Search results for "ground"

Precision Study of η′→γπ+π− Decay Dynamics

2018

Using a low background data sample of 9.7×10^{5}  J/ψ→γη^{'}, η^{'}→γπ^{+}π^{-} events, which are 2 orders of magnitude larger than those from the previous experiments, recorded with the BESIII detector at BEPCII, the decay dynamics of η^{'}→γπ^{+}π^{-} are studied with both model-dependent and model-independent approaches. The contributions of ω and the ρ(770)-ω interference are observed for the first time in the decays η^{'}→γπ^{+}π^{-} in both approaches. Additionally, a contribution from the box anomaly or the ρ(1450) resonance is required in the model-dependent approach, while the process specific part of the decay amplitude is determined in the model-independent approach.

Observation of laser-induced continuum structure in the NO molecule

1999

0953-4075; We present experimental results on the modification of a molecular ionization continuum through a laser-induced continuum structure. The effect is demonstrated in nitric oxide where the resonant 2 + 1 multiphoton-ionization process of the X (2)Pi(3/2) electronic ground state is modified by dressing the continuum with the electromagnetically embedded M(2)Sigma(+) Rydberg state. Through selection of a two-photon rovibronic transition via the D electronic state, a single rotational ground state level is excited to the continuum with one laser field. By adding an extra dressing field, a coupling is then established between this three-photon excited ground state level and one of the M…

Prospects of SPIN Gyroscopes Based on Nitrogen-Vacancy Centers in Diamond

2019

This project aims to develop solid-state gyroscopes based on ensembles of negatively charged nitrogen-vacancy (NV) centers in diamond [1], [2]. The NV center is a defect formed in diamond by one substitutional nitrogen atom and an adjacent vacancy. The NV- center features a ground state with electronic spin $\mathrm{S}=1$ , which can be initialized, manipulated, and detected via convenient optical, microwave and radiofrequency transitions (Fig. 1). Nuclear spins are appealing in the context of gyroscopes because they have much smaller gyromagnetic ratios than that of the electron (by a factor of about 1000), reducing the requirements on static magnetic-field stability and homogeneity. The l…

Coupling of theXΣ+1andaΣ+3states ofKRb

2007

A comprehensive study of the electronic states at the $4s+5s$ asymptote in $\mathrm{KRb}$ is presented. Abundant spectroscopic data on the $a\phantom{\rule{0.2em}{0ex}}^{3}\ensuremath{\Sigma}^{+}$ state were collected by Fourier-transform spectroscopy, which allows one to determine an accurate experimental potential energy curve up to $14.8\phantom{\rule{0.3em}{0ex}}\mathrm{\AA{}}$. The existing data set [C. Amiot et al., J. Chem. Phys. 112, 7068 (2000)] on the ground state $X\phantom{\rule{0.2em}{0ex}}^{1}\ensuremath{\Sigma}^{+}$ was extended by several additional levels lying close to the atomic asymptote. In a coupled channels fitting routine complete molecular potentials for both electr…

AC Stark shift of the ground state of atomic hydrogen

2004

An analytical expression for the second-order AC Stark shift of the ground state of atomic hydrogen is derived, which is convergent for negative as well as for positive energies of intermediate states except for the resonances. To clarify the applicability of the second-order perturbation theory, we compared results with those which are obtained by us and other authors using nonperturbative methods. It appears that values obtained for the AC Stark shift using our simple formula agree on average with Floquet-method calculations up to the field strength F=0.12 (a.u.), which corresponds to I=1015 W/cm2.

New Information on Nuclear Structure in the Cd-In-Sn Region from Laser Spectroscopy and the Question of Core Polarization Contribution to Nuclear Rad…

1986

Nuclear spin, moments and isotope shifts of charge radii have been measured by laser spectroscopy for about 70 nuclear states in the range 48 ≦ Z ≦ 50, 54 ≦ N ≦ 78. 1/2--states in heavy In-isotopes cross the Schmidt line, indicating complex nuclear structure. Magnetic as well as spectroscopic quadrupole moments of most of the odd odd In-isotopes can be reproduced satisfactorily by coupling the respective experimental moments of odd even and even odd neighbouring nuclei. The isotope shift of all three elements exhibits a parabolic shape, which is superimposed to the almost linear droplet model expectation. The shape can be fitted quantitatively to Talmis core polarization model. The curvatur…

Muon capture on light isotopes measured with the Double Chooz detector

2016

Using the Double Chooz detector, designed to measure the neutrino mixing angle $\theta_{13}$, the products of $\mu^-$ capture on $^{12}$C, $^{13}$C, $^{14}$N and $^{16}$O have been measured. Over a period of 489.5 days, $2.3\times10^6$ stopping cosmic $\mu^-$ have been collected, of which $1.8\times10^5$ captured on carbon, nitrogen, or oxygen nuclei in the inner detector scintillator or acrylic vessels. The resulting isotopes were tagged using prompt neutron emission (when applicable), the subsequent beta decays, and, in some cases, $\beta$-delayed neutrons. The most precise measurement of the rate of $^{12}\mathrm C(\mu^-,\nu)^{12}\mathrm B$ to date is reported: $6.57^{+0.11}_{-0.21}\time…

Precision determination of the ground-state hyperfine splitting inBa+137using the ion-storage technique

1982

Intraenvironmental correlations in the ground state of a nonisolated two-state particle

1996

The existence of entanglement in the ground state of a two-level particle coupled to a bosonic environment is proved. The quantum covariances of pairs of simple dynamical variables relative to different subsystems are explicitly shown to be bounded. Physically interpretable conditions for the occurrence of weak intraenvironmental correlations are reported and discussed. The potentialities of our treatment are briefly put into evidence.

Singlet ground state magnetism: III. magnetic excitons in antiferromagnetic TbP

1981

The dispersion of the lowest magnetic excitations of the singlet ground state system TbP has been studied in the antiferromagnetic phase by inelastic neutron scattering. The magnetic exchange interaction and the magnetic and the rhombohedral molecular fields have been determined.