This report describes the physics case, the resulting detector requirements, and the evolving detector concepts for the experimental program at the Electron-Ion Collider (EIC). The EIC will be a powerful new high-luminosity facility in the United States with the capability to collide high-energy electron beams with high-energy proton and ion beams, providing access to those regions in the nucleon and nuclei where their structure is dominated by gluons. Moreover, polarized beams in the EIC will give unprecedented access to the spatial and spin structure of the proton, neutron, and light ions. The studies leading to this document were commissioned and organized by the EIC User Group with the objective of advancing the state and detail of the physics program and developing detector concepts that meet the emerging requirements in preparation for the realization of the EIC. The effort aims to provide the basis for further development of concepts for experimental equipment best suited for the science needs, including the importance of two complementary detectors and interaction regions. This report consists of three volumes. Volume I is an executive summary of our findings and developed concepts. In Volume II we describe studies of a wide range of physics measurements and the emerging requirements on detector acceptance and performance. Volume III discusses general-purpose detector concepts and the underlying technologies to meet the physics requirements. These considerations will form the basis for a world-class experimental program that aims to increase our understanding of the fundamental structure of all visible matter
Very compact objects probe extreme gravitational fields and may be the key to understand outstanding puzzles in fundamental physics. These include the nature of dark matter, the fate of spacetime singularities, or the loss of unitarity in Hawking evaporation. The standard astrophysical description of collapsing objects tells us that massive, dark and compact objects are black holes. Any observation suggesting otherwise would be an indication of beyond-the-standard-model physics. Null results strengthen and quantify the Kerr black hole paradigm. The advent of gravitational-wave astronomy and precise measurements with very long baseline interferometry allow one to finally probe into such foundational issues. We overview the physics of exotic dark compact objects and their observational status, including the observational evidence for black holes with current and future experiments.
Xiaochun Huang, Lingxiao Zhao, Yujia Long, Peipei Wang, Dong Chen, Zhanhai Yang, Hui Liang, Mianqi Xue, Hongming Weng, Zhong Fang, Xi Dai, and Genfu Chen Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China Collaborative Innovation Center of Quantum Matter, Beijing 100084, China (Received 14 May 2015; published 24 August 2015)
Two rich and vibrant fields of investigation—graphene physics and plasmonics—strongly overlap. Not only does graphene possess intrinsic plasmons that are tunable and adjustable, but a combination of graphene with noble-metal nanostructures promises a variety of exciting applications for conventional plasmonics. The versatility of graphene means that graphene-based plasmonics may enable the manufacture of novel optical devices working in different frequency ranges—from terahertz to the visible—with extremely high speed, low driving voltage, low power consumption and compact sizes. Here we review the field emerging at the intersection of graphene physics and plasmonics. Many researchers hope to merge plasmonics and graphene photonics to combine their useful features. The properties and characteristics of plasmons on graphene are reviewed. Prospects for possible future applications are discussed.
Quantum gravity is perhaps the most important open problem in fundamental physics. It is the problem of merging quantum mechanics and general relativity, the two great conceptual revolutions in the physics of the twentieth century. This book discusses the many aspects of the problem, and presents technical and conceptual advances towards a background-independent quantum theory of gravity, obtained in the last two decades. The first part of the book is an exploration on how to re-think basic physics from scratch in the light of the general-relativistic conceptual revolution. The second part is a detailed introduction to loop quantum gravity and the spinfoam formalism. It provides an overview of the current state of the field, including results on area and volume spectra, dynamics, extension of the theory to matter, applications to early cosmology and black-hole physics, and the perspectives for computing scattering amplitudes. The book is completed by a historical appendix which overviews the evolution of the research in quantum gravity, from the 1930s to the present day.
