U. Husemann

We have searched for Theta+(1540) and Xi(--)(1862) pentaquark candidates in proton-induced reactions on C, Ti, and W targets at midrapidity and square root of s = 41.6 GeV. In 2 x 10(8) inelastic events we find no evidence for narrow (sigma approximately 5 MeV) signals in the Theta+ --> pK0(S) and Xi(--) --> Xi- pi- channels; our 95% C.L. upper limits (UL) for the inclusive production cross section times branching fraction B dsigma/dy/(y approximately 0) are (4-16) mub/N for a Theta+ mass between 1521 and 1555 MeV, and 2.5 mub/N for the Xi(--). The UL of the yield ratio of Theta+/Lambda(1520) < (3-12)% is significantly lower than model predictions. Our UL of B Xi(--)/Xi(1530)0 < 4% is at variance with the results that have provided the first evidence for the Xi(--).

Measurements of the kinematic distributions of J/ψ mesons produced in p–C, p–Ti and p–W collisions at $\sqrt{s}=41.6~\mathrm{GeV}$ in the Feynman-x region −0.34<x F <0.14 and for transverse momentum up to p T =5.4 GeV/c are presented. The x F and p T dependencies of the nuclear suppression parameter, α, are also given. The results are based on 2.4×105 J/ψ mesons reconstructed in both the e + e − and μ + μ − decay channels. The data have been collected by the HERA-B experiment at the HERA proton ring of the DESY laboratory. The measurement explores the negative region of x F for the first time. The average value of α in the measured x F region is 0.981±0.015. The data suggest that the strong nuclear suppression of J/ψ production previously observed at high x F turns into an enhancement at negative x F .

After the discovery of the top quark more than 20 years ago, its properties have been studied in great detail both in production and in decay. Increasingly sophisticated experimental results from the Fermilab Tevatron and from Run 1 and Run 2 of the LHC at CERN are complemented by very precise theoretical predictions in the framework of the standard model of particle physics and beyond. In this article the current status of top-quark physics is reviewed, focusing on experimental results, and a perspective of top-quark physics at the LHC and at future colliders is given.

A study of the angular distributions of leptons from decays of J/ψ's produced in p-C and p-W collisions at $\sqrt{s}=41.6\mbox{~GeV}$ has been performed in the J/ψ Feynman-x region −0.34<x F <0.14 and for J/ψ transverse momenta up to 5.4 GeV/c. The data were collected by the HERA-B experiment at the HERA proton ring of the DESY laboratory. The results, based on a clean selection of 2.3×105 J/ψ's reconstructed in both the e + e − and μ + μ − decay channels, indicate that J/ψ's are produced polarized. The magnitude of the effect is maximal at low p T . For p T >1 GeV/c a significant dependence on the reference frame is found: the polar anisotropy is more pronounced in the Collins-Soper frame and almost vanishes in the helicity frame, where, instead, a significant azimuthal anisotropy arises.

The Collider Detector at Fermilab (CDF) pursues a broad physics program at Fermilab's Tevatron collider. Between Run II commissioning in early 2001 and the end of operations in September 2011, the Tevatron delivered 12 fb-1 of integrated luminosity of p-pbar collisions at sqrt(s)=1.96 TeV. Many physics analyses undertaken by CDF require heavy flavor tagging with large charged particle tracking acceptance. To realize these goals, in 2001 CDF installed eight layers of silicon microstrip detectors around its interaction region. These detectors were designed for 2--5 years of operation, radiation doses up to 2 Mrad (0.02 Gy), and were expected to be replaced in 2004. The sensors were not replaced, and the Tevatron run was extended for several years beyond its design, exposing the sensors and electronics to much higher radiation doses than anticipated. In this paper we describe the operational challenges encountered over the past 10 years of running the CDF silicon detectors, the preventive measures undertaken, and the improvements made along the way to ensure their optimal performance for collecting high quality physics data. In addition, we describe the quantities and methods used to monitor radiation damage in the sensors for optimal performance and summarize the detector performance quantities important to CDF's physics program, including vertex resolution, heavy flavor tagging, and silicon vertex trigger performance.

Particle therapy is a well established clinical treatment of tumors. More than one hundred particle therapy centers are in operation world-wide. The advantage of using hadrons like protons or carbon ions as particles for tumor irradiation is the distinct peak in the depth-dependent energy deposition, which can be exploited to accurately deposit doses in the tumor cells. To guarantee this, high accuracy in monitoring and control of the particle beam is of the utmost importance. Before the particle beam enters the patient, it traverses a monitoring system which has to give fast feedback to the beam control system on position and dose rate of the beam while minimally interacting with the beam. The multi-wire chambers mostly used as beam position monitors have their limitations when a fast response time is required (drift time). Future developments such as MRI-guided ion beam therapy pose additional challenges for the beam monitoring system, such as tolerance of magnetic fields and acoustic noise (vibrations). Solid-state detectors promise to overcome these limitations and the higher resolution they offer can create additional benefits. This article presents the evaluation of an HV-CMOS detector for beam monitoring, provides results from feasibility studies in a therapeutic beam, and summarizes the concepts towards the final large-scale assembly and readout system.

