Cross-national differences in clinically significant cannabis problems: epidemiologic evidence from 'cannabis-only' smokers in the United States, Mexico, and Colombia

<p>Abstract</p> <p>Background</p> <p>Epidemiological studies show wide variability in the occurrence of cannabis smoking and related disorders across countries. This study aims to estimate cross-national variation in cannabis users' experience of clinically significant cannabis-related problems in three countries of the Americas, with a focus on cannabis users who may have tried alcohol or tobacco, but who have not used cocaine, heroin, LSD, or other internationally regulated drugs.</p> <p>Methods</p> <p>Data are from the World Mental Health Surveys Initiative and the National Latino and Asian American Study, with probability samples in Mexico (n = 4426), Colombia (n = 5,782) and the United States (USA; n = 8,228). The samples included 212 'cannabis only' users in Mexico, 260 in Colombia and 1,724 in the USA. Conditional GLM with GEE and 'exact' methods were used to estimate variation in the occurrence of clinically significant problems in cannabis only (CO) users across these surveyed populations.</p> <p>Results</p> <p>The experience of cannabis-related problems was quite infrequent among CO users in these countries, with weighted frequencies ranging from 1% to 5% across survey populations, and with no appreciable cross-national variation in general. CO users in Colombia proved to be an exception. As compared to CO users in the USA, the Colombia smokers were more likely to have experienced cannabis-associated 'social problems' (odds ratio, OR = 3.0; 95% CI = 1.4, 6.3; p = 0.004) and 'legal problems' (OR = 9.7; 95% CI = 2.7, 35.2; p = 0.001).</p> <p>Conclusions</p> <p>This study's most remarkable finding may be the similarity in occurrence of cannabis-related problems in this cross-national comparison within the Americas. Wide cross-national variations in estimated population-level cumulative incidence of cannabis use disorders may be traced to large differences in cannabis smoking prevalence, rather than qualitative differences in cannabis experiences. More research is needed to identify conditions that might make cannabis-related social and legal problems more frequent in Colombia than in the USA.</p

Nuclear dependence of the transverse single-spin asymmetry in the production of charged hadrons at forward rapidity in polarized p+pp+p, p+p+Al, and p+p+Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV

We report on the nuclear dependence of transverse single-spin asymmetries (TSSAs) in the production of positively-charged hadrons in polarized $p^{\uparrow}+p$, $p^{\uparrow}+$Al and $p^{\uparrow}+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV. The measurements have been performed at forward rapidity ($1.4<\eta<2.4$) over the range of $1.8<p_{T}<7.0$ GeV$/c$ and $0.1<x_{F}<0.2$. We observed a positive asymmetry $A_{N}$ for positively-charged hadrons in \polpp collisions, and a significantly reduced asymmetry in $p^{\uparrow}$+$A$ collisions. These results reveal a nuclear dependence of charged hadron $A_N$ in a regime where perturbative techniques are relevant. These results provide new opportunities to use \polpA collisions as a tool to investigate the rich phenomena behind TSSAs in hadronic collisions and to use TSSA as a new handle in studying small-system collisions.Comment: 303 authors from 66 institutions, 9 pages, 2 figures, 1 table. v1 is version accepted for publication in Physical Review Letters. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Measurements of double-helicity asymmetries in inclusive J/ψJ/\psi production in longitudinally polarized p+pp+p collisions at s=510\sqrt{s}=510 GeV

We report the double helicity asymmetry, $A_{LL}^{J/\psi}$, in inclusive $J/\psi$ production at forward rapidity as a function of transverse momentum $p_T$ and rapidity $|y|$. The data analyzed were taken during $\sqrt{s}=510$ GeV longitudinally polarized $p$$+$$p$ collisions at the Relativistic Heavy Ion Collider (RHIC) in the 2013 run using the PHENIX detector. At this collision energy, $J/\psi$ particles are predominantly produced through gluon-gluon scatterings, thus $A_{LL}^{J/\psi}$ is sensitive to the gluon polarization inside the proton. We measured $A_{LL}^{J/\psi}$ by detecting the decay daughter muon pairs $\mu^+ \mu^-$ within the PHENIX muon spectrometers in the rapidity range $1.2<|y|<2.2$. In this kinematic range, we measured the $A_{LL}^{J/\psi}$ to be $0.012 \pm 0.010$~(stat)~$\pm$~$0.003$(syst). The $A_{LL}^{J/\psi}$ can be expressed to be proportional to the product of the gluon polarization distributions at two distinct ranges of Bjorken $x$: one at moderate range $x \approx 0.05$ where recent RHIC data of jet and $\pi^0$ double helicity spin asymmetries have shown evidence for significant gluon polarization, and the other one covering the poorly known small-$x$ region $x \approx 2\times 10^{-3}$. Thus our new results could be used to further constrain the gluon polarization for $x< 0.05$.Comment: 335 authors, 10 pages, 4 figures, 3 tables, 2013 data. Version accepted for publication by Phys. Rev. D. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Single electron yields from semileptonic charm and bottom hadron decays in Au++Au collisions at sNN=200\sqrt{s_{NN}}=200 GeV

