S. Demirci, T. Lappi, and S. Schlichting
Phys. Rev. D 103, 094025 (2021) - Published 21 May, 2021
In this paper, the authors study the origin of eccentricity, or more generally, the azimuthal asymmetry in the initial conditions of small colliding systems, such as the proton nucleus system. Of the contending sources, namely color charge fluctuations and the geometric fluctuation of the so called hot spots in the proton, they conclude that the latter is by far the dominant cause of the asymmetry.
Anthony Ciavarella, Natalie Klco, and Martin J. Savage
Phys. Rev. D 103, 094501 (2021) - Published 4 May, 2021
The authors report the first calculations for an SU(3) gauge theory on a quantum computer, with results for the time evolution. They emphasize how the continuous gauge fields are truncated and represented on quantum hardware and suggest benchmarks that can be used to quantify the performance.
M. S. Abdallah et al. (STAR Collaboration)
Phys. Rev. D 103, L091103 (2021) - Published 26 May, 2021
The authors present the best high-precision measurements of the longitudinal double-spin asymmetry for jet and dijet production in polarized proton collisions, improving on their previous results. The data are sensitive to the gluon helicity distribution and provide new constraints.
M. Ablikim et al. (BESIII Collaboration)
Phys. Rev. D 103, L091101 (2021) - Published 19 May, 2021
M. Ablikim et al. (BESIII Collaboration)
Phys. Rev. D 103, L091102 (2021) - Published 19 May, 2021
M. S. Abdallah et al. (STAR Collaboration)
Phys. Rev. D 103, L091103 (2021) - Published 26 May, 2021
The authors present the best high-precision measurements of the longitudinal double-spin asymmetry for jet and dijet production in polarized proton collisions, improving on their previous results. The data are sensitive to the gluon helicity distribution and provide new constraints.
L. J. Flores et al. ( Theory Group at IF-UNAM, SBC Collaboration)
Phys. Rev. D 103, L091301 (2021) - Published 4 May, 2021
Tomáš Blažek and Peter Maták
Phys. Rev. D 103, L091302 (2021) - Published 26 May, 2021
Rong Wang, Wei Kou, Ya-Ping Xie, and Xurong Chen
Phys. Rev. D 103, L091501 (2021) - Published 11 May, 2021
Arpan Das, Wojciech Florkowski, Radoslaw Ryblewski, and Rajeev Singh
Phys. Rev. D 103, L091502 (2021) - Published 17 May, 2021
Hua-Xing Chen, Wei Chen, and Shi-Lin Zhu
Phys. Rev. D 103, L091503 (2021) - Published 20 May, 2021
J. P. Lees et al. (BABAR Collaboration)
Phys. Rev. D 103, 092001 (2021) - Published 6 May, 2021
V. Sharma, L. Singh, H. T. Wong, M. Agartioglu, J.-W. Chen, M. Deniz, S. Kerman, H. B. Li, C.-P. Liu, K. Saraswat, M. K. Singh, and V. Singh (TEXONO Collaboration)
Phys. Rev. D 103, 092002 (2021) - Published 7 May, 2021
P. Abratenko et al. (MicroBooNE Collaboration)
Phys. Rev. D 103, 092003 (2021) - Published 14 May, 2021
M. Ablikim et al. (BESIII Collaboration)
Phys. Rev. D 103, 092004 (2021) - Published 19 May, 2021
M. Ablikim et al. (BESIII Collaboration)
Phys. Rev. D 103, 092005 (2021) - Published 19 May, 2021
M. Ablikim et al. (BESIII Collaboration)
Phys. Rev. D 103, 092006 (2021) - Published 24 May, 2021
Vinicius Mikuni and Florencia Canelli
Phys. Rev. D 103, 092007 (2021) - Published 24 May, 2021
S. Ajimura et al. (CANDLES Collaboration)
Phys. Rev. D 103, 092008 (2021) - Published 26 May, 2021
