María Teresa Núñez Pardo de Vera, Mikael Berggren, Jenny List
The lighter chargino, $\widetildeχ_1^{\pm}$, is a prime candidate to be the next-to-lightest SUSY particle (the NLSP). Several analyses of $\widetildeχ_1^{\pm}$ pair-production at the ILC, at specific model-points, have been performed, showing that detection and property-determination is possible, even for very difficult cases. However, no recent studies have evaluated the reach of the ILC to detect $\widetildeχ_1^{\pm}$ pair production in general. In this study, cross sections for $\widetildeχ_1^{\pm}$ pair production at the ILC were evaluated within a wide range of parameters. The aim was to determine the conditions for the lowest cross sections and compare these worst-case values with an estimation of the cross section limit for the observation of the lightest charginos at the ILC. The estimated limits were extrapolated from the studies performed at LEP, which can also be regarded as a worst-case scenario, since the tremendous advances in detector and accelerator technologies are disregarded
María Teresa Núñez Pardo de Vera
Data from the LHC at 7, 8, and 13 TeV have so far yielded no evidence for new particles beyond the 125 GeV Higgs boson; in particular, there have been no signs of SUSY. However, the complementary nature of physics with $e^+e^-$ collisions still offers many interesting scenarios in which SUSY can be discovered at the ILC. These scenarios take advantage of the capability of $e^+e^-$ collisions to observe events with missing four-momentum -- a signature not available at hadron colliders, where only transverse imbalance is observable. Due to low backgrounds and trigger-less operation, detectors at $e^+e^-$ colliders can observe events with much less visible energy than what is possible at hadron colliders. In this contribution, we will present detailed simulation studies done with the ILD concept at the ILC. These studies include simulation of the full SM background, as well as realistic accelerator conditions. We will show results both on expected discovery and exclusion reaches for the most challenging SUSY channels, such as higgsinos or winos at low mass differences. Evaluations of precision of model-parameter measurements, in case of discovery, will also be given. We also report on how such measurements can be used to put constraints on parts of the sparticle-spectrum beyond direct reach, and to discriminate between different models of SUSY breaking at high scales.
María Teresa Núñez Pardo de Vera
Although the LHC experiments have searched for and excluded many proposed new particles up to masses close to 1 TeV, there are many scenarios that are difficult to address at a hadron collider. This talk will review a number of these scenarios and present the expectations for searches at an electron-positron collider such as the International Linear Collider. The cases discussed include SUSY in strongly or moderately compressed models, heavy neutrinos, heavy vector bosons coupling to the s-channel in $e^+e^-$ annihilation, and new scalars.
