The Experts below are selected from a list of 240033 Experts worldwide ranked by ideXlab platform
Timo Otonkoski - One of the best experts on this subject based on the ideXlab platform.
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mechanisms of coxsackievirus b5 mediated β cell death depend on the Multiplicity of infection
Journal of Medical Virology, 2004Co-Authors: Suvi Rasilainen, Risto Lapatto, Merja Roivainen, Petri Ylipaasto, Tapani Hovi, Timo OtonkoskiAbstract:Coxsackievirus infections may trigger and accelerate pancreatic β-cell death, leading to type I diabetes. Unrestricted coxsackievirus B5 replication in cultured β-cells inoculated with high Multiplicity leads to rapid lytic cell death. Evidence from other virus-host cell systems indicates that host cell responses to infection may depend on the Multiplicity of infection (MOI). Thus, the aim of this study was to compare the mechanisms of β-cell death during high versus low Multiplicity of coxsackievirus B5 infection. Cultures of highly differentiated mouse insulinoma cells and primary adult human islets were infected with coxsackievirus B5 at multiplicities of >1,000 or <0.5 TCID50 per cell. The results of nuclear morphology and viability stainings, TUNEL staining and electrophoretic DNA fragmentation analysis showed high Multiplicity infection to predominantly induce necrosis and transient apoptosis. In low Multiplicity culture, however, necrosis was only moderately induced and apoptosis increased steadily with time. This was best demonstrated by a tenfold higher apoptosis/necrosis ratio than after high Multiplicity inoculation. Expression of γ-glutamyl cysteine synthetase increased in both infective cultures but the level of intracellular glutathione permanently depleted only at high Multiplicity and recovered fully at low Multiplicity. Thus, apoptosis represents an important mechanism of β-cell death after low Multiplicity of coxsackievirus B5 infection. This process is associated with maintenance of a physiological intracellular glutathione profile differing dramatically from the high Multiplicity infection during which necrosis dominates and intracellular thiol balance deteriorates. These data suggest that the pattern and mechanisms of coxsackievirus B5 infection induced β-cell death depend on the MOI. J. Med. Virol. 72:586–596, 2004. © 2004 Wiley-Liss, Inc.
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mechanisms of coxsackievirus b5 mediated β cell death depend on the Multiplicity of infection
Journal of Medical Virology, 2004Co-Authors: Suvi Rasilainen, Risto Lapatto, Merja Roivainen, Petri Ylipaasto, Tapani Hovi, Timo OtonkoskiAbstract:Coxsackievirus infections may trigger and accelerate pancreatic β-cell death, leading to type I diabetes. Unrestricted coxsackievirus B5 replication in cultured β-cells inoculated with high Multiplicity leads to rapid lytic cell death. Evidence from other virus-host cell systems indicates that host cell responses to infection may depend on the Multiplicity of infection (MOI). Thus, the aim of this study was to compare the mechanisms of β-cell death during high versus low Multiplicity of coxsackievirus B5 infection. Cultures of highly differentiated mouse insulinoma cells and primary adult human islets were infected with coxsackievirus B5 at multiplicities of >1,000 or <0.5 TCID50 per cell. The results of nuclear morphology and viability stainings, TUNEL staining and electrophoretic DNA fragmentation analysis showed high Multiplicity infection to predominantly induce necrosis and transient apoptosis. In low Multiplicity culture, however, necrosis was only moderately induced and apoptosis increased steadily with time. This was best demonstrated by a tenfold higher apoptosis/necrosis ratio than after high Multiplicity inoculation. Expression of γ-glutamyl cysteine synthetase increased in both infective cultures but the level of intracellular glutathione permanently depleted only at high Multiplicity and recovered fully at low Multiplicity. Thus, apoptosis represents an important mechanism of β-cell death after low Multiplicity of coxsackievirus B5 infection. This process is associated with maintenance of a physiological intracellular glutathione profile differing dramatically from the high Multiplicity infection during which necrosis dominates and intracellular thiol balance deteriorates. These data suggest that the pattern and mechanisms of coxsackievirus B5 infection induced β-cell death depend on the MOI. J. Med. Virol. 72:586–596, 2004. © 2004 Wiley-Liss, Inc.
