HE-LHC: The High-Energy Large Hadron Collider

The European Physical Journal Special Topics Springer Nature 228:5 (2019) 1109-1382

Authors:

A Abada, M Abbrescia, SS AbdusSalam, I Abdyukhanov, J Abelleira Fernandez, A Abramov, M Aburaia, AO Acar, PR Adzic, P Agrawal, JA Aguilar-Saavedra, JJ Aguilera-Verdugo, M Aiba, I Aichinger, G Aielli, A Akay, A Akhundov, H Aksakal, JL Albacete, S Albergo, A Alekou, M Aleksa, R Aleksan, RM Alemany Fernandez, Y Alexahin, RG Alía, S Alioli, N Alipour Tehrani, BC Allanach, PP Allport, M Altınlı, W Altmannshofer, G Ambrosio, D Amorim, O Amstutz, L Anderlini, A Andreazza, M Andreini, A Andriatis, C Andris, A Andronic, M Angelucci, F Antinori, SA Antipov, M Antonelli, M Antonello, P Antonioli, S Antusch, F Anulli, L Apolinário, G Apollinari, A Apollonio, D Appelö, RB Appleby, A Apyan, A Apyan, A Arbey, A Arbuzov, G Arduini, V Arı, S Arias, N Armesto, R Arnaldi, SA Arsenyev, M Arzeo, S Asai, E Aslanides, RW Aßmann, D Astapovych, M Atanasov, S Atieh, D Attié, B Auchmann, A Audurier, S Aull, S Aumon, S Aune, F Avino, G Avrillaud, G Aydın, A Azatov, G Azuelos, P Azzi, O Azzolini, P Azzurri, N Bacchetta, E Bacchiocchi, H Bachacou, YW Baek, V Baglin, Y Bai, S Baird, MJ Baker, MJ Baldwin, AH Ball, A Ballarino, S Banerjee, DP Barber, D Barducci, P Barjhoux, D Barna, GG Barnaföldi, MJ Barnes, A Barr, J Barranco García, J Barreiro Guimarães da Costa, W Bartmann, V Baryshevsky, E Barzi, SA Bass, A Bastianin, B Baudouy, F Bauer, M Bauer, T Baumgartner, I Bautista-Guzmán, C Bayındır, F Beaudette, F Bedeschi, M Béguin, I Bellafont, L Bellagamba, N Bellegarde, E Belli, E Bellingeri, F Bellini, G Bellomo, S Belomestnykh, G Bencivenni, M Benedikt, G Bernardi, J Bernardi, C Bernet, JM Bernhardt, C Bernini, C Berriaud, A Bertarelli, S Bertolucci, MI Besana, M Besançon, O Beznosov, P Bhat, C Bhat, ME Biagini, J-L Biarrotte, A Bibet Chevalier, ER Bielert, M Biglietti, GM Bilei, B Bilki, C Biscari, F Bishara, OR Blanco-García, FR Blánquez, F Blekman, A Blondel, J Blümlein, T Boccali, R Boels, SA Bogacz, A Bogomyagkov, O Boine-Frankenheim, MJ Boland, S Bologna, O Bolukbasi, M Bomben, S Bondarenko, M Bonvini, E Boos, B Bordini, F Bordry, G Borghello, L Borgonovi, S Borowka, D Bortoletto, D Boscherini, M Boscolo, S Boselli, RR Bosley, F Bossu, C Botta, L Bottura, R Boughezal, D Boutin, G Bovone, I Božović Jelisavić, A Bozbey, C Bozzi, D Bozzini, V Braccini, S Braibant-Giacomelli, J Bramante, P Braun-Munzinger, JA Briffa, D Britzger, SJ Brodsky, JJ Brooke, R Bruce, P Brückman De Renstrom, E Bruna, O Brüning, O Brunner, K Brunner, P Bruzzone, X Buffat, E Bulyak, F Burkart, H Burkhardt, J-P Burnet, F Butin, D Buttazzo, A