Abstract

Background: In the context of the investigation of the quark gluon plasma produced in heavy-ion collisions, hadrons containing heavy (charm or beauty) quarks play a special role for the characterization of the hot and dense medium created in the interaction. The measurement of the production of charm and beauty hadrons in proton-proton collisions, besides providing the necessary reference for the studies in heavy-ion reactions, constitutes an important test of perturbative quantum chromodynamics (pQCD) calculations. Heavy-flavor production in proton-nucleus collisions is sensitive to the various effects related to the presence of nuclei in the colliding system, commonly denoted cold-nuclear-matter effects. Most of these effects are expected to modify open-charm production at low transverse momenta (p(T)) and, so far, no measurement of D-meson production down to zero transverse momentum was available at mid-rapidity at the energies attained at the CERN Large Hadron Collider (LHC). Purpose: The measurements of the production cross sections of promptly produced charmed mesons in p-Pb collisions at the LHC down to p(T) = 0 and the comparison to the results from pp interactions are aimed at the assessment of cold-nuclear-matter effects on open-charm production, which is crucial for the interpretation of the results from Pb-Pb collisions. The prompt charmed mesons D-0, D+, D*+, and D-s(+) were measured at mid-rapidity in p-Pb collisions at a center-of-mass energy per nucleon pair root S-NN = 5.02 TeV with the ALICE detector at the LHC. D mesons were reconstructed from their decays D-0 -> K- pi(+), D+ -> K- pi(+) pi(+), D*+ -> D-0 pi(+), D-S(+) -> phi pi(+) -> K- K+ pi(+), and their charge conjugates, using an analysis method based on the selection of decay topologies displaced from the interaction vertex. In addition, the prompt D 0 production cross section was measured in pp collisions at root S = 7 TeV and p-Pb collisions at root S-NN = 5.02 TeV down to p(T) = 0 using an analysis technique that is based on the estimation and subtraction of the combinatorial background, without reconstruction of the D-0 decay vertex. Results: The production cross section in pp collisions is described within uncertainties by different implementations of pQCD calculations down to p(T) = 0. This allowed also a determination of the total c (c) over bar production cross section in pp collisions, which is more precise than previous ALICE measurements because it is not affected by uncertainties owing to the extrapolation to pT = 0. The nuclear modification factor R-pPb( p(T)), defined as the ratio of the p(T)-differential D meson cross section in p-Pb collisions and that in pp collisions scaled by the mass number of the Pb nucleus, was calculated for the four D-meson species and found to be compatible with unity within uncertainties. The results are compared to theoretical calculations that include cold-nuclear-matter effects and to transport model calculations incorporating the interactions of charm quarks with an expanding deconfined medium. Conclusions: These measurements add experimental evidence that the modification of the D-meson transverse momentum distributions observed in Pb-Pb collisions with respect to pp interactions is due to strong final-state effects induced by the interactions of the charm quarks with the hot and dense partonic medium created in ultrarelativistic heavy-ion collisions. The current precision of the measurement does not allow us to draw conclusions on the role of the different cold-nuclear-matter effects and on the possible presence of additional hot-medium effects in p-Pb collisions. However, the analysis technique without decay-vertex reconstruction, applied on future larger data samples, should provide access to the physics-rich range down to p(T) = 0.

