- Main
Coherent diffractive photoproduction of $ρ^{0}$ mesons on gold nuclei at RHIC
- Author(s): Collaboration, STAR
- Adamczyk, L
- Adkins, JK
- Agakishiev, G
- Aggarwal, MM
- Ahammed, Z
- Ajitanand, NN
- Alekseev, I
- Anderson, DM
- Aoyama, R
- Aparin, A
- Arkhipkin, D
- Aschenauer, EC
- Ashraf, MU
- Attri, A
- Averichev, GS
- Bai, X
- Bairathi, V
- Behera, A
- Bellwied, R
- Bhasin, A
- Bhati, AK
- Bhattarai, P
- Bielcik, J
- Bielcikova, J
- Bland, LC
- Bordyuzhin, IG
- Bouchet, J
- Brandenburg, JD
- Brandin, AV
- Brown, D
- Bunzarov, I
- Butterworth, J
- Caines, H
- Sánchez, M Calderón de la Barca
- Campbell, JM
- Cebra, D
- Chakaberia, I
- Chaloupka, P
- Chang, Z
- Chankova-Bunzarova, N
- Chatterjee, A
- Chattopadhyay, S
- Chen, X
- Chen, X
- Chen, JH
- Cheng, J
- Cherney, M
- Christie, W
- Contin, G
- Crawford, HJ
- Das, S
- Silva, LC De
- Debbe, RR
- Dedovich, TG
- Deng, J
- Derevschikov, AA
- Didenko, L
- Dilks, C
- Dong, X
- Drachenberg, JL
- Draper, JE
- Dunkelberger, LE
- Dunlop, JC
- Efimov, LG
- Elsey, N
- Engelage, J
- Eppley, G
- Esha, R
- Esumi, S
- Evdokimov, O
- Ewigleben, J
- Eyser, O
- Fatemi, R
- Fazio, S
- Federic, P
- Federicova, P
- Fedorisin, J
- Feng, Z
- Filip, P
- Finch, E
- Fisyak, Y
- Flores, CE
- Fujita, J
- Fulek, L
- Gagliardi, CA
- Garand, D
- Geurts, F
- Gibson, A
- Girard, M
- Grosnick, D
- Gunarathne, DS
- Guo, Y
- Gupta, A
- Gupta, S
- Guryn, W
- Hamad, AI
- Hamed, A
- Harlenderova, A
- Harris, JW
- He, L
- Heppelmann, S
- Heppelmann, S
- Hirsch, A
- Hoffmann, GW
- Horvat, S
- Huang, B
- Huang, T
- Huang, HZ
- Huang, X
- Humanic, TJ
- Huo, P
- Igo, G
- Jacobs, WW
- Jentsch, A
- Jia, J
- Jiang, K
- Jowzaee, S
- Judd, EG
- Kabana, S
- Kalinkin, D
- Kang, K
- Kauder, K
- Ke, HW
- Keane, D
- Kechechyan, A
- Khan, Z
- Kikoła, DP
- Kisel, I
- Kisiel, A
- Klein, SR
- Kochenda, L
- Kocmanek, M
- Kollegger, T
- Kosarzewski, LK
- Kraishan, AF
- Kravtsov, P
- Krueger, K
- Kulathunga, N
- Kumar, L
- Kvapil, J
- Kwasizur, JH
- Lacey, R
- Landgraf, JM
- Landry, KD
- Lauret, J
- Lebedev, A
- Lednicky, R
- Lee, JH
- Li, W
- Li, X
- Li, C
- Li, Y
- Lidrych, J
- Lin, T
- Lisa, MA
- Liu, Y
- Liu, F
- Liu, H
- Liu, P
- Ljubicic, T
- Llope, WJ
- Lomnitz, M
- Longacre, RS
- Luo, S
- Luo, X
- Ma, GL
- Ma, YG
- Ma, L
- Ma, R
- Magdy, N
- Majka, R
- Mallick, D
- Margetis, S
- Markert, C
- Matis, HS
- Meehan, K
- Mei, JC
- Miller, ZW
- Minaev, NG
- Mioduszewski, S
- Mishra, D
- Mizuno, S
- Mohanty, B
- Mondal, MM
- Morozov, DA
- Mustafa, MK
- Nasim, Md
- Nayak, TK
- Nelson, JM
- Nie, M
- Nigmatkulov, G
- Niida, T
- Nogach, LV
- Nonaka, T
- Nurushev, SB
- Odyniec, G
- Ogawa, A
- Oh, K
- Okorokov, VA
- Jr, D Olvitt
- Page, BS
- Pak, R
- Pandit, Y
- Panebratsev, Y
- Pawlik, B
- Pei, H
- Perkins, C
- Pile, P
- Pluta, J
- Poniatowska, K
- Porter, J
- Posik, M
- Poskanzer, AM
- Pruthi, NK
- Przybycien, M
- Putschke, J
- Qiu, H
- Quintero, A
- Ramachandran, S
- Ray, RL
- Reed, R
- Rehbein, MJ
