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Cesium bright matter-wave solitons and soliton trainsFeb 08 2019A setup for studying bright matter-wave solitons of a cesium Bose-Einstein condensate (BEC) is presented. Production of a single soliton is demonstrated and dependence of soliton atom number on the interatomic interaction is studied. Formation of soliton ... More

Chiral corrections in electroweak processes with heavy mesonsDec 27 2002The effective theory based on combined chiral and heavy quark symmetry (HHChPT) is applied to D meson decays. The predictions for several flavor changing neutral current rare radiative charm decays are given both in the Standard Model as well as for the ... More

Cesium bright matter-wave solitons and soliton trainsFeb 08 2019Mar 05 2019A study of bright matter-wave solitons of a cesium Bose-Einstein condensate (BEC) is presented. Production of a single soliton is demonstrated and dependence of soliton atom number on the interatomic interaction is investigated. Formation of soliton trains ... More

The case for measuring gamma preciselyDec 30 2010We first review the methods for determining gamma from B->D K decays that appeared after CKM 2008. We then discuss the theoretical errors in gamma extraction. The errors due to neglected D-Dbar and B_{d,s}-Bbar_{d,s} mixing can be avoided by including ... More

Introduction to flavour physicsMar 12 2019Apr 02 2019We give a brief introduction to flavour physics. The first part covers the flavour structure of the Standard Model, how the Kobayashi-Maskawa mechanism is tested and provides examples of searches for new physics using flavour observables, such as meson ... More

Bad-Metallic Behavior of Doped Mott InsulatorsDec 02 2015Dec 28 2016Employing Nernst-Einstein decomposition $\sigma=e^2\chi_c D$ of the conductivity $\sigma$ onto charge susceptibility (compressibility) $\chi_c$ and diffusion constant $D$, we argue that the bad-metallic behavior of $\sigma$ in the regime of high temperatures ... More

Groupoid representations and modules over the convolution algebrasJun 11 2008The classical Serre-Swan's theorem defines a bijective correspondence between vector bundles and finitely generated projective modules over the algebra of continuous functions on some compact Hausdorff topological space. We extend these results to obtain ... More

Introduction to flavour physicsMar 12 2019We give a brief introduction to flavour physics. The first part covers the flavour structure of the Standard Model, how the Kobayashi-Maskawa mechanism is tested and provides examples of searches for new physics using flavour observables, such as meson ... More

Top Decays in the Standard Model and BeyondNov 30 2012In these proceedings we explore the possibility of new physics manifesting itself in rare top quark decays. In particular, we adopt an effective theory description of FCNC t -> q V top quark decays and possible deviations from the SM form of tWb vertices ... More

Penguin pollution estimates relevant for phi_2/alpha extractionDec 31 2006Aug 16 2007A review of methods to extract the standard CKM unitarity triangle angle alpha is provided. The sizes of related theoretical errors are reviewed.

Determining alpha and gamma - theoryOct 27 2004In this short review presented at FPCP04, Daegu, Korea, we discuss methods leading to determinations of alpha and gamma with practically no theoretical error. The remaining theoretical errors due to isospin breaking, neglecting of electroweak penguins ... More

Representations of orbifold groupoidsSep 03 2007Oct 11 2007Orbifold groupoids have been recently widely used to represent both effective and ineffective orbifolds. We show that every orbifold groupoid can be faithfully represented on a continuous family of finite dimensional Hilbert spaces. As a consequence we ... More

Bad-Metallic Behavior of Doped Mott InsulatorsDec 02 2015Dec 16 2015Employing Nernst-Einstein decomposition $\sigma=e^2\chi_c D$ of the conductivity $\sigma$ onto charge susceptibility (compressibility) $\chi_c$ and diffusion constant $D$, we argue that the bad-metallic behavior of $\sigma$ in the regime of high temperatures ... More

Predictions for sin 2(beta/phi_1)_eff in b->s penguin dominated modesJul 09 2007Sep 19 2007We provide a review of predictions for sin 2beta_eff in b->s penguin dominated modes based on 1/m_b expansion and/or SU(3) flavor symmetry. The experimental results are consistently lower than the theoretical predictions. In order to interpret whether ... More

