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Beyond the Standard Model: Composite Higgs and Dark Matter

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Beyond the Standard Model: Composite Higgs and Dark Matter BEYOND THE STANDARD MODEL: COMPOSITE HIGGS AND DARK MATTER A Dissertation Presented to the Faculty of the Graduate School of Cornell University in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy by Ofri Telem August 2019 c 2019 Ofri Telem ALL RIGHTS RESERVED BEYOND THE STANDARD MODEL: COMPOSITE HIGGS AND DARK MATTER Ofri Telem, Ph.D. Cornell University 2019 The Standard Model (SM) of particles and interactions provides some of the most extensively tested predictions in science. However, it does not adequately describe quantum gravity, and does not contain a suitable candidate for Dark Matter. Furthermore, the UV sensitivity of the SM Higgs sector suggests that new states beyond the SM might exist at energies not far above the weak scale. This dissertation explores potential scenarios for physics beyond the SM, either in a dark sector or linked to the Higgs sector of the SM. The first part of this work includes two novel classes of composite Higgs models, with far reaching phenomenological consequences. In the first of these, an adjustable tree-level Higgs quartic coupling, allows for a significant reduc- tion in the tuning of the Higgs potential. The quartic in this model originates from the dimensional reduction of a 6D theory, and is the first example of a holo- graphic composite Higgs model with a tree-level quartic. In the second novel class of composite Higgs models, the top and gauge partners responsible for cut- ting off the Higgs quadratic divergences form a continuum. A concrete example is presented, based on a warped extra dimension with a linear dilaton, where this finite gap appears naturally. Spectral densities are derived for this model, as well as the full Higgs potential for a phenomenologically viable benchmark point, with percent level tuning. The continuum top and gauge partners in this model evade all resonance searches at the LHC and yield qualitatively different collider signals. The second part of this work features two different classes of models for an extended dark sector that undergoes either confinement or bound states forma- tion. It is shown how each of these mechanisms could lead to vast modifications of early universe dynamics, as well as unique signals today. In the first of these, the relic abundance of heavy stable particles charged under a confining gauge group is depleted by a second stage of annihilations near the deconfinement temperature. This mechanism can be used to construct ultra-heavy dark-matter models with masses above the naive unitarity bound. The second contribution is Self-Destructing Dark Matter (SDDM), a new class of dark matter models which are detectable in large neutrino detectors. In this class of models, a com- ponent of dark matter can transition from a long-lived state to a short-lived one by scattering off of a nucleus or an electron in the Earth. The short-lived state then decays to SM particles, generating a dark matter signal with a visible en- ergy of order the dark matter mass rather than just its recoil. BIOGRAPHICAL SKETCH Ofri Telem was born in Israel on July 20th, 1989, and grew up in the town of Modi’in. At age 15, he attended the Israel Art and Science Academy in Jerusalem, where he majored in Physics, Mathematics, Computer Science and Philosophy. At age 18, he enlisted in the Israel Defense Forces (IDF), serving in Talpiot, the IDF’s elite technological training program. As part of the training, he completed a bachelor’s degree in Physics and Mathematics at the Hebrew University, Jerusalem. Towards the end of his military training in 2010, Ofri met Laura, the love of his life, on a “Birthright Israel” trip, and the two lived together in Israel until moving to the US in 2016. Ofri and Laura were married in 2015, and are expect- ing their first child. In the years 2010-2016, Ofri served as an R&D officer in the IDF, and was granted the rank of Major. During his service, Ofri completed a Master’s degree in Physics at the Technion - Israel Institute of Technology, under the supervi- sion and mentorship of Professor Yael Shadmi. Ofri is particularly indebted to Professor Shadmi for introducing him to the world of High Energy Physics. To- gether with his close friend and collaborator Dr. Michael Geller, Ofri published the first Composite Higgs UV completion of the Twin Higgs model, which was the first in a wave of renewed interest in the Twin Higgs model. In the fall of 2016, Ofri started his graduate studies at Cornell University, un- der the supervision and mentorship of Professor Csaba Csaki.