Transverse-momentum-dependent multiplicities of charged hadrons in muon-deuteron deep inelastic scattering
Transverse-momentum-dependent multiplicities of charged hadrons in muon-deuteron deep inelastic scattering
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DOI：
10.1103/physrevd.97.032006
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发表时间：
2018-02-07
影响因子：
5
通讯作者：
Ziembicki, M.
中科院分区：
文献类型：
--
作者：
Aghasyan, M.;Alexeev, M. G.;Ziembicki, M.
使用 CERN 的 COMPASS 协作组织收集的数据对等标量目标散射的深部非弹性 μ 子中的带电强子多重性进行了半包含测量。数据涵盖以下运动学域：光子虚拟度 Q(2) > 1 (GeV/c)(2)、强子系统的不变质量 W > 5 (GeV/c)(2)、Bjorken 标度变量在 0.003 < x < 0.4 范围内、强子携带的虚光子能量分数在 0.2 < z < 0.8 范围内、以及强子横向动量相对于虚光子方向在 0.02 (GeV/c)(2) < P-hT(2) < 3 (GeV/c)(2) 范围内。多重性表示为 x、Q(2)、z 三维箱中 P-hT(2) 的函数，并与之前的半包含测量进行比较。我们探索了小 P-hT(2) 区域，即 P-hT(2) < 1 (GeV/c)(2)，其中强子横动量预计由非微扰效应产生，并且还探索了较大 P-hT(2) 区域，其中高阶微扰 QCD 的贡献预计占主导地位。使用小 P-hT(2) 处的单指数函数拟合多重性，以研究平均横向动量 < P-hT(2)> 对 x、Q(2) 和 z 的依赖性。使用各种函数形式研究了大 P-hT(2) 下多重性的幂律行为。拟合结果相当好地描述了整个测量范围内的数据。
A semi-inclusive measurement of charged hadron multiplicities in deep inelastic muon scattering off an isoscalar target was performed using data collected by the COMPASS Collaboration at CERN. The following kinematic domain is covered by the data: photon virtuality Q(2) > 1 (GeV/c)(2), invariant mass of the hadronic system W > 5 (GeV/c)(2), Bjorken scaling variable in the range 0.003 < x < 0.4, fraction of the virtual photon energy carried by the hadron in the range 0.2 < z < 0.8, and square of the hadron transverse momentum with respect to the virtual photon direction in the range 0.02 (GeV/c)(2) < P-hT(2) < 3 (GeV/c)(2). The multiplicities are presented as a function of P-hT(2) in three-dimensional bins of x, Q(2), z and compared to previous semi-inclusive measurements. We explore the small-P-hT(2) region, i.e. P-hT(2) < 1 (GeV/c)(2), where hadron transverse momenta are expected to arise from nonperturbative effects, and also the domain of larger P-hT(2), where contributions from higher-order perturbative QCD are expected to dominate. The multiplicities are fitted using a single-exponential function at small P-hT(2) to study the dependence of the average transverse momentum < P-hT(2)> on x, Q(2) and z. The power-law behavior of the multiplicities at large P-hT(2) is investigated using various functional forms. The fits describe the data reasonably well over the full measured range.