Probing Transverse Momentum Broadening via Dihadron and Hadron-jet Angular Correlations in Relativistic Heavy-ion Collisions

Dijet, dihadron, hadron-jet angular correlations have been reckoned as important probes of the transverse momentum broadening effects in relativistic nuclear collisions. When a pair of high-energy jets created in hard collisions traverse the quark-gluon plasma produced in heavy-ion collisions, they become de-correlated due to the vacuum soft gluon radiation associated with the Sudakov logarithms and the medium-induced transverse momentum broadening. For the first time, we employ the systematical resummation formalism and establish a baseline calculation to describe the dihadron and hadron-jet angular correlation data in $pp$ and peripheral $AA$ collisions where the medium effect is negligible. We demonstrate that the medium-induced broadening $\langle p_\perp^2\rangle$ and the so-called jet quenching parameter $\hat q$ can be extracted from the angular de-correlations observed in $AA$ collisions. A global $\chi^2$ analysis of dihadron and hadron-jet angular correlation data renders the best fit $\langle p_\perp^2 \rangle \sim 13~\textrm{GeV}^2$ for a quark jet at RHIC top energy. Further experimental and theoretical efforts along the direction of this work shall significantly advance the quantitative understanding of transverse momentum broadening and help us acquire unprecedented knowledge of jet quenching parameter in relativistic heavy-ion collisions.Comment: 6 pages, 3 figure

3,8-Dimethyl­quinazoline-2,4(1H,3H)-dione

In the title compound, C10H10N2O2, all non-H atoms are approximately co-planar with an r.m.s. deviation of 0.016 Å. In the crystal, mol­ecules are linked into inversion dimers by pairs of N—H⋯O hydrogen bonds. Chains along [010] are buiilt up by π–π inter­actions [centroid–centroid distance = 3.602 (1) Å] between the benzene and piperazine rings of adjacent mol­ecules

A numerically stable fragile watermarking scheme for authenticating 3D models

International audienceThis paper analyzes the numerically instable problem in the current 3D fragile watermarking schemes. Some existing fragile watermarking schemes apply the floating-point arithmetic to embed the watermarks. However, these schemes fail to work properly due to the numerically instable problem, which is common in the floating-point arithmetic. This paper proposes a numerically stable fragile watermarking scheme. The scheme views the mantissa part of the floating-point number as an unsigned integer and operates on it by the bit XOR operator. Since there is no numerical problem in the bit operation, this scheme is numerically stable. The scheme can control the watermark strength through changing the embedding parameters. This paper further discusses selecting appropriate embedding parameters to achieve good performance in terms of the perceptual invisibility and the ability to detect unauthorized attacks on the 3D models. The experimental results show that the proposed public scheme could detect attacks such as adding noise, adding/deleting faces, inserting/removing vertices, etc. The comparisons with the existing fragile schemes show that this scheme is easier to implement and use

Triply charmed baryons mass decomposition from lattice QCD

We present the first lattice QCD calculation about the mass decomposition of triply charmed baryons with $J^{P}$ as $\frac{3}{2}^{+}$ and $\frac{3}{2}^{-}$. The quark mass term $\langle H_{M} \rangle$ contributes about 66\% to the mass of $\frac{3}{2}^+$ state, which is slightly lower than that of the meson system with the same valence charm quark. Furthermore, based on our results, the total contribution of sea quarks, the gluons and the QCD anomaly accounts for about a quarter of the mass of these two triply charmed baryons. The mass difference of $\frac{3}{2}^+$ and $\frac{3}{2}^-$ states is mainly from the quark energy $\langle H_{E} \rangle$ of the QCD energy-momentum tensor. For comparison, the mass splitting is also calculated under the framework of the constituent quark model.Comment: 7 page, 14 figure

