Experimental overview of charmonium spectroscopy

In this talk, I review the recent experimental results on charmonium spectroscopy from BESIII, Belle, BaBar and CLEOc. Below the open-charm threshold, the masses and widths of spin-singlet states eta_c, eta_c(2S), h_c are measured with high precision. Above the threshold, chi_{c2}(2P) is identified in the process gamma gamma -> chi_{c2}(2P) -> gamma D bar{D}; Evidence of X(3823) is found in the M(chi_{c1} gamma) invariant-mass distribution for B -> gamma chi_{c1} K decays, the measured properties are consistent with the missing psi_2(1^{2}D_2) state.Comment: 9 pages, 7 figures, to appear in the proceedings of The 6th International Workshop on Charm Physics (CHARM 2013

Results on B -> VV and PV Decays From Belle

I report results on $B\to VV$ and $B\to PV$ decays. The results include the measurements of the decay amplitudes and the branching fractions in the decays $B\to \phi K^*$ and $B^+\to \rho^+\rho^0$, the measurements of the branching fraction and CP asymmetry in $B^+\to \rho^+\pi^0$, and the first evidence of the decay $B^0\to\rho^0\pi^0$.Comment: Contribution to the Proceedings of the XXXIX Rencontres de Moriond (QCD and High Energy Hadronic Interactions); 5 pages, 3 figure

Effects of Impulse and Habit on Privacy Disclosure in Social Networking Sites: Moderating Role of Privacy Self-Efficacy

Prior research on privacy disclosure primarily focuses on conscious factors leading to intentional disclosure. In this study, we identify two unconscious factors, i.e., the habit of self- disclosure and the impulse of self-disclosure, which lead to users’ privacy disclosure behavior in social networking sites (SNS). We contribute to the existent literature by investigating the effects of these two factors on privacy disclosure behavior in SNS and examining a contingent factor for the effects of these two unconscious factors. Our results reveal that both habit and impulse have significant effects on privacy disclosure in SNS. The effects of habit and impulse are moderated by users’ privacy self-efficacy. Particularly, privacy self-efficacy weakens the effects of impulse on self-disclosure but strengthens the effect of habit on self-disclosure

Direct photoluminescence probing of ferromagnetism in monolayer two-dimensional CrBr3

Atomically thin magnets are the key element to build up spintronics based on two-dimensional materials. The surface nature of two-dimensional ferromagnet opens up opportunities to improve the device performance efficiently. Here, we report the intrinsic ferromagnetism in atomically thin monolayer CrBr3, directly probed by polarization resolved magneto-photoluminescence. The spontaneous magnetization persists in monolayer CrBr3 with a Curie temperature of 34 K. The development of magnons by the thermal excitation is in line with the spin-wave theory. We attribute the layer-number dependent hysteresis loops in thick layers to the magnetic domain structures. As a stable monolayer material in air, CrBr3 provides a convenient platform for fundamental physics and pushes the potential applications of the two-dimensional ferromagnetism.Comment: 27 pages, 10 figure

The Role of Psychological Ownership in Privacy Risk Compensation: A Moderated Mediation Model

Social media users tend to disclose a large amount of private information despite their high privacy concerns, which is termed as the privacy paradox in existing literature. Recent studies have found that privacy paradox can be explained by a privacy risk compensation process: users engage in privacy protection behaviors to cope with privacy threats, which in turn increase their privacy disclosure. However, it remains unclear under what condition the privacy risk compensation process can take place. In this study, we integrate the psychological ownership theory with risk compensation theory, and find that psychological ownership plays a moderation role in strengthening the privacy risk compensation. An online survey was conducted with 300 Facebook users, and our hypotheses were greatly supported. Our findings encourage social media platforms to provide more functional design elements to support users’ privacy protection behaviors and satisfy their motivational needs of psychological ownership of privacy

Optimal Strategies for Round-Trip Pairs Trading Under Geometric Brownian Motions

This paper is concerned with an optimal strategy for simultaneously trading a pair of stocks. The idea of pairs trading is to monitor their price movements and compare their relative strength over time. A pairs trade is triggered by the divergence of their prices and consists of a pair of positions to short the strong stock and to long the weak one. Such a strategy bets on the reversal of their price strengths. A round-trip trading strategy refers to opening and closing such a pair of security positions. Typical pairs-trading models usually assume a difference of the stock prices satisfies a mean-reversion equation. However, we consider the optimal pairs-trading problem by allowing the stock prices to follow general geometric Brownian motions. The objective is to trade the pairs over time to maximize an overall return with a fixed commission cost for each transaction. Initially, we allow the initial pairs position to be either long or flat. We then consider the problem when the initial pairs position may be long, flat, or short. In each case, the optimal policy is characterized by threshold curves obtained by solving the associated HJB equations.Comment: 47 pages, 5 figure