The ALICE Collaboration measured dielectron production as a function of the invariant mass ( m ee ), the pair transverse momentum ( p T , ee ) and the pair distance of closest approach ( DCA ee ) in pp collisions at s = 7 TeV. Prompt and non-prompt dielectron sources can be separated with the DCA ee , which will give the opportunity in heavy-ion collisions to identify thermal radiation from the medium in the intermediate-mass range dominated by contributions from open-charm and beauty hadron decays. The charm and beauty total cross sections are extracted from the data by fitting the spectra with two different MC generators, i.e., PYTHIA a leading order event generator and POWHEG a next-to-leading order event generator. Significant model dependences are observed, reflecting the sensitivity of this measurement to the heavy-flavour production mechanisms.
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机译:Alice协作测量的介质产生作为不变质量(M EE)的函数,该对横向动量(P T,EE)和在S = 7 Tev的PP碰撞中的最接近方法(DCA EE)的一对距离。提示和非提示介质源可以用DCA EE分离,这将使重离子碰撞中的机会识别来自介质的中间质量范围中的介质的热辐射,由开放式魅力和美容强调的贡献。通过用两个不同的MC发生器拟合光谱,即Pythia是领先订单事件生成器和PowHeg A Next -igning订单事件发生器,通过将光谱从数据中提取曲线和美容总横截面。观察到显着的模型依赖性,反映了这种测量对重型味道生产机制的敏感性。
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