Publications

2015

1. φ meson production in d + Au collisions at sNN =200 GeV

   Hodes G., Kamat P., Citron Z. H., Fraenkel Z., Milov A., Tserruya I., Naglis M., Ravinovich I., Sharma D., Tarafdar S. et al. (2015) Physical Review C. 92, 4, 044909.  Abstract

   The PHENIX Collaboration has measured φ meson production in d+Au collisions at sNN=200 GeV using the dimuon and dielectron decay channels. The φ meson is measured in the forward (backward) d-going (Au-going) direction, 1.2y2.2 (-2.2y-1.2) in the transverse-momentum (pT) range from 1-7 GeV/c and at midrapidity y0.35 in the pT range below 7 GeV/c. The φ meson invariant yields and nuclear-modification factors as a function of pT, rapidity, and centrality are reported. An enhancement of φ meson production is observed in the Au-going direction, while suppression is seen in the d-going direction, and no modification is observed at midrapidity relative to the yield in p+p collisions scaled by the number of binary collisions. Similar behavior was previously observed for inclusive charged hadrons and open heavy flavor, indicating similar cold-nuclear-matter effects.

   [All authors]
2. Systematic study of charged-pion and kaon femtoscopy in Au + Au collisions at s NN =200 GeV

   Adare A., Afanasiev S., Aidala C., Ajitanand N. N., Akiba Y., Al-Bataineh H., Alexander J., Alfred M., Aoki K., Apadula N., Aramaki Y., Asano H., Atomssa E. T., Averbeck R., Awes T. C., Azmoun B., Babintsev V., Bai M., Baksay G., Baksay L., Bandara N. S., Bannier B., Barish K. N., Bassalleck B., Basye A. T., Bathe S., Baublis V., Baumann C., Bazilevsky A., Beaumier M., Beckman S., Belikov S., Belmont R., Bennett R., Berdnikov A., Berdnikov Y., Bickley A. A., Blau D. S., Bok J. S., Boyle K., Brooks M. L., Bryslawskyj J., Buesching H., Bumazhnov V., Bunce G., Butsyk S., Camacho C. M., Campbell S., Chen C. -., Chi C. Y., Chiu M., Choi I. J., Choi J. B., Choudhury R. K., Christiansen P., Chujo T., Chung P., Chvala O., Cianciolo V., Citron Z. H., Cole B. A., Connors M., Constantin P., Csanad M., Csoergo T., Dahms T., Dairaku S., Danchev I., Danley D., Das K., Datta A., Daugherity M. S., David G., DeBlasio K., Dehmelt K., Denisov A., Deshpande A., Desmond E. J., Dietzsch O., Dion A., Diss P. B., Do J. H., Donadelli M., Drapier O., Drees A., Drees K. A., Durham J. M., Durum A., Dutta D., Edwards S., Efremenko Y. V., Ellinghaus F., Engelmore T., Enokizono A., En'yo H., Esumi S., Fadem B., Feege N., Fields D. E., Finger M., Finger M. J., Fleuret F., Fokin S. L., Fraenkel Z., Frantz J. E., Franz A., Frawley A. D., Fujiwara K., Fukao Y., Fusayasu T., Gal C., Gallus P., Garg P., Garishvili I., Ge H., Giordano F., Glenn A., Gong H., Gonin M., Goto Y., de Cassagnac C. R. G., Grau N., Greene S. V., Perdekamp M. G., Gunji T., Gustafsson H. -., Hachiya T., Haggerty J. S., Hahn K. I., Hamagaki H., Hamblen J., Hamilton H. F., Han R., Han S. Y., Hanks J., Hartouni E. P., Hasegawa S., Haseler T. O. S., Hashimoto K., Haslum E., Hayano R., He X., Heffner M., Hemmick T. K., Hester T., Hill J. C., Hohlmann M., Hollis R. S., Holzmann W., Homma K., Hong B., Horaguchi T., Hornback D., Hoshino T., Hotvedt N., Huang J., Huang S. -. J., Ichihara T., Ichimiya R., Ide J., Ikeda Y., Imai K., Inaba M., Iordanova A., Isenhower D., Ishihara M., Isobe T., Issah M., Isupov A., Ivanishchev D., Jacak B. V., Jezghani M., Jia J., Jiang X., Jin J., Johnson B. M., Joo K. S., Jouan D., Jumper D. S., Kajihara F., Kametani S., Kamihara N., Kamin J., Kanda S., Kang J. H., Kapustinsky J., Karatsu K., Kawall D., Kawashima M., Kazantsev A. V., Kempel T., Key J. A., Khachatryan V., Khanzadeev A., Kijima K. M., Kim B. I., Kim C., Kim D. H., Kim D. J., Kim