Butterworth, M Caccia, Y Cai, B Caiffi, V Cairo, O Cakir, R Calaga, S Calatroni, G Calderini, G Calderola, A Caliskan, D Calvet, M Calviani, JM Camalich, P Camarri, M Campanelli, T Camporesi, AC Canbay, A Canepa, E Cantergiani, D Cantore-Cavalli, M Capeans, R Cardarelli, U Cardella, A Cardini, CM Carloni Calame, F Carra, S Carra, A Carvalho, S Casalbuoni, J Casas, M Cascella, P Castelnovo, G Castorina, G Catalano, V Cavasinni, E Cazzato, E Cennini, A Cerri, F Cerutti, J Cervantes, I Chaikovska, J Chakrabortty, M Chala, M Chamizo-Llatas, H Chanal, D Chanal, S Chance, A Chancé, P Charitos, J Charles, TK Charles, S Chattopadhyay, R Chehab, SV Chekanov, N Chen, A Chernoded, V Chetvertkova, L Chevalier, G Chiarelli, G Chiarello, M Chiesa, P Chiggiato, JT Childers, A Chmielińska, A Cholakian, P Chomaz, M Chorowski, W Chou, M Chrzaszcz, E Chyhyrynets, G Cibinetto, AK Ciftci, R Ciftci, R Cimino, M Ciuchini, PJ Clark, Y Coadou, M Cobal, A Coccaro, J Cogan, E Cogneras, F Collamati, C Colldelram, P Collier, J Collot, R Contino, F Conventi, CTA Cook, L Cooley, G Corcella, AS Cornell, GH Corral, H Correia-Rodrigues, F Costanza, P Costa Pinto, F Couderc, J Coupard, N Craig, I Crespo Garrido, A Crivellin, JF Croteau, M Crouch, E Cruz Alaniz, B Curé, J Curti, D Curtin, M Czech, C Dachauer, RT D’Agnolo, M Daibo, A Dainese, B Dalena, A Daljevec, W Dallapiazza, L D’Aloia Schwartzentruber, M Dam, G D’Ambrosio, SP Das, S DasBakshi, W da Silva, GG da Silveira, V D’Auria, S D’Auria, A David, T Davidek, A Deandrea, J de Blas, CJ Debono, S De Curtis, N De Filippis, D de Florian, S Deghaye, SJ de Jong, C Del Bo, V Del Duca, D Delikaris, F Deliot, A Dell’Acqua, L Delle Rose, M Delmastro, E De Lucia, M Demarteau, D Denegri, L Deniau, D Denisov, H Denizli, A Denner, D d’Enterria, G de Rijk, A De Roeck, F Derue, O Deschamps, S Descotes-Genon, PSB Dev, JB de Vivie de Régie, RK Dewanjee, A Di Ciaccio, A Di Cicco, BM Dillon, B Di Micco, P Di Nezza, S Di Vita, A Doblhammer, A Dominjon, M D’Onofrio, F Dordei, A Drago, P Draper, Z Drasal, M Drewes, L Duarte, I Dubovyk, P Duda, A Dudarev, L Dudko, D Duellmann, M Dünser, T du Pree, M Durante, H Duran Yildiz, S Dutta, F Duval, JM Duval, Y Dydyshka, B Dziewit, S Eisenhardt, M Eisterer, T Ekelof, D El Khechen, SA Ellis, J Ellis, JA Ellison, K Elsener, M Elsing, Y Enari, C Englert, H Eriksson, KJ Eskola, LS Esposito, O Etisken, E Etzion, P Fabbricatore, A Falkowski, A Falou, J Faltova, J Fan, L Fanò, A Farilla, R Farinelli, S Farinon, DA Faroughy, SD Fartoukh, A Faus-Golfe, WJ Fawcett, G Felici, L Felsberger, C Ferdeghini, AM Fernandez Navarro, A Fernández-Téllez, J Ferradas Troitino, G Ferrara, R Ferrari, L