7 results on '"R. Bjorkquist"'
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2. Performance of the Muon g−2 calorimeter and readout systems measured with test beam data
- Author
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D.A. Peterson, M. Bartolini, K. L. Giovanetti, N.T. Rider, A. Kuchibhotla, A. Gioiosa, S. Ganguly, A.T. Fienberg, A. Chapelain, H. P. Binney, W. Gohn, R. Bjorkquist, J. Kaspar, C. Schlesier, T. P. Gorringe, M. Iacovacci, A. Driutti, A. Lusiani, S. Leo, M. W. Smith, T. Stuttard, D. W. Hertzog, G. Pauletta, S. Mastroianni, L. K. Gibbons, Dinko Pocanic, G. Venanzoni, Claudio Ferrari, D.A. Sweigart, T. D. Van Wechel, K. S. Khaw, J.B. Hempstead, C. Gabbanini, and A. Fioretti
- Subjects
Physics ,Nuclear and High Energy Physics ,Muon ,Calorimeter (particle physics) ,Physics::Instrumentation and Detectors ,010308 nuclear & particles physics ,business.industry ,Electrical engineering ,7. Clean energy ,01 natural sciences ,Silicon photomultiplier ,Data acquisition ,0103 physical sciences ,Calibration ,Waveform ,Fermilab ,Electronics ,010306 general physics ,business ,Instrumentation - Abstract
A single calorimeter station for the Muon g − 2 experiment at Fermilab includes the following subsystems: a 54-element array of PbF 2 Cherenkov crystals read out by large-area SiPMs, bias and slow-control electronics, a suite of 800 MSPS waveform digitizers, a clock and control distribution network, a gain calibration and monitoring system, and a GPU-based front-end which is read out through a MIDAS data acquisition environment. The entire system performance was evaluated using 2.5–5 GeV electrons at the End Station Test Beam at SLAC. This paper includes a description of the individual subsystems and the results of measurements of the energy response and resolution, energy-scale stability, timing resolution, and spatial uniformity. All measured performances meet or exceed the g − 2 experimental requirements. Based on the success of the tests, the complete production of the required 24 calorimeter stations has been made and installation into the main experiment is complete. Furthermore, the calorimeter response measurements reported here informed the design of the reconstruction algorithms that are now employed in the running g − 2 experiment.
- Published
- 2019
3. The Measurement of the Anomalous Magnetic Moment of the Muon at Fermilab
- Author
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R. Chislett, J. Carroll, D. Cauz, Andrew Smith, M. Lee, A. Anastasi, E. Hazen, M. Eads, G. Pauletta, R. Osofsky, B. Quinn, R. Fatemi, I. Logashenko, S. Baessler, D.A. Sweigart, N. A. Kuchinskiy, M. W. Smith, D. Still, Yannis K. Semertzidis, W. Gohn, K. L. Giovanetti, V. Tishchenko, L. Welty-Rieger, R. Di Stefano, C. Fu, M. Iacovacci, E. Barzi, V. Volnykh, J. F. Ostiguy, D. W. Hertzog, T. Stuttard, V. A. Baranov, C. J. G. Onderwater, Michael Syphers, G. Luo, V. P. Druzhinin, E. Won, P. T. Debevec, C. Yoshikawa, J. Grange, Martin Fertl, Stephen