1,069 research outputs found
Trying to Speak: Between Politics and Aesthetics, Darmstadt 1970-1972.
No full textIn the historiography of the Darmstadt Ferienkurse, the 1970s, when they are examined at all, are generally regarded as a period of stagnation, between the fervour of serial activity in the 1950s and the resurgence of the courses in the 1980s under the banner of various inflections of New Complexity. Yet, in a period of political upheaval after 1968, dissent was felt at Darmstadt too, and protests in 1970 and 1972 saw the institution at its most politically volatile. These protest movements caused the courses’ director, Ernst Thomas, to institute wide-scale changes in their structure and content. Key roles in these protests were taken by journalists: indeed, clear parallels can be drawn between the seemingly egalitarian calls from journalists for Mitbestimmung (co-determination) at Darmstadt and the similar demands being made by their trade unions in the West German federation. Thomas’s failure to deal with journalistic pressure and his heavy-handed treatment of individual protesters (notably Reinhard Oehlschlägel) meant that, shrewd and durable though his reinvention of the courses was, it would be only in 1982, with the accession of a new director, that the press would begin to speak positively about the Darmstadt courses once more. A close reading of these two protests shows the sometime ‘citadel of the avant-garde’ at a distinctly precarious moment in its history. At the time, some felt that such protests could lead to the demise of the courses, and it was far from clear whether Thomas’s reforms would be successful. But, even within this period of uncertainty, the Darmstadt Ferienkurse were anything but stagnant
J/ψ production at midrapidity in p-Pb collisions at √sNN = 8.16 TeV
No full textThe production of inclusive, prompt and non-prompt J/ψ was studied for the first time at midrapidity (−1.37 2 GeV/c. The study of the J/ψ mesons in the dielectron channel used for the first time in ALICE online single-electron triggers from the Transition Radiation Detector, providing a data sample corresponding to an integrated luminosity of 689 ± 13 μb −1. The proton-proton reference cross section for inclusive J/ψ was obtained based on interpolations of measured data at different centre-of-mass energies and a universal function describing the p T-differential J/ψ production cross sections. The p T-differential nuclear modification factors R pPb of inclusive, prompt, and non-prompt J/ψ are consistent with unity and described by theoretical models implementing only nuclear shadowing. [Figure not available: see fulltext.
Inclusive, prompt and non-prompt J/ψ production at midrapidity in p-Pb collisions at √sNN = 5.02 TeV
No full textA measurement of inclusive, prompt, and non-prompt J/ψ production in p-Pb collisions at a nucleon-nucleon centre-of-mass energy sNN = 5.02 TeV is presented. The inclusive J/ψ mesons are reconstructed in the dielectron decay channel at midrapidity down to a transverse momentum pT = 0. The inclusive J/ψ nuclear modification factor RpPb is calculated by comparing the new results in p-Pb collisions to a recently measured proton-proton reference at the same centre-of-mass energy. Non-prompt J/ψ mesons, which originate from the decay of beauty hadrons, are separated from promptly produced J/ψ on a statistical basis for pT larger than 1.0 GeV/c. These results are based on the data sample collected by the ALICE detector during the 2016 LHC p-Pb run, corresponding to an integrated luminosity Lint = 292 ± 11 μb−1, which is six times larger than the previous publications. The total uncertainty on the pT-integrated inclusive J/ψ and non-prompt J/ψ cross section are reduced by a factor 1.7 and 2.2, respectively. The measured cross sections and RpPb are compared with theoretical models that include various combinations of cold nuclear matter effects. From the non-prompt J/ψ production cross section, the b b ̄ production cross section at midrapidity, d σbb ̄/dy, and the total cross section extrapolated over full phase space, σbb ̄, are derived. [Figure not available: see fulltext.
