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 2012 Winter camp.
Mondays, 1:30pm -- 3:00pm
Physical Sciences Building, Room 470
Contact:
This is now an archived page that is no longer updated.
Return to the current journal club page.
Spring 2012 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 2010 Abstracts
- Light Dark Matter, Yuhsin Tsai (30 Jan).
Light Dark Matter (LDM) models which have DM masses in the keV to GeV range are both experimentally and theoretically motivated. The corresponding parameter space of these models has not been reached by the current direct detection experiments. It then is interesting to look for other experimental constraints. In this talk, we introduce some examples -- WIMPless, MeV and Sterile neutrino DM -- to have a taste in the LDM model building, and talk about the possible direct detection bounds of sub-GeV DM. We also mention the current cosmological and collider constraints on DM in the range of MeV to GeV scale. Reference: notes
- Dynamical SUSY Breaking, Mario Martone (6 Feb).
The idea of dynamical supersymmetry breaking involves a lot of cool stuff: asymptotic gauge theories, your favorite non-perturbative effect, strongly coupled regimes, etc.. In my get-ready-for-the-A-exam monday talk I'll try to review all that. Specifically I'll introduce the general features of SUSY breaking. Discussing in some details the non-renormalization theorem to then motivate the idea of dynamical supersymmetry breaking. I will then use the full power of SUSY (called also "holomorphy") to discuss non-perturbative effects in SYM theories with chiral matter. Developing this machinery will allow us to finally discuss one explicit example where SUSY is in fact dynamically broken.
. Reference: n/a.
- Running Off a Cliff: Implication of the Higgs mass measurement on the stability of the Standard Model, Nicolas Rey-Le Lorier (13 Feb).
This presentation will examine some of the theoretical fallout of the recent (probable!) measurement of the Higgs mass around the 125 GeV mark. We will see that this measurement, coupled with the radiatively induced running of the SM parameters, implies a possible instability for the electroweak vacuum at a scale of about 10^11 GeV, thought stability up to the Planck scale is still allowed by theoretical and experimental errors.
Reference: 1112.3022, review.
- Jet substructure and boosted object tagging, Josh Berger (20 Feb).
I will demonstrate how to use FastJet to implement standard modern jet reconstruction algorithms and to tag boosted top decays. I will begin with a brief overview of modern jet reconstruction and its relation to substructure. I will then examine the Johns Hopkins and N-subjettiness-based algorithms for boosted object tagging. The bulk of my talk will be focused on practical implementations of these algorithms for use with MadGraph event files. Participants are encouraged to bring their computers and to follow along using the package posted online. Reference: FastJet manual, 0806.0848, 1011.2268. Anyone who plans to follow along should have Pythia and FastJet installed as per the Winter Camp instructions. Everything else that is required is included there. Software: download.
- Out of this world SUSY breaking, Bibhushan Shakya (27 Feb).
This week we (re)visit a classic: "Out of This World Supersymmetry Breaking" by Randall and Sundrum, one of the pioneering papers on anomaly-mediated supersymmetry breaking. Reference: hep-th/9810155.
- 5D Locality in 4 Dimensions, Flip Tanedo (5 March).
5D models are effective theories that can be UV completed through dimensional deconstruction: 4D theories where the extra dimension is interpreted as a string of linked gauge groups (a moose or quiver diagram). We will investigate the relation between 5D ("theory space") locality and weak coupling of the deconstructed nonlinear sigma model. Maybe there’ll be a short discussion on why this is interesting from the point of view of recent 5D penguin (Totoro) calculations. Reference: 1202.5491.
- Flavor Oscillation from the Two-Point Function, Dean Robinson (12 March).
The well-known neutrino and neutral-meson oscillation probability formulae can both be derived from a formalism that relies only on the structure of two-point Green's functions. The generality of this approach permits the investigation of flavor oscillation in exotic parameter regimes. We'll discuss the details of this description and its results, as well as how it compares to other approaches to flavor oscillation. Reference: 1103.3486.
- Gong Show, Spring Break (19 March).
Gong Show. No talk this week. For people who are around, we can do a research gong show. Each person gives a 3-5 minute talk on their current research with a strict upper limit. Person with the best talk gets bragging rights. Reference: Reference.
