First Measurement of Λ_{c} Baryon Production in Au+Au Collisions at sqrt[s_{NN}]=200  GeV.

We report on the first measurement of the charmed baryon Λ_{c}^{±} production at midrapidity (|y|<1) in Au+Au collisions at sqrt[s_{NN}]=200  GeV collected by the STAR experiment at the Relativistic Heavy Ion Collider. The Λ_{c}/D^{0} [denoting (Λ_{c}^{+}+Λ_{c}^{-})/(D^{0}+D[over ¯]^{0})] yield ratio is measured to be 1.08±0.16  (stat)±0.26  (sys) in the 0%-20% most central Au+Au collisions for the transverse momentum (p_{T}) range 3<p_{T}<6  GeV/c. This is significantly larger than the pythia model calculations for p+p collisions. The measured Λ_{c}/D^{0} ratio, as a function of p_{T} and collision centrality, is comparable to the baryon-to-meson ratios for light and strange hadrons in Au+Au collisions. Model calculations including coalescence hadronization for charmed baryon and meson formation reproduce the features of our measured Λ_{c}/D^{0} ratio.

G. S. Averichev | Y. Wang | J. Thomas | T. Liu | S. Oh | R. Pak | Z. Zhang | L. Pinsky | J. Sandweiss | S. Sato | L. Adamczyk | S. Fazio | P. Federič | A. Gibson | J. Jia | S. Kabana | M. Przybycien | Z. Yang | G. Wang | Z. Zhang | J. Singh | X. Liu | H. Spinka | D. Isenhower | S. Radhakrishnan | Z. Chen | I. Chakaberia | F. Geurts | S. Salur | O. Evdokimov | J. Roberts | Z. Ye | K. Yip | J. Chen | B. Pawlik | D. Underwood | M. Shao | B. Stringfellow | Y. Hu | J. Zhao | Y. Yang | J. Lauret | M. Csanád | H. Ritter | Y. Liu | I. Deppner | N. Herrmann | Y. Leung | Z. Ahammed | R. Bellwied | L. Bland | A. Brandin | H. Caines | D. Cebra | M. Cherney | W. Christie | H. Crawford | A. Derevschikov | L. Didenko | J. Dunlop | J. Engelage | G. Eppley | E. Finch | Y. Fisyak | J. Harris | T. Humanic | G. Igo | W. Jacobs | E. Judd | D. Keane | A. Kisiel | P. Kravtsov | K. Krueger | J. Landgraf | A. Lebedev | R. Lednický | M. Lisa | T. Ljubičić | W. Llope | R. Longacre | R. Majka | S. Margetis | H. Matis | N. Minaev | L. Nogach | G. Odyniec | A. Ogawa | V. Okorokov | Y. Panebratsev | J. Pluta | J. Porter | R. Ray | J. Romero | N. Schmitz | J. Seger | P. Seyboth | E. Shahaliev | B. Srivastava | M. Strikhanov | A. Suaide | M. Šumbera | A. Tang | S. Trentalange | M. Tokarev | O. Tsai | T. Ullrich | A. Vasiliev | S. Voloshin | F. Wang | G. Westfall | H. Wieman | S. Wissink | R. Witt | N. Xu | Z. Xu | P. Shanmuganathan | Y. Liang | W. Xie | C. Markert | X. Chen | Y. Sun | B. Mohanty | Z. Wang | Sirshendu Chatterjee | J. Cheng | X. Zhu | N. Smirnov | J. Webb | H. Qiu | N. Sahoo | M. Nagy | M. Calderón de la Barca Sánchez | D. Anderson | Y. Feng | T. Huang | M. Kelsey | P. Huo | C. Zhou | Z. Zhu | S. Choudhury | J. Adams | R. Kunnawalkam Elayavalli | A. Behera | W. Schmidke | A. Bhasin | J. Bielčík | J. Bielčíková | I. Kisel | L. Kumar | Z. Moravcova | H. Pei | Q. Shou | A. Timmins | H. Zbroszczyk | D. Kikola | I. Vassiliev | M. Aggarwal | D. Tlustý | X. Zhang | Y. Li | J. Putschke | R. Ma | C. Jena | P. Tribedy | S. Esumi | J. Adam | S. Yang | J. Mazer | K. Nayak | R. Reed | S. Singha | M. Zyzak | A. Francisco | J. K. Adkins | G. Agakishiev | I. Alekseev | A. Aparin | E. Aschenauer | M. U. Ashraf | F. Atetalla | A. Attri | V. Bairathi | K. Barish | I. Bordyuzhin | J. Brandenburg | J. Butterworth | P. Chaloupka | B. Chan | F. Chang | Z. Chang | N. Chankova-Bunzarova | D. Chen | M. Chevalier | M. Daugherity | T. Dedovich | X. Dong | J. Drachenberg | T. Edmonds | N. Elsey | R. Esha | J. Ewigleben | O. Eyser | R. Fatémi | J. Fedorišin | C. Feng | P. Filip | L. Fulek | C. Gagliardi | T. Galatyuk | K. Gopal | D. Grosnick | W. Guryn | A. Hamad | Ahmed M. Hamed | W. He | X. He | S. Heppelmann | E. Hoffman | L. Holub | Y. Hong | S. Horvat | X. Huang | A. Jentsch | K. Jiang | S. Jowzaee | X. Ju | M. L. Kabir | S. Kagamaster | D. Kalinkin | K. Kang | D. Kapukchyan | K. Kauder | H. Ke | A. Kechechyan | Y. Khyzhniak | B. Kimelman | D. Kincses | T. Kinghorn | A. Kiselev | M. Kocan | L. Kochenda | L. Kosarzewski | L. Kramárik | J. Kwasizur | R. Lacey | S. Lan | J. Lee | C. Li | W. Li | X. Li | R. Licenik | T. Lin | Y. Lin | F. Liu | H. Liu | P. Liu | Z. Liu | N. Lukow | S. Luo | L. Ma | Y. Ma | N. Magdy | S. Mioduszewski | I. Mooney | D. Morozov | J. Nam | M. Nasim | D. Neff | D. Nemes | M. Nie | G. Nigmatkulov | T. Niida | T. Nonaka | B. Page | A. Pandav | D. Pawłowska | C. Perkins | M. Posik | N. Pruthi | A. Quintero | S. Ramachandran | O. Rogachevskiy | L. Ruan | J. Rusnak | H. Sako | B. Schweid | F. Seck | M. Sergeeva | R. Seto | N. Shah | F. Shen | W. Shen | S. Shi | E. Sichtermann | R. Sikora | M. Simko | W. Solyst | P. Sorensen | T. Stanislaus | M. Stefaniak | D. Stewart | B. Summa | X. Sun | B. Surrow | D. Svirida | P. Szymanski | Z. Tang | A. Taranenko | T. Tarnowsky | C. Tomkiel | R. Tribble | S. Tripathy | Z. Tu | I. Upsal | J. Vanek | S. Vokál | J. Wang | P. Wang | P. Weidenkaff | L. Wen | Y. Wu | Z. Xiao | G. Xie | H. Xu | Y. Xu | C. Yang | Q. Yang | L. Yi | W. Zha | S. Zhang | Y. Zhang | C. Zhong | M. Zurek | G. Ma | G. Van Buren | D. Mallick | R. L. Pinter | F. Videbæk | Y. Ji | S. Huang | N. Kulathunga Mudiyanselage | H. Huang | Q. Xu | D. Zhang | J. Nelson | X. Luo | C. Kim | D. Kikoła | J. Bielcik | T. Liu | X. Luo | C. Yang | M. Calderon De La Barca Sanchez | T. Huang | T. Huang | X. Luo | T. Huang | P. Federic

[1]  S. H. Lee,et al.  Charmed hadron production in an improved quark coalescence model , 2019, Physical Review C.

[2]  M. He,et al.  Hadronization and Charm-Hadron Ratios in Heavy-Ion Collisions. , 2019, Physical review letters.

[3]  G. S. Averichev,et al.  Centrality and transverse momentum dependence of D0 -meson production at mid-rapidity in Au + Au collisions at sNN=200 GeV , 2018, Physical Review C.

[4]  D. F. Lodato,et al.  $\Lambda_\mathrm{c}^+$ production in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV , 2018 .

[5]  T. Stezelberger,et al.  The STAR MAPS-based PiXeL detector , 2017, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.

