Anisotropy induced Feshbach resonances in a quantum dipolar gas of magnetic atoms

We explore the anisotropic nature of Feshbach resonances in the collision between ultracold magnetic submerged-shell dysprosium atoms, which can only occur due to couplings to rotating bound states. This is in contrast to well-studied alkali-metal atom collisions, where most Feshbach resonances are hyperfine induced and due to rotation-less bound states. Our novel first-principle coupled-channel calculation of the collisions between open-4f-shell spin-polarized bosonic dysprosium reveals a striking correlation between the anisotropy due to magnetic dipole-dipole and electrostatic interactions and the Feshbach spectrum as a function of an external magnetic field. Over a 20 mT magnetic field range we predict about a dozen Feshbach resonances and show that the resonance locations are exquisitely sensitive to the dysprosium isotope.Comment: 5 pages, 4 figure

Molecular ion trap-depletion spectroscopy of BaCl+^+

We demonstrate a simple technique for molecular ion spectroscopy. BaCl$^+$ molecular ions are trapped in a linear Paul trap in the presence of a room-temperature He buffer gas and photodissociated by driving an electronic transition from the ground X$^1\Sigma^+$ state to the repulsive wall of the A$^1\Pi$ state. The photodissociation spectrum is recorded by monitoring the induced trap loss of BaCl$^+$ ions as a function of excitation wavelength. Accurate molecular potentials and spectroscopic constants are determined. Comparison of the theoretical photodissociation cross-sections with the measurement shows excellent agreement. This study represents the first spectroscopic data for BaCl$^+$ and an important step towards the production of ultracold ground-state molecular ions.Comment: 5 pages, 5 figure

New Physics and CP Violation in Singly Cabibbo Suppressed D Decays

We analyze various theoretical aspects of CP violation in singly Cabibbo suppressed (SCS) D-meson decays, such as $D \to K K,\pi \pi$. In particular, we explore the possibility that CP asymmetries will be measured close to the present level of experimental sensitivity of $O(10^{-2})$. Such measurements would signal new physics. We make the following points: (i) The mechanism at work in neutral D decays could be indirect or direct CP violation (or both). (ii) One can experimentally distinguish between these possibilities. (iii) If the dominant CP violation is indirect, then there are clear predictions for other modes. (iv) Tree-level direct CP violation in various known models is constrained to be much smaller than $10^{-2}$. (v) SCS decays, unlike Cabibbo favored or doubly Cabibbo suppressed decays, are sensitive to new contributions from QCD penguin operators and especially from chromomagnetic dipole operators. This point is illustrated with supersymmetric gluino-squark loops, which can yield direct CP violating effects of $O(10^{-2})$.Comment: 36 pages, 5 figure

Prototyping bespoke sensor industrial internet-of-things (IIoT) systems for small and medium enterprises (SMEs)

This paper aims to share our experiences gained from working on multiple industrial–academic collaborative projects within the Digital Innovation for Growth (DIfG) regional programme. This initiative provided academic expertise to low-resource SMEs. The projects primarily revolved around measuring various process or structural health variables. The subsequent wireless reporting of these results to an online dashboard and generating alert messages when variables exceeded predefined thresholds were central to our work. Due to the diverse nature of our partners’ requirements, there was no one-size-fits-all solution for the considered use cases. We will delve into our utilization and insights regarding various IoT-related tools and technologies. These include ESP32 WiFi-enabled microcontrollers, WiFi Manager, NTP time service, watchdog timers, Adafruit IO dashboards and the Twilio SMS gateway, as well as LoRa modules and networks such as TNT and Helium. By effectively combining these tools and technologies, we successfully completed prototypes that enabled testing of the devices on-site

Black holes as antimatter factories

We consider accretion of matter onto a low mass black hole surrounded by ionized medium. We show that, because of higher mobility of protons than electrons, the black hole would acquire positive electric charge. If the black hole's mass is about or below $10^{20}$ g, the electric field at the horizon can reach the critical value which leads to vacuum instability and electron--positron pair production by the Schwinger mechanism. Since the positrons are ejected by the emergent electric field, while electrons are back--captured, the black hole operates as an antimatter factory which effectively converts protons into positrons.Comment: 5 pages, no figure. v2: with discussion section not included in the refereed versio

Laser-ion acceleration through controlled surface contamination

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98750/1/PhysPlasmas_18_040702.pd

The Study of Dielectric Properties of Biological Tissue under Thermal Modification in vitro

The aim of this paper is to study the dynamics of the dielectric properties of the tissue in the experimental controlled thermal modification. Material and methods: the experiment was performed on equal in volume and mass samples of intraoperatively removed tissue of Palmar aponeurosis (n=8). The thermal effect was simulated by placing tissue fragments in a thermostat (processing time – 5 min., temperature – 60 C). Duration of exposure after thermal modification was 5 min. Dielectric properties of tissues was determined using an original hardware-software complex for near-field resonant microwave sensing. Results: the study made it possible to verify the shifts in dielectric properties of the tissue that occur under short-term exposure to high temperature in vitro. It is shown that the dielectric permeability and conductivity of the biological object are significantly reduced under the influence of this factor, which is primarily due to a decrease of its hydration degree

Multiple filamentation of laser beams with different diameters in the air at a 100-meter path

Results of experiments on controlling the position and length of the filamentation zone of femtosecond laser pulses in atmospheric path length 110 m using different initial spatial focusing and defocusing. The obtained distribution of filaments along the filamentation zone, measured dependence the length of the filamentation zone of the numerical aperture of the beam, its initial radius and pulse power

Global self-focusing and features of multiple filamentation of radiation of a subterawatt Ti:sapphire laser with a centimeter output aperture along a 150-m path

The formation and propagation of postfilamentation channels along a controllable path 150 m long are studied experimentally for collimated beams of different diameters. During multiple filamentation, a laser beam is compressed into a global focus, after passing which its angular divergence is much greater than the divergence of postfilamentation channels generated during the filamentation. It is shown that the intensity of the postfilamentation channels is sufficient for starting multiple filamentation in optical elements at distances much longer than the filamentation region length