Open heavy flavour and J/psi production in proton-proton collisions measured with the ALICE experiment at LHC

Open heavy flavour and J/psi production are powerful tools to test pQCD calculations in proton-proton collisions in the new LHC energy regime. In addition, they provide the necessary reference for the ALICE heavy-ion program. The ALICE experiment at the LHC collected proton-proton collisions at sqrt{s} = 7 and 2.76 TeV in 2010 and 2011. We report here the latest results of open heavy flavour and J/psi production at both mid- and forward-rapidity via their various hadronic and leptonic decay channels. These include, among other topics, the first LHC result on J/psi polarization, multiplicity dependence of the J/psi production, D-meson measurement down to low transverse momentum and J/psi production from B-hadron decays. Comparisons with different theoretical models will be discussed as well.Comment: 4 pages, 4 figures, Proceedings of the Hard Probes 2012 conference, to be published on Nuclear Physics

Production du J/ dans les collisions proton-proton à 2.76 et 7 TeV dans l expérience ALICE auprès du LHC

Le plasma de quarks et de gluons (QGP) est un état de la matière nucléaire apparaissant à hautedensité d énergie. En laboratoire, il est possible de reproduire de telles conditions grâce aux collisionsd ions lourds aux énergies ultra-relativistes. ALICE (A Large Ion Collider Experiment) estl expérience du LHC dédiée à la mise en évidence du QGP.Différentes signatures ont été proposées et étudiées expérimentalement comme manifestations duQGP. Parmi celles-ci, le méson J/ joue un rôle central. Il fait partie de la famille des quarkonia,états mésoniques (Q Q) formées d un quark lourd c ou b et de son anti-quark, liés par un potentield interaction forte. En 1986, Matsui et Satz proposèrent la suppression des charmonia (états liés cc)et notamment du J/ comme signature de la formation du plasma de quarks et de gluons.ALICE peut détecter le J/ à grande rapidité (2.5 < y < 4) via le canal de désintégration en deuxmuons. Cette thèse porte sur la mesure de la production du J/ , via le canal muonique, dans lescollisions pp à une énergie dans le centre de masse de 2.76 et 7 TeV. Elle a exploité les donnéesacquises en 2010 et 2011 auprès du collisionneur LHC.Tenter d appréhender le mécanisme de production du J/ (et plus généralement du quarkonium)dans les collisions pp est un préalable nécessaire avant d aborder le degré de complexité suivantque constitue le cas des collisions noyau-noyau. Il est également un test important pour la QuantumChromo Dynamics (QCD), la théorie de l interaction forte, aux énergies très élevées du LHC.Quarkonia are meson states whose constituents are a charm or bottom quark and its correspondingantiquark (Q Q). The study of the production of such bound states in high-energy hadron collisionsrepresents an important test for the Quantum Chromo-Dynamics. Despite the fact that the quarkoniumsaga has already a 40-year history, the quarkonium production mechanism is still an open issue.Therefore, measurements at the new CERN Large Hadron Collider (LHC) energy regimes are extremelyinteresting.In this thesis, the study of inclusive J/ production in proton-proton (pp) collisions at s = 2.76and 7 TeV, obtained with the ALICE experiment, is presented. J/ mesons are measured at forwardrapidity (2.5 < y < 4), down to zero pT, via their decay into muon pairs ( + ).Quarkonium resonances also play an important role in probing the properties of the stronglyinteracting hadronic matter created, at high energy densities, in heavy-ion collisions. Under suchextreme conditions, the created system, according to QCD, undergoes a phase transition from ordinaryhadronic matter to a new state of deconfined quarks and gluons, called Quark Gluon Plasma(QGP). The ALICE experiment at CERN LHC has been specifically designed to study this state ofmatter. Quarkonia, among other probes, represents one of the most promising tools to prove the QGPformation. In order to correctly interpret the measurements of quarkonium production in heavy-ioncollisions, a solid baseline is provided by the analogous results obtained in pp collisions.Hence, the work discussed in this thesis, concerning the inclusive J/ production in pp collisions,also provides the necessary reference for the corresponding measurements performed in Pb-Pb collisionswhich were collected, by the ALICE experiment, at the very same center-of-mass energy pernucleon pair ( sNN = 2.76 TeV).PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF

Production du J/ψ dans les collisions proton-proton à 2.76 et 7 TeV dans l’expérience ALICE auprès du LHC