A M Sirunyan - One of the best experts on this subject based on the ideXlab platform.
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correlations of azimuthal anisotropy fourier harmonics with subevent cumulants in ppb collisions at root s nn 8 16 tev
Physical Review C, 2021Co-Authors: A M Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, Federico Ambrogi, E Asilar, J Brandstetter, Escalante A Del Valle, Martin FlechlAbstract:Event-by-event long-range correlations of azimuthal anisotropy Fourier coefficients (vn) in 8.16 TeV pPb data, collected by the CMS experiment at the CERN Large Hadron Collider, are extracted using a subevent four-particle cumulant technique applied to very low Multiplicity events. Each combination of four charged particles is selected from either two, three, or four distinct subevent regions of a pseudorapidity range from −2.4 to 2.4 of the CMS tracker, and with transverse momentum between 0.3 and 3.0 GeV. Using the subevent cumulant technique, correlations between vn of different orders are measured as functions of particle Multiplicity and compared to the standard cumulant method without subevents over a wide event Multiplicity range. At high multiplicities, the v2 and v3 coefficients exhibit an anticorrelation; this behavior is observed consistently using various methods. The v2 and v4 correlation strength is found to depend on the number of subevents used in the calculation. As the event Multiplicity decreases, the results from different subevent methods diverge because of different contributions of noncollective or few-particle correlations. Correlations extracted with the four-subevent method exhibit a tendency to diminish monotonically toward the lowest Multiplicity region (about 20 charged tracks) investigated. These findings extend previous studies to a significantly lower event Multiplicity range and establish the evidence for the onset of long-range collective multiparticle correlations in small system collisions.
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correlations of azimuthal anisotropy fourier harmonics with subevent cumulants in ppb collisions at snn 8 16 tev
Physical Review C, 2021Co-Authors: A M Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, Federico Ambrogi, E Asilar, J Brandstetter, Escalante A Del Valle, Martin FlechlAbstract:Event-by-event long-range correlations of azimuthal anisotropy Fourier coefficients (vn) in 8.16 TeV pPb data, collected by the CMS experiment at the CERN Large Hadron Collider, are extracted using a subevent four-particle cumulant technique applied to very low Multiplicity events. Each combination of four charged particles is selected from either two, three, or four distinct subevent regions of a pseudorapidity range from −2.4 to 2.4 of the CMS tracker, and with transverse momentum between 0.3 and 3.0 GeV. Using the subevent cumulant technique, correlations between vn of different orders are measured as functions of particle Multiplicity and compared to the standard cumulant method without subevents over a wide event Multiplicity range. At high multiplicities, the v2 and v3 coefficients exhibit an anticorrelation; this behavior is observed consistently using various methods. The v2 and v4 correlation strength is found to depend on the number of subevents used in the calculation. As the event Multiplicity decreases, the results from different subevent methods diverge because of different contributions of noncollective or few-particle correlations. Correlations extracted with the four-subevent method exhibit a tendency to diminish monotonically toward the lowest Multiplicity region (about 20 charged tracks) investigated. These findings extend previous studies to a significantly lower event Multiplicity range and establish the evidence for the onset of long-range collective multiparticle correlations in small system collisions.
