Heavy Hadrons Production by Coalescence Plus Fragmentation in AA Collisions at RHIC and LHC

The hadronization process of heavy hadrons with bottom and charm quarks, especially for baryons Λ c , in a dense QGP medium is largely not understood. We present within a coalescence plus fragmentation model the predictions for D 0 and Λ c spectra and the related baryon to meson ratios at RHIC and LHC. We will discuss how our model can predict values for Λ c / D 0 of the order of O(1), which is much larger than the expectations from fragmentation, and in agreement whit early data from STAR collaboration. Furthermore in the same scheme can be predicted a baryon to meson ratio Λ c / D 0 in pp collisions assuming that at the LHC top energies there can be the formation of QGP matter. The results show a considerable volume effects that significantly reduce the ratios, but still predict quite larger values with respect to fragmentation, in agreement with recent data from ALICE in pp collisions.

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Self-similarity of hadron production in pp and AA collisions at high energies

International Journal of Modern Physics A ◽

10.1142/s0217751x15501274 ◽

2015 ◽

Vol 30 (21) ◽

pp. 1550127 ◽

Cited By ~ 10

Author(s):

D. A. Artemenkov ◽

G. I. Lykasov ◽

A. I. Malakhov

Keyword(s):

Hadron Production ◽

The Self ◽

Pp Collisions ◽

Self Similarity ◽

High Energies ◽

Wide Range ◽

Aa Collisions

We analyze the self-similarity approach applied to study the hadron production in pp and AA collisions. This approach allows us to describe rather well the ratio of the proton to antiproton yields in AA collisions as a function of the energy at a wide range from a few GeV to a few TeV. We suggest a modification of this approach to describe rather well the inclusive spectra of hadrons produced in pp collisions at different initial energies from the AGS to LHC.

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Highlights from the STAR experiment

EPJ Web of Conferences ◽

10.1051/epjconf/201920401018 ◽

2019 ◽

Vol 204 ◽

pp. 01018

Author(s):

Alexey Aparin

Keyword(s):

Beam Energy ◽

Star Collaboration ◽

Fixed Target ◽

Directed Flow ◽

Decay Modes ◽

Charm Quarks ◽

Star Experiment ◽

The One ◽

Beam Energy Scan ◽

Program Show

We present an overview of the recent results obtained by the STAR Collaboration at RHIC.We report the beam energy dependence of directed flow of strange particles. These results support the assumption, that directed flow is formed before hadronization and observed particles are formed via coalescence of constituent quarks. First evidence of a non-zero directed flow of D0 meson is reported. We present the precision measurement of elliptic flow of D0 meson and the first measurement of Λc baryon in Au+Au collisions at $\rad{}{s_{NN} } = 200\,{\rm{GeV}}$, which suggests thermalization of charm quarks. We report results of global Λ polarization measurements in Au+Au collisions, together with the investigation of polarization dependence of centrality and transverse momentum pT. Results from the STAR fixed-target program show good agreement with previously obtained results. A precise measurement of the $_{{\rm{\Lambda }}}^{3} H$ lifetime is presented. Mesonic decay modes are used to reconstruct the $_{{\rm{\Lambda }}}^{3} H$ from Au+Au collisions. The measured lifetime is about 50% shorter than the one of a free Λ, indicating a strong hyperon-nucleon interaction in the hypernucleus system. Finally, we give an outlook to detector upgrades for the Beam Energy Scan phase II.

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Rope Hadronization and Strange Particle Production

EPJ Web of Conferences ◽

10.1051/epjconf/201817114003 ◽

2018 ◽

Vol 171 ◽

pp. 14003 ◽

Cited By ~ 4

Author(s):

Christian Bierlich

Keyword(s):

Particle Production ◽

Strange Particle ◽

High Multiplicity ◽

Future Prospects ◽

Pp Collisions ◽

Small Systems ◽

Strange Hadron ◽

Strange Particle Production ◽

Hadronization Model ◽

Aa Collisions

Rope Hadronization is a model extending the Lund string hadronization model to describe environments with many overlapping strings, such as high multiplicity pp collisions or AA collisions. Including effects of Rope Hadronization drastically improves description of strange/non-strange hadron ratios as function of event multiplicity in all systems from e+e− to AA. Implementation of Rope Hadronization in the MC event generators Dipsy and Pythia8 is discussed, as well as future prospects for jet studies and studies of small systems.