Quarkonia are meson states whose constituents are a charm or bottom quark and its correspondingantiquark (Q¯Q). The study of the production of such bound states in high-energy hadron collisionsrepresents an important test for the Quantum Chromo-Dynamics. Despite the fact that the quarkoniumsaga has already a 40-year history, the quarkonium production mechanism is still an open issue.Therefore, measurements at the new CERN Large Hadron Collider (LHC) energy regimes are extremelyinteresting.In this thesis, the study of inclusive J/ψ production in proton-proton (pp) collisions at √s = 2.76and 7 TeV, obtained with the ALICE experiment, is presented. J/ψ mesons are measured at forwardrapidity (2.5 < y < 4), down to zero pT, via their decay into muon pairs (μ+μ−).Quarkonium resonances also play an important role in probing the properties of the stronglyinteracting hadronic matter created, at high energy densities, in heavy-ion collisions. Under suchextreme conditions, the created system, according to QCD, undergoes a phase transition from ordinaryhadronic matter to a new state of deconfined quarks and gluons, called Quark Gluon Plasma(QGP). The ALICE experiment at CERN LHC has been specifically designed to study this state ofmatter. Quarkonia, among other probes, represents one of the most promising tools to prove the QGPformation. In order to correctly interpret the measurements of quarkonium production in heavy-ioncollisions, a solid baseline is provided by the analogous results obtained in pp collisions.Hence, the work discussed in this thesis, concerning the inclusive J/ψ production in pp collisions,also provides the necessary reference for the corresponding measurements performed in Pb-Pb collisionswhich were collected, by the ALICE experiment, at the very same center-of-mass energy pernucleon pair (√sNN = 2.76 TeV).Le plasma de quarks et de gluons (QGP) est un état de la matière nucléaire apparaissant à hautedensité d’énergie. En laboratoire, il est possible de reproduire de telles conditions grâce aux collisionsd’ions lourds aux énergies ultra-relativistes. ALICE (A Large Ion Collider Experiment) estl’expérience du LHC dédiée à la mise en évidence du QGP.Différentes signatures ont été proposées et étudiées expérimentalement comme manifestations duQGP. Parmi celles-ci, le méson J/ψ joue un rôle central. Il fait partie de la famille des quarkonia,états mésoniques (Q¯Q) formées d’un quark lourd c ou b et de son anti-quark, liés par un potentield’interaction forte. En 1986, Matsui et Satz proposèrent la suppression des charmonia (états liés cc)et notamment du J/ψ comme signature de la formation du plasma de quarks et de gluons.ALICE peut détecter le J/ψ à grande rapidité (2.5 < y < 4) via le canal de désintégration en deuxmuons. Cette thèse porte sur la mesure de la production du J/ψ, via le canal muonique, dans lescollisions pp à une énergie dans le centre de masse de 2.76 et 7 TeV. Elle a exploité les donnéesacquises en 2010 et 2011 auprès du collisionneur LHC.Tenter d’appréhender le mécanisme de production du J/ψ (et plus généralement du quarkonium)dans les collisions pp est un préalable nécessaire avant d’aborder le degré de complexité suivantque constitue le cas des collisions noyau-noyau. Il est également un test important pour la QuantumChromo Dynamics (QCD), la théorie de l’interaction forte, aux énergies très élevées du LHC

J/ψ production in proton-proton collisions at √s = 2.76 and 7 TeV in the ALICE Forward Muon Spectrometer at LHC

Quarkonia are meson states whose constituents are a charm or bottom quark and its correspondingantiquark (Q¯Q). The study of the production of such bound states in high-energy hadron collisionsrepresents an important test for the Quantum Chromo-Dynamics. Despite the fact that the quarkoniumsaga has already a 40-year history, the quarkonium production mechanism is still an open issue.Therefore, measurements at the new CERN Large Hadron Collider (LHC) energy regimes are extremelyinteresting.In this thesis, the study of inclusive J/ψ production in proton-proton (pp) collisions at √s = 2.76and 7 TeV, obtained with the ALICE experiment, is presented. J/ψ mesons are measured at forwardrapidity (2.5 < y < 4), down to zero pT, via their decay into muon pairs (μ+μ−).Quarkonium resonances also play an important role in probing the properties of the stronglyinteracting hadronic matter created, at high energy densities, in heavy-ion collisions. Under suchextreme conditions, the created system, according to QCD, undergoes a phase transition from ordinaryhadronic matter to a new state of deconfined quarks and gluons, called Quark Gluon Plasma(QGP). The ALICE experiment at CERN LHC has been specifically designed to study this state ofmatter. Quarkonia, among other probes, represents one of the most promising tools to prove the QGPformation. In order to correctly interpret the measurements of quarkonium production in heavy-ioncollisions, a solid baseline is provided by the analogous results obtained in pp collisions.Hence, the work discussed in this thesis, concerning the inclusive J/ψ production in pp collisions,also provides the necessary reference for the corresponding measurements performed in Pb-Pb collisionswhich were collected, by the ALICE experiment, at the very same center-of-mass energy pernucleon pair (√sNN = 2.76 TeV)

Comparative transcript profiling of apricot (Prunus armeniaca L.) fruit development and on-tree ripening

Considering the high degree of sequence conservation within the Rosaceae family and, in particular, among the Prunus species, we employed the first available peach oligonucleotide microarray (μPEACH 1.0) for studying the transcriptomic profile during apricot (cv. ‘Goldrich’) fruit development. Apricot fruits were harvested at three distinct developmental stages, corresponding to immature green (6 weeks before fully ripe stage), mature firm ripe (change of peel colour, 1 week before fully ripe stage) and fully ripe, namely T1, T2 and T3, respectively. When applied to μPEACH1.0, apricot target cDNAs showed significant hybridization with an average of 43% of spotted probes, validating the use of μPEACH1.0 to profile the transcriptome of apricot fruit. Microarray analyses carried out separately on peach (cv. ‘Fantasia’) and apricot fruit to profile transcriptome changes during fruit development showed that 70% of genes had the same expression pattern in both species. Such data indicate that the transcriptome is quite similar in apricot and peach fruit and also highlight the presence of species-specific transcript changes. In apricot, 400 and 74 differentially expressed genes were found during the transition from T1 to T2 and from T2 to T3, respectively. Among these, a considerable number of genes encoding IAA protein in action regulators (Aux/IAA) and heat shock proteins (HSPs) were highly up-regulated at early and late ripening, respectively. Intriguingly, the expression profiles of all considered HSPs and some of IAA protein /IAA genes showed different patterns between apricot and peach during the last stages of on-tree fruit development, suggesting the presence of diverse mechanism regulating ripening in these two close phylogenetically related species