dark matter – Polkinghorne http://polkinghorne.org/ Sun, 13 Mar 2022 14:21:09 +0000 en-US hourly 1 https://wordpress.org/?v=5.9.3 https://polkinghorne.org/wp-content/uploads/2022/01/icon-2022-01-25T202759.511-150x150.png dark matter – Polkinghorne http://polkinghorne.org/ 32 32 Brunel backed to play his part in the future of particle physics https://polkinghorne.org/brunel-backed-to-play-his-part-in-the-future-of-particle-physics/ Fri, 11 Mar 2022 12:05:58 +0000 https://polkinghorne.org/brunel-backed-to-play-his-part-in-the-future-of-particle-physics/ Brunel University London has been supported by funding from the Science and Technology Facilities Council (STFC) to play its part in the future of particle physics research. The university is one of 18 UK institutions to receive a share of a new £60million fund, which the STFC hopes will keep the UK at the forefront […]]]>

Brunel University London has been supported by funding from the Science and Technology Facilities Council (STFC) to play its part in the future of particle physics research.

The university is one of 18 UK institutions to receive a share of a new £60million fund, which the STFC hopes will keep the UK at the forefront of physics, answering some of the questions most fundamental scientists while supporting the next generation of particle physicists. .

The funding will allow Brunel to expand his work at the famous Large Hadron Collider at CERN, where researchers and university students have long worked on some of the biggest experiments in the world.

This work includes maintaining and operating the enormous Compact Muon Solenoid (CMS) Silicon Tracker, a detector that allows scientists to track the momentum of charged particles.

“The Silicon Tracker is at the heart of CERN’s CMS experiment and is one of the largest silicon devices ever built – it measures around 200 square meters. About the size of a tennis court,” said Professor Akram Khan, professor of experimental particle physics at Brunel.

“Its main function in life is to measure particle tracks. When you get a high-energy collision, you get secondary particles from those collisions – and we help determine the trajectory the particles are taking and where they’re coming from.

Using the Silicon Tracker, CERN scientists can track the position of a particle to about 10 microns, or about the width of a human hair.

The new STFC funding will also allow Brunel students and early career researchers to continue working with CERN, where they have already had the opportunity to work on some of the organization’s largest projects.

“Our students have the chance to work on really advanced technologies, such as the electronics of the trigger system. These are bespoke electronic devices that don’t exist anywhere else,” Prof Khan said.

“They may also be involved in testing algorithms, and sometimes developing and tweaking algorithms. But I think the important thing is to get the algorithms and hardware working in real time – they can really get your hands dirty!”

The STFC is one of the main research funding bodies in the UK, supporting particle physicists working in a variety of fields including dark matter, neutrinos and proton decay.

Announcing the funding, Professor Grahame Blair, Executive Director of Programs at STFC, said: “STFC continues to support the experimental particle physics community in the UK by answering fundamental questions about our universe.

“Grants are essential to support technicians, engineers and academics in their skills and expertise in the field, while encouraging career development in basic research with universities and international collaborators.

“This investment supports the UK physics community and enables the UK to remain a leader in the field of experimental particle physics.

Reported by:

Press office, media relations

+44 (0)1895 268965
press-office@brunel.ac.uk

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Lancaster receives £2.9m for particle physics research https://polkinghorne.org/lancaster-receives-2-9m-for-particle-physics-research/ Thu, 10 Mar 2022 13:14:00 +0000 https://polkinghorne.org/lancaster-receives-2-9m-for-particle-physics-research/ Lancaster University has received £2.9 million from the Science and Technology Facilities Council (STFC) as part of its ongoing support for the particle physics research community in the UK. This funding helps keep the UK at the forefront of answering some of the most important and complex scientific questions and supports the next generation of […]]]>

Lancaster University has received £2.9 million from the Science and Technology Facilities Council (STFC) as part of its ongoing support for the particle physics research community in the UK.

This funding helps keep the UK at the forefront of answering some of the most important and complex scientific questions and supports the next generation of UK particle physicists.

The funding will allow the Experimental Particle Physics Group at Lancaster to continue its world-class research to study phenomena in particle physics with a focus on determining the dominance of matter over antimatter in the Universe, precise measurements of the best current theoretical description of particle physics. (the “standard model”) as well as theories that go beyond this theory.

The program uses facilities around the world including CERN (Switzerland/France), Fermilab (USA), JPARC (Japan) and SNOLab (Canada) and the group participates in and leads many activities at CERN (ATLAS and NA62 ) and neutrino ( DUNE, T2K, HK, MicroBooNE, SBND).

Professor Roger Jones of Lancaster University said: “At a time of very tight budgets, we are pleased to have increased our grant support and will be able to continue a broad and exciting program addressing the fundamental questions of particle physics.

Particle physics studies the world at the smallest possible distance scales and at the highest attainable energies, seeking answers to fundamental questions about the structure of matter and the composition of the Universe.

Ten years after British researchers contributed to the Nobel Prize-winning detection of the Higgs boson, some of the questions the community is struggling to answer include:

  • What is the Universe made of and why?
  • What is the underlying nature of neutrinos?
  • Why is there an imbalance between matter and antimatter in the Universe?
  • How to detect dark matter?
  • Are there any new particles or particle interactions we can find?

Professor Grahame Blair, Executive Director of Programs at STFC, said:

“The STFC continues to support the experimental particle physics community in the UK by answering fundamental questions about our Universe.

“Grants are essential to support technicians, engineers and academics in their skills and expertise in the field, while encouraging career development in basic research with universities and international collaborators.

“This investment supports the UK physics community and enables the UK to continue to lead the field of experimental particle physics.”

/Public release. This material from the original organization/authors may be ad hoc in nature, edited for clarity, style and length. The views and opinions expressed are those of the author or authors. See in full here.

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University of Sheffield researchers awarded over £2.6m to support particle physics research | News https://polkinghorne.org/university-of-sheffield-researchers-awarded-over-2-6m-to-support-particle-physics-research-news/ Wed, 09 Mar 2022 13:13:51 +0000 https://polkinghorne.org/university-of-sheffield-researchers-awarded-over-2-6m-to-support-particle-physics-research-news/ Physicists at the University of Sheffield have been awarded more than £2.6 million to answer fundamental questions about the composition of the universe. Physicists from the University of Sheffield’s Department of Physics and Astronomy have been awarded £2.68 million for pioneering research aimed at answering some of the biggest and most complex questions in science […]]]>

Physicists at the University of Sheffield have been awarded more than £2.6 million to answer fundamental questions about the composition of the universe.

  • Physicists from the University of Sheffield’s Department of Physics and Astronomy have been awarded £2.68 million for pioneering research aimed at answering some of the biggest and most complex questions in science
  • The funding is part of a wider £60m investment from the Science and Technology Facilities Council (STFC) to keep the UK at the forefront of global particle physics research and to support the next generation of British particle physicists.
  • The grant will support high-level work in the particle physics group that combines experimental accelerator particle physics, neutrino physics, and particle astrophysics with a strong focus on impact

Physicists at the University of Sheffield have been awarded more than £2.6 million to answer fundamental questions about the composition of the universe.

The £2.68million grant, from the Science and Technology Facilities Council (STFC), is part of a wider £60million investment to keep the UK at the forefront of global research by particle physics and to support the next generation of particle physicists.

Particle physics is the study of the world both at the smallest possible scales and at the highest attainable energies, seeking answers to fundamental questions about the structure of matter and the composition of the Universe.

Professor Lee Thompson, from the University of Sheffield’s Department of Physics and Astronomy, will lead the institute’s particle physics programme, which aims to answer fundamental questions such as:

  • “What is the Universe made of and why?”
  • “Why is the Universe made of matter and not anti-matter? »

Among the activities of the particle physics group is the search for dark matter – a hypothetical form of matter thought to make up about 85% (five-sixths) of the matter in the universe. Although it was first discovered in 1933, it has still never been observed directly.

