The signal of Z±(4430)Z^\pm(4430) in nucleon-antinucleon scattering

We study the production of $Z^\pm(4430)$ at a nucleon-antinucleon scattering experiment. Considering the PANDA experiment to be an ideal platform to explore the production of the charmonium and charmonim-like states, we suggest the forthcoming PANDA experiment to pay attention to the production of $Z^\pm(4430)$.Comment: 6 pages, 15 figures. Published version in EPJ

Cosmological constraints on unparticle dark matter

In unparticle dark matter (unmatter) models the equation of state of the unmatter is given by $p=\rho/(2d_U+1)$, where $d_U$ is the scaling factor. Unmatter with such equations of state would have a significant impact on the expansion history of the universe. Using type Ia supernovae (SNIa), the baryon acoustic oscillation (BAO) measurements and the shift parameter of the cosmic microwave background (CMB) to place constraints on such unmatter models we find that if only the SNIa data is used the constraints are weak. However, with the BAO and CMB shift parameter data added strong constraints can be obtained. For the $\Lambda$UDM model, in which unmatter is the sole dark matter, we find that $d_U > 60$ at 95% C.L. For comparison, in most unparticle physics models it is assumed $d_U<2$. For the $\Lambda$CUDM model, in which unmatter co-exists with cold dark matter, we found that the unmatter can at most make up a few percent of the total cosmic density if $d_U<10$, thus it can not be the major component of dark matter.Comment: Replaced with revised version. BAO data is added to make a tighter constraint. Version accepted for publication on Euro.Phys.J.

QCD sum rules analysis of the rare B_c \rar X\nu\bar{\nu} decays

Taking into account the gluon correction contributions to the correlation function, the form factors relevant to the rare B_c \rar X \nu\bar{\nu} decays are calculated in the framework of the three point QCD sum rules, where $X$ stands for axial vector particle, $AV(D_{s1})$, and vector particles, $V(D^*,D^*_s)$. The total decay width as well as the branching ratio of these decays are evaluated using the $q^2$ dependent expressions of the form factors. A comparison of our results with the predictions of the relativistic constituent quark model is presented.Comment: 21 Pages, 2 Figures and 5 Table

Virtual Effects of Split SUSY in Higgs Productions at Linear Colliders

In split supersymmetry the gauginos and higgsinos are the only supersymmetric particles possibly accessible at foreseeable colliders like the CERN Large Hadron Collider (LHC) and the International Linear Collider (ILC). In order to account for the cosmic dark matter measured by WMAP, these gauginos and higgsinos are stringently constrained and could be explored at the colliders through their direct productions and/or virtual effects in some processes. The clean environment and high luminosity of the ILC render the virtual effects of percent level meaningful in unraveling the new physics effects. In this work we assume split supersymmetry and calculate the virtual effects of the WMAP-allowed gauginos and higgsinos in Higgs productions e+e- -> Z h and e+e- -> \nu_e \bar_\nu_e h through WW fusion at the ILC. We find that the production cross section of e+e- -> Zh can be altered by a few percent in some part of the WMAP-allowed parameter space, while the correction to the WW-fusion process e+e- -> \nu_e \bar_\nu_e h is below 1%. Such virtual effects are correlated with the cross sections of chargino pair productions and can offer complementary information in probing split supersymmetry at the colliders.Comment: more discussions added (7 pages, 10 figs

Final State Interactions in Hypernuclear Decay

We present an update of the One-Meson-Exchange (OME) results for the weak decay of s- and p-shell hypernuclei (Ref. Phys. Rev. C {\bf 56}, 339 (1997)), paying special attention to the role played by final state interactions between the emitted nucleons. The present study also corrects for a mistake in the inclusion of the $K$ and $K^*$ exchange mechanisms, which substantially increases the ratio of neutron-induced to proton-induced transitions, $\Gamma_n/\Gamma_p$. With the most up-to-date model ingredients, we find that the OME approach is able to describe very satisfactorily most of the measured observables, including the ratio $\Gamma_n/\Gamma_p$.Comment: 20 pages, 2 eps figure

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Strangeness nuclear physics: a critical review on selected topics

Selected topics in strangeness nuclear physics are critically reviewed. This includes production, structure and weak decay of $\Lambda$--Hypernuclei, the $\bar K$ nuclear interaction and the possible existence of $\bar K$ bound states in nuclei. Perspectives for future studies on these issues are also outlined.Comment: 63 pages, 51 figures, accepted for publication on European Physical Journal

