What happens when two synchronized clocks on a rigid beam are both given the exact same acceleration profile? Will they remain synchronized? What if we use a rigid-rod Rindler acceleration profile? ...The special relativity prediction surprises many people. This experimental setup is the special-relativity analog of the gravitational redshift. Just like two clocks higher and lower in a gravitational field lose synchronization, one sees a loss of synchronization in these clocks with `identical' acceleration profiles. To the best of our knowledge this equivalence principle analog has never been directly measured, and current experimental techniques are sensitive enough to measure it. We discuss the origin of the essential physics behind this synchronization loss, and some special conditions which simplify its experimental observation. We discuss the origin of the essential physics behind this synchronization loss, and some special conditions which simplify its experimental observation. If validated this effect will not only test the equivalence principle from a new vantage, but it may one day aid in understanding and enhancing future ultra-precise navigation systems.
This letter reports on a search for {nu}{sub {mu}} {yields} {nu}{sub e} transitions by the MINOS experiment based on a 3.14 x 10{sup 20} protons-on-target exposure in the Fermilab NuMI beam. We ...observe 35 events in the Far Detector with a background of 27 {+-} 5(stat.) {+-} 2(syst.) events predicted by the measurements in the Near Detector. If interpreted in terms of {nu}{sub {mu}} {yields} {nu}{sub e} oscillations, this 1.5 {sigma} excess of events is consistent with sin{sup 2}(2{theta}{sub 13}) comparable to the CHOOZ limit when |{Delta}m{sup 2}| = 2.43 x 10{sup -3} eV{sup 2} and sin{sup 2} (2{theta}{sub 23}) = 1.0 are assumed.
We measure the cross section for e+e- -->psi(3770) -->hadrons at Ec.m.=3773 MeV to be (6.38+/-0.08(+0.41)(-0.30) nb using the CLEO detector at the CESR e+e- collider. The difference between this and ...the e+e- -->psi(3770) -->DD cross section at the same energy is found to be (-0.01+/-0.08(+0.41)(-0.30) nb. With the observed total cross section, we extract Gamma(ee)(psi(3770))=(0.204+/-0.003(+0.041)(-0.027) keV. Uncertainties shown are statistical and systematic, respectively.
We measure the cross section for e{sup +}e{sup -}{yields}{psi}(3770){yields}hadrons at E{sub c.m.}=3773 MeV to be (6.38{+-}0.08{sub -0.30}{sup +0.41}) nb using the CLEO detector at the CESR e{sup ...+}e{sup -} collider. The difference between this and the e{sup +}e{sup -}{yields}{psi}(3770){yields}DD cross section at the same energy is found to be (-0.01{+-}0.08{sub -0.30}{sup +0.41}) nb. With the observed total cross section, we extract {gamma}{sub ee}({psi}(3770))=(0.204{+-}0.003{sub -0.027}{sup +0.041}) keV. Uncertainties shown are statistical and systematic, respectively.
Using 420 pb(-1) of data collected on the upsilon(5S) resonance with the CLEO III detector, we reconstruct B mesons in 25 exclusive decay channels to measure or set upper limits on the decay rate of ...upsilon(5S) into B meson final states. We measure the inclusive B cross section to be sigma(upsilon(5S) --> BB(X)) = (0.177 +/- 0.030 +/- 0.016) nb and make the first measurements of the production rates of sigma(upsilon(5S) --> B*B*) = (0.131 +/- 0.025 +/- 0.014) nb and sigma(upsilon(5S) --> BB*) = (0.043 +/- 0.016 +/- 0.006) nb, respectively. We set 90% confidence level limits of sigma(upsilon(5S) -->BB) < 0.038 nb, sigma(upsilon(5S) --> B(*)B(*)pi) < 0.055 nb and sigma(upsilon(5S) --> BBpipi) < 0.024 nb. We also extract the most precise value of the B(s)* mass to date, M(B(s)*) = (5411.7 +/- 1.6 +/- 0.6) MeV/c2.
This letter reports results from the MINOS experiment based on its initial exposure to neutrinos from the Fermilab NuMI beam. The rates and energy spectra of charged current {nu}{sub {mu}} ...interactions are compared in two detectors located along the beam axis at distances of 1 km and 735 km. With 1.27 x 10{sup 20} 120GeV protons incident on the NuMI target, 215 events with energies below 30GeV are observed at the Far Detector, compared to an expectation of 336 {+-} 14.4 events. The data are consistent with {nu}{sub {mu}} disappearance via oscillations with |{Delta}m{sub 32}{sup 2}| = 2.74{sub -0.26}{sup +0.44} x 10{sup -3} eV{sup 2}/c{sup 4} and sin{sup 2} (2{theta}{sub 23}) > 0.87 (68% C.L.).
We present the first experimental limits on high-q2 contributions to charmless semileptonic decays of the form expected from the weak annihilation (WA) decay mechanism. Such contributions could bias ...determinations of /Vub/ from inclusive measurements of B-->Xulupsilon. Using a wide range of models based on available theoretical input we set a limit of GammaWA/Gammab-->u<7.4% (90% confidence level) on the WA fraction, and assess the impact on previous inclusive determinations of /Vub/.
We determine the dielectron widths of the Gamma(1S), Gamma(2S), and Gamma(3S) resonances with better than 2% precision by integrating the cross section of e+e- -->Gamma over the e+e- center-of-mass ...energy. Using e+e- energy scans of the Gamma resonances at the Cornell Electron Storage Ring and measuring Gamma production with the CLEO detector, we find dielectron widths of 1.252+/-0.004(sigma(stat))+/-0.019(sigma(syst)) keV, 0.581+/-0.004+/-0.009 keV, and 0.413+/-0.004+/-0.006 keV for the Gamma(1S), Gamma(2S), and Gamma(3S), respectively.
The 5.4 kton MINOS far detector has been taking charge-separated cosmic ray muon data since the beginning of August, 2003 at a depth of 2070 m.w.e. in the Soudan Underground Laboratory, Minnesota, ...USA. The data with both forward and reversed magnetic field running configurations were combined to minimize systematic errors in the determination of the underground muon charge ratio. When averaged, two independent analyses find the charge ratio underground to be N{sub {mu}}+/N{sub {mu}}-=1.374{+-}0.004(stat)-0.010{sup +0.012}(sys). Using the map of the Soudan rock overburden, the muon momenta as measured underground were projected to the corresponding values at the surface in the energy range 1-7 TeV. Within this range of energies at the surface, the MINOS data are consistent with the charge ratio being energy independent at the 2 standard deviation level. When the MINOS results are compared with measurements at lower energies, a clear rise in the charge ratio in the energy range 0.3-1.0 TeV is apparent. A qualitative model shows that the rise is consistent with an increasing contribution of kaon decays to the muon charge ratio.
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