Study of a homoclinic canard explosion from a degenerate center

Canard explosion is an appealing event occurring in singularly perturbed systems. In this phenomenon, upon variation of a parameter within an exponentially small range, the amplitude of a small limit cycle increases abruptly. In this letter we analyze the canard explosion in a limit cycle related to a degenerate center (with zero Jacobian matrix). We provide a second-order approximation of the critical value of the parameter for which the canard explosion occurs. Numerical results are compared with the analytical predictions and excellent agreements are found. As in this problem the canard explosion ends in a homoclinic connection, a very good approximation for the homoclinic curve in the parameter plane is also obtained.This work has been partially supported by the Ministerio de Econom´ıa y Competitividad, Spain (MTM2017- 87915-C2-1-P), by the Ministerio de Ciencia, Innovaci´on y Universidades, Spain (PGC2018-096265-B-I00) and by the Consejer´ıa de Econom´ıa, Innovaci´on, Ciencia y Empleo de la Junta de Andaluc´ıa, Spain (projects FQM-276, TIC-0130 and UHU-1260150). B.-W.Q. is also supported by the National Natural Science Foundation of China (No. 12001110)

2-Chloro­pyridine-3-carboxamide

In the crystal structure of the title compound, C6H5ClN2O, the dihedral angle between the pyridine ring and the carboxamine group is 63.88 (8)°. Inter­molecular N—H⋯N and N—H⋯O hydrogen bonds link the mol­ecules into a two-dimensional network

Efficient multipartite entanglement purification with non-identical states

We present an efficient and general multipartite entanglement purification protocol (MEPP) for N-photon systems in Greenberger-Horne-Zeilinger (GHZ) states with non-identical input states. As a branch of entanglement purification, besides the cases of successful purification, the recurrence MEPP actually has the reusable discarded items which are usually regarded as a failure. Our protocol contains two parts for bit-flip error correction. The first one is the conventional MEPP, corresponding successful cases. The second one includes two efficient approaches, recycling purification with entanglement link and direct residual entanglement purification, that can utilize discarded items. We also make a comparison between two approaches. Which method to use depends on initial input states, and in most cases the approach of direct residual purification is optimal for it not only may obtain a higher fidelity entangled state but also it does not require additional sophisticated links. In addition, for phase-flip errors, the discarded items still have available residual entanglement in the case of different input states. With these approaches, this MEPP has a higher efficiency than all previous MEPPs and it may have potential applications in the future long-distance quantum communications and networks.Comment: 20 pages,12 figure

A broad-spectrum substrate for the human UDP-glucuronosyltransferases and its use for investigating glucuronidation inhibitors

Strong inhibition of the human UDP-glucuronosyltransferase enzymes (UGTs) may lead to undesirable effects, including hyperbilirubinaemia and drugiherb-drug interactions. Currently, there is no good way to examine the inhibitory effects and specificities of compounds toward all the important human UGTs, side-by-side and under identical conditions. Herein, we report a new, broad-spectrum substrate for human UGTs and its uses in screening and characterizing of UGT inhibitors. Following screening a variety of phenolic compound(s), we have found that methylophiopogonanone A (MOA) can be readily O-glucuronidated by all tested human UGTs, including the typical N-glucuronidating enzymes UGT1A4 and UGT2B10. MOA-O-glucuronidation yielded a single mono-O-glucuronide that was biosynthesized and purified for structural characterization and for constructing an LC-UV based MOA-O-glucuronidation activity assay, which was then used for investigating MOA-O-glucuronidation kinetics in recombinant human UGTs. The derived K-m values were crucial for selecting the most suitable assay conditions for assessing inhibitory potentials and specificity of test compound(s). Furthermore, the inhibitory effects and specificities of four known UGT inhibitors were reinvestigated by using MOA as the substrate for all tested UGTs. Collectively, MOA is a broad-spectrum substrate for the human UGTs, which offers a new and practical tool for assessing inhibitory effects and specificities of UGT inhibitors. (C) 2021 Elsevier B.V. All rights reserved.Peer reviewe