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Correlations of azimuthal anisotropy Fourier harmonics with subevent cumulants in pPb collisions at sNN =8.16 TeV
'American Physical Society (APS)', 2021Co-Authors: A M Sirunyan, Tumasyan A., Adam W., Ambrogi F., Asilar E., Bergauer T., Brandstetter J., Dragicevic M., Erö J., Escalante Del Valle, A.Abstract:Event-by-event long-range correlations of azimuthal anisotropy Fourier coefficients (vn) in 8.16 TeV pPb data, collected by the CMS experiment at the CERN Large Hadron Collider, are extracted using a subevent four-particle cumulant technique applied to very low Multiplicity events. Each combination of four charged particles is selected from either two, three, or four distinct subevent regions of a pseudorapidity range from -2.4 to 2.4 of the CMS tracker, and with transverse momentum between 0.3 and 3.0 GeV. Using the subevent cumulant technique, correlations between vn of different orders are measured as functions of particle Multiplicity and compared to the standard cumulant method without subevents over a wide event Multiplicity range. At high multiplicities, the v2 and v3 coefficients exhibit an anticorrelation; this behavior is observed consistently using various methods. The v2 and v4 correlation strength is found to depend on the number of subevents used in the calculation. As the event Multiplicity decreases, the results from different subevent methods diverge because of different contributions of noncollective or few-particle correlations. Correlations extracted with the four-subevent method exhibit a tendency to diminish monotonically toward the lowest Multiplicity region (about 20 charged tracks) investigated. These findings extend previous studies to a significantly lower event Multiplicity range and establish the evidence for the onset of long-range collective multiparticle correlations in small system collisions.STFC (UK); Marie Curie programme and the European Research Council and Horizon 2020 Gran
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observation of correlated azimuthal anisotropy fourier harmonics in pp and p pb collisions at the lhc
Physical Review Letters, 2018Co-Authors: A M Sirunyan, A Tumasyan, T Bergauer, M Dragicevic, Wolfgang Adam, Federico Ambrogi, E Asilar, J Brandstetter, E Brondolin, J EroAbstract:The azimuthal anisotropy Fourier coefficients (v_n) in 8.16 TeV p+Pb data are extracted via long-range two-particle correlations as a function of the event Multiplicity and compared to corresponding results in pp and PbPb collisions. Using a four-particle cumulant technique, v_n correlations are measured for the first time in pp and p+Pb collisions. The v_2 and v_4 coefficients are found to be positively correlated in all collision systems. For high-Multiplicity p+Pb collisions, an anticorrelation of v_2 and v_3 is observed, with a similar correlation strength as in PbPb data at the same Multiplicity. The new correlation results strengthen the case for a common origin of the collectivity seen in p+Pb and PbPb collisions in the measured Multiplicity range.
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observation of long range near side angular correlations in ppb collisions at the lhc
Physics Letters B, 2013Co-Authors: S Chatrchyan, V Khachatryan, A M Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, C Fabjan, E Aguilo, M FriedlAbstract:Results on two-particle angular correlations for charged particles emitted in pPb collisions at a nucleon–nucleon center-of-mass energy of 5.02 TeV are presented. The analysis uses two million collisions collected with the CMS detector at the LHC. The correlations are studied over a broad range of pseudorapidity, η, and full azimuth, φ, as a function of charged particle Multiplicity and particle transverse momentum, p_T. In high-Multiplicity events, a long-range (2 < |Δη| < 4), near-side (Δφ ≈ 0) structure emerges in the two-particle Δη–Δφ correlation functions. This is the first observation of such correlations in proton–nucleus collisions, resembling the ridge-like correlations seen in high Multiplicity pp collisions at √s = 7 TeV and in AA collisions over a broad range of center-of-mass energies. The correlation strength exhibits a pronounced maximum in the range of p_T = 1–1.5 GeV/c and an approximately linear increase with charged particle Multiplicity for high-Multiplicity events. These observations are qualitatively similar to those in pp collisions when selecting the same observed particle Multiplicity, while the overall strength of the correlations is significantly larger in pPb collisions.
Suvi Rasilainen - One of the best experts on this subject based on the ideXlab platform.