- Ritter, HG
- Roberts, JB
- Rogachevskiy, OV
- Romero, JL
- Roth, JD
- Ruan, L
- Rusnak, J
- Rusnakova, O
- Sahoo, NR
- Sahu, PK
- Salur, S
- Sandweiss, J
- Saur, M
- Schambach, J
- Schmah, AM
- Schmidke, WB
- Schmitz, N
- Schweid, BR
- Seger, J
- Sergeeva, M
- Seyboth, P
- Shah, N
- Shahaliev, E
- Shanmuganathan, PV
- Shao, M
- Sharma, A
- Sharma, MK
- Shen, WQ
- Shi, Z
- Shi, SS
- Shou, QY
- Sichtermann, EP
- Sikora, R
- Simko, M
- Singha, S
- Skoby, MJ
- Smirnov, N
- Smirnov, D
- Solyst, W
- Song, L
- Sorensen, P
- Spinka, HM
- Srivastava, B
- Stanislaus, TDS
- Strikhanov, M
- Stringfellow, B
- Sugiura, T
- Sumbera, M
- Summa, B
- Sun, Y
- Sun, XM
- Sun, X
- Surrow, B
- Svirida, DN
- Tang, AH
- Tang, Z
- Taranenko, A
- Tarnowsky, T
- Tawfik, A
- Thäder, J
- Thomas, JH
- Timmins, AR
- Tlusty, D
- Todoroki, T
- Tokarev, M
- Trentalange, S
- Tribble, RE
- Tribedy, P
- Tripathy, SK
- Trzeciak, BA
- Tsai, OD
- Ullrich, T
- Underwood, DG
- Upsal, I
- Buren, G Van
- Nieuwenhuizen, G van
- Vasiliev, AN
- Videbæk, F
- Vokal, S
- Voloshin, SA
- Vossen, A
- Wang, G
- Wang, Y
- Wang, F
- Wang, Y
- Webb, JC
- Webb, G
- Wen, L
- Westfall, GD
- Wieman, H
- Wissink, SW
- Witt, R
- Wu, Y
- Xiao, ZG
- Xie, W
- Xie, G
- Xu, J
- Xu, N
- Xu, QH
- Xu, YF
- Xu, Z
- Yang, Y
- Yang, Q
- Yang, C
- Yang, S
- Ye, Z
- Ye, Z
- Yi, L
- Yip, K
- Yoo, I-K
- Yu, N
- Zbroszczyk, H
- Zha, W
- Zhang, Z
- Zhang, XP
- Zhang, JB
- Zhang, S
- Zhang, J
- Zhang, Y
- Zhang, J
- Zhang, S
- Zhao, J
- Zhong, C
- Zhou, L
- Zhou, C
- Zhu, X
- Zhu, Z
- Zyzak, M
- et al.
Published Web Location
https://doi.org/10.1103/PhysRevC.96.054904Abstract
The STAR Collaboration reports on the photoproduction of $\pi^+\pi^-$ pairs in gold-gold collisions at a center-of-mass energy of 200 GeV/nucleon-pair. These pion pairs are produced when a nearly-real photon emitted by one ion scatters from the other ion. We fit the $\pi^+\pi^-$ invariant mass spectrum with a combination of $\rho$ and $\omega$ resonances and a direct $\pi^+\pi^-$ continuum. This is the first observation of the $\omega$ in ultra-peripheral collisions, and the first measurement of $\rho-\omega$ interference at energies where photoproduction is dominated by Pomeron exchange. The $\omega$ amplitude is consistent with the measured $\gamma p\rightarrow \omega p$ cross section, a classical Glauber calculation and the $\omega\rightarrow\pi^+\pi^-$ branching ratio. The $\omega$ phase angle is similar to that observed at much lower energies, showing that the $\rho-\omega$ phase difference does not depend significantly on photon energy. The $\rho^0$ differential cross section $d\sigma/dt$ exhibits a clear diffraction pattern, compatible with scattering from a gold nucleus, with 2 minima visible. The positions of the diffractive minima agree better with the predictions of a quantum Glauber calculation that does not include nuclear shadowing than with a calculation that does include shadowing.