Light dark matter annihilation and scattering in LHC detectors

We systematically study models with light scalar and pseudoscalar dark matter candidates and their potential signals at the LHC. First, we derive cosmological bounds on models with the Standard Model Higgs mediator and with a new weak-scale mediator. Next, we study two processes inspired by the indirect and direct detection process topologies, now happening inside the LHC detectors. We find that LHC can observe very light dark matter over a huge mass range if it is produced in mediator decays and then scatters with the detector material to generate jets in the nuclear recoil.

Dynamics of nuclear recoil: QM-MD simulations ofmodel systems following β-decay

The kinetic recoil energy received by the daughter nucleus in a nuclear decay is often large enough to affect the structure around the nucleus in chemical systems. The coinciding element change...

Sensitivity of direct detection experiments to neutrino magnetic dipole moments

With large active volume sizes dark matter direct detection experiments are sensitive to solar neutrino fluxes. Nuclear recoil signals are induced by 8B neutrinos, while electron recoils are mainly generated by the pp flux. Measurements of both processes offer an opportunity to test neutrino properties at low thresholds with fairly low backgrounds. In this paper we study the sensitivity of these experiments to neutrino magnetic dipole moments assuming 1, 10 and 40 tonne active volumes (representative of XENON1T, XENONnT and DARWIN), 0.3 keV and 1 keV thresholds. We show that with nuclear recoil measurements alone a 40 tonne detector could be as competitive as Borexino, TEXONO and GEMMA, with sensitivities of order 8.0 × 10−11μB at the 90% CL after one year of data taking. Electron recoil measurements will increase sensitivities way below these values allowing to test regions not excluded by astrophysical arguments. Using electron recoil data and depending on performance, the same detector will be able to explore values down to 4.0 × 10−12μB at the 90% CL in one year of data taking. By assuming a 200-tonne liquid xenon detector operating during 10 years, we conclude that sensitivities in this type of detectors will be of order 10−12μB. Reducing statistical uncertainties may enable improving sensitivities below these values.

Релятивистский расчёт эффекта отдачи ядра для g-фактора состояния ^2P-=SUB=-3/2-=/SUB=- многозарядных бороподобных ионов

The nuclear recoil effect on the $^2 P_{3/2}$-state $g$ factor of B-like ions is calculated to first order in the electron-to-nucleus mass ratio $m/M$ in the range $Z=18$--$92$. The calculations are performed by means of the $1/Z$ perturbation theory. Within the independent-electron approximation, the one- and two-electron recoil contributions are evaluated to all orders in the parameter $\alpha Z$ by employing a fully relativistic approach. The interelectronic-interaction correction of first order in $1/Z$ is treated within the Breit approximation. Higher orders in $1/Z$ are partially taken into account by incorporating the screening potential into the zeroth-order Hamiltonian. The most accurate to date theoretical predictions for the nuclear recoil contribution to the bound-electron $g$ factor are obtained.

Direct dark matter research by observing electrons produced in neutralino-nucleus collisions

The most important process for directly detecting dark matter is the LSP-nucleus elastic scattering by measuring the energy of the recoiling nucleus. In the present work we explore a novel process that is the detection of the dark matter constituents by observing the low energy ionization electrons. We develop the formalism and apply it in calculating the ratio of the ionization rate to the nuclear recoil rate in a variety of atoms. The obtained ratios are essentially independent of all parameters of supersymmetry except the neutralino mass, but they crucially depend on the electron energy cut off. Based on our results it is both interesting and realistic to detect the LSP by measuring the ionization electrons following the-LSP nuclear collisions.