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Related papers: Interacting pion pairs in nuclear matter

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We calculate the pion self-energies in asymmetric nuclear matter in the two-loop approximation of chiral perturbation theory. We find three types of corrections beyond the well-known linear density approximation. The resulting s-wave…

Nuclear Theory · Physics 2009-11-07 N. Kaiser , W. Weise

Single pion production off nucleons is studied in the framework of relativistic baryon chiral perturbation theory at tree level with the inclusion of the terms from the dimension two effective pion-nucleon Lagrangian. The five appearing…

High Energy Physics - Phenomenology · Physics 2009-10-30 V. Bernard , N. Kaiser , Ulf-G. Meißner

A model for the pion photoproduction on nuclei in the $A\left({\gamma ,\, \pi NN} \right)B$ reaction is presented. This is an extension of our recent model for the $A\left({\gamma ,\, \pi N} \right)B$ reaction. In this approach we have…

Nuclear Theory · Physics 2015-06-16 I. V. Glavanakov , A. N. Tabachenko

The results of mid-rapidity ($0 < y < 0.8$) neutral pion spectra over an extended transverse momentum range ($1 < p_T < 12$ GeV/$c$) in $\sqrt{s_{NN}}$ = 200 GeV Au+Au collisions, measured by the STAR experiment, are presented. The neutral…

Nuclear Experiment · Physics 2010-01-27 STAR Collaboration , B. I. Abelev

We investigate the production of pions in heavy-ion collisions in the energy range of $1$ - $2$ GeV/A. The dynamics of the nucleus-nucleus collisions is described by a set of coupled transport equations of the Boltzmann-Uehling-Uhlenbeck…

Nuclear Theory · Physics 2016-09-08 S. Teis , W. Cassing , M. Effenberger , A. Hombach , U. Mosel , Gy. Wolf

We reanalyse the production of $p\bar{p}$ pairs in proton-nucleus and nucleus-nucleus collisions employing novel elementary cross sections for baryon-baryon and pion-baryon production channels based on a boson-exchange model. In contrast to…

Nuclear Theory · Physics 2009-10-30 A. Sibirtsev , W. Cassing , G. I. Lykasov , M. V. Rzjanin

A systematic study of the $\pi^-/\pi^+$ ratio in heavy-ion collisions with the same neutron/proton ratio but different masses can help single out effects of the nuclear mean field on pion production. Based on simulations using the IBUU04…

Nuclear Theory · Physics 2009-11-06 Ming Zhang , Zhi-Gang Xiao , Bao-An Li , Lie-Wen Chen , Gao-Chan Yong , Sheng-Jiang Zhu

The single-pion production reactions $pp\to d\pi^+$, $pp\to np\pi^+$ and $pp\to pp\pi^0$ were measured at a beam momentum of 0.95 GeV/c ($T_p \approx$ 400 MeV) using the short version of the COSY-TOF spectrometer. The implementation of a…

Electroproduction of pions on the nucleon near the threshold is analyzed within the framework of baryon chiral perturbation theory. We give a thorough discussion of the low--energy theorems related to charged and neutral…

High Energy Physics - Phenomenology · Physics 2016-09-01 V. Bernard , N. Kaiser , T. -S. H. Lee , Ulf-G. Meißner

We show that the tail of the chiral two-pion exchange nucleon-nucleon potential is proportional to the $\pi N$ scalar form factor and discuss how it can be translated into effective scalar meson interactions. We then construct a kernel for…

Nuclear Theory · Physics 2009-11-06 C. M. Maekawa , J. C. Pupin , M. R. Robilotta

This report describes the transitions pion -> meson_1 + meson_2 and also pion -> multi-pion for high energy pions interacting with target nuclei (Z,A). The physics interests are: A) Nuclear inelastic coherent diffraction cross sections for…

Nuclear Theory · Physics 2016-09-08 Murray A. Moinester

The Crystal Ball ($CB$) collaboration at $BNL$ has recently presented results regarding a study of the $\pi^- A \to \pi^0\pi^0 A^\prime$ reaction on $H, D, C, Al$ and $Cu$, using a nearly 4$\pi$ detector. Similar results, but for the $\pi^+…

The photoproduction of pi0pi0 and pi0pi+/- pairs off 40Ca has been investigated with the TAPS detector using the Glasgow photon tagging spectrometer at the Mainz MAMI accelerator. Data have been taken for incident photon energies in the…

We investigate p-wave pion production in nucleon-nucleon collisions up to next-to-next-to-leading order in chiral effective field theory. In particular, we show that it is possible to describe simultaneously the p-wave amplitudes in the…

Nuclear Theory · Physics 2010-10-22 V. Baru , E. Epelbaum , J. Haidenbauer , C. Hanhart , A. E. Kudryavtsev , V. Lensky , U. -G. Meissner

The doubly differential cross sections for the $^4$He$(\pi^+,\pi^-) 4p$ reaction were calculated using both a two-nucleon sequential single charge exchange model and an intranuclear cascade code. Final state interactions between the two…

Nuclear Theory · Physics 2009-11-07 M. Alqadi , W. R. Gibbs

Within the framework of the isospin-dependent Boltzmann-Uehling-Uhlenbeck(IBUU) transport model, we studied the effects of the pion potential and the symmetry energy on the pion production in the central $^{197}Au+^{197}Au$ collisions…

Nuclear Theory · Physics 2015-05-28 Wen-Mei Guo , Gao-Chan Yong , Hang Liu , Wei Zuo

Double differential production cross sections of negative and positive pions and the number of participating protons have been measured in central Au+Au collisions at 1 GeV per nucleon incident energy. At low pion energies the pi^- yield is…

We have developed a model for the N N --> N N pi pi reaction and evaluated cross sections for the different charged channels. The low energy part of those channels where the pions can be in an isospin zero state is dominated by N*…

Nuclear Theory · Physics 2007-05-23 L. Alvarez-Ruso , E. Oset , E. Hernandez

The $N\Delta\to NN$ cross sections, which take into account the $\Delta$-mass dependence of M-matrix and momentum $p_{N\Delta}$, are applied on the calculation of pion production within the framework of the UrQMD model. Our study shows that…

Nuclear Theory · Physics 2021-02-03 Yangyang Liu , Yongjia Wang , Ying Cui , Chen-Jun Xia , Zhuxia Li , Yongjing Chen , Qingfeng Li , Yingxun Zhang

With an effective Lagrangian approach, we analyze several NN \to NN\pi\pi channels by including various resonances with mass up to 1.72 GeV. For the channels with the pion pair of isospin zero, we confirm the dominance of N*(1440)\to…

Nuclear Theory · Physics 2015-03-13 Xu Cao , Bing-Song Zou , Hu-Shan Xu