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mechanisms of coxsackievirus b5 mediated β cell death depend on the Multiplicity of infection
Journal of Medical Virology, 2004Co-Authors: Suvi Rasilainen, Risto Lapatto, Merja Roivainen, Petri Ylipaasto, Tapani Hovi, Timo OtonkoskiAbstract:Coxsackievirus infections may trigger and accelerate pancreatic β-cell death, leading to type I diabetes. Unrestricted coxsackievirus B5 replication in cultured β-cells inoculated with high Multiplicity leads to rapid lytic cell death. Evidence from other virus-host cell systems indicates that host cell responses to infection may depend on the Multiplicity of infection (MOI). Thus, the aim of this study was to compare the mechanisms of β-cell death during high versus low Multiplicity of coxsackievirus B5 infection. Cultures of highly differentiated mouse insulinoma cells and primary adult human islets were infected with coxsackievirus B5 at multiplicities of >1,000 or <0.5 TCID50 per cell. The results of nuclear morphology and viability stainings, TUNEL staining and electrophoretic DNA fragmentation analysis showed high Multiplicity infection to predominantly induce necrosis and transient apoptosis. In low Multiplicity culture, however, necrosis was only moderately induced and apoptosis increased steadily with time. This was best demonstrated by a tenfold higher apoptosis/necrosis ratio than after high Multiplicity inoculation. Expression of γ-glutamyl cysteine synthetase increased in both infective cultures but the level of intracellular glutathione permanently depleted only at high Multiplicity and recovered fully at low Multiplicity. Thus, apoptosis represents an important mechanism of β-cell death after low Multiplicity of coxsackievirus B5 infection. This process is associated with maintenance of a physiological intracellular glutathione profile differing dramatically from the high Multiplicity infection during which necrosis dominates and intracellular thiol balance deteriorates. These data suggest that the pattern and mechanisms of coxsackievirus B5 infection induced β-cell death depend on the MOI. J. Med. Virol. 72:586–596, 2004. © 2004 Wiley-Liss, Inc.
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mechanisms of coxsackievirus b5 mediated β cell death depend on the Multiplicity of infection
Journal of Medical Virology, 2004Co-Authors: Suvi Rasilainen, Risto Lapatto, Merja Roivainen, Petri Ylipaasto, Tapani Hovi, Timo OtonkoskiAbstract:Coxsackievirus infections may trigger and accelerate pancreatic β-cell death, leading to type I diabetes. Unrestricted coxsackievirus B5 replication in cultured β-cells inoculated with high Multiplicity leads to rapid lytic cell death. Evidence from other virus-host cell systems indicates that host cell responses to infection may depend on the Multiplicity of infection (MOI). Thus, the aim of this study was to compare the mechanisms of β-cell death during high versus low Multiplicity of coxsackievirus B5 infection. Cultures of highly differentiated mouse insulinoma cells and primary adult human islets were infected with coxsackievirus B5 at multiplicities of >1,000 or <0.5 TCID50 per cell. The results of nuclear morphology and viability stainings, TUNEL staining and electrophoretic DNA fragmentation analysis showed high Multiplicity infection to predominantly induce necrosis and transient apoptosis. In low Multiplicity culture, however, necrosis was only moderately induced and apoptosis increased steadily with time. This was best demonstrated by a tenfold higher apoptosis/necrosis ratio than after high Multiplicity inoculation. Expression of γ-glutamyl cysteine synthetase increased in both infective cultures but the level of intracellular glutathione permanently depleted only at high Multiplicity and recovered fully at low Multiplicity. Thus, apoptosis represents an important mechanism of β-cell death after low Multiplicity of coxsackievirus B5 infection. This process is associated with maintenance of a physiological intracellular glutathione profile differing dramatically from the high Multiplicity infection during which necrosis dominates and intracellular thiol balance deteriorates. These data suggest that the pattern and mechanisms of coxsackievirus B5 infection induced β-cell death depend on the MOI. J. Med. Virol. 72:586–596, 2004. © 2004 Wiley-Liss, Inc.
A Tumasyan - One of the best experts on this subject based on the ideXlab platform.
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correlations of azimuthal anisotropy fourier harmonics with subevent cumulants in ppb collisions at root s nn 8 16 tev
Physical Review C, 2021Co-Authors: A M Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, Federico Ambrogi, E Asilar, J Brandstetter, Escalante A Del Valle, Martin FlechlAbstract:Event-by-event long-range correlations of azimuthal anisotropy Fourier coefficients (vn) in 8.16 TeV pPb data, collected by the CMS experiment at the CERN Large Hadron Collider, are extracted using a subevent four-particle cumulant technique applied to very low Multiplicity events. Each combination of four charged particles is selected from either two, three, or four distinct subevent regions of a pseudorapidity range from −2.4 to 2.4 of the CMS tracker, and with transverse momentum between 0.3 and 3.0 GeV. Using the subevent cumulant technique, correlations between vn of different orders are measured as functions of particle Multiplicity and compared to the standard cumulant method without subevents over a wide event Multiplicity range. At high multiplicities, the v2 and v3 coefficients exhibit an anticorrelation; this behavior is observed consistently using various methods. The v2 and v4 correlation strength is found to depend on the number of subevents used in the calculation. As the event Multiplicity decreases, the results from different subevent methods diverge because of different contributions of noncollective or few-particle correlations. Correlations extracted with the four-subevent method exhibit a tendency to diminish monotonically toward the lowest Multiplicity region (about 20 charged tracks) investigated. These findings extend previous studies to a significantly lower event Multiplicity range and establish the evidence for the onset of long-range collective multiparticle correlations in small system collisions.