Alexander Aryshev, Ties Behnke, Mikael Berggren, James Brau, Nathaniel Craig, Ayres Freitas, Frank Gaede, Spencer Gessner, Stefania Gori, Christophe Grojean, Sven Heinemeyer, Daniel Jeans, Katja Kruger, Benno List, Jenny List, Zhen Liu, Shinichiro Michizono, David W. Miller, Ian Moult, Hitoshi Murayama, Tatsuya Nakada, Emilio Nanni, Mihoko Nojiri, Hasan Padamsee, Maxim Perelstein, Michael E. Peskin, Roman Poeschl, Sam Posen, Aidan Robson, Jan Strube, Taikan Suehara, Junping Tian, Maxim Titov, Marcel Vos, Andrew White, Graham Wilson, Kaoru Yokoya, Aleksander Filip Zarnecki, Ichiro Adachi, Kaustubh Agashe, Tatjana Agatonovic Jovin, Hiroaki Aihara, Wolfgang Altmannshofer, Daniele Alves, Justin Anguiano, Ken-Ichi Aoki, Masato Aoki, Toshihiro Aoki, Yumi Aoki, Yasuo Arai, Hayato Araki, Haruka Asada, Kento Asai, Shoji Asai, David Attie, Howard Baer, Jonathan Bagger, Yang Bai, Ian Bailey, Ricardo Barrue, Rainer Bartoldus, Emanuela Barzi, Matthew Basso, Lothar Bauerdick, Sebastian Baum, Alain Bellerive, Sergey Belomestnykh, Jorge Berenguer Antequera, Jakob Beyer, Pushpalatha Bhat, Burak Bilki, Kevin Black, Kenneth Bloom, Geoffrey Bodwin, Veronique Boisvert, Fatma Boran, Vincent Boudry, Radja Boughezal, Antonio Boveia, Ivanka Bozovic-Jelisavcic, Jean-Claude Brient, Stanley Brodsky, Laurent Brunetti, Karsten Buesser, Eugene Bulyak, Philip N. Burrows, Graeme C. Burt, Yunhai Cai, Valentina Cairo, Anadi Canepa, Francesco Giovanni Celiberto, Enrico Cenni, Zackaria Chacko, Iryna Chaikovska, Mattia Checchin, Lisong Chen, Thomas Y. Chen, Hsin Chia Cheng, Gi-Chol Cho, Brajesh Choudhary, Jim Clarke, James Cline, Raymond Co, Timothy Cohen, Paul Colas, Chris Damerell, Arindam Das, Sridhara Dasu, Sally Dawson, Jorge de Blas, Carlos Henrique de Lima, Aldo Deandrea, Klaus Dehmelt, Jean Delayen, Carlos Henrique de Lima, Marcel Demarteau, Dmitri Denisov, Radovan Dermisek, Angel Dieguez, Takeshi Dohmae, Jens Dopke, Katharina Dort, Yong Du, Bohdan Dudar, Bhaskar Dutta, Juhi Dutta, Ulrich Einhaus, Eckhard Elsen, Motoi Endo, Grigory Eremeev, Engin Eren, Jens Erler, Eric Esarey, Lisa Everett, Angeles Faus Golfe, Marcos Fernandez Garcia, Brian Foster, Nicolas Fourches, Mary-Cruz Fouz, Keisuke Fujii, Junpei Fujimoto, Esteban Fullan Torregrosa, Kazuro Furukawa, Takahiro Fusayasu, Juan Fuster, Serguei Ganjour, Yuanning Gao, Naveen Gaur, Rongli Geng, Howard Georgi, Tony Gherghetta, Joel Goldstein, Dorival Goncalves, Julia Gonski, Tomas Gonzalo, Takeyoshi Goto, Toru Goto, Norman Graf, Joseph Grames, Paul Grannis, Lindsey Gray, Alexander Grohsjean, Jiayin Gu, Yalcin Guler, Phillip Gutierrez, Junji Haba, Howard Haber, John Hallford, Koichi Hamaguchi, Tao Han, Kazuhiko Hara, Daisuke Harada, Koji Hashimoto, Katsuya Hashino, Masahito Hayashi, Gudrun Heinrich, Keisho Hidaka, Takeo Higuchi, Fujio Hinode, Zenro Hioki, Minoru Hirose, Nagisa Hiroshima, Junji Hisano, Wolfgang Hollik, Samuel Homiller, Sungwoo Hong, Anson Hook, Yasuyuki Horii, Hiroki Hoshina, Ivana Hristova, Katri Huitu, Yoshifumi Hyakutake, Toru Iijima, Katsumasa Ikematsu, Anton Ilderton, Kenji Inami, Adrian Irles, Akimasa Ishikawa, Koji Ishiwata, Hayato Ito, Igor Ivanov, Sho Iwamoto, Toshiyuki Iwamoto, Masako Iwasaki, Yoshihisa Iwashita, Haoyi Jia, Fabricio Jimenez Morales, Prakash Joshi, Sunghoon Jung, Goran