ترغب بنشر مسار تعليمي؟ اضغط هنا

A versatile method for simulating pp -> ppe+e- and dp -> pne+e-p_spec reactions

103   0   0.0 ( 0 )
 نشر من قبل Ingo Fr\\\"ohlich
 تاريخ النشر 2009
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

We have developed a versatile software package for the simulation of di-electron production in $pp$ and $dp$ collisions at SIS energies. Particular attention has been paid to incorporate different descriptions of the Dalitz decay $Delta to N e^+e^-$ via a common interface. In addition, suitable parameterizations for the virtual bremsstrahlung process $NN to NN e^+e^-$ based on one-boson exchange models have been implemented. Such simulation tools with high flexibility of the framework are important for the interpretation of the di-electron data taken with the HADES spectrometer and the design of forthcoming experiments.



قيم البحث

اقرأ أيضاً

The influence of short-range correlations (SRC) on the triple-coincidence (e,e$$pp) reactions is studied. The non-relativistic model uses a mean-field potential to account for the distortions that the escaping particles undergo. Apart from the SRC, t hat are implemented through a Jastrow ansatz with a realistic correlation function, we incorporate the contribution from pion exchange and intermediate $Delta _{33}$ currents. The (e,e$$pp) cross sections are predicted to exhibit a sizeable sensitivity to the SRC. The contribution from the two-nucleon breakup channel to the semi-exclusive $^{12}$C(e,e$$p) cross section is calculated in the kinematics of a recent NIKHEF-K experiment. In the semi-exclusive channel, a selective sensitivity in terms of the missing energy and momentum to the SRC is found.
68 - Haidong Liu 2006
We compiled the systematical measurements of anti-nucleus production in ultra-relativistic heavy ion collisions as well as those in $pp$, $pbar{p}$, $gamma p$ and $e^{+}e^{-}$ at various beam energies. The anti-baryon phase space density inferred fro m $bar{d}/bar{p}$ ratio in $A+A$, $p+A$, $pp(bar{p})$ and $gamma p$ collisions is found to follow a universal distribution as a function of center of mass of beam energy and can be described in a statistical model. We demonstrated that anti-baryon density in all the collisions is the highest when the collisions are dominated by the processes of $g+g$ or $bar{q}+g$. In $e^+e^-$ collisions at LEP, the cross section of $qbar{q}g$ is suppressed by a factor of strong coupling constant $alpha_s$ relative to $qbar{q}$. This can consistently explain the $bar{d}$ suppression observed by ALEPH relative to that in $e^+e^-to ggg$ by ARGUS. We discuss the implications to the baryon enhancement at high transverse momentum at RHIC when jet is quenched.
99 - J.E. Amaro 2003
Electron-induced one-nucleon knock-out observables are computed for moderate to high momentum transfer making use of semi-relativistic expressions for the one-body and two-body meson-exchange current matrix elements. Emphasis is placed on the semi-re lativistic form of the $Delta$-isobar exchange current and several prescriptions for the dynamical-equivalent form of the $Delta$-propagator are analyzed. To this end, the inclusive transverse response function, evaluated within the context of the semi-relativistic approach and using different prescriptions for the $Delta$-propagator, is compared with the fully relativistic calculation performed within the scheme of the relativistic Fermi gas model. It is found that the best approximation corresponds to using the traditional static $Delta$-propagator. These semi-relativistic approaches, which contain important aspects of relativity, are implemented in a distorted wave analysis of quasielastic $(e,ep)$ reactions. Final state interactions are incorporated through a phenomenological optical potential model and relativistic kinematics is assumed when calculating the energy of the ejected nucleon. The results indicate that meson exchange currents may modify substantially the $TL$ asymmetry for high missing momentum.
134 - V.D. Efros 2013
Properties of the first excited state of the nucleus 9Be are discussed based on recent (e,e) and (gamma,n) experiments. The parameters of an R-matrix analysis of different data sets are consistent with a resonance rather than a virtual state predicte d by some model calculations. The energy and the width of the resonance are deduced. Their values are rather similar for all data sets, and the energy proves to be negative. It is argued that the disagreement between the extracted B(E1) values may stem from different ways of integration of the resonance. If corrected, fair agreement between the (e,e) and one of the (gamma,n) data sets is found. A recent (gamma,n) experiment at the HIgS facility exhibits larger cross sections close to the neutron threshold which remain to be explained.
For the very first time, the correlation femtoscopy method is applied to a kinematically complete measurement of meson production in the collisions of hadrons. A two-proton correlation function was derived from the data for the pp -> ppX reaction, me asured near the threshold of eta meson production. A technique developed for the purpose of this analysis permitted to establish the correlation function separately for the production of the pp+eta and of the pp+pions systems. The shape of the two-proton correlation function for the ppeta differs from that for the pp(pions) and both do not show a peak structure opposite to results determined for inclusive measurements of heavy ion collisions.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا