-
G W Bennett,
B Bousquet,
H N Brown,
G Bunce,
R M Carey,
P Cushman,
G.T. Danby,
P T Debevec,
M. Deile,
H Deng, [......],
A Steinmetz, L. R. Sulak,
C Timmermans,
A Trofimov,
D Urner,
P von Walter,
D. Warburton,
D Winn,
A Yamamoto,
D Zimmerman
[show abstract]
[hide abstract]
ABSTRACT: Three independent searches for an electric dipole moment (EDM) of the positive and negative muons have been performed, using spin precession data from the muon g-2 storage ring at Brookhaven National Laboratory. Details on the experimental apparatus and the three analyses are presented. Since the individual results on the positive and negative muon, as well as the combined result, d=-0.1(0.9)E-19 e-cm, are all consistent with zero, we set a new muon EDM limit, |d| < 1.9E-19 e-cm (95% C.L.). This represents a factor of 5 improvement over the previous best limit on the muon EDM. Comment: 19 pages, 15 figures, 7 tables
11/2008;
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G W Bennett,
B Bousquet,
H N Brown,
G Bunce,
R M Carey,
P Cushman,
G T Danby,
P T Debevec,
M Deile,
H Deng, [......],
A Steinmetz, L R Sulak,
C Timmermans,
A Trofimov,
D Urner,
P von Walter,
D Warburton,
D Winn,
A Yamamoto,
D Zimmerman
[show abstract]
[hide abstract]
ABSTRACT: The spin precession frequency of muons stored in the (g-2) storage ring has been analyzed for evidence of Lorentz and CPT violation. Two Lorentz and CPT violation signatures were searched for a nonzero delta omega a(=omega a mu+ - omega a mu-) and a sidereal variation of omega a mu+/-). No significant effect is found, and the following limits on the standard-model extension parameters are obtained: bZ = -(1.0+/-1.1) x 10(-23) GeV; (m mu dZ0 + HXY)=(1.8+/-6.0) x 10(-23) GeV; and the 95% confidence level limits b perpendicular mu+ <1.4 x 10(-24) GeV and b perpendicular mu- <2.6 x 10(-24) GeV.
Physical Review Letters 03/2008; 100(9):091602. · 7.37 Impact Factor
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G. W. Bennett,
B. Bousquet,
H. N. Brown,
G. Bunce,
R. M. Carey,
P. Cushman,
G. T. Danby,
P. T. Debevec,
M. Deile,
H. Deng, [......],
A. Steinmetz, L. R. Sulak,
C. Timmermans,
A. Trofimov,
D. Urner,
P. von Walter,
D. Warburton,
D. Winn,
A. Yamamoto,
D. Zimmerman
[show abstract]
[hide abstract]
ABSTRACT: We present the final report from a series of precision measurements of the muon anomalous magnetic moment, aμ=(g-2)/2. The details of the experimental method, apparatus, data taking, and analysis are summarized. Data obtained at Brookhaven National Laboratory, using nearly equal samples of positive and negative muons, were used to deduce aμ(Expt)=11659208.0(5.4)(3.3)×10-10, where the statistical and systematic uncertainties are given, respectively. The combined uncertainty of 0.54 ppm represents a 14-fold improvement compared to previous measurements at CERN. The standard model value for aμ includes contributions from virtual QED, weak, and hadronic processes. While the QED processes account for most of the anomaly, the largest theoretical uncertainty, ≈0.55 ppm, is associated with first-order hadronic vacuum polarization. Present standard model evaluations, based on e+e- hadronic cross sections, lie 2.2–2.7 standard deviations below the experimental result.
Phys. Rev. D. 04/2006; 73(7).
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G W Bennett,
B Bousquet,
H N Brown,
G Bunce,
R M Carey,
P Cushman,
G T Danby,
P T Debevec,
M Deile,
H Deng, [......],
Y K Semertzidis,
P Shagin,
Yu M Shatunov,
E P Sichtermann,
E Solodov,
M Sossong, L R Sulak,
A Trofimov,
P von Walter,
A Yamamoto
[show abstract]
[hide abstract]
ABSTRACT: The anomalous magnetic moment of the negative muon has been measured to a precision of 0.7 ppm (ppm) at the Brookhaven Alternating Gradient Synchrotron. This result is based on data collected in 2001, and is over an order of magnitude more precise than the previous measurement for the negative muon. The result a(mu(-))=11 659 214(8)(3) x 10(-10) (0.7 ppm), where the first uncertainty is statistical and the second is systematic, is consistent with previous measurements of the anomaly for the positive and the negative muon. The average of the measurements of the muon anomaly is a(mu)(exp)=11 659 208(6) x 10(-10) (0.5 ppm).
