BSM Journal Club

The particle theory graduate student journal club ("Pheno Club") meets once a week to discuss topics of interest in phenomenology. Topics roughly alternate between review articles and new papers.

Mondays, 1:30pm -- 3:15pm
Newman Lab, Room 311
Contact:

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Spring 2010 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

• Strongly Coupled Gauge Theory, Yong-hui Qi (1 Feb)
  I will discuss the physics of strongly coupled gauge theories, from ordinary space-time to super-space. Firstly we briefly review the topological objects of Yang-Mills theory in ordinary space-time. We will then extend our discussion to Super Yang-Mills with matter added. We focus on holomorphic gauge couplings and the ADS superpotential, NSVZ beta function as well as its relations to 4D CFT and Seiberg duality. Finally we discuss Seiberg-Witten theory. The application to gauge-mediated dynamical SUSY breaking based on MSSM is straightforward. We will mainly focus on SUSY with N less than or equal to 2.
• Supergraphs, Flip Tanedo (8 Feb)
  Supergraphs are a relic of the time when Pac-Man was considered an addicting video game. I will review the formalism derivation of Feynman rules on superspace and demonstrate the manifest cancellations of divergences using the supergraph method. If time permits, I will motivation the calculation of the effective Kahler potential using supergraph techniques.
• General Gauge Mediation, Yuhsin Tsai (15 Feb)
  General Gauge Mediation (GGM) parameterizes the soft terms from the entire space of possible models of gauge mediated supersymmetry breaking. I will describe the GGM framework and discuss its phenomenology. We will review 0801.3278 and 0812.3668.
• Remarks on the Warped Deformed Conifold, Stefan Sjors (22 Feb)
  I will discuss the review article "Remarks on the Warped Derformed Conifold" by Hertzog, Klebanov and Ouyang, hep-th/0108101. Following the calculations outlined in the review, I will show that the "warped deformed conifold" is indeed a solution to type IIB supergravity. Then using the gauge/gravity correspondence we can infer the beta functions of the dual theory, a supersymmetric SU(N+M)xSU(N) gauge theory.
• Supersymmetry at the Tevatron, Josh Berger (1 March)
  I will discuss a recent study of the phenomenology of models with General Gauge Mediation, focusing on regions of parameter space with neutralino NLSPs that decay promptly. In particular, I focus on signals that could be observed in current or near-future data at the Tevatron. I will systematically go over the signals for the possible scenarios within this setup. Many of these signals have been neglected to this point and bounds on the corresponding theories are weak. In addition, I would like to discuss aspects of the study relating to more general collider studies by theorists. This will not be a review, so I expect everyone to have read the reference and hopefully have attended the recent talk by Matt Reece. Reference: 0911.4130.
• Implications of CoGeNT and DAMA for Light WIMP Dark Matter, Bibhushan Shakya (8 March)
  This 'new paper' talk discusses the latest in direct dark matter detection: recent measurements by the CoGeNT collaboration, which point to a GeV scale dark matter with an elastic scattering cross section of order 10^-41 cm². We will discuss its consistency with other direct detection experiments (DAMA, CDMS, XENON), two dark matter candidates - Asymmetric Dark Matter and neutralinos in NMSSM - that naturally explain these observations, and implications for indirect detection. The talk is based on 1003.0014, CoGeNT results are presented in 1002.4703.
• Complete Mass Determination at Hadron Colliders, David Curtin (15 March)
  In the MSSM, like in most models with a dark matter candidate, mass determination is no easy task. To make the LSP stable we impose an R-symmetry, which causes superpartners to be produced in pairs, decaying into SM + 2 LSPs. The presence of two massive invisible particles in the final state makes analysis of these events very challenging. In recent years, the tools available for extracting mass information from these decays have become much more sophisticated. I will give a brief review of mass determination methods for MSSM-type decay chains before moving on to describe very recent developments, which allow us to extract LSP and parent particle masses independently even for single-step decay chains (without losing statistics -- no dodgy MT2-kinks!). References (in order of most to least prominent/important) 0910.3679, 0810.5576, 0711.4526, hep-ph/0304226.
