Midrapidity Antiproton-to-Proton Ratio inppCollisons ats=0.9and 7 TeV Measured by the ALICE Experiment

Abstract

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.

Underlying Event measurements in pp collisions at $ \sqrt {s} = 0.9 $ and 7 TeV with the ALICE experiment at the LHC

“…Its high granularity and particle identification capabilities can be exploited for precise measurements of global event properties [18][19][20][21][22][23][24]. The central barrel covers the polar angle range 45 • −135 • (|η| < 1) and full azimuth.…”

Measurement of prompt hadron production ratios in pp collisions at $\sqrt{s} = 0.9\mbox{ and }7~\mathrm{TeV}$

“…10 Results for thep/p ratio against the rapidity loss y from LHCb. Results from other experiments are also shown [16][17][18][19][20][21]. Superimposed is a fit to the LHCb and ALICE [16] measurements that is described in the text termined to be 22.5 ± 6.0 and −0.98 ± 0.07 respectively with a χ 2 /ndf of 8.7/8.…”

“…The meanp/p ratios are given as a function of y in Table 7 and plotted in Fig. 10, with the results from other experiments [16][17][18][19][20][21] superimposed. The LHCb results cover a wider range of y than any other single experiment and significantly improve the precision of the measurements in the region y < 6.5.…”

“…Measurements have been performed of thep/p ratio in pp collisions both at the LHC [16], and at other facilities [17][18][19][20][21][22]. Studies have also been made of the production characteristics of pions, kaons and protons at the LHC at √ s = 0.9 TeV at mid-rapidity [23].…”

On the Development of Nuclear Physics in Cuba

“…125 The ITS (Inner Tracking System) system of the ALICE experiment was characterized through a reconstruction of the traces produced by radiation beams. 126,127,128,129 The load distributions as well as the momentum in the detectors used to identify loaded particles originating in protonproton 130,131,132,133,134 and Pb-Pb collisions in the LHC have also been studied.…”