Physical Review Letters 05/2004; 92(16):161802. · 7.37 Impact Factor
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S. I. Redin,
G. W. Bennett,
B. Bousquet,
H. N. Brown,
G. Bunce,
R. M. Carey,
P. Cushman,
G. T. Danby,
P. T. Debevec,
M. Deile, [......],
A. Steinmetz, L. R. Sulak,
C. Timmermans,
A. Trofimov,
D. Urner,
P. von Walter,
D. Warburton,
D. Winn,
A. Yamamoto,
D. Zimmerman
[show abstract]
[hide abstract]
ABSTRACT: The measurement of the (g−2) value of leptons provides a unique test of theory since it is the only quantity (unlike charge
and mass) calculable in the framework of the Standard Model of elementary particles. The muon (g−2) experiment E821 is currently
in progress at Brookhaven National Laboratory. Four data taking runs for positive muons and one run for negative muons were
successfully accomplished in 1997–2000 and 2001, respectively. Results of the 1997–2000 runs have been published, thus completing
our experiment for μ+. Data analysis for the 2001 run for μ
− is currently in progress. To provide measurement of $a_\mu = \tfrac{1}
{2}(g - 2)_{\mu ^ - }$a_\mu = \tfrac{1}
{2}(g - 2)_{\mu ^ - } at the same level of accuracy as for $a_{\mu ^ + } = \tfrac{1}
{2}(g - 2)_{\mu ^ + }$a_{\mu ^ + } = \tfrac{1}
{2}(g - 2)_{\mu ^ + }, we need to have one more data taking run.
12/2003: pages 163-174;
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G W Bennett,
B Bousquet,
H N Brown,
G Bunce,
R M Carey,
P Cushman,
G T Danby,
P T Debevec,
M Deile,
H Deng, [......],
E P Sichtermann,
E Solodov,
M Sossong,
A Steinmetz, L R Sulak,
A Trofimov,
D Urner,
P Von Walter,
D Warburton,
A Yamamoto
[show abstract]
[hide abstract]
ABSTRACT: A higher precision measurement of the anomalous g value, a(mu)=(g-2)/2, for the positive muon has been made at the Brookhaven Alternating Gradient Synchrotron, based on data collected in the year 2000. The result a(mu(+))=11 659 204(7)(5)x10(-10) (0.7 ppm) is in good agreement with previous measurements and has an error about one-half that of the combined previous data. The present world average experimental value is a(mu)(expt)=11 659 203(8)x10(-10) (0.7 ppm).
Physical Review Letters 10/2002; 89(10):101804. · 7.37 Impact Factor
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H N Brown,
G Bunce,
R M Carey,
P Cushman,
G T Danby,
P T Debevec,
M Deile,
H Deng,
W Deninger,
S K Dhawan, [......],
A Steinmetz, L R Sulak,
C Timmermans,
A Trofimov,
D Urner,
P von Walter,
D Warburton,
D Winn,
A Yamamoto,
D Zimmerman
[show abstract]
[hide abstract]
ABSTRACT: A precise measurement of the anomalous g value, a(mu) = (g-2)/2, for the positive muon has been made at the Brookhaven Alternating Gradient Synchrotron. The result a(mu+) = 11 659 202(14) (6) x 10(-10) (1.3 ppm) is in good agreement with previous measurements and has an error one third that of the combined previous data. The current theoretical value from the standard model is a(mu)(SM) = 11 659 159.6(6.7) x 10(-10) (0.57 ppm) and a(mu)(exp) - a(mu)(SM) = 43(16) x 10(-10) in which a(mu)(exp) is the world average experimental value.
Physical Review Letters 04/2001; 86(11):2227-31. · 7.37 Impact Factor
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Vernon W. Hughes,
H. N. Brown,
G. Bunce,
R. M. Carey,
P. Cushman,
G. T. Danby,
P. T. Debevec,
H. Deng,
W. Deninger,
S. K. Dhawan, [......],
A. Steinmetz, L. R. Sulak,
C. Timmermans,
A. Trofimov,
D. Urner,
P. von Walter,
D. Warburton,
D. Winn,
A. Yamamoto,
D. Zimmerman
[show abstract]
[hide abstract]
ABSTRACT: The muon g-2 experiment at the Brookhaven National Laboratory is described, including its motivation, goal and present status. The latest result based on 1998 data is aμ+ = g−2/2 = 11 659 191(59)×10−10 (5 ppm), where the error is primarily statistical. This value agrees with the present theoretical value. Data obtained thus far and now being analyzed should have a statistical error of about 0.5 ppm. © 2001 American Institute of Physics.
AIP Conference Proceedings. 01/2001; 551(1):221-237.