Maxfield, F. Azfar, A. Epps, L Li, P. Winter, C. Johnstone, A. Fioretti, B. Drendel, K. T. Pitts, M R M Warren, L. K. Gibbons, D. Stöckinger, M. Whitley, Donald B. Rubin, M. Rominsky, J. Crnkovic, T. P. Gorringe, T. Walton, C. Ferrari, Z. Meadows, G. Venanzoni, Thomas Teubner, Nicholas A. Pohlman, S. Haciomeroglu, M. Gaisser, M. Wormald, B. Casey, Frederick Gray, H. Freidsam, Marin Karuza, K. R. Lynch, P. Kammel, S. Henry, S.B. Dabagov, A. L. Lyon, C. Schlesier, E. Motuk, Yuri F. Orlov, D. Allspach, N. Rider, T. J. V. Bowcock, B. Abi, N. Kinnaird, D. Babusci, A. Para, R. M. Carey, A. de Gouvea, J. Johnstone, J. P. Miller, S. Lee, A.T. Fienberg, G. Di Sciascio, Y. Kim, H. Schellman, L.P. Alonzi, H Yang, H. Kamal Sayed, B. L. Roberts, Edward J. Swanson, V. N. Duginov, E. Ramberg, E. Frlez, N. S. Froemming, I. Kourbanis, J. Mott, L. Santi, D. Kawall, Giovanni Cantatore, N. V. Khomutov, G. Corradi, D. Flay, C. C. Polly, Nicholas Eggert, S. Marignetti, R. Bjorkquist, S. Kim, Benjamin T. King, D. Moricciani, C. Gabbanini, A. Tewlsey-Booth, V. Krylov, Yu. M. Shatunov, Andre Frankenthal, S. Leo, M. E. Convery, S. Mastroianni, A. Chapelain, A. Palladino, Andrzej Wolski, H. Nguyen, B. Kiburg, Alexander Mikhailichenko, K. W. Merritt, J. Kaspar, Dinko Pocanic, M. Popovic, M. Lancaster, W. M. Morse, Timothy Chupp, M. McEvoy, Dariush Hampai, X. Ji, M. Shenk, S. Al-Kilani, A. K. Soha, D. A. Tarazona, Klaus-Peter Jungmann, Alejandro Garcia, Logashenko, I., Grange, J., Winter, P., Carey, R. M., Hazen, E., Kinnaird, N., Miller, J. P., Mott, J., Roberts, B. L., Crnkovic, J., Morse, W. M., Sayed, H. Kamal, Tishchenko, V., Druzhinin, V. P., Shatunov, Y. M., Bjorkquist, R., Chapelain, A., Eggert, N., Frankenthal, A., Gibbons, L., Kim, S., Mikhailichenko, A., Orlov, Y., Rider, N., Rubin, D., Sweigart, D., Allspach, D., Barzi, E., Casey, B., Convery, M. E., Drendel, B., Freidsam, H., Johnstone, C., Johnstone, J., Kiburg, B., Kourbanis, I., Lyon, A. L., Merritt, K. W., Morgan, J. P., Nguyen, H., Ostiguy, J. F., Para, A., Polly, C. C., Popovic, M., Ramberg, E., Rominsky, M., Soha, A. K., Still, D., Walton, T., Yoshikawa, C., Jungmann, K., Onderwater, C. J. G., Debevec, P., Leo, S., Pitts, K., Schlesier, C., Anastasi, A., Babusci, D., Corradi, G., Hampai, D., Palladino, A., Venanzoni, G., Dabagov, S., Ferrari, C., Fioretti, A., Gabbanini, C., Di Stefano, R., Marignetti, S., Iacovacci, M., Mastroianni, S., Di Sciascio, G., Moricciani, D., Cantatore, Giovanni, Karuza, M., Giovanetti, K., Baranov, V., Duginov, V., Khomutov, N., Krylov, V., Kuchinskiy, N., Volnykh, V., Gaisser, M., Haciomeroglu, S., Kim, Y., Lee, S., Lee, M., Semertzidis, Y. K., Won, E., Fatemi, R., Gohn, W., Gorringe, T., Bowcock, T., Carroll, J., King, B., Maxfield, S., Smith, A., Teubner, T., Whitley, M., Wormald, M., Wolski, A., Al Kilani, S., Chislett, R., Lancaster, M., Motuk, E., Stuttard, T., Warren, M., Flay, D., Kawall, D., Meadows, Z., Syphers, M., Tarazona, D., Chupp, T., Tewlsey Booth, A., Quinn, B., Eads, M., Epps, A., Luo, G., Mcevoy, M., Pohlman, N., Shenk, M., de