J. DiSciacca

Harvard University, Cambridge, Massachusetts, United States

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Publications (7)35.71 Total impact

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    ABSTRACT: Previous measurements with a single trapped proton or antiproton detected spin resonance from the increased scatter of frequency measurements caused by many spin flips. Here a measured correlation confirms that individual spin transitions and states are detected instead. The high fidelity suggests that it may be possible to use quantum jump spectroscopy to measure the p and \pbar magnetic moments much more precisely.
    Physical Review Letters 03/2013; 110(14). DOI:10.1103/PhysRevLett.110.140406 · 7.73 Impact Factor
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    ABSTRACT: \DeclareRobustCommand{\pbar}{\HepAntiParticle{p}{}{}\xspace} \DeclareRobustCommand{\p}{\HepParticle{p}{}{}\xspace} \DeclareRobustCommand{\mup}{$\mu_{p}${}{}\xspace} \DeclareRobustCommand{\mupbar}{$\mu_{\pbar}${}{}\xspace} \DeclareRobustCommand{\muN}{$\mu_N${}{}\xspace For the first time a single trapped \pbar is used to measure the \pbar magnetic moment ${\bm\mu}_{\pbar}$. The moment ${\bm\mu}_{\pbar} = \mu_{\pbar} {\bm S}/(\hbar/2)$ is given in terms of its spin ${\bm S}$ and the nuclear magneton (\muN) by $\mu_{\pbar}/\mu_N = -2.792\,845 \pm 0.000\,012$. The 4.4 parts per million (ppm) uncertainty is 680 times smaller than previously realized. Comparing to the proton moment measured using the same method and trap electrodes gives $\mu_{\pbar}/\mu_p = -1.000\,000 \pm 0.000\,005$ to 5 ppm, for a proton moment ${\bm{\mu}}_{p} = \mu_{p} {\bm S}/(\hbar/2)$, consistent with the prediction of the CPT theorem.
    Physical Review Letters 01/2013; 110(13). DOI:10.1103/PhysRevLett.110.130801 · 7.73 Impact Factor
  • Acta Physica Polonica B, Proceedings Supplement 01/2013; 6(4):1093. DOI:10.5506/APhysPolBSupp.6.1093
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    J DiSciacca, G Gabrielse
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    ABSTRACT: The proton magnetic moment in nuclear magnetons is measured to be $\mu_p/\mu_N \equiv g/2 = 2.792\,846 \pm 0.000\,007$, a 2.5 ppm (parts per million) uncertainty. The direct determination, using a single proton in a Penning trap, demonstrates the first method that should work as well with an antiproton as with a proton. This opens the way to measuring the antiproton magnetic moment (whose uncertainty has essentially not been reduced for 20 years) at least $10^3$ times more precisely.
    Physical Review Letters 04/2012; 108(15):153001. DOI:10.1103/PhysRevLett.108.153001 · 7.73 Impact Factor
  • J. D. Wright, J. M. DiSciacca, J. M. Lambert
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    ABSTRACT: Using scaled-energy Stark spectroscopy, we report the observation of recurrences due to closed orbits, both geometric and diffractive, in the ν=0, R=1, nd Rydberg series of H2 (16<n<26) interacting with the ν=0, R=3 series (13<n<15). The data support the molecular closed-orbit theory prediction of diffractive trajectories due to inelastic scattering of the excited electron on the molecular core. We have made similar measurements in He, and a comparison between the recurrence properties of H2 and its united atom equivalent is given.
    Physical Review A 06/2010; 81(6). DOI:10.1103/PhysRevA.81.063409 · 2.99 Impact Factor
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    N Guise, J DiSciacca, G Gabrielse
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    ABSTRACT: The first one-proton self-excited oscillator (SEO) and one-proton feedback cooling are demonstrated. In a Penning trap with a large magnetic gradient, the SEO frequency is resolved to the high precision needed to detect a one-proton spin flip. This is after undamped magnetron motion is sideband-cooled to a 14 mK theoretical limit, and despite random frequency shifts (larger than those from a spin flip) that take place every time sideband cooling is applied in the gradient. The observations open a possible path towards a million-fold improved comparison of the antiproton and proton magnetic moments.
    Physical Review Letters 04/2010; 104(14):143001. DOI:10.1103/PHYSREVLETT.104.143001 · 7.73 Impact Factor
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    ABSTRACT: We report the observation of an electric quadrupole transition between the 4s{sup '}[1/2]â{sup o} and 3d[3/2]â{sup o} states in the spectrum of argon and use it in the first step of a scheme to excite Rydberg states. The initial identification of the transition is based on one-color, two-photon photoionization. A different experiment utilizing two-color, two-photon photoexcitation to Rydberg states confirms the identification. Despite the unavoidable background of one-color, two-photon photoionization, the latter experimental technique makes possible two-photon spectroscopy of Rydberg states using a resonant intermediate state populated by an electric quadrupole transition.
    Journal of the Optical Society of America B 03/2008; 25(3):334-337. DOI:10.1364/JOSAB.25.000334 · 1.81 Impact Factor