Elsewhere, the Sheffield team is taking part in the large multi-purpose ATLAS experiment at CERN’s Large Hadron Collider to search for new particles. Other team members are collaborating on next-generation neutrino experiments in Japan and the United States to observe subtle differences between particles and antiparticles.

Professor Lee Thompson, Principal Investigator for Sheffield from the university’s Department of Physics and Astronomy, said: “This funding will have a significant impact on our efforts to answer some of the most important and fundamental questions about the Universe.”

“We are working in collaboration with colleagues around the world on a wide range of pioneering experiments to help us better understand the nature of matter and discover hitherto elusive dark matter. STFC funding will allow us to continue our groundbreaking work here in Sheffield and get one step closer to answering some of the most important and complex questions in science.

The STFC investment will fund teams from a total of 18 UK universities to conduct cutting-edge research in particle physics over the next three years.

Professor Grahame Blair, Executive Director of Programs at STFC, said: “STFC continues to support the experimental particle physics community in the UK by answering fundamental questions about our universe.

“Grants are essential to support technicians, engineers and academics in their skills and expertise in the field, while encouraging career development in basic research with universities and international collaborators.

“This investment supports the UK physics community and enables the UK to continue to lead the field of experimental particle physics.”

The STFC funds UK particle physicists working on a wide range of experiments around the world. Research teams are working to solve groundbreaking challenges in particle physics, including the race to detect dark matter, the study of neutrino oscillations, and the search for proton decay – all key questions in fundamental physics to which we still have no answers.


Contact

For more information, please contact:

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Liverpool at the forefront of global particle physics research with £6.59m investment – ​​News https://polkinghorne.org/liverpool-at-the-forefront-of-global-particle-physics-research-with-6-59m-investment-%e2%80%8b%e2%80%8bnews/ Wed, 09 Mar 2022 08:13:00 +0000 https://polkinghorne.org/liverpool-at-the-forefront-of-global-particle-physics-research-with-6-59m-investment-%e2%80%8b%e2%80%8bnews/ Physicists at the University of Liverpool are receiving £6.59m from the Science and Technology Facilities Council (STFC) as part of a £60m investment to continue supporting the physics research community particles in the UK. The funding helps keep Liverpool and the UK at the forefront of answering some of the most important and complex scientific […]]]>

Physicists at the University of Liverpool are receiving £6.59m from the Science and Technology Facilities Council (STFC) as part of a £60m investment to continue supporting the physics research community particles in the UK.

The funding helps keep Liverpool and the UK at the forefront of answering some of the most important and complex scientific questions and supports the next generation of UK particle physicists.

Alongside Oxford and Imperial College, the University of Liverpool is one of the largest of 18 STFC-funded university projects to conduct cutting-edge research in particle physics over the next three years.

Liverpool physicists will focus on finding answers to some of the most pressing questions in particle physics, such as understanding the nature of dark matter or why we live in a universe that seems almost entirely devoid of dark particles. ‘antimatter.

To do this, they will continue work on several experiments in progress and under development. These include experiments at the Large Hardon Collider at CERN and neutrino experiments, precision muon experiments and dark matter research at laboratories in the United States, Europe and Japan. .

Recent hints from different experiments have offered tantalizing clues that new breakthroughs in particle physics could come from experiments that are underway or from experiments already in the works.

The University of Liverpool Principal Investigator for this award is Professor Joost Vossebeld who said: “This funding is fantastic news for physicists at Liverpool and a testament to both the cutting-edge research we are undertaking and the leading role Liverpool is playing in developing the next generation of experiments in particle physics. Success belongs to everyone in the Liverpool group, be they academics, students, engineers, technicians or computer scientists. We are all very excited to see what the next three years have in store for us.

Professor Grahame Blair, Executive Director of Programs at the STFC, said: “The STFC continues to support the experimental particle physics community in the UK by answering fundamental questions about our Universe.

“Grants are essential to support technicians, engineers and academics in their skills and expertise in the field, while encouraging career development in basic research with universities and international collaborators.

