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 muons, as well as the combined result, d(mu) = (0.0 +/- 0.9) x 10(-19)e cm, are all consistent with zero, we set a new muon EDM limit, vertical bar d(mu)vertical bar < 1.8 x 10(-19)e cm (95% C.L.). This represents a factor of 5 improvement over the previous best limit on the muon EDM.

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.

In the muon (g-2) experiment at Brookhaven National Laboratory, the spin precession frequency ωa is obtained from a standard χ2 minimization fit applied to the time distribution of decay electrons. The unusually high accuracy (∼0.5ppm) of the experiment puts stringent requirements on the quality of the fit and the level of understanding of the statistical properties of the fitted parameters. We discuss the properties of the fits and their implications on the derived value for ωa, including estimates of the effect of an imperfect fit function, methods of including additional external information to reduce the error, the effects of splitting the data into many smaller subsets of data, applying different weighting methods to the data using energy information, and various tests of data suitability.

We present the final report from a series of precision measurements of the muon anomalous magnetic moment, a(mu)=(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 a(mu)(Expt)=11659208.0(5.4)(3.3)x10(-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 a(mu) includes contributions from virtual QED, weak, and hadronic processes. While the QED processes account for most of the anomaly, the largest theoretical uncertainty, approximate to 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.

The muon (g-2) experiment is described, and the recent results are presented. These results represent the final measurement for the positive muon.

The muon (g-2) experiment at Brookhaven National Laboratory has measured the anomalous magnetic moment of the positive muon with a precision of 0.7 ppm. This paper presents that result, concentrating on some of the important experimental issues that arise in extracting the anomalous precession frequency from the data.

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 unions were successfully accomplished in 1997-2000 and 2001, respectively. Results of the 1997-2000 runs have been published, thus completing our experiment for mu(+). Data analysis for the 2001 run for mu(-) is currently in progress. To provide measurement of a(mu)- = 1/2(g-2)(mu)- at the same level of accuracy as for a(mu)+ = 1/2(g-2)(mu)+, we need to have one more data taking run.

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.

Received 22 August 2002DOI:https://doi.org/10.1103/PhysRevLett.89.129903©2002 American Physical Society

The status of the muon g — 2 experiment at the AGS facility of Brookhaven National Laboratory is discussed. Data obtained in 1999 with positive muons has been analyzed and published. The final data set contained 0.95 × 109 events and had an accuracy of 1.3ppm. Approximately four times more data with positive muons and three times more data with negative muons were obtained in 2000 and 2001, respectively. These data were obtained with a more uniform magnetic field and with different storage ring tunes. An accuracy of the order of 0.5ppm is anticipated.

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 µ – = ½(g – 2) µ – at the same level of accuracy as for a µ + = ½(g – 2) µ +, we would need one more data-taking run. PACS Nos.: 31.15Pf, 31.30Jv, 32.10Hq

The muon g-2 experiment at Brookhaven National Laboratory (BNL) has the goal of determining the muon anomalous magnetic moment, aμ(=(g-2)/2), to the very high precision of 0.35 parts per million and thus requires a storage ring magnet with great stability and homogeneity. A super-ferric storage ring has been constructed in which the field is to be known to 0.1ppm. In addition, a new type of air core superconducting inflector has been developed and constructed, which successfully serves as the injection magnet. The injection magnet cancels the storage ring field, 1.5T, seen by the entering muon beam very close to the storage ring aperture. At the same time, it gives negligible influence to the knowledge of the uniform main magnetic field in the muon storage region located at just 23mm away from the beam channel. This was accomplished using a new double cosine theta design for the magnetic field which traps most of the return field, and then surrounding the magnet with a special superconducting sheet which traps the remaining return field. The magnet is operated using a warm-to-cold cryogenic cycle which avoids affecting the precision field of the storage ring. This article describes the design, research development, fabrication process, and final performance of this new type of superconducting magnet.

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).

A precision measurement of the anomalous g value, aµ=(g-2)/2, for the positive muon has been made using high intensity protons available at the Brookhaven AGS. The result based on the 1999 data aµ=11659202(14)(6)x 10 10 (1.3ppm) 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)= 11659159.6(6.7) x 10 10 (0.57 ppm) and differ by over 2.5 standard deviation with experiment. Issues with reducing systematic errors and enhancing the injection and storage efficiencies are discussed.

The new muon (g−2) experiment at BNL aims at a final precision of 0.35 ppm on the muon anomaly. The experiment has completed four runs beginning in 1997 and has sub-ppm data on tape. Analyzed data include a published 13 ppm result from our initial commissioning run and a recently completed 5 ppm result from our 1998 initial muon injection run. We are actively working on the remainder of the data analysis and on systematic studies.

The vibrational spectra of four genomic and two synthetic DNAs, encompassing a wide range in base composition [poly(dA-dT). poly(dA-dT), 0% G + C; Clostridium perfringens DNA, 27% G + C; calf thymus DNA, 42% G + C; Escherichia coli DNA, 50% G + C; Micrococcus luteus DNA, 72% G + C; poly(dG-dC).poly(dG-dC), 100% G + C] (dA: deoxyadenosine; dG: deoxyguanosine; dC: deoxycytidine; dT: thymidine), have been analyzed using Raman difference methods of high sensitivity. The results show that the Raman signature of B DNA depends in detail upon both genomic base composition and sequence. Raman bands assigned to vibrational modes of the deoxyribose-phosphate backbone are among the most sensitive to base sequence, indicating that within the B family of conformations major differences occur in the backbone geometry of AT- and GC-rich domains. Raman bands assigned to in-plane vibrations of the purine and pyrimidine bases-particularly of A and T-exhibit large deviations from the patterns expected for random base distributions, establishing that Raman hypochromic effects in genomic DNA are also highly sequence dependent. The present study provides a basis for future use of Raman spectroscopy to analyze sequence-specific DNA-ligand interactions. The demonstration of sequence dependency in the Raman spectrum of genomic B DNA also implies the capability to distinguish genomic DNAs by means of their characteristic Raman signatures.

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.

Light scattering and electron microscopy have been used to investigate the structural effects of the trivalent complexes hexaammine cobalt (III) chloride (Cohex), tris(ethylenediamine) cobalt(III) chloride (Coen), and cobalt(III) sepulchrate chloride (Cosep) on DNA condensation. These cobalt-amine compounds have similar ligand coordination geometries but differ slightly in size. Their hydrophobicity is in the order Cosep > Coen > Cohex, according to the numbers of methylene groups in these ligands. All of these compounds effectively precipitate DNA at high concentrations; but despite a lower surface charge density, Cosep condenses DNA twice as effectively as Coen or Cohex. UV and CD measurements of the supernatants of cobalt-amine/DNA solutions reveal a preferential binding of Delta-Coen over Lambda-Coen to the precipitated DNA, but there is no chiral selectivity for Cosep. Competition experiments show that the binding strengths of these three cobalt-amine compounds to aggregated DNA are comparable. A charge neutralization of 88-90% is required for DNA condensation. Our data indicate that 1) electrostatic interaction is the main driving force for binding of multivalent cations to DNA; 2) DNA condensation is dependent on the structure of the condensing agent; and 3) the hydration pattern or polarization of water molecules on the surface of condensing agents plays an important role in DNA condensation and chiral recognition.