E., Kim E. -., Kim G. W., Kim M., Kim S. H., Kim Y. -., Kimelman B., Kinney E., Kiriluk K., Kiss A., Kistenev E., Kitamura R., Klatsky J., Kleinjan D., Kline P., Koblesky T., Kochenda L., Komkov B., Konno M., Koster J., Kotchetkov D., Kotov D., Kozlov A., Kral A., Kravitz A., Kunde G. J., Kurita K., Kurosawa M., Kwon Y., Kyle G. S., Lacey R., Lai Y. S., Lajoie J. G., Lebedev A., Lee D. M., Lee J., Lee K., Lee K. B., Lee K. S., Lee S. J., Lee S. H., Leitch M. J., Leite M. A. L., Leitner E., Lenzi B., Li X., Liebing P., Lim S. H., Levy L. A. L., Liska T., Litvinenko A., Liu H., Liu M. X., Love B., Luechtenborg R., Lynch D., Maguire C. F., Makdisi Y. I., Makek M., Malakhov A., Malik M. D., Manion A., Manko V. I., Mannel E., Mao Y., Masui H., Matathias F., McCumber M., McGaughey P. L., McGlinchey D., McKinney C., Means N., Meles A., Mendoza M., Meredith B., Miake Y., Mignerey A. C., Mikes P., Miki K., Milov A., Mishra D. K., Mishra M., Mitchell J. T., Miyasaka S., Mizuno S., Mohanty A. K., Montuenga P., Moon T., Morino Y., Morreale A., Morrison D. P., Moukhanova T. V., Murakami T., Murata J., Mwai A., Nagamiya S., Nagashima K., Nagle J. L., Naglis M., Nagy M. I., Nakagawa I., Nakagomi H., Nakamiya Y., Nakamura T., Nakano K., Nattrass C., Netrakanti P. K., Newby J., Nguyen M., Niida T., Nishimura S., Nouicer R., Novak T., Novitzky N., Nyanin A. S., O'Brien E., Oda S. X., Ogilvie C. A., Oka M., Okada K., Onuki Y., Koop J. D. O., Osborn J. D., Oskarsson A., Ouchida M., Ozawa K., Pak R., Pantuev V., Papavassiliou V., Park I. H., Park J., Park J. S., Park S., Park S. K., Park W. J., Pate S. F., Patel M., Pei H., Peng J. -., Pereira H., Perepelitsa D. V., Perera G. D. N., Peresedov V., Peressounko D. Y., Perry J., Petti R., Pinkenburg C., Pinson R., Pisani R. P., Proissl M., Purschke M. L., Purwar A. K., Qu H., Rak J., Rakotozafindrabe A., Ramson B. J., Ravinovich I., Read K. F., Reygers K., Reynolds D., Riabov V., Riabov Y., Richardson E., Rinn T., Roach D., Roche G., Rolnick S. D., Rosati M., Rosen C. A., Rosendahl S. S. E., Rosnet P., Rowan Z., Rubin J. G., Rukoyatkin P., Ruzicka P., Sahlmueller B., Saito N., Sakaguchi T., Sakashita K., Sako H., Samsonov V., Sano S., Sarsour M., Sato S., Sato T., Sawada S., Schaefer B., Schmoll B. K., Sedgwick K., Seele J., Seidl R., Semenov A. Y., Sen A., Seto R., Sett P., Sexton A., Sharma D., Shein I., Shibata T. -., Shigaki K., Shimomura M., Shoji K., Shukla P., Sickles A., Silva C. L., Silvermyr D., Silvestre C., Sim K. S., Singh B. K., Singh C. P., Singh V., Slunecka M., Snowball M., Soltz R. A., Sondheim W. E., Sorensen S. P., Sourikova I. V., Sparks N. A., Stankus P. W., Stenlund E., Stepanov M., Stoll S. P., Sugitate T., Sukhanov A., Sumita T., Sun J., Sziklai J., Takagui E. M., Taketani A., Tanabe R., Tanaka Y., Tanida K., Tannenbaum M. J., Tarafdar S., Taranenko A., Tarjan P., Themann H., Thomas T. L., Tieulent R., Timilsina A., Todoroki T., Togawa M., Toia A., Tomasek L., Tomasek M., Torii H., Towell C. L., Towell R., Towell R. S., Tserruya I., Tsuchimoto Y., Vale C., Valle H., van Hecke H. H. W., Vazquez-Zambrano E., Veicht A., Velkovska J., Vertesi R., Vinogradov A. A., Virius M., Vrba V., Vznuzdaev E., Wang X. R., Watanabe D., Watanabe K., Watanabe Y., Watanabe Y. S., Wei F., Wei R., Wessels J., White A. S., White S. N., Winter D., Wood J. P., Woody C. L., Wright R. M., Wysocki M., Xia B., Xie W., Xue L., Yalcin S., Yamaguchi Y. L., Yamaura K., Yang R., Yanovich A., Ying J., Yokkaichi S., Yoo J. H., Yoon I., You Z., Young G. R., Younus I., Yu H., Yushmanov I. E., Zajc W. A., Zelenski A., Zhang C., Zhou S., Zolin L., Zou L. et al. (2015) Physical Review C. 92, 3, 034914.  Abstract