Kacarevic, Michael Kagan, Mitsuru Kakizaki, Jan Kalinowski, Jochen Kaminski, Kazuyuki Kanaya, Shinya Kanemura, Hayato Kanno, Yuya Kano, Shigeru Kashiwagi, Yukihiro Kato, Nanami Kawada, Shin-ichi Kawada, Kiyotomo Kawagoe, Valery Khoze, Hiromichi Kichimi, Doojin Kim, Teppei Kitahara, Ryuichiro Kitano, Jan Klamka, Sachio Komamiya, K. C. Kong, Taro Konomi, Katsushige Kotera, Emi Kou, Ilya Kravchenko, Kiyoshi Kubo, Takayuki Kubo, Takuya Kumaoka, Ashish Kumar, Nilanjana Kumar, Jonas Kunath, Saumyen Kundu, Hiroshi Kunitomo, Masakazu Kurata, Masao Kuriki, Alexander Kusenko, Theodota Lagouri, Andrew J. Lankford, Gordana Lastovicka-Medin, Francois Le Diberder, Claire Lee, Matthias Liepe, Jacob Linacre, Zachary Liptak, Shivani Lomte, Ian Low, Yang Ma, Hani Maalouf, David MacFarlane, Brendon Madison, Thomas Madlener, Tomohito Maeda, Paul Malek, Sanjoy Mandal, Thomas Markiewicz, John Marshall, Aurelien Martens, Victoria Martin, Martina Martinello, Celso Martinez Rivero, Nobuhito Maru, John Matheson, Shigeki Matsumoto, Hiroyuki Matsunaga, Yutaka Matsuo, Kentarou Mawatari, Johnpaul Mbagwu, Peter McIntosh, Peter McKeown, Patrick Meade, Krzysztof Mekala, Petra Merkel, Satoshi Mihara, Víctor Miralles, Marcos Miralles Lopez, Go Mishima, Satoshi Mishima, Bernhard Mistlberger, Alexander Mitov, Kenkichi Miyabayashi, Akiya Miyamoto, Gagan Mohanty, Laura Monaco, Myriam Mondragon, Hugh E. Montgomery, Gudrid Moortgat-Pick, Nicolas Morange, María Moreno Llacer, Stefano Moretti, Toshinori Mori, Toshiyuki Morii, Takeo Moroi, David Morrissey, Benjamin Nachman, Kunihiro Nagano, Jurina Nakajima, Eiji Nakamura, Shinya Narita, Pran Nath, Timothy Nelson, David Newbold, Atsuya Niki, Yasuhiro Nishimura, Eisaku Nishiyama, Yasunori Nomura, Kacper Nowak, Mitsuaki Nozaki, María Teresa Nunez Pardo de Vera, Ines Ochoa, Masahito Ogata, Satoru Ohashi, Hikaru Ohta, Shigemi Ohta, Norihito Ohuchi, Hideyuki Oide, Nobuchika Okada, Yasuhiro Okada, Shohei Okawa, Yuichi Okayasu, Yuichi Okugawa, Toshiyuki Okugi, Takemichi Okui, Yoshitaka Okuyama, Mathieu Omet, Tsunehiko Omori, Hiroaki Ono, Tomoki Onoe, Wataru Ootani, Hidetoshi Otono, Shuhei Ozawa, Simone Pagan Griso, Alessandro Papa, Rocco Paparella, Eun-Kyung Park, Gilad Perez, Abdel Perez-Lorenzana, Yvonne Peters, Frank Petriello, Jonatan Piedra, Werner Porod, Christopher Potter, Alan Price, Yasser Radkhorrami, Laura Reina, Juergen Reuter, Francois Richard, Sabine Riemann, Robert Rimmer, Thomas Rizzo, Tania Robens, Roger Ruber, Alberto Ruiz Jimeno, Takayuki Saeki, Ipsita Saha, Tomoyuki Saito, Makoto Sakaguchi, Tadakatsu Sakai, Yasuhito Sakaki, Kodai Sakurai, Riccardo Salvatico, Fabrizio Salvatore, Yik Chuen San, Pearl Sandick, Tomoyuki Sanuki, Kollassery Swathi Sasikumar, Oliver Schaefer, Ruth Schaefer, Uwe Schneekloth, Thomas Schoerner-Sadenius, Carl Schroeder, Philip Schuster, Ariel Schwartzman, Reinhard Schwienhorst, Felix Sefkow, Yoshihiro Seiya, Motoo Sekiguchi, Kazuyuki Sekizawa, Katsumi Senyo, Hale Sert, Danielev Sertore, Ronald Settles, Qaisar Shafi, Tetsuo Shahdara, Barmak Shams Es Haghi, Ashish Sharma, Jessie Shelton, Claire Shepherd-Themistocleous, Hiroto Shibuya, Tetsuo Shidara, Takashi Shimomura, Tetsuo Shindou, Yutaro