“This investment supports the UK physics community and enables the UK to continue to lead the field of experimental particle physics.”

The STFC funds UK particle physicists working on a wide range of experiments around the world. UK-funded research teams are working to solve groundbreaking challenges in particle physics, including the race to detect dark matter, the study of neutrino oscillations and the search for proton decay – all key questions in fundamental physics that we still have not answered.

More information on STFC’s $60 million investment in global physics research can be found here.

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Some thoughts on the Standard Model of Particle Physics – Kashmir Reader https://polkinghorne.org/some-thoughts-on-the-standard-model-of-particle-physics-kashmir-reader/ Sat, 05 Feb 2022 19:58:00 +0000 https://polkinghorne.org/some-thoughts-on-the-standard-model-of-particle-physics-kashmir-reader/ It doesn’t answer the most fundamental mystery: what constitutes the dark energy and dark matter that make up the majority of our universe? The Standard Model became the fundamental model of elementary particle physics in the second half of the 20th century. It is considered today as the best description of the constituent elements of […]]]>

It doesn’t answer the most fundamental mystery: what constitutes the dark energy and dark matter that make up the majority of our universe?

The Standard Model became the fundamental model of elementary particle physics in the second half of the 20th century. It is considered today as the best description of the constituent elements of the universe. It explains how quarks (which form protons and neutrons) and leptons (electrons, etc.) make up all known matter. It is also an explanation of how quarks and leptons are influenced by the exchange of intermediate force carriers. It describes three of the four fundamental interactions that sum up the structure of matter up to the measurement of 10 high at -18 meter. It is in short a quantum theory of three basic theories of electromagnetic interaction, strong interaction and weak interaction. The development of the Standard Model has been led by a large number of experimental and theoretical physicists alike. The structure or mathematical framework of the Standard Model is provided by quantum field theory
According to the standard model, all matter is made up of three types of elementary particles: leptons, quarks and their mediators. There are six leptons divided into three generations. There are also six anti-leptons, so the total number of leptons is 12. Similarly, the number of quarks is six, each of which comes in three colors (this color bears no resemblance to the concept of color in our daily life), which represents 36 quarks in total, including the antiquarks. Quarks like leptons have three generations. Finally, for each interaction, we have a mediator. The carrier of the electromagnetic interaction is a massless photon while the carriers of the weak interaction are called intermediate vector bosons, which are two charged Ws and a neutral heavy Z. Finally, for the strong interaction exchange, we have 8 gluons.
The missing link of the Standard Model, the Higgs boson theoretically predicted by Peter Higgs in the early 1960s, which explains the mass of elementary particles via the Higgs mechanism, involving chiral symmetry breaking, was discovered in 2012 at Large Hadron Collider in Geneva, Switzerland. The marvelous achievement of the Standard Model can be measured by the simple fact that it has led to more than 50 Nobel Prizes in Physics so far.
Loopholes:
Even though the Standard Model is currently the best description we have of the subatomic world, but despite its robust predictions, there is a consensus among physicists that the Standard Model is neither complete nor the final theory. “There is a certain degree of ugliness in the standard model,” says Steve Weinberg, one of its main architects. First, the standard model is completely silent about dark energy and dark matter. This does not answer the question of what constitutes the dark energy and dark matter that make up the majority of matter in our universe. Second, it fails to explain neutrino oscillations and, more importantly, it fails to incorporate one of the most fundamental interactions, gravity, which explains the large-scale structure of the universe. At a more fundamental level, he fails to explain why there are precisely three generations of quarks and leptons. Likewise, the difference in masses of the elementary particles that they acquire due to their interaction with the Higgs field via the Higgs boson remains a mystery.
Possible output:
In order to accommodate many of the shortcomings of the Standard Model listed above, physicists over time have come up with different theories and approaches. All of these theories and approaches fall under the category “Physics Beyond the Standard Model”. Theories that lie beyond the Standard Model include the various extensions of supersymmetry and entirely new explanations and theories such as string theory, looping quantum gravity, and extra dimensions. But the theory that has gained most prominence among them is string theory. String theory has captured the imagination of a generation of particle physicists over the past 40 years. String theory not only promises the reconciliation of quantum mechanics with Einstein’s general relativity and eliminates the infinities that plague quantum field theory, it also provides a unified theory of everything from which all elementary particle physics , including gravity, would emerge as an inevitable consequence. But the bottleneck of particle physics, as string theorist and Nobel laureate David Gross puts it, is experimental, not theoretical, so in the absence of experimental evidence to back up his predictions, the future of string theory seems grim, or at least you have to cross your fingers. If string theory lives up to expectations, which seems unlikely, it will be the ultimate triumph of the human spirit.