J. Adam et al. (STAR Collaboration)
Phys. Rev. D 103, 092009 (2021) - Published 27 May, 2021
Stefan Groote, Mikhail A. Ivanov, Jürgen G. Körner, Valery E. Lyubovitskij, Pietro Santorelli, and Chien-Thang Tran
Phys. Rev. D 103, 093001 (2021) - Published 11 May, 2021
G. López Castro and Néstor Quintero
Phys. Rev. D 103, 093002 (2021) - Published 27 May, 2021
Bingkai Sheng, Yuanyuan Wang, Xinyang Wang, and Lang Yu
Phys. Rev. D 103, 094001 (2021) - Published 7 May, 2021
B. A. Kniehl, G. Kramer, I. Schienbein, and H. Spiesberger
Phys. Rev. D 103, 094002 (2021) - Published 7 May, 2021
Ahmad Jafar Arifi, Daiki Suenaga, and Atsushi Hosaka
Phys. Rev. D 103, 094003 (2021) - Published 10 May, 2021
A. D. Bolognino, F. G. Celiberto, M. Fucilla, D. Yu. Ivanov, and A. Papa
Phys. Rev. D 103, 094004 (2021) - Published 11 May, 2021
Hai Tao Li, Yiannis Makris, and Ivan Vitev
Phys. Rev. D 103, 094005 (2021) - Published 11 May, 2021
Yui Hayashi and Kei-Ichi Kondo
Phys. Rev. D 103, 094006 (2021) - Published 11 May, 2021
DaZhuang He, Xuan Luo, YiLing Xie, and Hao Sun
Phys. Rev. D 103, 094007 (2021) - Published 11 May, 2021
Toru Kojo and Daiki Suenaga
Phys. Rev. D 103, 094008 (2021) - Published 12 May, 2021
Jai Prakash, Manu Kurian, Santosh K. Das, and Vinod Chandra
Phys. Rev. D 103, 094009 (2021) - Published 12 May, 2021
Kiminad A. Mamo and Ismail Zahed
Phys. Rev. D 103, 094010 (2021) - Published 13 May, 2021
Xiao-Hui Chen, Qi-Nan Wang, Wei Chen, and Hua-Xing Chen
Phys. Rev. D 103, 094011 (2021) - Published 13 May, 2021
Renaud Boussarie and Yacine Mehtar-Tani
Phys. Rev. D 103, 094012 (2021) - Published 13 May, 2021
Fei Gao, Joannis Papavassiliou, and Jan M. Pawlowski
Phys. Rev. D 103, 094013 (2021) - Published 14 May, 2021
F. Febres Cordero, M. Kraus, and L. Reina
Phys. Rev. D 103, 094014 (2021) - Published 14 May, 2021
M. N. Chernodub and Victor E. Ambruş
Phys. Rev. D 103, 094015 (2021) - Published 14 May, 2021
Stefano Bolognesi, Kenichi Konishi, and Andrea Luzio
Phys. Rev. D 103, 094016 (2021) - Published 14 May, 2021
Valery E. Lyubovitskij and Ivan Schmidt
Phys. Rev. D 103, 094017 (2021) - Published 14 May, 2021
Vladimir M. Braun, Alexander N. Manashov, Sven-O. Moch, and Matthias Strohmaier
Phys. Rev. D 103, 094018 (2021) - Published 17 May, 2021
P. M. Copeland, Chueng-Ryong Ji, and W. Melnitchouk
Phys. Rev. D 103, 094019 (2021) - Published 17 May, 2021
Xin-Jian Wen, Rui He, and Jun-Bing Liu
Phys. Rev. D 103, 094020 (2021) - Published 17 May, 2021
A. V. Lipatov and M. A. Malyshev
Phys. Rev. D 103, 094021 (2021) - Published 18 May, 2021
Nick Evans and Konstantinos S. Rigatos
Phys. Rev. D 103, 094022 (2021) - Published 18 May, 2021
Adam Freese and Gerald A. Miller
Phys. Rev. D 103, 094023 (2021) - Published 18 May, 2021
Justin M. Gens, Jesse F. Giron, and Richard F. Lebed
Phys. Rev. D 103, 094024 (2021) - Published 19 May, 2021
S. Demirci, T. Lappi, and S. Schlichting
Phys. Rev. D 103, 094025 (2021) - Published 21 May, 2021
In this paper, the authors study the origin of eccentricity, or more generally, the azimuthal asymmetry in the initial conditions of small colliding systems, such as the proton nucleus system. Of the contending sources, namely color charge fluctuations and the geometric fluctuation of the so called hot spots in the proton, they conclude that the latter is by far the dominant cause of the asymmetry.