   We present a systematic study of charged-pion and kaon interferometry in Au+Au collisions at sNN=200 GeV. The kaon mean source radii are found to be larger than pion radii in the outward and longitudinal directions for the same transverse mass; this difference increases for more central collisions. The azimuthal-angle dependence of the radii was measured with respect to the second-order event plane and similar oscillations of the source radii were found for pions and kaons. Hydrodynamic models qualitatively describe the similar oscillations of the mean source radii for pions and kaons, but they do not fully describe the transverse-mass dependence of the oscillations.

   [All authors]
3. Measurements of Elliptic and Triangular Flow in High-Multiplicity He 3 +Au Collisions at sNN =200GeV

   Adare A., Afanasiev S., Aidala C., Ajitanand N. N., Akiba Y., Akimoto R., Al-Bataineh H., Alexander J., Alfred M., Al-Ta'ani H., Andrews K. R., Angerami A., Aoki K., Apadula N., Aphecetche L., Appelt E., Aramaki Y., Armendariz R., Aronson S. H., Asai J., Asano H., Aschenauer E. C., Atomssa E. T., Averbeck R., Awes T. C., Azmoun B., Babintsev V., Bai M., Baksay G., Baksay L., Baldisseri A., Bandara N. S., Bannier B., Barish K. N., Barnes P. D., Bassalleck B., Basye A. T., Bathe S., Batsouli S., Baublis V., Baumann C., Bazilevsky A., Beaumier M., Beckman S., Belikov S., Belmont R., Ben-Benjamin J., Bennett R., Berdnikov A., Berdnikov Y., Bhom J. H., Bickley A. A., Blau D. S., Boissevain J. G., Bok J. S., Borel H., Boyle K., Brooks M. L., Broxmeyer D., Bryslawskyj J., Buesching H., Bumazhnov V., Bunce G., Butsyk S., Camacho C. M., Campbell S., Caringi A., Castera P., Chang B. S., Chang W. C., Charvet J. -., Chen C. -., Chernichenko S., Chi C. Y., Chiba J., Chiu M., Choi I. J., Choi J. B., Choudhury R. K., Christiansen P., Chujo T., Chung P., Churyn A., Chvala O., Cianciolo V., Citron Z. H., Cleven C. R., Cole B. A., Comets M. P., del Valle V. Z. C., Connors M., Constantin P., Csanad M., Csoergo T., Dahms T., Dairaku S., Danchev I., Danley D., Das K., Datta A., Daugherity M. S., David G., Dayananda M. K., Deaton M. B., DeBlasio K., Dehmelt K., Delagrange H., Denisov A., d'Enterria D., Deshpande A., Desmond E. J., Dharmawardane K. V., Dietzsch O., Dion A., Diss P. B., Do J. H., Donadelli M., D'Orazio L., Drapier O., Drees A., Drees K. A., Dubey A. K., Durham J. M., Durum A., Dutta D., Dzhordzhadze V., Edwards S., Efremenko Y. V., Egdemir J., Ellinghaus F., Emam W. S., Engelmore T., Enokizono A., En'yo H., Esumi S., Eyser K. O., Fadem B., Feege N., Fields D. E., Finger M., Finger M. J., Fleuret F., Fokin S. L., Fraenkel Z., Frantz J. E., Franz A., Frawley A. D., Fujiwara K., Fukao Y., Fusayasu T., Gadrat S., Gal C., Gallus P., Garg P., Garishvili I., Ge H., Giordano F., Glenn A., Gong H., Gong X., Gonin M., Gosset J., Goto