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NATURE OF ANTIPROTON PRODUCTION IN HIGH ENERGY NUCLEAR COLLISIONS: ASSORTED DATA VERSUS SPECIFIC MODELS

International Journal of Modern Physics A ◽

10.1142/s0217751x0200589x ◽

2002 ◽

Vol 17 (08) ◽

pp. 1159-1173 ◽

Cited By ~ 3

Author(s):

P. GUPTAROY ◽

D. P. BHATTACHARYYA ◽

BHASKAR DE ◽

S. BHATTACHARYYA

Keyword(s):

High Energy ◽

Pp Collisions ◽

Nuclear Collisions ◽

Production Processes ◽

Nuclear Interactions ◽

Antiproton Production ◽

Aa Collisions

We attempt here to deal with some of the important characteristics of secondary antiproton production in various high energy nuclear interactions on the basis of a model for production of particles in PP collisions. The results have, thereafter, been converted to those for AA collisions through an appropriate mechanism. The effect of rescattering and cascading in the production processes and on the chosen models has also been incorporated in a phenomenological manner. Comparison of the calculated results with data on the relevant observables leads to a striking agreement and this fair success is claimed here to obviously signal the strength of the basic models that are applied in the present work.

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Hyperon $\Omega$ Production in $pp$ Collisions at Energy 8 TeV

Communications in Physics ◽

10.15625/0868-3166/27/1/9264 ◽

2017 ◽

Vol 27 (1) ◽

pp. 91

Author(s):

Nguyen Thị Dung ◽

Nguyen Mau Chung ◽

Tran Minh Tam

Keyword(s):

Strange Quark ◽

Transport Theory ◽

Pp Collisions ◽

Hyperon Production ◽

Rich Detector ◽

Hadronization Process ◽

The Rich ◽

8 Tev ◽

Daughter Particle ◽

The Ideal

Because strange quark produced copiously in pp collisions, strange hyperon production is one of the ideal tools to investigate the hadronization process and baryon transport theory. We are especially interested in the hyperon Ω production because this baryon contents only strange quark. Our new studies of the pure strange hyperon Ω produced in pp collision at s = 8 TeV are shown in this report. The following strategy is used to reconstruct the strange hyperon Ω. In the LHCb experiment, the hadrons p, π and K are identified by the RICH detector with PT threshold > 100 MeV. Only Lambda (from channel Λ → p + π) with PT > 500 MeV are chosen to combine with kaon daughter particle in order to reconstruct a strange hyperon Ω. The reconstructed particles are accepted as Ω candidates in the case it satisfies several criteria such as its invariance mass must be located within the window mas ± 50 MeV/c2 around the nominal value. More than 63 millions selected events are used for this analysis and about 8100 hyperon Ω candidates are reconstructed.

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Measurement of azimuthal correlations of D mesons with charged particles in pp collisions at √s=13$\sqrt s = 13$ TeV with ALICE at the LHC

EPJ Web of Conferences ◽

10.1051/epjconf/201919904002 ◽

2019 ◽

Vol 199 ◽

pp. 04002

Author(s):

Bharati Naik

Keyword(s):

D Mesons ◽

Hadron Collider ◽

Charged Particles ◽

Gluon Plasma ◽

High Energy ◽

Dense Medium ◽

Pp Collisions ◽

Angular Correlations ◽

Charm Quarks ◽

Azimuthal Correlations

The ALICE (A Large Ion Collider Experiment) detector at the LHC (Large Hadron Collider) is dedicated to the study of the properties of the hot and dense QCD matter (Quark–Gluon Plasma) produced in the nucleus-nucleus collisions at high energy. Heavy quarks (charm and beauty), having large masses, are produced in the hard-parton scattering in the early stages of the collision. Therefore, they experience the whole evolution of the hot and dense medium, representing an important tool for its characterization. The study of angular correlations between D mesons and charged particles in Pb–Pb collisions gives insight about the energy loss of charm quarks and the medium-induced modification of its fragmentation into jets. Moreover, pp collisions help to understand the production mechanisms, fragmentation and hadronization of charm quarks and acts as a reference for p–Pb and Pb–Pb measurements. In this article, the measurement of azimuthal correlations between D0 meson and charged particles in pp collisions at $\sqrt s = 13$ TeV is presented. The collisional energy dependence of the correlations is extracted from the comparison with the results at $\sqrt s = 7$ TeV. The data are also compared with simulations performed with different event generators.

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