Search results for "Elementary Particle"
showing 10 items of 659 documents
Decay study ofTc114with a Penning trap
2011
The level structure of $^{114}\mathrm{Ru}$ has been investigated via the $\ensuremath{\beta}$ decay of very neutron-rich $^{114}\mathrm{Tc}$ by means of Penning-trap-assisted $\ensuremath{\gamma}$ spectroscopy. The deduced $\ensuremath{\beta}$-decay scheme suggests the existence of two $\ensuremath{\beta}$-decaying states in $^{114}\mathrm{Tc}$ with ${I}^{\ensuremath{\pi}}={1}^{+}$ and $I\ensuremath{\geqslant}$ 4, with half-lives of ${t}_{1/2}({1}^{+})=90(20)$ ms and ${t}_{1/2}(I\ensuremath{\geqslant}4)=100(20)$ ms, respectively. The ${Q}_{\ensuremath{\beta}}$ value, which covers a possible mixture of two states, has been determined to be ${Q}_{\ensuremath{\beta}}=11 785(12)$ keV. The level…
η−η′(−glue) Mixing from the Chiral Lagrangian
2010
The η − η ′ mixing from the chiral Lagrangian is reviewed. It is shown how the Feldman-Kroll-Stech ansazt can be derived from the chiral Lagrangian. The inclusion of the glueball is also discussed.
The Three-Body Problem
1972
The quantum mechanical three-body problem has been studied with increasing interest in the last decade. The main progress was achieved by deriving integral equations which are not only theoretically correct, but also practically applicable. Such equations allow us in particular to investigate, besides three-body bound states, the scattering of an elementary particle from a bound two-particle system.
Penning traps as a versatile tool for precise experiments in fundamental physics
2009
This review article describes the trapping of charged particles. The main principles of electromagnetic confinement of various species from elementary particles to heavy atoms are briefly described. The preparation and manipulation with trapped single particles, as well as methods of frequency measurements, providing unprecedented precision, are discussed. Unique applications of Penning traps in fundamental physics are presented. Ultra-precise trap-measurements of masses and magnetic moments of elementary particles (electrons, positrons, protons and antiprotons) confirm CPT-conservation, and allow accurate determination of the fine-structure constant alpha and other fundamental constants. T…
Dark Matter Results from 100 Live Days of XENON100 Data
2011
We present results from the direct search for dark matter with the XENON100 detector, installed underground at the Laboratori Nazionali del Gran Sasso of INFN, Italy. XENON100 is a two-phase time projection chamber with a 62 kg liquid xenon target. Interaction vertex reconstruction in three dimensions with millimeter precision allows to select only the innermost 48 kg as ultra-low background fiducial target. In 100.9 live days of data, acquired between January and June 2010, no evidence for dark matter is found. Three candidate events were observed in a pre-defined signal region with an expected background of 1.8 +/- 0.6 events. This leads to the most stringent limit on dark matter interact…
Canonical Neutral Current Predictions From The Weak Electromagnetic Gauge Group SU(3) X U(1)
1980
A straightforward SU(3) x U(1) model in which there is effectively one new neutral-current parameter (denoted by R) is shown to give the canonical neutrino neutral-current predictions for all values of R. For small R the ''low-energy'' theory is essentially SU(2) x U(1) while for R of the order of one it has a much richer ''low-energy'' gauge-boson mass spectrum. Even in the latter case, the predicted e-d asymmetry agrees with experiment. It is interesting that the atomic-physics parity violation depends sensitively on R.
Isobar width effects in the coupling of nucleon to isobar channels
1986
The investigation of the effects of isobar coupling to two-nucleon channels has been extended to include additional physical features. A new code discretizes the mass distribution of the isobar widths and treats each mass as a separate channel. This allows the treatment of width in the presence of coupling by transition potentials, in addition to the previously permitted boundary coupling. It also produces the S-italic-matrix components required to describe the many-body final-state distributions. When indicated by the one-pion-exchange coupling strength new isobar channels are included. The new results for nucleon-nucleon scattering fit the data better, starting from more realistic models.…
A precise measurement of the real part of the elastic scattering amplitude at the Sp̄pS
1993
Abstract A precise measurement of pp elastic scattering in the Coulomb-strong interaction interference region was performed at the CERN SppS Collider at a centre-of-mass energy of 541 GeV. The ratio of the real to the imaginary part of the forward elastic scattering amplitude was found to be ρ = 0.135 ± 0.015. The slope of the exponential fall off of the strong interaction part was also measured to be b = 15.5 ± 0.1 GeV −2 .
Octupolar-Excitation Penning-Trap Mass Spectrometry forQ-Value Measurement of Double-Electron Capture inEr164
2011
The theory of octupolar-excitation ion-cyclotron-resonance mass spectrometry is presented which predicts an increase of up to several orders of magnitude in resolving power under certain conditions. The new method has been applied for a direct Penning-trap mass-ratio determination of the $^{164}\mathrm{Er}\mathrm{\text{\ensuremath{-}}}^{164}\mathrm{Dy}$ mass doublet. $^{164}\mathrm{Er}$ is a candidate for the search for neutrinoless double-electron capture. However, the measured ${Q}_{ϵϵ}$ value of 25.07(12) keV results in a half-life of ${10}^{30}$ years for a 1 eV Majorana-neutrino mass.
Probing New Long-Range Interactions by Isotope Shift Spectroscopy
2018
We explore a method to probe new long- and intermediate-range interactions using precision atomic isotope shift spectroscopy. We develop a formalism to interpret linear King plots as bounds on new physics with minimal theory inputs. We focus only on bounding the new physics contributions that can be calculated independently of the standard model nuclear effects. We apply our method to existing Ca[superscript +] data and project its sensitivity to conjectured new bosons with spin-independent couplings to the electron and the neutron using narrow transitions in other atoms and ions, specifically, Sr and Yb. Future measurements are expected to improve the relative precision by 5 orders of magn…