- Brane theories with 5D gravity at long distances, Mathieu Cliche (26 Mar).
In most brane models the 5D manifestation of gravity occurs only at short distances and gravity at long distances is effectively 4D. In this talk I will present two brane models in which this is not the case, that is gravity is effectively 5D for short and long distances but remain 4D at intermediate distances. The first model, GRS, uses three branes in such a way that the fifth dimension is warped near the brane we live in and flat far away from it. The second model, DGP, uses a completely flat fifth dimension but with an induced Ricci scalar on the brane we live in. Finally, I will show using holographic RG that the two models are equivalent at long distances. Reference: 1103.3708, arXiv:hep-th/0005016, arXiv:hep-th/0003076.
- Split Families Unified, Jack Collins (2 Apr).
I will be talking about a paper which Flip suggested to me a few weeks ago, 'Split families unified' by N. Craig, S. Dimopoulos, T. Ghergetta, arXiv:1203.0572 [hep-ph] (March 2012). Also, this is largely based on things which were laid out in a 2011 paper by N. Craig, D. Green, A. Katz arXiv:1103.3708 [hep-ph]. The general idea is to build a simplified model which solves many of the flavour and naturalness problems of the MSSM using a two-site deconstruction where the light and heavy fermion generations are placed in two separate copies of the SM gauge groups which are higgsed down to the diagonal. I am not sure how much of this paper I will have understood by Monday, but there is a good chance that it will be you guys teaching me more than I am telling you, but that is good too :). Reference: 1103.3708, 1203.0572
- Personal (Jet) Grooming, Mike Saelim (30 Jan).
Higher beam energies and intensities at the LHC increase the effects from initial state radiation, pile-up, and the underlying event, which disrupt proper jet clustering and destroy sensitive measurements of jet substructure, missing energy and other variables. Jet grooming techniques such as filtering, trimming, pruning, and filtripruning control these effects and are employed at LHC experiments. We will study these techniques as applied to jet clustering and boosted object tagging. Reference: 0802.2470,
0912.0033,
0912.1342, etc.
- Supergravity for Phenomenologists, David Marsh (16 April).
David will present aspects of supergravity (SUGRA) for the phenomenology journal club. He will present an alternative gauge fixing for conformal SUGRA which decouples gravitational complications that arise in the usual conformal compensator formalism. If time permits, he will also present aspects of anomaly mediation from this perspective.
. Reference: n/a.
- NGB Higgs PHysics, Javi Serra (23 April).
Special guest talk by Javier Serra-Mari, who has the following message [sic]: "I wanted to talk about NGB-Higgs. Would you like that? Because I will like to draw the attention of some of you towards the subject. So maybe you want to do something." Translation: “Hello, my name is Inigo Montoya, you killed my father, prepare to die. Topics may include: the Higgs as a [pseudo] Nambu-Goldstone boson, how to find the six-fingered man. Reference: 1005.4269.
- New Physics in Kaons, Monika Blanke (30 April).
In this talk I want to give you a flavor of today's hot topics in kaon physics. K decays are a particularly interesting place to look for BSM physics, thanks to their strong suppression within the SM and to their theoretical cleannes. I will then focus on two specific observables, namely CP-violation in neutral kaon mixing and the rare K -> pi nu anti-nu decays, for which I will discuss both the SM prediction and new contributions in various BSM scenarios. Reference: Intensity Frontier Slides.
- Pheno, No speaker (---).
No talk. Reference: No reference.
2012 Winter Workshop: January 2012
This will be a week-long, in-depth student workshop (Winter Camp) focusing on Collider Monte Carlo, from 17-22 January 2012. Meetings will be roughly 10 - 5pm every day with all participants in the same room. Each day will have a convener and a closing summary talk with ample time for discussion. The workshop website is here.
Resources
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.
Guidelines
- 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.
History
The current BSM journal club was started in 2007 by Flip Tanedo, David Curtin, Itay Nachshon, Josh Berger, and Yuhsin Tsai. Previous manifestations include a collider journal club organized by Matt Reece and Patrick Meade. In the distant past Michael Peskin explains that the students had a "Gradshteyn" seminar since it was meant to integrate the collective knowledge of the graduate students.