Department of Physics, University of Oslo, Oslo, Norway.
Phys Rev Lett. 2010 Aug 13;105(7):072002. doi: 10.1103/PhysRevLett.105.072002. Epub 2010 Aug 12.
The ratio of the yields of antiprotons to protons in pp collisions has been measured by the ALICE experiment at sqrt[s]=0.9 and 7 TeV during the initial running periods of the Large Hadron Collider. The measurement covers the transverse momentum interval 0.45<p_{t}<1.05 GeV/c and rapidity |y|<0.5. The ratio is measured to be R_{|y|<0.5}=0.957±0.006(stat)±0.014(syst) at 0.9 TeV and R_{|y|<0.5}=0.991±0.005(stat)±0.014(syst) at 7 TeV and it is independent of both rapidity and transverse momentum. The results are consistent with the conventional model of baryon-number transport and set stringent limits on any additional contributions to baryon-number transfer over very large rapidity intervals in pp collisions.
在大型强子对撞机的初始运行期间，ALICE 实验在 sqrt[s]=0.9 和 7 TeV 下测量了 pp 碰撞中反质子与质子的产额比。该测量覆盖了横动量区间 0.45<p_{t}<1.05 GeV/c 和快度 |y|<0.5。在 0.9 TeV 下，测量到的比值为 R_{|y|<0.5}=0.957±0.006(stat)±0.014(syst)，在 7 TeV 下，测量到的比值为 R_{|y|<0.5}=0.991±0.005(stat)±0.014(syst)，并且与快度和横动量无关。结果与传统的重子数输运模型一致，并对 pp 碰撞中在非常大的快度间隔上重子数转移的任何额外贡献施加了严格的限制。
