Measurement of prompt hadron production ratios in $pp$ collisions at
$\sqrt{s} = $ 0.9 and 7 TeV
ArXiv 1206.516 (2012)
Authors:
LHCb collaboration, R Aaij, C Abellan Beteta, A Adametz, B Adeva, M Adinolfi, C Adrover, A Affolder, Z Ajaltouni, J Albrecht, F Alessio, M Alexander, S Ali, G Alkhazov, P Alvarez Cartelle, AA Alves Jr, S Amato, Y Amhis, J Anderson, RB Appleby, O Aquines Gutierrez, F Archilli, A Artamonov, M Artuso, E Aslanides, G Auriemma, S Bachmann, JJ Back, V Balagura, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, A Bates, C Bauer, Th Bauer, A Bay, J Beddow, I Bediaga, S Belogurov, K Belous, I Belyaev, E Ben-Haim, M Benayoun, G Bencivenni, S Benson, J Benton, A Berezhnoy, R Bernet, M-O Bettler, M van Beuzekom, A Bien, S Bifani, T Bird, A Bizzeti, PM Bjørnstad, T Blake, F Blanc, C Blanks, J Blouw, S Blusk, A Bobrov, V Bocci, A Bondar, N Bondar, W Bonivento, S Borghi, A Borgia, TJV Bowcock, C Bozzi, T Brambach, J van den Brand, J Bressieux, D Brett, M Britsch, T Britton, NH Brook, H Brown, A Büchler-Germann, I Burducea, A Bursche, J Buytaert, S Cadeddu, O Callot, M Calvi, M Calvo Gomez, A Camboni, P Campana, A Carbone, G Carboni, R Cardinale, A Cardini, L Carson, K Carvalho Akiba, G Casse, M Cattaneo, Ch Cauet, M Charles, Ph Charpentier, P Chen, N Chiapolini, M Chrzaszcz, K Ciba, X Cid Vidal, G Ciezarek, PEL Clarke, M Clemencic, HV Cliff, J Closier, C Coca, V Coco, J Cogan, E Cogneras, P Collins, A Comerma-Montells, A Contu, A Cook, M Coombes, G Corti, B Couturier, GA Cowan, D Craik, R Currie, C D'Ambrosio, P David, PNY David, I De Bonis, K De Bruyn, S De Capua, M De Cian, JM De Miranda, L De Paula, P De Simone, D Decamp, M Deckenhoff, H Degaudenzi, L Del Buono, C Deplano, D Derkach, O Deschamps, F Dettori, J Dickens, H Dijkstra, P Diniz Batista, F Domingo Bonal, S Donleavy, F Dordei, A Dosil Suárez, D Dossett, A Dovbnya, F Dupertuis, R Dzhelyadin, A Dziurda, A Dzyuba, S Easo, U Egede, V Egorychev, S Eidelman, D van Eijk, F Eisele, S Eisenhardt, R Ekelhof, L Eklund, I El Rifai, Ch Elsasser, D Elsby, D Esperante Pereira, A Falabella, C Färber, G Fardell, C Farinelli, S Farry, V Fave, V Fernandez Albor, F Ferreira Rodrigues, M Ferro-Luzzi, S Filippov, C Fitzpatrick, M Fontana, F Fontanelli, R Forty, O Francisco, M Frank, C Frei, M Frosini, S Furcas, A Gallas Torreira, D Galli, M Gandelman, P Gandini, Y Gao, J-C Garnier, J Garofoli, J Garra Tico, L Garrido, D Gascon, C Gaspar, R Gauld, N Gauvin, E Gersabeck, M Gersabeck, T Gershon, Ph Ghez, V Gibson, VV Gligorov, C Göbel, D Golubkov, A Golutvin, A Gomes, H Gordon, M Grabalosa Gándara, R Graciani Diaz, LA Granado Cardoso, E Graugés, G Graziani, A Grecu, E Greening, S Gregson, O Grünberg, B Gui, E Gushchin, Yu