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Fig 2 : Fit of the J/ invariant mass spectra in the p T range from 3 to 4 GeV/c in p-p collisions at 7 TeV. This study continues now with the J/ , which can be measure down to zero p T where CGC effects would appear more dramatically. The study of the J/ in p-p collisions is also of a first importance as a reference measurement for the p-Pb and Pb-Pb collisions [9,10]. The IPNO ALICE team is involved in the extraction of the J/ cross section at LHC energies. This study constitutes the main subject of a new PhD (started in October 2008). In this thesis we study the different fitting methods and the corrections to apply in order to calculate the cross-section (Fig 2 and 3) for different p T ranges. We also study the impact of Fig 3 : J/ acceptance and efficency map in y and p T range for the muon spectrometer in p-p collisions at 7 TeV. the number of collected J/ on the result uncertainties. This work is directly linked to the one of the Paper Preparation Group dedicated to the J/ study in p-p collisions. The deputy convener for this first paper belongs to our group. The last physics theme about the J/ concerns its expected suppression in Pb-Pb collisions relatively to p-p collisions. One of the main problem in this study is to separate the contribution of the different J/ production sources. An important part (~ 20%) comes from the B decay meson. Contrary to the ALICE central part, the muon spectrometer is unable to directly separate this contribution because there is not a forward silicon tracker to see the shifted B decay vertices. A possibility to measure indirectly this contribution in the muon spectrometer is to study 3 muons events. For example a B meson giving a J/ plus another meson, all of them decaying into muons. This kind of measurement would be a complementary one to that of the ALICE central barrel where B mesons will be extracted thanks to the high resolution silicon tracker able to measure shifted B decay vertexes. ALICE upgrades program include the possibility to add a forward silicon tracker to enable such measurement in the muon spectrometer. With the startup of the LHC, the ALICE collaboration has demonstrated is capacity to extract the physics results from the collected data very quickly. The two forthcoming years will be rich of new results which will shed a new light on quarkonia physics. References [1] First proton-proton collisions at the LHC as observed with the ALICE detector: measurement of the charged particle pseudorapidity density at sqrt(s) = 900 GeV – Eur. Phys. J. C 65 1-2 (2010) 111-125 [2] Heavy Ion Physics with ALICE - arXiv:0907.0577 – Proceeding Bormio 2009 [3] Little Bang avec ALICE – Published in Plein- Sud spéciale recherche 2008-09 [4] Numerical Simulations and Online Reconstruction of the Muon Spectrometer of AL- ICE - ALICE-INT-2009-044 [5] Low-x QCD at the LHC with the ALICE detector - Acta Physica Polonica B, vol2, N° 2, 2009 and also on arXiv:0911.1458 - [6] The Color Glass Condensate framework in p+p and p+A interactions at the ALICE experiment – proceeding SQM09 submitted to Journal of Physics G : Nuclear and Particle Physics [7] Heavy Quark production in the Color Glass Condensate framework: proton-proton and proton-nucleus collision studies in the ALICE Dimuon Forward Spectrometer - ALICE-INT- 2009-043 [8] Étude de la production de saveurs lourdes et de la multiplicité de particules chargées dans le cadre du formalisme du Color Glass Condensate pour les collisions p+p et p+Pb dans l'expérience ALICE au LHC - Magdalena Malek PhD – IPNO-T-09-03 27
NA50 updated puzzle IPNO Participation: D.Jouan, T.Wu, M.P.Comets, C.Gerschel, Y.LeBornec, M.MacCormick, X.Tarrago, L.Villatte, N.Willis Collaboration: Univ. du Piemont Oriental, LPC Aubière, IFA Bucarest, Univ. de Cagliari, CERN, LIP Lisbonne, INR Moscou, LLR Palaiseau, Univ. de Turin, IPN Lyon, YerPhI Yerevan Les derniers résultats issus des expériences réalisées jusqu’en 2000 ont considérablement augmenté la précision, à la fois des phénomènes de référence dans les réactions proton-noyaux ou deuton-noyaux, et des observations de la suppression de la production de et de ’ et de l’augmentation de celle du signatures prédites des effets de la réalisation d’un plasma de quarks et de gluons (QGP) dans les collisions d’ions lourds. 400 upsilons ont de plus été extraits des données proton noyaux. Le « puzzle » a récemment évolué grâce aux analyses des mesures effectuées en 2000: les résultats de NA50 deviennent plus compatibles avec les autres expériences, mais combinés avec les nouveaux résultats de CERES ils suggèrent une différence systématique entre les canaux leptoniques et hadroniques. NA50 in conclusion phase The NA38 and NA50 experiments have measured the muon pairs produced in heavy ion collisions at SPS along the last 20 years. Proton-nuclei (p-A) collisions have also been studied, mostly as a reference. The energy density reached in the most central A-A collisions should be sufficient to achieve a transition toward a plasma of quarks and gluons. After some years it was realized that dimuons are a favoured access to the decays of heavy quarkonia, rare productions that should be particularly sensitive to the early existence of a QGP. Indeed, thanks to the high precision of the measurements performed with various size of colliding systems, NA38 and NA50 have observed the predicted abnormal suppression of the J/ and of the ’ production, and the enhancement of the production. In 2000, the last Pb-Pb measurements have confirmed these observations with an increased precision and including more peripheral collisions. Last p-A measurements and reanalyses led to a slightly lower value for the J/ absorption cross section, 4.2 0.5 mb, and 7.7 0.9 mb for the less bound ’. About 400 bottomia ( ’ ’’) have been extracted in p-A NA50 data sets, results are consistent with low absorption observed at higher energy. production and Pb-Pb multiplicity puzzle Analyses of and production in d-C, d-U,S-U and Pb-Pb