—The author is a physics student
[email protected]





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Beate Heinemann becomes the new director in charge of particle physics at DESY https://polkinghorne.org/beate-heinemann-becomes-the-new-director-in-charge-of-particle-physics-at-desy/ Tue, 07 Dec 2021 08:00:00 +0000 https://polkinghorne.org/beate-heinemann-becomes-the-new-director-in-charge-of-particle-physics-at-desy/ A professor of physics completes the board of directors of the Research Center First woman on the board of DESY: Beate Heinemann. Image: DESY / Angela Pfeiffer Beate Heinemann, DESY Principal Investigator and Professor of Physics at the University of Fribourg, will take over as Director of DESY’s High Energy Physics Division on February 1. […]]]>

A professor of physics completes the board of directors of the Research Center

First woman on the board of DESY: Beate Heinemann. Image: DESY / Angela Pfeiffer

Beate Heinemann, DESY Principal Investigator and Professor of Physics at the University of Fribourg, will take over as Director of DESY’s High Energy Physics Division on February 1. This was unanimously decided by DESY’s supervisory body, the Foundation Council, at its meeting on 7 December. Heinemann is the first female director in the history of DESY.

“Beate Heinemann is a real asset to the research centre,” says Dr. Volkmar Dietz of the Federal Ministry of Education and Research, Chairman of the Foundation Board. “With her international experience, vast knowledge, reputation and forward-looking ideas, she will certainly lead the field of particle physics research into the next exciting era. As the first female CEO, she will mark also the DESY story!”

Beate Heinemann is a true Hamburger, having grown up very close to DESY in Hamburg. She cut her teeth in particle physics experiments and at universities and research centers around the world. After completing her PhD at the University of Hamburg on an experiment at DESY’s HERA accelerator, she joined the CDF experiment at Fermilab near Chicago as a scientist at the University of Liverpool before becoming a professor at the ‘University of California at Berkeley working on the ATLAS experiment, a giant particle detector at CERN in Geneva. From 2013 to 2017, she was deputy spokesperson for the ATLAS experiment. She then returned to Germany to continue her research with ATLAS as a senior scientist at DESY and a professor at the University of Freiburg.

“I am very pleased that Beate Heinemann will join the management of DESY in the future”, says Helmut Dosch, Director of DESY. “His excellent expertise in particle physics and his experience in managing large international teams are perfectly suited to the many facets of fundamental research at DESY and the Helmholtz Association. We are proud to welcome him to the team and have looking forward to shaping the future with her.”

Heinemann succeeds Joachim Mnich, who joined European research center CERN as research director in early 2021, and Ties Behnke, who led the research division as interim director. At DESY, the particle physics division includes not only the particle physicists and technicians involved in the international experiments, but also theorists, the DESY computer department, the library and many service groups such as electronics development.

“DESY is a world-class laboratory and I am thrilled to be part of shaping its present and its future,” says Heinemann. “Many topics and projects are close to my heart – from fundamental research and developments in future technologies to sustainability and diversity. The next decade offers many exciting challenges, both scientifically and socially, and I look forward to the decisive contributions DESY will meet these challenges.”

We spoke to the new director and asked her about her plans and ideas.

What are your plans for your new research center?

As Director, you are not only responsible for your own division, but for DESY as a whole. DESY as a whole is close to my heart. First of all, I think it is very important that we maintain and further expand our pioneering role as a center for fundamental research for the study of matter.

