ABNT M2, during the electrical discharge machining. The presented results show that the samples machined with the addition of powders of SiC presented significant reduction of the number of microcrack in the surface machined, when compared with the machined with conventional EDM.

José Roberto Pereira Rodrigues

2008-10-01

383

Measurement cell development for the neutron EDM experiment  

Science.gov (United States)

An experimental search for the neutron electric dipole moment is under development for installation at the Oak Ridge Spallation Neutron Source. The experiment will use ultracold neutrons (UCN) produced in superfluid helium, along with ^3He that will act as a neutron spin analyzer and comagnetometer. The measurement will take place in two 3-liter rectangular acrylic cells coated with deuterated tetraphenyl butadiene (dTPB) in a deuterated polystyrene (dPS) matrix. It is crucial for the ultimate sensitivity of the experiment that UCN survive many (˜10^5) wall collisions without being lost. We are currently testing the UCN storage properties of dPS+dTPB coated acrylic cells at the LANSCE solid deuterium UCN source. The test cell is filled with UCN through a 1 cm diameter opening, sealed with a valve carefully designed to have very low UCN losses, and then after waiting for between 20-1000 seconds the valve is opened and the remaining UCN are counted. Measurements are carried out from room temperature to below 20 K to determine the temperature dependence of the UCN wall losses. We will discuss cell construction techniques and present recent UCN storage measurements. This work is supported by the U. S. Department of Energy.

Griffith, W. C.; Clayton, S. M.; Cooper, M. D.; Currie, S. A.; Ito, T. M.; Makela, M. F.; Ramsey, J. C.; Saunders, A.

2012-10-01

384

Searching for physics beyond the Standard Model through the dipole interaction  

Science.gov (United States)

The magnetic dipole interaction played a central role in the development of QED, and continued in that role for the Standard Model. The muon anomalous magnetic moment has served as a benchmark for models of new physics, and the present experimental value is larger than the standard-model value by more than three standard deviations. The electric dipole moment (EDM) violates parity (P) and time-reversal (T) symmetries, and in the context of the CPT theorem, the combination of charge conjugation and parity (CP). Since a new source of CP violation outside of that observed in the K and B meson systems is needed to help explain the baryon asymmetry of the universe, searches for EDMs are being carried out worldwide on a number of systems. The standard-model value of the EDM is immeasurably small, so any evidence for an EDM would signify the observation of new physics. Unique opportunities exist for EDM searches using polarized proton, deuteron or muon beams in storage rings. This talk will provide an overview of the theory of dipole moments, and the relevant experiments. The connection to the transition dipole moment that could produce lepton flavor violating interactions such as ?+ ? e+? is also mentioned.

Roberts, B. Lee

2011-05-01

385

Searching for physics beyond the Standard Model through the dipole interaction  

CERN Document Server

The magnetic dipole interaction played a central role in the development of QED, and continued in that role for the Standard Model. The muon anomalous magnetic moment has served as a benchmark for models of new physics, and the present experimental value is larger than the standard-model value by more than three standard deviations. The electric dipole moment (EDM) violates parity ({$P$}) and time-reversal ({$T$}) symmetries, and in the context of the $CPT$ theorem, the combination of charge conjugation and parity ($CP$). Since a new source of {$ CP$} violation outside of that observed in the $K$ and $B$ meson systems is needed to help explain the baryon asymmetry of the universe, searches for EDMs are being carried out worldwide on a number of systems. The standard-model value of the EDM is immeasurably small, so any evidence for an EDM would signify the observation of new physics. Unique opportunities exist for EDM searches using polarized proton, deuteron or muon beams in storage rings. This talk will prov...

Roberts, B Lee

2011-01-01

386

Search for Fermi shuttle mechanisms in electron emission from atomic collision sequences  

International Nuclear Information System (INIS)

In electron spectra induced by slow heavy ion bombardment of solids a high energy tail can be observed, which is suggested to be explained by multiple collision sequences. In order to find those multiple collision effects like the ''Fermi shuttle'' acceleration mechanism we measured doubly differential electron emission cross sections for H+ (33.5-700 keV) impact on different targets (He, Ne, C and Au) as a function of projectile energy and electron emission angle. We observed a surprising target dependence of the electron emission within the range of electron energies close to that of the binary encounter electrons for all observed angles of emission. (orig.)

387

A first search of excited states double beta and double electron capture decays of Pd110 and Pd102  

CERN Document Server

A search for double beta decays of the palladium isotopes Pd110 and Pd102 into excited states of their daughters was performed. New half-life limits for the 2nubb and 0nubb decays into first excited 0+ and 2+ states of 2.54e19 yr and 2.14e19 yr (95% CL) for the Pd110 decay were obtained improving limits by two orders of magnitude. The corresponding half-lives for double electron capture transition of Pd102 are 1.73e18 yr and 2.54e18 yr (95% CL) respectively. These are the first measurements for Pd102.

Lehnert, Bjoern

2011-01-01

388

Integrated Management Systems and Workflow-Based Electronic Document Management: An Empirical Study  

DEFF Research Database (Denmark)

Purpose: Many global organizations have aligned their strategy and operation via the ISO-based framework of integrated management system (IMS) that allows them to merge quality, environment, health and safety management systems. In such context, having a robust electronic document management system (EDMS) is essential, especially at global enterprises where a large amount of documents generated by processes flows through different work cultures. However, there is no "one-size-fits-all" design for EDMS because it depends on organizations' needs, size and resource allocation. This article discusses the interrelation between EDMS and IMS in order to suggest a best practice. Design/methodology/approach: This article methodologically based upon a qualitative, interpretivistic, longitudinal empirical study in a wind turbine factory. Findings and Originality/value: IMS improvement and effectiveness has been overlooking EDMS as a key factor in establishing appropriate technological support of the IMS processes. Rightful application of EDMS can further contribute to organizational learning, precision of documentation and cross-organisational collaboration. Research limitations/implications: Theorising on IMS needs a stronger perspective of the technological limitations and potentials of basing IMS on EDMS. Practical implications: IMS are complex systems involving a large number of administrative functions. EDMS provides a formal representation with automation potentials both heightening and securing document trustworthiness. Social implications: IMS has a tendency to stay with professionals, e.g. line managers and QA/QC/QMS professionals. The EDMS line of discussion suggests a broader inclusion. Originality/value: Researching IMS as a technological implementation is giving a better platform of aligning the IMS with other business processes and is bringing IMS closer to the operational activities within the enterprise.

Pho, Hang Thu; Tambo, Torben

2014-01-01

389

Integrated management systems and workflow-based electronic document management: An empirical study  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: Many global organizations have aligned their strategy and operation via the ISO-based framework of integrated management system (IMS that allows them to merge quality, environment, health and safety management systems. In such context, having a robust electronic document management system (EDMS is essential, especially at global enterprises where a large amount of documents generated by processes flows through different work cultures. However, there is no "one-size-fits-all" design for EDMS because it depends on organizations' needs, size and resource allocation. This article discusses the interrelation between EDMS and IMS in order to suggest a best practice. Design/methodology/approach: This article methodologically based upon a qualitative, interpretivistic, longitudinal empirical study in a wind turbine factory. Findings and Originality/value: IMS improvement and effectiveness has been overlooking EDMS as a key factor in establishing appropriate technological support of the IMS processes. Rightful application of EDMS can further contribute to organizational learning, precision of documentation and cross-organisational collaboration. Research limitations/implications: Theorising on IMS needs a stronger perspective of the technological limitations and potentials of basing IMS on EDMS. Practical implications: IMS are complex systems involving a large number of administrative functions. EDMS provides a formal representation with automation potentials both heightening and securing document trustworthiness. Social implications: IMS has a tendency to stay with professionals, e.g. line managers and QA/QC/QMS professionals. The EDMS line of discussion suggests a broader inclusion. Originality/value: Researching IMS as a technological implementation is giving a better platform of aligning the IMS with other business processes and is bringing IMS closer to the operational activities within the enterprise.

Hang Thu Pho

2014-01-01

390

Local spin torque induced by electron electric dipole moment in the Ybf molecule  

Science.gov (United States)

In this study, we show the modification of the equation of motion of the electronic spin, which is derived by the quantum electron spin vorticity principle, by the effect of the electron electric dipole moment (EDM). To investigate the new contribution to spin torque by EDM, using first principle calculations, we visualize distributions of the local spin angular momentum density and local spin torque density of the YbF molecule on which the static electric field and magnetic field are applied at t = 0.

Fukuda, Masahiro; Senami, Masato; Ogiso, Yoji; Tachibana, Akitomo

2014-10-01

391

Local spin torque induced by electron electric dipole moment in the YbF molecule  

International Nuclear Information System (INIS)

In this study, we show the modification of the equation of motion of the electronic spin, which is derived by the quantum electron spin vorticity principle, by the effect of the electron electric dipole moment (EDM). To investigate the new contribution to spin torque by EDM, using first principle calculations, we visualize distributions of the local spin angular momentum density and local spin torque density of the YbF molecule on which the static electric field and magnetic field are applied at t = 0

392

Local spin torque induced by electron electric dipole moment in the YbF molecule  

Energy Technology Data Exchange (ETDEWEB)

In this study, we show the modification of the equation of motion of the electronic spin, which is derived by the quantum electron spin vorticity principle, by the effect of the electron electric dipole moment (EDM). To investigate the new contribution to spin torque by EDM, using first principle calculations, we visualize distributions of the local spin angular momentum density and local spin torque density of the YbF molecule on which the static electric field and magnetic field are applied at t = 0.