Autore Pugliese

• Mastroserio Annalisa

Tutti gli autori

• Adam J. , Adamová D. , Aggarwal M. M. , Aglieri Rinella G. , Agnello M. , Agrawal N. , Ahammed Z. , Ahmad S. , Ahn S. U. , Aiola S. , Akindinov A. , Alam S. N. , Albuquerque D. S. D. , Aleksandrov D. , Alessandro B. , Alexandre D. , Alfaro Molina R. , Alici A. , Alkin A. , Alme J. , Alt T. , Altinpinar S. , Altsybeev I. , Alves Garcia Prado C. , Andrei C. , Andronic A. , Anguelov V. , Antičić T. , Antinori F. , Antonioli P. , Aphecetche L. , Appelshäuser H. , Arcelli S. , Arnaldi R. , Arnold O. W. , Arsene I. C. , Arslandok M. , Audurier B. , Augustinus A. , Averbeck R. , Azmi M. D. , Badalà A. , Baek Y. W. , Bagnasco S. , Bailhache R. , Bala R. , Balasubramanian S. , Baldisseri A. , Baral R. C. , Barbano A. M. , Barbera R. , Barile F. , Barnaföldi G. G. , Barnby L. S. , Barret V. , Bartalini P. , Barth K. , Bartke J. , Bartsch E. , Basile M. , Bastid N. , Basu S. , Bathen B. , Batigne G. , Batista Camejo A. , Batyunya B. , Batzing P. C. , Bearden I. G. , Beck H. , Bedda C. , Behera N. K. , Belikov I. , Bellini F. , Bello Martinez H. , Bellwied R. , Belmont R. , Belmont Moreno E. , Beltran L. G. E. , Belyaev V. , Bencedi G. , Beole S. , Berceanu I. , Bercuci A. , Berdnikov Y. , Berenyi D. , Bertens R. A. , Berzano D. , Betev L. , Bhasin A. , Bhat I. R. , Bhati A. K. , Bhattacharjee B. , Bhom J. , Bianchi L. , Bianchi N. , Bianchin C. , Bielčík J. , Bielčíková J. , Bilandzic A. , Biro G. , Biswas R. , Biswas S. , Bjelogrlic S. , Blair J. T. , Blau D. , Blume C. , Bock F. , Bogdanov A. , Bøggild H. , Boldizsár L. , Bombara M. , Bonora M. , Book J. , Borel H. , Borissov A. , Borri M. , Bossú F. , Botta E. , Bourjau C. , Braun Munzinger P. , Bregant M. , Breitner T. , Broker T. A. , Browning T. A. , Broz M. , Brucken E. J. , Bruna E. , Bruno G. E. , Budnikov D. , Buesching H. , Bufalino S. , Buncic P. , Busch O. , Buthelezi Z. , Butt J. B. , Buxton J. T. , Cabala J. , Caffarri D. , Cai X. , Caines H. , Calero Diaz L. , Caliva A. , Calvo Villar E. , Camerini P. , Carena F. , Carena W. , Carnesecchi F. , Castillo Castellanos J. , Castro A. J. , Casula E. A. R. , Ceballos Sanchez C. , Cepila J. , Cerello P. , Cerkala J. , Chang B. , Chapeland S. , Chartier M. , Charvet J. L. , Chattopadhyay S. , Chattopadhyay S. , Chauvin A. , Chelnokov V. , Cherney M. , Cheshkov C. , Cheynis B. , Chibante Barroso V. , Chinellato D. D. , Cho S. , Chochula P. , Choi K. , Chojnacki M. , Choudhury S. , Christakoglou P. , Christensen C. H. , Christiansen P. , Chujo T. , Chung S. U. , Cicalo C. , Cifarelli L. , Cindolo F. , Cleymans J. , Colamaria F. , Colella D. , Collu A. , Colocci M. , Conesa Balbastre G. , Conesa Del Valle Z. , Connors M. E. , Contreras J. G. , Cormier T. M. , Corrales Morales Y. , Cortés Maldonado I. , Cortese P. , Cosentino M. R. , Costa F. , Crkovska J. , Crochet P. , Cruz Albino R. , Cuautle E. , Cunqueiro L. , Dahms T. , Dainese A. , Danisch M. C. , Danu A. , Das D. , Das I. , Das S. , Dash A. , Dash S. , De S. , De Caro A. , De Cataldo G. , De Conti C. , De Cuveland J. , De Falco A. , De Gruttola D. , De Marco N. , De Pasquale S. , De Souza R. D. , Deisting A. , Deloff A. , Dénes E. , Deplano C. , Dhankher P. , Di Bari D. , Di Mauro A. , Di Nezza P. , Di Ruzza B. , Diaz Corchero M. A. , Dietel T. , Dillenseger P. , Divià R. , Djuvsland Dobrin , Domenicis Gimenez D. , Dönigus B. , Dordic O. , Drozhzhova T. , Dubey A. K. , Dubla A. , Ducroux L. , Dupieux P. , Ehlers R. J. , Elia D. , Endress E. , Engel H. , Epple E. , Erazmus B. , Erdemir I. , Erhardt F. , Espagnon B. , Estienne M. , Esumi S. , Eum J. , Evans D. , Evdokimov S. , Eyyubova G. , Fabbietti L. , Fabris D. , Faivre J. , Fantoni A. , Fasel M. , Feldkamp L. , Feliciello A. , Feofilov G. , Ferencei J. , Fernández Téllez A. , Ferreiro E. G. , Ferretti A. , Festanti A. , Feuillard V. J. G. , Figiel J. , Figueredo M. A. S. , Filchagin S. , Finogeev D. , Fionda F. M. , Fiore E. M. , Fleck M. G. , Floris M. , Foertsch S. , Foka

Titolo volume/Rivista

PHYSICAL REVIEW C

Anno di pubblicazione

2016

ISSN

2469-9985

ISBN

Non Disponibile

Numero di citazioni Wos

8

Ultimo Aggiornamento Citazioni

Non Disponibile

Numero di citazioni Scopus

11

Ultimo Aggiornamento Citazioni

Non Disponibile

Settori ERC

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Codici ASJC

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