Measurement of an Excess in the Yield of J/ψ at Very Low pT in Pb–Pb Collisions at sNN = 2.76 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

We report on the first measurement of an excess in the yield of J=ψ at very low transverse momentum (pT < 0.3 GeV=c) in peripheral hadronic Pb-Pb collisions at sNN 1⁄4 2.76 TeV, performed by ALICE at the CERN LHC. Remarkably, the measured nuclear modification factor of J=ψ in the rapidity range 2.5 < y < 4 reaches about 7 (2) in the pT range 0–0.3 GeV=c in the 70%–90% (50%–70%) centrality class. The J=ψ production cross section associated with the observed excess is obtained under the hypothesis that coherent photoproduction of J=ψ is the underlying physics mechanism. If confirmed, the observa ...Daha fazlası

Makale 2016 7 Görüntülenme

Direct photon production in Pb-Pb collisions at sNN−−−√ = 2.76 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

Direct photon production at mid-rapidity in Pb-Pb collisions at sNN−−−√=2.76 TeV was studied in the transverse momentum range 0.9

Makale 2016 8 Görüntülenme

Direct photon elliptic flow in Pb–Pb collisions at √sNN = 2.76 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

The elliptic flow of inclusive and direct photons was measured at mid-rapidity in two centrality classes 0–20% and 20–40% in Pb–Pb collisions at √sNN = 2.76 TeV by ALICE. Photons were detected with the highly segmented electromagnetic calorimeter PHOS and via conversions in the detector material with the e+e− pairs reconstructed in the central tracking system. The results of the two methods were combined and the direct-photon elliptic flow was extracted in the transverse momentum range 0.9 < pT < 6.2 GeV/c. A comparison to RHIC data shows a similar magnitude of the measured direct- photon elli ...Daha fazlası

Makale 2019 5 Görüntülenme

p-p, p-lambda, and lambda-lambda correlations studied via femtoscopy in pp reactions at √s = 7 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

We report on the first femtoscopic measurement of baryon pairs, such as p-p, p-, and , measured by ALICE at the Large Hadron Collider (LHC) in proton-proton collisions at √s = 7 TeV. This study demonstrates the feasibility of such measurements in pp collisions at ultrarelativistic energies. The femtoscopy method is employed to constrain the hyperon-nucleon and hyperon-hyperon interactions, which are still rather poorly understood. A new method to evaluate the influence of residual correlations induced by the decays of resonances and experimental impurities is hereby presented. The p-p, p-, and ...Daha fazlası

Makale 2019 3 Görüntülenme

Constraining the magnitude of the Chiral Magnetic Effect with Event Shape Engineering in Pb–Pb collisions at √sNN = 2.76 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

In ultrarelativistic heavy-ion collisions, the event-by-event variation of the fluctuations in the shape of the initial state of the system. This allows to select events with the same centrality but different initial geometry. This selection technique, Event Shape Engineering, has been used in the analysis of charge-dependent two- and three-particle correlations in Pb–Pb collisions at √sNN = 2.76 TeV. The two-particle correlator ⟨cos(φα − φβ )⟩, calculated for different combinations of charges α and β, is almost independent of v2 (for a given centrality), while the three-particle correlator ⟨c ...Daha fazlası

Makale 2017 3 Görüntülenme

One-dimensional pion, kaon, and proton femtoscopy in Pb-Pb collisions at √sNN = 2.76 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

The size of the particle emission region in high-energy collisions can be deduced using the femtoscopic correlations of particle pairs at low relative momentum. Such correlations arise due to quantum statistics and Coulomb and strong final state interactions. In this paper, results are presented from femtoscopic analyses of π±π±, K±K±, KS0KS0, pp, and pp correlations from Pb-Pb collisions at √sNN = 2.76 TeV by the ALICE experiment at the LHC. One-dimensional radii of the system are extracted from correlation functions in terms of the invariant momentum difference of the pair. The comparison of ...Daha fazlası

Makale 2015 5 Görüntülenme

Determination of the event collision time with the ALICE detector at the LHC

KARASU UYSAL, Ayben | ALICE Collaboration

Particle identification is an important feature of the ALICE detector at the LHC. In particular, for particle identification via the time-of-flight technique, the precise determination of the event collision time represents an important ingredient of the quality of the measurement. In this paper, the different methods used for such a measurement in ALICE by means of the T0 and the TOF detectors are reviewed. Efficiencies, resolution and the improvement of the particle identification separation power of the methods used are presented for the different LHC colliding systems (pp, p-Pb and Pb-Pb) ...Daha fazlası

Makale 2017 3 Görüntülenme

Higher harmonic flow coefficients of identified hadrons in Pb-Pb collisions at √sNN = 2.76 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

The elliptic, triangular, quadrangular and pentagonal anisotropic flow coeffi- cients for π±, K± and p+p in Pb-Pb collisions at √sNN = 2.76 TeV were measured with the ALICE detector at the Large Hadron Collider. The results were obtained with the Scalar Product method, correlating the identified hadrons with reference particles from a different pseudorapidity region. Effects not related to the common event symmetry planes (non-flow) were estimated using correlations in pp collisions and were subtracted from the measure- ment. The obtained flow coefficients exhibit a clear mass ordering for tra ...Daha fazlası