Gouvea, A., Welty Rieger, L., Schellman, H., Abi, B., Azfar, F., Henry, S., Gray, F., Fu, C., Ji, X., Li, L., Yang, H., Stockinger, D., Cauz, D., Pauletta, G., Santi, L., Baessler, S., Frlez, E., Pocanic, D., Alonzi, L. P., Fertl, M., Fienberg, A., Froemming, N., Garcia, A., Hertzog, D. W., Kammel, P., Kaspar, J., Osofsky, R., Smith, M., Swanson, E., Lynch, K., Precision Frontier, Ostiguy, J. -F., Cantatore, G., Al-Kilani, S., Tewlsey-Booth, A., Welty-Rieger, L., and Abys, Salvatore
- Subjects
Particle physics ,magnetic moment ,standard model ,General Physics and Astronomy ,Standard deviation ,Standard Model ,Muon magnetic moment ,Nuclear physics ,Physics and Astronomy (all) ,anomalous magnetic moment ,Positron ,muon anomaly ,muon ,Fermilab ,Physical and Theoretical Chemistry ,instrumentation ,Physics ,Muon ,Anomalous magnetic moment ,Standard model ,Chemistry (all) ,Anomalous magnetic dipole moment ,Magnetic moment ,General Chemistry ,Magnetic field ,High Energy Physics::Experiment ,measurement ,muon, magnetic moment, instrumentation, measurement - Abstract
The anomalous magnetic moment of the muon is one of the most precisely measured quantities in experimental particle physics. Its latest measurement at Brookhaven National Laboratory deviates from the Standard Model expectation by approximately 3.5 standard deviations. The goal of the new experiment, E989, now under construction at Fermilab, is a fourfold improvement in precision. Here, we discuss the details of the future measurement and its current status. C 2015 AIP Publishing LLC. [http://dx.doi.org/10.1063/1.4917553]
- Published
- 2015
4. The New Muon g-2 experiment at Fermilab
- Author
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B. Abi T. Albahri, S. Al-Kilani, D. Allspach, L. P. Alonzi, A. Anastasi, F. Azfar, D. Babusci, S. Baessler, V. A. Baranov, E. Barzi, R. Bjorkquist, T. Bowcock, G. Cantatore, R. M. Carey, J. Carroll, B. Casey, D. Cauz, A. Chapelain, S. Chappa, S. Chattopadhyay, R. Chislett, T. E. Chupp, M. Convery, G. Corradi, J. Crnkovic, S. Dabagov, P. T. Debevec, G. Di Sciascio, R. Di Stefano, B. Drendel, V. P. Druzhinin, V. N. Duginov, M. Eads, N. Eggert, A. Epps, R. Fatemi, C. Ferrari, M. Fertl, A. T. Fienberg, A. Fioretti, D. Flay, A. S. Frankenthal, H. Friedsam, E. Frlez, N. S. Froemming, C. Fu, C. Gabbanini, M. Gaisser, S. Ganguly, A. Garcia, J. George, L. K. Gibbons, K. L. Giovanetti, S. Goadhouse, W. Gohn, T. Gorringe, J. Grange, F. Gray, S. Haciomeroglu, T. Halewood-Leagas, D. Hampai, E. Hazen, S. Henry, D. W. Hertzog, J. L. Holzbauer, M. Iacovacci, C. Johnstone, J. A. Johnstone, K. Jungmann, H. Kamal