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Y K Semertzidis,
H Brown,
G.T. Danby,
J. W. Jackson,
R. Larsen,
D. M. Lazarus,
W Meng,
W. M. Morse,
C Ozben,
R. Prigl, [......],
G. Sylvestrov,
Y. Orlov,
K. Jungmann,
P T Debevec,
D W Hertzog,
C. J. G. Onderwater,
E.J. Stephenson,
P Cushman,
I Kronkvist,
F J M Farley
[show abstract]
[hide abstract]
ABSTRACT: We are proposing a new method to carry out a dedicated search for a permanent electric dipole moment (EDM) of the muon with a sensitivity at a level of 10^{-24} e cm. The experimental design exploits the strong motional electric field sensed by relativistic particles in a magnetic storage ring. As a key feature, a novel technique has been invented in which the g-2 precession is compensated with radial electric field. This technique will benefit greatly when the intense muon sources advocated by the developers of the muon storage rings and the muon colliders become available. Comment: 16 pages, 3 figures. Submitted for publication in Proceedings of the International Workshop on High Intensity Muon Sources (HIMUS99), KEK, Japan, December 1-4 1999
12/2000;
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R. Prigl,
H.N. Brown,
G. Bunce,
R.M. Carey,
P. Cushman,
G.T. Danby,
P.T. Debevec,
H. Deng,
W. Deninger,
S.K. Dhawan, [......],
A. Steinmetz, L.R. Sulak,
M. Tanaka,
C. Timmermans,
A. Trofimov,
D. Urner,
D. Warburton,
D. Winn,
A. Yamamoto,
D. Zimmerman
[show abstract]
[hide abstract]
ABSTRACT: The muon (g-2) experiment at Brookhaven completed a first run in
June and July 1997. The main components of the experiment, which include
the superconducting inflector, the superferric storage ring, the
electrostatic quadrupoles and the lead-scintillating fiber electron
calorimeters, have been commissioned satisfactorily. Our first
measurement of the ratio R of the spin precession frequency of the
positive muon relative to that of a free proton,
R=(3.707219±0.000048)×10<sup>-3</sup>, is in good agreement
with the previous CERN measurements for μ<sup>+</sup> and μ<sup>-
</sup>, and has approximately the same uncertainty as each of these
measurements. In spring 1998 a muon kicker was installed and
successfully tested in the storage ring magnet and a significant
improvement in the knowledge of the muon g-factor is expected from
upcoming runs in August 1998 and January 1999
IEEE Transactions on Instrumentation and Measurement 05/1999; · 1.21 Impact Factor
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R. Prigl,
H N Brown,
G Bunce,
R M Carey,
P Cushman,
G.T. Danby,
P T Debevec,
H Deng,
W. Deninger,
S K Dhawan, [......],
Yu.M. Shatunov,
E. Solodov, L. R. Sulak,
C Timmermans,
A Trofimov,
D Urner,
D. Warburton,
D Winn,
A Yamamoto,
D Zimmerman
[show abstract]
[hide abstract]
ABSTRACT: The muon (g-2) experiment at Brookhaven has completed a first run. The main components of the experiment, which include the superconducting inflector, the superferric storage ring, the electrostatic quadrupoles and the lead-scintillating fiber electron calorimeters, have been commissioned satisfactorily. The analysis of data taken in June and July 1997 is in progress
Precision Electromagnetic Measurements Digest, 1998 Conference on; 08/1998
-
[show abstract]
[hide abstract]
ABSTRACT: A study of the time evolution of a long-lived ..nu../sub mu/ beam is being performed at Brookhaven National Laboratory (Experiment 704). The proton momentum (1.5 GeV/c/sup 2/) is chosen to concentrate the ..nu../sub mu/ flux at very low energy where all background reactions are kinematically suppressed. Sensitivity to oscillations at large proper times tau varies as l/p (where l is the flight length and p is the momentum of the neutrino) is greatly enhanced by the resulting low neutrino momentum. Transformations ..nu../sub mu/ ..-->.. ..nu../sub e/ are sensed via ..nu../sub e/n ..-->.. e/sup -/p. An early exploratory test using the neutrino detector of the BNL elastic neutrino-proton scattering experiment will be run during 1977. A 200 ton detector for a definitive experiment is also discussed. 14 references.
12/1976
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H. N. Brown,
G. Bunce,
R. M. Carey,
P. Cushman,
G. T. Danby,
P. T. Debevec,
H. Deng,
W. Deninger,
S. K. Dhawan,
V. P. Druzhinin, [......],
A. Steinmetz, L. R. Sulak,
C. Timmermans,
A. Trofimov,
D. Urner,
P. von Walter,
D. Warburton,
D. Winn,
A. Yamamoto,
D. Zimmerman
[show abstract]
[hide abstract]
ABSTRACT: A new measurement of the positive muon’s anomalous magnetic moment has been made at the Brookhaven Alternating Gradient Synchrotron using the direct injection of polarized muons into the superferric storage ring. The angular frequency difference ωa between the angular spin precession frequency ωs and the angular orbital frequency ωc is measured as well as the free proton NMR frequency ωp. These determine R=ωa/ωp=3.707201(19)×10-3. With μμ/μp=3.18334539(10) this gives aμ+=11659191(59)×10-10 (±5 ppm), in good agreement with the previous CERN and BNL measurements for μ+ and μ-, and with the standard model prediction.
