相关论文: Hadron Mass Effects: Kaons at HERMES vs. COMPASS
To make precision particle mass measurements in charged spectrometers detailed understanding of the influence of detector effects is critical. In this paper the influence of detector-related uncertainties on the determination of the parent…
There is currently enormous interest in the investigation of how hadron properties may be altered by immersion in matter. There is strong evidence of a reduction in the mass of the rho meson from relativistic heavy ion collisions as well as…
We discuss some experimental and theoretical results on single spin asymmetries (SSA) in high energy lepton-hadron and hadron-hadron reactions. In particular, recent results on meson SSA obtained by HERMES are considered in detail. We also…
We investigate in stable strange hadronic matter (SHM) the modification of the masses of the scalar ($\sigma$, $\sigma^*$) and the vector ($\omega$, $\phi$) mesons. The baryon ground state is treated in the relativistic Hartree…
We recently presented a method of analyzing invariant-mass spectra of kaon pairs resulting from decay of $\phi$ mesons produced in high-energy heavy-ion collisions. It can be used to extract the shifts in the mass and the width ($\Delta M$…
We study the effects of periodic matter in kaon regeneration, motivated by the possibility of parametric resonance in neutrino oscillations. The large imaginary parts of the forward kaon-nucleon scattering amplitudes and the decay width…
In this paper a discussion is made of the article by the HERMES Collaboration, Phys.Lett. B666,446, where several important results concerning strange quark properties in the nucleon were presented. By analysing the sum of K+-…
The observable consequences of a lowering of the restmasses of vector mesons on dilepton spectra in the SIS energy regime (HADES) and on photoabsorption cross sections on nuclei are studied in a transporttheoretical framework. We also…
Single spin asymmetries in semi-inclusive deep-inelastic scattering off transversely polarized targets give information on, among other fascinating effects, a pseudo time-reversal odd parton distribution function, the 'Sivers function'. In…
We present a systematic study of the kaon to pion multiplicity ratios (K+/pi+ and K-/pi-) in heavy-ion collisions from AGS to RHIC energy using the Relativistic Quantum Molecular Dynamics (RQMD) model. The model satisfactorily describes the…
Recent calculations of the two-loop electroweak effects enhanced by powers of the top mass have been implemented in the main electroweak libraries and have an important effect on the indirect determination of the Higgs mass MH. I briefly…
Preliminary results obtained by the COMPASS experiment for longitudinal-spin-dependent azimuthal asymmetries in single-hadron muoproduction off protons are presented for the first time. The analysis was carried out on the full data sample…
Power corrections to hadronic event shapes are estimated using a recently suggested relationship between perturbative and non-perturbative effects in QCD. The infrared cutoff dependence of perturbative calculations is related to…
We present results for the leading order QCD correction to the anomalous magnetic moment of the muon including the first two generations of quarks as dynamical degrees of freedom. Several light quark masses are examined in order to yield a…
The quark potential model for mesons and its extension for hybrid mesons are used to study the effects of radial excitations on the masses, sizes and radial wave functions at the origin for conventional and hybrid charmonium mesons. These…
The study of transverse spin and transverse momentum effects is an important part of the scientific program of COMPASS, a fixed target experiment at the CERN SPS. For these studies a 160 GeV/c momentum muon beam is scattered on a…
We study the $K^*$ meson dissociation in heavy ion collisions during the hadron gas phase. We use the production and absorption cross sections of the $K^*$ and $K$ mesons in a hadron gas, which were calculated in a previous work. We compute…
We present a method of analyzing invariant-mass spectra of kaon pairs resulting from decay of $\phi$ mesons produced in high-energy heavy-ion collisions. It can be used to extract the shifts in the mass and the width ($\Delta M$ and $\Delta…
Several different effects in electroweak quantum corrections are explored separately through the latest data on the weak-boson masses. The leading-log approximation, the improved-Born approximation and the non-decoupling top-quark effects…
We compute the electromagnetic mass difference for the $B$-, $D$- and $K$-mesons using QCD sum rules with double dispersion relations. For the $B$- and $D$-mesons we also compute the linear quark mass correction, whereas for the $K$ the…