Shoji, Jing Shu, Ian Sievers, Frank Simon, Rajeev Singh, Yotam Soreq, Marcel Stanitzki, Steinar Stapnes, Amanda Steinhebel, John Stupak, Shufang Su, Fumihiko Suekane, Akio Sugamoto, Yuji Sugawara, Satoru Sugimoto, Yasuhiro Sugimoto, Hiroaki Sugiyama, Yukinari Sumino, Raman Sundrum, Atsuto Suzuki, Shin Suzuki, Maximilian Swiatlowski, Tim M. P. Tait, Shota Takahashi, Tohru Takahashi, Tohru Takeshita, Michihisa Takeuchi, Yosuke Takubo, Tomohiko Tanabe, Philip Tanedo, Morimitsu Tanimoto, Shuichiro Tao, Xerxes Tata, Toshiaki Tauchi, Geoffrey Taylor, Takahiro Terada, Nobuhiro Terunuma, Jesse Thaler, Alessandro Thea, Finn Tillinger, Jan Timmermans, Kohsaku Tobioka, Kouichi Toda, Atsushi Tokiyasu, Takashi Toma, Julie Torndal, Mehmet Tosun, Yu-Dai Tsai, Shih-Yen Tseng, Koji Tsumura, Douglas Tuckler, Yoshiki Uchida, Yusuke Uchiyama, Daiki Ueda, Fumihiko Ukegawa, Kensei Umemori, Junji Urakawa, Claude Vallee, Roberto Vega, Liliana Velasco, Silvia Verdu-Andres, Caterina Vernieri, Anna Vila, Ivan Vila Alvarez, Joost Vossebeld, Raghava Vsrms, Natasa Vukasinovic, Doreen Wackeroth, Moe Wakida, Liantao Wang, Masakazu Washio, Takashi Watanabe, Nigel Watson, Gordon Watts, Georg Weiglein, James D. Wells, Marc Wenskat, Susanne Westhoff, Glen White, Ciaran Williams, Stephane Willocq, Matthew Wing, Alasdair Winter, Marc Winter, Yongcheng Wu, Keping Xie, Tao Xu, Vyacheslav Yakovlev, Shuei Yamada, Akira Yamamoto, Hitoshi Yamamoto, Kei Yamamoto, Yasuchika Yamamoto, Masato Yamanaka, Satoru Yamashita, Masahiro Yamatani, Naoki Yamatsu, Shigehiro Yasui, Takuya Yoda, Ryo Yonamine, Keisuke Yoshihara, Masakazu Yoshioka, Tamaki Yoshioka, Fukuko Yuasa, Keita Yumino, Dirk Zerwas, Ya-Juan Zheng, Jia Zhou, Hua Xing Zhu, Mikhail Zobov, Fabian Zomer
Mikael Berggren, Maria Teresa Núñez Pardo de Vera, Jenny List
The direct pair-production of the superpartner of the $τ$-lepton, the $\widetildeτ$, is one of the most interesting channels to search for SUSY in: the $\widetildeτ$ is likely to be the lightest of the scalar leptons, and is one of the most experimentally chalanging ones. The current model-independent $\widetildeτ$ limits come from LEP, while limits obtained at the LHC do extend to higher masses, but are model-dependent. The future Higgs factories will be powerful facilities for SUSY searches, offering advantages with respect to previous electron-positron colliders as well as to hadron machines. In order to quantify the capabilities of these future $e^+e^-$ colliders, the "worst-case" scenario for $\widetildeτ$ exclusion/discovery has been studied, taking into account the effect of the $\widetildeτ$ mixing on $\widetildeτ$ production cross-section and detection efficiency. To evaluate the latter, the ILD concept, originally developed for the International Linear Collider (ILC), and the ILC beam conditions at a centre-of-mass energy of 500 GeV have been used for detailed simulations. The obtained exclusion and discovery reaches extend to only a few GeV below the kinematic limit even in the worst-case scenario. The results of the detailed simulation study are then discussed in view of the experimental environment of other proposed Higgs factory projects.
