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A. Dobrin

Publications and source records attributed to A. Dobrin.

4 recordsLinked to original sources

Data Preservation in High Energy Physics

Data preservation is a mandatory specification for any present and future experimental facility and it is a cost-effective way of doing fundamental research by exploiting unique data sets in the light of the continuously increasing theoretical understanding. This document summarizes the status of data preservation in high energy physics. The paradigms and the methodological advances are discussed from a perspective of more than ten years of experience with a structured effort at international level. The status and the scientific return related to the preservation of data accumulated at large collider experiments are presented, together with an account of ongoing efforts to ensure long-term analysis capabilities for ongoing and future experiments. Transverse projects aimed at generic solutions, most of which are specifically inspired by open science and FAIR principles, are presented as well. A prospective and an action plan are also indicated.

hep-ex

Event shape engineering with ALICE

The strong fluctuations in the initial energy density of heavy-ion collisions allow an efficient selection of events corresponding to a specific initial geometry. For such "shape engineered events", the elliptic flow coefficient, $v_2$, of unidentified charged particles, pions and (anti-)protons in Pb-Pb collisions at $\snn = 2.76$ TeV is measured by the ALICE collaboration. $v_2$ obtained with the event plane method at mid-rapidity, $|η|<0.8$, is reported for different collision centralities as a function of transverse momentum, $\pt$, out to $\pt=20$ GeV/$c$. The measured $v_2$ for the shape engineered events is significantly larger or smaller than the average which demonstrates the ability to experimentally select events with the desired shape of the initial spatial asymmetry.

nucl-ex

Elliptic flow at high transverse momentum in Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV with the ALICE experiment

An observable that can be used to better constrain the mechanism responsible for the parton energy loss is the elliptic azimuthal event anisotropy, $v_2$. We report on measurements of $v_2$ for inclusive and identified charged particles in Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV recorded by the ALICE experiment at the LHC. $v_2$ is presented for a wide range of particle transverse momentum up to $p_T=20$ GeV/c. The particle $v_2$ is finite, positive and approximately constant for $p_T>8$ GeV/c. The proton $v_2$ is higher than that of the pion up to about $p_T=8$ GeV/c. The results are compared to the measurements at lower energy reported by RHIC experiments.

nucl-ex

The ALICE TPC, a large 3-dimensional tracking device with fast readout for ultra-high multiplicity events

The design, construction, and commissioning of the ALICE Time-Projection Chamber (TPC) is described. It is the main device for pattern recognition, tracking, and identification of charged particles in the ALICE experiment at the CERN LHC. The TPC is cylindrical in shape with a volume close to 90 m^3 and is operated in a 0.5 T solenoidal magnetic field parallel to its axis. In this paper we describe in detail the design considerations for this detector for operation in the extreme multiplicity environment of central Pb--Pb collisions at LHC energy. The implementation of the resulting requirements into hardware (field cage, read-out chambers, electronics), infrastructure (gas and cooling system, laser-calibration system), and software led to many technical innovations which are described along with a presentation of all the major components of the detector, as currently realized. We also report on the performance achieved after completion of the first round of stand-alone calibration runs and demonstrate results close to those specified in the TPC Technical Design Report.

physics.ins-det