´ Professor Csaki´ provided Ofri with endless support, ideas, care and guidance, and Ofri con- siders him a lifelong mentor. In the fall, after the birth of his first child, Ofri will continue his work in theoretical High Energy Physics as a postdoctoral re- searcher at the University of California, Berkeley. iii To my loved ones, and the one to come. iv ACKNOWLEDGEMENTS Before jumping into the physics, I would like to thank my parents, Tali and Itiel, and my sister Liri. Moving to a different country to pursue your dream is an extremely hard thing, especially for a tight-knit family like ours. Ima, Aba and Liri, I love you and miss you every day. Laura, my love and my soulmate. Having you by my side makes everything better. Thank you for listening to me talk about dark matter before we’ve even had coffee. And now to physics. Throughout my short career so far in High Energy Physics, I’ve had the immense luck and pleasure to have three extraordinary particle physicists guide my path. The first is Michael Geller, my first (and hopefully lifelong) collaborator. From Michael I learned that ideas need to be sharp and crystal clear, and that good physicists are ones who are brutally honest with themselves. Another thing that I learned from Michael is that you need to know what to expect from a calculation ahead of time - otherwise the result is just some random output from a black box. I thank Michael for being my scientific older brother, with whom I can share any idea that I have, and get laser focused feedback. The second particle physicist who guides my path is Yael Shadmi. I did my Master’s degree under her supervision at the Technion in the years 2012-2015, and enjoyed her wisdom. I learned from Yael how to write physics papers, and especially how to galvanize a physics idea and attack it from every possible angle, until it reaches maturity. Several times I rushed ahead in my eagerness to push a project forward, only to come full circle to Yael’s original understanding of the physics. I thank Yael for helping me become a more mature physicist. Last, but not least, I would like to thank Csaba Csaki,´ my mentor. In Csaba I v found a deep thinker, who is on the path to a better understanding of Quantum Field Theory. It’s hard to summarize everything that I learned from Csaba, but if I have to name one thing, it would be to dare to ask the big questions. It’s very tempting to get carried away by scientific fads, or to get lost in some techno- cratic number crunching. Csaba reminds me time and again that there are still so many wonderful things to understand better - be it instantons, monopoles, dualities or any other mind blowing concept, and that even people like me, who are no Ken Wilson, can maybe one day discover something truly deep. I am in- debted to Csaba for bringing me to Cornell and giving me all the support in the world. I couldn’t have asked for a better advisor. I have many other thanks to give, so from now on I will have to make it shorter... I thank Julia Thom-Levy and Maxim Perelstein for being on my committee, and also thank Maxim for many interesting physics discussions. Yuval, toda for all the fun ideas that we had together and for being there when I need a little bit of home away from home. Thank you to my dear collaborators Csaba Csaki,´ Yael Shadmi, Michael Geller, Sal Lombardo, Gabe Lee, Sho Iwamoto, Seung Lee, Roni Harnik, Yue Zhang, and Andi Weiler. I am also grateful to a host of other particle physicist with whom I’ve had the pleasure to talk physics. The list is far from exhaustive, and I am sorry if I forgot anyone: Nima Arkani-Hamed, John Terning, Yuri Shirman, Jay Hubisz, Liam McAllister, Tom Hartman, Eric Kuflic, Yonit Hochberg, Tomer Volansky, Gilad Perez, Yevgeny Kats, Nathaniel Craig, David Curtin, Jonathan Feng, Jeff Dror, Jack Collins, Hari Ramani, Oren Slone, Gustavo Marques-Tavares, Yushin Tsai, Kim Berghaus, Shaouly Bar-Shalom, Gad Eilam, Yaniv Weiss, Eitan Gozani, Yoav Afik, and many more. I would like to express my gratitude to the UMD physics department for vi their hospitality and their support. I was honored and grateful for the opportu- nity to talk to Raman Sundrum, Zackaria Chacko, Kaustubh Agashe, and Anson Hook. To the physics department at UC Berkeley - I am eager and excited to start working together. I thank Hitoshi Murayama, Lawrence Hall, Zoltan Ligeti, Yasunori Nomura and Christian Bauer for the opportunity. See you soon! Thank you to the power trio - Jeff Dror, Sal Lombardo, and Jack Collins. You guys are the best. Thank you to all the friends that I’ve had at Cornell - on the the post-doc side, Sungwoo Hong, Matt Klimek, Edgar Shagoulian, and Kartik Prabhu.
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