Sayed, P. Kammel, M. Karuza, J. Kaspar, D. Kawall, L. Kelton, K. S. Khaw, N. V. Khomutov, B. Kiburg, S. C. Kim, Y. I. Kim, B. King, N. Kinnaird, I. A. Koop, I. Kourbanis, V. A. Krylov, A. Kuchibhotla, N. A. Kuchinskiy, M. Lancaster, M. J. Lee, S. Lee, S. Leo, L. Li, I. Logashenko, G. Luo, K. R. Lynch, A. Lyon, S. Marignetti, S. Mastroianni, S. Maxfield, M. McEvoy, Z. Meadows, W. Merritt, A. A. Mikhailichenko, J. P. Miller, J. P. Morgan, D. Moricciani, W. M. Morse, J. Mott, E. Motuk, H. Nguyen, Y. Orlov, R. Osofsky, J. -F. Ostiguy, A. Palladino, G. Pauletta, K. Pitts, D. Pocanic, N. Pohlman, C. Polly, J. Price, B. Quinn, N. Raha, E. Ramberg, N. T. Rider, J. L. Ritchie, B. L. Roberts, M. Rominsky, D. L. Rubin, L. Santi, C. Schlesier, Y. K. Semertzidis, Y. M. Shatunov, M. Shenk, A. Smith, M. W. Smith, A. Soha, E. Solodov, D. Still, D. Stöckinger, T. Stuttard, H. E. Swanson, D. A. Sweigart, M. J. Syphers, S. Szustkowski, D. Tarazona, T. Teubner, A. E. Tewlsey-Booth, V. Tishchenko, G. Venanzoni, V. P. Volnykh, T. Walton, M. Warren, L. Welty-Rieger, M. Whitley, P. Winter, A. Wolski, E. Won, M. Wormald, W. Wu, H. Yang, C. Yoshikawa, Albahri, B. Abi T., Al-Kilani, S., Allspach, D., Alonzi, L. P., Anastasi, A., Azfar, F., Babusci, D., Baessler, S., Baranov, V. A., Barzi, E., Bjorkquist, R., Bowcock, T., Cantatore, G., Carey, R. M., Carroll, J., Casey, B., Cauz, D., Chapelain, A., Chappa, S., Chattopadhyay, S., Chislett, R., Chupp, T. E., Convery, M., Corradi, G., Crnkovic, J., Dabagov, S., Debevec, P. T., Di Sciascio, G., Di Stefano, R., Drendel, B., Druzhinin, V. P., Duginov, V. N., Eads, M., Eggert, N., Epps, A., Fatemi, R., Ferrari, C., Fertl, M., Fienberg, A. T., Fioretti, A., Flay, D., Frankenthal, A. S., Friedsam, H., Frlez, E., Froemming, N. S., Fu, C., Gabbanini, C., Gaisser, M., Ganguly, S., Garcia, A., George, J., Gibbons, L. K., Giovanetti, K. L., Goadhouse, S., Gohn, W., Gorringe, T., Grange, J., Gray, F., Haciomeroglu, S., Halewood-Leagas, T., Hampai, D., Hazen, E., Henry, S., Hertzog, D. W., Holzbauer, J. L., Iacovacci, M., Johnstone, C., Johnstone, J. A., Jungmann, K., Kamal Sayed, H., Kammel, P., Karuza, M., Kaspar, J., Kawall, D., Kelton, L., Khaw, K. S., Khomutov, N. V., Kiburg, B., Kim, S. C., Kim, Y. I., King, B., Kinnaird, N., Koop, I. A., Kourbanis, I., Krylov, V. A., Kuchibhotla, A., Kuchinskiy, N. A., Lancaster, M., Lee, M. J., Lee, S., Leo, S., Li, L., Logashenko, I., Luo, G., Lynch, K. R., Lyon, A., Marignetti, S., Mastroianni, S., Maxfield, S., Mcevoy, M., Meadows, Z., Merritt, W., Mikhailichenko, A. A., Miller, J. P., Morgan, J. P., Moricciani, D., Morse, W. M., Mott, J., Motuk, E., Nguyen, H., Orlov, Y., Osofsky, R., Ostiguy, J. -F., Palladino, A., Pauletta, G., Pitts, K., Pocanic, D., Pohlman, N., Polly, C., Price, J., Quinn, B., Raha, N., Ramberg, E., Rider, N. T., Ritchie, J. L., Roberts, B. L., Rominsky, M., Rubin, D. L., Santi, L., Schlesier, C., Semertzidis, Y. K., Shatunov, Y. M., Shenk, M., Smith, A., Smith, M. W., Soha, A., Solodov, E., Still, D., Stöckinger, D., Stuttard, T., Swanson, H. E., Sweigart, D. A., Syphers, M. J., Szustkowski, S., Tarazona, D., Teubner, T., Tewlsey-Booth, A. E., Tishchenko, V., Venanzoni, G., Volnykh, V. P., Walton, T., Warren, M., Welty-Rieger, L., Whitley, M., Winter, P., Wolski, A., Won, E., Wormald, M., Wu, W., Yang, H., and Yoshikawa, C.