We know that many of the major breakthrough developments and changes stem from basic research. This is why I think it should continue to be the basis of research at DESY – but we also have actions and a research mandate in application-oriented fields, for example climate, digitalization or health . DESY can contribute with all its research areas, for example through new accelerator technologies, new methods for developing detectors or new facilities for photon science. And we must also prioritize sustainability on campus.

Another topic close to my heart, both personally and through my new office, is diversity. DESY must remain a cosmopolitan and diverse laboratory, and there is still room for improvement in many areas, for example the number of women in leadership positions.

And what about your own research division?

Of course, I also have ideas for particle physics, which is based on several very strong pillars at DESY: we participate in international experiments, have our own very interesting experiments on campus, a strong theory group and we are pioneers of digital transformation with our IT sector. . Thanks to our cutting-edge research, we are also very attractive to young scientists who come to us from countries all over the world to do their PhD, postdoctoral research or take up a staff position. We must continue to evolve to stay at the international forefront and review our strategy for the next decade.

In our detector assembly facility here on campus, for example, we are building several core components for the upgrade of experiments as part of the LHC accelerator expansion. DESY has taken on a huge responsibility – it is important that we deliver!

But we can also be proud of the exciting experiments we carry out here at DESY in the framework of international collaboration. The ALPS II experiment will begin next year. ALPS searches for dark matter using small, elusive particles called axions, which also play a role in several other experiments that are on DESY’s wish and planning list. If they all came, which I will of course defend, DESY would be world-leading in the very dynamic field of axion research. The excellent infrastructure we have at DESY as a national research laboratory for particle physics plays a major role here.

We can also be very proud of our theory. It rightly enjoys an excellent reputation around the world, based in particular on the fact that our experts cover more than 60 orders of magnitude in physics – from string theory to cosmology. With the future Wolfgang Pauli Center, it will be even larger and more multidisciplinary.

In the next few years, the course will be set for the successor project to the LHC, namely the next big particle accelerator, the technology and location of which have not yet been chosen. It is very important to me that DESY also actively participates in the preparation of this project in order to maintain and expand its pioneering role.

These are just a few of my ideas and we should always be open to new ones. We have a lot of smart, creative people here, and you never know what spectacular proposition they’ll come up with next.

DESY aside – what are the things that are most important to you?

Above all, durability is very important to me. Our generation bears the responsibility now; we must act now and think climate in everything, both in research and in the development of the DESY campus and Science City Bahrenfeld.

Fundamental research is also close to my heart because not only is it extremely interesting, but it can also stimulate innovation. Take for example the mRNA vaccine, which is based on 20 years of basic research, or the accelerators, which were developed 100 years ago in particle physics and are now used worldwide to treat tumors.

But above all, I am still determined to find out how nature works and what laws of nature underlie it. In my opinion, we are now in the most exciting period in particle physics since the structure of the atom was first discovered and then understood in the early 20th century. In about forty years, physics has been completely revolutionized. At this moment, we are again entering a new energy scale, the electroweak force scale, which is closely related to the Higgs particle and gives us many questions. Studying this scale in detail now is extremely exciting and can also lead to groundbreaking discoveries that no one can even dream of today.

You were born in Hamburg and also studied here. What’s it like to become the first female director at DESY?

First of all, it is a great honor for me to be the first female director at DESY, having taken my first career steps at DESY during my university studies. In general, it is very, very important to me that women have the same opportunities and find the same conditions as men in all areas. In a modern society, we must make the most of everyone’s potential, regardless of gender, religion or social or ethnic origin.

And I’ve always stayed connected to Hamburg: I’m a big HSV fan! As the eldest of three siblings, my dad took me to the stadium from an early age, and to this day I still watch every game with him (although usually on the couch rather than in the stadium) .

