عنوان

First proton-proton collisions at the LHC as observed with the ALICE detector:

شماره

LA03x2p740

عنوان اصلي

First proton-proton collisions at the LHC as observed with the ALICE detector:

نام عام مواد

[Article]

نام نخستين پديدآور

Aamodt, K; Abel, N; Abeysekara, U; Abrahantes Quintana, A; Acero, A; Adamová, D; Aggarwal, MM; Aglieri Rinella, G; Agocs, AG; Aguilar Salazar, S; Ahammed, Z; Ahmad, A; Ahmad, N; Ahn, SU; Akimoto, R; Akindinov, A; Aleksandrov, D; Alessandro, B; Alfaro Molina, R; Alici, A; Almaráz Aviña, E; Alme, J; Alt, T; et al.

عنوان اصلي به قلم نويسنده ديگر

Measurement of the charged-particle pseudorapidity density at √s = 900 GeV

متن يادداشت

On 23rd November 2009, during the early commissioning of the CERN Large Hadron Collider (LHC), two counter-rotating proton bunches were circulated for the first time concurrently in the machine, at the LHC injection energy of 450 GeV per beam. Although the proton intensity was very low, with only one pilot bunch per beam, and no systematic attempt was made to optimize the collision optics, all LHC experiments reported a number of collision candidates. In the ALICE experiment, the collision region was centred very well in both the longitudinal and transverse directions and 284 events were recorded in coincidence with the two passing proton bunches. The events were immediately reconstructed and analyzed both online and offline. We have used these events to measure the pseudorapidity density of charged primary particles in the central region. In the range |η|<0.5, we obtain dNch/dη=3. 10±0. 13(stat.)±0. 22(syst.) for all inelastic interactions, and dNch/dη=3.51±0. 15(stat.)±0. 25(syst.) for non-single diffractive interactions. These results are consistent with previous measurements in proton-antiproton interactions at the same centre-of-mass energy at the CERN Spp̄S collider. They also illustrate the excellent functioning and rapid progress of the LHC accelerator, and of both the hardware and software of the ALICE experiment, in this early start-up phase. © CERN 2009.

تاريخ نشر

2010

عنوان

Lawrence Berkeley National Laboratory

نام الکترونيکي

نوع ماده

[Article]

کد کاربرگه

275578

سطح دسترسي

a

تكميل شده

Y