Dilepton production from p-p to Ca-Ca at the Bevalac†

نویسندگان

  • H. S. Matis
  • W. Gong
  • H. Huang
  • P. N. Kirk
  • G. Igo
  • F. Manso
  • C. Naudet
  • M. Prunet
  • G. Roche
  • Z. F. Wang
  • A. Yegneswaran
چکیده

The DLS collaboration has recently completed a high statistics study of dilepton production at the Bevalac. In particular, we have measured dielectrons (e+e-) from p-p and p-d collisions to understand the basic dilepton production mechanisms in the energy range from 1.05 4.9 GeV. These data can be used to determine the basic processes which contribute to nucleon-nucleon dilepton production such as hadronic bremsstrahlung, vector meson processes, and hadronic Dalitz decay. The data show that a simple elastic bremsstrahlung calculation is insufficient to explain the data. Theoretical models are compared with the data. A new high statistics study of Ca-Ca at 1.05 A⋅GeV has been made to study the collectivity of A-A collisions.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Dilepton Production and M T -scaling at Bevalac/sis Energies *

We present a dynamical study of e + e − production in C + C and Ca + Ca collisions at BEVALAC/SIS energies on the basis of the covariant transport approach HSD employing momentum-dependent ρ-meson spectral functions that include the pion modifications in the nuclear medium as well as the polarization of the ρ-meson due to resonant ρ−N scattering. We find that the experimental data from the DLS ...

متن کامل

Low-Mass Dilepton Enhancement from in-Medium Hadronic Interactions

Based on a realistic model for the meson in free space we investigate its medium modiications through rescattering in a hot hadron gas. Within the vector dominance model the corresponding in-medium spectral function is applied to calculate e + e ? spectra in central Pb+Au as measured by the CERES collaboration at CERN-SpS energies; we also compare to results obtained with the assumption of a 'd...

متن کامل

Dilepton production in proton-proton collisions at BEVALAC energies

The dilepton production in elementary pp → eeX reactions at BEVALAC energies Tlab = 1 ÷ 5 GeV is investigated. The calculations include direct ee decays of the vector mesons ρ, ω, and φ, Dalitz decays of the π, η-, ρ-, ω-, and φ-mesons, and of the baryon resonances ∆(1232), N(1520), . . . . The subthreshold vector meson production cross sections in pp collisions are treated in a way sufficient ...

متن کامل

Dilepton production and reaction dynamics in heavy-ion collisions at SIS energies from coarse-grained transport simulations

Dilepton invariant-mass spectra for heavy-ion collisions at SIS 18 and BEVALAC energies are calculated using a coarse-grained time evolution from the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model. The coarse-graining of the microscopic simulations enables to calculate thermal dilepton emission rates by application of in-medium spectral functions from equilibrium quantum-field theo...

متن کامل

e+e− production from pp reactions at BEVALAC energies

We have performed a detailed study of dilepton production from pp collisions including the subthreshold ρ production via baryonic resonances (N(1520), N(1700)) in addition to the conventional dilepton sources as π0, η, ω and ∆ Dalitz decays and direct decays of vector mesons (ρ, ω). The role of baryonic resonances in ρ production from nucleon-nucleon collisions is studied in comparison to the D...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 1999