Y., de Cassagnac C. R. G., Grau N., Greene S. V., Grim G., Perdekamp M. G., Gu Y., Gunji T., Guo L., Gustafsson H. -., Hachiya T., Henni A. H., Haegemann C., Haggerty J. S., Hahn K. I., Hamagaki H., Hamblen J., Hamilton H. F., Han R., Han S. Y., Hanks J., Harada H., Harper C., Hartouni E. P., Haruna K., Hasegawa S., Haseler T. O. S., Hashimoto K., Haslum E., Hayano R., He X., Heffner M., Hemmick T. K., Hester T., Hiejima H., Hill J. C., Hobbs R., Hohlmann M., Hollis R. S., Holzmann W., Homma K., Hong B., Horaguchi T., Hori Y., Hornback D., Hoshino T., Hotvedt N., Huang J., Huang S. -. J., Ichihara T., Ichimiya R., Iinuma H., Ikeda Y., Imai K., Imrek J., Inaba M., Inoue Y., Iordanova A., Isenhower D., Isenhower L., Ishihara M., Isobe T., Issah M., Isupov A., Ivanishchev D., Iwanaga Y., Jacak B. V., Jezghani M., Jia J., Jiang X., Jin J., Jinnouchi O., John D., Johnson B. M., Jones T., Joo K. S., Jouan D., Jumper D. S., Kajihara F., Kametani S., Kamihara N., Kamin J., Kanda S., Kaneta M., Kaneti S., Kang B. H., Kang J. H., Kang J. S., Kanou H., Kapustinsky J., Karatsu K., Kasai M., Kawall D., Kawashima M., Kazantsev A. V., Kempel T., Key J. A., Khachatryan V., Khanzadeev A., Kijima K. M., Kikuchi J., Kim A., Kim B. I., Kim C., Kim D. H., Kim D. J., Kim E., Kim E. -., Kim G. W., Kim M., Kim S. H., Kim Y. -., Kim Y. K., Kimelman B., Kinney E., Kiriluk K., Kiss A., Kistenev E., Kitamura R., Kiyomichi A., Klatsky J., Klay J., Klein-Boesing C., Kleinjan D., Kline P., Koblesky T., Kochenda L., Kochetkov V., Komkov B., Konno M., Koster J., Kotchetkov D., Kotov D., Kozlov A., Kral A., Kravitz A., Kubart J., Kunde G. J., Kurihara N., Kurita K., Kurosawa M., Kweon M. J., Kwon Y., Kyle G. S., Lacey R., Lai Y. S., Lajoie J. G., Layton D., Lebedev A., Lee D. M., Lee J., Lee K. B., Lee K. S., Lee M. K., Lee S. J., Lee S. H., Lee S. R., Lee T., Leitch M. J., Leite M. A. L., Lenzi B., Li X., Lichtenwalner P., Liebing P., Lim S. H., Levy L. A. L., Liska T., Litvinenko A., Liu H., Liu M. X., Love B., Lynch D., Maguire C. F., Makdisi Y. I., Makek M., Malakhov A., Malik M. D., Manion A., Manko V. I., Mannel E., Mao Y., Masek L., Masui H., Matathias F., McCumber M., McGaughey P. L., McGlinchey D., McKinney C., Means N., Meles A., Mendoza M., Meredith B., Miake Y., Mibe T., Mignerey A. C., Mikes P., Miki K., Miller T. E., Milov A., Mioduszewski S., Mishra D. K., Mishra M., Mitchell J. T., Mitrovski M., Miyachi Y., Miyasaka S., Mizuno S., Mohanty A. K., Montuenga P., Moon H. J., Moon T., Morino Y., Morreale A., Morrison D. P., Motschwiller S., Moukhanova T. V., Mukhopadhyay D., Murakami T., Murata J., Mwai A., Nagamiya S., Nagashima K., Nagata Y., Nagle J. L., Naglis M., Nagy M. I., Nakagawa I., Nakagomi H., Nakamiya Y., Nakamura K. R., Nakamura T., Nakano K., Nam S., Nattrass C., Netrakanti P. K., Newby J., Nguyen M., Nihashi