Heikki Mäntysaari, Kaushik Roy, Farid Salazar, and Björn Schenke
Phys. Rev. D 103, 094026 (2021) - Published 21 May, 2021
B. Z. Kopeliovich, M. Krelina, and J. Nemchik
Phys. Rev. D 103, 094027 (2021) - Published 21 May, 2021
Fabio L. Braghin
Phys. Rev. D 103, 094028 (2021) - Published 24 May, 2021
J. E. Ramírez, Bogar Díaz, and C. Pajares
Phys. Rev. D 103, 094029 (2021) - Published 25 May, 2021
Shen-Song Wan, Gianluca Giuliani, and Marco Ruggieri
Phys. Rev. D 103, 094030 (2021) - Published 25 May, 2021
Neelkamal Mallick, Sushanta Tripathy, Aditya Nath Mishra, Suman Deb, and Raghunath Sahoo
Phys. Rev. D 103, 094031 (2021) - Published 25 May, 2021
Rubén Flores-Mendieta, Carlos Isaac García, and Johann Hernández
Phys. Rev. D 103, 094032 (2021) - Published 26 May, 2021
K. Azizi, Y. Sarac, and H. Sundu
Phys. Rev. D 103, 094033 (2021) - Published 26 May, 2021
Rajeev Singh, Masoud Shokri, and Radoslaw Ryblewski
Phys. Rev. D 103, 094034 (2021) - Published 26 May, 2021
Marcela Peláez, Urko Reinosa, Julien Serreau, Matthieu Tissier, and Nicolás Wschebor
Phys. Rev. D 103, 094035 (2021) - Published 26 May, 2021
Yu Zhang, Ai-Chao Wang, Neng-Chang Wei, and Fei Huang
Phys. Rev. D 103, 094036 (2021) - Published 26 May, 2021
Li-Qun Su, Chao Shi, Yong-Feng Huang, Yan Yan, Cheng-Ming Li, and Hongshi Zong
Phys. Rev. D 103, 094037 (2021) - Published 27 May, 2021
Pan-Pan Shi, Fei Huang, and Wen-Ling Wang
Phys. Rev. D 103, 094038 (2021) - Published 27 May, 2021
Anthony Ciavarella, Natalie Klco, and Martin J. Savage
Phys. Rev. D 103, 094501 (2021) - Published 4 May, 2021
The authors report the first calculations for an SU(3) gauge theory on a quantum computer, with results for the time evolution. They emphasize how the continuous gauge fields are truncated and represented on quantum hardware and suggest benchmarks that can be used to quantify the performance.
Tomoya Hayata and Yoshimasa Hidaka
Phys. Rev. D 103, 094502 (2021) - Published 10 May, 2021
Wei Sun, Ying Chen, Peng Sun, and Yi-Bo Yang (QCD Collaboration)
Phys. Rev. D 103, 094503 (2021) - Published 10 May, 2021
Xiang Gao, Kyle Lee, Swagato Mukherjee, Charles Shugert, and Yong Zhao
Phys. Rev. D 103, 094504 (2021) - Published 11 May, 2021
Jan M. Pawlowski, Manuel Scherzer, Christian Schmidt, Felix P. G. Ziegler, and Felix Ziesché
Phys. Rev. D 103, 094505 (2021) - Published 12 May, 2021
W. G. Parrott, C. Bouchard, C. T. H. Davies, and D. Hatton (HPQCD Collaboration)
Phys. Rev. D 103, 094506 (2021) - Published 13 May, 2021
Richard C. Brower, Cameron V. Cogburn, A. Liam Fitzpatrick, Dean Howarth, and Chung-I Tan
Phys. Rev. D 103, 094507 (2021) - Published 14 May, 2021
Giorgio Silvi, Srijit Paul, Constantia Alexandrou, Stefan Krieg, Luka Leskovec, Stefan Meinel, John Negele, Marcus Petschlies, Andrew Pochinsky, Gumaro Rendon, Sergey Syritsyn, and Antonino Todaro
Phys. Rev. D 103, 094508 (2021) - Published 14 May, 2021