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correlations of azimuthal anisotropy fourier harmonics with subevent cumulants in ppb collisions at snn 8 16 tev
Physical Review C, 2021Co-Authors: A M Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, Federico Ambrogi, E Asilar, J Brandstetter, Escalante A Del Valle, Martin FlechlAbstract:Event-by-event long-range correlations of azimuthal anisotropy Fourier coefficients (vn) in 8.16 TeV pPb data, collected by the CMS experiment at the CERN Large Hadron Collider, are extracted using a subevent four-particle cumulant technique applied to very low Multiplicity events. Each combination of four charged particles is selected from either two, three, or four distinct subevent regions of a pseudorapidity range from −2.4 to 2.4 of the CMS tracker, and with transverse momentum between 0.3 and 3.0 GeV. Using the subevent cumulant technique, correlations between vn of different orders are measured as functions of particle Multiplicity and compared to the standard cumulant method without subevents over a wide event Multiplicity range. At high multiplicities, the v2 and v3 coefficients exhibit an anticorrelation; this behavior is observed consistently using various methods. The v2 and v4 correlation strength is found to depend on the number of subevents used in the calculation. As the event Multiplicity decreases, the results from different subevent methods diverge because of different contributions of noncollective or few-particle correlations. Correlations extracted with the four-subevent method exhibit a tendency to diminish monotonically toward the lowest Multiplicity region (about 20 charged tracks) investigated. These findings extend previous studies to a significantly lower event Multiplicity range and establish the evidence for the onset of long-range collective multiparticle correlations in small system collisions.
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observation of correlated azimuthal anisotropy fourier harmonics in pp and p pb collisions at the lhc
Physical Review Letters, 2018Co-Authors: A M Sirunyan, A Tumasyan, T Bergauer, M Dragicevic, Wolfgang Adam, Federico Ambrogi, E Asilar, J Brandstetter, E Brondolin, J EroAbstract:The azimuthal anisotropy Fourier coefficients (v_n) in 8.16 TeV p+Pb data are extracted via long-range two-particle correlations as a function of the event Multiplicity and compared to corresponding results in pp and PbPb collisions. Using a four-particle cumulant technique, v_n correlations are measured for the first time in pp and p+Pb collisions. The v_2 and v_4 coefficients are found to be positively correlated in all collision systems. For high-Multiplicity p+Pb collisions, an anticorrelation of v_2 and v_3 is observed, with a similar correlation strength as in PbPb data at the same Multiplicity. The new correlation results strengthen the case for a common origin of the collectivity seen in p+Pb and PbPb collisions in the measured Multiplicity range.
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observation of long range near side angular correlations in ppb collisions at the lhc
Physics Letters B, 2013Co-Authors: S Chatrchyan, V Khachatryan, A M Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, C Fabjan, E Aguilo, M FriedlAbstract:Results on two-particle angular correlations for charged particles emitted in pPb collisions at a nucleon–nucleon center-of-mass energy of 5.02 TeV are presented. The analysis uses two million collisions collected with the CMS detector at the LHC. The correlations are studied over a broad range of pseudorapidity, η, and full azimuth, φ, as a function of charged particle Multiplicity and particle transverse momentum, p_T. In high-Multiplicity events, a long-range (2 < |Δη| < 4), near-side (Δφ ≈ 0) structure emerges in the two-particle Δη–Δφ correlation functions. This is the first observation of such correlations in proton–nucleus collisions, resembling the ridge-like correlations seen in high Multiplicity pp collisions at √s = 7 TeV and in AA collisions over a broad range of center-of-mass energies. The correlation strength exhibits a pronounced maximum in the range of p_T = 1–1.5 GeV/c and an approximately linear increase with charged particle Multiplicity for high-Multiplicity events. These observations are qualitatively similar to those in pp collisions when selecting the same observed particle Multiplicity, while the overall strength of the correlations is significantly larger in pPb collisions.