Guz, T Gys, C Hadjivasiliou, G Haefeli, C Haen, SC Haines, T Hampson, S Hansmann-Menzemer, N Harnew, ST Harnew, J Harrison, PF Harrison, T Hartmann, J He, V Heijne, K Hennessy, P Henrard, JA Hernando Morata, E van Herwijnen, E Hicks, D Hill, M Hoballah, P Hopchev, W Hulsbergen, P Hunt, T Huse, N Hussain, RS Huston, D Hutchcroft, D Hynds, V Iakovenko, P Ilten, J Imong, R Jacobsson, A Jaeger, M Jahjah Hussein, E Jans, F Jansen, P Jaton, B Jean-Marie, F Jing, M John, D Johnson, CR Jones, B Jost, M Kaballo, S Kandybei, M Karacson, TM Karbach, J Keaveney, IR Kenyon, U Kerzel, T Ketel, A Keune, B Khanji, YM Kim, M Knecht, O Kochebina, I Komarov, RF Koopman, P Koppenburg, M Korolev, A Kozlinskiy, L Kravchuk, K Kreplin, M Kreps, G Krocker, P Krokovny, F Kruse, K Kruzelecki, M Kucharczyk, V Kudryavtsev, T Kvaratskheliya, VN La Thi, D Lacarrere, G Lafferty, A Lai, D Lambert, RW Lambert, E Lanciotti, G Lanfranchi, C Langenbruch, T Latham, C Lazzeroni, R Le Gac, J van Leerdam, J-P Lees, R Lefèvre, A Leflat, J Lefrançois, O Leroy, T Lesiak, L Li, Y Li, L Li Gioi, M Lieng, M Liles, R Lindner, C Linn, B Liu, G Liu, J von Loeben, JH Lopes, E Lopez Asamar, N Lopez-March, H Lu, J Luisier, A Mac Raighne, F Machefert, IV Machikhiliyan, F Maciuc, O Maev, J Magnin, S Malde, RMD Mamunur, G Manca, G Mancinelli, N Mangiafave, U Marconi, R Märki, J Marks, G Martellotti, A Martens, L Martin, A Martín Sánchez, M Martinelli, D Martinez Santos, A Massafferri, Z Mathe, C Matteuzzi, M Matveev, E Maurice, B Maynard, A Mazurov, J McCarthy, G McGregor, R McNulty, M Meissner, M Merk, J Merkel, DA Milanes, M-N Minard, J Molina Rodriguez, S Monteil, D Moran, P Morawski, R Mountain, I Mous, F Muheim, K Müller, R Muresan, B Muryn, B Muster, J Mylroie-Smith, P Naik, T Nakada, R Nandakumar, I Nasteva, M Needham, N Neufeld, AD Nguyen, C Nguyen-Mau, M Nicol, V Niess, N Nikitin, T Nikodem, A Nomerotski, A Novoselov, A Oblakowska-Mucha, V Obraztsov, S Oggero, S Ogilvy, O Okhrimenko, R Oldeman, M Orlandea, JM Otalora Goicochea, P Owen, BK Pal, J Palacios, A Palano, M Palutan, J Panman, A Papanestis, M Pappagallo, C Parkes, CJ Parkinson, G Passaleva, GD Patel, M Patel, GN Patrick, C Patrignani, C Pavel-Nicorescu, A Pazos Alvarez, A Pellegrino, G Penso, M Pepe Altarelli, S Perazzini, DL Perego, E Perez Trigo, A Pérez-Calero Yzquierdo, P Perret, M Perrin-Terrin, G Pessina, A Petrolini, A Phan, E Picatoste Olloqui, B Pie Valls, B Pietrzyk, T Pilař, D Pinci, R Plackett, S Playfer, M Plo Casasus, F Polci, G Polok, A Poluektov, E Polycarpo, D Popov, B Popovici, C Potterat, A Powell, J Prisciandaro, V Pugatch, A Puig Navarro, W Qian, JH Rademacker, B Rakotomiaramanana, MS Rangel, I Raniuk, G Raven, S Redford, MM Reid, AC dos