Constraints on new physics from top quark decays at high precisionOct 18 2012We study possible theoretical deviations from SM in top quark physics which alter the decay properties of the top quark. Using effective filed theory techniques we parametrize the effects of potential NP of scales well above the electroweak scale in terms ... More

Flipping t tbar asymmetries at the Tevatron and the LHCMay 21 2012We show that the charge asymmetry in t tbar production at the LHC, A_C, and the forward-backward asymmetry at the Tevatron, A_FB, are in general not tightly correlated. They can even have opposite signs, if the underlying new physics (NP) model is general ... More

Dark sectors and enhanced $h\to τμ$ transitionsJan 30 2017LHC searches with $\tau$ leptons in the final state are always inclusive in missing-energy sources. A signal in the flavor-violating Higgs decay search, $h\to\tau\mu$, could therefore equally well be due to a flavor conserving decay, but with an extended ... More

The ultimate theoretical error on gamma from B -> D K decaysAug 26 2013The angle gamma of the standard CKM unitarity triangle can be determined from B -> D K decays with a very small irreducible theoretical error, which is only due to second-order electroweak corrections. We study these contributions and estimate that their ... More

Predictions for b -> ssdbar, ddsbar decays in the SM and with new physicsAug 21 2009The b -> ssdbar and b -> ddsbar decays are highly suppressed in the SM, and are thus good probes of new physics (NP) effects. We discuss in detail the structure of the relevant SM effective Hamiltonian pointing out the presence of nonlocal contributions ... More

Two component dark matterOct 23 2008Apr 21 2009We explain the PAMELA positron excess and the PPB-BETS/ATIC e+ + e- data using a simple two component dark matter model (2DM). The two particle species in the dark matter sector are assumed to be in thermal equilibrium in the early universe. While one ... More

Donor Retention in Online Crowdfunding Communities: A Case Study of DonorsChoose.orgMar 09 2015Online crowdfunding platforms like DonorsChoose.org and Kickstarter allow specific projects to get funded by targeted contributions from a large number of people. Critical for the success of crowdfunding communities is recruitment and continued engagement ... More

Defining and Evaluating Network Communities based on Ground-truthMay 28 2012Nov 06 2012Nodes in real-world networks organize into densely linked communities where edges appear with high concentration among the members of the community. Identifying such communities of nodes has proven to be a challenging task mainly due to a plethora of ... More

Simulating single-coil MRI from the responses of multiple coilsNov 19 2018May 27 2019We convert the information-rich measurements of parallel and phased-array MRI into noisier data that a corresponding single-coil scanner could have taken. Specifically, we replace the responses from multiple receivers with a linear combination that emulates ... More

Similarity of thermodynamic properties of Heisenberg model on triangular and kagome latticesJun 27 2019Derivation of a reduced effective model allows for a unified treatment and discussion of the $J_1$-$J_2$ Heisenberg model on a triangular and kagome lattice. Calculating thermodynamic quantities, i.e. the entropy $s(T)$ and uniform susceptibility $\chi_0(T)$, ... More

Similarity of thermodynamic properties of Heisenberg model on triangular and kagome latticesJun 27 2019Jul 01 2019Derivation of a reduced effective model allows for a unified treatment and discussion of the $J_1$-$J_2$ Heisenberg model on a triangular and kagome lattice. Calculating thermodynamic quantities, i.e. the entropy $s(T)$ and uniform susceptibility $\chi_0(T)$, ... More

On generation of node distributions for meshless PDE discretizationsDec 07 2018Jun 10 2019In this paper we present an algorithm that is able to generate locally regular node layouts with spatially variable nodal density for interiors of arbitrary domains in two, three and higher dimensions. It is demonstrated that the generated node distributions ... More

On the Poisson equation for Metropolis-Hastings chainsNov 23 2015Feb 26 2017This paper defines an approximation scheme for a solution of the Poisson equation of a geometrically ergodic Metropolis-Hastings chain $\Phi$. The approximations give rise to a natural sequence of control variates for the ergodic average $S_k(F)=(1/k)\sum_{i=1}^{k} ... More

Predicting multicellular function through multi-layer tissue networksJul 14 2017Motivation: Understanding functions of proteins in specific human tissues is essential for insights into disease diagnostics and therapeutics, yet prediction of tissue-specific cellular function remains a critical challenge for biomedicine. Results: Here ... More

