COMPASS Results on Transverse Single-Spin Asymmetries

New results on single spin asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarised LiD target are presented. The data were taken in the years 2002, 2003 and 2004 with the COMPASS spectrometer using the muon beam of the CERN SPS at 160 GeV/c. Preliminary results are given for the Sivers asymmetry and for all the three ``quark polarimeters'' presently used in COMPASS to measure the transversity distributions. The Collins and the Sivers asymmetries for charged hadrons turn out to be compatible with zero, within the small (~1%) statistical errors, at variance with the results from HERMES on a transversely polarised proton target. Similar results have been obtained for the two hadron asymmetries and for the Lambda polarisation. First attempts to describe the Collins and the Sivers asymmetries measured by COMPASS and HERMES allow to give a consistent picture of these transverse spin effects.Comment: To appear in the proceedings of Advanced Studies Institute: Symmetries And Spin (SPIN-Praha-2006), 19-26 Jul 2006, Prague, Czech Republi

Demolition by Neglect: Repairing Buildings by Repairing Legislation

One of the biggest problems today facing communities with historic preservation ordinances is delinquent owners who don’t have the will or the finances to maintain their historic properties and landmarks. Historic preservation law plays an important role in building a sense of patriotism and community togetherness, fostering education and providing incentives for aesthetically pleasing architecture. When residents can identify with a community, this creates a dialogue and sense of belonging. There are also environmental and psychological impacts of preserving old buildings, since human beings are positively affected by their surroundings when they feel a sense of place. When buildings in a historic district fall prey to \u27demolition by neglect,\u27 meaning that the owners allow their property to reach a state of deterioration, the entire sense of community can be lost

COMPASS results on Collins and Sivers asymmetries for charged hadrons

The study of transverse spin and transverse momentum effects is an important part of the scientific program of COMPASS, a fixed target experiment at the CERN SPS taking data since 2002. The studies are carried on by measuring the hadrons produced in deep inelastic scattering (DIS) of 160 GeV/c muons off different targets. Among the possible asymmetries in the hadron azimuthal distributions, particularly interesting are the Collins and Sivers asymmetries which the COMPASS Collaboration has measured using transversely polarised deuteron and proton targets. The new results for charged pions and kaons obtained from the 2010 run with a transversely polarised proton target are presented.Comment: presented at: SPIN2012, 20th International Spin Physics Symposium, Dubna, Russia, 17-23 September, 201

Loop amplitudes in maximal supergravity with manifest supersymmetry

We present a description for amplitude diagrams in maximal supergravities obtained by dimensional reduction from D=11, derived from a field theory point of view using the pure spinor formalism. The advantages of this approach are the manifest supersymmetry present in the formalism, and the limited number of interaction terms in the action. Furthermore, we investigate the conditions set by this description in order for amplitudes in maximal supergravity to be finite in the ultraviolet limit. Typically, there is an upper limit to the dimension, set by the loop order, which for an arbitrary number of loops is no larger than two. In four dimensions, the non-renormalisation power of the formalism fails for the 7-loop contribution to the 4-point amplitude, all of which is in clear agreement with previous work.Comment: 53 pp. v2: refs. adde

Introduction

Publication within the project “The V4 towards migration challenges in Europe. An analysis and recommendations” is financed by Visegrad Fund

Modeling the angular correlation function and its full covariance in Photometric Galaxy Surveys

Near future cosmology will see the advent of wide area photometric galaxy surveys, like the Dark Energy Survey (DES), that extent to high redshifts (z ~ 1 - 2) but with poor radial distance resolution. In such cases splitting the data into redshift bins and using the angular correlation function $w(\theta)$, or the $C_{\ell}$ power spectrum, will become the standard approach to extract cosmological information or to study the nature of dark energy through the Baryon Acoustic Oscillations (BAO) probe. In this work we present a detailed model for $w(\theta)$ at large scales as a function of redshift and bin width, including all relevant effects, namely nonlinear gravitational clustering, bias, redshift space distortions and photo-z uncertainties. We also present a model for the full covariance matrix characterizing the angular correlation measurements, that takes into account the same effects as for $w(\theta)$ and also the possibility of a shot-noise component and partial sky coverage. Provided with a large volume N-body simulation from the MICE collaboration we built several ensembles of mock redshift bins with a sky coverage and depth typical of forthcoming photometric surveys. The model for the angular correlation and the one for the covariance matrix agree remarkably well with the mock measurements in all configurations. The prospects for a full shape analysis of $w(\theta)$ at BAO scales in forthcoming photometric surveys such as DES are thus very encouraging.Comment: 23 pages, 21 figures Revised version accepted by MNRAS. Description of mocks re-structured. Mocks including redshift distortions and Photo-z publicly available at http://www.ice.cat/mic