In high-energy particle collisions, the primary collision products usually decay further resulting in tree-like, hierarchical structures with a priori unknown multiplicity. At the stable-particle level all decay products of a collision form permutation invariant sets of final state objects. The analogy to mathematical graphs gives rise to the idea that graph neural networks (GNNs), which naturally resemble these properties, should be best-suited to address many tasks related to high-energy particle physics. In this paper we describe a benchmark test of a typical GNN against neural networks of the well-established deep fully-connected feed-forward architecture. We aim at performing this comparison maximally unbiased in terms of nodes, hidden layers, or trainable parameters of the neural networks under study. As physics case we use the classification of the final state X produced in association with top quark-antiquark pairs in proton-proton collisions at the Large Hadron Collider at CERN, where X stands for a bottom quark-antiquark pair produced either non-resonantly or through the decay of an intermediately produced Z or Higgs boson.

Abstract Nowadays, cancer treatment with ion beam is well established and studied. This method allows to deposit the maximum dose to the tumor and minimize the damage to healthy tissue, due to the Bragg peak of the ion energy deposition near the end of the particle range. During the treatment, it is possible to provide volumetric dose delivery by changing the particle energy (penetration depth) and adjusting the beam position via a magnetic system. For the beam monitoring system, the precise measurement of the beam direction, shape and fluence in real time becomes crucial to provide effective and safe dose delivery to the tumor. Additionally, the system should work for beam intensities up to 10 10 s -1 for protons, be tolerant to 1 MeV neutron equivalent fluences up to 10 15 cm -2 per year and be to tolerant to magnetic fields (for MR-guided ion beam). The studies presented in this article are focused on the application of the HitPix sensor family with counting electronics and frame-based readout for such a beam monitoring system. The HitPix sensors are monolithic pixelated silicon sensors based on HV-CMOS technology and have been developed at the ASIC and Detector Lab (ADL, KIT). Recent measurements with ion beams and a multi-sensor readout as well as future developments are discussed.

The inclusive production cross sections of the strange vector mesons K*0, K*0bar, and phi have been measured in interactions of 920 GeV protons with C, Ti, and W targets with the HERA-B detector at the HERA storage ring. Differential cross sections as a function of rapidity and transverse momentum have been measured in the central rapidity region and for transverse momenta up to pT=3.5 GeV/c. The atomic number dependence is parametrised as sigma(pA) = sigma(pN)*A**alpha, where sigma(pN) is the proton-nucleon cross section. Within the phase space accessible, alpha(K*0) = 0.86+/-0.03, alpha(K*0bar) = 0.87+/-0.03, and alpha(phi) = 0.96+/-0.02. The total proton-nucleon cross sections, determined by extrapolating the differential measurements to full phase space, are sigma(pN->K*0) = 5.06+/-0.54 mb, sigma(pN->K*0bar) = 4.02+/-0.45 mb, and sigma(pN->phi) = 1.17+/-0.11 mb. The Cronin effect is observed for the first time for vector mesons containing strange quarks; compared to the measurements of Cronin et al. for K+- mesons, the measured values of alpha for phi mesons coincide with those of K- mesons for all transverse momenta, while the enhancement for K*0 / K*0bar mesons is smaller.

The inclusive production cross sections of the charmed mesons D0,D+,Ds + and D*+ have been measured in interactions of 920 GeV protons on C, Ti, and W targets with the HERA-B detector at the HERA storage ring. Differential cross sections as a function of transverse momentum and Feynman’s x variable are given for the central rapidity region and for transverse momenta up to pT=3.5 GeV/c. The atomic mass number dependence and the leading to non-leading particle production asymmetries are presented as well.