- Subjects
Precision Physics, Muon magnetic anomaly, Muon g-2 experiment - Abstract
There is a long standing discrepancy between the Standard Model prediction for the muon and the value measured by the Brookhaven E821 Experiment. At present the discrepancy stands at about three standard deviations, with a comparable accuracy between experiment and theory. Two new proposals – at Fermilab and J-PARC – plan to improve the experimental uncertainty by a factor of 4, and it is expected that there will be a significant reduction in the uncertainty of the Standard Model prediction. I will review the status of the planned experiment at Fermilab, E989, which will analyse 21 times more muons than the BNL experiment and discuss how the systematic uncertainty will be reduced by a factor of 3 such that a precision of 0.14 ppm can be achieved.
- Published
- 2015
5. Studies of an array of PbF2 Cherenkov crystals with large-area SiPM readout
- Author
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Claudio Ferrari, Dinko Pocanic, D. W. Hertzog, D.A. Peterson, K. Yai, T. D. Van Wechel, Andre Frankenthal, P. Kammel, V. Tishchenko, C. Gabbanini, W. Gohn, M. Iacovacci, S.D. Goadhouse, M. W. Smith, K. L. Giovanetti, L.P. Alonzi, B. Kiburg, R. Bjorkquist, G. Venanzoni, D. Cauz, K.B. Wall, A. Fioretti, P. Winter, A. Anastasi, A.T. Fienberg, L. Gibbons, Liang Li, J. Kaspar, S. Mastroianni, G. Pauletta, D.A. Sweigart, R. Fatemi, T. P. Gorringe, Fienberg, A. T., Alonzi, L. P., Anastasi, A., Bjorkquist, R., Cauz, D., Fatemi, R., Ferrari, C., Fioretti, A., Fankenthal, A., Gabbanini, C., Gibbons, L. K., Giovanetti, K., Goadhouse, S. D., Gohn, W. P., Gorringe, T. P., Hertzog, D. W., Iacovacci, M., Kammel, P., Kaspar, J., Kiburg, B., Li, L., Mastroianni, S., Pauletta, G., Peterson, D. A., Počanić, D., Smith, M. W., Sweigart, D. A., Tishchenko, V., Venanzoni, G., Van Wechel, T. D., Wall, K. B., Winter, P., and Yai, K.