[6]  V. M. Ghete,et al.  Nuclear modification factor of D0 mesons in PbPb collisions at sNN=5.02TeV , 2017, Physics Letters B.

[7]  V. Greco,et al.  Charmed hadrons from coalescence plus fragmentation in relativistic nucleus-nucleus collisions at RHIC and LHC , 2018, The European Physical Journal C.

[8]  M. Lisovyi,et al.  Combined analysis of charm-quark fragmentation-fraction measurements , 2015, 1509.01061.

[9]  C. Bierlich,et al.  Effects of color reconnection on hadron flavor observables , 2015, 1507.02091.

[10]  P. Skands,et al.  Tuning PYTHIA 8.1: the Monash 2013 tune , 2014, 1404.5630.

[11]  G. R. Lee,et al.  K-S(0) and Lambda Production in Pb-Pb Collisions at root s(NN)=2: 76 TeV , 2013 .

[12]  Z. A. Ibrahim,et al.  Measurement of charm fragmentation fractions in photoproduction at HERA , 2013, 1306.4862.

[13]  N. K. Behera,et al.  Strangeness enhancement in Cu-Cu and Au-Au collisions at √S(NN)=200 GeV. , 2011, Physical review letters.

[14]  W. Llope.  Multigap RPCs in the STAR experiment at RHIC , 2012 .

[15]  S. H. Lee,et al.  Ratios of heavy baryons to heavy mesons in relativistic nucleus-nucleus collisions , 2009 .

[16]  et al,et al.  Systematic measurements of identified particle spectra in pp, d+Au, and Au+Au collisions at the STAR detector , 2008, 0808.2041.

[17]  J. Cleymans,et al.  THERMUS - A thermal model package for ROOT , 2004, Comput. Phys. Commun..

[18]  V. Greco,et al.  Coalescence Models for Hadron Formation from Quark-Gluon Plasma , 2008, 0807.4939.

[19]  I. Yoo,et al.  Lambdac enhancement from strongly coupled quark-gluon plasma. , 2007, Physical review letters.

[20]  Star Collaboration.  Energy dependence of charged pion, proton and anti-proton transverse momentum spectra for Au+Au collisions at \sqrt{s_NN} = 62.4 and 200 GeV , 2007, nucl-ex/0703040.

[21]  C. Henderson,et al.  The PHOBOS Perspective on Discoveries at RHIC , 2005 .

[22]  E. al.,et al.  Experimental and theoretical challenges in the search for the quark-gluon plasma: The STAR Collaboration's critical assessment of the evidence from RHIC collisions , 2005, nucl-ex/0501009.

[23]  E. al.,et al.  Quark gluon plasma and color glass condensate at RHIC? The Perspective from the BRAHMS experiment , 2004, nucl-ex/0410020.

[24]  E. al.,et al.  Formation of dense partonic matter in relativistic nucleus–nucleus collisions at RHIC: Experimental evaluation by the PHENIX Collaboration , 2004, nucl-ex/0410003.

[25]  V. Greco,et al.  Quark coalescence for charmed mesons in ultrarelativistic heavy-ion collisions , 2003, nucl-th/0312100.

[26]  F. Geurts,et al.  The TOFp/pVPD time-of-flight system for STAR , 2003, nucl-ex/0308022.

[27]  Zi-Wei Lin,et al.  Quark coalescence and elliptic flow of charm hadrons , 2003, nucl-th/0304045.

[28]  J. Thomas,et al.  The STAR time projection chamber: a unique tool for studying high multiplicity events at RHIC , 2003, nucl-ex/0301015.

[29]  A. Dell'Acqua,et al.  Geant4 - A simulation toolkit , 2003 .

[30]  S. Mrenna,et al.  Pythia 6.3 physics and manual , 2003, hep-ph/0308153.

[31]  D. Lange,et al.  The EvtGen particle decay simulation package , 2001 .

[32]  R. Barate,et al.  Study of charm production in Z decays , 2000 .

[33]  Hayes,et al.  Review of Particle Physics. , 1996, Physical review. D, Particles and fields.

[34]  M. Gyulassy,et al.  HIJING 1.0: A Monte Carlo program for parton and particle production in high energy hadronic and nuclear collisions , 1994, nucl-th/9502021.