BSM Journal Club
The particle theory graduate student journal club meets once a week to discuss topics of interest in beyond the Standard Model phenomenology and model building. Topics roughly alternate between review articles and new papers.
See also the 2013 Winter camp on the duality cascade.
Mondays, 1:30pm -- 3:00pm
Physical Sciences Building, Room 470
Archives of past semesters:
BSM Club Fall 2009
BSM Club Spring 2010
BSM Club Fall 2010
BSM Club Spring 2011 (geometry)
BSM Club Fall 2011 (colliders)
BSM Club Spring 2012
BSM Club Fall 2012
Spring 2013 Schedule
Topics marked (R) are review talks where some previous reading is recommended but not necessary. Otherwise topics are "current papers" and everyone is expected to have read the main paper in advance.
Spring 2013 Abstracts
- Seiberg-Witten, Mario Martone (21 Jan).
In this talk we will introduce the main ideas beyond the magnificent work of Seiberg-Witten who were able to exactly solve N=2 SUSY SU(2) gauge theories. We will only discuss the pure gauge case leaving for further discussion the presence of matter. Given the complexity of the topic, we will mainly focus on the ideas, outlining the chain of reasoning and only occasionally delve into more detailed calculations. Most of the talk will focus on providing the background, which includes a brief discussion on monopoles, N=2 SUSY, central charge extension of SUSY algebra and non-perturbative methods. Towards the end we hope to at least give a taste of the exact results. Reference: hep-th/9701069.
- SUSY gauge theory in d=3, Flip Tanedo (28 Jan).
Dimensional reduction of N=1 SUSY in d=4 gives a N=2 theory in d=3. We comment on the features of this theory, focusing on the phase structure, dualities, monopoles, and connections to 4D physics. We will draw upon the intuition developed studying the duality cascade during this year’s winter camp.
Reference: hep-th/0309149, hep-th/9703110.
- Emergence of the EW Scale Through the Higgs Portal, Nic Rey-Le Lorier (4 Feb).
I will present a recent paper by Englert et al. which proposes to use the Coleman-Weinberg method to generate symmetry-breaking in a hidden sector and then transmit it to the standard model through a Higgs portal. This yields a completely natural setup with a phenomenology that can be tested at the LHC. However, this approach raises a few conceptually tricky issues regarding the nature of fine-tuning and renormalization, which we will examine.". Reference: 1301.4224.
- Shining and Sniffing, Mathieu (11 Feb).
No abstract. Reference: hep-ph/9909326.
- Everything you wanted to know about Chern and Simons, Mario (11 Feb).
After a pedagogical introduction of Chern-Simons terms in generic odd-dimension, we will discuss some of their properties including (hopefully) their role in dualities among SUSY gauge theory in 3d. In turn we will enlighten the role played by Chern-Simons terms in parity anomaly calculations which turns out to be a very useful tool to identify IR-dualities in 3d. Its use it is very much analog to the 't Hooft anomaly matching condition for 4d theories and their dualities. Reference: B. Willett's thesis,
- Jet Charge Distributions, Jack Collins (25 Feb).
I think I will give a talk on jet charge distributions, focusing on arXiv:1209.2421 and important refs. I will provide an abstract probably on Thursday. Hopefully I can understand the technical discussion of pages 3-5 on fragmentation functions etc. by Monday. Reference: 1209.2421.
- 1/N and emergent gauge fields, Riccardo Pavesi (4 March).
I'll discuss the 1/N expansion for solving QFTs exactly, we will go through the phi^4 example quickly in order to discuss the more interesting CP^N model, where a two dimensional non linear scalar field generates an effective gauge interaction. Reference: 1/N in Coleman,
Nucl.Phys. B149 285,
Peskin (p. 463-468).
- Naturalness of Supersymmetry, and its Many Caveats, Bibhushan Shakya (11 MArch).
A timely review of the concept of naturalness in supersymmetry, its status, and several related subtleties as discussed in this recent article, complemented by some related ideas from my current research projects and the latest LHC results from Moriond. . Reference: 1302.6587.
- No talk.
- Alphabets of perturbations in Twistor space, Sina Bahrami (25 March).
