Measurements of Charged-particle Transverse Momentum Spectra in PbPb Collisions at [square Root Of]nn

Measurements of Charged-particle Transverse Momentum Spectra in PbPb Collisions at [square Root Of]nn PDF Author: Eric Appelt
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ISBN:
Category : Collisions (Nuclear physics)
Languages : en
Pages : 148

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Measurements of Charged-particle Transverse Momentum Spectra in PbPb Collisions at [square Root Of]nn

Measurements of Charged-particle Transverse Momentum Spectra in PbPb Collisions at [square Root Of]nn PDF Author: Eric Appelt
Publisher:
ISBN:
Category : Collisions (Nuclear physics)
Languages : en
Pages : 148

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Book Description


Charged Particle Transverse Momentum Spectra in Pp Collisions at Sqrt(s)

Charged Particle Transverse Momentum Spectra in Pp Collisions at Sqrt(s) PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 36

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Book Description
The charged particle transverse momentum (pT) spectra are presented for pp collisions at sqrt(s)=0.9 and 7 TeV. The data samples were collected with the CMS detector at the LHC and correspond to integrated luminosities of 231 inverse microbarns and 2.96 inverse picobarns, respectively. Calorimeter-based high-transverse-energy triggers are employed to enhance the statistical reach of the high-pT measurements. The results are compared with both leading-order QCD and with an empirical scaling of measurements at different collision energies using the scaling variable xT = 2 pT/sqrt(s) over the pT range up to 200 GeV/c. Using a combination of xT scaling and direct interpolation at fixed pT, a reference transverse momentum spectrum at sqrt(s)=2.76 TeV is constructed, which can be used for studying high-pT particle suppression in the dense QCD medium produced in heavy-ion collisions at that centre-of-mass energy.

Measurement of Charged-particle Spectra in Pb+Pb Collisions at \(\sqrt{s_{\mathrm{NN}}}

Measurement of Charged-particle Spectra in Pb+Pb Collisions at \(\sqrt{s_{\mathrm{NN}}} PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Charged-particle spectra obtained in Pb+Pb interactions at \(\sqrt{s_{\mathrm{NN}}}=2.76 \) TeV and pp interactions at \(\sqrt{s_{\mathrm{NN}}}=2.76 \) TeV with the ATLAS detector at the LHC are presented, using data with integrated luminosities of 0.15 nb−1 and 4.2 pb−1, respectively, in a wide transverse momentum (0.5

Study of High Transverse Momentum Charged Particle Suppression in Heavy Ion Collisions at LHC

Study of High Transverse Momentum Charged Particle Suppression in Heavy Ion Collisions at LHC PDF Author: Andre Sungho Yoon
Publisher:
ISBN:
Category :
Languages : en
Pages : 284

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The charged particle spectrum at large transverse momentum (PT), dominated by hadrons originating from parton fragmentation, is an important observable for studying the properties of the hot, dense medium produced in high-energy heavy-ion collisions. The study of the modifications of the PT spectrum in PbPb compared to pp collisions at the same collision energy can shed light on the detailed mechanism by which hard partons lose energy traversing the medium. In this thesis, the transverse momentum spectra of charged particles in pp and PbPb collisions at [square root of]Snn = 2.76 TeV measured up to PT = 100 GeV/c with the CMS experiment at the Large Hadron Collider (LHC) are presented. In the transverse momentum range PT = 5-10 GeV/c, the charged particle yield in the most central PbPb collisions is suppressed by up to a factor of 7 compared to the pp yield scaled by the number of incoherent nucleon-nucleon collisions. At higher PT, this suppression is significantly reduced, approaching roughly a factor of 2 for particles with PT in the range PT = 40-100 GeV/c. A simple modeling of the parton energy loss applied to the PYTHIA Monte-Carlo (MC) reveals that the charged particle spectrum with the pQCD-motivated fractional parton energy loss can describes the shape of the measured suppression well in the range PT = 5-100 GeV/c.