Fukuda, Masahiro; Senami, Masato; Ogiso, Yoji; Tachibana, Akitomo [Department of Micro Engineering, Kyoto University, Kyoto 615-8540 (Japan)

2014-10-06

393

Combined GPS, EDM and triangulation surveys of the rapid down-slope motion of the western flank of Arenal Volcano, Costa Rica  

Science.gov (United States)

Here we present initial conclusion of a one year-long combined geodesy campaign on Arenal Volcano, in Costa Rica (2008-2009). Our data shows evidence for an active local tectonic surrounding and a 7cm/yr displacement field on the western flank of the volcano edifice that is in general agreement with recent INSAR studies. Moreover, the rigorous combination of simultaneous GPS, EDM and triangulation measurements provide a time-cost effective approach to volcanic monitoring. Arenal volcano, in Costa Rica, is an active basaltic andesite stratovolcano located at the southern end of the Guanacaste volcanic range. Arenal's current long-lived magmatic activity may be coming to an end but downslope motion of the western flank suggests a risk of sector collapse. In order to study this, during 2008 and 2009 we deployed a joint geodetic network, comprising GPS, EDM (Electronic Distance Measurements) and triangulation measurements on a total of 12 benchmarks. Nine benchmarks monitor movements of the western flank of Arenal while three external benchmarks, located away from the volcanic system, monitor local tectonic movements. A joint adjustment of the combined network using the software suite GAMIT, FONDA and GLOBK allowed us to maintain a high repeatability along the time despite short field campaigns. In agreement with a quantitative comparison with existing INSAR, our results show a downward displacement on the western flank. However, in our full 3D survey, we observe that these displacements shift to a northern and even northeastern direction at the foot of the volcano. This suggests that if a sector collapse is underway it must have a northwestern direction. Our favoured preliminary explanation is, in agreement with local workers, that the deformation is caused by the weight of the recent lava field. The differential displacements between the three external points agree with neotectonic studies of the presence of active faults in the north of the Arenal graben.

Muller, C.; del Potro, R.; Gottsmann, J.; Biggs, J.; Van der Laat, R.

2011-12-01

394

Relationship of Surface Roughness with Current and Voltage During Wire EDM  

OpenAIRE

Wire EDM is in use for a long time for cutting punches and dies, shaped pockets and other machine parts. Surface finish of the machined surface mainly depends on current and voltage used during machining. In the present research experimental investigations have been conducted to establish relationships of job surface finish with current and voltage. Brass wires of diameters 0.3, 0.25, 0.20 and 0.15 mm were used. Work materials tested were mild steel, aluminum, cemented carbide, copper and sta...

Ahsan Ali Khan; Munira Bt. Mohd Ali; Norhashimah Bt. Mohd Shaffiar

2006-01-01

395

Mixing of the CP Even and the CP Odd Higgs Bosons and the EDM Constraints  

OpenAIRE

The mixing among the CP even and the CP odd neutral Higgs bosons of MSSM by one loop induced effects in the presence of CP phases is investigated using three different mechanisms to satisfy the EDM constraints, i.e., a fine tuning of phases, a heavy sparticle spectrum, and the cancellation mechanism. It is shown that if a mixing effect among the CP even and the CP odd Higgs bosons is observed experimentally, then it is only the cancellation mechanism that can survive under t...

Ibrahim, Tarek

2001-01-01

396

High-speed micro electrode tool fabrication by a twin-wire EDM system  

Science.gov (United States)

This paper describes a new machining process which combines twin-electro-wire together with two electro discharge circuits to rapidly fabricate micro electrode tools. The results show that transistor electro discharge and RC electro discharge circuits coexist to fabricate micro tools with rough and finish machining both on the same machine. Compared to conventional wire electro discharge grinding (WEDG) technology, a twin-wire EDM system that combines rough and finish machining into one process allows the efficient fabrication of micro tools. This high-speed micro tool fabrication process can be applied not only to micro electrode machining but also to micro punching tool and micro probing tips machining.

Sheu, Dong-Yea

2008-10-01

397

High-speed micro electrode tool fabrication by a twin-wire EDM system  

International Nuclear Information System (INIS)

This paper describes a new machining process which combines twin-electro-wire together with two electro discharge circuits to rapidly fabricate micro electrode tools. The results show that transistor electro discharge and RC electro discharge circuits coexist to fabricate micro tools with rough and finish machining both on the same machine. Compared to conventional wire electro discharge grinding (WEDG) technology, a twin-wire EDM system that combines rough and finish machining into one process allows the efficient fabrication of micro tools. This high-speed micro tool fabrication process can be applied not only to micro electrode machining but also to micro punching tool and micro probing tips machining

398

A framework to analyze searches for gauge bosons of the hidden light sector in electron scattering fixed target experiments  

International Nuclear Information System (INIS)

Electron scattering fixed target experiments are a versatile tool to probe various kinds of physics phenomena. Recently fixed target experiments in which an electron beam is scattered off a heavy nucleus and a lepton-antilepton pair is created, i.e. e(A,Z) ?e(A,Z)l+l?, were utilized to search for physics beyond the standard model at modest energies. In these experiments one searches for a small, narrow resonance in the invariant mass spectrum of the lepton-antilepton pair, arising from the exchange of a new light gauge boson ?? coupling to the dark sector as well as very weakly to standard model particles. Such a signal would appear as an enhancement over a smooth QED background. Hence a precise understanding of the background is crucial. We present a theoretical analysis of the process e(A,Z) ?e(A,Z)l+l?. Therefore we have performed an analysis of the cross section, which is then used to extract exclusion limits on the parameter space of the ??, describing the existing experimental data taken at MAMI

399

APEX: An electron fixed-target experiment to search for a new vector boson A? Decaying to e+e?  

International Nuclear Information System (INIS)

The A' EXperiment (APEX) is designed to search for new vector bosons that have small couplings to charged particles. Such vectors can arise naturally from a small kinetic mixing of a new 'dark photon' (A') with the photon - one of the very few ways in which new forces can couple to the Standard Model - and have received considerable attention as an explanation of various dark matter related anomalies. A' bosons are produced by radiation off an electron beam, and could appear as narrow resonances with small production cross-section in the QED e+e? spectrum. We plan to search for an A' using the CEBAF electron beam at energies of 1-4 GeV incident on 0.5-10% radiation length multi-foil tungsten targets, and measure the resulting e+e? pairs using the High Resolution Spectrometers and a septum magnet in Hall A at Jefferson Lab. With a 33-day run, APEX will explore the region 50 MeV A? ?7. This proceeding summarizes the experiment, test run results, and comments on future plans

400

The generalized simulated annealing algorithm in the low energy electron diffraction search problem  

International Nuclear Information System (INIS)

We present in this work results concerning the application of the generalized simulated annealing (GSA) algorithm to the LEED search problem. The influence of the visiting distribution function (defined by the so-called qV parameter) in the effectiveness of the method was investigated by the application of the algorithm to structural searches for optimization of two to ten parameters in a theory-theory comparison for the CdTe(110) system. Results, obtained with the scaling relation and probability of convergence as a function of the number of parameters to be varied, indicate the fast simulated annealing (FSA) (qV = 2.0) approach as the best search machine

401

Electron and Neutron Electric Dipole Moments in the Constrained MSSM  

OpenAIRE

We analyze the effects of CP-violating phases on the electric dipole moment (EDM) of electron and neutron in the constrained minimal supersymmetric model. We find that the phases phi_{\\mu} and phi_{A_0} have to be strongly correlated, in particular for small values of the SUSY mass parameters. We calculate the neutron EDM in two different models, the Quark-Parton Model and the Chiral Quark Model. It turns out that the predictions are quite sensitive to the model used. We sho...

Bartl, A.; Gajdosik, T.; Porod, W.; Stockinger, P.; Stremnitzer, H.

1999-01-01

402

Search for Excited or Exotic Electron Production Using the Dielectron + Photon Signature at CDF in Run II  

Energy Technology Data Exchange (ETDEWEB)

The author presents a search for excited or exotic electrons decaying to an electron and a photon with high transverse momentum. An oppositely charged electron is produced in association with the excited electron, yielding a final state dielectron + photon signature. The discovery of excited electrons would be a first indication of lepton compositeness. They use {approx} 202 pb{sup -1} of data collected in p{bar p} collisions at {radical}s = 1.96 TeV with the Collider Detector at Fermilab during March 2001 through September 2003. The data are consistent with standard model expectations. Upper limits are set on the experimental cross-section {sigma}({bar p}p {yields} ee* {yields} ee{gamma}) at the 95% confidence level in a contact-interaction model and a gauge-mediated interaction model. Limits are also presented as exclusion regions in the parameter space of the excited electron mass (M{sub e*}) and the compositeness energy scale ({Lambda}). In the contact-interaction model, for which there are no previously published limits, they find M{sub e*} < 906 GeV is excluded for M{sub e*} = {Lambda}. In the gauge-mediated model, the exclusion region in the M{sub e*} versus the phenomenological coupling f/{Lambda} parameter space is extended to M{sub e*} < 430 GeV for f/{Lambda} {approx} 10{sup -2} GeV{sup -1}. In comparison, other experiments have excluded M{sub e*} < 280 GeV for f/{Lambda} {approx} 10{sup -2} GeV{sup -1}.

Gerberich, Heather Kay; /Duke U.

