Femtoscopy of pp collisions at $sqrt{s}$=0.9 and 7 TeV at the LHC with two-pion Bose-Einstein correlations
Femtoscopy of pp collisions at $sqrt{s}$=0.9 and 7 TeV at the LHC with two-pion Bose-Einstein correlations
复制标题
使用二π介子玻色-爱因斯坦相关性在 LHC 上 $sqrt{s}$=0.9 和 7 TeV 处的 pp 碰撞进行飞秒扫描
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发表时间：
2011
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通讯作者：
Alice Collaboration
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作者：
Alice Collaboration
我们报告了在大型强子对撞机上的ALICE实验测量的在ffiffi s p 1/4 0：9 TeV和ffiffi s p 1/4 7 TeV的pp碰撞的高统计2 π相关函数。关联函数以及提取的源半径与事件多重性和对动量成比例。在相同的多重数和对横动量范围内分析，在两个碰撞能量下的关联是相似的。一个三维的飞秒分析表明，随着事件的多重性增加，以及随着横向动量的增加，均匀性长度减少的发射区的增加。随着多样性的增加，后一种趋势变得更加明显。这表明空间-动量相关性的发展，至少对于产生高度多重粒子的碰撞来说是这样。我们认为这些趋势的背景下，以前的飞秒研究在高能强子和重子碰撞，并讨论可能的物理机制。详细分析的相关性揭示了指数形状的向外和纵向方向，而侧向仍然是高斯。这被解释为强烈衰减的共振对发射区域形状的显著贡献的结果。观察到显著的非飞秒相关性，并认为这是“迷你射流”状结构延伸到低PT的结果。它们被蒙特卡洛生成器很好地再现，并且也可以在蒙特卡罗相关性中看到。
We report on the high statistics two-pion correlation functions from pp collisions at ffiffi s p 1⁄4 0:9 TeV and ffiffi s p 1⁄4 7 TeV, measured by the ALICE experiment at the Large Hadron Collider. The correlation functions as well as the extracted source radii scale with event multiplicity and pair momentum. When analyzed in the same multiplicity and pair transverse momentum range, the correlation is similar at the two collision energies. A three-dimensional femtoscopic analysis shows an increase of the emission zone with increasing event multiplicity as well as decreasing homogeneity lengths with increasing transverse momentum. The latter trend gets more pronounced as multiplicity increases. This suggests the development of space-momentum correlations, at least for collisions producing a high multiplicity of particles. We consider these trends in the context of previous femtoscopic studies in high-energy hadron and heavyion collisions and discuss possible underlying physics mechanisms. Detailed analysis of the correlation reveals an exponential shape in the outward and longitudinal directions, while the sideward remains a Gaussian. This is interpreted as a result of a significant contribution of strongly decaying resonances to the emission region shape. Significant nonfemtoscopic correlations are observed, and are argued to be the consequence of ‘‘mini-jet’’-like structures extending to low pt. They are well reproduced by the MonteCarlo generators and seen also in þ correlations.