M., Niida T., Nishimura S., Norman B. E., Nouicer R., Novak T., Novitzky N., Nyanin A. S., Oakley C., O'Brien E., Oda S. X., Ogilvie C. A., Ohnishi H., Oka M., Okada K., Omiwade O. O., Onuki Y., Koop J. D. O., Osborn J. D., Oskarsson A., Ouchida M., Ozawa K., Pak R., Pal D., Palounek A. P. T., Pantuev V., Papavassiliou V., Park B. H., Park I. H., Park J., Park J. S., Park S., Park S. K., Park W. J., Pate S. F., Patel L., Patel M., Pei H., Peng J. -., Pereira H., Perepelitsa D. V., Perera G. D. N., Peresedov V., Peressounko D. Y., Perry J., Petti R., Pinkenburg C., Pinson R., Pisani R. P., Proissl M., Purschke M. L., Purwar A. K., Qu H., Rak J., Rakotozafindrabe A., Ramson B. J., Ravinovich I., Read K. F., Rembeczki S., Reuter M., Reygers K., Reynolds D., Riabov V., Riabov Y., Richardson E., Rinn T., Roach D., Roche G., Rolnick S. D., Romana A., Rosati M., Rosen C. A., Rosendahl S. S. E., Rosnet P., Rowan Z., Rubin J. G., Rukoyatkin P., Ruzicka P., Rykov V. L., Sahlmueller B., Saito N., Sakaguchi T., Sakai S., Sakashita K., Sakata H., Sako H., Samsonov V., Sano S., Sarsour M., Sato S., Sato T., Savastio M., Sawada S., Schaefer B., Schmoll B. K., Sedgwick K., Seele J., Seidl R., Semenov A. Y., Semenov V., Sen A., Seto R., Sett P., Sexton A., Sharma D., Shein I., Shevel A., Shibata T. -., Shigaki K., Shim H. H., Shimomura M., Shoji K., Shukla P., Sickles A., Silva C. L., Silvermyr D., Silvestre C., Sim K. S., Singh B. K., Singh C. P., Singh V., Skutnik S., Slunecka M., Snowball M., Sodre T., Soldatov A., Soltz R. A., Sondheim W. E., Sorensen S. P., Sourikova I. V., Staley F., Stankus P. W., Stenlund E., Stepanov M., Ster A., Stoll S. P., Sugitate T., Suire C., Sukhanov A., Sumita T., Sun J., Sziklai J., Tabaru T., Takagi S., Takagui E. M., Takahara A., Taketani A., Tanabe R., Tanaka Y., Taneja S., Tanida K., Tannenbaum M. J., Tarafdar S., Taranenko A., Tarjan P., Tennant E., Themann H., Thomas D., Thomas T. L., Tieulent R., Timilsina A., Todoroki T., Togawa M., Toia A., Tojo J., Tomasek L., Tomasek M., Tomita Y., Torii H., Towell C. L., Towell R., Towell R. S., Tram V., Tserruya I., Tsuchimoto Y., Utsunomiya K., Vale C., Valle H., van Hecke H. H. W., Vazquez-Zambrano E., Veicht A., Velkovska J., Vertesi R., Vinogradov A. A., Virius M., Vossen A., Vrba V., Vznuzdaev E., Wagner M., Walker D., Wang X. R., Watanabe D., Watanabe K., Watanabe Y., Watanabe Y. S., Wei F., Wei R., Wessels J., White A. S., White S. N., Winter D., Woody C. L., Wright R. M., Wysocki M., Xia B., Xie W., Xue L., Yalcin S., Yamaguchi Y. L., Yamaura K., Yang R., Yanovich A., Yasin Z., Ying J., Yokkaichi S., Yoo J. H., Yoo J. S., Yoon I., You Z., Young G. R., Younus I., Yu H., Yushmanov I. E., Zajc W. A., Zaudtke O., Zelenski A., Zhang C., Zhou S., Zimamyi J., Zolin L., Zou L. et al. (2015) Physical review letters. 115, 14, 142301.  Abstract

