| 1. |
|
|
| 2. |
- Fjelstad, Jens
(author)
-
On 7-D TFT and 6-D chiral CFT
- 2002
-
Other publication (pop. science, debate, etc.)abstract
- We perform a canonical and BRST analysis of a seven-dimensional Chern-Simons theory on a manifold with boundary. The main result is that the 7D theory induces for consistency a chiral two-form on the 6D boundary. We also comment on similar behaviour in a five-dimensional Chern-Simons theory relevant for $\N=4$ supersymmetric Yang-Mills theory in four dimensions.
|
|
| 3. |
- Xu, Zhenxiang, et al.
(author)
-
Novel Monte Carlo representation for shell model in the complex energy plane
-
Other publication (other academic/artistic)abstract
- A Monte Carlo method is presented to evaluate quantum states with many particles moving inthe continuum. The scattering state is generated at each time by a Monte Carlo random samplingalgorithm. The same calculation are repeated until the average energies of all calculations converge.For systems with one and two particles, our calculations show that the exact solution can beapproached with around only one hundred iterations.
|
|
| 4. |
- Binda, Federico, 1987-
(author)
-
Characterization of a NE-213 liquid scintillator for neutron flux measurement at JET
- 2011
-
Other publication (other academic/artistic)abstract
- The measurment of the total neutron rate from a nuclear fusion reactor is very important in order to calculate the power produced in a plasma. An improvement of a method currently in use at JET will involve the installation of an organic liquid scintillator NE-213 of 1 cm3 of volume combined with a digital acquisition card. In this project a first stage of the characterization of the digitizer and of the detector has been performed.
|
|
| 5. |
- Binda, Federico, 1987-
(author)
-
High Count Rate Neutron Detector Installation at JET
- 2011
-
Other publication (other academic/artistic)abstract
- The measurement of fusion power is of paramount importance for the control of a fusion reactor's operation. The neutron yield from the reactor is strictly related to the energy production. One of the methods employed at JET to measure the yield involves the use of the MPRu spectrometer together with the neutron camera. However the MPRu has an intrinsically low efficiency (about 10-6), which results in a poor time resolution. An improvement involving the installation of a NE213 detectorfor high count rate has been proposed. The testing phase of the new instrumentation, conducted at Uppsala University, has shown that the acquisition system works properly and it is ready to be installed on site in view of the coming JET experimental campaign.
|
|
| 6. |
- Holmlid, Leif, 1942
(author)
-
Meson bunches formed by pulsed laser-induced processes in ultra-dense hydrogen H(0)
- 2022
-
Other publication (other academic/artistic)abstract
- Ultra-dense hydrogen H(0) (reviewed in Holmlid and Zeiner-Gundersen, Physica Scripta 2019 ) consists of small strongly bound molecules with interatomic distance of 0.56 pm in spin state s=1. It is a useful nuclear fuel for energy generation, giving heat above break-even (Holmlid, AIP Advances 2015) in laser-induced processes (Holmlid, Int. J. Hydr. Energy 2021). Nuclear processes in H(0) emit particles in typical meson decay chains with kinetic energy up to 100 MeV. These mesons decay and generate fast muons at up to 500 MeV energy at current densities of several mA cm-2 at 1–2 m distances, which corresponds to 1013 -1014 muons formed per laser pulse. It is shown that the mesons decay in chain processes with well-defined meson time constants in the range 10–60 ns. The time varying signals from H(0) agree well with mesons M in decay chains as A ◊ M ◊ N where N is a signal muon. M may be a charged kaon K± (decay time constant at rest 12.4 ns) or a charged pion π± (decay time constant at rest 26 ns) or a long-lived neutral kaon (decay time constant at rest 51 ns). Ultra-dense protium p(0) gives the same time constants as D(0) but slightly different decay-chains. The meson bunches observed are similar to the meson bunches from nucleon+antinucleon annihilation. The energy gain in the nuclear process is at least 8000, strongly indicating baryon annihilation for which process further evidence is given in other recent publications.
|
|
| 7. |
- Niblaeus, Carl, et al.
(author)
-
Effect of polarisation and change of event generator on dark matter annihilation fluxes
-
Other publication (other academic/artistic)abstract
- If indirect detection searches are to be used to discriminate between dark matter particle models, it is crucial to understand the expected energy spectra of secondary particles such as neutrinos, charged antiparticles and gamma rays emerging from dark matter annihilations in the local Universe. We simulate the dark matter annihilation processes and collect the fluxes of the stable end products in the annihilation. In order to get an estimate of the impact of different modelling of the physics in the annihilation process, we compare fluxes obtained with two popular event generators, Pythia8 and Herwig7. We also consider the possible impact of polarisation of the final state in the annihilation, with a specific focuson the impact on neutrino fluxes from dark matter annihilations in the centre of the Sun. We find that differences between the event generators are larger for yields of hadronic end products such as antiprotons, than for leptonic end products. Concerning polarisation, we conversely find the largest differences in the leptonic spectra. We find that for neutrino fluxes from dark matter annihilations in the Sun, differences between the polarisations of the final state are to some extent washed out by neutrino oscillations and interactions in the Sun.
|
|
| 8. |
|
|
| 9. |
- Åkesson, Torsten
(author)
-
Current Status and Future Prospects for the Light Dark Matter eXperiment
-
Other publication (other academic/artistic)abstract
- The constituents of dark matter are still unknown, and the viable possibilities span a vast range of masses. The physics community has established searching for sub-GeV dark matter as a high priority and identified accelerator-based experiments as an essential facet of this search strategy. A key goal of the accelerator-based dark matter program is testing the broad idea of thermally produced sub-GeV dark matter through experiments designed to directly produce dark matter particles. The most sensitive way to search for the production of light dark matter is to use a primary electron beam to produce it in fixed-target collisions. The Light Dark Matter eXperiment (LDMX) is an electron-beam fixed-target missing-momentum experiment that realizes this approach and provides unique sensitivity to light dark matter in the sub-GeV range. This contribution provides an overview of the theoretical motivation, the main experimental challenges, how LDMX addresses these challenges, and projected sensitivities. We further describe the capabilities of LDMX to explore other interesting new and standard physics, such as visibly-decaying axion and vector mediators or rare meson decays, and to provide timely electronuclear scattering measurements that will inform the modeling of neutrino-nucleus scattering for DUNE.
|
|
| 10. |
|
|