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charged particle multiplicities in pp interactions at sqrt s 0 9 2 36 and 7 tev
Journal of High Energy Physics, 2011Co-Authors: V Khachatryan, A M Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, J Ero, C Fabjan, M Friedl, R FruhwirthAbstract:Measurements of primary charged hadron Multiplicity distributions are presented for non-single-diffractive events in proton-proton collisions at centre-of-mass energies of sqrt(s) = 0.9, 2.36, and 7 TeV, in five pseudorapidity ranges from |eta|<0.5 to |eta|<2.4. The data were collected with the minimum-bias trigger of the CMS experiment during the LHC commissioning runs in 2009 and the 7 TeV run in 2010. The Multiplicity distribution at sqrt(s) = 0.9 TeV is in agreement with previous measurements. At higher energies the increase of the mean Multiplicity with sqrt(s) is underestimated by most event generators. The average transverse momentum as a function of the Multiplicity is also presented. The measurement of higher-order moments of the Multiplicity distribution confirms the violation of Koba-Nielsen-Olesen scaling that has been observed at lower energies.
M Dragicevic - One of the best experts on this subject based on the ideXlab platform.
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correlations of azimuthal anisotropy fourier harmonics with subevent cumulants in ppb collisions at root s nn 8 16 tev
Physical Review C, 2021Co-Authors: A M Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, Federico Ambrogi, E Asilar, J Brandstetter, Escalante A Del Valle, Martin FlechlAbstract:Event-by-event long-range correlations of azimuthal anisotropy Fourier coefficients (vn) in 8.16 TeV pPb data, collected by the CMS experiment at the CERN Large Hadron Collider, are extracted using a subevent four-particle cumulant technique applied to very low Multiplicity events. Each combination of four charged particles is selected from either two, three, or four distinct subevent regions of a pseudorapidity range from −2.4 to 2.4 of the CMS tracker, and with transverse momentum between 0.3 and 3.0 GeV. Using the subevent cumulant technique, correlations between vn of different orders are measured as functions of particle Multiplicity and compared to the standard cumulant method without subevents over a wide event Multiplicity range. At high multiplicities, the v2 and v3 coefficients exhibit an anticorrelation; this behavior is observed consistently using various methods. The v2 and v4 correlation strength is found to depend on the number of subevents used in the calculation. As the event Multiplicity decreases, the results from different subevent methods diverge because of different contributions of noncollective or few-particle correlations. Correlations extracted with the four-subevent method exhibit a tendency to diminish monotonically toward the lowest Multiplicity region (about 20 charged tracks) investigated. These findings extend previous studies to a significantly lower event Multiplicity range and establish the evidence for the onset of long-range collective multiparticle correlations in small system collisions.
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correlations of azimuthal anisotropy fourier harmonics with subevent cumulants in ppb collisions at snn 8 16 tev
Physical Review C, 2021Co-Authors: A M Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, Federico Ambrogi, E Asilar, J Brandstetter, Escalante A Del Valle, Martin FlechlAbstract:Event-by-event long-range correlations of azimuthal anisotropy Fourier coefficients (vn) in 8.16 TeV pPb data, collected by the CMS experiment at the CERN Large Hadron Collider, are extracted using a subevent four-particle cumulant technique applied to very low Multiplicity events. Each combination of four charged particles is selected from either two, three, or four distinct subevent regions of a pseudorapidity range from −2.4 to 2.4 of the CMS tracker, and with transverse momentum between 0.3 and 3.0 GeV. Using the subevent cumulant technique, correlations between vn of different orders are measured as functions of particle Multiplicity and compared to the standard cumulant method without subevents over a wide event Multiplicity range. At high multiplicities, the v2 and v3 coefficients exhibit an anticorrelation; this behavior is observed consistently using various methods. The v2 and v4 correlation strength is found to depend on the number of subevents used in the calculation. As the event Multiplicity decreases, the results from different subevent methods diverge because of different contributions of noncollective or few-particle correlations. Correlations extracted with the four-subevent method exhibit a tendency to diminish monotonically toward the lowest Multiplicity region (about 20 charged tracks) investigated. These findings extend previous studies to a significantly lower event Multiplicity range and establish the evidence for the onset of long-range collective multiparticle correlations in small system collisions.