   We present the first measurement of elliptic (v2) and triangular (v3) flow in high-multiplicity He3+Au collisions at sNN=200GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in He3+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the He3+Au system. The collective behavior is quantified in terms of elliptic v2 and triangular v3 anisotropy coefficients measured with respect to their corresponding event planes. The v2 values are comparable to those previously measured in d+Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three He3 nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.

   [All authors]
4. Systematic study of azimuthal anisotropy in Cu + Cu and Au + Au collisions at s NN =62.4 and 200 GeV SYSTEMATIC STUDY of AZIMUTHAL ANISOTROPY in ⋯ A. ADARE et al.

   Adare A., Afanasiev S., Aidala C., Ajitanand N. N., Akiba Y., Al-Bataineh H., Al-Jamel A., Alexander J., Aoki K., Aphecetche L., Armendariz R., Dubey A. K., Fraenkel Z., Kang J. H., Milov A., Park J., Ravinovich I., Sharma D., Tserruya I., Winter D. et al. (2015) Physical Review C. 92, 3, 034913.  Abstract

   We have studied the dependence of azimuthal anisotropy v2 for inclusive and identified charged hadrons in Au+Au and Cu+Cu collisions on collision energy, species, and centrality. The values of v2 as a function of transverse momentum pT and centrality in Au+Au collisions at sNN=200 and 62.4 GeV are the same within uncertainties. However, in Cu+Cu collisions we observe a decrease in v2 values as the collision energy is reduced from 200 to 62.4 GeV. The decrease is larger in the more peripheral collisions. By examining both Au+Au and Cu+Cu collisions we find that v2 depends both on eccentricity and the number of participants, Npart. We observe that v2 divided by eccentricity () monotonically increases with Npart and scales as Npart1/3. The Cu+Cu data at 62.4 GeV falls below the other scaled v2 data. For identified hadrons, v2 divided by the number of constituent quarks nq is independent of hadron species as a function of transverse kinetic energy KET=mT-m between 0.1

   [All authors]
5. Charged-Pion cross sections and double-helicity asymmetries in polarized p+p collisions at √s = 200 GeV

   Citron Z. H., Cole B. A., del Valle V. Z. C., Connors M., Csanad M., Csoergo T., Dairaku S., Datta A., David G., Dayananda M. K., Denisov A., Deshpande A., Desmond E. J., Dharmawardane K. V., Dietzsch O., Dubey A. K., Makek M., Milov A., Sharma D., Tserruya I. et al. (2015) Physical Review D. 91, 3, 032001.  Abstract