Energy dependence of exclusive J/ photoproduction off protons in ultra-peripheral p-Pb collisions at NN=5.02 TeV
No full textThe ALICE Collaboration has measured the energy dependence of exclusive photoproduction of J/ψ vec- tor mesons off proton targets in ultra–peripheral p–Pb colli- sions at a centre-of-mass energy per nucleon pair √sNN = 5.02 TeV. The e+ e− and μ+ μ− decay channels are used to measure the cross section as a function of the rapidity of the J/ψ in the range −2.5 < y < 2.7, correspond- ing to an energy in the γp centre-of-mass in the interval 40 < Wγ p < 550 GeV. The measurements, which are consis- tent with a power law dependence of the exclusive J/ψ pho- toproduction cross section, are compared to previous results from HERA and the LHC and to several theoretical models. They are found to be compatible with previous measure- ments
Inclusive J/psi production at forward and backward rapidity in p-Pb collisions at root s(NN)=8.16 TeV
No full textInclusive J/ψ production is studied in p-Pb interactions at a centre-of-mass energy per nucleon-nucleon collision sNN=8.16 TeV, using the ALICE detector at the CERN LHC. The J/ψ meson is reconstructed, via its decay to a muon pair, in the centre-of-mass rapidity intervals 2.03 < ycms < 3.53 and −4.46 < ycms < −2.96, where positive and negative ycms refer to the p-going and Pb-going direction, respectively. The transverse momentum coverage is pT < 20 GeV/c. In this paper, ycms- and pT-differential cross sections for inclusive J/ψ production are presented, and the corresponding nuclear modification factors RpPb are shown. Forward results show a suppression of the J/ψ yield with respect to pp collisions, concentrated in the region pT ≲ 5 GeV/c. At backward rapidity no significant suppression is observed. The results are compared to previous measurements by ALICE in p-Pb collisions at sNN=5.02 TeV and to theoretical calculations. Finally, the ratios RFB between forward- and backward-ycmsRpPb values are shown and discussed.[Figure not available: see fulltext.]
Inclusive, prompt and non-prompt J/psi production at midrapidity in p-Pb collisions at root s(NN)=5.02 TeV
No full textA measurement of inclusive, prompt, and non-prompt J/psi production in p-Pb collisions at a nucleon-nucleon centre-of-mass energy root s(NN) = 5.02 TeV is presented. The inclusive J/psi mesons are reconstructed in the dielectron decay channel at midrapidity down to a transverse momentum p(T) = 0. The inclusive J/psi nuclear modification factor R-pPb is calculated by comparing the new results in p-Pb collisions to a recently measured proton-proton reference at the same centre-of-mass energy. Non-prompt J/psi mesons, which originate from the decay of beauty hadrons, are separated from promptly produced J/psi on a statistical basis for p(T) larger than 1.0 GeV/c. These results are based on the data sample collected by the ALICE detector during the 2016 LHC p-Pb run, corresponding to an integrated luminosity L-int = 292 +/- 11 mu b(-1), which is six times larger than the previous publications. The total uncertainty on the P-T-integrated inclusive J/psi and non-prompt J/psi cross section are reduced by a factor 1.7 and 2.2, respectively. The measured cross sections and R-pPb are compared with theoretical models that include various combinations of cold nuclear matter effects. From the non-prompt J/psi production cross section, the b (b) over bar production cross section at midrapidity, d sigma(b (b) over bar)/dy, and the total cross section extrapolated over full phase space sigma(b (b) over bar) are derived
J/psi production as a function of charged-particle multiplicity in p-Pb collisions at root s(NN)=8.16 TeV
No full textInclusive J/ψ yields and average transverse momenta in p-Pb collisions at a center-of-mass energy per nucleon pair sNN = 8.16 TeV are measured as a function of the charged-particle pseudorapidity density with ALICE. The J/ψ mesons are reconstructed at forward (2.03 < ycms< 3.53) and backward (−4.46 < ycms< −2.96) center-of-mass rapidity in their dimuon decay channel while the charged-particle pseudorapidity density is measured around midrapidity. The J/ψ yields at forward and backward rapidity normalized to their respective average values increase with the normalized charged-particle pseudorapidity density, the former showing a weaker increase than the latter. The normalized average transverse momenta at forward and backward rapidity manifest a steady increase from low to high charged-particle pseudorapidity density with a saturation beyond the average value. [Figure not available: see fulltext.
Centrality dependence of J/ and (2S) production and nuclear modification in p-Pb collisions at TeV
No full textThe inclusive production of the J/ and (2S) charmonium states is studied as a function of centrality in p-Pb collisions at a centre-of-mass energy per nucleon pair TeV at the LHC. The measurement is performed in the dimuon decay channel with the ALICE apparatus in the centre-of-mass rapidity intervals (Pb-going direction) and (p-going direction), down to zero transverse momentum (). The J/ and (2S) production cross sections are evaluated as a function of the collision centrality, estimated through the energy deposited in the zero degree calorimeter located in the Pb-going direction. The -differential J/ production cross section is measured at backward and forward rapidity for several centrality classes, together with the corresponding average and values. The nuclear effects affecting the production of both charmonium states are studied using the nuclear modification factor. In the p-going direction, a suppression of the production of both charmonium states is observed, which seems to increase from peripheral to central collisions. In the Pb-going direction, however, the centrality dependence is different for the two states: the nuclear modification factor of the J/ increases from below unity in peripheral collisions to above unity in central collisions, while for the (2S) it stays below or consistent with unity for all centralities with no significant centrality dependence. The results are compared with measurements in p-Pb collisions at TeV and no significant dependence on the energy of the collision is observed. Finally, the results are compared with theoretical models implementing various nuclear matter effects.The inclusive production of the J/ψ and ψ(2S) charmonium states is studied as a function of centrality in p-Pb collisions at a centre-of-mass energy per nucleon pair = 8.16 TeV at the LHC. The measurement is performed in the dimuon decay channel with the ALICE apparatus in the centre-of-mass rapidity intervals −4.46 < y< −2.96 (Pb-going direction) and 2.03 < y< 3.53 (p-going direction), down to zero transverse momentum (p). The J/ψ and ψ(2S) production cross sections are evaluated as a function of the collision centrality, estimated through the energy deposited in the zero degree calorimeter located in the Pb-going direction. The p-differential J/ψ production cross section is measured at backward and forward rapidity for several centrality classes, together with the corresponding average 〈p〉 and values. The nuclear effects affecting the production of both charmonium states are studied using the nuclear modification factor. In the p-going direction, a suppression of the production of both charmonium states is observed, which seems to increase from peripheral to central collisions. In the Pb-going direction, however, the centrality dependence is different for the two states: the nuclear modification factor of the J/ψ increases from below unity in peripheral collisions to above unity in central collisions, while for the ψ(2S) it stays below or consistent with unity for all centralities with no significant centrality dependence. The results are compared with measurements in p-Pb collisions at = 5.02 TeV and no significant dependence on the energy of the collision is observed. Finally, the results are compared with theoretical models implementing various nuclear matter effects.[graphic not available: see fulltext]The inclusive production of the J/ and (2S) charmonium states is studied as a function of centrality in p-Pb collisions at a centre-of-mass energy per nucleon pair TeV at the LHC. The measurement is performed in the dimuon decay channel with the ALICE apparatus in the centre-of-mass rapidity intervals (Pb-going direction) and (p-going direction), down to zero transverse momentum (). The J/ and (2S) production cross sections are evaluated as a function of the collision centrality, estimated through the energy deposited in the zero degree calorimeter located in the Pb-going direction. The -differential J/ production cross section is measured at backward and forward rapidity for several centrality classes, together with the corresponding average and values. The nuclear effects affecting the production of both charmonium states are studied using the nuclear modification factor. In the p-going direction, a suppression of the production of both charmonium states is observed, which seems to increase from peripheral to central collisions. In the Pb-going direction, however, the centrality dependence is different for the two states: the nuclear modification factor of the J/ increases from below unity in peripheral collisions to above unity in central collisions, while for the (2S) it stays below or consistent with unity for all centralities with no significant centrality dependence. The results are compared with measurements in p-Pb collisions at TeV and no significant dependence on the energy of the collision is observed. Finally, the results are compared with theoretical models implementing various nuclear matter effects
Inclusive J/ψ production at forward and backward rapidity in p-Pb collisions at √sNN = 8.16 TeV
No full textInclusive J/ψ production is studied in p–Pb interactions at a centre-of-mass energy per nucleon-nucleon collision √sNN = 8.16 TeV, using the ALICE detector at the CERN LHC. The J/ψ meson is reconstructed, via its decay to a muon pair, in the centre- of-mass rapidity intervals 2.03 < ycms < 3.53 and −4.46 < ycms < −2.96, where positive and negative ycms refer to the p-going and Pb-going direction, respectively. The trans- verse momentum coverage is pT < 20 GeV/c. In this paper, ycms- and pT-differential cross sections for inclusive J/ψ production are presented, and the corresponding nuclear modi- fication factors RpPb are shown. Forward results show a suppression of the J/ψ yield with respect to pp collisions, concentrated in the region pT 5 GeV/c. At backward rapidity no significant suppression is observed. The results are compared to previous measurements by ALICE in p–Pb collisions at √sNN = 5.02 TeV and to theoretical calculations. Finally, the ratios RFB between forward- and backward-ycms RpPb values are shown and discussed
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