ψ F < 0.15 is presented.Both µ + µ - and e + e -J/ψ decay channels are observed with an overall statistics of about 15000 χc events, which is by far the largest available sample in pA collisions.The result is Rχ c = 0.188 ± 0.013st +0.024 -0.022 sys averaged over the different materials, when no J/ψ and χc polarisations are considered.The χc1 to χc2 production ratio R12 = Rχ c 1 /Rχ c 2 is measured to be 1.02 ± 0.40, leading to a cross section ratio σ(χ c1 ) σ(χ c2 ) = 0.57 ± 0.23.The dependence of Rχ c on the Feynman-x of the J/ψ, x J/ψ F , and its transverse momentum, p J/ψ T , is studied, as well as its dependence on the atomic number, A, of the target.For the first time, an extensive study of possible biases on Rχ c and R12 due to the dependence of acceptance on the polarization states of J/ψ and χc is performed.By varying the polarisation parameter, λ obs , of all produced J/ψ's by two sigma around the value measured by HERA-B, and considering the maximum variation due to the possible χc1 and χc2 polarisations, it is shown that Rχ c could change by a factor between 1.02 and 1.21 and R12 by a factor between 0.89 and 1.16.

Using data collected by the HERA-B experiment, we have measured the fraction of J/ψ's produced via radiative χc decays in interactions of 920 GeV protons with carbon and titanium targets. We obtained Rχc=0.32±0.06stat±0.04sys for the fraction of J/ψ from χc decays averaged over proton–carbon and proton–titanium collisions. This result is in agreement with previous measurements and is compared with theoretical predictions.

The mid-rapidity (dσpN/dy at y=0) and total (σpN) production cross sections of Jψ mesons are measured in proton–nucleus interactions. Data collected by the HERA-B experiment in interactions of 920 GeV/c protons with carbon, titanium and tungsten targets are used for this analysis. The Jψ mesons are reconstructed by their decay into lepton pairs. The total production cross section obtained is σpNJ/ψ=663±74±46 nb/nucleon. In addition, our result is compared with previous measurements.

In the next generation of collider experiments detectors will be challenged by unprecedented particle fluxes. Thus large detector arrays of highly pixelated detectors with minimal dead area will be required at reasonable costs. Bump-bonding of pixel detectors has been shown to be a major cost-driver. KIT is one of five production centers of the CMS barrel pixel detector for the Phase I Upgrade. In this contribution the SnPb bump-bonding process and the production yield is reported. In parallel to the production of the new CMS pixel detector, several alternatives to the expensive photolithography electroplating/electroless metal deposition technologies are developing. Recent progress and challenges faced in the development of bump-bonding technology based on gold-stud bonding by thin (15 μm) gold wire is presented. This technique allows producing metal bumps with diameters down to 30 μm without using photolithography processes, which are typically required to provide suitable under bump metallization. The short setup time for the bumping process makes gold-stud bump-bonding highly attractive (and affordable) for the flip-chipping of single prototype ICs, which is the main limitation of the current photolithography processes.

A new measurement of the $b\overline{b}$ production cross section in 920 GeV proton-nucleus collisions is presented by the HERA-B Collaboration. The $b\overline{b}$ production is tagged via inclusive bottom quark decays into $J/\ensuremath{\psi}$ mesons by exploiting the longitudinal separation of $J/\ensuremath{\psi}\ensuremath{\rightarrow}{l}^{+}{l}^{\ensuremath{-}}$ decay vertices from the primary proton-nucleus interaction point. Both ${e}^{+}{e}^{\ensuremath{-}}$ and ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ channels are reconstructed for a total of $83\ifmmode\pm\else\textpm\fi{}12$ inclusive $b\ensuremath{\rightarrow}J/\ensuremath{\psi}X$ events found. The combined analysis yields a $b\overline{b}$ to prompt $J/\ensuremath{\psi}$ cross section ratio of $\frac{\ensuremath{\Delta}\ensuremath{\sigma}(b\overline{b})}{\ensuremath{\Delta}{\ensuremath{\sigma}}_{J/\ensuremath{\psi}}}=0.032\ifmmode\pm\else\textpm\fi{}{0.005}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{0.004}_{\mathrm{sys}}$ measured in the ${x}_{F}$ acceptance ($\ensuremath{-}0.35&lt;{x}_{F}&lt;0.15$), extrapolated to $\ensuremath{\sigma}(b\overline{b})=14.9\ifmmode\pm\else\textpm\fi{}{2.2}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{2.4}_{\mathrm{sys}}\text{ }\text{ }\mathrm{\text{nb/nucleon}}$ in the total phase space.

The cross section ratio RJ/ψ=Br(ϒ→l+l−)⋅dσ(ϒ)/dy|y=0/σ(J/ψ) has been measured with the HERA-B spectrometer in fixed-target proton–nucleus collisions at 920 GeV proton beam energy corresponding to a proton–nucleon c.m.s. energy of s=41.6GeV. The combined results for the decay channels ϒ→e+e− and ϒ→μ+μ− yield a ratio RJ/ψ=(9.0±2.1)×10−6. The corresponding ϒ production cross section per nucleon at mid-rapidity (y=0) has been determined to be Br(ϒ→l+l−)⋅dσ(ϒ)/dy|y=0=4.5±1.1pb/nucleon.

