Observation of the decay psi(2S) ---> K*(892)anti-K + c.c.

title: Study of $J/ψ → ωp\overline{p}$ at BESIII

title: Experimental study of f0(975) in J / psi decays

title: Spectral measurement of electron antineutrino oscillation amplitude and frequency at Daya Bay.
abstract: A measurement of the energy dependence of antineutrino disappearance at the Daya Bay reactor neutrino experiment is reported. Electron antineutrinos (ν¯(e)) from six 2.9  GW(th) reactors were detected with six detectors deployed in two near (effective baselines 512 and 561 m) and one far (1579 m) underground experimental halls. Using 217 days of data, 41 589 (203 809 and 92 912) antineutrino candidates were detected in the far hall (near halls). An improved measurement of the oscillation amplitude sin(2)2θ(13)=0.090(-0.009)(+0.008) and the first direct measurement of the ν¯(e) mass-squared difference |Δm(ee)2|=(2.59(-0.20)(+0.19))×10(-3)  eV2 is obtained using the observed ν¯(e) rates and energy spectra in a three-neutrino framework. This value of |Δm(ee)2| is consistent with |Δm(μμ)2| measured by muon neutrino disappearance, supporting the three-flavor oscillation model.

title: Measurements of $\psi^\prime \to \bar{p} K^+ \Sigma^0$ and $\chi_{cj} \to \bar{p} K^+ \Lambda$
abstract: Using a sample of 1.06 x 10(8) psi' mesons collectedwith the BESIII detector at the BEPCII e(+)e(-) collider and chi(cJ) mesons produced via radiative transitions from the psi', we report the first observation for psi' -> (p) over barK(+)Sigma(0) + c.c. (charge conjugate), as well as improved measurements for the chi(cJ) hyperon decays chi(cJ) -> (p) over barK(+) Lambda + c.c. The branching fractions are measured to be B(psi' -> (p) over barK(+) Sigma(0) + c.c) = (1.67 +/- 0.13 +/- 0.12) x 10(-5), B(chi(c0) -> (p) over barK(+) Lambda + c.c) = (13.2 +/- 0.3 +/- 1.0) x 10(-4), B(chi(c1) -> (p) over barK(+) Lambda + c.c) = (4.5 +/- 0.2 +/- 0.4) x 10(-4), and B(chi(c2) -> (p) over barK(+) Lambda + c.c) = (8.4 +/- 0.3 +/- 0.6) x 10(-4), where the first error is statistical, and the second is systematic. In the decay of chi(c0) -> (p) over barK(+) Lambda + c.c:, an anomalous enhancement near threshold is observed in the invariant mass distribution of (p) over bar Lambda + c.c:, which cannot be explained by phase space.

title: Search for a light sterile neutrino at Daya Bay.
abstract: A search for light sterile neutrino mixing was performed with the first 217 days of data from the Daya Bay Reactor Antineutrino Experiment. The experiment's unique configuration of multiple baselines from six 2.9 GW(th) nuclear reactors to six antineutrino detectors deployed in two near (effective baselines 512 m and 561 m) and one far (1579 m) underground experimental halls makes it possible to test for oscillations to a fourth (sterile) neutrino in the 10(-3) eV(2)<|Δm(41)(2) |< 0.3 eV(2) range. The relative spectral distortion due to the disappearance of electron antineutrinos was found to be consistent with that of the three-flavor oscillation model. The derived limits on sin(2) 2θ(14) cover the 10(-3) eV(2) ≲ |Δm(41)(2)| ≲ 0.1 eV(2) region, which was largely unexplored.

title: Dielectron and diphoton channels in 2HDM
abstract: It was observed recently that [L. Randall, Mark B. Wise,  ], any particle in the Standard Model cannot decay to e + e − and γγ final states with comparably measurable branching ratios. This is also true for most extensions of the Standard Model, with the Randall–Sundrum model as an outstanding exception. In this Letter, we show that two-Higgs-Doublet-Models (2HDM) yield another possible exception if certain parameters are properly chosen. In addition, we have checked that this model survives the tests of low energy processes, including the anomalous magnetic moment and electric dipole moment of leptons, lepton-flavor-violating decays μ − → e − γ and e − e + e − .

