Two-particle correlation triggered by high-\pt{} particles allows us to study hard scattering phenomena when full jet reconstruction is challenging. An analysis of the first ALICE pp data where charged and neutral particles isolated or not are used as trigger particles is presented. The two-particle correlation between the trigger ($t$) and the associate ($a$) particles is studied as a function of the imbalance parameter \xe=-$\vec{p}_{T_{a}} \cdot \vec{p}_{T_{t}}/\mid \vec{p}_{T_{t}}\mid ^{2}$ and interpreted in terms of jet fragmentation function.
An overview of ALICE results on the measurement of J/ψ production in pp collisions at $\sqrt{s}$ = 7 TeV collected during the LHC Run-1 period is presented, as well as first results at forward rapidity from pp collisions at $\sqrt{s}$ = 13 TeV collected during the LHC Run-2 period. In particular, the measurement of J/ψ production as a function of transverse momentum and charged-particle multiplicity are discussed and compared to theoretical model calculations.
大型离子对撞机实验（英语：Large Ion Collider Experiment）是欧洲核子研究中心未来的大型强子对撞机（LHC）实验，致力于量子色热动力学的物理学。大型强子对撞机的相对论性重离子碰撞（HIC）旨在产生夸克胶子等离子体（QGP）。这种等离子体预计将比以前的HIC实验在较低的质心能量更热，更大，更长。在ALICE实验中，在HIC第一阶段产生的短暂QGP将通过伴随探测大多数高温强相互作用物质的探针来研究。
Light vector meson production at the LHC with the ALICE detector
pp碰撞中光矢量介子产生（ρ，ω，π）的测量为研究LHC能区的软量子色动力学（QCD）过程提供了新的视角。在这种情况下的计算是基于QCD启发的唯象模型，必须调整到数据。此外，轻矢量介子的产生为高能重离子碰撞提供了参考。利用ALICE实验测量了7 TeV pp碰撞中的π和ω微分截面，以及2.76 TeV pp碰撞中的π截面，测量了它们衰变到μ子对的过程，测量的快度区间为2.5 < y < 4。
ALICE (A Large Ion Collider Experiment) at the LHC is designed for studies of nuclear matter at extreme temperatures and energy densities, so called Quark-Gluon Plasma (QGP). Two detectors for measurements of electromagnetic signals, high-granularity photon spectrometer PHOS and large acceptance electromagnetic calorimeter EMCal/DCal, are incorporated into the ALICE apparatus. In order to enhance the data sample of the high-energy part of the spectra, a dedicated triggers on high energetic photons or jets are used. High precision measurements of neutral mesons require fine energy and timing ca…
The latest results on charm-tagged jets and open-charm production obtained with \mbox{ALICE} at the LHC are presented. The baryon-to-meson ratios for $\mathrm{Λ^+_c}$, $\mathrm{Σ^{0,+,++}_c}$ and $\mathrm{Ξ^{0,+}_c}$ measured in pp collisions at $\sqrt{s}=13\ \mathrm{TeV}$ are discussed. The measurements of the jet-momentum fraction carried by the $\mathrm{D^0}$ meson and $\mathrm{Λ^+_c}$ baryon in pp collisions at $\sqrt{s}=13\ \mathrm{TeV}$ are reported, and the number of leading-parton splittings $n_{SD}$ for $\mathrm{D^0}$-tagged and inclusive jets in pp collisions at $\sqrt{s}=13\ \mathrm…
In high energy hadron collisions, direct photons can be produced in various processes and are of particular interest to study the hot QCD medium since they escape it without being affected. In these proceedings are presented the latest ALICE experiment results concerning direct photon production in proton-proton (pp), proton-lead (p-Pb) and lead-lead (Pb-Pb) collisions. All measurements agree with pQCD calculations at high transverse momentum ($p_{\text{T}}$) and show no direct photon excess at low $p_{\text{T}}$ in small systems while a low $p_{\text{T}}$ signal is found in central Pb-Pb coll…
The quark model has proven successful in describing the basic building blocks of strongly interacting particles in the Standard Model, where hadronic states consist of quarks and gluons. At the same time, Lattice QCD predicts the possibility of glueball candidates in the mass range \mbox{1550--1750} MeV/$c^2$, which have never been observed. The experimental search for the existence of mesons with no quark content is both interesting and challenging as the glueball is very likely to mix with surrounding quark-antiquark scalar meson states with the same quantum numbers. The large statistics dat…
CASTOR: The ALICE forward detector for identification of Centauros and Strangelets in Nucleus-Nucleus Collisions at the LHC
讨论了欧洲核子研究中心（CERN）大型强子对撞机（LHC）ALICE重离子实验中采用超前向探测器的物理动机。提出了一个描述核-核碰撞中半人马座火球形成和衰变的唯象模型。本文描述了CASTOR探测器，它的目的是测量相互作用的强子和光子含量，并以逐事件模式识别非常向前的、富含重子的相空间5.6 < eta < 7.2中的深穿透物体。的量热计的预期响应的模拟结果，特别是奇异的通道，提出。
The ALICE detector is well suited to measure heavy-flavour (charm and beauty) production via hadronic and semi-leptonic decay channels of heavy-flavour particles. Here an overview of heavy-flavour measurements made with the ALICE detector during Run 1 in pp and p--Pb collisions is presented and discussed.