Phys. Rev. D. 62(9).
-
V.W. Hughes,
H.N. Brown,
G. Bunce,
R.M. Carey,
P. Cushman,
G.T. Danby,
P.T. Debevec,
M. Deile,
H. Deng,
W. Deninger, [......],
A. Steinmetz, L.R. Sulak,
C. Timmermans,
A. Trofimov,
D. Urner,
P. von Walter,
D. Warburton,
D. Winn,
A. Yamamoto,
D. Zimmerman
[show abstract]
[hide abstract]
ABSTRACT: A precise measurement of the anomalous g value, a+μ = (g − 2)/2, for the positive muon has been made at the Brookhaven Alternating Gradient Synchrotron. The result a+μ = 11 659 202(14)(6) × 10−10 (1.3 ppm) is in good agreement with previous measurements and has an error one third that of the combined previous data. The current theoretical value from the standard model is aμ(SM)= 11 659 159.6(6.7) × 10−10 (0.57 ppm) and aμ(exp)−aμ(SM) = 42(16) × 10−10 in which aμ(exp) is the world average experimental value.
Nuclear Physics B - Proceedings Supplements.
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M.Grosse Perdekamp,
E. Benedict,
D.H. Brown,
R.M. Carey,
W. Earle,
E. Efstathiadis,
M.F. Hare,
E.S. Hazen,
B.J. Hughes,
F. Krienen, [......],
H.E. Ahn,
H. Deng,
S.K. Dhawan,
A. Disco,
F.J.M. Farley,
X. Fei,
V.W. Hughes,
D. Kawall,
J. Pretz,
S.I. Redin
[show abstract]
[hide abstract]
ABSTRACT: The muon g-2 experiment at Brookhaven has successfully completed two exploratory runs using pion injection and direct muon injection for checkout and initial data taking. The main components of the experiment, which include the pion beam line, the superconducting storage ring and inflector magnets, the muon kicker and the lead-scintillating fiber calorimeters have been satisfactorily commissioned. First results on the anomalous magnetic moment of the positive muon from pion injection are good agreement with previos experimental results for aμ+ and aμ− from CERN and of comparable accuracy (13 ppm). Analysis of the 1998 muon injection run is in progress and expected to improve the precision to about 4 ppm. A first production run is scheduled for January 1999 with the goal of reaching the 1 ppm error level.
Nuclear Physics B - Proceedings Supplements.
-
Yannis K. Semertzidis,
G.W. Bennett,
B. Bousquet,
H.N. Brown,
G. Bunce,
R.M. Carey,
P. Cushman,
G.T. Danby,
P.T. Debevec,
M. Deile, [......],
E.P. Sichtermann,
E. Solodov,
M. Sossong,
A. Steinmetz, L.R. Sulak,
A. Trofimov,
D. Urner,
P. von Walter,
D. Warburton,
A. Yamamoto
[show abstract]
[hide abstract]
ABSTRACT: The experimental method together with the analysis method and results of the data taken in 2000 and prospects of the muon anomalous magnetic and electric dipole moment experiments are presented here.
Nuclear Physics B - Proceedings Supplements.
-
G.T. Danby,
L. Addessi,
Z. Armoza,
J. Benante,
H.N. Brown,
G. Bunce,
J.C. Cottingham,
J. Cullen,
J. Geller,
H. Hseuh, [......],
Y. Mizumachi,
A. Yamamoto,
S.K. Dhawan,
A. Disco,
F.J.M. Farley,
X. Fei,
M. Grosse-Perdekamp,
V.W. Hughes,
D. Kawall,
S.I. Redin
[show abstract]
[hide abstract]
ABSTRACT: The muon g-2 experiment at Brookhaven National Laboratory has the goal of determining the muon anomalous g-value to the very high precision of 0.35 parts per million and thus requires a storage ring magnet with great stability and homogeniety. A superferric storage ring with a radius of 7.11 m and a magnetic field of 1.45 T has been constructed in which the field quality is largely determined by the iron, and the excitation is provided by superconducting coils operating at a current of 5200 A. The storage ring has been constructed with maximum attention to azimuthal symmetry and to tight mechanical tolerances and with many features to allow obtaining a homogenous magnetic field. The fabrication of the storage ring, its cryogenics and quench protection systems, and its initial testing and operation are described.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.