We report on a search for the flavor-changing neutral current decay $D^0 \to \mu^+\mu^-$ using $50 \times 10^6$ events recorded with a dimuon trigger in interactions of 920 GeV protons with nuclei by the HERA-B experiment. We find no evidence for such decays and set a 90% confidence level upper limit on the branching fraction $Br(D^0 \to \mu^+\mu^-) <2.0 \times 10^{-6}$.

Inclusive doubly differential cross sections d 2 σ pA /dx F dp 2 as a function of Feynman-x (x F ) and transverse momentum (p T ) for the production of K 0 , Λ and $\bar{\varLambda}$ in proton-nucleus interactions at 920 GeV are presented. The measurements were performed by HERA-B in the negative x F range (−0.12<x F <0.0) and for transverse momenta up to p T =1.6 GeV/c. Results for three target materials: carbon, titanium and tungsten are given. The ratios of production cross sections are presented and discussed. The Cronin effect is clearly observed for all three V 0 species. The atomic number dependence is parameterized as σ pA =σ pN ⋅A α where σ pN is the proton-nucleon cross section. The measured values of α are all near one. The results are compared with EPOS 1.67 and PYTHIA 6.3. EPOS reproduces the data to within ≈20% except at very low transverse momentum.

A detailed description of an original method used to measure the luminosity accumulated by the HERA-B experiment for a data sample taken during the 2002-2003 HERA running period is reported. We show that, with this method, a total luminosity measurement can be achieved with a typical precision, including overall systematic uncertainties, at a level of 5% or better. We also report evidence for the detection of delta-rays generated in the target and comment on the possible use of such delta rays to measure luminosity.

The rich physics program at the high luminosity LHC (HL-LHC) requires all final state particles to be reconstructed with good accuracy.However, it also poses formidable challenge of dealing with very high pileup.Different identification algorithms need to be upgraded along with the detectors to improve the overall event reconstruction in such a hostile collision environment.The new timing device in the proposed CMS detector at the HL-LHC allows for the construction of timing observables at the track-level as well as at the jet-level.This information when given as inputs to the deep neural networks, have a potential to improve the existing algorithms used for heavy flavor (HF) jet tagging.In this paper, the latest developments on the studies for HF jet tagging performance at the HL-LHC are presented.

With the completion of installation and commissioning of the ATLAS detector in 2008, the collaboration has increased its effort focussing on the upgrade of the ATLAS detector devices that should take place in parallel to a luminosity upgrade of the Large Hadron Collider (LHC). The upgrade of the ATLAS tracking detector will be performed in two steps, starting from the insertion of a new innermost pixel silicon layer to a full replacement of the inner tracking devices. Design decisions based on Monte Carlo simulation are necessary within the near future to allow hardware research and development and finally to guarantee a completion of the detector construction until the planned intervention periods.

Monte Carlo (MC) simulations are indispensable tools for top quark physics, both at the current Tevatron collider and the upcoming Large Hadron Collider. In this paper we review how the Tevatron experiments CDF and D0 utilize MC simulations for top quark analyses. We describe the standard MC generators used to simulate top quark pair and single top quark production, followed by a discussion of methods to extract systematic uncertainties of top physics results related to the MC generator choice. The paper also shows the special MC requirements for some example top properties measurements at the Tevatron.

One of the main goals of the HERA-B experiment at DESY in Hamburg, Germany, is to study the properties of B-mesons with the emphasis on CP violation. B-mesons are produced in hadronic interactions of a 920-GeV proton beam with an internal wire target. An effective bunch crossing rate of about 8.5 MHz leads to about 200 charged tracks per event. Therefore, a highly selective and efficient trigger system providing high suppression of background events is required. The HERA-B trigger system consists of four levels. A rate reduction factor of 200 is aimed at by the first-level trigger (FLT). The muon pretrigger system, as a part of the FLT, is a modular system consisting of about 100 large-size VME modules of three different types: the pretrigger link board (PLB), the pretrigger coincidence unit (PCU), and the pretrigger message generator (PMG). The data rate processed by the pretrigger system is about 19.5 GByte/s. The PLBs process digitized hit information in eight independent electronic channels in parallel. Every electronic channel handles 32 bits of hit information received from the front-end driver buffer system. Optical links operating at 800 Mb/s transmit the data after serialization to PCUs, which calculate coincidences using complex programmable logic devices. The PMGs transform this coincidence information into messages for the FLT processors. The concept and design as well as results of the muon pretrigger running at HERA-B are presented.

Measurement of nuclear effects in the production of J/ψ mesons with the HERA-B detector PDF-Abstract Measurement of nuclear effects in the production of J/ψ mesons with the HERA-B detector PDF-Dokument .