M. Costa, I. Karpasitis, T. Pafitis, G. Panagopoulos, H. Panagopoulos, A. Skouroupathis, and G. Spanoudes
Phys. Rev. D 103, 094509 (2021) - Published 14 May, 2021
Xiang Gao, Nikhil Karthik, Swagato Mukherjee, Peter Petreczky, Sergey Syritsyn, and Yong Zhao
Phys. Rev. D 103, 094510 (2021) - Published 17 May, 2021
G. S. Bali, S. Bürger, S. Collins, M. Göckeler, M. Gruber, S. Piemonte, A. Schäfer, A. Sternbeck, and P. Wein (RQCD Collaboration)
Phys. Rev. D 103, 094511 (2021) - Published 19 May, 2021
Constantia Alexandrou, Krzysztof Cichy, Martha Constantinou, Jeremy R. Green, Kyriakos Hadjiyiannakou, Karl Jansen, Floriano Manigrasso, Aurora Scapellato, and Fernanda Steffens
Phys. Rev. D 103, 094512 (2021) - Published 18 May, 2021
Thomas DeGrand
Phys. Rev. D 103, 094513 (2021) - Published 24 May, 2021
Rajamani Narayanan
Phys. Rev. D 103, 094514 (2021) - Published 24 May, 2021
V. V. Braguta, A. Yu. Kotov, D. D. Kuznedelev, and A. A. Roenko
Phys. Rev. D 103, 094515 (2021) - Published 24 May, 2021
Stefan Meinel and Gumaro Rendon
Phys. Rev. D 103, 094516 (2021) - Published 24 May, 2021
William Detmold, Gurtej Kanwar, Henry Lamm, Michael L. Wagman, and Neill C. Warrington
Phys. Rev. D 103, 094517 (2021) - Published 24 May, 2021
Yan Li, Jia-Jun Wu, Derek B. Leinweber, and Anthony W. Thomas
Phys. Rev. D 103, 094518 (2021) - Published 24 May, 2021
Lee C. Loveridge, Orlando Oliveira, and Paulo J. Silva
Phys. Rev. D 103, 094519 (2021) - Published 26 May, 2021
Peng Guo and Vladimir Gasparian
Phys. Rev. D 103, 094520 (2021) - Published 27 May, 2021
Raúl A. Briceño and Christopher J. Monahan
Phys. Rev. D 103, 094521 (2021) - Published 27 May, 2021
D. Djukanovic, T. Harris, G. von Hippel, P. M. Junnarkar, H. B. Meyer, D. Mohler, K. Ottnad, T. Schulz, J. Wilhelm, and H. Wittig
Phys. Rev. D 103, 094522 (2021) - Published 28 May, 2021
Andrés Flórez, Alfredo Gurrola, Will Johns, Paul Sheldon, Elijah Sheridan, Kuver Sinha, and Brandon Soubasis
Phys. Rev. D 103, 095001 (2021) - Published 6 May, 2021
Kevin J. Kelly, Soubhik Kumar, and Zhen Liu
Phys. Rev. D 103, 095002 (2021) - Published 6 May, 2021
Xue-Min Jiang, Yi-Lei Tang, Zhao-Huan Yu, and Hong-Hao Zhang
Phys. Rev. D 103, 095003 (2021) - Published 6 May, 2021
Oleg G. Kharlanov and Pavel I. Shustov
Phys. Rev. D 103, 095004 (2021) - Published 7 May, 2021
Guo-yuan Huang, Farinaldo S. Queiroz, and Werner Rodejohann
Phys. Rev. D 103, 095005 (2021) - Published 7 May, 2021
Alexander Belyaev, Stefan Prestel, Felipe Rojas-Abatte, and Jose Zurita
Phys. Rev. D 103, 095006 (2021) - Published 10 May, 2021
N. Rajeev, Niladribihari Sahoo, and Rupak Dutta
Phys. Rev. D 103, 095007 (2021) - Published 12 May, 2021
R. Sekhar Chivukula, Pawin Ittisamai, James Osborne, and Elizabeth H. Simmons
Phys. Rev. D 103, 095008 (2021) - Published 12 May, 2021
Céline Degrande and Matteo Maltoni
Phys. Rev. D 103, 095009 (2021) - Published 12 May, 2021
Ameen Ismail, Ben Keeshan, Heather E. Logan, and Yongcheng Wu
Phys. Rev. D 103, 095010 (2021) - Published 12 May, 2021
