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Jens Soeren Lange

Publications and source records attributed to Jens Soeren Lange.

9 recordsLinked to original sources
arXiv2019

Search for Highly Ionizing Particles with the Pixel Detector at Belle II

The Belle II experiment, located at the SuperKEKB collider at the high-energy research facility KEK in Tsukuba, Japan, started operation in 2018. Compared to the predecessor experiment Belle, Belle II plans to increase the peak luminosity by a factor of about 40, by employing nano-beam technology in the interaction region. In particular the new, innermost sub-detector of Belle II - the Pixel Vertex Detector (PXD) - is in close proximity to the interaction point. This allows for the detection of particles, which do not leave a signal in the outer sub-detectors. Among these, Highly Ionizing Particles (HIPs) encounter a characteristically high energy loss, limiting their penetration depth into the detector. Anti-deuterons and magnetic monopoles as possible HIPs are considered. Without a signal in the outer sub-detectors, no track trigger is issued, resulting in possible information loss. The possibility of identifying HIPs solely with information provided by the PXD is presented, by using neural network algorithms operating in a multidimensional parameter space of PXD cluster data.

physics.ins-det↗
arXiv2015

New Spectroscopy with PANDA at FAIR: X, Y, Z and the F-wave Charmonium States

Charm and charmonium physics have gained renewed interest in the past decade. Recent spectroscopic observations strongly motivate these studies. Among the several possible reactions, measurements in proton-antiproton annihilation play an important role, complementary to the studies performed at B-factories. The fixed target PANDA experiment at FAIR (Darmstadt, Germany) will investigate fundamental questions of hadron and nuclear physics in the interactions of antiprotons with nucleons and nuclei. With reaction rates as large as 2*10^7 interactions/s, and a mass resolution 20 times better as compared with the most recent B-factories, PANDA is in a privileged position to successfully perform the measurement of the width of narrow states, such as the X(3872). PANDA will investigate also high spin particles, whose observation was forbidden at B-factories, i.e. F-wave charmonium states. In this report extrapolations on cross sections and rates with PANDA are given.

hep-ex↗
arXiv2012

QCD studies and discoveries with e+e- colliders and future perspectives

Observations of new charmonium(-like) and bottomonium(-like) states (sometimes refered to as "XYZ" states) at e+e- colliders have changed our picture of quarkonia systems as QCD bound states. Potential models with a linear confinement ansatz, which were able to predict many conventional states with an accuracy of ~1 MeV, absolutely fail in describing many of the new states. Symmetries play an important role e.g. in the determination of the quantum numbers (such as charge conjugation in the radiative decays) or in trying to explain surprising properties such as isospin violation. It will also be discussed, how future experiments (Panda, Belle II) can help to understand the nature of these states.

hep-ex↗
arXiv2009

Plans for PANDA Online Computing

The PANDA experiment will not use any hardware trigger, i.e. all raw data are streaming in the data acquisition with a bandwidth of ~280 GB/s. The PANDA Online System is designed to perform data reduction by a factor of ~800 by reconstruction algorithms programmed in VHDL (Very High Speed Integrated Circuit Hardware Description Language) on FPGAs (Field Programmable Gate Arrays).

physics.ins-det↗
arXiv2008

Charm and Tau Decays: Review of BaBar and Belle Results

A review of recent results concerning decays of charmed mesons, charmed baryons and $τ$ leptons for the Belle and BaBar Experiments is given. The review was presented at the 43$^{rd}$ Rencontres de Moriond (QCD and High Energy Interactions), LaThuile, March 8-15, 2008.

hep-ex↗
arXiv2004

A Comparison Between An Ultra-Relativistic Au+Au Collision and the Primordial Universe

Ultra-relativistic nucleus-nucleus collisions create a state of matter of high temperature and small baryo-chemical potential, which is similar to the thermodynamical conditions in the primordial universe. Recent analyses of Au+Au collisions at RHIC revealed the temperature, size and density of the system. Thus, a comparison to the primordial universe can be attempted. In particular, two observables shall be investigated, namely (1) the temperature at baryon freeze-out (about t=10 fm/c in the $Au$ + $Au$ collision) and (2) the matter density at the partonic stage (t>1 fm/c).

hep-ph↗
arXiv2004

Anti-d and Anti-He Production in Au+Au Collisions at RHIC

Ultra-relativistic Au+Au collisions at RHIC ($\sqrt{s}$=130, 200 GeV) are used to study production of rare anti-nuclei. These clusters of anti-nucleons are formed by coalescence, i.e. overlapping wave functions of anti-nucleons. The coalescence coefficients $B_2$ for Anti-$d$ and $B_3$ for Anti-$^3He$ are determined, and used to derive the fireball radius.

nucl-ex↗
arXiv2003

B physics at STAR

Review of search for heavy flavor (c,b quarks) production in leptonic decay channels in Au+Au collisions at \sqrt{s_NN}=200 GeV at the STAR Experiment at RHIC.

nucl-ex↗