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V. Adler

Publications and source records attributed to V. Adler.

7 recordsLinked to original sources
arXiv2026

Evidence for parity violation in gravitational fields

Discrete symmetries in gravity have only been tested for low energy, non-relativistic matter, confirming the perfectly symmetric general relativity. A hint for high energy $\cal{CP}$ violation in gravitational fields has recently been found in the HERA Compton polarimeter's two spectra, measured with electron and positron beams. Here we report results of the analysis of the same polarimeter's 314896 spectra, acquired during 2004--2007 and tagged by laser polarization states allowing the separation of charge ($\cal C$) and space parity ($\cal P$) contributions. The measured Compton edge energy asymmetry, induced by the laser helicity flips, is as high as $(4.9\pm0.5)\cdot10^{-5}$ which corresponds to a helicity-dependent difference in the gravitational potentials of $(1.7\pm0.2)\cdot10^{-14}$. In the case of the observed anomalous coupling's energy independence, the spin asymmetric gravity will contribute to the galactic rotational curves. Further analysis and calculations can determine whether the observed magnitude of the gravitational parity violation is sufficient for detaching this famous phenomena from the dark matter theory.

hep-ex↗
arXiv2015

Observation of the rare $B^0_s\toμ^+μ^-$ decay from the combined analysis of CMS and LHCb data

A joint measurement is presented of the branching fractions $B^0_s\toμ^+μ^-$ and $B^0\toμ^+μ^-$ in proton-proton collisions at the LHC by the CMS and LHCb experiments. The data samples were collected in 2011 at a centre-of-mass energy of 7 TeV, and in 2012 at 8 TeV. The combined analysis produces the first observation of the $B^0_s\toμ^+μ^-$ decay, with a statistical significance exceeding six standard deviations, and the best measurement of its branching fraction so far. Furthermore, evidence for the $B^0\toμ^+μ^-$ decay is obtained with a statistical significance of three standard deviations. The branching fraction measurements are statistically compatible with SM predictions and impose stringent constraints on several theories beyond the SM.

hep-ex↗
arXiv2013

Top properties in $t\bar{t}$ events at CMS (includes mass)

Selected results from the following topics are presented: Measurements of several top quark properties are obtained from the CMS data collected in 2011 at a center-of-mass energy of 7 TeV. The results include measurements of the top quark mass, the W helicity in top decays, the top quark charge, and of the $t\bar{t}$ spin correlation and the search for anomalous couplings.

hep-ex↗
arXiv2009

Data Quality Monitoring of the CMS Tracker

The Data Quality Monitoring (DQM) of the Compact Muon Solenoid (CMS) silicon tracking detectors (Tracker) at the Large Hadron Collider (LHC) at CERN is a software based system designed to monitor the detector and reconstruction performance, to identify problems and to certify the collected data for physics analysis. It uses the framework provided by the central CMS DQM as well as tools developed especially for the CMS Tracker DQM. This paper describes aim, framework conditions, tools and work flows of the CMS Tracker DQM and shows examples of its successful use during the recent commissioning phase of the CMS experiment.

physics.ins-det↗
arXiv2007

The design and performance of the ZEUS Micro Vertex detector

In order to extend the tracking acceptance, to improve the primary and secondary vertex reconstruction and thus enhancing the tagging capabilities for short lived particles, the ZEUS experiment at the HERA Collider at DESY installed a silicon strip vertex detector. The barrel part of the detector is a 63 cm long cylinder with silicon sensors arranged around an elliptical beampipe. The forward part consists of four circular shaped disks. In total just over 200k channels are read out using $2.9 {\rm m^2}$ of silicon. In this report a detailed overview of the design and construction of the detector is given and the performance of the completed system is reviewed.

physics.ins-det↗
arXiv2006

Search for RPV Gaugino and Gravitino Production at HERA

In R-parity violating supersymmetry a gaugino can be produced at HERA by the t-channel exchange of a selectron between the beam positron or electron and an initial quark from the beam proton. In the generic MSSM model the gaugino can decay in a cascade into two quarks and an (anti)lepton. For this model a search in the e^{+-}-channel has been performed with the ZEUS detector using combined e^{+-}p-data of L_{int}=121pb^{-1}. No deviations from the Standard Model have been observed and exclusion limits on parameters of the MSSM have been set. Assuming the GMSB model with the gravitino as lightest supersymmetric particle and the neutralino as next-to-lightest supersymmetric particle, the neutralino decays into a gravitino and a high-energy photon. For this model searches have been performed with the H1 detector using e^+p-data of L_{int}=64.3pb^{-1} and e^-p-data of L_{int}=13.5pb^{-1} and with the ZEUS detector using e^+p-data of L_{int}=65.1pb^{-1}. No deviations from the Standard Model have been observed and limits on the selectron and neutralino masses have been set. Additionally, limits on the R-parity violating Yukawa coupling have been derived in the search performed with the H1 detector.

hep-ex↗