SNAP: A General Purpose Network Analysis and Graph Mining LibraryJun 24 2016Large networks are becoming a widely used abstraction for studying complex systems in a broad set of disciplines, ranging from social network analysis to molecular biology and neuroscience. Despite an increasing need to analyze and manipulate large networks, ... More

Structure and Overlaps of Communities in NetworksMay 28 2012Sep 25 2012One of the main organizing principles in real-world social, information and technological networks is that of network communities, where sets of nodes organize into densely linked clusters. Even though detection of such communities is of great interest, ... More

Latent Multi-group Membership Graph ModelMay 21 2012We develop the Latent Multi-group Membership Graph (LMMG) model, a model of networks with rich node feature structure. In the LMMG model, each node belongs to multiple groups and each latent group models the occurrence of links as well as the node feature ... More

Asymptotic variance for Random walk Metropolis chains in high dimensions: logarithmic growth via the Poisson equationJul 26 2017Feb 07 2019There are two ways of speeding up MCMC algorithms: (1) construct more complex samplers that use gradient and higher order information about the target and (2) design a control variate to reduce the asymptotic variance. While the efficiency of (1) as a ... More

Multiplicative Attribute Graph Model of Real-World NetworksSep 17 2010Apr 14 2011Large scale real-world network data such as social and information networks are ubiquitous. The study of such social and information networks seeks to find patterns and explain their emergence through tractable models. In most networks, and especially ... More

Pseudo-Casimir force in confined nematic polymersSep 08 2000We investigate the pseudo-Casimir force in a slab of material composed of nematically ordered long polymers. We write the total mesoscopic energy together with the constraint connecting the local density and director fluctuations and evaluate the corresponding ... More

Planetary-Scale Views on an Instant-Messaging NetworkMar 06 2008We present a study of anonymized data capturing a month of high-level communication activities within the whole of the Microsoft Messenger instant-messaging system. We examine characteristics and patterns that emerge from the collective dynamics of large ... More

node2vec: Scalable Feature Learning for NetworksJul 03 2016Prediction tasks over nodes and edges in networks require careful effort in engineering features used by learning algorithms. Recent research in the broader field of representation learning has led to significant progress in automating prediction by learning ... More

Stereo Matching by Training a Convolutional Neural Network to Compare Image PatchesOct 20 2015May 18 2016We present a method for extracting depth information from a rectified image pair. Our approach focuses on the first stage of many stereo algorithms: the matching cost computation. We approach the problem by learning a similarity measure on small image ... More

Computing the Stereo Matching Cost with a Convolutional Neural NetworkSep 15 2014Oct 20 2015We present a method for extracting depth information from a rectified image pair. We train a convolutional neural network to predict how well two image patches match and use it to compute the stereo matching cost. The cost is refined by cross-based cost ... More

Dark Matter attempts for CoGeNT and DAMAJun 30 2011Recently, the CoGeNT collaboration presented a positive signal for an annual modulation in their data set. In light of the long standing annual modulation signal in DAMA/LIBRA, we analyze the compatibility of both of these signal within the hypothesis ... More

Modeling Social Networks with Node Attributes using the Multiplicative Attribute Graph ModelJun 24 2011Networks arising from social, technological and natural domains exhibit rich connectivity patterns and nodes in such networks are often labeled with attributes or features. We address the question of modeling the structure of networks where nodes have ... More

Finite-temperature properties of the extended Heisenberg model on a triangular latticeApr 13 2018We present numerical results for the $J_1$-$J_2$ Heisenberg model on a triangular lattice at finite temperatures $T>0$. In contrast to unfrustrated lattices we reach much lower $T \sim 0.15 J_1$. In static quantities the novel feature is a quite sharp ... More

Asymptotic variance for Random walk Metropolis chains in high dimensions: logarithmic growth via the Poisson equationJul 26 2017Apr 01 2019There are two ways of speeding up MCMC algorithms: (1) construct more complex samplers that use gradient and higher order information about the target and (2) design a control variate to reduce the asymptotic variance. While the efficiency of (1) as a ... More

On generation of node distributions for meshless PDE discretizationsDec 07 2018In this paper we present an algorithm that is able to generate locally regular node layouts with spatially variable nodal density for interiors of arbitrary domains in two, three and higher dimensions. It is demonstrated that the generated node distributions ... More

