Explore the vast range of titles available.

We correct an overestimation of the production rate of 137 Xe in the DARWIN detector operated at LNGS. This formerly dominant intrinsic background source is now at a level similar to the irreducible background from solar 8 B neutrinos, thus unproblematic at the LNGS depth. The projected half-life sensitivity for the neutrinoless double beta decay ( 0 ν β β ) of 136 Xe improves by 22 % compared to the previously reported number and is now T 1 / 2 0 ν = 3.0 × 10 27 yr (90% C.L.) after 10 years of DARWIN operation.

A prototype of a luminometer, designed for a future e+e- collider detector, and consisting at present of a four-plane module, was tested in the CERN PS accelerator T9 beam. The objective of this beam test was to demonstrate a multi-plane tungsten/silicon operation, to study the development of the electromagnetic shower and to compare it with MC simulations. The Molière radius has been determined to be 24.0 ± 0.6 (stat.) ± 1.5 (syst.) mm using a parametrization of the shower shape. Very good agreement was found between data and a detailed Geant4 simulation.

The future compact linear collider (CLIC) offers a possibility for a rich precision physics programme, in particular in the Higgs sector through the energy staging. This is the first paper addressing the measurement of the standard model Higgs boson decay into two muons at 1.4 TeV CLIC. With respect to similar studies at future linear colliders, this paper includes several novel contributions to the statistical uncertainty of the measurement. The latter includes the equivalent photon approximation employed to describe and interactions whenever the virtuality of the mediated photon is smaller than 4 GeV and realistic forward electron tagging based on energy deposition maps in the forward calorimeters, as well as several processes with the Beamstrahlung photons that results in irreducible contribution to the signal. In addition, coincidence of the Bhabha scattering with the signal and background processes is considered, altering the signal selection efficiency. The study is performed using a fully simulated CLIC_ILD detector model. It is shown that the branching ratio for the Higgs decay into a pair of muons BR( ) times the Higgs production cross-section in WW-fusion can be measured with 38 % statistical accuracy at , assuming an integrated luminosity of 1.5 ab [Formula omitted] with unpolarised beams. If 80 % electron beam polarisation is considered, the statistical uncertainty of the measurement is reduced to 25 %. Systematic uncertainties are negligible in comparison to the statistical uncertainty.

The DARWIN observatory is a proposed next-generation experiment to search for particle dark matter and for the neutrinoless double beta decay of$$^{136}$$136 Xe. Out of its 50 t total natural xenon inventory, 40 t will be the active target of a time projection chamber which thus contains about 3.6 t of$$^{136}$$136 Xe. Here, we show that its projected half-life sensitivity is$$2.4\\times {10}^{27}\\,{\\hbox {year}}$$2.4 × 10 27 year , using a fiducial volume of 5 t of natural xenon and 10 year of operation with a background rate of less than 0.2 events/(t $$\\cdot $$·  year) in the energy region of interest. This sensitivity is based on a detailed Monte Carlo simulation study of the background and event topologies in the large, homogeneous target. DARWIN will be comparable in its science reach to dedicated double beta decay experiments using xenon enriched in$$^{136}$$136 Xe.

We detail the sensitivity of the proposed liquid xenon DARWIN observatory to solar neutrinos via elastic electron scattering. We find that DARWIN will have the potential to measure the fluxes of five solar neutrino components: pp , 7 Be, 13 N, 15 O and pep . The precision of the 13 N, 15 O and pep components is hindered by the double-beta decay of 136 Xe and, thus, would benefit from a depleted target. A high-statistics observation of pp neutrinos would allow us to infer the values of the electroweak mixing angle, sin 2 θ w , and the electron-type neutrino survival probability, P ee , in the electron recoil energy region from a few keV up to 200 keV for the first time, with relative precision of 5% and 4%, respectively, with 10 live years of data and a 30 tonne fiducial volume. An observation of pp and 7 Be neutrinos would constrain the neutrino-inferred solar luminosity down to 0.2%. A combination of all flux measurements would distinguish between the high- (GS98) and low-metallicity (AGS09) solar models with 2.1–2.5 σ significance, independent of external measurements from other experiments or a measurement of 8 B neutrinos through coherent elastic neutrino-nucleus scattering in DARWIN. Finally, we demonstrate that with a depleted target DARWIN may be sensitive to the neutrino capture process of 131 Xe.

Xenon dual-phase time projections chambers (TPCs) have proven to be a successful technology in studying physical phenomena that require low-background conditions. With 40 t of liquid xenon (LXe) in the TPC baseline design, DARWIN will have a high sensitivity for the detection of particle dark matter, neutrinoless double beta decay ( 0 ν β β ), and axion-like particles (ALPs). Although cosmic muons are a source of background that cannot be entirely eliminated, they may be greatly diminished by placing the detector deep underground. In this study, we used Monte Carlo simulations to model the cosmogenic background expected for the DARWIN observatory at four underground laboratories: Laboratori Nazionali del Gran Sasso (LNGS), Sanford Underground Research Facility (SURF), Laboratoire Souterrain de Modane (LSM) and SNOLAB. We present here the results of simulations performed to determine the production rate of 137 Xe, the most crucial isotope in the search for 0 ν β β of 136 Xe. Additionally, we explore the contribution that other muon-induced spallation products, such as other unstable xenon isotopes and tritium, may have on the cosmogenic background.

We correct an overestimation of the production rate of$$^{137}$$137 Xe in the DARWIN detector operated at LNGS. This formerly dominant intrinsic background source is now at a level similar to the irreducible background from solar$$^8$$8 B neutrinos, thus unproblematic at the LNGS depth. The projected half-life sensitivity for the neutrinoless double beta decay ($$0\\nu \\beta \\beta $$0 ν β β ) of$$^{136}$$136 Xe improves by$$22\\%$$22 % compared to the previously reported number and is now$$T^{0\\nu }_{1/2}= {3.0\\times 10^{27}} \\hbox { yr}$$T 1 / 2 0 ν = 3.0 × 10 27 yr (90% C.L.) after 10 years of DARWIN operation.

A measurement is presented of the inclusive neutral current e±p scattering cross section using data collected by the H1 experiment at HERA during the years 2003 to 2007 with proton beam energies Ep of 920, 575, and 460 GeV. The kinematic range of the measurement covers low absolute four-momentum transfers squared, 1.5 GeV2

Journal Article

Share this book

Add to My Shelf