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arXiv 1909.02508nucl-ex
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在$ \sqrt{s_{\mathrm{NN}}}=5.02 $ TeV和ALICE中Pb-Pb碰撞中低横动量双电子的产生

Dielectron production at low transverse momentum in Pb-Pb collisions at $ \sqrt{s_{\mathrm{NN}}}=5.02 $ TeV with ALICE

Sebastian Lehner

摘要:

双电子探测了重离子碰撞中的许多现象。这些包括轻和重味介子的生产,热辐射和相干光的生产。后一个过程的特点是在低横向对动量($ \it{p}_{\textrm{T,ee}}$)的双电子生产。提取了中心和外围Pb-Pb碰撞中双电子的横动量谱,并与相应的期望值进行了比较。在中心碰撞的数据符合预期的频谱,这是占主导地位的相关重味强子的半轻子衰变。在外围碰撞,数据表现出过剩在低\ptee相对于强子和热源。所观察到的超额产量是兼容的相干光子-光子相互作用的双电子生产的计算。

英文摘要:

Dielectrons probe a wide range of phenomena in heavy-ion collisions. These include light- and heavy-flavour meson production, thermal radiation and coherent photo-production. The latter process is distinguished by dielectron production at low transverse-pair momentum ($ \it{p}_{\textrm{T,ee}}$). Transverse momentum spectra of dielectrons in central and peripheral Pb-Pb collisions are extracted and compared to the corresponding expectations. In central collisions the data fit the expected spectrum, which is dominated by semi-leptonic decays of correlated heavy-flavour hadrons. In peripheral collisions, the data exhibit an excess at low \ptee with respect to hadronic and thermal sources. The observed excess yield is compatible with calculations for dielectron production from coherent photon-photon interactions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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