Ferreira, P Ferreira da Silva, G Ferrera, F Ferro, M Fiascaris, S Fiorendi, C Fiorio, O Fischer, E Fischer, W Flieger, M Florio, D Fonnesu, E Fontanesi, N Foppiani, K Foraz, D Forkel-Wirth, S Forte, M Fouaidy, D Fournier, T Fowler, J Fox, P Francavilla, R Franceschini, S Franchino, E Franco, A Freitas, B Fuks, K Furukawa, SV Furuseth, E Gabrielli, A Gaddi, M Galanti, E Gallo, S Ganjour, J Gao, J Gao, V Garcia Diaz, M García Pérez, L García Tabarés, C Garion, MV Garzelli, I Garzia, SM Gascon-Shotkin, G Gaudio, P Gay, S-F Ge, T Gehrmann, MH Genest, R Gerard, F Gerigk, H Gerwig, P Giacomelli, S Giagu, E Gianfelice-Wendt, F Gianotti, F Giffoni, SS Gilardoni, M Gil Costa, M Giovannetti, M Giovannozzi, P Giubellino, GF Giudice, A Giunta, LK Gladilin, S Glukhov, J Gluza, G Gobbi, B Goddard, F Goertz, T Golling, VP Goncalves, R Gonçalo, LA Gonzalez Gomez, S Gorgi Zadeh, G Gorine, E Gorini, SA Gourlay, L Gouskos, F Grancagnolo, A Grassellino, A Grau, E Graverini, HM Gray, Ma Greco, Mi Greco, J-L Grenard, O Grimm, C Grojean, VA Gromov, JF Grosse-Oetringhaus, A Grudiev, K Grzanka, J Gu, D Guadagnoli, V Guidi, S Guiducci, G Guillermo Canton, YO Günaydin, R Gupta, RS Gupta, J Gutierrez, J Gutleber, C Guyot, V Guzey, C Gwenlan, C Haberstroh, B Hacışahinoğlu, B Haerer, K Hahn, T Hahn, A Hammad, C Han, M Hance, A Hannah, PC Harris, C Hati, S Haug, J Hauptman, V Haurylavets, H-J He, A Hegglin, B Hegner, K Heinemann, S Heinemeyer, C Helsens, A Henriques, A Henriques, P Hernandez, RJ Hernández-Pinto, J Hernandez-Sanchez, T Herzig, I Hiekkanen, W Hillert, T Hoehn, M Hofer, W Höfle, F Holdener, S Holleis, B Holzer, DK Hong, CG Honorato, SC Hopkins, J Hrdinka, F Hug, B Humann, H Humer, T Hurth, A Hutton, G Iacobucci, N Ibarrola, L Iconomidou-Fayard, K Ilyina-Brunner, J Incandela, A Infantino, V Ippolito, M Ishino, R Islam, H Ita, A Ivanovs, S Iwamoto, A Iyer, S Izquierdo Bermudez, S Jadach, DO Jamin, P Janot, P Jarry, A Jeff, P Jenny, E Jensen, M Jensen, X Jiang, JM Jiménez, MA Jones, OR Jones, JM Jowett, S Jung, W Kaabi, M Kado, K Kahle, L Kalinovskaya, J Kalinowski, JF Kamenik, K Kannike, SO Kara, H Karadeniz, V Karaventzas, I Karpov, S Kartal, A Karyukhin, V Kashikhin, J Katharina Behr, U Kaya, J Keintzel, PA Keinz, K Keppel, R Kersevan, K Kershaw, H Khanpour, S Khatibi, M Khatiri Yanehsari, VV Khoze, J Kieseler, A Kilic, A Kilpinen, Y-K Kim, DW Kim, U Klein, M Klein, F Kling, N Klinkenberg, S Klöppel, M Klute, VI Klyukhin, M Knecht, B Kniehl, F Kocak, C Koeberl, AM Kolano, A Kollegger, K Kołodziej, AA Kolomiets, J Komppula, I Koop, P Koppenburg, M Koratzinos, M Kordiaczyńska, M Korjik, O Kortner, P Kostka, W Kotlarski, C Kotnig, T Köttig, AV