Joint Theory Seminar
Speaker: Peter Graham
Host: Mark Luty Room: 432 PHY
Title: Observing the Dimensionality of Our Parent Vacuum Abstract: It seems generic to have vacua with lower dimensionality than ours. We consider the possibility that the observable universe originated in a transition from one of these vacua. Such a universe has anisotropic spatial curvature. This may be directly observable through its late-time effects on the CMB if the last period of slow-roll inflation was not too long. These affect the entire sky, leading to correlations which persist up to the highest CMB multipoles, thus allowing a conclusive detection above cosmic variance. Further, this anisotropic curvature causes different dimensions to expand at different rates. This leads to other potentially observable signals including a quadrupolar anisotropy in the CMB which limits the size of the curvature. Conversely, if isotropic curvature is observed it may be evidence that our parent vacuum was at least 3+1 dimensional. Such signals could reveal our history of decompactification, providing evidence for the existence of vastly different vacua.
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High-Energy Seminars
Time:
9:10am - 10:10am
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Yes - 1 day 8 hour 0 minutes before start
Description:
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High-Energy Seminars
Time:
5:00am - 6:00am
Description:
Title: The Power of Spin Correlations: from B-decays to Higgs and Beyond at the LHC
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High-Energy Seminars
Time:
6:30am - 7:30am
Description:
Joint Theory Seminar
Speaker: Takemichi Okui (FSU)
Host: Spencer Chang
Room: 432 PHY
Title: Flavorful Gravity Mediation
Abstract: We present a complete, viable model of gravity-mediated supersymmetry breaking that is safe from all flavor constraints. The central new idea is to employ a supersymmetry breaking sector without singlets, but with D-terms comparable to F-terms, causing supersymmetry breaking to be dominantly communicated through \UR-symmetric operators. We construct a visible sector that is an extension of the MSSM where an accidental \UR-symmetry emerges naturally. Gauginos acquire Dirac masses from gravity-mediated D-terms, and tiny Majorana masses from anomaly-mediated contributions. Contributions to soft breaking scalar (mass)2 arise from flavor-arbitrary gravity-induced F-terms plus one-loop finite flavor-blind contributions from Dirac gaugino masses. Renormalization group evolution of the gluino causes it to naturally increase nearly an order of magnitude larger than the squark masses. This hierarchy, combined with an accidentially \UR-symmetric visible sector, nearly eliminates all flavor violation constraints on the model. If we also freely tune couplings and phases within the modest range 0.1-1, while maintaining nearly flavor-anarchic Planck-suppression contributions, we find our model to be safe from DmK, eK, and m\ra e lepton flavor violation. Dangerous \UR-violating <html>Kähler</html> operators in the Higgs sector are eliminated through a new gauged \UX symmetry that is spontaneously broken with electroweak symmetry breaking. Kinetic mixing between \UX and \UY is present with loop-suppressed (but log-enhanced) size e. The Z associated with this \UX has very peculiar couplings - it has order one strength to Higgs doublets and approximately e strength to hypercharge. The Z could be remarkably light and yet have escaped direct and indirect detection.
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High-Energy Seminars
Time:
9:10am - 10:10am
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Yes - 1 day 8 hour 0 minutes before start
Description:
HE Seminar
Mariangela Lisanti (Stanford University)
Host: Spencer Chang
Title: Dark Matter Cartography: Mapping the Universe's Missing Matter
Room: 416 PHY
Abstract: The XENON100 and CRESST experiments will directly test the inelastic dark matter explanation for DAMA's 8.9? sigma anomaly. This article discusses how predictions for direct detection experiments depend on uncertainties in quenching factor measurements, the dark matter interaction with the Standard Model and the halo velocity distribution. When these uncertainties are accounted for, an order of magnitude variation is found in the number of expected events at CRESST and XENON100.
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High-Energy Seminars
Time:
6:30am - 7:30am
Description:
Joint Theory Seminar
Speaker: Chris Lee
Title: Jets in SCET
Host: Markus Luty
Room: 432 PHY
Abstract: Jet shapes are weighted sums over the four-momenta of the constituents of a jet and reveal details of its internal structure, potentially allowing discrimination of its partonic origin. In this work we make predictions for quark and gluon jet shape distributions in N-jet final states in e+e- collisions, defined with a cone or recombination algorithm, where we measure some jet shape observable on a subset of these jets. Using the framework of Soft-Collinear Effective Theory, we prove a factorization theorem for jet shape distributions and demonstrate the consistent renormalization-group running of the functions in the factorization theorem for any number of measured and unmeasured jets, any number of quark and gluon jets, and any angular size R of the jets, as long as R is much smaller than the angular separation between jets. We calculate the jet and soft functions for angularity jet shapes \tau_a to one-loop order (O(alpha_s)) and resum a subset of the large logarithms of \tau_a needed for next-to-leading logarithmic (NLL) accuracy for both cone and kT-type jets. We compare our predictions for the resummed \tau_a distribution of a quark or a gluon jet produced in a 3-jet final state in e+e- annihilation to the output of a Monte Carlo event generator and find that the dependence on a and R is very similar.
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High-Energy Seminars
Time:
9:10am - 10:10am
Send Reminder:
Yes - 1 day 8 hour 0 minutes before start
Description:
HE Seminar
Speaker:
Title:
Host:
Room: 416
User:
High-Energy Seminars
Time:
6:30am - 7:30am
Description:
Joint Theory Seminar
Speaker: Matt Reece (Princeton Univ)
Title:The QCD Strings of Randall-Sundrum Models
Host: Hsin-Chia Cheng
Room: 432 PHY
User:
High-Energy Seminars
Time:
9:10am - 10:10am
Send Reminder:
Yes - 1 day 8 hour 0 minutes before start
Description:
HE Seminar
Speaker: KC Kong (SLAC)
Title: TBA
Host: Luty
Room: 416
6:30am» Joint Theory Seminar: Peter Graham