Makale 2016 4 Görüntülenme

Production of charged pions, kaons and protons at large transverse momenta in pp and Pb–Pb collisions at 2.76 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

Transverse momentum spectra of π±, K± and p(p ̄) up to pT = 20 GeV/c at mid-rapidity in pp, peripheral (60–80%) and central (0–5%) Pb–Pb collisions at √sNN = 2.76 TeV have been measured using the ALICE detector at the Large Hadron Collider. The proton-to-pion and the kaon-to-pion ratios both show a distinct peak at pT ≈ 3 GeV/c in central Pb–Pb collisions. Below the peak, pT < 3 GeV/c, both ratios are in good agreement with hydrodynamical calculations, suggesting that the peak itself is dominantly the result of radial flow rather than anomalous hadronization processes. For pT > 10 GeV/c partic ...Daha fazlası

Makale 2014 7 Görüntülenme

3ΛH and 3Λ¯ production in Pb–Pb collisions at √sNN = 2.76 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

The production of the hypertriton nuclei 3ΛH and 3Λ¯ has been measured for the first time in Pb–Pb collisions at √sNN = 2.76 TeV with the ALICE experiment at LHC. The pT-integrated 3 !H yield in one unity of rapidity, dN/dy × B.R. ! 3 !H→3He,π−" = (3.86 ± 0.77(stat.) ± 0.68(syst.)) × 10−5 in the 0–10% most central collisions, is consistent with the predictions from a statistical thermal model using the same temperature as for the light hadrons. The coalescence parameter B3 shows a dependence on the transverse momentum, similar to the B2 of deuterons and the B3 of 3He nuclei. The ratio of yield ...Daha fazlası

Makale 2016 8 Görüntülenme

Dielectron measurements in pp and Pb-Pb colllisions with ALICE at the LHC

KARASU UYSAL, Ayben | ALICE Collaboration

The production of low-mass dielectrons is one of the most promising tools for the investigation of chiral symmetry restoration and thermal radiation from the QGP created in heavy-ion collisions. To single out the signal characteristics of the QGP, it is crucial to understand the primordial e+e− pair production in vacuum, i.e. in inelastic proton-proton (pp) collisions. Low-mass dielectrons have been measured with ALICE at the LHC in pp collisions at √s = 7 and 13 TeV, and in Pb–Pb collisions at √sNN = 2.76 TeV. An overview of the results on dielectron production is presented, together with the ...Daha fazlası

Makale 2019 ELSEVIER SCIENCE BV 6 Görüntülenme

Measurement of the inclusive J/ψ polarization at forward rapidity in pp collisions at √s = 8 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

We report on the measurement of the inclusive J/ψ polarization parameters in pp collisions at a center of mass energy √s = 8 TeV with the ALICE detector at the LHC. The analysis is based on a data sample corresponding to an integrated luminosity of 1.23 pb−1. J/ψ resonances are reconstructed in their di-muon decay channel in the rapidity interval 2.5 < y < 4.0 and over the transverse-momentum interval 2 < pT < 15 GeV/c. The three polarization param- eters (λθ , λφ , λθ φ ) are measured as a function of pT both in the helicity and Collins-Soper reference frames. The mea- sured J/ψ polarization ...Daha fazlası

Makale 2018 8 Görüntülenme

Detaylı Arama

Filtreler

Koleksiyon [3]

İlgili Araştırmacılar [1]

Ambargo Durumu [1]

Tam Metin [2]

Yayın Türü [3]

Yazar/lar [3]

Atıf Dizini [3]

Konu Başlıkları [20]

Yayıncı [11]

Yayın Tarihi [10]

Yayın Dili [2]

Measurement of an Excess in the Yield of J/ψ at Very Low pT in Pb–Pb Collisions at sNN = 2.76 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

Direct photon production in Pb-Pb collisions at sNN−−−√ = 2.76 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

Direct photon elliptic flow in Pb–Pb collisions at √sNN = 2.76 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

p-p, p-lambda, and lambda-lambda correlations studied via femtoscopy in pp reactions at √s = 7 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

Constraining the magnitude of the Chiral Magnetic Effect with Event Shape Engineering in Pb–Pb collisions at √sNN = 2.76 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

One-dimensional pion, kaon, and proton femtoscopy in Pb-Pb collisions at √sNN = 2.76 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

Determination of the event collision time with the ALICE detector at the LHC

KARASU UYSAL, Ayben | ALICE Collaboration

Higher harmonic flow coefficients of identified hadrons in Pb-Pb collisions at √sNN = 2.76 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

Production of charged pions, kaons and protons at large transverse momenta in pp and Pb–Pb collisions at 2.76 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

3ΛH and 3Λ¯ production in Pb–Pb collisions at √sNN = 2.76 TeV

KARASU UYSAL, Ayben | ALICE Collaboration

Dielectron measurements in pp and Pb-Pb colllisions with ALICE at the LHC

KARASU UYSAL, Ayben | ALICE Collaboration

Measurement of the inclusive J/ψ polarization at forward rapidity in pp collisions at √s = 8 TeV

KARASU UYSAL, Ayben | ALICE Collaboration