Search

We explore the prospects for probing new physics (NP) beyond the Standard Model (SM) at future lepton colliders through precision measurements of $e^+e^-\to f{\bar f}$ observables off the $Z$ resonance. We consider interference between SM contributions and those arising from dimension-6, four-fermion effective operators that encode the effects of NP, yielding a linear dependence on the latter. This linear dependence in general increases with magnitude of the collision energy offset from the $Z$ pole. We consider a variety of asymmetries in order to enhance the NP-sensitivity while reducing experimental systematic and theoretical, SM uncertainties: an inclusive above and below $Z$-resonance total cross section asymmetry ($A_\sigma$) as well as the conventional forward-backward ($A_{\rm FB}$) and polarization ($A_{\rm pol}$) asymmetries. Based on projected statistical uncertainties at the Circular Electron-Positron Collider (CEPC), we find that t measurement of $A_\sigma$ could extend the sensitivity to the NP mass scale by as much as a factor of $\sim 7$ compared to the present reach obtained with the CERN Large Electron Positron Collider. Inclusion of projected systematic theoretical SM uncertainties substantially reduce this sensitivity gain. For $A_{\rm FB}$, inclusion of experimental systematic uncertainties has a marginal impact on the gain in NP reach, whereas SM theoretical uncertainties remain a significant barrier to realizing the full NP sensitivity. Analogous conclusions apply to the CERN Future Circular Collider (FCC-ee) and International Linear Collider (ILC)., Comment: 27 pages, 8 figures, 5 tables

Horizontal collaboration between operators can save traffic operation costs, a concept that has been particularly validated in the logistics field. Due to the increasing transportation demand and the introduction of charging times for electric vehicles, there is growing pressure on airport ground support services. This study introduces the concept of coalition to airport ground support services. Unlike most studies on horizontal collaboration, the scheduling for airport ground support services needs to particularly consider punctuality issues. In this study, we separately establish electric vehicle scheduling models for operator-separate and operator-cooperated modes and design an algorithm based on the concept of the Adaptive Large Neighborhood Search algorithm, aiming to obtain the electric vehicle scheduling plan with minimum cost and delay time. Furthermore, the study proposes a cost allocation method that considers the degree of sharing among operators to ensure the feasibility of coalition. Finally, we conducted numerical experiments based on actual airport operation data. The experiments verified the effectiveness of the algorithm and the cost allocation method. Compared to solvers, our algorithm can obtain feasible solutions in a shorter time while ensuring that the objective function gap is within 2%. Additionally, the improved cost allocation method is fairer compared to the traditional Shapley method. Numerical experiments also show that coalition can save 15-25% of airport operating costs and 26-39% of delay time, with savings varying based on the sharing parameters. Through quantitative analysis such as sensitivity analysis, the study provides insights into the variation patterns of overall and individual shared utilities and offers suggestions and decision-making mechanisms for the configuration and operation of airport ground operators.

Suppose that $D$ is a digraph, and $H$ is a multi-digraph on $k$ vertices with $q$ arcs. Let $\mathcal{P}(D)$ be the set of paths in a digraph $D$. An $H$-subdivision $(f,g)$ in a digraph $D$ is a pair of bijections $f : V(H)\rightarrow V(D)$ and $g : A(H) \rightarrow \mathcal{P}(D)$ such that for every arc $uv\in A(H)$, $g(uv)$ is a path from $f(u)$ to $f (v)$, and distinct arcs map into internally vertex disjoint paths in $D$. Further, $D$ is arbitrary $H$-linked if any $k$ distinct vertices in $D$ can be extended to an $H$-subdivision $(f,g)$, and the length of each subdivision path can be specified as a number of at least four. In this paper, we prove that there exists a positive integer $n_0 = n_0(k,q)$ such that if $D$ is an oriented graph of order $n\geq n_0$ with minimum semi-degree at least $(3n+3k+6q-3)/8$, then $D$ is arbitrary $H$-linked. This minimum semi-degree is sharp. Also, we refine the bounds on the semi-degree of sufficiently large arbitrary $k$-linked oriented graphs, sufficiently large arbitrary $l$-ordered oriented graphs, and sufficiently large oriented graphs with disjoint cycles of prescribed lengths containing prescribed arcs., Comment: 26 pages,2 figures

Selective acoustic tweezers can focus the acoustic radiation force on a single particle to manipulate it without affecting its neighbors. This has long required highly complex hardware. In this numerical study, we show that pulsed acoustic waves can be used for the selective manipulation of particles using only two pairs of orthogonal transducers. While these tweezers are well-known for their ability to manipulate arrays of particles, we show that selectivity can be achieved by using sequences of acoustic pulses to iteratively construct a combined acoustic potential focused only on the target particle.