2004-07-01

403

Search for resonant electron transfer and double excitation in Kr34+ + H2 collisions  

International Nuclear Information System (INIS)

Resonant electron transfer and double excitation (RME) is a correlated electron process which is expected to occur in an ion-atom collision when electron capture is accompanied by the simultaneous excitation of two inner-shell electrons. RT2 is similar to resonant transfer excitation (RTE) in which only a single electron is excited. RT2E was investigated experimentally for 38--42 MeV/u Kr34 + H2 collisions by observing x-ray emission associated with single-electron capture. No events associated with Kr K x rays (near 13 keV were observed; however, events do occur at about twice (> 22 keV) the Kr K x-ray energy. Several possible sources of these latter x rays have been considered

404

Microgravity Electron Electric Dipole Moment Experiment with a Cold Atom Beam  

Science.gov (United States)

New physics beyond the Standard Model: The small CP violation contained in the Standard Model is insufficient to account for the baryon/antibaryon asymmetry in the universe. New sources of CP violation are provided by extensions to the Standard Model. They contain CP-violating phases that couple directly to leptons and from which a large electron electric dipole moment (EDM) may be generated. Observation of an electron EDM would be proof of a Standard Model extension because the Standard Model only allows an electron EDM of less than 10(exppp -57) C-m (S.I. units; 1 C-m = 1.6 x 10(exp -21) e-cm). A null result, however, constrains models and improving the limit tightens constraints, further restricting the models.

Gould, Harvey

2003-01-01

405

An Electron Fixed Target Experiment to Search for a New Vector Boson A' Decaying to e+e-  

Energy Technology Data Exchange (ETDEWEB)

We describe an experiment to search for a new vector boson A' with weak coupling {alpha}' {approx}> 6 x 10{sup -8} {alpha} to electrons ({alpha} = e{sup 2}/4{pi}) in the mass range 65 MeV < m{sub A'} < 550 MeV. New vector bosons with such small couplings arise naturally from a small kinetic mixing of the 'dark photon' A' with the photon - one of the very few ways in which new forces can couple to the Standard Model - and have received considerable attention as an explanation of various dark matter related anomalies. A' bosons are produced by radiation off an electron beam, and could appear as narrow resonances with small production cross-section in the trident e{sup +}e{sup -} spectrum. We summarize the experimental approach described in a proposal submitted to Jefferson Laboratory's PAC35, PR-10-009. This experiment, the A' Experiment (APEX), uses the electron beam of the Continuous Electron Beam Accelerator Facility at Jefferson Laboratory (CEBAF) at energies of {approx} 1-4 GeV incident on 0.5-10% radiation length Tungsten wire mesh targets, and measures the resulting e{sup +}e{sup -} pairs to search for the A' using the High Resolution Spectrometer and the septum magnet in Hall A. With a {approx} 1 month run, APEX will achieve very good sensitivity because the statistics of e{sup +}e{sup -} pairs will be {approx} 10,000 times larger in the explored mass range than any previous search for the A' boson. These statistics and the excellent mass resolution of the spectrometers allow sensitivity to {alpha}'/{alpha} one to three orders of magnitude below current limits, in a region of parameter space of great theoretical and phenomenological interest. Similar experiments could also be performed at other facilities, such as the Mainz Microtron.

Essig, Rouven; Schuster, Philip; /SLAC; Toro, Natalia; /Stanford U., Phys. Dept.; Wojtsekhowski, Bogdan; /Jefferson Lab

2010-06-11

406

Electro-thermal modelling of anode and cathode in micro-EDM  

International Nuclear Information System (INIS)

Micro-electrical discharge machining is an evolution of conventional EDM used for fabricating three-dimensional complex micro-components and microstructure with high precision capabilities. However, due to the stochastic nature of the process, it has not been fully understood. This paper proposes an analytical model based on electro-thermal theory to estimate the geometrical dimensions of micro-crater. The model incorporates voltage, current and pulse-on-time during material removal to predict the temperature distribution on the workpiece as a result of single discharges in micro-EDM. It is assumed that the entire superheated area is ejected from the workpiece surface while only a small fraction of the molten area is expelled. For verification purposes, single discharge experiments using RC pulse generator are performed with pure tungsten as the electrode and AISI 4140 alloy steel as the workpiece. For the pulse-on-time range up to 1000 ns, the experimental and theoretical results are found to be in close agreement with average volume approximation errors of 2.7% and 6.6% for the anode and cathode, respectively

407

Metallurgical alterations in the surface of steel cavities machined by EDM  

Scientific Electronic Library Online (English)

Full Text Available The electrical discharge machining (EDM) is a process characterized by high thermal demands, which tend to cause metallurgical changes in the surface of the workpiece [1-2]. This work aims to conduct a discussion of metallurgical changes in the surface of cavities obtained by the process of EDM in t [...] he machining of steel. Several variables were employed, such as cavity depth, electrode geometry and technological parameters of the process. Thus, the goal was to identify the different metallurgical changes that can occur in the machined surfaces. The evaluation of these changes was made from metallographic analysis, measurements of microhardness and of the depth of the layer affected by process. The results of this work identified several metallurgical changes such as formation of white layer, hardness variation and change of microstructure. The occurrence of microcracks also was observed, especially in severe conditions. The greatest variations in results were caused by the change of technological parameters. However, the variation in cavity depth and the change of the electrode geometry also showed influence on the results.

Rodrigo Panosso, Zeilmann; Thiago, Vacaro; Fernando Moreira, Zanotto; Mariana, Czarnobay.

1541-15-01

408

Search for first generation leptoquark pair production in the electron + missing energy + jets final state  

CERN Document Server

We present a search for the pair production of first generation scalar leptoquarks (LQ) in data corresponding to an integrated luminosity of 5.4 fb$^{-1}$ collected with the D0 detector at the Fermilab Tevatron Collider in ppbar collisions at $\\sqrt{s}=1.96$ TeV. In the channel $LQ \\bar{LQ} \\rightarrow e\

Abazov, V

2011-01-01

409

Identifying quality improvement intervention publications - A comparison of electronic search strategies  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The evidence base for quality improvement (QI interventions is expanding rapidly. The diversity of the initiatives and the inconsistency in labeling these as QI interventions makes it challenging for researchers, policymakers, and QI practitioners to access the literature systematically and to identify relevant publications. Methods We evaluated search strategies developed for MEDLINE (Ovid and PubMed based on free text words, Medical subject headings (MeSH, QI intervention components, continuous quality improvement (CQI methods, and combinations of the strategies. Three sets of pertinent QI intervention publications were used for validation. Two independent expert reviewers screened publications for relevance. We compared the yield, recall rate, and precision of the search strategies for the identification of QI publications and for a subset of empirical studies on effects of QI interventions. Results The search yields ranged from 2,221 to 216,167 publications. Mean recall rates for reference publications ranged from 5% to 53% for strategies with yields of 50,000 publications or fewer. The 'best case' strategy, a simple text word search with high face validity ('quality' AND 'improv*' AND 'intervention*' identified 44%, 24%, and 62% of influential intervention articles selected by Agency for Healthcare Research and Quality (AHRQ experts, a set of exemplar articles provided by members of the Standards for Quality Improvement Reporting Excellence (SQUIRE group, and a sample from the Cochrane Effective Practice and Organization of Care Group (EPOC register of studies, respectively. We applied the search strategy to a PubMed search for articles published in 10 pertinent journals in a three-year period which retrieved 183 publications. Among these, 67% were deemed relevant to QI by at least one of two independent raters. Forty percent were classified as empirical studies reporting on a QI intervention. Conclusions The presented search terms and operating characteristics can be used to guide the identification of QI intervention publications. Even with extensive iterative development, we achieved only moderate recall rates of reference publications. Consensus development on QI reporting and initiatives to develop QI-relevant MeSH terms are urgently needed.

Rubenstein Lisa V

2011-08-01

410

New concept for a neutron electric dipole moment search using a pulsed beam  

Science.gov (United States)

A concept to search for a neutron electric dipole moment (nEDM) is presented, which employs a pulsed neutron beam instead of the established use of storable ultracold neutrons (UCN). The technique takes advantage of the high peak flux and the time structure of a next-generation pulsed spallation source like the planned European Spallation Source. It is demonstrated that the sensitivity for a nEDM can be improved by several orders of magnitude compared to the best beam experiments performed in the 1970s and can compete with the sensitivity of UCN experiments.

Piegsa, Florian M.

2013-10-01

411

New Concept for a Neutron Electric Dipole Moment Search using a Pulsed Beam  

CERN Document Server

A concept to search for a neutron electric dipole moment (nEDM) is presented, which employs a pulsed neutron beam instead of the nowadays established use of storable ultracold neutrons (UCN). The technique takes advantage of the high peak flux and the time structure of a next-generation pulsed spallation source like the planned European Spallation Source. It is demonstrated that the sensitivity for a nEDM can be improved by several orders of magnitude compared to the best beam experiments performed in the 1970's and can compete with the sensitivity of UCN experiments.

Piegsa, F M

2013-01-01

412

Proceedings of the International Conference on Educational Data Mining (EDM) (4th, Eindhoven, the Netherlands, July 6-8, 2011)  

Science.gov (United States)

The 4th International Conference on Educational Data Mining (EDM 2011) brings together researchers from computer science, education, psychology, psychometrics, and statistics to analyze large datasets to answer educational research questions. The conference, held in Eindhoven, The Netherlands, July 6-9, 2011, follows the three previous editions…

Pechenizkiy, Mykola; Calders, Toon; Conati, Cristina; Ventura, Sebastian; Romero, Cristobal; Stamper, John

2011-01-01

413

A Lower Bound on hadronic EDMs from CP Violation in D0-D0bar mixing in SUSY Alignment Models  

CERN Document Server

The SM predictions for CP violating effects in D meson systems are highly suppressed at the per mill level. Therefore, any experimental evidence for a sizable CP violation in D0-D0bar mixing would unambiguously point towards a New Physics (NP) signal. Within supersymmetric scenarios, the popular alignment models can naturally account for large, non-standard effects in D0-D0bar mixing. We demonstrate that, within alignment models, detectable CP violating effects in D0-D0bar mixing would unambiguously imply a lower bound for the electric dipole moment (EDM) of hadronic systems, like the neutron EDM and the mercury EDM, in the reach of future experimental sensitivities. The simultaneous evidence of CP violation in D meson systems together with non vanishing hadronic EDMs would strongly support the idea of SUSY alignment models and disfavour gauge-mediated SUSY breaking models, SUSY models with MFV and non-Abelian SUSY flavour models. As a byproduct of our analysis, we study the correlation between the time depen...

