119203961
Nonparametric regression using the concept of minimum energy
It has recently been shown that an unbinned distance-based statistic, the energy, can be used to construct an extremely powerful nonparametric multivariate two sample goodness-of-fit test. An extension to this method that makes it possible to perform nonparametric regression using multiple multivariate data sets is presented in this paper. The technique, which is based on the concept of minimizing the energy of the system, permits determination of parameters of interest without the need for parametric expressions of the parent distributions of the data sets. The application and performance of this new method is discussed in the context of some simple example analyses.
117676442
An Ad-Hoc Method for Obtaining chi**2 Values from Unbinned Maximum Likelihood Fits
A common goal in an experimental physics analysis is to extract information from a reaction with multi-dimensional kinematics. The preferred method for such a task is typically the unbinned maximum likelihood method. In fits using this method, the likelihood is a goodness-of-fit quantity in that it effectively discriminates between available hypotheses; however, it does not provide any information as to how well the best hypothesis describes the data. 
In this paper, we present an {\em ad-hoc} procedure for obtaining chi**2/n.d.f. values from unbinned maximum likelihood fits. This method does not require binning the data, making it very applicable to multi-dimensional problems.
118508186
Time-integrated measurements and prospects for the CKM angle gamma at LHCb
The status and prospects of time-integrated measurements of the CKM angle gamma at LHCb, the LHC's dedicated flavor physics experiment, are reviewed. Yields obtained from early data taking are presented and extrapolations are made to estimate what can be expected to be obtained from the 2011 data. The conclusions drawn from these extrapolations are that LHCb will produce the world's best measurement of gamma by the end of 2011 and that the long-term outlook is excellent.
18677949
Separating Signals from Non-Interfering Backgrounds using Probabilistic Event Weightings
A common situation in experimental physics is to have a signal which can not be separated from a non-interfering background through the use of any cut. In this paper, we describe a procedure for determining, on an event-by-event basis, a quality factor (Q-factor) that a given event originated from the signal distribution. This Q-factor can then be used as an event weight in subsequent analysis procedures, allowing one to more directly access the true spectrum of the signal.
118830218
Prospects for the measurement of the unitarity triangle angle gamma from B-0 -> DK+pi(-) decays
The potential for a precise measurement of the unitarity triangle angle gamma in future experiments from the decay B-0 -> DK*0 is well known. It has recently been suggested that the sensitivity can be significantly enhanced by analyzing the B-0 -> DK+pi(-) Dalitz plot to extract amplitudes relative to those of the flavor-specific decay B-0 -> D2*-K+. An extension to this method which includes the case where the neutral D meson is reconstructed in suppressed final states is presented. The sensitivity to gamma is estimated using this method and compared to that obtained using the B-0 -> DK*0 decay alone. Experimental effects, such as background contamination, are also considered. This approach appears to be a highly attractive addition to the family of methods that can be used to determine gamma.
118648061
ObservingCPviolation in many-body decays
It is well known that observing $CP$ violation in many-body decays could provide strong evidence for physics beyond the standard model. Many searches have been carried out; however, no $5\ensuremath{\sigma}$ evidence for $CP$ violation has yet been found in these types of decays. A novel model-independent method for observing $CP$ violation in many-body decays is presented in this paper. It is shown that the sensitivity of this method is significantly larger than those used to-date.