Maria Teresa Núñez Pardo de Vera, Mikael Berggren, Jenny List
The direct pair-production of the $\tildeτ$, is one of the most interesting channels to search for SUSY in: the $\tildeτ$ is likely to be the lightest of the scalar leptons, and the signature of $\tildeτ$ pair production is one of the experimentally most difficult ones, making it the ``worst'' possible scenario for SUSY searches. The current limit on $\tildeτ$ production in the general MSSM comes from LEP. Limits obtained at LHC do extend to higher masses, but they are only valid under strong assumptions. Future $e^+e^-$ colliders will be powerful for SUSY searches, offering advantages with respect to previous $e^+e^-$ colliders as well as to hadron machines. In order to quantify their capabilities, the ``worst-case'' scenario for $\tildeτ$ searches has been studied, taking into account the effect of the $\tildeτ$ mixing on both $\tildeτ$ production cross section and on detection efficiency. To evaluate the latter, the ILD detector concept, originally developed for the International Linear Collider (ILC), and the ILC beam conditions at a centre-of-mass energy of $500$\,GeV have been used for detailed simulations, including for the first time the effect of bunch-crossings containing no hard $e^+e^-$ interaction, but only low-$\it{P_{T}}$ hadrons from $γγ$ interactions and $e^+e^-$ pairs from beamstrahlung. Still, the obtained exclusion and discovery reaches extend nearly up to the kinematic limit even in the worst-case scenario. This remains true also when the $\tildeτ$ and the lightest SUSY particle are quite close in mass. The results of the detailed study are extrapolated to centre-of-mass energies, integrated luminosities and beam polarisations of other proposed Higgs factory projects and discussed in view of their respective experimental environments, in particular addressing the case of FCCee.
Jorge de Blas, Patrick Koppenburg, Jenny List, Fabio Maltoni, Juan Alcaraz Maestre, Juliette Alimena, John Alison, Patrizia Azzi, Paolo Azzurri, Emanuele Bagnaschi, Timothy Barklow, Matthew J. Basso, Josh Bendavid, Martin Beneke, Eli Ben-Haim, Mikael Berggren, Marzia Bordone, Ivanka Bozovic, Valentina Cairo, Nuno Filipe Castro, Marina Cobal, Paula Collins, Mogens Dam, Valerio Dao, Matteo Defranchis, Ansgar Denner, Stefan Dittmaier, Gauthier Durieux, Ulrich Einhaus, Mary-Cruz Fouz, Roberto Franceschini, Ayres Freitas, Frank Gaede, Gerardo Ganis, Pablo Goldenzweig, Ricardo Gonçalo, Rebeca Gonzalez Suarez, Loukas Gouskos, Alexander Grohsjean, Jan Hajer, Chris Hays, Sven Heinemeyer, André Hoang, Adrián Irles, Abideh Jafari, Karl Jakobs, Daniel Jeans, Jernej F. Kamenik, Matthew Kenzie, Wolfgang Kilian, Markus Klute, Sandra Kortner, Karsten Köneke, Marcin Kucharczyk, Christos Leonidopoulos, Cheng Li, Zoltan Ligeti, Elisa Manoni, Giovanni Marchiori, David Marzocca, Andreas B. Meyer, Ken Mimasu, Tristan Miralles, Victor Miralles, Abdollah Mohammadi, Stéphane Monteil, Gudrid Moortgat-Pick, Zohreh Najafabadi, María Teresa Núñez Pardo de Vera, Fabrizio Palla, Michael E. Peskin, Fulvio Piccinini, Laura Pintucci, Wiesław Płaczek, Simon Plätzer, Roman Pöschl, Tania Robens, Aidan Robson, Philipp Roloff, Nikolaos Rompotis, Andrej Saibel, André Sailer, Roberto Salerno, Matthias Schott, Reinhard Schwienhorst, Felix Sefkow, Michele Selvaggi, Frank Siegert, Frank Simon, Andrzej Siodmok, Torbjörn Sjöstrand, Kirill Skovpen, Maciej Skrzypek, Yotam Soreq, Raimund Ströhmer, Taikan Suehara, Junping Tian, Emma Torro Pastor, Maria Ubiali, Luiz Vale Silva, Caterina Vernieri, Alessandro Vicini, Marcel Vos, Aidan R. Wiederhold, Sarah Louise Williams, Graham Wilson, Aleksander Filip Zarnecki, Dirk Zerwas
In order to stimulate new engagement and trigger some concrete studies in areas where further work would be beneficial towards fully understanding the physics potential of an $e^+e^-$ Higgs / Top / Electroweak factory, we propose to define a set of focus topics. The general reasoning and the proposed topics are described in this document.