Kotwal, AD Kovalenko, S Kowalski, J Kozaczuk, GA Kozlov, SS Kozub, AM Krainer, T Kramer, M Krämer, M Krammer, AA Krasnov, F Krauss, K Kravalis, L Kretzschmar, RM Kriske, H Kritscher, P Krkotic, H Kroha, M Kucharczyk, S Kuday, A Kuendig, G Kuhlmann, A Kulesza, M Kumar, M Kumar, A Kusina, S Kuttimalai, M Kuze, T Kwon, F Lackner, M Lackner, E La Francesca, M Laine, G Lamanna, S La Mendola, E Lançon, G Landsberg, P Langacker, C Lange, A Langner, AJ Lankford, JP Lansberg, T Lari, PJ Laycock, P Lebrun, A Lechner, K Lee, S Lee, R Lee, T Lefevre, P Le Guen, T Lehtinen, SB Leith, P Lenzi, E Leogrande, C Leonidopoulos, I Leon-Monzon, G Lerner, O Leroy, T Lesiak, P Lévai, A Leveratto, E Levichev, G Li, S Li, R Li, D Liberati, M Liepe, DA Lissauer, Z Liu, A Lobko, E Locci, E Logothetis Agaliotis, MP Lombardo, AJ Long, C Lorin, R Losito, A Louzguiti, I Low, D Lucchesi, MT Lucchini, A Luciani, M Lueckhof, AJG Lunt, M Luzum, DA Lyubimtsev, M Maggiora, N Magnin, MA Mahmoud, F Mahmoudi, J Maitre, V Makarenko, A Malagoli, J Malclés, L Malgeri, PJ Mallon, F Maltoni, S Malvezzi, OB Malyshev, G Mancinelli, P Mandrik, P Manfrinetti, M Mangano, P Manil, M Mannelli, G Marchiori, F Marhauser, V Mariani, V Marinozzi, S Mariotto, P Marquard, C Marquet, T Marriott-Dodington, R Martin, O Martin, J Martin Camalich, T Martinez, H Martinez Bruzual, MI Martínez-Hernández, DE Martins, S Marzani, D Marzocca, L Marzola, S Masciocchi, I Masina, A Massimiliano, A Massironi, T Masubuchi, VA Matveev, MA Mazzoni, M McCullough, PA McIntosh, P Meade, L Medina, A Meier, J Meignan, B Mele, JG Mendes Saraiva, F Menez, M Mentink, E Meoni, P Meridiani, M Merk, P Mermod, V Mertens, L Mether, E Métral, M Migliorati, A Milanese, C Milardi, G Milhano, BL Militsyn, F Millet, I Minashvili, JV Minervini, LS Miralles, D Mirarchi, S Mishima, DP Missiaen, G Mitselmakher, T Mitshuhashi, J Mnich, M Mohammadi Najafabadi, RN Mohapatra, N Mokhov, JG Molson, R Monge, C Montag, G Montagna, S Monteil, G Montenero, E Montesinos, F Moortgat, N Morange, G Morello, M Moreno Llácer, M Moretti, S Moretti, AK Morley, A Moros, I Morozov, V Morretta, M Morrone, A Mostacci, S Muanza, N Muchnoi, M Mühlegger, M Mulder, M Mulders, B Müller, F Müller, A-S Müller, J Munilla, MJ Murray, Y Muttoni, S Myers, M Mylona, J Nachtman, T Nakamoto, M Nardecchia, G Nardini, P Nason, Z Nergiz, AV Nesterenko, JA Netto, A Nettsträter, C Neubüser, J Neundorf, F Niccoli, O Nicrosini, Y Nie, U Niedermayer, J Niedziela, A Niemi, SA Nikitin, A Nisati, JM No, M Nonis, Y Nosochkov, M Novák, A Novokhatski, JM O’Callaghan, C Ochando, S Ogur, K Ohmi, K Oide, VA Okorokov, Y Okumura, C Oleari, FI Olness, Y Onel, M Ortino, J Osborne, P