P. Ko, Takaaki Nomura, and Hiroshi Okada
Phys. Rev. D 103, 095011 (2021) - Published 18 May, 2021
Joshua Berger, Yanou Cui, Mathew Graham, Lina Necib, Gianluca Petrillo, Dane Stocks, Yun-Tse Tsai, and Yue Zhao
Phys. Rev. D 103, 095012 (2021) - Published 17 May, 2021
Chang-Yuan Yao, Xiang-Gan Liu, and Gui-Jun Ding
Phys. Rev. D 103, 095013 (2021) - Published 17 May, 2021
Linda M. Carpenter, Humberto Gilmer, and Junichiro Kawamura
Phys. Rev. D 103, 095014 (2021) - Published 17 May, 2021
James B. Dent, Bhaskar Dutta, Jayden L. Newstead, Ian M. Shoemaker, and Natalia Tapia Arellano
Phys. Rev. D 103, 095015 (2021) - Published 18 May, 2021
Phung Van Dong, Cao H. Nam, and Duong Van Loi
Phys. Rev. D 103, 095016 (2021) - Published 18 May, 2021
Taisuke Katayose, Shigeki Matsumoto, and Satoshi Shirai
Phys. Rev. D 103, 095017 (2021) - Published 18 May, 2021
Manoranjan Dutta, Satyabrata Mahapatra, Debasish Borah, and Narendra Sahu
Phys. Rev. D 103, 095018 (2021) - Published 19 May, 2021
Masha Baryakhtar, Marios Galanis, Robert Lasenby, and Olivier Simon
Phys. Rev. D 103, 095019 (2021) - Published 19 May, 2021
T. Hurth, F. Mahmoudi, and S. Neshatpour
Phys. Rev. D 103, 095020 (2021) - Published 19 May, 2021
G. Lazarides and Q. Shafi
Phys. Rev. D 103, 095021 (2021) - Published 20 May, 2021
Hiroyuki Ishida, Shinya Matsuzaki, and Yoshihiro Shigekami
Phys. Rev. D 103, 095022 (2021) - Published 20 May, 2021
J. A. Aguilar-Saavedra, J. M. Cano, and J. M. No
Phys. Rev. D 103, 095023 (2021) - Published 24 May, 2021
R. Sekhar Chivukula, Dennis Foren, Kirtimaan A. Mohan, Dipan Sengupta, and Elizabeth H. Simmons
Phys. Rev. D 103, 095024 (2021) - Published 24 May, 2021
Dong Hu, Hao-Ran Jiang, Hao-Lin Li, Ming-Lei Xiao, and Jiang-Hao Yu
Phys. Rev. D 103, 095025 (2021) - Published 24 May, 2021
M. Fabbrichesi, C. M. Nieto, A. Tonero, and A. Ugolotti
Phys. Rev. D 103, 095026 (2021) - Published 24 May, 2021
Shao-Feng Ge, Gang Li, Pedro Pasquini, and Michael J. Ramsey-Musolf
Phys. Rev. D 103, 095027 (2021) - Published 26 May, 2021
Diptimoy Ghosh and Divya Sachdeva
Phys. Rev. D 103, 095028 (2021) - Published 26 May, 2021
João A. A. S. Reis and Marco Schreck
Phys. Rev. D 103, 095029 (2021) - Published 26 May, 2021
Wenhai Xie, R. Benbrik, Abdeljalil Habjia, Souad Taj, Bin Gong, and Qi-Shu Yan
Phys. Rev. D 103, 095030 (2021) - Published 26 May, 2021
N. Darvishi and M. R. Masouminia
Phys. Rev. D 103, 095031 (2021) - Published 27 May, 2021
Nicolás Bernal, Julián Calle, and Diego Restrepo
Phys. Rev. D 103, 095032 (2021) - Published 27 May, 2021
Xunyu Liang, Egor Peshkov, Ludovic Van Waerbeke, and Ariel Zhitnitsky
Phys. Rev. D 103, 096001 (2021) - Published 3 May, 2021
A. Golub, S. Villalba-Chávez, and C. Müller
Phys. Rev. D 103, 096002 (2021) - Published 6 May, 2021
S. V. Mikhailov, A. V. Pimikov, and N. G. Stefanis
Phys. Rev. D 103, 096003 (2021) - Published 7 May, 2021
Kazuo Fujikawa and Koichiro Umetsu
