120165522
Mass measurements on stable nuclides in the rare-earth region with the Penning-trap mass spectrometer TRIGA-TRAP
The masses of 15 stable nuclides in the rare-earth region have been measured with the Penning-trap mass spectrometer TRIGA-TRAP. This is the first series of absolute mass measurements linking these nuclides to the atomic-mass standard {sup 12}C. Previously, nuclear reaction studies almost exclusively determined the literature values of these masses in the Atomic-Mass Evaluation. The TRIGA-TRAP results show deviations on the order of 3-4 standard deviations from the latest published values of the Atomic-Mass Evaluation 2003 for some cases. However, the binding-energy differences that are important for nuclear structure studies have been confirmed and improved. The new masses are discussed in the context of valence proton-neutron interactions using double differences of binding energies, {delta}V{sub pn}(Z,N).
96561563
Measurements of ground-state properties for nuclear structure studies by precision mass and laser spectroscopy
Atomic physics techniques like Penning-trap and storage-ring mass spectrometry as well as laser spectroscopy have provided sensitive high-precision tools for detailed studies of nuclear ground-state properties far from the valley of ?-stability. Mass, moment and nuclear charge radius measurements in long isotopic and isotonic chains have allowed extraction of nuclear structure information such as halos, shell and subshell closures, the onset of deformation, and the coexistence of nuclear shapes at nearly degenerate energies. This review covers experimental precision techniques to study nuclear ground-state properties and some of the most recent results for nuclear structure studies.
119242601
Direct mass measurements of cadmium and palladium isotopes and their double-β transition Q values
The Q-value of the double-electron capture in Cd-108 has been determined to be (272.04 +/- 0.55) keV in a direct measurement with the double-Penning trap mass spectrometer TRIGA-TRAP. Based on this result a resonant enhancement of the decay rate of Cd-108 is excluded. We have confirmed the double-beta transition Q-values of Cd-106 and Pd-110 recently measured with the Penning-trap mass spectrometers SHIPTRAP and ISOLTRAP, respectively. Furthermore, the atomic masses of the involved nuclides Cd-106, Cd-108, Cd-110, Pd-106, Pd-108 and Pd-110 have been directly linked to the atomic mass standard.
18098456
A broad-band FT-ICR Penning trap system for KATRIN
The KArlsruhe TRItium Neutrino experiment KATRIN aims at improving the upper limit of the mass of the electron antineutrino to about 0.2 eV (90% c.l.) by investigating theβ-decay of tritium gas molecules T2→ ( 3 HeT) + + e − + ¯ νe. The experiment is currently under construction to start firs t data taking in 2012. One source of systematic uncertainties in the KATRIN experiment is the formation of ion clusters when tritium decays and decay products interact with residual tritium molecules. It is essential to monitor the a bundances of these clusters since they have different final state energies than tritium ions. For this purpose, a protot ype of a cylindrical Penning trap has been constructed and tested at the Max-Planck-Institute for Nuclear Physics in Heidelberg, which will be installed in the KATRIN beam line. This system employs the technique of Fourier-Transform Ion-Cyclotron-Resonance in order to measure the abundances of the different stored ion species.
10468219
High-accuracy Penning trap mass measurements with stored and cooled exotic ions
The technique of Penning trap mass spectrometry is briefly reviewed particularly in view of precision experiments on unstable nuclei, performed at different facilities worldwide. Selected examples of recent results emphasize the importance of high-precision mass measurements in various fields of physics.
119181705
AN HST/WFC3-IR MORPHOLOGICAL SURVEY OF GALAXIES AT z = 1.5-3.6. I. SURVEY DESCRIPTION AND MORPHOLOGICAL PROPERTIES OF STAR-FORMING GALAXIES*
We present the results of a 42-orbit Hubble Space Telescope Wide-Field Camera 3 (HST/WFC3) survey of the rest-frame optical morphologies of star-forming galaxies with spectroscopic redshifts in the range z = 1.5-3.6. The survey consists of 42 orbits of F160W imaging covering ~65 arcmin2 distributed widely across the sky and reaching a depth of 27.9 AB for a 5σ detection within a 0.2 arcsec radius aperture. Focusing on an optically selected sample of 306 star-forming galaxies with stellar masses in the range M_* = 10^9-10^(11) M_☉, we find that typical circularized effective half-light radii range from ~0.7 to 3.0 kpc and describe a stellar mass-radius relation as early as z ~ 3. While these galaxies are best described by an exponential surface brightness profile (Sersic index n ~ 1), their distribution of axis ratios is strongly inconsistent with a population of inclined exponential disks and is better reproduced by triaxial stellar systems with minor/major and intermediate/major axis ratios ~0.3 and 0.7, respectively. While rest-UV and rest-optical morphologies are generally similar for a subset of galaxies with HST/Advanced Camera for Surveys imaging data, differences are more pronounced at higher masses M_* > 3 × 10^(10) M_☉. Finally, we discuss galaxy morphology in the context of efforts to constrain the merger fraction, finding that morphologically identified mergers/non-mergers generally have insignificant differences in terms of physical observables such as stellar mass and star formation rate, although merger-like galaxies selected according to some criteria have statistically smaller effective radii and correspondingly larger Σ_(SFR).
