核实验
The CBELSA/TAPS experiment with a longitudinally or transversely polarized target and an energy tagged, linearly or circularly polarized photon beam allows the measurement of a large set of polarization observables. Due to its good energy…
Near threshold omega meson photoproduction is studied with the CBELSA/TAPS experiment at the ELSA accelerator of Bonn University. Single as well as double polarization observables are measured using either linear or circular polarized…
$\gamma (p,K^0)\Sigma^+$ cross section was measured at the CBELSA/TAPS experiment at the ELSA electron stretcher facility. A cusp-like structure was apparent near the $K^*$ production threshold, where the cross section reduced by a factor…
The energy loss of fast partons traversing the strongly interacting matter produced in high-energy nuclear collisions is one of the most interesting observables to probe the nature of the produced medium. The multipurpose Compact Muon…
This paper presents results and plans of the NA49 and NA61/SHINE experiments at the CERN Super Proton Synchrotron concerning the study of relativistic nucleus-nucleus interactions. First, the NA49 evidence for the energy threshold of…
In studies of the dense medium produced in ultra-relativistic heavy ion collisions, photons are important hard probes, since they are not expected to be modified by the medium. The measurement of isolated prompt photon production in PbPb…
Results on two-particle angular correlations are presented in proton-proton collisions at center of mass energies of 7 TeV, over a broad range of pseudorapidity and azimuthal angle. In very high multiplicity events at 7 TeV, a pronounced…
Global variables, such as the charged particle multiplicity and the transverse energy are important observables to characterize Relativistic Heavy Ion collisions and to constrain model calculations. The charged particle multiplicity…
Event-by-event fluctuations of produced particle multiplicities are believed to be sensitive to a deconfinement phase transition and the critical point of strongly interacting matter. The NA49 collaboration has conducted a systematic study…
An observable that can be used to better constrain the mechanism responsible for the parton energy loss is the elliptic azimuthal event anisotropy, $v_2$. We report on measurements of $v_2$ for inclusive and identified charged particles in…
We present results on inclusive electrons for 1.5 $ < p_{\rm T} < $ 6 GeV/$c$ in {Pb-Pb} collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV measured with ALICE at the LHC and compare these to a cocktail of background electron sources. The excess…
Dynamical fluctuations in global conserved quantities such as baryon number, strangeness, or charge may be observed near a QCD critical point. Results from new measurements of dynamical $K/\pi$, $p/\pi$, and $K/p$ ratio fluctuations are…
We present STAR measurements of relative charm and bottom contributions to NPE from $p+p$ collisions at $\sqrt{s}$= 200 and 500 GeV energies. We report the total bottom quark production cross section from p+p collisions at $\sqrt{s}= 200$…
In this new energy regime, quarkonium provides a unique probe to study the properties of the high-density, strongly interacting system formed in the early stages of high-energy heavy-ion collisions. In ALICE, quarkonium states are…
Separation of charges along the extreme magnetic field created in non-central relativistic heavy--ion collisions is predicted to be a signature of local parity violation in strong interactions. We report on results for charge dependent two…
First results of ALICE on the production of nuclei and antinuclei in pp collisions at \surd s = 7 TeV are presented. These particles are identified using the energy loss (dE/dx) measurements in the Time Projection Chamber. The Inner…
Jets are studied in A-A collisions at RHIC and LHC with the goal to understand how they are affected by the medium and how they affect the medium. It is widely believed that hard-scattered partons lose energy when propagating through a…
Event-by-event fluctuations of the chemical composition of the hadronic system produced in nuclear collisions are believed to be sensitive to properties of the transition between confined and deconfined strongly interacting matter. In this…
The shape of the beta decay energy distribution is sensitive to the mass of the electron neutrino. Attempts to measure the endpoint shape of tritium decay have so far seen no distortion from the zero-mass form. Here we show that a new type…
Jets are produced from hard scatterings in the early stages of heavy-ion collisions. It is expected that these high-p$_T$ partons travel through the hot and dense medium before fragmenting. Therefore they are expected to suffer energy loss…