Abstract GENIE [1] is a new neutrino event generator for the experimental neutrino physics community. The goal of the project is to develop a ‘canonical’ neutrino interaction physics Monte Carlo whose validity extends to all nuclear targets and neutrino flavors from MeV to PeV energy scales. Currently, emphasis is on the few-GeV energy range, the challenging boundary between the non-perturbative and perturbative regimes, which is relevant for the current and near future long-baseline precision neutrino experiments using accelerator-made beams. The design of the package addresses many challenges unique to neutrino simulations and supports the full life-cycle of simulation and generator-related analysis tasks. GENIE is a large-scale software system, consisting of ∼ 120 000 lines of C ++ code, featuring a modern object-oriented design and extensively validated physics content. The first official physics release of GENIE was made available in August 2007, and at the time of the writing of this article, the latest available version was v2.4.4.
The spin degree of freedom of an electron or a nucleus is one of the most basic properties of nature and functions as an excellent qubit, as it provides a natural two-level system that is insensitive to electric fields, leading to long quantum coherence times. We review the physics of semiconductor spin qubits, focusing not only on the early achievements of spin initialization, control, and readout in GaAs quantum dots, but also on recent advances in Si and Ge spin qubits, including improved charge control and readout, coupling to other quantum degrees of freedom, and scaling to larger system sizes. We begin by introducing the four major types of spin qubits: single spin qubits, donor spin qubits, singlet-triplet spin qubits, and exchange-only spin qubits. We then review the mesoscopic physics of quantum dots, including single-electron charging, valleys, and spin-orbit coupling. We next give a comprehensive overview of the physics of exchange interactions, a crucial resource for single- and two-qubit control in spin qubits. The bulk of this review is centered on the presentation of results from each major spin qubit type, the present limits of fidelity, and a brief overview of alternative spin qubit platforms. We then give a physical description of the impact of noise on semiconductor spin qubits, aided in large part by an introduction to the filter function formalism. Lastly, we review recent efforts to hybridize spin qubits with superconducting systems, including charge-photon coupling, spin-photon coupling, and long-range cavity-mediated spin-spin interactions. Cavity-based readout approaches are also discussed. This review is intended to give an appreciation for the future prospects of semiconductor spin qubits, while highlighting the key advances in mesoscopic physics over the past two decades that underlie the operation of modern quantum-dot and donor spin qubits.
The ground-state density matrix for a massless free field is traced over the degrees of freedom residing inside an imaginary sphere; the resulting entropy is shown to be proportional to the area (and not the volume) of the sphere. Possible connections with the physics of black holes are discussed.
Muhammad Danish Mujib, Nayab Mubashir, Ahmad Zahid Rao
et al.
<b>Background</b>: The global prevalence of Alzheimer’s disease (AD) has reached 55.2 million. AD is characterized by progressive deterioration in cognition and working memory (WM), which are essential for attention, reasoning, and learning. These impairments are associated with pathological changes in cortical and subcortical regions. Binaural beats (BBs), a non-invasive auditory neuromodulation technique, have demonstrated cognitive enhancement effects in healthy individuals; however, their impact on WM in patients with AD remains largely unexplored. <b>Methods</b>: This study investigated the effects of BB stimulation on WM and cognitive function in the temporal lobe of patients with AD using standardized Low-Resolution Electromagnetic Tomography (sLORETA). Twenty-five patients with AD were randomly assigned to either an experimental group (<i>n</i> = 15) that received BB stimulation or a control group (<i>n</i> = 10) that received standard auditory stimulation. EEG recordings were obtained before and after the intervention. <b>Results</b>: Paired <i>t</i>-tests conducted on timeframe and frequency-wise sLORETA images revealed significant increases (<i>p</i> < 0.05) in theta, alpha1, and alpha2 frequency bands in the experimental group. Activated regions included the inferior, middle, superior, and transverse temporal gyri; Brodmann areas (BA) 20, 21, 22, 40, and 42; as well as networks associated with working memory and cognition. <b>Conclusions</b>: These findings suggest that BB stimulation induces temporal lobe activation, thereby enhancing working memory and cognitive function in patients with AD.
Karine Sartelet, Jules Kerckhoffs, Eleni Athanasopoulou
et al.