119203296
Degeneracy induced scaling of the correlation length for periodic models
Abstract The broken symmetric phase of scalar models exhibits an infrared fixed point which is induced by the degenerate effective potential. The definition of the correlation length in the infrared regime enables us to determine the type of the phase transition in the model. It is shown that the massive sine-Gordon model exhibits a continuous, while the layered sine-Gordon model has an infinite order Kosterlitz–Thouless type phase transition.
53654202
Super Yang-Mills, division algebras and triality
A bstractWe give a unified division algebraic description of (D = 3, N$$ \mathcal{N} $$ = 1, 2, 4, 8), (D = 4, N$$ \mathcal{N} $$ = 1, 2, 4), (D = 6, N$$ \mathcal{N} $$ = 1, 2) and (D = 10, N$$ \mathcal{N} $$ = 1) super Yang-Mills theories. A given (D = n + 2,N$$ \mathcal{N} $$) theory is completely specified by selecting a pair (An$$ {\mathbb{A}}_n $$, AnN$$ {{\mathbb{A}}_n}_{\mathcal{N}} $$) of division algebras, An$$ {\mathbb{A}}_n $$ ⊆ AnN$$ {{\mathbb{A}}_n}_{\mathcal{N}} $$ = ℝ,ℂ,ℍ,O$$ \mathbb{R},\mathbb{C},\mathrm{\mathbb{H}},\mathbb{O} $$, where the subscripts denote the dimension of the algebras. We present a master Lagrangian, defined over AnN$$ {{\mathbb{A}}_n}_{\mathcal{N}} $$ -valued fields, which encapsulates all cases. Each possibility is obtained from the unique (O,O$$ \mathbb{O},\mathbb{O} $$) (D = 10, N$$ \mathcal{N} $$ = 1) theory by a combination of Cayley-Dickson halving, which amounts to dimensional reduction, and removing points, lines and quadrangles of the Fano plane, which amounts to consistent truncation. The so-called triality algebras associated with the division algebras allow for a novel formula for the overall (spacetime plus internal) symmetries of the on-shell degrees of freedom of the theories. We use imaginary AnN$$ {{\mathbb{A}}_n}_{\mathcal{N}} $$ -valued auxiliary fields to close the non-maximal supersymmetry algebra off-shell. The failure to close for maximally supersymmetric theories is attributed directly to the non-associativity of the octonions.
85464497
Functional renormalization group for quantized anharmonic oscillator
Abstract Functional renormalization group methods formulated in the real-time formalism are applied to the O ( N ) symmetric quantum anharmonic oscillator, considered as a 0 + 1 dimensional quantum field-theoric model, in the next-to-leading order of the gradient expansion of the one- and two-particle irreducible effective action. The infrared scaling laws and the sensitivity-matrix analysis show the existence of only a single, symmetric phase. The Taylor expansion for the local potential converges fast while it is found not to work for the field-dependent wavefunction renormalization, in particular for the double-well bare potential. Results for the gap energy for the bare anharmonic oscillator potential hint on improving scheme-independence in the next-to-leading order of the gradient expansion, although the truncated perturbation expansion in the bare quartic coupling provides strongly scheme-dependent results for the infrared limits of the running couplings.
22530691
Yang-Mills origin of gravitational symmetries.
By regarding gravity as the convolution of left and right Yang-Mills theories together with a spectator scalar field in the biadjoint representation, we derive in linearized approximation, the gravitational symmetries of general covariance, p-form gauge invariance, local Lorentz invariance, and local supersymmetry from the flat space Yang-Mills symmetries of local gauge invariance and global super-Poincaré symmetry. As a concrete example, we focus on the new minimal (12+12) off shell version of simple four-dimensional supergravity obtained by tensoring the off shell Yang-Mills multiplets (4+4, N_{L}=1) and (3+0, N_{R}=0).