相关论文: Multi-pion production in the d d -> alpha X reacti…

Differences in the photoproduction of mesons on the free proton and on nuclei are expected to reveal changes in the properties of hadrons. Inclusive studies of nuclear photoabsorption have provided evidence of medium modifications. However,…

The (pi+,pd), and (pi+,dd) reactions were investigated with pions of 100 and 165 MeV kinetic energy on 6Li and 12C targets. In comparison with previously published (pi+,pp) data on the same targets and at the same beam energies, kinematic…

Recent data from the PIONS$@$MAX-lab Collaboration, measuring the total cross section of the pion incoherent photoproduction $\gamma d\to\pi^-pp$ near threshold, have been used to extract the E$_{0+}$ multipole and total cross section of…

We consider pion interactions in an effective field theory of the narrow resonance X(3872), assuming it is a weakly bound molecule of the charm mesons D^{0} \bar D^{*0} and D^{*0} \bar D^{0}. Since the hyperfine splitting of the D^{0} and…

Using the field-theory-inspired expression for the pion electromagnetic form factor F_\pi, a good description of the data in the range -10<s<1 GeV^2 is obtained upon taking into account the pseudoscalar-pseudoscalar (PP) loops. When the…

Photoproduction of neutral pions has been studied with the CBELSA/TAPS detector in the reaction $\gamma p\to p\pi^0$ for photon energies between 0.85 and 2.50 GeV. The $\pi^0$ mesons are observed in their dominant neutral decay mode:…

The interference between the Pomeron and possible odderon mechanisms of diffractive pi+pi- photoproduction results in charge asymmetry of the produced pions. The observation of charge asymmetry of pions at moderate M_{pi+pi-} will be an…

We give a full kinematical classification of all the tree-level two-pion photoproduction processes on the nucleon, which consists of seventeen diagrams. It suggests a method of analysis of two-pion data with little model bias.

The pion-production reactions $\pi^+ A \to \pi^+\pi^{\pm} A'$ were studied on $^{2}H$, $^{12}C$, $^{40}Ca$, and $^{208}Pb$ nuclei at an incident pion energy of $T_{\pi^{+}}$=283 MeV. Pions were detected in coincidence using the CHAOS…

We study the hard exclusive production of two pions in the virtual photon fragmentation region with various invariant masses including the resonance region. The amplitude is expressed in terms of two-pion light cone distribution amplitudes…

Pion production in nucleus-nucleus collisions at intermediate energies was modeled in the framework of the Isospin-dependent Boltzmann-Uehling-Uhlenbeck (IBUU) transport model. The effects of nucleon-nucleon short-range correlations in…

The leading-particle effect and the factorization property of the scattering amplitude in the impact parameter space are used to study semiclassical production of pions in the central region. The mechanism is related to the isospin-uniform…

Light, beyond-the-standard-model particles $X$ in the 1-100 MeV mass range can be produced in nuclear and hadronic reactions but would have to decay electromagnetically. We show that simple and well-understood low-energy hadronic processes…

With data taken by SELEX, which accumulated data during the 1996-1997 fixed target run at Fermilab, we study the production of charmed hadrons on copper and carbon targets with Sigma-, p, pi-, and pi+ beams. Parameterizing the production…

We discuss the elastic photo- and leptoproduction of rho^0-mesons from nucleons at Q^2 < 1 GeV^2 as studied in recent experiments at HERA and FNAL. We find that the mass distribution of the measured \pi^+\pi^- pairs is determined to a large…

Measurements of double-differential charged pion production cross-sections in interactions of 12 GeV/c protons on O_2 and N_2 thin targets are presented in the kinematic range 0.5 GeV/c < p_{\pi} < 8 GeV/c and 50 mrad < \theta_{\pi} < 250…

Inclusive measurements of pion production in proton--proton collisions in the forward direction were undertaken at 400 and 600 MeV at COSY using the Big Karl spectrograph. The high resolution in the $\pi^+$ momentum ensured that there was…

Background: Charged current pion production gives information on the axial formfactors of nucleon resonances. It also introduces a noticeable background to quasi-elastic measurements on nuclear targets. Purpose: Understand pion production…

An analysis of inclusive pion production in proton-beryllium collisions at 6.4, 12.3, and 17.5 GeV/c proton beam momentum has been performed. The data were taken by Experiment 910 at the Alternating Gradient Synchrotron at the Brookhaven…

Hybrid/exotic meson spectroscopy searches at Jefferson Lab require the accurate theoretical description of the production mechanism in peripheral photoproduction. We develop a model for $\pi\Delta$ photoproduction at high energies ($5 \leq…