title: Cosmological perturbations from a Spectator field during inflation
abstract: In this paper we will discuss analytically the perturbations created from a slowly rolling subdominant spectator field which decays much before the end of inflation. The quantum fluctuations of such a spectator field can seed perturbations on very large scales and explain the temperature anisotropy in the cosmic microwave background radiation with moderate non-Gaussianity, provided the relevant modes leave the Hubble patch while the spectator is slowly rolling. Furthermore, the perturbations are purely adiabatic since the inflaton decay dominates and creates all the Standard Model degrees of freedom. We will provide two examples for the spectator field potential, one with a step function profile, and the other with an inflection point. In both the cases we will compute higher order curvature perturbations, i.e. local bispectrum and trispectrum, which can be constrained by the forthcoming Planck data.

title: Neutralino Dark Matter in Gauge Mediation After Run I of LHC and LUX
abstract: Neutralino can be the dark matter candidate in the gauge-mediated supersymmetry breaking models if the conformal sequestered mechanism is assumed in the hidden sector. In this paper, we study this mechanism by using the current experimental results after the run I of LHC and LUX. By adding new Yukawa couplings between the messenger fields and Higgs fields, we find that this mechanism can predict a neutralino dark matter with correct relic density and a Higgs boson with mass around 125 GeV. All our survived points have some common features. First, the Higgs sector falls into the decoupling limit. So the properties of the light Higgs boson are similar to the predictions of the Standard Model one. Second, the correct EWSB hints a relatively small μ -term, which makes the lightest neutralino lighter than the lightest stau. So a bino–higgsino dark matter with correct relic density can be achieved. And the relatively small μ -term results in a small fine-tuning. Finally, this bino–higgsino dark matter can pass all current bounds, including both spin-independent and spin-dependent direct searches. The spin-independent cross section of our points can be examined by further experiments.

title: LHC diphoton Higgs signal predicted by little Higgs models
abstract: Little Higgs theory naturally predicts a light Higgs boson whose most important discovery channel at the LHC is the diphoton signal pp -> h -> gamma gamma. In this work, we perform a comparative study for this signal in some typical little Higgs models, namely, the littlest Higgs model, two littlest Higgs models with T-parity (named LHT-I and LHT-II), and the simplest little Higgs models. We find that compared with the standard model prediction, the diphoton signal rate is always suppressed and the suppression extent can be quite different for different models. The suppression is mild (<= 10%) in the littlest Higgs model but can be quite severe (similar or equal to 90%) in other three models. This means that discovering the light Higgs boson predicted by the little Higgs theory through the diphoton channel at the LHC will be more difficult than discovering the standard model Higgs boson.

title: Preheating and locked inflation: an analytic approach towards parametric resonance
abstract: We take an analytic approach towards the framework of parametric resonance and apply it on preheating and locked inflation. A two-scalar toy model is analytically solved for the λ2χ2 coupling for the homogenous modes. The effects of dynamic universe background and backreaction are taken into account. We show the average effect of parametric resonance to be that χ's amplitude doubles for each cycle of . Our framework partly solves the broad resonance for preheating scenario, showing two distinct stages of preheating and making the parameters of preheating analytically calculable. It is demonstrated for slowroll inflation models, preheating is terminated, if by backreaction, typically in the 5th e-fold. Under our framework, a possible inhomogeneity amplification effect is also found during preheating, which both may pose strong constraints on some inflationary models and may amplify tiny existing inhomogeneities to the desired scale. For demonstration, we show it rules out the backreaction end of preheating of the quadratic slowroll inflation model with mass m ~ 10−6. For locked inflation, parametric resonance is found to be inhibited if has more than one real component.