We have obtained the constraints on the density dependence of the symmetry energy from neutron-skin thickness data by parity-violating electron scatterings and neutron-star observables using a Bayesian approach, based on the standard Skyrme-Hartree-Fock (SHF) model and its extension as well as the relativistic mean-field (RMF) model. While the neutron-skin thickness data (neutron-star observables) mostly constrain the symmetry energy at subsaturation (suprasaturation) densities, they may more or less constrain the behavior of the symmetry energy at suprasaturation (subsaturation) densities, depending on the energy-density functional form. Besides showing the final posterior density dependence of the symmetry energy, we also compare the slope parameters of the symmetry energy at 0.10 fm$^{-3}$ as well as the values of the symmetry energy at twice saturation density from three effective nuclear interactions. The present work serves as a comparison study based on relativistic and non-relativistic energy-density functionals, for constraining the nuclear symmetry energy from low to high densities using a Bayesian approach., Comment: 10 pages, 7 figures

The Circular Electron Positron Collider (CEPC) has been proposed to enable more thorough and precise measurements of the properties of Higgs, W, and Z bosons, as well as to search for new physics. In response to the stringent performance requirements of the vertex detector for the CEPC, a baseline vertex detector prototype was tested and characterized for the first time using a 6 GeV electron beam at DESY II Test Beam Line 21. The baseline vertex detector prototype is designed with a cylindrical barrel structure that contains six double-sided detector modules (ladders). Each side of the ladder includes TaichuPix-3 sensors based on Monolithic Active Pixel Sensor (MAPS) technology, a flexible printed circuit, and a carbon fiber support structure. Additionally, the readout electronics and the Data Acquisition system were also examined during this beam test. The performance of the prototype was evaluated using an electron beam that passed through six ladders in a perpendicular direction. The offline data analysis indicates a spatial resolution of about 5 um, with detection efficiency exceeding 99 % and an impact parameter resolution of about 5.1 um. These promising results from this baseline vertex detector prototype mark a significant step toward realizing the optimal vertex detector for the CEPC.

At the Royal Society meeting in 2023, we have mainly presented our lunar orbit array concept called DSL, and also briefly introduced a concept of a lunar surface array, LARAF. As the DSL concept had been presented before, in this article we introduce the LARAF. We propose to build an array in the far side of the Moon, with a master station which handles the data collection and processing, and 20 stations with maximum baseline of 10 km. Each station consists 12 membrane antenna units, and the stations are connected to the master station by power line and optical fiber. The array will make interferometric observation in the 0.1-50 MHz band during the lunar night, powered by regenerated fuel cells (RFCs). The whole array can be carried to the lunar surface with a heavy rocket mission, and deployed with a rover in 8 months. Such an array would be an important step in the long term development of lunar based ultralong wavelength radio astronomy. It has a sufficiently high sensitivity to observe many radio sources in the sky, though still short of the dark age fluctuations. We discuss the possible options in the power supply, data communication, deployment, etc., Comment: final submission version, 30 pages, 16 figures

The atmosphere of Triton was probed directly by observing a ground-based stellar occultation on 6 October 2022. This rare event yielded 23 positive light curves collected from 13 separate observation stations contributing to our campaign. The significance of this event lies in its potential to directly validate the modest pressure fluctuation on Triton, a phenomenon not definitively verified by previous observations, including only five stellar occultations, and the Voyager 2 radio occultation in 1989. Using an approach consistent with a comparable study, we precisely determined a surface pressure of $14.07_{-0.13}^{+0.21}~\mathrm{\mu bar}$ in 2022. This new pressure rules out any significant monotonic variation in pressure between 2017 and 2022 through direct observations, as it is in alignment with the 2017 value. Additionally, both the pressures in 2017 and 2022 align with the 1989 value. This provides further support for the conclusion drawn from the previous volatile transport model simulation, which is consistent with the observed alignment between the pressures in 1989 and 2017; that is to say, the pressure fluctuation is modest. Moreover, this conclusion suggests the existence of a northern polar cap extended down to at least $45^\circ$N$-60^\circ$N and the presence of nitrogen between $30^\circ$S and $0^\circ$., Comment: Astronomy & Astrophysics, in press. 9 pages, 2 figures, 3 tables