This paper describes the muon pretrigger system of the HERA-B experiment. The muon pretrigger is designed to detect track candidates for muons in order to generate seeds for the first level trigger (FLT) search algorithm. Muons provide the cleanest event signature in the large amount of hadronic background. In order to achieve the required precision the muon pretrigger system has to cope with an interaction rate of about 40 MHz at the HERA bunch crossing rate of 10.4 MHz. This results in a total input data rate of about 10 Gbyte/s. A total rate reduction by a factor of 200 is aimed at by the complete FLT, including the pretrigger systems (electromagnetic calorimeter, muon and high-p/sub T/), within at most 12 /spl mu/s.

The HERA-B collaboration has studied the production of charmonium and open charm states in collisions of 920 GeV protons with wire targets of different materials. The acceptance of the HERA-B spectrometer covers negative values of xF up to xF=-0.3 and a broad range in transverse momentum from 0.0 to 4.8 GeV/c. The studies presented in this paper include J/psi differential distributions and the suppression of J/psi production in nuclear media. Furthermore, production cross sections and cross section ratios for open charm mesons are discussed.

We present the design and commissioning of a new multiplicity veto for the HERA-B detector, a fixed-target spectrometer originally designed to study the physics of B mesons in proton-nucleus interactions. The HERA-B trigger is a message-driven multilevel track trigger. The first level trigger (FLT) consists of custom-made electronics, and the higher trigger levels are implemented as PC farms. The multiplicity veto has been designed to reject high-multiplicity events before they enter the trigger chain. A veto signal is generated based on the comparison of the number of photons in part of the HERA-B ring-imaging Cerenkov counter (RICH) with a programmable threshold. The RICH multiplicity veto is a modular system. First the hits in 256 detector channels are summed by base sum cards (BSC), then FED sum cards (FSC) sum the subtotals of up to eight BSCs. Finally, the veto board (VB) takes the veto decision based on the sum of up to 14 FSCs. The RICH multiplicity veto has been successfully installed and commissioned in HERA-B. The measured veto efficiency is (99.9991/spl plusmn/0.0001)%, and the system is used in the routine data-taking of the HERA-B experiment.

Measurements of differential cross sections for top quark-antiquark production are presented as a function of kinematic variables, jet multiplicities, and event-level observables. The measurements are based on proton-protoncollision data recorded with the CMS detector during Run I of the CERN Large Hadron Collider at center-of-mass energies of7 TeV and 8 TeV. Presented at EPS-HEP 2015 European Physical Society Conference on High Energy Physics 2015 Measurement of differential cross sections in top pair production with the CMS detector Ulrich Husemann∗ on behalf of the CMS Collaboration Karlsruhe Institute of Technology Institut fur Experimentelle Kernphysik 76131 Karlsruhe, Germany E-mail: ulrich.husemann@kit.edu Measurements of differential cross sections for top quark-antiquark production are presented as a function of kinematic variables, jet multiplicities, and event-level observables. The measurements are based on proton-proton collision data recorded with the CMS detector during Run I of the CERN Large Hadron Collider at center-of-mass energies of 7 TeV and 8 TeV. The European Physical Society Conference on High Energy Physics 22-29 July 2015 Vienna, Austria

While the tracking detectors of the ATLAS and CMS experiments have shown excellent performance in Run 1 of LHC data taking, and are expected to continue to do so during LHC operation at design luminosity, both experiments will have to exchange their tracking systems when the LHC is upgraded to the high-luminosity LHC (HL-LHC) around the year 2024. The new tracking systems need to operate in an environment in which both the hit densities and the radiation damage will be about an order of magnitude higher than today. In addition, the new trackers need to contribute to the first level trigger in order to maintain a high data-taking efficiency for the interesting processes. Novel detector technologies have to be developed to meet these very challenging goals. The German groups active in the upgrades of the ATLAS and CMS tracking systems have formed a collaborative "Project on Enabling Technologies for Silicon Microstrip Tracking Detectors at the HL-LHC" (PETTL), which was supported by the Helmholtz Alliance "Physics at the Terascale" during the years 2013 and 2014. The aim of the project was to share experience and to work together on key areas of mutual interest during the R&amp;D phase of these upgrades. The project concentrated on five areas, namely exchange of experience, radiation hardness of silicon sensors, low mass system design, automated precision assembly procedures, and irradiations. This report summarizes the main achievements.

Measurements of differential cross sections for top quark-antiquark production are presented as a function of kinematic variables, jet multiplicities, and event-level observables.The measurements are based on proton-proton collision data recorded with the CMS detector during Run I of the CERN Large Hadron Collider at center-of-mass energies of 7 TeV and 8 TeV.