Nuclear Effects on the Transverse Momentum Spectra of Charged Particles in PPb Collisions at $\sqrt{s_{_\mathrm {NN}}}

Nuclear Effects on the Transverse Momentum Spectra of Charged Particles in PPb Collisions at $\sqrt{s_{_\mathrm {NN}}} PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 37

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Book Description
Transverse momentum spectra of charged particles are measured by the CMS experiment at the CERN LHC in pPb collisions at [arrow]"NN = 5.02 TeV, in the range 0.4

Particle Ratios at High Transverse Momentum in Pp Collisions At. Sqrt. S

Particle Ratios at High Transverse Momentum in Pp Collisions At. Sqrt. S PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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The production of identified charged particles in pp collisions at .sqrt.s = 63 GeV with an identified high p/sub T/ trigger particle emitted in the central region is studied. The measurements were performed at the CERN ISR using the Axial Field Spectrometer. Trigger particle ratios, sigma(.pi./sup + -/)/ sigma(all/sup + -/), sigma(K/sup + -/) and sigma(p/sup + -/)/sigma(all/sup + -/) are presented for p/sub T/ from 5 GeV/c to 8 GeV/c. In addition sigma(.pi./sup + -/)/sigma(all/sup + -/) is presented in the p/sub T/ region from 2.5 GeV/c to 4.5 GeV/c. The charge compensation in the hemisphere containing the trigger particle is shown to depend strongly on the identity of the trigger particle and on the identity of the associated particles. 13 references.

Measurement of Charged-particle Spectra in Pb+Pb Collisions at [arrow]"NN

Measurement of Charged-particle Spectra in Pb+Pb Collisions at [arrow] Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 51

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Book Description
Charged-particle spectra obtained in Pb+Pb interactions at [arrow]"NN = 2.76 TeV and pp interactions at [arrow]"NN = 2.76 TeV with the ATLAS detector at the LHC are presented, using data with integrated luminosities of 0.15 nb-1 and 4.2 pb-1, respectively, in a wide transverse momentum (0.5

Study of Parton Energy Loss in Heavy Ion Collisions Using Charged Particle Spectra Measured with CMS

Study of Parton Energy Loss in Heavy Ion Collisions Using Charged Particle Spectra Measured with CMS PDF Author: Austin A. Baty
Publisher:
ISBN:
Category :
Languages : en
Pages : 245

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Book Description
The phenomenology of the strong nuclear force is still not well understood at low momentum transfers and requires experimental input to constrain. Collisions of heavy ions at the Large Hadron Collider provide a unique opportunity to explore this kinematic region because they create a novel form of matter: the quark-gluon plasma (QGP). Using the CMS detector, spectra of charged particles originating from protonproton (pp), proton-lead (pPb), and lead-lead (PbPb) collisions at a center of mass energy per nucleon pair ( [square root of SNN) of 5.02 TeV are examined as a function of transverse momentum and centrality. Nuclear modification factors and fragmentation functions are constructed from these spectra. By comparing to pp collision reference spectra, a puzzle concerning previous measurements in pPb collisions is clarified. A strong suppression of particle production observed in PbPb collisions is also quantified. Finally, collisions of xenon nuclei are also studied to constrain the path length dependence of parton energy loss. The strength of energy loss is found to increase with both [square root of SNN and the average path length through the QGP. Comparisons to theoretical models and previous measurements indicate that the path length dependence is between linear and quadratic, as expected from a combination of collisional and radiative energy loss mechanisms.

Transverse Momentum Spectra and Cross Sections of Charged Particles in Pp Collisions Measured with ALICE

Transverse Momentum Spectra and Cross Sections of Charged Particles in Pp Collisions Measured with ALICE PDF Author: Edgar Pérez Lezama
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Measurement of Transverse Momentum Relative to Dijet Systems in PbPb and $pp$ Collisions at $\sqrt{s_{NN}}

Measurement of Transverse Momentum Relative to Dijet Systems in PbPb and $pp$ Collisions at $\sqrt{s_{NN}} PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 48

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Book Description
An analysis of dijet events in PbPb and pp collisions is performed to explore the properties of energy loss by partons traveling in a quark-gluon plasma. Data are collected at a nucleon-nucleon center-of-mass energy of 2.76 TeV at the LHC. The distribution of transverse momentum (pT) surrounding dijet systems is measured by selecting charged particles in different ranges of pT and at different angular cones of pseudorapidity and azimuth. The measurement is performed as a function of centrality of the PbPb collisions, the pT asymmetry of the jets in the dijet pair, and the distance parameter R used in the anti-kT jet clustering algorithm. In events with unbalanced dijets, PbPb collisions show an enhanced multiplicity in the hemisphere of the subleading jet, with the pT imbalance compensated by an excess of low-pT particles at large angles from the jet axes.