Phys. Rev. D 103, 096004 (2021) - Published 7 May, 2021
Rabah Abdul Khalek, Jacob J. Ethier, Emanuele R. Nocera, and Juan Rojo
Phys. Rev. D 103, 096005 (2021) - Published 11 May, 2021
Qi Huang, Jun-Zhang Wang, Rong-Gang Ping, and Xiang Liu
Phys. Rev. D 103, 096006 (2021) - Published 10 May, 2021
G. L. Klimchitskaya and V. M. Mostepanenko
Phys. Rev. D 103, 096007 (2021) - Published 11 May, 2021
B. Ananthanarayan, Sumit Banik, Samuel Friot, and Shayan Ghosh
Phys. Rev. D 103, 096008 (2021) - Published 13 May, 2021
Anisha, Upalaparna Banerjee, Joydeep Chakrabortty, Christoph Englert, and Michael Spannowsky
Phys. Rev. D 103, 096009 (2021) - Published 12 May, 2021
Yuxun Guo, Xiangdong Ji, and Yizhuang Liu
Phys. Rev. D 103, 096010 (2021) - Published 14 May, 2021
Werner Bernreuther, Long Chen, and Otto Nachtmann
Phys. Rev. D 103, 096011 (2021) - Published 14 May, 2021
Francesco Pegoraro and Sergei V. Bulanov
Phys. Rev. D 103, 096012 (2021) - Published 14 May, 2021
Seong Youl Choi and Jae Hoon Jeong
Phys. Rev. D 103, 096013 (2021) - Published 14 May, 2021
Borut Bajc, Adrián Lugo, and Francesco Sannino
Phys. Rev. D 103, 096014 (2021) - Published 17 May, 2021
Snigdha Ghosh and Sabyasachi Ghosh
Phys. Rev. D 103, 096015 (2021) - Published 18 May, 2021
Jian Chai, Shan Cheng, and Wen-Fei Wang
Phys. Rev. D 103, 096016 (2021) - Published 18 May, 2021
E. Gotsman, Yu. P. Ivanov, and E. Levin
Phys. Rev. D 103, 096017 (2021) - Published 19 May, 2021
Aiden B. Sheckler and Gerald A. Miller
Phys. Rev. D 103, 096018 (2021) - Published 19 May, 2021
F. C. E. Lima, A. Yu. Petrov, and C. A. S. Almeida
Phys. Rev. D 103, 096019 (2021) - Published 19 May, 2021
Hassan Manshouri, Ahmad Hoseinpour, and Moslem Zarei
Phys. Rev. D 103, 096020 (2021) - Published 21 May, 2021
Nilanjan Chaudhuri, Snigdha Ghosh, Sourav Sarkar, and Pradip Roy
Phys. Rev. D 103, 096021 (2021) - Published 24 May, 2021
Cristina Manuel and Juan M. Torres-Rincon
Phys. Rev. D 103, 096022 (2021) - Published 26 May, 2021
Gonzalo Barriga, Fabrizio Canfora, Matías Torres, and Aldo Vera
Phys. Rev. D 103, 096023 (2021) - Published 24 May, 2021
Céline Degrande, Gauthier Durieux, Fabio Maltoni, Ken Mimasu, Eleni Vryonidou, and Cen Zhang
Phys. Rev. D 103, 096024 (2021) - Published 24 May, 2021
J. Ablinger, J. Blümlein, and C. Schneider
Phys. Rev. D 103, 096025 (2021) - Published 25 May, 2021
M. V. Bondarenco
Phys. Rev. D 103, 096026 (2021) - Published 26 May, 2021
Shahriyar Jafarzade, Adrian Koenigstein, and Francesco Giacosa
Phys. Rev. D 103, 096027 (2021) - Published 28 May, 2021
Laurence J. Cooper, Christine T. H. Davies, Judd Harrison, Javad Komijani, and Matthew Wingate (HPQCD Collaboration)
Phys. Rev. D 103, 099901 (2021) - Published 13 May, 2021
Xuan Chen, Gang Li, and Xia Wan
Phys. Rev. D 103, 099902 (2021) - Published 19 May, 2021
J. Yan, S. Watanuki, K. Fujii, A. Ishikawa, D. Jeans, J. Strube, J. Tian, and H. Yamamoto
Phys. Rev. D 103, 099903 (2021) - Published 20 May, 2021