Altmannshofer, Wolfgang; Paradisi, Paride

2010-01-01

414

A lower bound on hadronic EDMs from CP violation in D0-D¯ mixing in SUSY alignment models  

Science.gov (United States)

The SM predictions for CP violating effects in D meson systems are highly suppressed at the per mill level. Therefore, any experimental evidence for a sizable CP violation in D0-Dbar0 mixing would unambiguously point towards a New Physics (NP) signal. Within supersymmetric scenarios, the popular alignment models can naturally account for large, non-standard effects in D0-Dbar0 mixing. We demonstrate that, within alignment models, detectable CP violating effects in D0-Dbar0 mixing would unambiguously imply a lower bound for the electric dipole moment (EDM) of hadronic systems, like the neutron EDM and the mercury EDM, in the reach of future experimental sensitivities. The simultaneous evidence of CP violation in D meson systems together with non-vanishing hadronic EDMs would strongly support the idea of SUSY alignment models and disfavour gauge-mediated SUSY breaking models, SUSY models with MFV and non-Abelian SUSY flavour models. As a byproduct of our analysis, we study the correlation between the time dependent CP asymmetry in decays to CP eigenstates Sf and the semileptonic asymmetry aSL both model independently and in SUSY alignment models.

Altmannshofer, Wolfgang; Buras, Andrzej J.; Paradisi, Paride

2010-05-01

415

Investigation of the removing process of cathode material in micro-EDM using an atomistic-continuum model  

Science.gov (United States)

In micro-electrical discharge machining (micro-EDM), the discharge duration is ultra-short, and both the electric action and the thermal action by the discharge channel play important roles in the removing process of cathode material. However, in most researches on the machining mechanism of micro-EDM, only the thermal action is concerned. In this article, a combined atomistic-continuum modeling method in which the two-temperature model and the molecular dynamics simulation model are integrated is used to construct the simulation model for cathode in single-discharge micro-EDM process. With this simulation model, removing processes of Cu cathode material in micro-EDM under pure thermal action, pure electric action and the combination of them are investigated in a simulative way. By analyzing evolutions of temperature, stress and micro-structure of material as well as the dynamical behaviors of material in the removing process, mechanisms of the cathode material removal and crater formation are revealed. In addition, the removing process of cathode material under the combination of pure thermal action and pure electric action is compared with those under the two pure actions respectively to analyze the interactive effect between the thermal action and the electric action.

Guo, Jianwen; Zhang, Guojun; Huang, Yu; Ming, Wuyi; Liu, Min; Huang, Hao

2014-10-01

416

Charm and beauty searches using electron-D0 azimuthal correlations and microvertexing techniques in STAR experiment at RHIC  

International Nuclear Information System (INIS)

The energy loss of heavy quarks in the hot and dense matter created at RHIC, can be used to probe the properties of the medium. Both charm and beauty quarks contribute to the non-photonic electrons through their semi-leptonic decays. It is essential to determine experimentally the relative contribution of charm and beauty quarks to understand the suppression of heavy flavors at high PT in central Au+Au collisions. The azimuthal angular correlations of non-photonic electrons with the reconstructed D0 allow to disentangle the contribution of charm and beauty and to reduce the background below the D0 invariant mass as well. We discuss the STAR measurement of non-photonic electron and D0 ? K? azimuthal correlations in p+p collisions at 200 GeV. Furthermore, we show results from the application of microvertexing techniques for charm and beauty searches in Cu+Cu and Au+Au collisions at 200 GeV using the information of the Silicon tracker of STAR.

417

Charm and beauty searches using electron-D{sup 0} azimuthal correlations and microvertexing techniques in STAR experiment at RHIC  

Energy Technology Data Exchange (ETDEWEB)

The energy loss of heavy quarks in the hot and dense matter created at RHIC, can be used to probe the properties of the medium. Both charm and beauty quarks contribute to the non-photonic electrons through their semi-leptonic decays. It is essential to determine experimentally the relative contribution of charm and beauty quarks to understand the suppression of heavy flavors at high P{sub T} in central Au+Au collisions. The azimuthal angular correlations of non-photonic electrons with the reconstructed D{sup 0} allow to disentangle the contribution of charm and beauty and to reduce the background below the D{sup 0} invariant mass as well. We discuss the STAR measurement of non-photonic electron and D{sup 0} {yields} K{pi} azimuthal correlations in p+p collisions at 200 GeV. Furthermore, we show results from the application of microvertexing techniques for charm and beauty searches in Cu+Cu and Au+Au collisions at 200 GeV using the information of the Silicon tracker of STAR.

Borowski, Witold, E-mail: witold.borowski@subatech.in2p3.fr [Laboratoire SUBATECH, 4 rue Alfred Kastler, BP 20722, 44307 Nantes cedex 3 (France)

2011-01-01

418

Electronics  

CERN Document Server

Although most people would scarcely be able to make it through the day without using some type of electronic device-computers, televisions, and MP3 players, to name a few-the inner workings of such devices remain a mystery to many. This insightful volume examines various components, such as electron tubes and semiconductors, that have been essential to electronics over the years, as well as the history of the field in general and its applications in everyday life.

Hollar, Sherman

2012-01-01

419

Electronics  

CERN Document Server

Electronics Theory and Practice introduces the key areas of analog electronics through practicals, worked examples and concise explanations. The author is a senior lecturer at De Montfort University and his approach is a proven way of teaching the essentials of electronics to groups with a variety of academic backgrounds. This is an ideal text for first year modules and HNC/D units - comprehensive, concise and affordable.

Mesias, Gerardo

2012-01-01

420

Searching for Dark Matter Signatures in the GLAST LAT Electron Flux  

Science.gov (United States)

We explored several viable scenarios of how LAT might observe DM, when the spectral feature is predicted to be observed in the HE electron flux It has been demonstrated elsewhere that LAT will be capable to detect HE electrons flux in energy range from 20 GeV to - 1 TeV with 520% energy resolution and good statistics If there is a DM-caused feature in the HE electron flux (in the range 20 GeV - 1 TeV), LAT will be the best current instrument to observe it!

Moiseev, Alexander; Profumo, Stefano

2008-01-01

421

Electrons  

International Nuclear Information System (INIS)

Fast electrons are used to produce isotopes for studying the cooper metabolism: Cu-64 in a cyclotron and Cu-67 in a linear accelerator. Localized electrons are responsible for the chemical and physiological characteristics of the trace elements. Studied are I, Cu, Co, Zn, Mo, Mn, Fe, Se, Mg. The Cu/Mo and Cu/Zn interactions are investigated. The levels of molybdenum, sulfate and zinc in the food are analysed. The role of the electrons in free radicals is discussed. The protection action of peroxidases and super oxidases against electron dangerous effect on normal physiology is also considered. Calculation of radiation damage and radiation protection is made. (author)

422

Search for Heavy Particles Decaying into Electron-Positron Pairs in ppbar Collisions  

Science.gov (United States)

We present results of searches for technirho (?T), techniomega (?T), and Z' particles, using the decay channels ?T,?T,Z'-->e+e-. The search is based on 124.8 pb-1 of data collected by the D0 detector at the Fermilab Tevatron during 1992-1996. In the absence of a signal, we set 95% C.L. upper limits on the cross sections for the processes ppbar-->?T,?T,Z'-->e+e- as a function of the mass of the decaying particle. For certain model parameters, we exclude the existence of degenerate ?T and ?T states with masses below about 200 GeV. We exclude a Z' with mass below 670 GeV, assuming that it has the same couplings to fermions as the Z boson.