Inhalte der 11. Online-Vorlesung: Paulis Neutrino-Postulat, Experimente zu Neutrino-Entdeckung und Helizitat, Entdeckung von Myon- und Tau-Neutrino, Homestake-Experiment, Entdeckung von Neutrino-Oszillationen, Neutrino-Oszillationen, PMNS-Matrix, Oszillationsamplitude, Formalismus der Zwei-Flavor-Oszillationen, Dirac- und Majorana-Neutrinos, Erweiterung des Standardmodells um Neutrinomassen, Seesaw-Mechanismus.

Inhalte der 10. Online-Vorlesung: Wiederholung BEH-Mechanismus, Higgs-Kopplungen, longitudinale WW-Streuung, Gultigkeit sbereich des Standardmodells, Perturbativitats- und Stabilitatsschranken, Higgs-Produktion und -Zerfall am LHC, nutzbare Higgs-Kanale, direkte Higgs-Suchen bei LEP und am Tevatron, indirekte Schranken auf die Higgs-Masse aus Prazisionsdaten.

Inhalte der 13. Online-Vorlesung: Supersymmetrie, Teilchen und ihre Superpartner, SUSY-Brechung: MSUGRA, GMSB, AMSB, SUSY und Feinjustierung, Vereinigung der Eichkopplunge, R-Paritat, SUSY und Dunkle Materie, MSSM, CMSSM, pMSSM, Higgs-Sektor im MSSM, SUSY-Benchmarks. Dynamische Symmetriebrechung, chirale Symmetriebrechung, Technicolor und Little-Higgs-Modelle. Extra-Dimensionen, Kaluza-Klein-Modell, Bulk und Branes, Gravitation in 4+n Dimensionen, ED-Modelle: ADD, RS, UED.

Measurements of the kinematic distributions of $J/\psi$ mesons produced in $p-$C, $p-$Ti and $p-$W collisions at $\sqrt{s}=41.6 \mathrm{GeV}$ in the Feynman-$x$ region $-0.34 < x_{F} < 0.14$ and for transverse momentum up to $p_T = 5.4 \mathrm{GeV}/c$ are presented. The $x_F$ and $p_T$ dependencies of the nuclear suppression parameter, $\alpha$, are also given. The results are based on $2.4 \cdot 10^{5}$ $J/\psi$ mesons in both the $e^+ e^-$ and $\mu^{+}\mu^{-}$ decay channels. The data have been collected by the HERA-B experiment at the HERA proton ring of the DESY laboratory. The measurement explores the negative region of $x_{F}$ for the first time. The average value of $\alpha$ in the measured $x_{F}$ region is $0.981 \pm 0.015$. The data suggest that the strong nuclear suppression of $J/\psi$ production previously observed at high $x_F$ turns into an enhancement at negative $x_F$.

Inhalte der 7. Online-Vorlesung: Feynman-Regeln der QCD, Farbe als physikalischer Freiheitsgrad, R-Verhaltnis, Pi0-Zerfall, statisches QCD-Potenzial, Quarkonia, Fragmentation, Jets, Entdeckung des Gluons, laufende QED- und QCD-Kopplung, Renormierungsgruppengleichung und Losung fur QCD, Vereinheitlichung der Krafte, Messung von alpha_S.

Inhalte der 9. Online-Vorlesung: W-Boson-Produktion, Korrekturen hoherer Ordnung, Trigger, W/Z+Jets-Produktion, Diboson-Produktion, W-Boson-Masse, Top-Quark-Antiquark-Produktion, Produktion einzelner Top-Quarks, Top-Zerfalle, B-Tagging.

Inhalte der 2. Online-Vorlesung: Photoeffekt, Comptoneffekt, Paarbildung, Strahlungslange, Bethe-Formel, Landau-Verteilung, Delta-Elektronen, Cherenkov-Strahlung, Ubergangsstrahlung, hadronische Wechselwirkungslange.

nhalte der 6. Online-Vorlesung: Leptonische, semileptonische und hadronische Zerfalle; Cabibbo-Theorie; flavorverandernde neutrale Strome und GIM-Mechanismus; CKM-Matrix; Unitaritatsrelationen; Standard- und Wolfenstein-Parametrisierung der CKM-Matrix; Unitaritatsdreieck; Bestimmung der CKM-Matrixelemente; elektroschwache CP-Verletzung; CP-Verletzung bei neutralen Kaonen.

Inhalte der 1. Online-Vorlesung: Naturliche Einheiten, relativistische Kinematik, Pseudorapiditat, Mandelstam-Variablen.

