Exotic Higgs Decay h→ϕϕ→4bh\rightarrow\phi\phi\rightarrow 4b at the LHeC

We study the exotic decay of the 125 GeV Higgs boson ($h$) into a pair of light spin-0 particles ($\phi$) which subsequently decays and results in a $4b$ final state. This decay mode is well motivated in the Next to Minimal Supersymmetric Standard Model (NMSSM) and extended Higgs sector models. Instead of searching at the Large Hadron Collider (LHC) and the High Luminosity Large Hadron Collider (HL-LHC) which are beset by large Standard Model (SM) backgrounds, we investigate this decay channel at the much cleaner Large Hadron Electron Collider (LHeC). With some simple selection cuts this channel becomes nearly free of background at this $ep$ machine, in stark contrast with the situation at the (HL-)LHC. With a parton level analysis we show that for the $\phi$ mass range $[20,60]GeV$, with $100\,fb^{-1}$ luminosity the LHeC is generally capable of constraining $C_{4b}^2\equiv\kappa_{V}^2\times\text{Br}(h\rightarrow\phi\phi)\times\text{Br}^2(\phi\rightarrow b\bar{b})$ ($\kappa_{V}$ denotes the $hVV(V=W,Z)$ coupling strength relative to the SM value) to a few percent level ($95\%$ CLs). With $1\,ab^{-1}$ luminosity $C_{4b}^2$ at a few per mille level can be probed. These sensitivities are much better than the HL-LHC performance and demonstrate the important role expected to be played by the LHeC in probing exotic Higgs decay processes, in addition to the already proposed invisible Higgs decay channel.Comment: 10 pages, 5 figures. Version accepted by EPJC. Tables and figures updated after correcting a mistake in signal event generation. Results essentially unchange

Evolution of pore structure, submaceral composition and produced gases of two Chinese coals during thermal treatment

This research was funded by the Research Program for Excellent Doctoral Dissertation Supervisor of Beijing (grant no. YB20101141501), the Fundamental Research Funds for Central Universities (grant no. 35832015136) and Key Project of Coal-based Science and Technology in Shanxi Province-CBM accumulation model and reservoir evaluation in Shanxi province (grant no. MQ2014-01).Peer reviewedPostprin

供精人工授精308例患者术后护理体会

Objective: To discuss artificial insemination lie on your back after the surgery time and to obtain ideal pregnancy outcome. Methods: Thisstudy retrospectively analyzed patients undergoing for pure artificial insemination in in Renji Hospital,Shanghai Jiao Tong University School, during 2012-2013. According to different patients after artificial insemination lie low time into three groups，D30min group: 102 cases, D45min groups: 120 cases, D60min groups: 86 cases, comparison of three groups of ages,basal FSH, surgery date intrauterine membrane thickness, statistical analysis of three groups of clinical pregnancy rate, early abortion rate and live-birth rate if there is a difference. Results: Three groups of ages, basal FSH, surgery date intrauterine membrane thickness were of no statistical difference. D30min group, the clinical pregnancy rate was 19.6%, early abortion rate was 5%, the live birth rate was 18.6%. D45min groups, the clinical pregnancy rate was 19.2%, the early abortion rate was 4.3%, the live birth rate was 18.3%. D60min groups,the clinical pregnancy rate was 19.8%, the early abortion rate was 0%,the live birth rate was19.8%. P > 0.05, found no statistical differences. Conclusion: Patients lie long does not increase the clinical pregnancy rate since the implementation of artificial insemination postoperatively. Lying down for 30 minutes enables the patients to achieve ideal artificial insemination pregnancy effect. 目的  探讨人工授精手术后平躺时间与取得理想妊娠结局的关系。方法  本研究回顾性分析于2012—2013年于上海交通大学医学院附属仁济医院接受供精人工授精的患者，根据患者人工授精术后平躺时间不同分成三组，D30min组：102例，D45min组：120例，D60min组：86例，比较三组的女方年龄，基础FSH，手术日子宫内膜厚度，统计分析三组临床妊娠率，早期流产率和活产率是否存在差异。结果  三组的女方年龄，基础FSH，手术日子宫内膜厚度均差异无统计学意义。D30min组临床妊娠率为19.6%，早期流产率5%，活产率为18.6%；D45min组临床妊娠率为19.2%，早期流产率4.3%，活产率为18.3%；D60min组临床妊娠率为19.8%，早期流产率0%，活产率为19.8%。P值均>0.05，未发现统计学差异。结论  实施人工受精术后，患者平躺时间延长并不会增加临床妊娠率，术后平躺30min已能够达到人工授精理想的妊娠效果。

A Packet Dropping Mechanism for Efficient Operation of M/M/1 Queues with Selfish Users

We consider a fundamental game theoretic problem concerning selfish users contributing packets to an M/M/1 queue. In this game, each user controls its own input rate so as to optimize a desired tradeoff between throughput and delay. We first show that the original game has an inefficient Nash Equilibrium (NE), with a Price of Anarchy (PoA) that scales linearly or worse in the number of users. In order to improve the outcome efficiency, we propose an easily implementable mechanism design whereby the server randomly drops packets with a probability that is a function of the total arrival rate. We show that this results in a modified M/M/1 queueing game that is an ordinal potential game with at least one NE. In particular, for a linear packet dropping function, which is similar to the Random Early Detection (RED) algorithm used in Internet Congestion Control, we prove that there is a unique NE. We also show that the simple best response dynamic converges to this unique equilibrium. Finally, for this scheme, we prove that the social welfare (expressed either as the summation of utilities of all players, or as the summation of the logarithm of utilities of all players) at the equilibrium point can be arbitrarily close to the social welfare at the global optimal point, i.e. the PoA can be made arbitrarily close to 1. We also study the impact of arrival rate estimation error on the PoA through simulations.Comment: This work is an extended version of the conference paper: Y. Gai, H. Liu and B. Krishnamachari, "A packet dropping-based incentive mechanism for M/M/1 queues with selfish users", the 30th IEEE International Conference on Computer Communications (IEEE INFOCOM 2011), China, April, 201

Electrical Control of Magnetization in Charge-ordered Multiferroic LuFe2O4

LuFe2O4 exhibits multiferroicity due to charge order on a frustrated triangular lattice. We find that the magnetization of LuFe2O4 in the multiferroic state can be electrically controlled by applying voltage pulses. Depending on with or without magnetic fields, the magnetization can be electrically switched up or down. We have excluded thermal heating effect and attributed this electrical control of magnetization to an intrinsic magnetoelectric coupling in response to the electrical breakdown of charge ordering. Our findings open up a new route toward electrical control of magnetization.Comment: 14 pages, 5 figure