have been iteratively continued in NA50 during the last years. They are performed in tranverse mass M T domains, where the ratio should be directly related to the strange quarks fraction ( S / q ) in the medium. d-C and d-U bring a complementary estimate of the evolution of and cross sections in p-A, confirming the very different pattern compared to what is observed in ion induced collisions. Since the display of the first preliminary results in 1997, the multiplicity in Pb -Pb central collisions found by NA50 appeared higher than the one measured by NA49. In 1998 this was confirmed by new NA50 results and led to the « puzzle ». A third NA50 independent measurement was performed in 2000, with upgraded detector and using partly a different instrumental method for the minimum bias trigger, very important for the determination of the absolute M T distribution of multiplicity in central Pb-Pb collisions observed by the SPS experiments through K + K - , µ + µ – or e + e - decay channels. value of the multiplicity. The new NA50 points appear closer [1] to the NA49 ones, partly due to the 20% increase of the Particle Data Group dimuon branching ratio. In the meantime, the CERES experiment extracted multiplicities from kaons and electrons pairs. Their results are slightly lower than NA49, in an M T domain closer to NA50. In a few years the picture has then strongly evolved: the consistency between experiments improves, but still a systematic difference exists between hadronic and leptonic decays. The NA60 results in In- In also show a higher production rate than the NA49 ones in the dimuon channel, at low M T . Such SPS results with high precision combined to the forthcoming data from RHIC with high precision, and first results from LHC will open interesting perspectives in the future. 28
Page 1 and 2: EXOTIC NUCLEI STRUCTURE AND REACTIO
Page 3 and 4: in the spectra by analyzing their t
Page 5 and 6: were taken from ref. [5]. Concernin
Page 7 and 8: keV -ray with the particles and the
Page 9 and 10: the 605.9 keV line of the 74 Zn 2+
Page 11 and 12: Figure 2 a n d analysis. Figure 2 s
Page 13 and 14: ing particles was thus obtained by
Page 15 and 16: First p-p p collisions in the ALICE
Page 17: Quarkonia physics with ALICE IPNO P
Page 21 and 22: Status of the HADES experiment (I):
Page 23 and 24: Status of the HADES experiments (II
Page 25 and 26: Status of the HADES experiment (III
Page 27 and 28: Hadron physics in pbar-p p annihila
Page 29 and 30: Hadron Electrodynamics IPNO Partici
Page 31 and 32: G0 experiment at Jefferson Lab. IPN
Page 33 and 34: GEp-III and GEp-2 at Jefferson Lab
Page 35 and 36: Exotic low mass narrow baryons from
Page 37 and 38: The PVA4 parity violation experimen
Page 39 and 40: Etude des Distributions de Partons
Page 41 and 42: Latest Results from GRAAL IPNO Part
Page 43 and 44: Persistence of the Polarization in
Page 45 and 46: The northern site of the Pierre Aug
Page 47 and 48: The Pierre Auger southern Observato
Page 49 and 50: In figure 4 we plot the differentia
Page 51 and 52: THEORETICAL PHYSICS Research in the
Page 53 and 54: transfer reaction, the 34 Si(d, 3 H
Page 55 and 56: Collective excitations with SKYRME
Page 57 and 58: Pairing and nuclear incompressibili
Page 59 and 60: Pairing properties in nuclei and in
Page 61 and 62: Evaporation-residue residue cross s
Page 63 and 64: Extending the VMI model: normal and
Page 65 and 66: Alpha particle condensation in nucl
Page 67 and 68: Collective Modes in Ultracold Trapp
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Exploring key unknown neutrino prop
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Relic astrophysical and cosmologica
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After a term by term Borel resummat
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Chiral expansions of the π 0 lifet
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IPNO Participation: H. Sazdjian Eff
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fer is used to extract f + (0). We
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cleon. The spectrum becomes strongl
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A pseudo Coulombian potential in D=
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The many-body problem with an energ
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The rotational spectrum and the att
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Z-identification of very heavy nucl
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The Pegase project, a new solid sur
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But at 80 keV total energy ( 200 eV
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Isospin effects on fragment and par
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Radial collective energy and fragme
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Latent heat of the phase transition
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Alpha-particle particle condensatio
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Fluo X: Deexcitation time measureme
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ENERGY AND ENVIRONMENT The increasi
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toe/cap/y which energy access inequ
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nides. A global comparison can be p
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3D coupling of Monte-Carlo neutroni
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Fission cross sections of actinides
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Studies and synthesis of specific m
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Chemistry and Electrochemistry of T
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function of temperature. The recent
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global electron number of the redox
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(D 0 /D)-1 ln complexes of Pa(V). I
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