Reis, S Ricciardi, A Richards, K Rinnert, DA Roa Romero, P Robbe, E Rodrigues, P Rodriguez Perez, GJ Rogers, S Roiser, V Romanovsky, M Rosello, J Rouvinet, T Ruf, H Ruiz, G Sabatino, JJ Saborido Silva, N Sagidova, P Sail, B Saitta, C Salzmann, B Sanmartin Sedes, M Sannino, R Santacesaria, C Santamarina Rios, R Santinelli, E Santovetti, M Sapunov, A Sarti, C Satriano, A Satta, M Savrie, D Savrina, P Schaack, M Schiller, H Schindler, S Schleich, M Schlupp, M Schmelling, B Schmidt, O Schneider, A Schopper, M-H Schune, R Schwemmer, B Sciascia, A Sciubba, M Seco, A Semennikov, K Senderowska, I Sepp, N Serra, J Serrano, P Seyfert, M Shapkin, I Shapoval, P Shatalov, Y Shcheglov, T Shears, L Shekhtman, O Shevchenko, V Shevchenko, A Shires, R Silva Coutinho, T Skwarnicki, NA Smith, E Smith, M Smith, K Sobczak, FJP Soler, A Solomin, F Soomro, D Souza, B Souza De Paula, B Spaan, A Sparkes, P Spradlin, F Stagni, S Stahl, O Steinkamp, S Stoica, S Stone, B Storaci, M Straticiuc, U Straumann, VK Subbiah, S Swientek, M Szczekowski, P Szczypka, T Szumlak, S T'Jampens, M Teklishyn, E Teodorescu, F Teubert, C Thomas, E Thomas, J van Tilburg, V Tisserand, M Tobin, S Tolk, S Topp-Joergensen, N Torr, E Tournefier, S Tourneur, MT Tran, A Tsaregorodtsev, N Tuning, M Ubeda Garcia, A Ukleja, U Uwer, V Vagnoni, G Valenti, R Vazquez Gomez, P Vazquez Regueiro, S Vecchi, JJ Velthuis, M Veltri, M Vesterinen, B Viaud, I Videau, D Vieira, X Vilasis-Cardona, J Visniakov, A Vollhardt, D Volyanskyy, D Voong, A Vorobyev, V Vorobyev, C Voß, H Voss, R Waldi, R Wallace, S Wandernoth, J Wang, DR Ward, NK Watson, AD Webber, D Websdale, M Whitehead, J Wicht, D Wiedner, L Wiggers, G Wilkinson, MP Williams, M Williams, FF Wilson, J Wishahi, M Witek, W Witzeling, SA Wotton, S Wright, S Wu, K Wyllie, Y Xie, F Xing, Z Xing, Z Yang, R Young, X Yuan, O Yushchenko, M Zangoli, M Zavertyaev, F Zhang, L Zhang, WC Zhang, Y Zhang, A Zhelezov, L Zhong, A Zvyagin
Abstract:
The charged-particle production ratios $\bar{p}/p$, $K^-/K^+$, $\pi^-/\pi^+$,
$(p + \bar{p})/(\pi^+ + \pi^-)$, $(K^+ + K^-)/(\pi^+ + \pi^-)$ and $(p +
\bar{p})/(K^+ + K^-)$ are measured with the LHCb detector using $0.3 {\rm
nb^{-1}}$ of $pp$ collisions delivered by the LHC at $\sqrt{s} = 0.9$ TeV and
$1.8 {\rm nb^{-1}}$ at $\sqrt{s} = 7$ TeV. The measurements are performed as a
function of transverse momentum $p_{\rm T}$ and pseudorapidity $\eta$. The
production ratios are compared to the predictions of several Monte Carlo
generator settings, none of which are able to describe adequately all
observables. The ratio $\bar{p}/p$ is also considered as a function of rapidity
loss, $\Delta y \equiv y_{\rm beam} - y$, and is used to constrain models of
baryon transport.