- Subjects
Nuclear and High Energy Physics ,Physics - Instrumentation and Detectors ,Physics::Instrumentation and Detectors ,FOS: Physical sciences ,Silicon photomultiplier ,01 natural sciences ,Signal ,law.invention ,High Energy Physics - Experiment ,Nuclear physics ,High Energy Physics - Experiment (hep-ex) ,Optics ,Electromagnetic calorimeter ,law ,0103 physical sciences ,Calibration ,Waveform ,Fermilab ,010306 general physics ,Instrumentation ,Cherenkov radiation ,Nuclear and High Energy Physic ,Physics ,Lead-fluoride crystals ,010308 nuclear & particles physics ,business.industry ,Instrumentation and Detectors (physics.ins-det) ,Laser ,Lead-fluoride crystal ,3. Good health ,High Energy Physics::Experiment ,business ,Energy (signal processing) - Abstract
The electromagnetic calorimeter for the new muon (g-2) experiment at Fermilab will consist of arrays of PbF2 Cherenkov crystals read out by large-area silicon photo-multiplier (SiPM) sensors. We report here on measurements and simulations using 2.0 -- 4.5 GeV electrons with a 28-element prototype array. All data were obtained using fast waveform digitizers to accurately capture signal pulse shapes versus energy, impact position, angle, and crystal wrapping. The SiPMs were gain matched using a laser-based calibration system, which also provided a stabilization procedure that allowed gain correction to a level of 1e-4 per hour. After accounting for longitudinal fluctuation losses, those crystals wrapped in a white, diffusive wrapping exhibited an energy resolution sigma/E of (3.4 +- 0.1) % per sqrt(E/GeV), while those wrapped in a black, absorptive wrapping had (4.6 +- 0.3) % per sqrt(E/GeV). The white-wrapped crystals---having nearly twice the total light collection---display a generally wider and impact-position-dependent pulse shape owing to the dynamics of the light propagation, in comparison to the black-wrapped crystals, which have a narrower pulse shape that is insensitive to impact position., Comment: 14 pages, 19 figures, accepted to Nucl.Instrum.Meth. A. In v2, edited Figures 14,15, and 17 for clarity, improved explanation of energy resolution systematics, added reference to SiPM
- Published
- 2015
6. Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm.
- Author
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Abi B, Albahri T, Al-Kilani S, Allspach D, Alonzi LP, Anastasi A, Anisenkov A, Azfar F, Badgley K, Baeßler S, Bailey I, Baranov VA, Barlas-Yucel E, Barrett T, Barzi E, Basti A, Bedeschi F, Behnke A, Berz M, Bhattacharya M, Binney HP, Bjorkquist R, Bloom P, Bono J, Bottalico E, Bowcock T, Boyden D, Cantatore G, Carey RM, Carroll J, Casey BCK, Cauz D, Ceravolo S, Chakraborty R, Chang SP, Chapelain A, Chappa S, Charity S, Chislett R, Choi J, Chu Z, Chupp TE, Convery ME, Conway A, Corradi G, Corrodi S, Cotrozzi L, Crnkovic JD, Dabagov S, De Lurgio PM, Debevec PT, Di Falco S, Di Meo P, Di Sciascio G, Di Stefano R, Drendel B, Driutti A, Duginov VN, Eads M, Eggert N, Epps A, Esquivel J, Farooq M, Fatemi R, Ferrari C, Fertl M, Fiedler A, Fienberg AT, Fioretti A, Flay D, Foster SB, Friedsam H, Frlež E, Froemming NS, Fry J, Fu C, Gabbanini C, Galati MD, Ganguly S, Garcia A, Gastler DE, George J, Gibbons LK, Gioiosa A, Giovanetti KL, Girotti P, Gohn W, Gorringe T, Grange J, Grant S, Gray F, Haciomeroglu S, Hahn D, Halewood-Leagas T, Hampai D, Han F, Hazen E, Hempstead J, Henry S, Herrod AT, Hertzog DW, Hesketh G, Hibbert A, Hodge Z, Holzbauer JL, Hong KW, Hong R, Iacovacci M, Incagli M, Johnstone C, Johnstone JA, Kammel P, Kargiantoulakis M, Karuza M, Kaspar J, Kawall D, Kelton L, Keshavarzi A, Kessler D, Khaw KS, Khechadoorian Z, Khomutov NV, Kiburg B, Kiburg