Tulika Bose, Antonio Boveia, Caterina Doglioni, Simone Pagan Griso, James Hirschauer, Elliot Lipeles, Zhen Liu, Nausheen R. Shah, Lian-Tao Wang, Kaustubh Agashe, Juliette Alimena, Sebastian Baum, Mohamed Berkat, Kevin Black, Gwen Gardner, Tony Gherghetta, Josh Greaves, Maxx Haehn, Phil C. Harris, Robert Harris, Julie Hogan, Suneth Jayawardana, Abraham Kahn, Jan Kalinowski, Simon Knapen, Ian M. Lewis, Meenakshi Narain, Katherine Pachal, Matthew Reece, Laura Reina, Tania Robens, Alessandro Tricoli, Carlos E. M. Wagner, Riley Xu, Felix Yu, Filip Zarnecki, Amin Aboubrahim, Andreas Albert, Michael Albrow, Wolfgang Altmannshofer, Gerard Andonian, Artur Apresyan, Kétévi Adikle Assamagan, Patrizia Azzi, Howard Baer, Michael J. Baker, Avik Banerjee, Vernon Barger, Brian Batell, Martin Bauer, Hugues Beauchesne, Samuel Bein, Alexander Belyaev, Ankit Beniwal, Mikael Berggren, Prudhvi N. Bhattiprolu, Nikita Blinov, Alain Blondel, Oleg Brandt, Giacomo Cacciapaglia, Rodolfo Capdevilla, Marcela Carena, Cesare Cazzaniga, Francesco Giovanni Celiberto, Cari Cesarotti, Sergei V. Chekanov, Hsin-Chia Cheng, Thomas Y. Chen, Yuze Chen, R. Sekhar Chivukula, Matthew Citron, James Cline, Tim Cohen, Jack H. Collins, Eric Corrigan, Nathaniel Craig, Daniel Craik, Andreas Crivellin, David Curtin, Smita Darmora, Arindam Das, Sridhara Dasu, Annapaola de Cosa, Aldo Deandrea, Antonio Delgado, Zeynep Demiragli, David d'Enterria, Frank F. Deppisch, Radovan Dermisek, Nishita Desai, Abhay Deshpande, Jordy de Vries, Jennet Dickinson, Keith R. Dienes, Karri Folan Di Petrillo, Matthew J. Dolan, Peter Dong, Patrick Draper, Marco Drewes, Etienne Dreyer, Peizhi Du, Florian Eble, Majid Ekhterachian, Motoi Endo, Rouven Essig, Jesse N. Farr, Farida Fassi, Jonathan L. Feng, Gabriele Ferretti, Daniele Filipetto, Thomas Flacke, Karri Folan Di Petrillo, Roberto Franceschini, Diogo Buarque Franzosi, Keisuke Fujii, Benjamin Fuks, Sri Aditya Gadam, Boyu Gao, Aran Garcia-Bellido, Isabel Garcia Garcia, Maria Vittoria Garzelli, Stephen Gedney, Marie-Hélène Genest, Tathagata Ghosh, Mark Golkowski, Giovanni Grilli di Cortona, Emine Gurpinar Guler, Yalcin Guler, C. Guo, Nate Graf, Ulrich Haisch, Jan Hajer, Koichi Hamaguchi, Tao Han, Philip Harris, Sven Heinemeyer, Christopher S. Hill, Joshua Hiltbrand, Tova Ray Holmes, Samuel Homiller, Sungwoo Hong, Walter Hopkins, Shih-Chieh Hsu, Phil Ilten, Wasikul Islam, Sho Iwamoto, Daniel Jeans, Laura Jeanty, Haoyi Jia, Sergo Jindariani, Daniel Johnson, Felix Kahlhoefer, Yonatan Kahn, Paul Karchin, Thomas Katsouleas, Shin-ichi Kawada, Junichiro Kawamura, Chris Kelso, Elham E Khoda, Valery Khoze, Doojin Kim, Teppei Kitahara, Juraj Klaric, Michael Klasen, Kyoungchul Kong, Wojciech Kotlarski, Ashutosh V. Kotwal, Jonathan Kozaczuk, Richard Kriske, Suchita Kulkarni, Jason Kumar, Manuel Kunkel, Greg Landsberg, Kenneth Lane, Clemens Lange, Lawrence Lee, Jiajun Liao, Benjamin Lillard, Lingfeng Li, Shuailong Li, Shu Li, Jenny List, Tong Li, Hongkai Liu, Jia Liu, Jonathan D Long, Enrico Lunghi, Kun-Feng Lyu, Danny Marfatia, Dakotah Martinez, Stephen P. Martin, Navin McGinnis, Karrick McGinty, Krzysztof Mękała, Federico Meloni, Oleksii Mikulenko, Ming Huang, Rashmish K. Mishra, Manimala Mitra, Vasiliki A. Mitsou, Chang-Seong Moon, Alexander Moreno, Takeo