Osland, T Otto, KY Oyulmaz, A Ozansoy, V Özcan, K Özdemir, CE Pagliarone, HF Pais da Silva, E Palmieri, L Palumbo, A Pampaloni, R-Q Pan, M Panareo, O Panella, G Panico, G Panizzo, AA Pankov, V Pantsyrny, CG Papadopoulos, A Papaefstathiou, Y Papaphilippou, MA Parker, V Parma, M Pasquali, SK Patra, R Patterson, H Paukkunen, F Pauss, S Peggs, J-P Penttinen, G Peón, EE Perepelkin, E Perez, JC Perez, G Perez, F Pérez, E Perez Codina, J Perez Morales, M Perfilov, H Pernegger, M Peruzzi, C Pes, K Peters, S Petracca, F Petriello, L Pezzotti, S Pfeiffer, F Piccinini, T Pieloni, M Pierini, H Pikhartova, G Pikurs, E Pilicer, P Piminov, C Pira, R Pittau, W Płaczek, M Plagge, T Plehn, M-A Pleier, M Płoskoń, M Podeur, H Podlech, T Podzorny, L Poggioli, A Poiron, G Polesello, M Poli Lener, A Polini, J Polinski, SM Polozov, L Ponce, M Pont, L Pontecorvo, T Portaluri, K Potamianos, C Prasse, M Prausa, A Preinerstorfer, E Premat, T Price, M Primavera, F Prino, M Prioli, J Proudfoot, A Provino, T Pugnat, N Pukhaeva, S Puławski, D Pulikowski, G Punzi, M Putti, A Pyarelal, H Quack, M Quispe, A Racioppi, H Rafique, V Raginel, M Raidal, NS Ramírez-Uribe, MJ Ramsey-Musolf, R Rata, P Ratoff, F Ravotti, P Rebello Teles, M Reboud, S Redaelli, E Renner, AE Rentería-Olivo, M Rescigno, J Reuter, A Ribon, AM Ricci, W Riegler, S Riemann, B Riemann, T Riemann, JM Rifflet, RA Rimmer, R Rinaldesi, L Rinolfi, O Rios Rubiras, T Risselada, A Rivetti, L Rivkin, T Rizzo, T Robens, F Robert, AJ Robson, E Rochepault, C Roda, G Rodrigo, M Rodríguez-Cahuantzi, C Rogan, M Roig, S Rojas-Torres, J Rojo, G Rolandi, G Rolando, P Roloff, A Romanenko, A Romanov, F Roncarolo, A Rosado Sanchez, G Rosaz, L Rossi, A Rossi, R Rossmanith, B Rousset, C Royon, X Ruan, I Ruehl, V Ruhlmann-Kleider, R Ruiz, L Rumyantsev, R Ruprecht, AI Ryazanov, A Saba, R Sadykov, D Saez de Jauregui, M Sahin, B Sailer, M Saito, F Sala, GP Salam, J Salfeld-Nebgen, CA Salgado, S Salini, JM Sallese, T Salmi, A Salzburger, OA Sampayo, S Sanfilippo, J Santiago, E Santopinto, R Santoro, A Sanz Ull, X Sarasola, IH Sarpün, M Sauvain, S Savelyeva, R Sawada, GFR Sborlini, A Schaffer, M Schaumann, M Schenk, C Scheuerlein, I Schienbein, K Schlenga, H Schmickler, R Schmidt, D Schoerling, A Schoning, T Schörner-Sadenius, M Schott, D Schulte, P Schwaller, C Schwanenberger, P Schwemling, N Schwerg, L Scibile, A Sciuto, E Scomparin, C Sebastiani, B Seeber, M Segreti, P Selva, M Selvaggi, C Senatore, A Senol, L Serin, M Serluca, N Serra, A Seryi, L Sestini, A Sfyrla, M Shaposhnikov, E Shaposhnikova, BY Sharkov, D Shatilov, J Shelton, V Shiltsev, IP Shipsey, GD Shirkov, A Shivaji, D Shwartz, T Sian, S Sidorov, A Siemko, L