Inhalte der 3. Online-Vorlesung: Grundprinzipien des Teilchenbeschleunigers, aktuelle Beschleuniger, Livingston-Plot, Kathodenstrahlrohre, Cockcroft-Walton- und van-de-Graaff-Beschleuniger, LINAC, Zyklotron und Zyklotronfrequenz, Synchrotron und Synchrotronstrahlung, Luminositat, Vergleich Speicherring und Linearbeschleuniger, neue Beschleunigungskonzepte.

Inhalte der 8. Online-Vorlesung: QCD in Hadron-Hadron-Kollisionen, Drell-Yan-Prozess, Faktorisierung, UV- und IR-Divergenzen, Renormierungs- und Faktorisierungsskala, Jets, Jetalgorithmen, Jetenergieskala, inklusive Jetproduktion am LHC.

Inhalte der 4. Online-Vorlesung: Wellengleichungen in Elektrodynamik und Quantenmechanik, Dirac-Gleichung, diskrete Symmetrien C, P, T, bilineare Kovarianten, Helizitat und Chiralitat, Lagrange-Dichten, Symmetrien und lokale Eichinvarianz und QED, Feynman-Regeln, Yang-Mills-Theorien und QCD.

Inhalte der 5. Online-Vorlesung: Neutrinostrahlen, Entdeckung der Neutralen Strome, SppbarS, Herstellung von Antiprotonen mit stochastischer Kuhlung, Entdeckung der W- und Z-Bosonen, Z-Fabriken LEP und SLC, Experimente an Z-Fabriken, e+e- ? ffbar in QED und an der Z-Resonanz, Bhabha-Streuung, partielle Zerfallsbreiten und Zerfallskanale des Z-Bosons, Strahlungskorrekturen.

The search strategy of the ATLAS experiment for single top quark production during the first two years of data-taking at the LHC is presented. The study focuses on the dominant t-channel production process, assuming an integrated luminosity of 200 pb−1 at a center-of-mass energy of 10TeV. An artificial neural network is employed to control background from t¯t production and W boson production in association with jets. Single-top sensitivities obtained with a sequential cut analysis and a robust likelihood ratio discriminant are compared.

Monte Carlo (MC) simulations are indispensable tools for top quark physics, both at the current Tevatron collider and the upcoming Large Hadron Collider. In this paper we review how the Tevatron experiments CDF and D0 utilize MC simulations for top quark analyses. We describe the standard MC generators used to simulate top quark pair and single top quark production, followed by a discussion of methods to extract systematic uncertainties of top physics results related to the MC generator choice. The paper also shows the special MC requirements for some example top properties measurements at the Tevatron.

The silicon detector system of the CDF-II experiment at the Tevatron proton-antiproton collider at Fermi National Accelerator Laboratory has been operated successfully since the start of Tevatron Run II in 2001. In this article we summarize the experience gained with the silicon detector system, focusing on automation and aging effects of detector components during the years 2006–2008. In addition, we present the most recent updates on studies of single event upsets and radiation damage to the silicon sensors.

Das W‐Boson ist das Feldquant der geladenen schwachen Wechselwirkung. Seine Masse ist etwa 90‐mal höher als die des Protons. Eine neue Präzisionsmessung dieser Masse mit Daten des CDF‐Experiments am Tevatron Collider am Fermilab weist eine signifikante Abweichung vom Standardmodell der Teilchenphysik auf.

Particle therapy is a well established clinical treatment of tumors. More than one hundred particle therapy centers are in operation world wide. The advantage of using hadrons like protons or carbon ions as particles for tumor irradiation is the distinct peak in the depth dependent energy deposition, which can be exploited to accurately deposit dose in the tumor cells. To guarantee this, high accuracy of monitoring and control of the particle beam is of utmost importance. Before the particle beam enters the patient, it traverses a monitoring system which has to give fast feedback to the beam control system on position and dose rate of the beam while minimally interacting with the beam. The multi-wire chambers mostly used as beam position monitor have their limitations when fast response time is required (drift time). Future developments like MRI-guided ion beam therapy pose additional challenges for the beam monitoring system like tolerance of magnetic fields and acoustic noise (vibrations). Solid-state detectors promise to overcome these limitations and the higher resolution they offer can create additional benefits. This article presents the evaluation of an HV-CMOS detector for beam monitoring, provides results from feasibility studies in a therapeutic beam and summarizes the concepts towards the final large-scale assembly and readout system.

The large data samples of thousands of top events collected at the Tevatron experiments CDF and D{O} allow for a variety of measurements to analyze the properties of the top quark. Guided by the question ''Is the top quark observed at the Tevatron really the top quark of the standard model,'' we present Tevatron analyses studying the top production mechanism including resonant t{bar t} production, the V -A structure of the t {yields} Wb decay vertex, the charge of the top quark, and single-top production via flavor-changing neutral currents.

