Evidence for nuclear gluon shadowing from the ALICE measurements of PbPb ultraperipheral exclusive production

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• 作者：V. Guzey ; E. Kryshen ; M. Strikman ; M. Zhalov
• 关键词：Ultraperipheral collisions ; Nuclear shadowing ; Parton distributions in nuclei
• 刊名：Physics Letters B
• 出版年：2013
• 出版时间：7 October, 2013
• 年：2013
• 卷：726
• 期：1-3
• 页码：290-295
• 全文大小：394 K

文摘

We show that the recent ALICE measurements of exclusive production in ultraperipheral PbPb collisions at 2.76 TeV provide the first direct experimental evidence for the strong nuclear gluon shadowing in lead at . The evidence is based on the comparison of the nuclear suppression factor found in the analysis of the coherent photoproduction cross sections measured by ALICE with the nuclear gluon shadowing predicted by the global fits of nuclear parton distributions and by the leading twist theory of nuclear shadowing.