Silvestrini, N Simand, F Simon, BK Singh, A Siódmok, Y Sirois, E Sirtori, R Sirvinskaite, B Sitar, T Sjöstrand, P Skands, E Skordis, K Skovpen, M Skrzypek, E Slade, P Slavich, R Slovak, V Smaluk, V Smirnov, W Snoeys, L Soffi, P Sollander, O Solovyanov, HK Soltveit, H Song, P Sopicki, M Sorbi, L Spallino, M Spannowsky, B Spataro, P Sphicas, H Spiesberger, P Spiller, M Spira, T Srivastava, J Stachel, A Stakia, JL Stanyard, E Starchenko, AY Starikov, AM Staśto, M Statera, R Steerenberg, J Steggemann, A Stenvall, F Stivanello, D Stöckinger, LS Stoel, M Stöger-Pollach, B Strauss, M Stuart, G Stupakov, S Su, A Sublet, K Sugita, L Sulak, MK Sullivan, S Sultansoy, T Sumida, K Suzuki, G Sylva, MJ Syphers, A Sznajder, M Taborelli, NA Tahir, M Takeuchi, E Tal Hod, C Tambasco, J Tanaka, K Tang, I Tapan, S Taroni, GF Tartarelli, G Tassielli, L Tavian, TM Taylor, GN Taylor, AM Teixeira, G Tejeda-Muñoz, VI Telnov, R Tenchini, HHJ ten Kate, K Terashi, A Tesi, M Testa, C Tetrel, D Teytelman, J Thaler, A Thamm, S Thomas, MT Tiirakari, V Tikhomirov, D Tikhonov, H Timko, V Tisserand, LM Tkachenko, J Tkaczuk, JP Tock, B Todd, E Todesco, R Tomás Garcia, D Tommasini, G Tonelli, F Toral, T Torims, R Torre, Z Townsend, R Trant, D Treille, L Trentadue, A Tricoli, A Tricomi, W Trischuk, IS Tropin, B Tuchming, AA Tudora, B Turbiarz, I Turk Cakir, M Turri, T Tydecks, J Usovitsch, J Uythoven, R Vaglio, A Valassi, F Valchkova, MA Valdivia Garcia, P Valente, RU Valente, A-M Valente-Feliciano, G Valentino, L Vale Silva, JM Valet, R Valizadeh, JWF Valle, S Vallecorsa, G Vallone, M van Leeuwen, UH van Rienen, L van Riesen-Haupt, M Varasteh, L Vecchi, P Vedrine, G Velev, R Veness, A Ventura, W Venturini Delsolaro, M Verducci, CB Verhaaren, C Vernieri, AP Verweij, O Verwilligen, O Viazlo, A Vicini, G Viehhauser, N Vignaroli, M Vignolo, A Vitrano, I Vivarelli, S Vlachos, M Vogel, DM Vogt, V Völkl, P Volkov, G Volpini, J von Ahnen, G Vorotnikov, GG Voutsinas, V Vysotsky, U Wagner, R Wallny, L-T Wang, R Wang, K Wang, BFL Ward, TP Watson, NK Watson, Z Ws, C Weiland, S Weinzierl, CP Welsch, J Wenninger, M Widorski, UA Wiedemann, H-U Wienands, G Wilkinson, PH Williams, A Winter, A Wohlfahrt, T Wojtoń, D Wollmann, J Womersley, D Woog, X Wu, A Wulzer, MK Yanehsari, G Yang, HJ Yang, W-M Yao, E Yazgan, V Yermolchik, A Yilmaz, A Yilmaz, H-D Yoo, SA Yost, T You, C Young, T-T Yu, F Yu, A Zaborowska, SG Zadeh, M Zahnd, M Zanetti, L Zanotto, L Zawiejski, P Zeiler, M Zerlauth, SM Zernov, G Zevi Dell Porta, Z Zhang, Y Zhang, C Zhang, H Zhang, Z Zhao, Y-M Zhong, J Zhou, D Zhou, P Zhuang, G Zick, F Zimmermann, J Zinn-Justin, L Zivkovic, AV Zlobin, M Zobov, J Zupan, J Zurita

