Medium-Assisted Enhancement of X(3872)X(3872) Production from Small to Large Colliding Systems

Studies of exotic hadrons such as the $\chi_{c1} (3872)$ state provide crucial insights into the fundamental force governing the strong interaction dynamics, with an emerging new frontier to investigate their production in high energy collisions where a partonic medium is present. Latest experimental measurements from the Large Hadron Collider show an intriguing evolution pattern of the $\chi_{c1} (3872)$-to-$\psi(2S)$ yield ratio from proton-proton collisions with increasing multiplicities toward proton-lead and lead-lead collisions. Here we propose a novel mechanism of medium-assisted enhancement for the $\chi_{c1} (3872)$ production, which competes with the more conventional absorption-induced suppression and results in a non-monotonic trend from small to large colliding systems. Realistic simulations from this model offer the first quantitative description of all available data. Predictions are made for the centrality dependence of this observable in PbPb collisions as well as for its system size dependence from OO and ArAr to XeXe and PbPb collisions. In both cases, a non-monotonic behavior emerges as the imprint of the competition between enhancement and suppression and can be readily tested by future data.Comment: 7 pages, 4 figure

Linearized integrated microwave photonic circuit for filtering and phase shifting

Photonic integration, advanced functionality, reconfigurability, and high radio frequency (RF) performance are key features in integrated microwave photonic systems that are still difficult to achieve simultaneously. In this work, we demonstrate an integrated microwave photonic circuit that can be reconfigured for two distinct RF functions, namely, a tunable notch filter and a phase shifter. We achieved &gt; 50 dB high-extinction notch filtering over 6-16 GHz and 2π continuously tunable phase shifting over 12-20 GHz frequencies. At the same time, we implemented an on-chip linearization technique to achieve a spurious-free dynamic range of more than 120 dB · Hz 4/5 for both functions. Our work combines multi-functionality and linearization in one photonic integrated circuit and paves the way to reconfigurable RF photonic front-ends with very high performance.</p

Correspondence between Color Glass Condensate and High-Twist Formalism

The Color Glass Condensate (CGC) effective theory and the collinear factorization at high-twist (HT) are two well-known frameworks describing perturbative QCD multiple scatterings in nuclear media. It has long been recognized that these two formalisms have their own domain of validity in different kinematics regions. Taking direct photon production in proton-nucleus collisions as an example, we clarify for the first time the relation between CGC and HT at the level of a physical observable. We show that the CGC formalism beyond shock-wave approximation, and with the Landau-Pomeranchuk-Migdal interference effect is consistent with the HT formalism in the transition region where they overlap. Such a unified picture paves the way for mapping out the phase diagram of parton density in nuclear medium from dilute to dense region.Comment: 7 pages, 3 figures + supplemental materia

High-detectivity ultraviolet photodetectors based on laterally mesoporous GaN

Photodetectors for the ultraviolet (UV) range of the electromagnetic spectrum are in great demand for several technologies, but require the development of novel device structures and materials. Here we report on the high detectivity of UV photodetectors based on well-ordered laterally mesoporous GaN. The specific detectivity of our devices under UV-illumination reaches values of up to 5.3×1014 Jones. We attribute this high specific detectivity to the properties of the mesoporous GaN/metal contact interface: the trapping of photo-generated holes at the interface lowers the Schottky barrier height thus causing a large internal gain. The high detectivity along with the simple fabrication process make these laterally mesoporous GaN photodetectors of great potential for applications that require selective detection of weak optical signals in the UV range

An Improved Current-Doubler Rectifier for the Marine Controlled Source Electromagnetic Transmitter

High power marine controlled source electromagnetic transmitters have gained interest with applications in marine geological survey and mineral resources exploration. The direct current to direct current (DC-DC) converter that is typically used in marine transmitters has some issues, as the insulated-gate bipolar transistor (IGBT) tube cannot achieve zero-voltage switching (ZVS). In particular, lagging-leg switching cannot easily achieve ZVS. The conversion efficiency of the heat converter requires improvement. This paper proposes an improved current-doubler rectifier for the marine controlled source electromagnetic transmitter (ICDR-MCSET). Resonant inductance is increased and a blocking capacitor is added to the converter (DC-DC) circuit, where the converter can achieve ZVS in a wide load range. This results in the effective decrease of the heating temperature and the improvement of transformation efficiency. Saber software simulation and a 20 KW electromagnetic transmitter are used to verify the results, which show that the method is feasible and effective

The Business Model of Digital Platforms for the Sharing Economy: Intensive Case Study Methodology for <uri>Rover.com</uri> Pet Boarding Platform

The sharing economy has allowed idle resources to be used again and is known as a model for the new economy. Advances in network technology have allowed the scale of the sharing economy to be expanded through digital platforms. To our best knowledge, no studies in the literature have explored a pet boarding platform for the sharing economy. This research selected the emerging pet care industry as its scope and took the Rover.com pet boarding digital platform, with the highest market share in the world, as the research object for an intensive case study. Three types of secondary data analysis were used: industry profile analysis, case information, and papers and journals. The business model and value proposition of the platform summarizes the key to the success of digital platforms, which is expected to be helpful to entrepreneurs who want to create a sharing economy marketplace. The research results showed that the sharing economy needs to use digital platforms as a matching intermediary between supply and demand to establish a personal-to-personal transaction pattern and it also needs digital platforms to establish a sense of trust and a guarantee mechanism for participants in the sharing economy. For the digital platform to be profitable, it must identify the platform’s unique value proposition and business model, and set up monitoring of transaction parties and evaluation functions, as well as insurance systems and digital platform IT support