M, Kim O, Kim SC, Kim YI, King B, Kinnaird N, Korostelev M, Kourbanis I, Kraegeloh E, Krylov VA, Kuchibhotla A, Kuchinskiy NA, Labe KR, LaBounty J, Lancaster M, Lee MJ, Lee S, Leo S, Li B, Li D, Li L, Logashenko I, Lorente Campos A, Lucà A, Lukicov G, Luo G, Lusiani A, Lyon AL, MacCoy B, Madrak R, Makino K, Marignetti F, Mastroianni S, Maxfield S, McEvoy M, Merritt W, Mikhailichenko AA, Miller JP, Miozzi S, Morgan JP, Morse WM, Mott J, Motuk E, Nath A, Newton D, Nguyen H, Oberling M, Osofsky R, Ostiguy JF, Park S, Pauletta G, Piacentino GM, Pilato RN, Pitts KT, Plaster B, Počanić D, Pohlman N, Polly CC, Popovic M, Price J, Quinn B, Raha N, Ramachandran S, Ramberg E, Rider NT, Ritchie JL, Roberts BL, Rubin DL, Santi L, Sathyan D, Schellman H, Schlesier C, Schreckenberger A, Semertzidis YK, Shatunov YM, Shemyakin D, Shenk M, Sim D, Smith MW, Smith A, Soha AK, Sorbara M, Stöckinger D, Stapleton J, Still D, Stoughton C, Stratakis D, Strohman C, Stuttard T, Swanson HE, Sweetmore G, Sweigart DA, Syphers MJ, Tarazona DA, Teubner T, Tewsley-Booth AE, Thomson K, Tishchenko V, Tran NH, Turner W, Valetov E, Vasilkova D, Venanzoni G, Volnykh VP, Walton T, Warren M, Weisskopf A, Welty-Rieger L, Whitley M, Winter P, Wolski A, Wormald M, Wu W, and Yoshikawa C
- Abstract
We present the first results of the Fermilab National Accelerator Laboratory (FNAL) Muon g-2 Experiment for the positive muon magnetic anomaly a_{μ}≡(g_{μ}-2)/2. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency ω_{a} between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring. The storage ring magnetic field is measured using nuclear magnetic resonance probes calibrated in terms of the equivalent proton spin precession frequency ω[over ˜]_{p}^{'} in a spherical water sample at 34.7 °C. The ratio ω_{a}/ω[over ˜]_{p}^{'}, together with known fundamental constants, determines a_{μ}(FNAL)=116 592 040(54)×10^{-11} (0.46 ppm). The result is 3.3 standard deviations greater than the standard model prediction and is in excellent agreement with the previous Brookhaven National Laboratory (BNL) E821 measurement. After combination with previous measurements of both μ^{+} and μ^{-}, the new experimental average of a_{μ}(Exp)=116 592 061(41)×10^{-11} (0.35 ppm) increases the tension between experiment and theory to 4.2 standard deviations.
- Published
- 2021
- Full Text
- View/download PDF
7. Microscopic picture of aging in SiO2.
- Author
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Vollmayr-Lee K, Bjorkquist R, and Chambers LM
- Subjects
- Microscopy methods, Temperature, Models, Chemical, Molecular Dynamics Simulation, Silicon Dioxide chemistry
- Abstract
We investigate the aging dynamics of amorphous SiO(2) via molecular dynamics simulations of a quench from a high temperature T(i) to a lower temperature T(f). We obtain a microscopic picture of aging dynamics by analyzing single particle trajectories, identifying jump events when a particle escapes the cage formed by its neighbors, and determining how these jumps depend on the waiting time t(w), the time elapsed since the temperature quench to T(f). We find that the only t(w)-dependent microscopic quantity is the number of jumping particles per unit time, which decreases with age. Similar to previous studies for fragile glass formers, we show here for the strong glass former SiO(2) that neither the distribution of jump lengths nor the distribution of times spent in the cage are t(w) dependent. We conclude that the microscopic aging dynamics is surprisingly similar for fragile and strong glass formers.
- Published
- 2013
- Full Text
- View/download PDF
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