Hearing without seeing: gravitational waves from hot and cold hidden sectors

Journal of High Energy Physics Springer Nature 2019:7 (2019) 44

Authors:

Malcolm Fairbairn, Edward Hardy, Alastair Wickens

Convergence of the Gradient Expansion in Hydrodynamics

Physical Review Letters American Physical Society (APS) 122:25 (2019) 251601

Authors:

Sašo Grozdanov, Pavel K Kovtun, Andrei O Starinets, Petar Tadić

Physics potential of the International Axion Observatory (IAXO)

Journal of Cosmology and Astroparticle Physics IOP Publishing 2019:6 (2019) 47

Authors:

E Armengaud, D Attie, S Basso, P Brun, N Bykovskiy, JM Carmona, JF Castel, S Cebrian, M Cicoli, M Civitani, C Cogollos, Joseph Conlon, D Costa, T Dafni, R Daido, AV Derbin, MA Descalle, K Desch, IS Dratchnev, B Doebrich, A Dudarev, E Ferrer-Ribas, I Fleck, J Galan, G Galanti, L Garrido, D Gascon, L Gastaldo, C Germani, G Ghisellini, M Giannotti, I Giomataris, S Gninenko, N Golubev, R Graciani, IG Irastorza, K Jakovcic, J Kaminski, M Krcmar, C Krieger, B Lakic, T Lasserre, P Laurent, O Limousin, A Lindner, I Lomskaya, B Lubsandorzhiev, G Luzon, MCD Marsh, C Mergalejo

Abstract:

We review the physics potential of a next generation search for solar axions: the International Axion Observatory (IAXO). Endowed with a sensitivity to discover axion-like particles (ALPs) with a coupling to photons as small as gaγ ∼ 10−12 GeV−1 , or to electrons gae ∼10−13, IAXO has the potential to find the QCD axion in the 1 meV∼1 eV mass range where it solves the strong CP problem, can account for the cold dark matter of the Universe and be responsible for the anomalous cooling observed in a number of stellar systems. At the same time, IAXO will have enough sensitivity to detect lower mass axions invoked to explain: 1) the origin of the anomalous “transparency” of the Universe to gamma-rays, 2) the observed soft X-ray excess from galaxy clusters or 3) some inflationary models. In addition, we review string theory axions with parameters accessible by IAXO and discuss their potential role in cosmology as Dark Matter and Dark Radiation as well as their connections to the above mentioned conundrums.

Search for transient optical counterparts to high-energy IceCube neutrinos with Pan-STARRS1

Astronomy and Astrophysics EDP Sciences 626 (2019) A117

Authors:

E Kankare, M Huber, SJ Smartt, K Chambers, KW Smith, O McBrien, T-W Chen, H Flewelling, T Lowe, E Magnier, A Schultz, C Waters, RJ Wainscoat, M Willman, D Wright, D Young, M Ackermann, J Adams, JA Aguilar, M Ahlers, M Ahrens, C Alispach, D Altmann, K Andeen, T Anderson, I Ansseau, G Anton, C Argüelles, J Auffenberg, S Axani, P Backes, H Bagherpour, X Bai, A Barbano, SW Barwick, V Baum, R Bay, JJ Beatty, K-H Becker, JB Tjus, S Benzvi, D Berley, E Bernardini, DZ Besson, G Binder, D Bindig, E Blaufuss, S Blot, C Bohm

Abstract:

In order to identify the sources of the observed diffuse high-energy neutrino flux, it is crucial to discover their electromagnetic counterparts. To increase the sensitivity of detecting counterparts of transient or variable sources by telescopes with a limited field of view, IceCube began releasing alerts for single high-energy (Eν >  60 TeV) neutrino detections with sky localisation regions of order 1° radius in 2016. We used Pan-STARRS1 to follow-up five of these alerts during 2016–2017 to search for any optical transients that may be related to the neutrinos. Typically 10–20 faint (miP1 ≲ 22.5 mag) extragalactic transients are found within the Pan-STARRS1 footprints and are generally consistent with being unrelated field supernovae (SNe) and AGN. We looked for unusual properties of the detected transients, such as temporal coincidence of explosion epoch with the IceCube timestamp, or other peculiar light curve and physical properties. We found only one transient that had properties worthy of a specific follow-up. In the Pan-STARRS1 imaging for IceCube-160427A (probability to be of astrophysical origin of ∼50%), we found a SN PS16cgx, located at 10.0′ from the nominal IceCube direction. Spectroscopic observations of PS16cgx showed that it was an H-poor SN at redshift z = 0.2895 ± 0.0001. The spectra and light curve resemble some high-energy Type Ic SNe, raising the possibility of a jet driven SN with an explosion epoch temporally coincident with the neutrino detection. However, distinguishing Type Ia and Type Ic SNe at this redshift is notoriously difficult. Based on all available data we conclude that the transient is more likely to be a Type Ia with relatively weak Si II absorption and a fairly normal rest-frame r-band light curve. If, as predicted, there is no high-energy neutrino emission from Type Ia SNe, then PS16cgx must be a random coincidence, and unrelated to the IceCube-160427A. We find no other plausible optical transient for any of the five IceCube events observed down to a 5σ limiting magnitude of miP1 ≈ 22 mag, between 1 day and 25 days after detection.