Abazov, V. M.; Abbott, B.; Abdesselam, A.; Abolins, M.; Abramov, V.; Acharya, B. S.; Adams, D. L.; Adams, M.; Ahmed, S. N.; Alexeev, G. D.; Alves, G. A.; Amos, N.; Anderson, E. W.; Baarmand, M. M.; Babintsev, V. V.; Babukhadia, L.; Bacon, T. C.; Baden, A.; Baldin, B.; Balm, P. W.; Banerjee, S.; Barberis, E.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bauer, D.; Bean, A.; Begel, M.; Belyaev, A.; Beri, S. B.; Bernardi, G.; Bertram, I.; Besson, A.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Bhattacharjee, M.; Blazey, G.; Blessing, S.; Boehnlein, A.; Bojko, N. I.; Borcherding, F.; Bos, K.; Brandt, A.; Breedon, R.; Briskin, G.; Brock, R.; Brooijmans, G.; Bross, A.; Buchholz, D.; Buehler, M.; Buescher, V.; Burtovoi, V. S.; Butler, J. M.; Canelli, F.; Carvalho, W.; Casey, D.; Casilum, Z.; Castilla-Valdez, H.; Chakraborty, D.; Chan, K. M.; Chekulaev, S. V.; Cho, D. K.; Choi, S.; Chopra, S.; Christenson, J. H.; Chung, M.; Claes, D.; Clark, A. R.; Cochran, J.; Coney, L.; Connolly, B.; Cooper, W. E.; Coppage, D.; Cummings, M. A.; Cutts, D.; Davis, G. A.; Davis, K.; de, K.; de Jong, S. J.; del Signore, K.; Demarteau, M.; Demina, R.; Demine, P.; Denisov, D.; Denisov, S. P.; Desai, S.; Diehl, H. T.; Diesburg, M.; di Loreto, G.; Doulas, S.; Draper, P.; Ducros, Y.; Dudko, L. V.; Duensing, S.; Duflot, L.; Dugad, S. R.; Dyshkant, A.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Engelmann, R.; Eno, S.; Eppley, G.; Ermolov, P.; Eroshin, O. V.; Estrada, J.; Evans, H.; Evdokimov, V. N.; Fahland, T.; Feher, S.; Fein, D.; Ferbel, T.; Filthaut, F.; Fisk, H. E.; Fisyak, Y.; Flattum, E.; Fleuret, F.; Fortner, M.; Frame, K. C.; Fuess, S.; Gallas, E.; Galyaev, A. N.; Gao, M.; Gavrilov, V.; Genik, R. J.; Genser, K.; Gerber, C. E.; Gershtein, Y.; Gilmartin, R.; Ginther, G.; Gómez, B.; Gómez, G.; Goncharov, P. I.; González Solís, J. L.; Gordon, H.; Goss, L. T.; Gounder, K.; Goussiou, A.; Graf, N.; Graham, G.; Grannis, P. D.; Green, J. A.; Greenlee, H.; Grinstein, S.; Groer, L.; Grünendahl, S.; Gupta, A.; Gurzhiev, S. N.; Gutierrez, G.; Gutierrez, P.; Hadley, N. J.; Haggerty, H.; Hagopian, S.; Hagopian, V.; Hall, R. E.; Hanlet, P.; Hansen, S.; Hauptman, J. M.; Hays, C.; Hebert, C.; Hedin, D.; Heinson, A. P.; Heintz, U.; Heuring, T.; Hildreth, M. D.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Huang, Y.; Illingworth, R.; Ito, A. S.; Jaffré, M.; Jain, S.; Jesik, R.; Johns, K.; Johnson, M.; Jonckheere, A.; Jones, M.; Jöstlein, H.; Juste, A.; Kahn, S.; Kajfasz, E.; Kalinin, A. M.; Karmanov, D.; Karmgard, D.; Kehoe, R.; Kharchilava, A.; Kim, S. K.; Klima, B.; Knuteson, B.; Ko, W.; Kohli, J. M.; Kostritskiy, A. V.; Kotcher, J.; Kotwal, A. V.; Kozelov, A. V.; Kozlovsky, E. A.; Krane, J.; Krishnaswamy, M. R.; Krivkova, P.; Krzywdzinski, S.; Kubantsev, M.; Kuleshov, S.; Kulik, Y.; Kunori, S.; Kupco, A.; Kuznetsov, V. E.; Landsberg, G.; Leflat, A.; Leggett, C.; Lehner, F.; Li, J.; Li, Q. Z.; Lima, J. G.; Lincoln, D.; Linn, S. L.; Linnemann, J.; Lipton, R.; Lucotte, A.; Lueking, L.; Lundstedt, C.; Luo, C.; Maciel, A. K.; Madaras, R. J.; Malyshev, V. L.; Manankov, V.; Mao, H. S.; Marshall, T.; Martin, M. I.; Martin, R. D.; Mauritz, K. M.; May, B.; Mayorov, A. A.; McCarthy, R.; McDonald, J.; McMahon, T.; Melanson, H. L.; Merkin, M.; Merritt, K. W.; Miao, C.; Miettinen, H.; Mihalcea, D.; Mishra, C. S.; Mokhov, N.; Mondal, N. K.; Montgomery, H. E.; Moore, R. W.; Mostafa, M.; da Motta, H.; Nagy, E.; Nang, F.; Narain, M.; Narasimham, V. S.; Neal, H. A.; Negret, J. P.; Negroni, S.; Nunnemann, T.; O'Neil, D.; Oguri, V.; Olivier, B.; Oshima, N.; Padley, P.; Pan, L. J.; Papageorgiou, K.; Para, A.; Parashar, N.; Partridge, R.; Parua, N.; Paterno, M.; Patwa, A.; Pawlik, B.; Perkins, J.; Peters, M.; Peters, O.; Pétroff, P.; Piegaia, R.; Piekarz, H.; Pope, B. G.; Popkov, E.; Prosper, H. B.; Protopopescu, S.; Qian, J.; Raja, R.; Rajagopalan, S.; Ramberg, E.; Rapidis, P. A.; Reay, N. W.; Reucroft, S.; Rha, J.; Ridel, M.; Rijssenbeek, M.; Rockwell, T.; Roco, M.; Rubinov, P.; Ruchti, R.; Rutherfoord, J.; Sabirov, B. M.; Santoro, A.; Sawyer, L.; Schamberger, R. D.; Schellman, H.; Schwartzman, A.; Sen, N.; Shabalina, E.; Shivpuri, R. K.; Shpakov, D.; Shupe, M.; Sidwell, R. A.; Simak, V.; Singh, H.; Singh, J. B.; Sirotenko, V.; Slattery, P.; Smith, E.; Smith, R. P.; Snihur, R.; Snow, G. R.; Snow, J.; Snyder, S.; Solomon, J.; Sorín, V.; Sosebee, M.; Sotnikova, N.; Soustruznik, K.; Souza, M.; Stanton, N. R.; Steinbrück, G.; Stephens, R. W.; Stichelbaut, F.; Stoker, D.; Stolin, V.; Stoyanova, D. A.; Strauss, M.; Strovink, M.; Stutte, L.; Sznajder, A.; Taylor, W.; Tentindo-Repond, S.; Tripathi, S. M.; Trippe, T. G.; Turcot, A. S.; Tuts, P. M.; van Gemmeren, P.; Vaniev, V.; van Kooten, R.; Varelas, N.; Vertogradov, L. S.; Volkov, A. A.

2001-08-01

423

Search for heavy particles decaying into electron-positron pairs in pp collisions.  

Science.gov (United States)

We present results of searches for technirho (rho(T)), techniomega (omega(T)), and Z' particles, using the decay channels rho(T),omega(T),Z'-->e(+)e(-). The search is based on 124.8 pb(-1) of data collected by the D0 detector at the Fermilab Tevatron during 1992-1996. In the absence of a signal, we set 95% C.L. upper limits on the cross sections for the processes pp-->rho(T),omega(T),Z'-->e(+)e(-) as a function of the mass of the decaying particle. For certain model parameters, we exclude the existence of degenerate rho(T) and omega(T) states with masses below about 200 GeV. We exclude a Z' with mass below 670 GeV, assuming that it has the same couplings to fermions as the Z boson. PMID:11497822