Moroi, Gerard Mourou, Malte Mrowietz, Patric Muggli, Jurina Nakajima, Pran Nath, J. Nelson, Matthias Neubert, Laura Nosler, Maria Teresa Núñez Pardo de Vera, Nobuchika Okada, Satomi Okada, Vitalii A. Okorokov, Yasar Onel, Tong Ou, Maksym Ovchynnikov, Rojalin Padhan, Priscilla Pani, Luca Panizzi, Andreas Papaefstathiou, Kevin Pedro, Cristián Peña, Federica Piazza, James Pinfold, Deborah Pinna, Werner Porod, Chris Potter, Markus Tobias Prim, Stefano Profumo, James Proudfoot, Mudit Rai, Filip Rajec, Reese Ramos, Michael J. Ramsey-Musolf, Javier Resta-Lopez, Jürgen Reuter, Andreas Ringwald, Chiara Rizzi, Thomas G. Rizzo, Giancarlo Rossi, Richard Ruiz, L. Rygaard, Aakash A. Sahai, Shadman Salam, Pearl Sandick, Deepak Sathyan, Christiane Scherb, Pedro Schwaller, Leonard Schwarze, Pat Scott, Sezen Sekmen, Dibyashree Sengupta, S. Sen, Anna Sfyrla, Eric Shackelford, T. Sharma, Varun Sharma, Jessie Shelton, William Shepherd, Seodong Shin, Elizabeth H. Simmons, Zoie Sloneker, Carlos Vázquez Sierra, Torbjörn Sjöstrand, Scott Snyder, Huayang Song, Giordon Stark, Patrick Stengel, Joachim Stohr, Daniel Stolarski, Matt Strassler, Nadja Strobbe, Julia Gonski, Rebeca Gonzalez Suarez, Taikan Suehara, Shufang Su, Wei Su, Raza M. Syed, Tim M. P. Tait, Toshiki Tajima, Andy Tang, Xerxes Tata, Teodor Tchalokov, Andrea Thamm, Brooks Thomas, Natalia Toro, Nhan V. Tran, Loan Truong, Yu-Dai Tsai, Eva Tuecke, Nikhilesh Venkatasubramanian, Chris B. Verhaaren, Carl Vuosalo, Xiao-Ping Wang, Xing Wang, Yikun Wang, Zhen Wang, Christian Weber, Glen White, Martin White, Anthony G. Williams, Brady Williams, Mike Williams, Stephane Willocq, Alex Woodcock, Yongcheng Wu, Ke-Pan Xie, Keping Xie, Si Xie, C. -H. Yeh, Ryo Yonamine, David Yu, S. -S. Yu, Mohamed Zaazoua, Aleksander Filip Żarnecki, Kamil Zembaczynski, Danyi Zhang, Jinlong Zhang, Frank Zimmermann, Jose Zurita
M. T. Núñez Pardo de Vera, M. Berggren, J. List
Pair-production of the superpartner of the $τ$-lepton, the $\tildeτ$, is one of the most interesting channels to search for SUSY in: The $\tildeτ$ is likely to be the lightest scalar lepton, and the signature of $\tildeτ$ pair production is one of the experimentally most difficult ones, thereby constituting the "worst" possible scenario for SUSY searches. The current model-independent $\tildeτ$ limits comes from analyses performed at LEP but they suffer from the limited energy of this facility. Limits obtained at the LHC do extend to higher masses, but they are only valid under strong assumptions. The International Linear Collider, the ILC, is a future electron-positron collider, to operate initially at an energy of 250 GeV, then to be upgraded to 500 GeV, and possibly to 1 TeV at a later stage. ILC will be a powerful facility for SUSY searches. The capability of the ILC for determining exclusion/discovery limits for the $\tildeτ$ in a model-independent way is shown in this paper. A detailed study of the "worst" scenario for $\tildeτ$ exclusion/discovery, taking into account the effect of the $\tildeτ$ mixing on $\tildeτ$ production cross-section and detection efficiency, is presented. The study also includes an analysis of the effect of the overlay particles in the $\tildeτ$ searches. The conclusion is that both the exclusion and discovery reaches for this "worst" case would extend to only a few GeV below the kinematic limit at the ILC. Also scenarios with the $\tildeτ$ and the Lightest SUSY Particle (the LSP) quite close in mass can be discovered or excluded at most $\tildeτ$ masses. The studies were done using detailed detector simulation of the ILD concept at the ILC. For signal, the fast detector simulation SGV was used, while the full Geant4 based DDSim was used for the standard model backgrounds.