Tracking the time-evolution of the electron distribution function in Copper by femtosecond broadband optical spectroscopyJul 05 2019Multi-temperature models are nowadays often used to quantify the ultrafast electron-phonon (boson) relaxations and coupling strengths in advanced quantum solids. To test their applicability we study the time evolution of the electron distribution function, ... More

Adaptive Radial Basis Function-generated Finite Differences method for contact problemsNov 26 2018Mar 18 2019This paper proposes an original adaptive refinement framework using Radial Basis Functions-generated Finite Differences method. Node distributions are generated with a Poisson Disk Sampling-based algorithm from a given continuous density function, which ... More

Refined Meshless Local Strong Form solution of Cauchy-Navier equation on an irregular domainFeb 22 2019This paper considers a numerical solution of a linear elasticity problem, namely the Cauchy-Navier equation, using a strong form method based on a local Weighted Least Squares (WLS) approximation. The main advantage of the employed numerical approach, ... More

Asymptotic variance for Random walk Metropolis chains in high dimensions: logarithmic growth via the Poisson equationJul 26 2017Jun 18 2019There are two ways of speeding up MCMC algorithms: (1) construct more complex samplers that use gradient and higher order information about the target and (2) design a control variate to reduce the asymptotic variance. While the efficiency of (1) as a ... More

Similarity of thermodynamic properties of Heisenberg model on triangular and kagome latticesJun 27 2019Jul 02 2019Derivation of a reduced effective model allows for a unified treatment and discussion of the $J_1$-$J_2$ Heisenberg model on a triangular and kagome lattice. Calculating thermodynamic quantities, i.e. the entropy $s(T)$ and uniform susceptibility $\chi_0(T)$, ... More

On the Poisson equation for Metropolis-Hastings chainsNov 23 2015This paper defines an approximation scheme for a solution of the Poisson equation of a geometrically ergodic Metropolis-Hastings chain $\Phi$. The approximations give rise to a natural sequence of control variates for the ergodic average $S_k(F)=(1/k)\sum_{i=1}^{k} ... More

Simulating single-coil MRI from the responses of multiple coilsNov 19 2018Nov 21 2018We convert the information-rich measurements of parallel and phased-array MRI into noisier data that a corresponding single-coil scanner could have taken. Specifically, we replace the responses from multiple receivers with a linear combination that emulates ... More

Adaptive RBF-FD method for contact problemsNov 26 2018This paper proposes an original adaptive refinement framework, which combines the Radial Basis Functions-generated Finite Differences method and its prominent ability to tackle PDEs on scattered nodes without an exact mesh, with a simple nodal positioning ... More

From Amateurs to Connoisseurs: Modeling the Evolution of User Expertise through Online ReviewsMar 18 2013Recommending products to consumers means not only understanding their tastes, but also understanding their level of experience. For example, it would be a mistake to recommend the iconic film Seven Samurai simply because a user enjoys other action movies; ... More

B^\pm -> D K^\pm with direct CP violation in charmDec 01 2012Dec 20 2012We investigate the implications of direct CP violation (CPV) on the determination of the unitarity triangle angle \gamma\ from B -> DK decays. We show that \gamma\ can still be extracted even with the inclusion of direct CPV in charm if (i) at least one ... More

Continuous Flavor Symmetries and the Stability of Asymmetric Dark MatterAug 17 2014Generically, the asymmetric interactions in asymmetric dark matter (ADM) models lead to decaying DM. We show that, for ADM that carries nonzero baryon number, the continuous flavor symmetries that generate the flavor structure in the quark sector also ... More

Nonparametric Multi-group Membership Model for Dynamic NetworksNov 08 2013Relational data-like graphs, networks, and matrices-is often dynamic, where the relational structure evolves over time. A fundamental problem in the analysis of time-varying network data is to extract a summary of the common structure and the dynamics ... More

Discovering Social Circles in Ego NetworksOct 30 2012Jan 10 2013People's personal social networks are big and cluttered, and currently there is no good way to automatically organize them. Social networking sites allow users to manually categorize their friends into social circles (e.g. 'circles' on Google+, and 'lists' ... More

Image Labeling on a Network: Using Social-Network Metadata for Image ClassificationJul 16 2012Large-scale image retrieval benchmarks invariably consist of images from the Web. Many of these benchmarks are derived from online photo sharing networks, like Flickr, which in addition to hosting images also provide a highly interactive social community. ... More