A digraph is strongly connected if it has a directed path from $x$ to $y$ for every ordered pair of distinct vertices $x, y$ and it is strongly $k$-connected if it has at least $k+1$ vertices and remains strongly connected when we delete any set of at most $k-1$ vertices. For a digraph $D$, we use $\delta(D)$ to denote $\mathop{\text{min}}\limits_{v\in V (D)} {|N_D^+(v)\cup N_D^-(v)|}$. In this paper, we show the following result. Let $k, l, n, n_1, n_2 \in \mathbb{N}$ with $n_1+n_2\leq n$ and $n_1,n_2\geq n/20$. Suppose that $D$ is a strongly $10^7k(k+l)^2\log(2kl$)-connected digraph of order $n$ with $\delta(D)\geq n-l$. Then there exist two disjoint subsets $V_1, V_2\in V(D)$ with $|V_1| = n_1$ and $|V_2| = n_2$ such that each of $D[V_1]$, $D[V_2]$, and $D[V_1, V_2]$ is strongly $k$-connected. In particular, $V_1$ and $V_2$ form a partition of $V(D)$ when $n_1+n_2=n$. This result improves the earlier result of Kim, K\"{u}hn, and Osthus [SIAM J. Discrete Math. 30 (2016) 895--911]., Comment: 23 pages

An oriented graph is an orientation of a simple graph. In 2009, Keevash, K\"{u}hn and Osthus proved that every sufficiently large oriented graph $D$ of order $n$ with $(3n-4)/8$ is Hamiltonian. Later, Kelly, K\"{u}hn and Osthus showed that it is also pancyclic. Inspired by this, we show that for any given constant $t$ and positive integer partition $n = n_1 + \cdots + n_t$, if $D$ is an oriented graph on $n$ vertices with minimum semidegree at least $(3n-4)/8$, then it contains $t$ disjoint cycles of lengths $n_1,\ldots , n_t$. Also, we determine the bounds on the semidegree of sufficiently large oriented graphs that are strongly Hamiltonian-connected, $k$-ordered Hamiltonian and spanning $k$-linked.

Consider large signal-plus-noise data matrices of the form $S + \Sigma^{1/2} X$, where $S$ is a low-rank deterministic signal matrix and the noise covariance matrix $\Sigma$ can be anisotropic. We establish the asymptotic joint distribution of its spiked singular values when the dimensionality and sample size are comparably large and the signals are supercritical under general assumptions concerning the structure of $(S, \Sigma)$ and the distribution of the random noise $X$. It turns out that the asymptotic distributions exhibit nonuniversality in the sense of dependence on the distributions of the entries of $X$, which contrasts with what has previously been established for the spiked sample eigenvalues in the context of spiked population models. Such a result yields the asymptotic distribution of the sample spiked eigenvalues associated with mixture models. We also explore the application of these findings in detecting mean heterogeneity of data matrices., Comment: 59 pages

We present the results of a beam test conducted on a telescope using the JadePix-3 pixel sensor, developed with TowerJazz 180 nm CMOS imaging technology. The telescope is composed of five planes, each equipped with a JadePix-3 sensor with pitches of 26 um x 16 um and 23.11 um x 16 um. In addition, it features an FPGA-based synchronous readout system. The telescope underwent testing using an electron beam with energy ranging from 4 to 6 GeV. At an electron energy of 5.4 GeV, the telescope demonstrated superior spatial resolutions of 2.6 and 2.3 um in two dimensions. By designating the central plane as the device under test, we evaluated the JadePix-3 sensor's spatial resolutions as 5.2 and 4.6 um in two dimensions, achieving a detection efficiency of over 99%.

The proposed Circular Electron Positron Collider (CEPC) imposes new challenges for the vertex detector in terms of pixel size and material budget. A Monolithic Active Pixel Sensor (MAPS) prototype called TaichuPix, based on a column drain readout architecture, has been developed to address the need for high spatial resolution. In order to evaluate the performance of the TaichuPix-3 chips, a beam test was carried out at DESY II TB21 in December 2022. Meanwhile, the Data Acquisition (DAQ) for a muti-plane configuration was tested during the beam test. This work presents the characterization of the TaichuPix-3 chips with two different processes, including cluster size, spatial resolution, and detection efficiency. The analysis results indicate the spatial resolution better than 5 $\mu m$ and the detection efficiency exceeds 99.5 % for both TaichuPix-3 chips with the two different processes.

The design of balanced ternary digital logic circuits based on memristors and conventional CMOS devices is proposed. First, balanced ternary minimum gate TMIN, maximum gate TMAX and ternary inverters are systematically designed and verified by simulation, and then logic circuits such as ternary encoders, decoders and multiplexers are designed on this basis. Two different schemes are then used to realize the design of functional combinational logic circuits such as a balanced ternary half adder, multiplier, and numerical comparator. Finally, we report a series of comparisons and analyses of the two design schemes, which provide a reference for subsequent research and development of three-valued logic circuits., Comment: 15 pages, 30 figures