Piano Honors Recital, April 16, 1987

This is the concert program of the Piano Honors Recital on Thursday, April 16, 1987 at 12:30 p.m., at the Concert Hall, 855 Commonwealth Avenue. Works performed were Toccata in G major, BWV 916 by Johann Sebastian Bach, Sonata in D major, K. 430 by Domenico Scarlatti, Sonata in D minor, K. 9 by D. Scarlatti, SOnata in A major, K. 113 by A. Scarlatti, Sonata in A major, Op. 2, No. 2 by Ludwig van Beethoven, Valses nobles et sentimentales by Maurice Ravel, and Tarantella by Franz Liszt. Digitization for Boston University Concert Programs was supported by the Boston University Humanities Library Endowed Fund

A Simpler Strong Refutation of Random k-XOR

Strong refutation of random CSPs is a fundamental question in theoretical computer science that has received particular attention due to the long-standing gap between the information-theoretic limit and the computational limit. This gap is recently bridged by Raghavendra, Rao and Schramm where they study sub-exponential algorithms for the regime between the two limits. In this work, we take a simpler approach to their algorithms and analyses

New Physics Signatures in Kaon Decays

Kaon physics provides a unique opportunity to identify new flavour and CP violating interactions beyond the Standard Model (SM). In the SM, implied by the hierarchical structure of the CKM matrix and the GIM mechanism, flavour changing neutral current processes are most strongly suppressed in the kaon sector while the suppression is much less effective in the B meson systems. Thus their theoretical cleanness makes rare K decays, in particular the K -> pi nu anti-nu system, extremely well suited to look for deviations from their tiny SM values. Despite the increasingly stringent constraints on new physics from direct search experiments as well as indirect searches in B meson decays, large enhancements of both K^+ -> pi^+ nu anti-nu and K_L -> pi^0 nu anti-nu are still possible, and deviations from the SM could be observed even for a multi-TeV new physics scale. In addition the correlation betweeen the charged and neutral K -> pi nu anti-nu modes provides insight on the new physics operator structure in K^0 - anti-K^0 mixing and its interplay with rare K decays. Useful model-discriminating correlations exist also in the K_L -> pi^0 l^+ l^- system. Finally the K -> l nu decays provide a clean test of lepton universality and place constraints on new physics complementary to the ones obtained from the searches for charged lepton flavour violating decays.Comment: 10 pages, 7 figures. Proceedings for KAON13 - 2013 Kaon Physics International Conference at the University of Michigan, Ann Arbor, April 29-May 1 201

Spin-controlled Mott-Hubbard bands in LaMnO_3 probed by optical ellipsometry

Spectral ellipsometry has been used to determine the dielectric function of an untwinned crystal of LaMnO_3 in the spectral range 0.5-5.6 eV at temperatures 50 K < T < 300 K. A pronounced redistribution of spectral weight is found at the Neel temperature T_N = 140 K. The anisotropy of the spectral weight transfer matches the magnetic ordering pattern. A superexchange model quantitatively describes spectral weight transfer induced by spin correlations. This analysis implies that the lowest-energy transitions around 2 eV are intersite d-d transitions, and that LaMnO_3 is a Mott-Hubbard insulator.Comment: 4 pages, 4 figure

Atmospheric leptons, the search for a prompt component

The flux of high-energy (>GeV) neutrinos consists primarily of those produced by cosmic-ray interactions in the atmosphere. The contribution from extraterrestrial sources is still unknown. Current limits suggest that the observed spectrum is dominated by atmospheric neutrinos up to at least 100 TeV. The contribution of charmed hadrons to the flux of atmospheric neutrinos is important in the context of the search for astrophysical neutrinos because the spectrum of such "prompt" neutrinos is harder than that of "conventional" neutrinos from decay of pions and kaons. The prompt component therefore becomes increasingly important as energy increases. This paper reviews the status of the search for prompt muons and neutrinos with emphasis on the complementary aspects of muons, electron neutrinos and muon neutrinos