On the Convexity of Latent Social Network InferenceOct 26 2010In many real-world scenarios, it is nearly impossible to collect explicit social network data. In such cases, whole networks must be inferred from underlying observations. Here, we formulate the problem of inferring latent social networks based on network ... More

Discovering Dark Matter Through Flavor Violation at the LHCJul 04 2011We show that the discovery channel for dark matter (DM) production at colliders can be through flavor violating interactions resulting in a novel signature of a single top and large missing transverse energy. We discuss several examples where the production ... More

The Bursty Dynamics of the Twitter Information NetworkMar 11 2014In online social media systems users are not only posting, consuming, and resharing content, but also creating new and destroying existing connections in the underlying social network. While each of these two types of dynamics has individually been studied ... More

A Simple Number Theoretic ResultJul 28 2012We derive an interesting congruence relation motivated by an Indian Olympiad problem. We give three different proofs of the theorem and mention a few interesting related results.

Two body B decays with isosinglet final states in SCETJan 26 2006Aug 23 2006Expressions for decay amplitudes of B0, B- and Bs mesons to two light pseudoscalar or vector mesons, including isosinglet mesons eta, eta', omega, phi, are obtained using Soft Collinear Effective Theory at LO in 1/mb. These are then used to predict unmeasured ... More

Binomial Symbols and Prime ModuliSep 07 2012We try to improve a problem asked in an Indian Math Olympiad. We give a brief overview of the work done in Saikia and Vogrinc (2011) and Saikia and Vogrinc where the authors have found a periodic sequence and the length of its period, all inspired from ... More

Phenomenology of Dark Matter annihilation into a long-lived intermediate stateMar 18 2009Jul 13 2009We propose a scenario where Dark Matter (DM) annihilates into an intermediate state which travels a distance $\lambda \equiv v/\Gamma$ on the order of galactic scales and then decays to Standard Model (SM) particles. The long lifetime disperses the production ... More

Phase behaviour of colloidal assemblies on 2D corrugated substratesApr 24 2012We investigate - with Monte Carlo computer simulations - the phase behaviour of dimeric colloidal molecules on periodic substrates with square symmetry. The molecules are formed in a two-dimensional suspension of like charged colloids subject to periodic ... More

CP Asymmetries in B->K pi, K*pi, rho K DecaysJan 05 2010Mar 31 2010We show that ratios of tree and penguin amplitudes in B-> K*pi and B->rho K are two to three times larger than in B-> K pi. This allows for considerably larger CP asymmetries in the former processes than the 10% asymmetry measured in B0 -> K+pi-. We study ... More

Colloidal ionic complexes on periodic substrates: ground state configurations and pattern switchingFeb 08 2011We theoretically and numerically studied ordering of "colloidal ionic clusters" on periodic substrate potentials as those generated by optical trapping. Each cluster consists of three charged spherical colloids: two negatively and one positively charged. ... More

Goal-setting And Achievement In Activity Tracking Apps: A Case Study Of MyFitnessPalApr 04 2019Activity tracking apps often make use of goals as one of their core motivational tools. There are two critical components to this tool: setting a goal, and subsequently achieving that goal. Despite its crucial role in how a number of prominent self-tracking ... More

Unitarity triangle angles from penguin-dominated B meson decaysMay 01 2011In this time of transition to a new generation of quark flavor experiments we review both the theoretical and the experimental progress on the determination of unitarity triangle angles from penguin-dominated B decays. This summarizes the activities of ... More

Information Diffusion and External Influence in NetworksJun 06 2012Social networks play a fundamental role in the diffusion of information. However, there are two different ways of how information reaches a person in a network. Information reaches us through connections in our social networks, as well as through the ... More

Large-scale analysis of disease pathways in the human interactomeDec 03 2017Discovering disease pathways, which can be defined as sets of proteins associated with a given disease, is an important problem that has the potential to provide clinically actionable insights for disease diagnosis, prognosis, and treatment. Computational ... More

Light quark Yukawa couplings from Higgs kinematicsJun 30 2016Dec 21 2016We show that the normalized Higgs production $p_T$ and $y_h$ distributions are sensitive probes of Higgs couplings to light quarks. For up and/or down quark Yukawa couplings comparable to the SM $b$ quark Yukawa the $\bar u u$ or $\bar d d$ fusion production ... More