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observation of correlated azimuthal anisotropy fourier harmonics in pp and p pb collisions at the lhc
Physical Review Letters, 2018Co-Authors: A M Sirunyan, A Tumasyan, T Bergauer, M Dragicevic, Wolfgang Adam, Federico Ambrogi, E Asilar, J Brandstetter, E Brondolin, J EroAbstract:The azimuthal anisotropy Fourier coefficients (v_n) in 8.16 TeV p+Pb data are extracted via long-range two-particle correlations as a function of the event Multiplicity and compared to corresponding results in pp and PbPb collisions. Using a four-particle cumulant technique, v_n correlations are measured for the first time in pp and p+Pb collisions. The v_2 and v_4 coefficients are found to be positively correlated in all collision systems. For high-Multiplicity p+Pb collisions, an anticorrelation of v_2 and v_3 is observed, with a similar correlation strength as in PbPb data at the same Multiplicity. The new correlation results strengthen the case for a common origin of the collectivity seen in p+Pb and PbPb collisions in the measured Multiplicity range.
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observation of long range near side angular correlations in ppb collisions at the lhc
Physics Letters B, 2013Co-Authors: S Chatrchyan, V Khachatryan, A M Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, C Fabjan, E Aguilo, M FriedlAbstract:Results on two-particle angular correlations for charged particles emitted in pPb collisions at a nucleon–nucleon center-of-mass energy of 5.02 TeV are presented. The analysis uses two million collisions collected with the CMS detector at the LHC. The correlations are studied over a broad range of pseudorapidity, η, and full azimuth, φ, as a function of charged particle Multiplicity and particle transverse momentum, p_T. In high-Multiplicity events, a long-range (2 < |Δη| < 4), near-side (Δφ ≈ 0) structure emerges in the two-particle Δη–Δφ correlation functions. This is the first observation of such correlations in proton–nucleus collisions, resembling the ridge-like correlations seen in high Multiplicity pp collisions at √s = 7 TeV and in AA collisions over a broad range of center-of-mass energies. The correlation strength exhibits a pronounced maximum in the range of p_T = 1–1.5 GeV/c and an approximately linear increase with charged particle Multiplicity for high-Multiplicity events. These observations are qualitatively similar to those in pp collisions when selecting the same observed particle Multiplicity, while the overall strength of the correlations is significantly larger in pPb collisions.
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charged particle multiplicities in pp interactions at sqrt s 0 9 2 36 and 7 tev
Journal of High Energy Physics, 2011Co-Authors: V Khachatryan, A M Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, J Ero, C Fabjan, M Friedl, R FruhwirthAbstract:Measurements of primary charged hadron Multiplicity distributions are presented for non-single-diffractive events in proton-proton collisions at centre-of-mass energies of sqrt(s) = 0.9, 2.36, and 7 TeV, in five pseudorapidity ranges from |eta|<0.5 to |eta|<2.4. The data were collected with the minimum-bias trigger of the CMS experiment during the LHC commissioning runs in 2009 and the 7 TeV run in 2010. The Multiplicity distribution at sqrt(s) = 0.9 TeV is in agreement with previous measurements. At higher energies the increase of the mean Multiplicity with sqrt(s) is underestimated by most event generators. The average transverse momentum as a function of the Multiplicity is also presented. The measurement of higher-order moments of the Multiplicity distribution confirms the violation of Koba-Nielsen-Olesen scaling that has been observed at lower energies.
