Search results for "mass [baryon]"
showing 10 items of 262 documents
Physics at CERN's Antiproton Decelerator
2013
The Antiproton Decelerator of CERN began operation in 1999 to serve experiments for studies of CPT invariance by precision laser and microwave spectroscopy of antihydrogen ($\bar{\rm H}$) and antiprotonic helium ($\bar{p}{\rm He}^+$). The first 12 years of operation saw cold $\bar{\rm H}$ synthesized by overlapping clouds of positrons ($e^+$) and antiprotons ($\bar{p}$) confined in magnetic Penning traps. Cold $\bar{\rm H}$ was also produced in collisions between Rydberg positronium atoms and $\bar{p}$. Ground-state $\bar{\rm H}$ was later trapped for up to $\sim 1000$ s in a magnetic bottle trap, and microwave transitions excited between its hyperfine levels. In the $\bar{p}{\rm He}^+$ ato…
Latest predictions from the EbyE NLO EKRT model
2019
We present the latest results from the NLO pQCD + saturation + viscous hydrodynamics (EbyE NLO EKRT) model. The parameters in the EKRT saturation model are fixed by the charged hadron multiplicity in the 0-5 \% 2.76 TeV Pb+Pb collisions. The $\sqrt{s}$, $A$ and centrality dependence of the initial particle production follows then from the QCD dynamics of the model. This allows us to predict the $\sqrt{s}$ and $A$ dependence of the particle production. We show that our results are in an excellent agreement with the low-$p_T$ data from 2.76 TeV and 5.02 TeV Pb+Pb collisions at the LHC as well as with the data from the 200 GeV Au+Au collisions at RHIC. In particular, we study the centrality de…
Determination of mass attenuation coefficient by numerical absorption calibration with Monte-Carlo simulations at 59.54 keV
2016
Abstract This study presents a numerical method in order to determine the mass attenuation coefficient of a sample with an unknown chemical composition at low energy. It is compared with two experimental methods: a graphic method and a transmission method. The method proposes to realise a numerical absorption calibration curve to process experimental results. Demineralised water with known mass attenuation coefficient ( 0.2066 cm 2 g − 1 at 59.54 keV) is chosen to confirm the method. 0.1964 ± 0.0350 cm 2 g − 1 is the average value determined by the numerical method, that is to say less than 5% relative deviation compared to more than 47% for the experimental methods.
Quadrupole interaction of $^{8}$Li and $^{9}$Li in LiNbO$_{3}$ and the quadrupole moment of $^{9}$Li
1988
The quadrupole interaction of nuclear spin polarized8Li (I=2) and9Li (I=3/2) in LiNbO3 has been studied at room temperature. The polarization was achieved by optical pumping of a fast atomic beam with circularly polarized laser light. The atoms were implanted into a hexagonal LiNbO3 single crystal and the quadrupole splitting ofβ-NMR spectra was measured. A ratio of ¦Q(9Li)/Q(8Li)¦=0.88(4) for the nuclear quadrupole moments was deduced, yielding a new value of ¦Q(9Li)¦=25.3 (9) mb for the quadrupole moment of9Li.
Ramsey technique applied in a Penning trap mass spectrometer
1991
Abstract The Ramsey method has been applied in an experiment aiming for accurate mass determination of unstable isotopes. The ion motion in a Penning trap has been excited with time-separated oscillatory fields and Ramsey fringes were observed in the case of dipole and quadrupole excitation. The experimental resonances are in good agreement with theory. Further applications of the technique are discussed.
The squeezer ion guide
1992
Abstract The properties of an ordinary ion guide can be improved by inserting a grid between the nozzle and the skimmer. When positive ions are transported, an electric potential lower than +10 V is connected to the grid and one of the order of − 10 V to the skimmer. Efficient focusing is achieved between the nozzle and the grid by a combined action of the viscous helium flow field and the weak electric field. The focusing device is called a “squeezer”. It can be extended by adding more grids, a second skimmer, and differential pumping. Contrary to the first grid, the additional elements act more or less like electrostatic lenses in medium vacuum. With the squeezer ion guide, ions created i…
Role of dense matter in collective supernova neutrino transformations
2008
6 pages, 2 figures.-- PACS nrs.: 14.60.Pq; 97.60.Bw.-- ArXiv pre-print available at: http://arxiv.org/abs/0807.0659
Combining data from high-energy p p -reactions and neutrinoless double-beta decay: Limits on the mass of the right-handed boson
2016
From the recently established lower-limits on the nonobservability of the neutrinoless double-beta decay of 76Ge (GERDA collaboration) and 136Xe (EXO-200 and KamLAND-Zen collaborations), combined with the ATLAS and CMS data, we extract limits for the left-right (LR) mixing angle, of the SU(2)L ×SU(2)R electroweak Hamiltonian. For the theoretical analysis, which is a model dependent, we have adopted a minimal extension of the Standard Model (SM) of Electroweak Interactions belonging to the SU(2)L ×SU(2)R representation. The nuclear-structure input of the analysis consists of a set of matrix elements and phase-space factors, and the experimental lower-limits for the half-lives. The other inpu…
Systematics of strong nuclear amplification of gluon saturation from exclusive vector meson production in high energy electron–nucleus collisions
2017
We show that gluon saturation gives rise to a strong modification of the scaling in both the nuclear mass number $A$ and the virtuality $Q^2$ of the vector meson production cross-section in exclusive deep-inelastic scattering off nuclei. We present qualitative analytic expressions for how the scaling exponents are modified as well as quantitative predictions that can be tested at an Electron-Ion Collider.
Exact relativistic beta decay endpoint spectrum
2007
5 pages, 3 figures.-- PACS nrs.: 14.60.Pq; 13.30.-a; 23.40.-s; 23.40.Bw.-- ISI Article Identifier: 000250620900070.-- ArXiv pre-print available at: http://arxiv.org/abs/0706.0897