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arXiv 1602.08003hep-ph
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p-p对撞机实验中重子产生的平均横动量及其对高能强子产生物理的重要意义

Average transverse momenta of baryon production at p-p collider experiments and their crucial implications for the high energy hadroproduction physics

Olga I. Piskounova

摘要:

在夸克-胶子弦模型(QGSM)框架下,用唯象方法描述了对撞机上重子产生的横动量谱。对超子横动量分布dN/dp_t数据的分析表明,在低p_t区,质子-质子与反质子-质子碰撞中多粒子产生的动力学是不同的。在反p-p反应中,最重要的贡献来自于坡密子图的反双夸克-双夸克侧的碎裂。能量从sqrt(s)= 0.2到7范围内平均横动量与能量关系的完整研究。TeV表示随能量的轻微增长<p_t>。在Tevatron到LHC的范围内没有观察到剧烈的变化,这可能是宇宙线质子谱中“膝盖”的原因。通过对不同质量强子的平均横动量分析,揭示了强子各代间质量隙的一些规律性。这一观测结果表明,更多的强子具有以下质量13.7,37.3,101.5,276,750. GeV是预期的几何级数与顺序$δ{lnM}$ =1的质量因子。这些态可能具有超越标准模型的新的量子数。QGSM在整个x_F范围内构造重子谱的可能性在描述产生不对称性方面具有明显的优势:质子-质子碰撞中心区的重子-反重子接近,核-核反应中的重子-介子反常比,宇宙线谱中次级粒子的增长率以及最近观察到的粲重子的负不对称性LHCb实验中远快度点Y=2处的反重子谱。这项研究基于对对撞机数据的常规分析,对整个强子产生物理学领域具有许多重要意义。

英文摘要:

The phenomenological approach in the framework of Quark-Gluon String Model (QGSM) has been applied to the description of transverse momentum spectra for the baryon production at colliders. The analysis of data on hyperon transverse momentum distributions,dN/dp_t, demonstrates a difference in the dynamics of multiparticle production in proton-proton vs. antiproton-proton collisions in the region of low p_t . The most important contribution in antip-p reaction goes from fragmentation of antidiquark-diquark side of pomeron diagram. The complete study of the energy dependence of average transverse momenta for the energies from sqrt(s)= 0.2 to 7. TeV shows the slight growing of <p_t> with energy. No dramatic changes were seen on the range from Tevatron to LHC, which may be responsible for "knee" in the cosmic ray proton spectra. The average transverse momentum analysis through the different mass of hadrons reveals some regularity in the mass gaps between the hadron generations. This observation suggests that more hadrons with the following masses 13.7, 37.3, 101.5, 276, 750 ... GeV are expected by geometrical progression with the mass factor of order $δ{lnM}$=1 . These states may possess new quantum numbers beyond the Standard Model. The possibility of QGSM to construct the spectra of baryons in the whole range of x_F gives obvious advantages in the description of production asymmetries: the baryon-over-antibaryon access in the central region of proton-proton collisions, the baryon-to-meson abnormal ratios in nucleus-nucleus reactions, the growing ratios of secondary particles in cosmic ray spectra as well as the recently observed negative asymmetry for charmed baryon/antibaryon spectra at the far rapidity point Y=2 in LHCb experiment. This study, based on the routine analysis of collider data, has many crucial implications for the entire field of hadroproduction physics.

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