Abazov, V M; Abbott, B; Abdesselam, A; Abolins, M; Abramov, V; Acharya, B S; Adams, D L; Adams, M; Ahmed, S N; Alexeev, G D; Alves, G A; Amos, N; Anderson, E W; Baarmand, M M; Babintsev, V V; Babukhadia, L; Bacon, T C; Baden, A; Baldin, B; Balm, P W; Banerjee, S; Barberis, E; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Bean, A; Begel, M; Belyaev, A; Beri, S B; Bernardi, G; Bertram, I; Besson, A; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Bhattacharjee, M; Blazey, G; Blessing, S; Boehnlein, A; Bojko, N I; Borcherding, F; Bos, K; Brandt, A; Breedon, R; Briskin, G; Brock, R; Brooijmans, G; Bross, A; Buchholz, D; Buehler, M; Buescher, V; Burtovoi, V S; Butler, J M; Canelli, F; Carvalho, W; Casey, D; Casilum, Z; Castilla-Valdez, H; Chakraborty, D; Chan, K M; Chekulaev, S V; Cho, D K; Choi, S; Chopra, S; Christenson, J H; Chung, M; Claes, D; Clark, A R; Cochran, J; Coney, L; Connolly, B; Cooper, W E; Coppage, D; Cummings, M A; Cutts, D; Davis, G A; Davis, K; De, K; de Jong, S J; Del Signore, K; Demarteau, M; Demina, R; Demine, P; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Di Loreto, G; Doulas, S; Draper, P; Ducros, Y; Dudko, L V; Duensing, S; Duflot, L; Dugad, S R; Dyshkant, A; Edmunds, D; Ellison, J; Elvira, V D; Engelmann, R; Eno, S; Eppley, G; Ermolov, P; Eroshin, O V; Estrada, J; Evans, H; Evdokimov, V N; Fahland, T; Feher, S; Fein, D; Ferbel, T; Filthaut, F; Fisk, H E; Fisyak, Y; Flattum, E; Fleuret, F; Fortner, M; Frame, K C; Fuess, S; Gallas, E; Galyaev, A N; Gao, M; Gavrilov, V; Genik, R J; Genser, K; Gerber, C E; Gershtein, Y; Gilmartin, R; Ginther, G; Gómez, B; Gómez, G; Goncharov, P I; González Solís, J L; Gordon, H; Goss, L T; Gounder, K; Goussiou, A; Graf, N; Graham, G; Grannis, P D; Green, J A; Greenlee, H; Grinstein, S; Groer, L; Grünendahl, S; Gupta, A; Gurzhiev, S N; Gutierrez, G; Gutierrez, P; Hadley, N J; Haggerty, H; Hagopian, S; Hagopian, V; Hall, R E; Hanlet, P; Hansen, S; Hauptman, J M; Hays, C; Hebert, C; Hedin, D; Heinson, A P; Heintz, U; Heuring, T; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Huang, Y; Illingworth, R; Ito, A S; Jaffré, M; Jain, S; Jesik, R; Johns, K; Johnson, M; Jonckheere, A; Jones, M; Jöstlein, H; Juste, A; Kahn, S; Kajfasz, E; Kalinin, A M; Karmanov, D; Karmgard, D; Kehoe, R; Kharchilava, A; Kim, S K; Klima, B; Knuteson, B; Ko, W; Kohli, J M; Kostritskiy, A V; Kotcher, J; Kotwal, A V; Kozelov, A V; Kozlovsky, E A; Krane, J; Krishnaswamy, M R; Krivkova, P; Krzywdzinski, S; Kubantsev, M; Kuleshov, S; Kulik, Y; Kunori, S; Kupco, A; Kuznetsov, V E; Landsberg, G; Leflat, A; Leggett, C; Lehner, F; Li, J; Li, Q Z; Lima, J G; Lincoln, D; Linn, S L; Linnemann, J; Lipton, R; Lucotte, A; Lueking, L; Lundstedt, C; Luo, C; Maciel, A K; Madaras, R J; Malyshev, V L; Manankov, V; Mao, H S; Marshall, T; Martin, M I; Martin, R D; Mauritz, K M; May, B; Mayorov, A A; McCarthy, R; McDonald, J; McMahon, T; Melanson, H L; Merkin, M; Merritt, K W; Miao, C; Miettinen, H; Mihalcea, D; Mishra, C S; Mokhov, N; Mondal, N K; Montgomery, H E; Moore, R W; Mostafa, M; da Motta, H; Nagy, E; Nang, F; Narain, M; Narasimham, V S; Neal, H A; Negret, J P; Negroni, S; Nunnemann, T; O'Neil, D; Oguri, V; Olivier, B; Oshima, N; Padley, P; Pan, L J; Papageorgiou, K; Para, A; Parashar, N; Partridge, R; Parua, N; Paterno, M; Patwa, A; Pawlik, B; Perkins, J; Peters, M; Peters, O; Pétroff, P; Piegaia, R; Piekarz, H; Pope, B G; Popkov, E; Prosper, H B; Protopopescu, S; Qian, J; Raja, R; Rajagopalan, S; Ramberg, E; Rapidis, P A; Reay, N W; Reucroft, S; Rha, J; Ridel, M; Rijssenbeek, M; Rockwell, T; Roco, M; Rubinov, P; Ruchti, R; Rutherfoord, J; Sabirov, B M; Santoro, A; Sawyer, L; Schamberger, R D; Schellman, H; Schwartzman, A; Sen, N; Shabalina, E; Shivpuri, R K; Shpakov, D; Shupe, M; Sidwell, R A; Simak, V; Singh, H; Singh, J B; Sirotenko, V; Slattery, P; Smith, E; Smith, R P; Snihur, R; Snow, G R; Snow, J; Snyder, S; Solomon, J; Sorín, V; Sosebee, M; Sotnikova, N; Soustruznik, K; Souza, M; Stanton, N R; Steinbrück, G; Stephens, R W; Stichelbaut, F; Stoker, D; Stolin, V; Stoyanova, D A; Strauss, M; Strovink, M; Stutte, L; Sznajder, A; Taylor, W; Tentindo-Repond, S; Tripathi, S M; Trippe, T G; Turcot, A S; Tuts, P M; van Gemmeren, P; Vaniev, V; Van Kooten, R; Varelas, N; Vertogradov, L S; Volkov, A A; Vorobiev, A P; Wahl, H D; Wang, H; Wang, Z M; Warchol, J; Watts, G; Wayne, M; Weerts, H; White, A; White, J T; Whiteson, D; Wightman, J A; Wijngaarden, D A; Willis, S; Wimpenny, S J; Womersley, J; Wood, D R; Yamada, R; Yamin, P; Yasuda, T; Yatsunenko, Y A; Yip, K; Youssef, S; Yu, J; Yu, Z; Zanabria, M; Zheng, H; Zhou, Z; Zielinski, M; Zieminska, D; Zieminski, A; Zutshi, V; Zverev, E G; Zylberstejn, A

2001-08-01

424

Search for heavy particles decaying into electron-positron pairs in p-pbar collisions  

CERN Document Server

We present results of searches for technirho, techniomega, and Z' particles, using the decay channels technirho, techniomega, Z' -> e+e-. The search is based on 124.8 pb-1 of data collected by the D0 detector at the Fermilab Tevatron during 1992-1996. In the absence of a signal, we set 95% C.L. upper limits on the cross sections for the processes p pbar -> technirho, techniomega, Z' -> e+e- as a function of the mass of the decaying particle. For certain model parameters, we exclude the existence of degenerate technirho and techniomega states with masses below about 200 GeV. We exclude a Z' with mass below 670 GeV, assuming that it has the same couplings to fermions as the Z boson.

Abazov, V M; Abdesselam, A; Abolins, M; Abramov, V; Acharya, B S; Adams, D L; Adams, M; Ahmed, S N; Alexeev, G D; Alves, G A; Amos, N; Anderson, E W; Baarmand, M M; Babintsev, V V; Babukhadia, L R; Bacon, Trevor C; Baden, A; Baldin, B Yu; Balm, P W; Todorova-Nová, S; Barberis, E; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Bean, A; Begel, M; Belyaev, A; Beri, S B; Bernardi, G; Bertram, I; Besson, A; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Bhattacharjee, M; Blazey, G C; Blessing, S; Böhnlein, A; Bozhko, N; Borcherding, F; Bos, Kors; Brandt, A; Breedon, R; Briskin, G M; Brock, R; Brooijmans, G; Bross, A; Buchholz, D; Bühler, M; Büscher, V; Burtovoi, V S; Butler, J M; Canelli, F; Carvalho, W S; Casey, D; Casilum, Z; Castilla-Valdez, H; Chakraborty, D; Chan, K M; Chekulaev, S V; Cho, D K; Choi, S; Chopra, S; Christenson, J H; Chung, M; Claes, D; Clark, A R; Cochran, J; Coney, L; Connolly, B; Cooper, W E; Coppage, D; Cummings, M A C; Cutts, D; Davis, G A; Davis, K; De, K; De Jong, S J; Del Signore, K; Demarteau, M; Demina, R; Demine, P; Denisov, D S; Denisov, S P; Desai, S V; Diehl, H T; Diesburg, M; DiLoreto, G; Doulas, S; Draper, P; Ducros, Y; Dudko, L V; Duensing, S; Duflot, L; Dugad, S R; Dyshkant, A; Edmunds, D; Ellison, J; Elvira, V D; Engelmann, R; Eno, S; Eppley, G; Ermolov, P; Eroshin, O V; Estrada, J; Evans, H; Evdokimov, V N; Fahland, T; Fehér, S; Fein, D; Ferbel, T; Filthaut, Frank; Fisk, H E; Fisyak, Yu; Flattum, E M; Fleuret, F; Fortner, M R; Frame, K C; Fuess, S; Gallas, E; Galjaev, A N; Gao, M; Gavrilov, V; Genik, R J; Genser, K; Gerber, C E; Gershtein, Yu; Gilmartin, R; Ginther, G; Gómez, B; Gómez, G; Goncharov, P I; González-Solis, J L; Gordon, H; Goss, L T; Gounder, K; Goussiou, A; Graf, N; Graham, G; Grannis, P D; Green, J A; Greenlee, H; Grinstein, S; Groer, L S; Grünendahl, S; Sen-Gupta, A; Gurzhev, S N; Gutíerrez, G; Gutíerrez, P; Hadley, N J; Haggerty, H; Hagopian, S L; Hagopian, V; Hall, R E; Hanlet, P; Hansen, S; Hauptman, J M; Hays, C; Hebert, C; Hedin, D; Heinson, A P; Heintz, U; Heuring, T C; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Huang, Y; Illingworth, R; Ito, A S; Jaffré, M; Jain, S; Jesik, R; Johns, K; Johnson, M; Jonckheere, A; Jones, M; Jöstlein, H; Juste, A; Kahn, S; Kajfasz, E; Kalinin, A M; Karmanov, D E; Karmgard, D J; Kehoe, R; Kharchilava, A I; Kim, S K; Klima, B; Knuteson, B; Ko, W; Kohli, J M; Kostritskii, A V; Kotcher, J; Kotwal, A V; Kozelov, A V; Kozlovskii, E A; Krane, J; Krishnaswamy, M R; Krivkova, P; Krzywdzinski, S; Kubantsev, M A; Kuleshov, S; Kulik, Y; Kunori, S; Kupco, A; Kuznetsov, V E; Landsberg, G L; Leflat, A; Leggett, C; Lehner, F; Li, J; Li, Q Z; Lima, J G R; Lincoln, D; Linn, S L; Linnemann, J T; Lipton, R; Lucotte, A; Lueking, L H; Lundstedt, C; Luo, C; Maciel, A K A; Madaras, R J; Malyshev, V L; Manankov, V; Mao, H S; Marshall, T; Martin, M I; Martin, R D; Mauritz, K M; May, B; Mayorov, A A; McCarthy, R; McDonald, J; McMahon, T; Melanson, H L; Merkin, M; Merritt, K W B; Miao, C; Miettinen, H; Mihalcea, D; Mishra, C S; Mokhov, N V; Mondal, N K; Montgomery, H E; Moore, R W; Mostafa, M A; Da Motta, H; Nagy, E; Nang, F; Narain, M; Narasimham, V S; Neal, H A; Negret, J P; Negroni, S; Nunnemann, T; O'Neil, D C; Oguri, V; Olivier, B; Oshima, N; Padley, P; Pan, L J; Papageorgiou, K; Para, A; Parashar, N; Partridge, R; Parua, N; Paterno, M; Patwa, A; Pawlik, B; Perkins, J; Peters, M; Peters, O; Petroff, P; Piegaia, R; Piekarz, H; Pope, B G; Popkov, E; Prosper, H B; Protopopescu, S D; Qian, J; Raja, R; Rajagopalan, S; Ramberg, E; Rapidis, P A; Reay, N W; Reucroft, S; Rha, J; Ridel, M; Rijssenbeek, M; Rockwell, T; Roco, M T; Rubinov, P; Ruchti, R C; Rutherfoord, John P; Sabirov, B M; Santoro, A F S; Sawyer, L; Schamberger, R D; Schellman, H; Schwartzman, A; Sen, N; Shabalina, E; Shivpuri, R K; Shpakov, D; Shupe, M A; Sidwell, R A; Simák, V; Singh, H; Singh, J B; Sirotenko, V I; Slattery, P F; Smith, E; Smith, R P; Snihur, R; Snow, G A; Snow, J; Snyder, S; Solomon, J; Sorin, V; Sosebee, M; Sotnikova, N; Soustruznik, K; Souza, M; Stanton, N R; Steinbruck, G; Stephens, R W; Stichelbaut, F; Stoker, D; Stolin, V; Stoyanova, D A; Strauss, M; Strovink, M; Stutte, L; Sznajder, A; Taylor, W; Tentindo-Repond, S; Tripathi, S M; Trippe, T G; Turcot, A S; Tuts, P M; Van Gemmeren, P; Vaniev, V; Van Kooten, R; Varelas, N; Vertogradov, L S; Volkov, A A; Vorobev, A P; Wahl, H D; Wang, H; Wang, Z M; Warchol, J; Watts, G; Wayne, M; Weerts, H; White, A; White, J T; Whiteson, D; Wightman, J A; Wijngaarden, D A; Willis, S; Wimpenny, S J; Womersley, J; Wood, D R; Yamada, R; Yamin, P; Yasuda, T; Yatsunenko, Yu A; Yip, K; Youssef, S; Yu, J; Yu, Z; Zanabria, M E; Zheng, H; Zhou, Z; Zielinski, M; Zieminska, D; Zieminski, A; Zutshi, V; Zverev, E G; Zylberstejn, A