   We present midrapidity charged-pion invariant cross sections, the ratio of the π^- to π⁺ cross sections and the charge-separated double-spin asymmetries in polarized p + p collisions at p√s = 200 GeV. While the cross section measurements are consistent within the errors of next-to-leading-order (NLO) perturbative quantum chromodynamics predictions (pQCD), the same calculations overestimate the ratio of the charged-pion cross sections. This discrepancy arises from the cancellation of the substantial systematic errors associated with the NLO-pQCD predictions in the ratio and highlights the constraints these data will place on flavor-dependent pion fragmentation functions. The charge-separated pion asymmetries presented here sample an x range of ~0.03-0.16 and provide unique information on the sign of the gluon-helicity distribution.

   [All authors]
6. Measurement of Υ(1S+2S+3S) production in p+p and Au+Au collisions at √sNN=200 GeV

   Adare A., Afanasiev S., Aidala C., Ajitanand N. N., Akiba Y., Akimoto R., Al-Bataineh H., Al-Ta'ani H., Alexander J., Angerami A., Aoki K., Apadula N., Citron Z. H., Fraenkel Z., Dubey A. K., Makek M., Ravinovich I., Sharma D., Tserruya I., Milov A. et al. (2015) Physical Review C. 91, 2, 024913.  Abstract

   Measurements of bottomonium production in heavy-ion and p+p collisions at the Relativistic Heavy Ion Collider (RHIC) are presented. The inclusive yield of the three Υ states, Υ(1S+2S+3S), was measured in the PHENIX experiment via electron-positron decay pairs at midrapidity for Au+Au and p+p collisions at sNN=200 GeV. The Υ(1S+2S+3S)→e+e- differential cross section at midrapidity was found to be Beedσ/dy=108±38(stat)±15(syst)±11(luminosity) pb in p+p collisions. The nuclear modification factor in the 30% most central Au+Au collisions indicates a suppression of the total Υ state yield relative to the extrapolation from p+p collision data. The suppression is consistent with measurements made by STAR at RHIC and at higher energies by the CMS experiment at the Large Hadron Collider.

   [All authors]
7. Jet energy measurement and its systematic uncertainty in protonproton collisions at √s = 7 TeV with the ATLAS detector

   Aad G., Alon R., Barak L., Bressler S., Citron Z. H., Duchovni E., Gabizon O., Gross E., Groth-Jensen J., Lellouch D., Levinson L. J., Mikenberg G., Milov A., Milstein D., Roth I., Schaarschmidt J., Silbert O., Smakhtin V., Vitells O. et al. (2015) European Physical Journal C. 75, 1, 17.  Abstract

   The jet energy scale (JES) and its systematic uncertainty are determined for jets measured with the ATLAS detector using protonproton collision data with a centre-ofmass energy of √s = 7 TeV corresponding to an integrated luminosity of 4.7 fb⁻¹. Jets are reconstructed from energy deposits forming topological clusters of calorimeter cells using the anti-k_t algorithm with distance parameters R = 0.4 or R = 0.6, and are calibrated using MC simulations. A residual JES correction is applied to account for differences between data and MC simulations. This correction and its systematic uncertainty are estimated using a combination of in situ techniques exploiting the transverse momentum balance between a jet and a For central jets at lower pT a Z boson, for 20 ≤ p^jet_Tjet_TT, the uncertainty is about 3 %. A consistent JES estimate is found using measurements of the calorimeter response of single hadrons in protonproton collisions and test-beam data, which also provide the estimate for p^jet_T > 1 TeV. The calibration of forward jets is derived from dijet p_T balance measurements. The resulting uncertainty reaches its largest value of 6 % for low-p_T jets at |η| =4.5. Additional JES uncertainties due to specific event topologies, such as close-by jets or selections of event samples with an enhanced content of jets originating from light quarks or gluons, are also discussed. The magnitude of these uncertainties depends on the event sample used in a given physics analysis, but typically amounts to 0.53 %.

   [All authors]