M. T. Núñez Pardo de Vera, M. Berggren, J. List
The direct pair-production of the superpartner of the $τ$-lepton, the $\widetildeτ$, is one of the most interesting channels to search for SUSY in. First of all, the $\widetildeτ$ is likely to be the lightest of the scalar leptons. Secondly the signature of $\widetildeτ$ pair production signal events is one of the experimentally most difficult ones, thereby constituting the "worst" possible scenario for SUSY searches. The current model-independent $\widetildeτ$ limits comes from analyses performed at LEP but they suffer from the limited energy of this facility. Limits obtained at the LHC do extend to higher masses, but they are only valid under strong assumptions. ILC, a future electron-positron collider with energy up to 500 GeV and upgrade capability\footnote{The initial ILC energy is planned to be 250 GeV.}, is a promising facility for SUSY searches. The capability of the ILC for determining exclusion/discovery limits for the $\widetildeτ$ in a model-independent way is shown in this paper, together with an overview of the current state-of-the-art. Results of the last studies of $\widetildeτ$ pair-production at the ILC are presented, showing the improvements with respect to previous results.
M. T. Núñez Pardo de Vera, M. Berggren, J. List
One of the most interesting channels to search for SUSY is the direct pair-production of the $τ$-lepton superpartner, $\widetildeτ$. The $\widetildeτ$ is with high probability the lightest of the scalar leptons, so one of the first SUSY particles that can be observerd, and the signature of $\widetildeτ$ pair production signal events is one of the most difficult ones, yielding to the ``worst'' and so most global scenario for the searches. Analysis performed at LEP set the current model-independent $\widetildeτ$ limits, suffering from the low energy of this facility. Only under strong model assumptions, these limits are extended to higher masses by LHC studies. In this contribution we show the capability of the ILC, a future electron-positron collider with energy up to 1 TeV, for determining $\widetildeτ$ exclusion/discovery limits in a model-independent way, including an overview of the current state-of-the-art. The determination of the ``worst'' scenario for $\widetildeτ$ exclusion/discovery, taking into account the effect of the $\widetildeτ$ mixing on $\widetildeτ$ production cross-section and efficiency, is also presented. For selected benchmarks, the prospect for measuring masses and polarised cross-sections will be shown. The studies were done studying events passed through the full detector simulation and reconstruction procedures of the International Large Detector (ILD) concept at the ILC. The simulation included all SM backgrounds, as well as the machine induced ones.