Weak Decay of Lambda Hypernuclei

In this review we discuss the present status of strange nuclear physics, with special attention to the weak decay of Lambda hypernuclei. The models proposed for the evaluation of the Lambda decay widths are summarized and their results are compared with the data. Despite the recent intensive investigations, the main open problem remains a sound theoretical interpretation of the large experimental values of the ratio G_n/G_p. Although recent works offer a step forward in the solution of the puzzle, further efforts must be invested in order to understand the detailed dynamics of the non-mesonic decay. Even if, by means of single nucleon spectra measurements, the error bars on G_n/G_p have been considerably reduced very recently at KEK, a clean extraction of G_n/G_p is needed. What is missing at present, but planned for the next future, are measurements of 1) nucleon energy spectra in double coincidence and 2) nucleon angular correlations: such observations allow to disentangle the nucleons produced in one- and two-body induced decays and lead to a direct determination of G_n/G_p. For the asymmetric non-mesonic decay of polarized hypernuclei the situation is even more puzzling. Indeed, strong inconsistencies appear already among data. A recent experiment obtained a positive intrinsic Lambda asymmetry parameter, a_{Lambda}, for 5_{Lambda}He. This is in complete disagreement with a previous measurement, which obtained a large and negative a_{Lambda} for p-shell hypernuclei, and with theory, which predicts a negative value moderately dependent on nuclear structure effects. Also in this case, improved experiments establishing with certainty the sign and magnitude of a_{Lambda} for s- and p-shell hypernuclei will provide a guidance for a deeper understanding of hypernuclear dynamics and decay mechanisms.Comment: 129 pages, 21 figures, Submitted to Phys. Rep

Heavy quarkonium: progress, puzzles, and opportunities

A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the $B$-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b}, and b\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K. Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D. Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A. Petrov, P. Robbe, A. Vair

Factors associated with adoption of the electronic health record system among primary care physicians

Background: A territory-wide Internet-based electronic patient record allows better patient care in different sectors. The engagement of private physicians is one of the major facilitators for implementation, but there is limited information about the current adoption level of electronic medical record (eMR) among private primary care physicians. Objective: This survey measured the adoption level, enabling factors, and hindering factors of eMR, among private physicians in Hong Kong. It also evaluated the key functions and the popularity of electronic systems and vendors used by these private practitioners. Methods: A central registry consisting of 4324 private practitioners was set up. Invitations for self-administered surveys and the completed questionnaires were sent and returned via fax, email, postal mail, and on-site clinic visits. Current users and non-users of eMR system were compared according to their demographic and practice characteristics. Student’s t tests and chi-square tests were used for continuous and categorical variables, respectively. Results: A total of 524 completed surveys (response rate 524/4405 11.90%) were collected. The proportion of using eMR in private clinics was 79.6% (417/524). When compared with non-users, the eMR users were younger (users: 48.4 years SD 10.6 years vs non-users: 61.7 years SD 10.2 years, P&lt;.001); more were female physicians (users: 80/417, 19.2% vs non-users: 14/107, 13.1%, P=.013); possessed less clinical experience (with more than20 years of practice: users: 261/417, 62.6% vs non-user: 93/107, 86.9%, P&lt;.001); fewer worked under a Health Maintenance Organization (users: 347/417, 83.2% vs non-users: 97/107, 90.7%, P&lt;.001) and more worked with practice partners (users: 126/417, 30.2% vs non-users: 4/107, 3.7%, P&lt;.001). Efficiency (379/417, 90.9%) and reduction of medical errors (229/417, 54.9%) were the major enabling factors, while patient-unfriendliness (58/107, 54.2%) and limited consultation time (54/107, 50.5%) were the most commonly reported hindering factors. The key functions of computer software among eMR users consisted of electronic patient registration system (376/417, 90.2%), drug dispensing system (328/417, 78.7%) and electronic drug labels (296/417, 71.0%). SoftLink Clinic Solution was the most popular vendor (160/417, 38.4%). Conclusions: These findings identified several physician groups who should be targeted for more assistance on eMR installation and its adoption. Future studies should address the barriers of using Internet-based eMR to enhance its adoption