119159946
Inflating with Large Effective Fields
We re-examine large scalar fields within effective field theory, in particular focussing on the issues raised by their use in inflationary models (as suggested by BICEP2 to obtain primordial tensor modes). We argue that when the large-field and low-energy regimes coincide the scalar dynamics is most effectively described in terms of an asymptotic large-field expansion whose form can be dictated by approximate symmetries, which also help control the size of quantum corrections. We discuss several possible symmetries that can achieve this, including pseudo-Goldstone inflatons characterized by a coset G/H (based on abelian and non-abelian, compact and non-compact symmetries), as well as symmetries that are intrinsically higher dimensional. Besides the usual trigonometric potentials of Natural Inflation we also find in this way simple large-field power laws (like V ∝ φ{sup 2}) and exponential potentials, V(φ) = ∑{sub k}V{sub x}e{sup −kφ/M}. Both of these can describe the data well and give slow-roll inflation for large fields without the need for a precise balancing of terms in the potential. The exponential potentials achieve large r through the limit |η| || e and so predict r ≅ (8/3)(1-n{sub s}); consequently n{sub s} ≅ 0.96 gives r ≅ 0.11 but not much larger (and so could be ruled out as measurements on r and n{sub s} improve).more » We examine the naturalness issues for these models and give simple examples where symmetries protect these forms, using both pseudo-Goldstone inflatons (with non-abelian non-compact shift symmetries following familiar techniques from chiral perturbation theory) and extra-dimensional models.« less
118294173
A measurement of the inclusive branching ratio for $b o sgamma$ with the ALEPH detector at LEP
118827257
Who you gonna call? Runaway ghosts, higher derivatives and time-dependence in EFTs
A bstractWe briefly review the formulation of effective field theories (EFTs) in timedependent situations, with particular attention paid to their domain of validity. Our main interest is the extent to which solutions of the EFT capture the dynamics of the full theory. For a simple model we show by explicit calculation that the low-energy action obtained from a sensible UV completion need not take the restrictive form required to obtain only secondorder field equations, and we clarify why runaway solutions are nevertheless typically not a problem for the EFT. Although our results will not be surprising to many, to our knowledge they are only mentioned tangentially in the EFT literature, which (with a few exceptions) largely addresses time-independent situations.
117248378
Accidental Supersymmetry and the Naturalness of Codimension-2 Branes
This thesis addresses two separate naturalness issues which generically come to bear on physical theories with large extra dimensions, and so a gravity scale much lower than the Planck scale. The first is related to the observed stability of the proton, wherein we determine the relevant constraints on an additional gauge boson which conserves baryon number. Although several such proposals have been previously considered, our analysis is distinctive in its interest in lighter gauge boson masses (which naturally arise in such models), and in its focus on the dependence of constraints due to kinetic mixing effects. The second is related to the main purpose of large extra dimensions—namely, to address the smallness of the observed vacuum energy—wherein we compute the leading-order quantum corrections to the four-dimensional (4D) vacuum energy resulting from loops of extradimensional fields. We compute the contributions from bulk scalars (spin 0), fermions (spin 12 ), and gauge fields (spin 1) in a flux-stabilized, spheroidal extra-dimensional geometry whose rugbyball shape is due to two codimension-2 branes—one at each pole. (We also obtain the corresponding beta functions for both bulk and brane operators.) These results are then combined to obtain the net contribution from various multiplets in the context of a particular supersymmetric extra-dimensional model that has been shown to give a vanishing result for the 4D vacuum energy at the classical level. Surprisingly, we find that supersymmetry can be preserved dynamically at one loop in the case of identical branes, without arranging any particular relationship between the brane parameters. Perturbing away from the case of identical branes is shown to give a positive 1-loop contribution to the 4D vacuum energy whose size is set by the radius of the extra dimensions.
118732841
Running with rugby balls: bulk renormalization of codimension-2 branes
A bstractWe compute how one-loop bulk effects renormalize both bulk and brane effective interactions for geometries sourced by codimension-two branes. We do so by explicitly integrating out spin-zero, -half and -one particles in 6-dimensional Einstein-Maxwell-Scalar theories compactified to 4 dimensions on a flux-stabilized 2D geometry. (Our methods apply equally well for D dimensions compactified to D − 2 dimensions, although our explicit formulae do not capture all divergences when D > 6.) The renormalization of bulk interactions are independent of the boundary conditions assumed at the brane locations, and reproduce standard heat-kernel calculations. Boundary conditions at any particular brane do affect how bulk loops renormalize this brane’s effective action, but not the renormalization of other distant branes. Although we explicitly compute our loops using a rugby ball geometry, because we follow only UV effects our results apply more generally to any geometry containing codimension-two sources with conical singularities. Our results have a variety of uses, including calculating the UV sensitivity of one-loop vacuum energy seen by observers localized on the brane. We show how these one-loop effects combine in a surprising way with bulk back-reaction to give the complete low-energy effective cosmological constant, and comment on the relevance of this calculation to proposed applications of codimension-two 6D models to solutions of the hierarchy and cosmological constant problems.