This is an introductory talk about the fundamentals of perturbative gauge theory examined in Twistor space. After providing a concise introduction about the fundamentals of Twistor theory, we will explain how Twistors can be used as a proper language for calculating scattering amplitudes. If time permits, we will also consider Twistors in curved space-time. Reference: Twistor Theory by Penrose and MacCallum, hep-th/0312171, 0903.2110.
- Dragging SUSY Through the UDD:
Saving Naturalness Through Parity Violation, Nicolas Rey-Le Lorier
The gluino is constrained to be heavier than 1 TeV by three years of LHC measurements, spelling trouble for naturalness. However, by allowing R-Parity violation through UDD operators, we can remove the missing energy signal and obtain a natural spectrum which has not been excluded yet. We will present a model based on SU(5) x U(3) product unification, which gives us the desired UDD couplings and natural spectrum, and discuss its phenomenology. Reference: 1301.2336.
- SUSY Breaking in Superspace, Flip Tanedo (8 April).
We review the use of analytic continuation into superspace using the soft terms in gauge mediation as an example for how this method can allows one to determine higher-loop level corrections using holomorphy. We then demonstrate how one may map UV soft terms across a duality by extending this spurion analysis. Reference: hep-th/9804068.
- Scattering Amplitudes, Part 2, Dean Robinson (15 April).
I'll be talking about the one-loop scattering amplitudes stuff I didn't get to last time. Reference: hep-ph/9601359.
- Gong Show.
Come prepared with a 5 minute chalkboard talk for the group: current research, ideas, recent papers. Talks will be tactlessly 'gonged' if they go over the strictly enforced time limit.
- Hidden gauge symmetry and Seiberg Duality, Mario Martone (29 April).
In what sense is Seiberg Duality a way to understand the infrared limit of a strongly coupled SUSY gauge theory? We show how one can understand the Seiberg magnetic theory in terms of a hidden local symmetry with respect to a nonlinear sigma model. In this interpretation the gauge field is identified with the rho meson. Reference: 1010.4105.
- talk15, talk15speaker (date).
talk15. Reference: Reference.
- talk16, talk16speaker (date).
talk16. Reference: Reference.
- talk17, talk17speaker (date).
talk17. Reference: Reference.
2013 Workshop: January 2013
This will be a week-long, in-depth student workshop (Winter Camp) focusing on the duality cascade, from 14-18 January 2013. Meetings will be roughly 10 - 5pm every day in PSB 470. Each day will have a convener and a closing summary talk with ample time for discussion. Reference: hep-th/0505153.
Unsure about places to start looking for talk ideas? Here are a few suggestions, geared towards the pedagogical side.
- Collections of reviews and lectures: The Net Advance of Physics, Ulrich Theis' page, or The String Wiki.
- It may also be worth looking through journals that specialize in review articles: RMP, Physics Reports, Annual Reviews, Reports on Progress in Physics, Proceedings of Science, Living Reviews.
- You can also use tools like SPIRES and arXiv Structure to find papers and reviews. For example, you can search for proceedings from summer schools (TASI, Les Houches, SLAC, Cargese, Cracow)
Scanning: it is often helpful to share your notes with the journal club, especially for review talks. Hand written notes may be scanned easily using the LASSP document scanner on the 5th floor of Clark or Mann library (photocopiers with free scanning option). These have automatic document feeders and can e-mail you a pdf of your notes.
- Announce your topic two weeks in advance, include a link to the relevant paper(s).
- You should give one pedagogical talk and one 'new paper' talk over the course of the semester.
- All members are required to have read 'new papers' that are being presented. Pedagogical talks should be accessible without pre-reading. Review and 'new paper' talks should alternate to give students time to read the new paper.
- Use discretion when presenting a new paper; if it is based on a topic that is unfamiliar to our group, it would be better to coordinate a pedagogical talk before presenting the paper.
- Speakers should focus on leading a discussion rather than giving a 1.5 hour lecture; students are expected to participate actively. Chalkboard talks are strongly preferred.
- Because of the composition of pheno students we have, we are in a unique position to take advantage of this kind of activity. This will only work if we all make this a priority.