We present here recent open heavy-flavour results from the ALICE experiment, including measurements of D-meson, $\mathrm{Λ_{c}^{+}}$ baryon and $\mathrm{Ξ_c^0}$ baryon production in pp collisions at $\sqrt{s} = 7~\mathrm{TeV}$ and p-Pb collisions at $\sqrt{s_{\mathrm{NN}}} = 5.02~\mathrm{TeV}$.
The measurements of open heavy-flavours, i.e. D mesons at central rapidity and leptons from charm and beauty decays at central and forward rapidity was studied in p-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV using the ALICE detector. The results are presented and compared to model predictions including cold nuclear matter effects.
At LHC energies, the charged-particle multiplicity dependence of particle production is a topic of considerable interest in $pp$ collisions. It has been argued that multiple partonic interactions play an important role in particle production mechanisms, not only affecting the soft processes but also the hard processes. Recently, ALICE has measured $J/ψ$ production as a function of charged-particle multiplicity to study the correlation between soft and hard processes. In this contribution, we present the $J/ψ$ production versus multiplicity for $pp$ and $p-Pb$ collisions measured by ALICE. We c…
ALICE at the LHC has a unique potential to study proton-proton collisions with the goal to probe Quantum ChromoDynamics (QCD). The apparatus was designed to reconstruct particles over a large range in transverse momentum and rapidity. In particular, quarkonia are very interesting probes of QCD, because their production mechanisms are governed by both perturbative and non-perturbative QCD processes. In ALICE, quarkonia are reconstructed via their dilepton decay channel down to zero transverse momentum. This contribution gives a short overview of quarkonium production results in proton-proton co…
Hadronic resonance production with the ALICE experiment in pp and Pb-Pb collisions at LHC energies
用ALICE实验测量了$\sqrt{s}=7$ TeV pp碰撞和$\sqrt{s_{_\mathrm{NN}}}=2.76$ TeV Pb-Pb碰撞中的强子共振$\mathrm{K}^{*}(892)^{0}$、$ϕ$（1020）和$Σ(1385)^{\pm}$。讨论了横动量谱、粒子比、核修正因子以及与模型预测的比较。此外，ALICE的结果进行了比较，在RHIC能源获得的数据。
The ALICE muon spectrometer studies the production of quarkonia and open heavy- flavour particles. It is equipped with a Trigger System composed of Resistive Plate Chambers which, by applying a transverse-momentum-based muon selection, minimises the background from light-hadron decays. The system has been continuously taking data throughout the LHC Run I; it has undergone maintenance and consolidation operations during the LHC shutdown period 1. In the first year of the LHC Run II, the system, fully recommissioned, has participated in data taking in pp and Pb/en-dashPb collisions. The performa…
Probes for the small-x parton densities and predicted effects of gluon saturation are discussed. At very low x and intermediate Q, only results on hadronic observables at the LHC are available, which do not provide unambiguous information. It is shown that the measurement of direct photons at forward rapidity at the LHC is particularly promising to provide a unique signal. We further discuss the possibilities to perform such measurements with a detector upgrade in the ALICE experiment and present the R&D activities ongoing.
We present measurements of charged jet cross sections and jet shape observables in leading jet in proton-proton (pp) collisions at sqrt(s) = 2.76 TeV with the ALICE detector at LHC. Jets are reconstructed at the midrapidity from charged particle using sequential recombination anti-kT jet finding algorithm for various R values. The results are compared to measurements from HERWIG, PHOJET and different tunes of PYTHIA6 and earlier measurements at 7 TeV.
This document describes the plans of the ALICE Collaboration for a major upgrade of its detector, referred to as ALICE 3, which is proposed for physics data-taking in the LHC Run 5 and beyond. ALICE 3 will enable an extensive programme to fully exploit the LHC for the study of the properties of strongly interacting matter with high-energy nuclear collisions. The proposed detector layout, based on advanced silicon sensors, features superb pointing resolution, excellent tracking and particle identification over a large acceptance and high readout-rate capabilities. This document discusses the pr…