The PHENIX Collaboration at the Relativistic Heavy Ion Collider has measured open heavy-flavor production in minimum bias Au$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV via the yields of electrons from semileptonic decays of charm and bottom hadrons. Previous heavy-flavor electron measurements indicated substantial modification in the momentum distribution of the parent heavy quarks due to the quark-gluon plasma created in these collisions. For the first time, using the PHENIX silicon vertex detector to measure precision displaced tracking, the relative contributions from charm and bottom hadrons to these electrons as a function of transverse momentum are measured in Au$+$Au collisions. We compare the fraction of electrons from bottom hadrons to previously published results extracted from electron-hadron correlations in $p$$+$$p$ collisions at $\sqrt{s_{_{NN}}}=200$ GeV and find the fractions to be similar within the large uncertainties on both measurements for $p_T>4$ GeV/$c$. We use the bottom electron fractions in Au$+$Au and $p$$+$$p$ along with the previously measured heavy flavor electron $R_{AA}$ to calculate the $R_{AA}$ for electrons from charm and bottom hadron decays separately. We find that electrons from bottom hadron decays are less suppressed than those from charm for the region $3<p_T<4$ GeV/$c$.Comment: 432 authors, 33 pages, 23 figures, 2 tables, 2011 data. v2 is version accepted for publication by Phys. Rev. C. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Nuclear dependence of the transverse-single-spin asymmetry for forward neutron production in polarized pp++AA collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV

During 2015 the Relativistic Heavy Ion Collider (RHIC) provided collisions of transversely polarized protons with Au and Al nuclei for the first time, enabling the exploration of transverse-single-spin asymmetries with heavy nuclei. Large single-spin asymmetries in very forward neutron production have been previously observed in transversely polarized $p$$+$$p$ collisions at RHIC, and the existing theoretical framework that was successful in describing the single-spin asymmetry in $p$$+$$p$ collisions predicts only a moderate atomic-mass-number ($A$) dependence. In contrast, the asymmetries observed at RHIC in $p$$+$$A$ collisions showed a surprisingly strong $A$ dependence in inclusive forward neutron production. The observed asymmetry in $p$$+$Al collisions is much smaller, while the asymmetry in $p$$+$Au collisions is a factor of three larger in absolute value and of opposite sign. The interplay of different neutron production mechanisms is discussed as a possible explanation of the observed $A$ dependence.Comment: 315 authors, 8 pages, 4 figures, 1 table. v2 is version accepted for publication in Phys. Rev. Lett. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

L\'evy-stable two-pion Bose-Einstein correlations in sNN=200\sqrt{s_{_{NN}}}=200 GeV Au++Au collisions

We present a detailed measurement of charged two-pion correlation functions in 0%-30% centrality $\sqrt{s_{_{NN}}}=200$ GeV Au$+$Au collisions by the PHENIX experiment at the Relativistic Heavy Ion Collider. The data are well described by Bose-Einstein correlation functions stemming from L\'evy-stable source distributions. Using a fine transverse momentum binning, we extract the correlation strength parameter $\lambda$, the L\'evy index of stability $\alpha$ and the L\'evy length scale parameter $R$ as a function of average transverse mass of the pair $m_T$. We find that the positively and the negatively charged pion pairs yield consistent results, and their correlation functions are represented, within uncertainties, by the same L\'evy-stable source functions. The $\lambda(m_T)$ measurements indicate a decrease of the strength of the correlations at low $m_T$. The L\'evy length scale parameter $R(m_T)$ decreases with increasing $m_T$, following a hydrodynamically predicted type of scaling behavior. The values of the L\'evy index of stability $\alpha$ are found to be significantly lower than the Gaussian case of $\alpha=2$, but also significantly larger than the conjectured value that may characterize the critical point of a second-order quark-hadron phase transition.Comment: 448 authors, 25 pages, 11 figures, 4 tables, 2010 data. v2 is version accepted for publication in Phys. Rev. C. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm