Browsing by Subject "SIDE"

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  • Lappi, T. (2015)
    Recent experimental results have revealed a surprisingly rich structure of multiparticle azimuthal correlations in high energy proton-nucleus collisions. Final state collective effects can be responsible for many of the observed effects, but it has recently been argued that a part of these correlations are present already in the wavefunctions of the colliding particles. We evaluate the momentum space 2-particle cumulant azimuthal anisotropy coefficients v(n){2}, n = 2, 3, 4 from fundamental representation Wilson line distributions describing the high energy nucleus. These would correspond to the flow coefficients in very forward proton-nucleus scattering. We find significant differences between Wilson lines from the MV model and from JIMWLK evolution. The magnitude and qualitative transverse momentum dependence of the v(n){2} values suggest that the fluctuations present in the initial fields are a significant contribution to the observed anisotropies. (C) 2015 The Author. Published by Elsevier B.V.
  • The CMS collaboration; Sirunyan, A. M.; Eerola, P.; Kirschenmann, H.; Pekkanen, J.; Voutilainen, M.; Havukainen, J.; Heikkilä, J. K.; Järvinen, T.; Karimäki, V.; Kinnunen, R.; Lampén, T.; Lassila-Perini, K.; Laurila, S.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Siikonen, H.; Tuominen, E.; Tuominiemi, J.; Tuuva, T. (2018)
    The elliptic azimuthal anisotropy coefficient (upsilon(2)) is measured for charm (D-0) and strange (K-S(0), Lambda, Xi(-), and Omega(-)) hadrons, using a data sample of p + Pb collisions collected by the CMS experiment, at a nucleonnucleon center-of- mass energy of root(NN)-N-s = 8.16 TeV. A significant positive upsilon(2) signal from long- range azimuthal correlations is observed for all particle species in high- multiplicity p + Pb collisions. The measurement represents the first observation of possible long-range collectivity for open heavy flavor hadrons in small systems. The results suggest that charm quarks have a smaller upsilon(2) than the lighter quarks, probably reflecting a weaker collective behavior. This effect is not seen in the larger PbPb collision system at root(NN)-N-s = 5.02 TeV, also presented.
  • Adam, J.; Brucken, E. J.; Chang, B.; Kim, D. J.; Litichevskyi, V.; Mieskolainen, M. M.; Orava, R.; Rak, J.; Räsänen, S. S.; Snellman, T. W.; Trzaska, W. H.; Viinikainen, J.; The ALICE collaboration (2017)
    Two-particle angular correlations were measured in pp collisions at root s = 7 TeV for pions, kaons, protons, and lambdas, for all particle/anti-particle combinations in the pair. Data for mesons exhibit an expected peak dominated by effects associated with mini-jets and are well reproduced by general purpose Monte Carlo generators. However, for baryon-baryon and anti-baryon-anti-baryon pairs, where both particles have the same baryon number, a near-side anti-correlation structure is observed instead of a peak. This effect is interpreted in the context of baryon production mechanisms in the fragmentation process. It currently presents a challenge to Monte Carlo models and its origin remains an open question.
  • Adam, J.; Brucken, E. J.; Chang, B.; Hilden, T. E.; Kim, D. J.; Kral, J.; Mieskolainen, M. M.; Rak, J.; Rasanen, S. S.; Snellman, T. W.; Trzaska, W. H.; The ALICE collaboration (2015)
    Charged jet production cross sections in p-Pb collisions at root s(NN) = 5.02 TeV measured with the ALICE detector at the LHC are presented. Using the anti-k(T) algorithm, jets have been reconstructed in the central rapidity region from charged particles with resolution parameters R = 0.2 and R = 0.4. The reconstructed jets have been corrected for detector effects and the underlying event background. To calculate the nuclear modification factor, R-pPb, of charged jets in p-Pb collisions, a pp reference was constructed by scaling previously measured charged jet spectra at root s = 7 TeV. In the transverse momentum range 20
  • Adam, J.; Adamova, D.; Aggarwal, M. M.; Rinella, G. Aglieri; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahn, S. U.; Aiola, S.; Akindinov, A.; Alam, S. N.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Almaraz, J. R. M.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Anticic, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshaeuser, H.; Arcelli, S.; Arnaldi, R.; Arnold, O. W.; Arsene, I. C.; Arslandok, M.; Audurier, B.; Augustinus, A.; Averbeck, R.; Brucken, E. J.; Chang, B.; Kim, D. J.; Krizek, F.; Mieskolainen, M. M.; Orava, R.; Rak, J.; Räsänen, S. S.; Snellman, T. W.; Trzaska, W. H. (2016)
    The measurement of prompt D-meson production as a function of multiplicity in p-Pb collisions at TeV with the ALICE detector at root s(NN) the LHC is reported. D-0, D+ and Dau+ mesons are reconstructed via their hadronic decay channels in the centre-of-mass rapidity range -0.96 <y(cms) <0.04 and transverse momentum interval 1 <p(T) <24 GeV/c. The multiplicity dependence of D-meson production is examined by either comparing yields in p-Pb collisions in different event classes, selected based on the multiplicity of produced particles or zero-degree energy, with those in pp collisions, scaled by the number of binary nucleon-nucleon collisions (nuclear modification factor); as well as by evaluating the per-event yields in p-Pb collisions in different multiplicity intervals normalised to the multiplicity-integrated ones (relative yields). The nuclear modification factors for D-0, D+ and D*(+) are consistent with one another. The D-meson nuclear modification factors as a function of the zero-degree energy are consistent with unity within uncertainties in the measured p(T) regions and event classes. The relative D-meson yields, calculated in various p(T) intervals, increase as a function of the charged-particle multiplicity. The results are compared with the equivalent pp measurements at root s = 7 TeV as well as with EPOS 3 calculations.
  • Aidala, C.; Akiba, Y.; Alfred, M.; Andrieux, V.; Aoki, K.; Apadula, N.; Asano, H.; Ayuso, C.; Azmoun, B.; Babintsev, V.; Bandara, N. S.; Barish, K. N.; Bathe, S.; Bazilevsky, A.; Beaumier, M.; Belmont, R.; Berdnikov, A.; Berdnikov, Y.; Blau, D. S.; Boer, M.; Bok, J. S.; Brooks, M. L.; Bryslawskyj, J.; Bumazhnov, V.; Butler, C.; Campbell, S.; Roman, V. Canoa; Cervantes, R.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Citron, Z.; Connors, M.; Cronin, N.; Csanad, M.; Csorgo, T.; Danley, T. W.; Daugherity, M. S.; David, G.; DeBlasio, K.; Dehmelt, K.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dion, A.; Dixit, D.; Do, J. H.; Kim, D. J.; Novitzky, N. (2017)
    We present measurements of long-range angular correlations and the transverse momentum dependence of elliptic flow v(2) in high-multiplicity p + Au collisions at root S-NN = 200 GeV. A comparison of these results to previous measurements in high-multiplicity d + Au and He-3+Au collisions demonstrates a relation between v(2) and the initial collision eccentricity epsilon(2), suggesting that the observed momentum-space azimuthal anisotropies in these small systems have a collective origin and reflect the initial geometry. Good agreement is observed between the measured v(2) and hydrodynamic calculations for all systems, and an argument disfavoring theoretical explanations based on initial momentum-space domain correlations is presented. The set of measurements presented here allows us to leverage the distinct intrinsic geometry of each of these systems to distinguish between different theoretical descriptions of the long-range correlations observed in small collision systems.
  • Abelev, B.; Adam, J.; Adamova, D.; Aggarwal, M. M.; Agnello, M.; Agostinelli, A.; Agrawal, N.; Ahammed, Z.; Ahmad, N.; Ahmed, I.; Ahn, S. U.; Ahn, S. A.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Alam, S. N.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alici, A.; Alkin, A.; Alme, J.; Alta, T.; Altinpinar, S.; Altsybeev, I.; Garcia Prado, C. Alves; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Anticic, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshaeuser, H.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Chang, B.; Hilden, T. E.; Kim, D. J.; Kral, J.; Pohjoisaho, E. H. O.; Rak, J.; Räsänen, S. S.; Trzaska, W. H. (2015)
    Two-particle angular correlations between unidentified charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum range 0.7 <p(T),(assoc) <p(T),(trig) <5.0 GeV/c is examined, to include correlations induced by jets originating from low momentum-transfer scatterings (minijets). The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range vertical bar eta vertical bar <0.9. The near-side long-range pseudorapidity correlations observed in high-multiplicity p-Pb collisions are subtracted from both near-side short-range and away-side correlations in order to remove the non-jet-like components. The yields in the jet-like peaks are found to be invariant with event multiplicity with the exception of events with low multiplicity. This invariance is consistent with the particles being produced via the incoherent fragmentation of multiple parton-parton scatterings, while the yield related to the previously observed ridge structures is not jet-related. The number of uncorrelated sources of particle production is found to increase linearly with multiplicity, suggesting no saturation of the number of multi-parton interactions even in the highest multiplicity p-Pb collisions. Further, the number scales only in the intermediate multiplicity region with the number of binary nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/3.0/).
  • The CMS collaboration; Sirunyan, A. M.; Eerola, P.; Kirschenmann, H.; Pekkanen, J.; Voutilainen, M.; Havukainen, J.; Heikkilä, J. K.; Järvinen, T.; Karimäki, V.; Kinnunen, R.; Lampén, T.; Lassila-Perini, K.; Laurila, S.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Siikonen, H.; Tuominen, E.; Tuominiemi, J.; Tuuva, T. (2019)
    A measurement of the elliptic flow (v(2)) of prompt J/psi mesons in high-multiplicity pPbcollisions is reported using data collected by the CMS experiment at a nucleon-nucleon center-of-mass energy root s(NN)= 8.16 TeV. Prompt J/psi mesons decaying into two muons are reconstructed in the rapidity region in the nucleon-nucleon center-of-mass frame (y(cm)), corresponding to either -2.86 < y(cm) < -1.86 or 0.94 < y(cm)< 1.94. The average v(2) result from the two rapidity ranges is reported over the transverse momentum (p(T)) range from 0.2 to 10 GeV. Positive v(2) values are observed for the prompt J/psi meson, as extracted from long-range two-particle correlations with charged hadrons, for 2 < p(T) < 8 GeV. The prompt J/psi results are compared with previous CMS measurements of elliptic flow for open charm mesons (D-0) and strange hadrons. From these measurements, constraints can be obtained on the collective dynamics of charm quarks produced in high-multiplicity events arising from small systems. (c) 2019 The Author(s). Published by Elsevier B.V.
  • Valoppi, Fabio; Maina, Ndegwa; Allen, Marja; Miglioli, Roberta; Kilpelainen, Petri O.; Mikkonen, Kirsi S. (2019)
    The food industry has a considerable demand for functional foods, such as emulsions as delivery system for omega-6 and omega-3 fatty acids. Such delivery systems must be stabilized, ideally with a compound that fulfills the criteria for both functionality and sustainability. Spruce galactoglucomannans (GGM) are novel, wood-derived, natural, value-added, versatile, multi-purpose emulsifiers that can physically stabilize oil-in-water emulsions while simultaneously protecting the oil phase against oxidation. In this study, we present for the first time the use of GGM-stabilized emulsions as complex multicomponent delivery systems for omega-6 and omega-3 fatty acids, i.e., (1) cod liver oil in drinkable yogurt and (2) oat oil in a gluten-free vegan beverage. The emulsions and the resulting functionalized beverages were characterized in terms of their physical stabilities. In addition, functionalized, drinkable yogurt was characterized in terms of the oxidative stability of the oil. Results highlighted that oil droplets stabilized with GGM were stable during storage, against thermal treatment, upon addition into the beverages, and GGM protected cod liver oil against oxidation in drinkable yogurt. The results reported here highlight the vast potential for the use of wood lignocellulose-derived, multi-functional hydrocolloids in modern foods.