I'll Be Back: On the Multiple Lives of Users of a Mobile Activity Tracking ApplicationFeb 25 2018Mobile health applications that track activities, such as exercise, sleep, and diet, are becoming widely used. While these activity tracking applications have the potential to improve our health, user engagement and retention are critical factors for ... More

Anomaly free Froggatt-Nielsen models of flavorJul 23 2019We introduce two anomaly free versions of Froggatt-Nielsen (FN) models, based on either $G_{\rm FN}=U(1)^3$ or $G_{\rm FN}=U(1)$ horizontal symmetries, that generate the SM quark and lepton flavor structures. The structure of these "inverted" FN models ... More

Data Sketching for Faster Training of Machine Learning ModelsJun 05 2019Many machine learning problems reduce to the problem of minimizing an expected risk, defined as the sum of a large number of, often convex, component functions. Iterative gradient methods are popular techniques for the above problems. However, they are ... More

Inductive Representation Learning on Large GraphsJun 07 2017Sep 10 2018Low-dimensional embeddings of nodes in large graphs have proved extremely useful in a variety of prediction tasks, from content recommendation to identifying protein functions. However, most existing approaches require that all nodes in the graph are ... More

Constraints on CP-violating Higgs couplings to the third generationOct 04 2013Nov 27 2013Discovering CP-violating effects in the Higgs sector would constitute an indisputable sign of physics beyond the Standard Model. We derive constraints on the CP-violating Higgs-boson couplings to top and bottom quarks as well as to tau leptons from low-energy ... More

Inferring Networks of Diffusion and InfluenceJun 01 2010Oct 23 2011Information diffusion and virus propagation are fundamental processes taking place in networks. While it is often possible to directly observe when nodes become infected with a virus or adopt the information, observing individual transmissions (i.e., ... More

Prioritizing network communitiesMay 07 2018May 28 2018Uncovering modular structure in networks is fundamental for systems in biology, physics, and engineering. Community detection identifies candidate modules as hypotheses, which then need to be validated through experiments, such as mutagenesis in a biological ... More

Higher-order clustering in networksApr 12 2017Jan 05 2018A fundamental property of complex networks is the tendency for edges to cluster. The extent of the clustering is typically quantified by the clustering coefficient, which is the probability that a length-2 path is closed, i.e., induces a triangle in the ... More

Categorizing User Sessions at PinterestMar 28 2017Oct 25 2017Different users can use a given Internet application in many different ways. The ability to record detailed event logs of user in-application activity allows us to discover ways in which the application is being used. This enables personalization and ... More

Updated bounds on CP asymmetries in $B^0 \to η' K_S$ and $B^0 \to π^0 K_S$Aug 07 2006Oct 27 2006New rate measurements of $B^0$ decays into $\pi^0\pi^0, \pi^0\eta, \pi^0\eta', \eta\eta, \eta\eta', \eta'\eta'$ and $K^+ K^-$ are used in conjunction with flavor SU(3) to constrain the coefficients $S$ and $C$ of $\sin\Delta mt$ and $\cos\Delta mt$ in ... More

Community Detection in Networks with Node AttributesJan 28 2014Community detection algorithms are fundamental tools that allow us to uncover organizational principles in networks. When detecting communities, there are two possible sources of information one can use: the network structure, and the features and attributes ... More

Flavor Violating Higgs DecaysSep 06 2012Aug 14 2015We study a class of nonstandard interactions of the newly discovered 125 GeV Higgs-like resonance that are especially interesting probes of new physics: flavor violating Higgs couplings to leptons and quarks. These interaction can arise in many frameworks ... More

Size of direct CP violation in singly Cabibbo-suppressed D decaysNov 21 2011Sep 16 2015The first experimental evidence for direct CP violation in charm-quark decays has recently been presented by the LHCb collaboration in the difference between the D -> K+ K- and D -> pi+ pi- time-integrated CP asymmetries. We estimate the size of the effects ... More

Review of new physics effects in t-tbar productionJul 26 2011Both CDF and DO report a forward-backward asymmetry in t-tbar production that is above the standard model prediction. We review new physics models that can give a large forward backward asymmetry in t-tbar production at the Tevatron and the constraints ... More