• Anomaly Constraints on Monopoles, Itay Nachshon (29 March)
  We will be going over, Anomaly Constraints on Monopoles and Dyons, By Csaba, Yuri, and John Terning, 1003.0448. With the intention of understanding the context of the paper of electric and magnetic (monopole) charge quantization constraints coming from anomalies. The first part will be to understand the context of the paper: i.e. what was already known about the subject. Then to discuss the paper as time permits.
• Superconformal Anarchic Flavor, Flip Tanedo (5 April)
  Many of us are familiar with anarchic models of flavor within RS where warping converts O(1) bulk masses into hierarchies in the 4D Yukawas. We will discuss a related (and older) idea where the flavor structure comes from the anomalous dimensions of fields flowing past a superconformal fixed point. We will focus on a recent paper By Poland and Simmons-Duffin where a-maximization is used to probe superconformal flavor models that were previously thought to be incalculable. We will only consider the toy models in these papers to understand the relevant model-building techniques. Main paper: 0910.4585. Also see § 2 of hep-ph/0006251.
• Neutrinoless Double Beta Decay, Josh Berger (12 April)
  I will give a review of the theory and some of the experiments pertaining to neutrinoless double beta decay (0νββ). In certain atoms, it is favorable to undergo a beta decay with Δ Z = 2 and emission of two electrons. If the neutrino is not charged under any complex representation of a gauge group, it should be possible to observe such a double beta decay without neutrinos. In order to study this phenomenon, I will first briefly review the QFT of Majorana fermions. I will then review the calculation of the leptonic part of the 0νββ. I will proceed to briefly discuss the relevant nuclear and atomic physics. I will also give an overview of experiments designed to observe 0νββ.
• Multi-Parton Amplitudes in Gauge Theories, Bibhushan Shakya (19 Apr)
  In calculating cross sections with many partons in the final state, the number of Feynman diagrams that need to be considered increases rapidly with the number of particles, and standard techniques of numerical evaluation or algebraic symbolic manipulation soon become useless. This talk reviews some techniques and results that significantly simplify such calculations. We will be covering some subset of the first seven sections of hep-th/0509223.
• Light Gauginos and Conformal Sequestering, Yuhsin Tsai (26 Apr)
  The anomalously light gauginos have been a long lasting problem in many direct and semi-direct gauge mediation models. Recently, Komargodski and Shih (0902.0030) explained the origin of this small mass and connected it to the stability of the pseudo-moduli space (PSM). This means modifying the strucutre of PMS is necessary for a reasonable gaugino mass. We will briefly discuss different proposals that can solve the gaugino mass problem, and focus more on the idea using conformal sequestering given by Hanaki and Ookouchi (1003.5663).

2010 Summer 'Pheno Camp': Dark Matter

CANCELLED. This will be a week-long, in-depth student workshop focusing on dark matter phenomenology, sometime in May/June. Meetings will be roughly 10 - 5pm every day with all participants in the same room.

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)
• Video lectures: Serkan Cabi's collection, Fermilab Academic Lectures, Fermilab VMS, Perimiter Institute Recorded Seminar Archive, CERN Academic Training Lectures, KITP Talks, Newton Institute Programs, IAS SNS recordings.
• Other journal clubs, reading lists: University of Michigan HET Student Journal Club, David E. Kaplan's BSM Reading list, Francesca Borzumati's Collection of Lecture Notes, University of Chicago Theory Reading List, University of Washington Particle Theory Journal Club.
• Blogs often mention recent 'hot research' topics, sometimes with generous portions of personal commentary. Some suggestions: Resonaances (A. Falkowski), A Quantum Diaries Survivor (T. Dorigo), Not Even Wrong (P. Woit).

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 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.