摘要:

The BLAST detector is presently under construction by an international collaboration and it is scheduled to start commissioning in the summer of 2001. The initial scientific program calls for comprehensive measurements of the spin dependent electromagnetic response of the few body systems. A status report of the construction is presented as well as highlights of some of the planned measurements. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1345389

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

The results of searches for various nucleon decay modes using the 61 kton⋅year (991 days) exposure of the Super-Kamiokande water Cherenkov detector will be presented. In particular, nucleon decay into modes favored by supersymmetric (SUSY) grand unified theories (GUTs) will be stressed. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1345390

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

The new approach to the particle oscillations which allows one to work out problems with variable number of particles is considered. It predicts an enhancement of oscillations in the medium. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1345391

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

Measurements ofK0/K¯0time-dependent asymmetries in pionic and semileptonic decays with the CPLEAR detector enabled a complete determination of CPT violation parameters in the neutral kaon system. A global fit using the Bell-Steinberger relation yielded values for the CPT violation parameter inK0mixingIm(&dgr;)=(2.4±5.0)×10−5andRe(&dgr;)=(2.4±2.8)×10−4,the determination of the latter relying essentially on CPLEAR measurements. In addition, CPT violation parameters in semileptonic decaysRe(y)andRe(x−)could be measured for the first time. From these results, the equality ofK0andK0masses and lifetimes is tested at the10−18&hthinsp;GeVlevel. Assuming CPT conservation in decays, the 90&percent; C.L. limit on|mK0−mK¯0|can be pushed down to5×10−19&hthinsp;GeV.CPT violation amplitudes inI=0andI=2decays into two pions were excluded at the level of10−4of the corresponding CPT conserving decay amplitudes. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1345392

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

The E158 experiment at SLAC will make the first measurement of parity violation in Moller scattering. The left-right cross-section asymmetry(ALR)in the elastic scattering of a 45-GeV polarized electron beam with unpolarized electrons in a liquid hydrogen target will be measured. This will give a precise measurement of the weak mixing angle, with&dgr;(sin2&hthinsp;&thgr;Weff)≈0.0008(atQ2=0.03&hthinsp;GeV2). ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1345393

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

The parity violating asymmetry in quasielastic electron scattering from the deuteron at backward scattering angles has been recently measured for the first time. Combined with the previously performed similar measurement on the proton, this measurement provides a determination of both the proton’s strange magnetic form factorGMsand the axial vectore-Nform factorGAs.A preliminary analysis indicates thatGMsis slightly positive but consistent with zero and thatGAe(T=1)is in substantial disagreement with the theoretical estimate. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1345394

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

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. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1345395

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

Muon decay allows for the most precise experiments in testing the Standard Model of electroweak interactions. An experiment aimed to measure one of the Michel parameters with an improvement of 70 is described. A production run is foreseen for summer 2000. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1345396

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

At the Thomas Jefferson National Accelerator Facility, we have studied the elastic scattering of polarized electrons from hydrogen. The resulting parity-violating electroweak asymmetry is sensitive to the contributions of strange quarks to the nucleon form factors at a level that is of theoretical interest. Using events at a laboratory scattering angle of 12.3° and⟨Q2⟩=0.477&hthinsp;GeV/c,we measure the linear combination of strange form factors(GEs+0.39GMs)/(GMp&ggr;/&mgr;p)=0.091±0.054±0.039,where the first error is the quadratic sum of our systematic and statistical errors and the second error is due to uncertainty in nucleon form factors. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1345397

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

Parity violating electron nucleus scattering is a clean and powerful tool for measuring the spatial distributions of neutrons in nuclei with unprecedented accuracy. Parity violation arises from the interference of electromagnetic and weak neutral amplitudes, and theZ0of the Standard Model couples primarily to neutrons at lowQ2.Experiments are now feasible at existing facilities. We show that theoretical corrections are either small or well understood, which makes the interpretation clean. A neutron density measurement may have many implications for nuclear structure, atomic parity nonconservation experiments, and the structure of neutron stars. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1345398

出版商:AIP    

年代:1900

数据来源: AIP