The large data samples of thousands of top events collected at the Tevatron experiments CDF and D0 allow for a variety of measurements to analyze the properties of the top quark. Guided by the question Is the top quark observed at the Tevatron really the top quark of the standard model,'' we present Tevatron analyses studying the top production mechanism including resonant $t\bar{t}$ production, the V-A structure of the $t\to Wb$ decay vertex, the charge of the top quark, and single-top production via flavor-changing neutral currents.

m Mittwoch, den 23. Januar 2019 fand das KIT im Rathaus statt: Das KIT-Zentrum Elementarteilchen- und Astroteilchenphysik spricht uber seine Tatigkeiten und Forschung. Prof. Dr. Ulrich Husemann, Professor fur Experimentelle Elementarteilchenphysik (ETP), spricht in seinem Vortrag uber den Teilchenbeschleuniger Large Hadron Collider (LHC).

KARATE (KArlsruhe high RAte TEst) is a new test system to stress test the readout chain of detector modules for the upgrade of the CMS Outer Tracker for the high-luminosity LHC.Modules consisting of two silicon strip sensors, called 2S modules, are deployed in the outer regions of the Outer Tracker.The readout chain of a 2S module consists of 16 CMS Binary Chips (CBC) each connected to two stacked silicon strip sensors.The CBC contributes data to the first trigger level by identifying particles with large transverse momenta.The output is sparsified on two concentrator chips which in turn are connected to a Gigabit transceiver that prepares the data for output through an optical module.Standard test systems such as test beams or radioactive source measurements need a track reconstruction or do have Gaussian distributed hit profiles and do not reach the occupancy or trigger rates expected in the future Outer Tracker of CMS.KARATE uses a combination of LEDs and photodiodes to inject hit patterns with varying pulse heights, occupancies and trigger rates into the front-end of the CBC, giving full control on 48 channels at 40 MHz.This offers the opportunity to directly compare injection patterns with readout patterns.This contribution introduces the test system and summarizes measurements on a CBC that is read out electrically.

The large data samples of thousands of top events collected at the Tevatron experiments CDF and D0 allow for a variety of measurements to analyze the properties of the top quark. Guided by the question "Is the top quark observed at the Tevatron really the top quark of the standard model,'' we present Tevatron analyses studying the top production mechanism including resonant $t\bar{t}$ production, the V-A structure of the $t\to Wb$ decay vertex, the charge of the top quark, and single-top production via flavor-changing neutral currents.

The silicon detectors of the CDF experiment at the Tevatron collider are operated in a harsh radiation environment. The lifetime of the silicon detectors is limited by radiation damage, and beam-related incidents are an additional risk. This article describes the impact of beam-related incidents on detector operation and the effects of radiation damage on electronics noise and the silicon sensors. From measurements of the depletion voltage as a function of the integrated luminosity, estimates of the silicon detector lifetime are derived.

The HERA-B experiment at DESY has acquired a data set of approximately 300,000 decays J/psi -> l+l- during its 2002/2003 data-taking period. These data are used to analyze the production of heavy quarks in proton-nucleus interactions at a center-of-mass energy of 41.6 GeV. In this article, preliminary results of two measurements are discussed, a measurement of nuclear effects in the production of J/psi mesons and a measurement of the b-bbar production cross section.

Abstract The start of the High-Luminosity LHC (HL-LHC) in 2027 requires upgrades to the Compact Muon Solenoid (CMS) experiment. In the scope of the upgrade program the complete silicon tracking detector will be replaced. The new CMS Tracker will be equipped with silicon pixel detectors in the inner layers closest to the interaction point and silicon strip detectors in the outer layers. The new CMS Outer Tracker will consist of two different kinds of detector modules called PS and 2S modules. Each module will be made of two parallel silicon sensors (a macro-pixel sensor and a strip sensor for the PS modules and two strip sensors for the 2S modules). Combining the hit information of both sensor layers, it is possible to estimate the transverse momentum of particles in the magnetic field of 3.8 T at the full bunch-crossing rate of 40 MHz directly on the module. This information will be used as an input for the first trigger stage of CMS. It is necessary to validate the Outer Tracker module functionality before installing the modules in the CMS experiment. Besides laboratory-based tests several 2S module prototypes have been studied at test beam facilities at CERN, DESY and FNAL. This article concentrates on the beam tests at DESY during which the functionality of the module concept was investigated using the full final readout chain for the first time. Additionally the performance of a 2S module assembled with irradiated sensors was studied. By choosing an irradiation fluence expected for 2S modules at the end of HL-LHC operation, it was possible to investigate the particle detection efficiency and study the trigger capabilities of the module at the beginning and end of the runtime of the CMS experiment.