Mapping urban pollution is essential for assessing population exposure and addressing associated health impacts. High urban concentrations are due to the proximity of sources such as traffic or residential heating, and to urban density with the presence of buildings that reduce street ventilation. This urban complexity makes fine-scale mapping challenging, even for regulated pollutants such as NO2 and PM2.5. In this study we apply state-of-the-art empirical and deterministic modeling approaches to produce high-resolution (<100 m) pollution maps across five European cities (Paris, Athens, Birmingham, Rotterdam, Bucharest). These methodologies enable full-city mapping capturing intra-urban gradients of concentrations. Depending on the methodology, regulated pollutants (NO2, PM2.5) and/or emerging pollutants (black carbon (BC) and ultrafine particles (UFP characterized here by particulate number concentration PNC)) are considered. For deterministic modelling, different approaches are presented: a multi-scale Eulerian modelling chain down to the street scale with chemistry/aerosol dynamics at all scales, multi-scale hybrid models with Eulerian regional dispersion and Gaussian subgrid dispersion, and a Gaussian-based model. Empirical land use regression models were developed based upon mobile monitoring.To compare the relative performance of the methodologies and to evaluate their performance and limitations, the modelling results are compared to fixed measurement stations. We introduce a standardized metric to quantify spatial and seasonal variability and assess each method’s capacity to reproduce fine-scale urban heterogeneity. We also evaluate how data assimilation affects both concentration accuracy and variability representation—particularly relevant for emerging pollutants where measurement data are sparse. We confirm established seasonal and spatial patterns: spatial variability is more pronounced for PNC, NO2 and BC than PM2.5, and concentrations are higher during the winter periods. We also observe reduced spatial variability in winter for PM2. 5 (linked to residential heating) and for BC in cities with significant wood burning emissions. This study adds unique value by evaluating these patterns using fixed measurement stations, and quantifying them across entire urban areas at very fine spatial resolution (<100 m). Furthermore, important methodological strengths and limitations are pointed out, providing practical guidance for the selection and improvement of urban exposure mapping methods, supporting the implementation of the new EU Air Quality Directive.
Michele Campigotto, Francesca Priotto, Cinzia Francesca Tonello
et al.
<b>Background and Clinical Significance</b>: Orofacial granulomatosis is a rare but often disabling condition potentially associated with inflammatory bowel disease (IBD). Pathogenesis is not well understood, and no disease-specific approved treatment exists to date. <b>Case Presentation</b>: A 26-year-old woman with pan-enteric Crohn’s disease developed buccal swelling and deep oral ulcers histologically confirmed as associated orofacial granulomatosis. Multiple therapies were attempted during her life, including systemic steroids and immunomodulator drugs as Thalidomide, Adalimumab, and Ustekinumab in combination with topical steroid injections and Cyclosporin application, with no or minimal benefit. Only Infliximab showed good efficacy, but it was suspended due to side effects. Following secondary loss of response to Ustekinumab, compassionate treatment with Upadacitinib, a recently developed oral Jak-1 selective inhibitor, resulted in the complete resolution of the oral ulcers. Moreover, after the 12-week induction phase and the transition to 30 mg/daily maintenance dosage, the oral disease remained controlled. Due to the clinical recurrence of Crohn’s disease, Vedolizumab was added as associated treatment, resulting in complete clinical benefit after six months of follow-up. <b>Conclusions</b>: This is a unique case of orofacial granulomatosis associated with pan-enteric Crohn’s disease successfully treated with Upadacitinib. More data are needed to explore its potential benefits in this clinical condition.
Medicine (General), Medical physics. Medical radiology. Nuclear medicine
Abstract Metasomatized mantle xenoliths containing hydrous minerals, such as amphiboles, serpentine, and phlogopite, likely represent the potential mineralogical compositions of the metasomatized upper mantle, where low seismic velocities are commonly observed. This study presents the first experimentally determined single‐crystal elasticity model of an Fe‐free near Ca, Mg‐endmember amphibole tremolite at high pressure and/or temperature conditions (maximum pressure 7.3(1) GPa, maximum temperature 700 K) using Brillouin spectroscopy. We found that sound velocities of amphiboles strongly depend on the Fe content. We then calculated the sound velocities of 441 hydrous‐mineral‐bearing mantle xenoliths collected around the globe, and quantitatively evaluated the roles that amphiboles, phlogopite and serpentine played in producing the low velocity anomalies in the metasomatized upper mantle.