Predicting Dynamic Embedding Trajectory in Temporal Interaction NetworksAug 03 2019Modeling sequential interactions between users and items/products is crucial in domains such as e-commerce, social networking, and education. Representation learning presents an attractive opportunity to model the dynamic evolution of users and items, ... More

Diachronic Word Embeddings Reveal Statistical Laws of Semantic ChangeMay 30 2016Sep 26 2016Understanding how words change their meanings over time is key to models of language and cultural evolution, but historical data on meaning is scarce, making theories hard to develop and test. Word embeddings show promise as a diachronic tool, but have ... More

Right-handed Neutrinos and $R(D^{(*)})$Jul 12 2018Mar 13 2019We explore scenarios where the $R(D^{(*)})$ anomalies arise from semitauonic decays to a right-handed sterile neutrino. We perform an EFT study of all five simplified models capable of generating at tree-level the lowest dimension electroweak operators ... More

Design principles for super selectivity using multivalent interactionsAug 03 2016Apr 03 2017Multivalent particles have the ability to form multiple bonds to a substrate. Hence, a multivalent interaction can be strong, even if the individual bonds are weak. However, much more interestingly, multivalency greatly increases the sensitivity of the ... More

How to test for mass degenerate Higgs resonancesJan 02 2013Apr 25 2013The Higgs-like signal observed at the LHC could be due to several mass degenerate resonances. We show that the number of resonances is related to the rank of a "production and decay" matrix, $R_{if}$. Each entry in this matrix contains the observed rate ... More

Learning Attitudes and Attributes from Multi-Aspect ReviewsOct 15 2012Oct 31 2012The majority of online reviews consist of plain-text feedback together with a single numeric score. However, there are multiple dimensions to products and opinions, and understanding the `aspects' that contribute to users' ratings may help us to better ... More

Learning Dynamic Embeddings from Temporal InteractionsDec 06 2018Modeling a sequence of interactions between users and items (e.g., products, posts, or courses) is crucial in domains such as e-commerce, social networking, and education to predict future interactions. Representation learning presents an attractive solution ... More

Lepton flavor universality violation without new sources of quark flavor violationApr 20 2017Jan 12 2018We show that new physics models without new flavor violating interactions can explain the recent anomalies in the $b\to s\ell^+\ell^-$ transitions. The $b\to s\ell^+\ell^-$ arises from a $Z'$ penguin which automatically predicts the $V-A$ structure for ... More

Predicting Positive and Negative Links in Online Social NetworksMar 11 2010We study online social networks in which relationships can be either positive (indicating relations such as friendship) or negative (indicating relations such as opposition or antagonism). Such a mix of positive and negative links arise in a variety of ... More

Global interpretation of direct Dark Matter searches after CDMS-II resultsDec 22 2009Mar 02 2010We perform a global fit to data from Dark Matter (DM) direct detection experiments, including the recent CDMS-II results. We discuss possible interpretations of the DAMA annual modulation signal in terms of spin-independent and spin-dependent DM-nucleus ... More

B-->pi and B-->K transitions in standard and quenched chiral perturbation theoryOct 25 2002Feb 14 2003We study the effects of chiral logs on the heavy-->light pseudoscalar meson transition form factors by using standard and quenched chiral perturbation theory combined with the static heavy quark limit. The resulting expressions are used to indicate the ... More

Inferring Networks of Substitutable and Complementary ProductsJun 29 2015In a modern recommender system, it is important to understand how products relate to each other. For example, while a user is looking for mobile phones, it might make sense to recommend other phones, but once they buy a phone, we might instead want to ... More

Smoking Guns for On-Shell New Physics at the LHCSep 09 2008Using Tevatron bounds we derive upper limits on the LHC Higgs production rate under the assumption that no beyond the Standard Model (BSM) particles are being produced near their mass shell. A violation of these limits would constitute a smoking gun for ... More

Photoinduced Fano-resonance of coherent phonons in zincNov 02 2006Utilizing femtosecond optical pump-probe technique, we have studied transient Fano-resonance in zinc. At high excitation levels the Fourier spectrum of the coherent E$_{2g}$ phonon exhibits strongly asymmetric line shape, which is well modeled by the ... More