Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

STAR Heavy Flavor Tracker Detects Signs of Charm at RHIC

20.04.2015

New detector component picks up particles composed of heavy quarks to probe primordial quark-gluon plasma.

The Science


Image courtesy of Brookhaven National Laboratory

The Heavy Flavor Tracker being installed in the heart of the STAR detector at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory.

Thousands of times a second the Relativistic Heavy Ion Collider (RHIC), a particle collider at Brookhaven National Laboratory, creates a quark-gluon plasma—a recreation of the hot quark soup that existed at the dawn of the universe. Particles composed of heavy quarks—which go by whimsical names such as “charm” and “beauty”—can help reveal subtle details about the quark-gluon plasma, and by extension, the early universe and the origins of matter.

The Impact

Nuclear physicists conducting research at RHIC now have the ability to detect these rare, elusive particles using the Heavy Flavor Tracker (HFT), a new component recently installed as part of the STAR experiment. This device will help to precisely measure the plasma’s properties, including its ability to flow like a nearly perfect liquid, and can offer insight into how certain particles lose energy as they traverse the plasma.

Summary

Particles composed of quarks that are heavier than the “up” and “down” quarks that make up ordinary atomic nuclei can help reveal subtle details about a primordial soup made of matter’s building blocks—known as a quark-gluon plasma. This hot quark soup, which existed at the dawn of the universe, is recreated thousands of times a second when ordinary nuclei are smashed together in energetic collisions at the Relativistic Heavy Ion Collider (RHIC), a particle collider at Brookhaven National Laboratory. But the particles containing heavy quarks—which go by whimsical names such as “charm” and “beauty”—are produced only rarely and disappear in an instant. Nuclear physicists conducting research at RHIC now have the ability to detect these rare, elusive particles using the Heavy Flavor Tracker (HFT), a new component recently installed as part of the STAR experiment. This device will help to precisely measure the plasma’s properties, including its ability to flow like a nearly perfect liquid, and can offer insight into how certain particles lose energy as they traverse the plasma.

The STAR Heavy Flavor Tracker (HFT) will provide precise measurements of the production rates of particles containing different combinations of heavy quarks, some of which are heavier than others. Measuring how the heavy particles interact with the quark-gluon plasma will give physicists further insight into the plasma's ability to flow with extremely low viscosity, or resistance—almost like dropping variously sized pebbles into a stream to see how fast it is flowing. These measurements may also help explain the mechanism by which even high-momentum particles appear to lose energy to the plasma. The different abundances and masses of heavy quarks can help differentiate how matter interacts with quarks and provide insight into thermalization—how the matter created in RHIC’s collisions approaches thermal equilibrium. These measurements will lead to a better understanding of properties of the quark-gluon plasma and will stimulate new theoretical studies.

The energy deposited when RHIC collides gold ions at nearly the speed of light creates thousands of new particles, including some rare combinations of different types of heavy quarks. These heavy particles decay in the time it takes them to travel about 100 microns—about the width of a hair. The HFT, now inserted within the core of the STAR experiment, was designed to identify these fleeting heavy particles using a four-layer silicon detector. The first two layers are state-of-the-art pixel detectors (PXL) in which each layer uses silicon pixels with dimensions of 20 by 20 micrometers mounted on very light structures. The PXL detector is the first at a collider to use a new detector concept called Monolithic Active Pixel Sensors (MAPS). The MAPS sensors are thinned to 50 micrometers and have been placed very close to the beam line in which the particle collisions take place so they can track the elusive heavy particles immediately after they decay. The entire PXL detector can be retracted and if necessary replaced with a spare within a 24-hour period. Both the high resolution and the low mass of the detector represent a breakthrough in pixel technology. Two additional silicon-detector systems are used to increase the efficiency of the HFT. A single cylindrical layer of silicon pad detectors (IST) surrounds the PXL. The outermost detection layer consists of double-sided Silicon Strip Detectors (SSD).

The PXL detector was designed and built at Lawrence Berkeley National Laboratory (LBNL) using novel MAPS sensors that were developed at Institut Pluridisciplinaire Hubert CURIEN (IPHC, Strasbourg, France). The IST was designed and built at MIT, the University of Illinois at Chicago, and Indiana University; while the SSD readout electronics were built at LBNL and designed by a collaboration between LBNL and Subatech (Nantes, France). Overall detector integration was done by BNL and LBNL; and project management was provided by BNL with assistance from LBNL.

Installed at the STAR detector in time for the 2014 RHIC run, the HFT detector has so far recorded 1.2 billion gold-gold collision events, meeting all expectations in its performance to date. The STAR collaboration has begun analyzing this abundance of new data and looks forward to incorporating it into a deeper understanding of the quark-gluon plasma created at RHIC.

Funding

The Heavy Flavor Tracker is an Office of Nuclear Physics supported MIE project which was initiated in 2010. The following STAR institutions are collaborators in this work: BNL, Czech Technical University and NPI Prague, UCLA, Indiana University Cyclotron Facility, IPHC Strasbourg, MIT, LBNL, Purdue University, SUBATECH Nantes, UIC and UT Austin.

Publications

L. Greiner et al., "A MAPS based vertex detector for the STAR experiment at RHIC." Nucl. Instr. and Meth. A 650 (1), 68-72 (2010). [DOI: 10.1016/j.nima.2010.12.006]

C. Hu-Guo et al., "First reticule size MAPS with digital output and integrated zero suppression for the EUDET-JRA1 beam telescope." Nucl. Instrum. Meth. A 623 (1), 480-482 (2010). [DOI: 10.1016/j.nima.2010.03.043]

Contact Information
Kristin Manke
kristin.manke@science.doe.gov

Kristin Manke | newswise
Further information:
http://www.science.doe.gov

More articles from Physics and Astronomy:

nachricht Tune your radio: galaxies sing while forming stars
21.02.2017 | Max-Planck-Institut für Radioastronomie

nachricht Breakthrough with a chain of gold atoms
17.02.2017 | Universität Konstanz

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Impacts of mass coral die-off on Indian Ocean reefs revealed

21.02.2017 | Earth Sciences

Novel breast tomosynthesis technique reduces screening recall rate

21.02.2017 | Medical Engineering

Use your Voice – and Smart Homes will “LISTEN”

21.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>