Related papers: CLAS: Double-Pion Beam Asymmetry

We present the midrapidity charged pion invariant cross sections and the ratio of $\pi^-$-to-$\pi^+$ production ($5<p_T<13$ GeV/$c$), together with the double-helicity asymmetries ($5<p_T<12$ GeV/$c$) in polarized $p$$+$$p$ collisions at…

We present recent measurements of the CKM angles alpha and gamma using data collected by the BaBar detector at the PEP-II asymmetric-energy e+ e- collider at the Stanford Linear Accelerator Center. In addition to constraints on alpha from…

A goal of the PHENIX experiment is to obtain the polarized gluon distribution function in the proton. Double helicity asymmetry in multi-particle production with polarized proton-proton collision is measured at midrapidity with RHIC Run…

We present a precise measurement of double-polarization asymmetries in the $^3\vec{\mathrm{He}}(\vec{\mathrm{e}},\mathrm{e}'\mathrm{d})$ reaction. This particular process is a uniquely sensitive probe of hadron dynamics in $^3\mathrm{He}$…

Unpolarized cross sections and double-helicity asymmetries of single-inclusive positive and negative charged hadrons at midrapidity from p+p collisions at sqrt(s)=62.4 GeV are presented. The PHENIX measurements for 1.0 < p_T < 4.5 GeV/c are…

Cross sections for the $\gamma p \to K^+ \Lambda$ have been measured at backward angles using linearly polarized photons in the range 1.50 to 2.37 GeV. In addition, the beam asymmetry for this reaction has been measured for the first time…

Differential cross sections of the reaction gamma d to K+ Sigma- (p) have been measured with the CLAS detector at Jefferson Lab using incident photons with energies between 1.1 and 3.6 GeV. This is the first complete set of strangeness…

An amplitude analysis of the $B^+\to(\pi^+\pi^-)(K^0_{\mathrm{S}}\pi^+)$ decay is performed in the mass regions $0.30 < m_{\pi^+\pi^-} < 1.10\,\mathrm{GeV}/c^2$ and $0.75 < m_{K^0_{\mathrm{S}}\pi^+} < 1.20\,\mathrm{GeV}/c^2$, using $pp$…

In this paper, J/$\psi$ polarization at mid-rapidity in $p+p$ collisions at $\sqrt{s}$ = 200 GeV measured in the STAR experiment at RHIC is reported. J/$\psi$ production is analyzed via the dielectron decay channel. J/$\psi$ polarization is…

The production of $\phi$ mesons in the reaction $e^{+}p \rightarrow e^{+} \phi p$ ($\phi \rightarrow K^{+}K^{-}$), for $7 < Q^2 < 25$ GeV$^2$ and for virtual photon-proton centre of mass energies ($W$) in the range 42-134 GeV, has been…

Using 14M $\psi(2S)$ events accumulated by BESII at the BEPC, a Covariant Helicity Amplitude Analysis is performed for $\psi(2S)\to\pi^+\pi^-J/\psi, J/\psi\to \mu^+\mu^-$. The $\pi^+\pi^-$ mass spectrum, distinctly different from phase…

The PHENIX experiment presents results from the RHIC 2005 run with polarized proton collisions at sqrt(s)=200 GeV, for inclusive \pi^0 production at mid-rapidity. Unpolarized cross section results are given for transverse momenta p_T=0.5 to…

We report a new extraction of nucleon resonance couplings using pi- photoproduction cross sections on the neutron. The world database for the process gamma n --> pi- p above 1 GeV has quadrupled with the addition of new differential cross…

The eta pi^+ pi^- final state in two-photon collisions is studied with the L3 detector at LEP, at centre-of-mass energies from 183 to 209 GeV with an integrated luminosity of 664.6/pb. The f_1(1285) meson is observed and the Q^2 dependence…

The double-helicity asymmetries ($A_{LL}$) of $\pi^{+}$ and $\pi^{-}$ production in polarized proton proton collisions are specially interesting probes of the gluon's polarization. Relative differences among $A_{LL}$ of positive, neutral,…

We present an analysis of the Lambda(1405) resonance in p+p reactions at a kinetic beam energy of 3.5 GeV, measured by the High Acceptance Di-Electron Spectrometer (HADES). The resonance is reconstructed in the two charged decay channels…

The inelastic production of J/psi mesons in e p collisions has been studied with the ZEUS detector at HERA using an integrated luminosity of 109 pb-1. The J/psi mesons were identified using the decay channel J/psi -> mu+ mu-. The…

Results on two-particle $\Delta\eta\Delta\phi$ correlations in inelastic p+p interactions at 20, 31, 40, 80, and 158~GeV/c are presented. The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN…

Polarized $p+p$ collisions provide insight into the structure of the nucleon. $A_N$ of eta mesons at forward rapidities are of particular interest, as asymmetries of other mesons observed both by PHENIX and other experiments show…

The reaction e^+e^- -> e^+e^- proton antiproton is studied with the L3 detector at LEP. The analysis is based on data collected at e^+e^- center-of-mass energies from 183 GeV to 209 GeV, corresponding to an integrated luminosity of 667…