2001-01-01

425

Energies, transition rates, and electron electric-dipole-moment enhancement factors for Ce IV and Pr V  

International Nuclear Information System (INIS)

Energies, transition rates, and electron electric-dipole-moment (EDM) enhancement factors are calculated for low-lying states of Ce IV and Pr V using relativistic many-body perturbation theory. This study is related to recent investigations of the more complicated Gd IV ion, which is promising for electron EDM experiments. The ions Ce IV and Pr V both have a single valence electron, permitting one to carry out reliable ab initio calculations of energy levels, transition rates, and other atomic properties using well-developed computational methods

426

Search for pair production of the scalar top quark in the electron-muon final state  

CERN Document Server

We report the result of a search for the pair production of the lightest supersymmetric partner of the top quark ($\\tilde{t}_1$) in $p\\bar{p}$ collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider corresponding to an integrated luminosity of 5.4 fb$^{-1}$. The scalar top quarks are assumed to decay into a $b$ quark, a charged lepton, and a scalar neutrino ($\\tilde{\

Abazov, V M; Abolins, M; Acharya, B S; Adams, M; Adams, T; Alexeev, G D; Alkhazov, G; Altona, A; Alverson, G; Alves, G A; Ancu, L S; Aoki, M; Arnoud, Y; Arov, M; Askew, A; \\degAsman, B; Atramentov, O; Avila, C; BackusMayes, J; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barberis, E; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bazterra, V; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Blazey, G; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brandt, O; Brock, R; Brooijmans, G; Bross, A; Brown, D; Brown, J; Bu, X B; Buchholz, D; Buehler, M; Buescher, V; Bunichev, V; Burdinb, S; Burnett, T H; Buszello, C P; Calpas, B; Camacho-Pérez, E; Carrasco-Lizarraga, M A; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Chen, G; Chevalier-Théry, S; Cho, D K; Cho, S W; Choi, S; Choudhary, B; Christoudias, T; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M -C; Croc, A; Cutts, D; ?wiok, M; Das, A; Davies, G; De, K; de Jong, S J; De La Cruz-Burelo, E; Déliot, F; Demarteau, M; Demina, 47 R; Denisov, D; Denisov, S P; Desai, S; DeVaughan, K; Diehl, H T; Diesburg, M; Dominguez, A; Dorland, T; Dubey, A; Dudko, L V; Duggan, D; Duperrin, A; Dutt, S; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Evans, H; Evdokimov, A; Evdokimov, V N; Facini, G; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fuess, S; Gadfort, T; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Geng, W; Gerbaudo, D; Gerber, C E; Gershtein, Y; Ginther, G; Golovanov, G; Goussiou, A; Grannis, P D; Greder, S; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J -F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haasc, A; Hagopian, S; Haley, J; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Head, T; Hebbeker, T; Hedin, D; Hegab, H; Heinson, A P; Heintz, U; Hensel, C; La Cruz, I Heredia-De; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hossain, S; Hubacek, Z; Huske, N; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jamin, D; Jesik, R; Johns, K; Johnson, M; Johnston, D; Jonckheere, A; Jonsson, P; Joshi, J; Justed, A; Kaadze, K; Kajfasz, E; Karmanov, D; Kasper, P A; Katsanos, I; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Khatidze, D; Kirby, M H; Kohli, J M; Kozelov, A V; Kraus, J; Kumar, A; Kupco, A; Kur?a, T; Kuzmin, V A; Kvita, J; Lammers, S; Landsberg, G; Lebrun, P; Lee, H S; Lee, S W; Lee, W M; Lellouch, J; Li, L; Li, Q Z; Lietti, S M; Lim, J K; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajicek, M; Love, P; Lubatti, H J; Luna-Garciae, R; Lyon, A L; Maciel, A K A; Mackin, D; Madar, R; Magaña-Villalba, R; Malik, S; Malyshev, V L; Maravin, Y; Martínez-Ortega, J; McCarthy, R; McGivern, C L; Meijer, M M; Melnitchouk, A; Menezes, D; Mercadante, P G; Merkin, M; Meyer, A; Meyer, J; Mondal, N K; Muanza, G S; Mulhearn, M; Nagy, E; Naimuddin, M; Narain, M; Nayyar, R; Neal, H A; Negret, J P; Neustroev, P; Novaes, S F; Nunnemann, T; Obrant, G; Orduna, J; Osman, N; Osta, J; Garzón, G J Otero y; Owen, M; Padilla, M; Pangilinan, M; Parashar, N; Parihar, V; Park, S K; Parsons, J; Partridgec, R; Parua, N; Patwa, A; Penning, B; Perfilov, M; Peters, K; Peters, Y; Petrillo, G; Pétroff, P; Piegaia, R; Piper, J; Pleier, M -A; Podesta-Lermaf, P L M; Podstavkov, V M; Pol, M -E; Polozov, P; Popov, A V; Prewitt, M; Price, D; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rangel, M S; Ranjan, K; Ratoff, P N; Razumov, I; Renkel, P; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Rominsky, M; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Sanghi, B; Santos, A S; Savage, G; Sawyer, L; Scanlon, T; Schamberger, R D; Scheglov, Y; Schellman, H; Schliephake, T; Schlobohm, S; Schwanenberger, C; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shary, V; Shchukin, A A; Shivpuri, R K; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Smith, K J; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Spurlock, B; Stark, J; Stolin, V; Stoyanova, D A; Strauss, E; Strauss, M; Strom, D; Stutte, L; Svoisky, P; Takahashi, M; Tanasijczuk, A; Taylor, W; Titov, M; Tokmenin, V V; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Uvarov, L; Uzunyan, S Uvarov S; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verdier, P

2010-01-01

427

Design for a fountain of YbF molecules to measure the electron's electric dipole moment  

International Nuclear Information System (INIS)

We propose an experiment to measure the electric dipole moment (EDM) of the electron using ultracold YbF molecules. The molecules are produced as a thermal beam by a cryogenic buffer gas source, and brought to rest in an optical molasses that cools them to the Doppler limit or below. The molecular cloud is then thrown upward to form a fountain in which the EDM of the electron is measured. A non-zero result would be unambiguous proof of new elementary particle interactions, beyond the standard model. (paper)

428

Design for a fountain of YbF molecules to measure the electron's electric dipole moment  

Science.gov (United States)

We propose an experiment to measure the electric dipole moment (EDM) of the electron using ultracold YbF molecules. The molecules are produced as a thermal beam by a cryogenic buffer gas source, and brought to rest in an optical molasses that cools them to the Doppler limit or below. The molecular cloud is then thrown upward to form a fountain in which the EDM of the electron is measured. A non-zero result would be unambiguous proof of new elementary particle interactions, beyond the standard model.

Tarbutt, M. R.; Sauer, B. E.; Hudson, J. J.; Hinds, E. A.

2013-05-01

429

Search of prompt electrons in the NA14 photoproduction experiment at the CERN  

International Nuclear Information System (INIS)

The purpose of this thesis is to isolate a prompt electron signal from the data of the NA14 photoproduction experiment at CERN. For that aim, a fast data filtering program has been developed. In order to have a good understanding of the electrons behaviour in the electromagnetic calorimeter, electrons from photon conversion were selected. The observation of events with a reconstructed psi and the sharing between the different psi production mechanism leads to a clear excess of the inelastic process relative to a QCD theoretical expectation. The prompt electrons measurement method, when applied to events obtained from a ?- beam, does not give any evidence for a signal. With incident photons, a strong signal is seen which cannot been explained by the Bethe Heitler mechanism and psi production alone. This signal is stronger than the photon-gluon fusion model prediction

430

Search for new candidates for the neutrino-oriented mass determination by electron-capture  

CERN Multimedia

This proposal is part of an extended program dedicated to the neutrino-mass determination in the electron-capture sector, which aims at ultra-precise mass measurements by Penning traps in combination with cryogenic micro-calorimetry for atomic de-excitation measurements. Here, precise mass measurements with ISOLTRAP are proposed for the orbital electron-capture nuclides $^{194}$Hg and $^{2o2}$Pb, as well as their daughters, with the goal to determine accurately their Q-values. These values are expected to be the smallest ones among a great variety of known electron-capture precursors. Therefore, these nuclides are strong candidates for an improved electron-neutrino mass determination. We ask for 8 shifts of on-line beam at ISOLDE for mass measurements of $^{194}$Hg, $^{194}$ Au, $^{2o2}$Pb, and $^{2o2}$Tl at ISOLTRAP.

Herfurth, F; Boehm, C; Blaum, K; Lunney, D; Beck, D

2008-01-01

431

Search for interference effects in electron impact ionization of aligned hydrogen molecules  

OpenAIRE

Abstract Five-fold differential cross sections (5DCS) for electron impact ionization of a diatomic molecule have been explored experimentally as a function of molecular alignment. Using H 2 as a test system we exploited dissociative ionization by 200 eV electrons to obtain the alignment of the internuclear axis. Separation of groundstate ionization from autoionization is discussed. 5DCS are investigated for the direct channel and found to be in good agreement with M3DW calculations discard...

Senftleben, A.; Pflu?ger, T.; Ren, X.; Al-hagan, O.; Najjari, B.; Madison, D.; Dorn, A.; Ullrich, J.

2010-01-01

432

Exploring User Interfaces for Search and Content Based Clinical Decision Support in Electronic Health Record Systems  

OpenAIRE

Both electronic health records (EHR) and clinical decision support (CDS)are each important attributions to clinicans and clinical workflow. Elec-tronic health records provide clinicans with crucial patient information atthe point of care, while clinical decision support gives well-founded and well-documented clinical recommendations at the point of decision making.This thesis explores how patient information from EHRs could be utilized as abasis for better and more effective decision support....

Perry, Alexander

2013-01-01

433

Limit on the electron electric dipole moment in gadolinium-iron garnet.  

Science.gov (United States)

A new method for the detection of the electron electric dipole moment (EDM) using a solid is described. The method involves the measurement of a voltage induced across the solid by the alignment of the sample's magnetic dipoles in an applied magnetic field, H. A first application of the method to GdIG has resulted in a limit on the electron EDM of 5 x 10(-24)e cm, which is a factor of 40 below the limit obtained from the only previous solid-state EDM experiment. The result is limited by the imperfect discrimination of an unexpectedly large voltage that is even upon the reversal of the sample magnetization. PMID:16384457

Heidenreich, B J; Elliott, O T; Charney, N D; Virgien, K A; Bridges, A W; McKeon, M A; Peck, S K; Krause, D; Gordon, J E; Hunter, L R; Lamoreaux, S K

2005-12-16

434

Neutron and electron electric dipole moment in N=1 supergravity unification  

International Nuclear Information System (INIS)

An analysis of the neutron EDM and of the electron EDM in minimal N=1 supergravity unification with two CP-violating phases is given. For the neutron the analysis includes the complete one loop gluino, chargino, and neutralino exchange diagrams for the electric dipole and the chromoelectric dipole operators, and also the contribution of the purely gluonic dimension-six operator. It is shown that there exist significant regions in the six-dimensional parameter space of the model where cancellations between the gluino and the chargino exchanges reduce the electric and the chromoelectric contributions, and further cancellations among the electric, the chromoelectric, and the purely gluonic parts lead to a dramatic lowering of the neutron EDM sometimes below the electron EDM value. This phenomenon gives a new mechanism, i.e., that of internal cancellations, for the suppression of the neutron EDM in supersymmetric theories. The cancellation mechanism can significantly reduce the severe fine-tuning problem associated with CP-violating phases in SUSY and SUGRA unified models. copyright 1997 The American Physical Society

435

Ozone absorption spectroscopy in search of low-lying electronic states  

Science.gov (United States)

A spectrometer capable of detecting ozone absorption features 9 orders of magnitude weaker than the Hartley band has been employed to investigate the molecule's near-infrared absorption spectrum. At this sensitivity a wealth of information on the low-lying electronically excited states often believed to play a role in atmospheric chemistry is available in the form of vibrational and rotational structure. We have analyzed these spectra using a combination of digital filtering and isotope substitution and find evidence for three electronically excited states below 1.5 eV. The lowest of these states is metastable, bound by approximately 0.1 eV and probably the (3)A2 rather than the (3)B2 state. Its adiabatic electronic energy is 1.24 +/- 0.01 eV, slightly above the dissociation energy of the ground state. Two higher states, at 1.29 +/- 0.03 and 1.48 +/- 0.03 eV are identified as the (3)B2 and the (3)B1, respectively. Combined with other recent theoretical and experimental data on the low-lying electronic states of ozone, these results imply that these are, in fact, the lowest three excited states; that is, there are no electronically excited states of ozone lying below the energy of O(3P) + O2((3)Sigma(-), v = 0). Some of the implications for atmospheric chemistry are considered.

Anderson, S. M.; Mauersberger, K.

1995-01-01

436

BEHAVIOUR OF COPPER AND ALUMINIUM ELECTRODES ON EDM OF EN-8 ALLOY STEEL  

Directory of Open Access Journals (Sweden)

Full Text Available Electrical discharge machining (EDM has been recognized as an efficient production method for precision machining of electrically conducting hardened materials. Copper and aluminium are used as electrode materials in this process with Kerosene oil as the dielectric medium. In this work, the behavior of copper and aluminium electrodes on electric discharge machining of EN-8 alloy steel had been studied. Keeping all other machining parameters same, the hardened work material was machined with the two electrodes at different values of peak current, pulse-on time & duty factor according to 23 full factorial design. It has been found that copper shows better results than aluminium in term of surface finish (?m in same dielectric media. Therefore, copper is recommended as a good electrode material.

DHANANJAY PRADHAN

2011-07-01

437

SQUID magnetometry for the cryoEDM experiment-Tests at LSBB  

International Nuclear Information System (INIS)

High precision magnetometry is an essential requirement of the cryoEDM experiment at the Institut Laue-Langevin, Grenoble. We have developed a SQUID system for this purpose, however tests done in Oxford have been limited by the noisy electromagnetic environment inside our laboratory, therefore we have tested a smaller version of our prototype system in the very low noise environment at LSBB, Rustrel, France. We have studied the crosstalk between an array of parallel pick-up loops-where the field generated by a current in one loop is detected by the others. We monitored the magnetic field in the LSBB for over twelve hours; and after correcting these data for SQUID resets, and crosstalk, we compare it to the published values from nearby geomagnetic observatories. We have also measured the noise spectrum of our system and studied the effect that heating one of the pick-up loops into its conducting state has on the other, parallel loops.

438

TECHNICAL NOTE: Fabrication of microelectrodes for EDM machining by a combined etching process  

Science.gov (United States)

In this note, multi-headed microelectrodes were machined by a combined sequence process of WEDG, ultrasonic-aided chemical etching and an electrochemical anodic etching procedure. Electrodes were cut to 0.1 mm by a wire EDM machine from an original diameter of 3 mm in the first step. Electrodes were continually machined by chemical etching and anodic electrochemical etching. During electrolysis, copper impurity produced on the anode is not easily removed from its matrix. A ultrasonic mechanism was utilized to agitate the ferric chloride solution to clean the surface impurity off the electrode. The performance of ultrasonic-aided chemical etching was also studied. Micro single electrodes and foil electrodes were processed by chemical etching. Multi-headed microelectrodes can be machined to 30 µm by the combined sequence etching technology proposed.

Weng, Feng-Tsai

2004-05-01

439

SQUID magnetometry for the cryoEDM experiment-Tests at LSBB  

Energy Technology Data Exchange (ETDEWEB)

High precision magnetometry is an essential requirement of the cryoEDM experiment at the Institut Laue-Langevin, Grenoble. We have developed a SQUID system for this purpose, however tests done in Oxford have been limited by the noisy electromagnetic environment inside our laboratory, therefore we have tested a smaller version of our prototype system in the very low noise environment at LSBB, Rustrel, France. We have studied the crosstalk between an array of parallel pick-up loops-where the field generated by a current in one loop is detected by the others. We monitored the magnetic field in the LSBB for over twelve hours; and after correcting these data for SQUID resets, and crosstalk, we compare it to the published values from nearby geomagnetic observatories. We have also measured the noise spectrum of our system and studied the effect that heating one of the pick-up loops into its conducting state has on the other, parallel loops.

Henry, S; Kraus, H; Malek, M; Mikhailik, V B [University of Oxford, Department of Physics, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Waysand, G [Laboratoire Souterrain a Bas Bruit de Rustrel-Pays d' Apt (LSBB), Universite de Nice Sophia-Antipolis, La Grande Combe, 84400 Rustrel (France)], E-mail: s.henry1@physics.ox.ac.uk

2008-11-15

440

Simultaneous Processing Method for Micro-Rods and Holes Using EDM  

Science.gov (United States)

This paper describes a new method for micro-EDM drilling which utilizes the wear of rod electrodes. With this method, a pair of micro rod and micro hole can be machined in a single process, while with conventional methods, the micro rod electrode needs to be formed before machining the micro hole. Processing conditions were optimized for the new method to obtain higher aspect ratio for the micro rods. Results of experiments also showed the following: 1) This method can be applied to AISI1045, AISI304 and Kovar and any electrode diameter size. 2) From the second process, if machining many holes using the same electrode, the electrode shape can be regenerated with excellent repeatability and holes processed efficiently. 3) The influence of carbon adhering to the tip region of the rod electrode is large, which is why the rod electrode becomes needle sharp.

Yamazaki, Minoru; Mori, Noritosi; Suzuki, Takemi; Kunieda, Masanori

First Page Previous Page 1 2 3 4 5 6 7 8 9