DESY is one of the world’s leading particle accelerator centers and studies the structure and function of matter – from the interaction of tiny elementary particles and the behavior of new nanomaterials and vital biomolecules to the great mysteries of the universe. . The particle accelerators and detectors that DESY develops and builds at its sites in Hamburg and Zeuthen are unique research tools. They generate the most intense X-radiation in the world, accelerating particles to record energies and opening new windows on the universe. DESY is a member of the Helmholtz Association, Germany’s largest scientific association, and receives its funding from the German Federal Ministry of Education and Research (BMBF) (90%) and the German federal states of Hamburg and Brandenburg (10%).

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Particle physics experiment may have directly observed dark energy https://polkinghorne.org/particle-physics-experiment-may-have-directly-observed-dark-energy/ Fri, 29 Oct 2021 16:09:08 +0000 https://polkinghorne.org/particle-physics-experiment-may-have-directly-observed-dark-energy/ About 25 years ago, astrophysicists noticed something very interesting about the Universe. The fact that it was expanding had been known since the 1920s, thanks to the observation of Edwin Hubble. But thanks to the observations that astronomers made with the space observatory that bore his name (the The Hubble Space Telescope), they began to […]]]>

About 25 years ago, astrophysicists noticed something very interesting about the Universe. The fact that it was expanding had been known since the 1920s, thanks to the observation of Edwin Hubble. But thanks to the observations that astronomers made with the space observatory that bore his name (the The Hubble Space Telescope), they began to notice how the rate of cosmic expansion was accelerating!

This led to the theory that the Universe is filled with an invisible and mysterious force, known as dark energy (DE). Decades after its proposal, scientists are still trying to pin down this elusive force that accounts for about 70% of the Universe’s energy budget. According to a recent study by an international team of researchers, the XENON1T experiment may have already detected this elusive force, opening new possibilities for future ED research.

The research was led by Dr Sunny Vagnozzi, a researcher at the Kavli Institute of Cosmology (KICC) at the University of Cambridge, and Dr Luca Visinelli, a Fellowship for Innovation (FELLINI) researcher (who is maintained with the support of the Marie Bourse Sklodowska-Curie) at the National Institute of Nuclear Physics (INFN) in Frascati, Italy. They were joined by researchers from the Institute for Theoretical Physics (IPhT), the University of Cambridge and the University of Hawaii.

Both DM and DE are part of the Lambda Cold Dark Matter (LCDM) model of cosmology, which posits that the Universe is filled with cold, slow-moving (DM) particles that interact with normal matter via the force of gravity alone. Lambda represents DE, which is accelerating the expansion of the Universe. Since they are only discerned by observing their effect on the large-scale structure of the Universe, conventional thought holds that none of the forces interact with normal matter via electromagnetism or the weak or strong nuclear force. .

However, some DM theories posit that there is some level of interaction with visible matter, which researchers are actively testing. However, instead of more test results, astrophysicists and cosmologists still don’t know how DE fits into the physical laws that govern the Universe. Candidates so far include a modification of Einstein’s general relativity (GR), the presence of a new field, or a cosmological constant (CC). As Dr. Visinelli told Universe Today via email:

“For this reason, dark energy is perhaps even more mysterious than dark matter. We are seeing the effects of dark energy across a number of observations, starting with the seminal work on 1A supernovae in as standard candles. Assuming that dark energy is indeed a field, the quanta associated with it would be extremely light and carry very little energy. This is the reason why very little work has been done on this type of searches.

Their work is based on new research that goes beyond the standard LCDM model of cosmology to consider that DE interacts with light by affecting its properties (i.e. polarization, color, direction ). However, these interactions could be subject to screening mechanisms that prevent local experiments from detecting them. In this model, it is predicted that dark energy quanta can be produced in the Sun.

XENON1T detector

The XENON1T detector, shown below. Credit: XENOX Collaboration

As Dr. Vagnozzi explained, the possible connection between screening and dark energy first came to him when he was taking a shower one day:

“I remember it was June 20 and I was taking a shower and thinking about solar axions (without) explaining XENON, and I realized the obvious solution was screening, because that would stop production in the denser stars. Screening is usually associated with patterns of dark energy and/or altered gravity, and there has been the “click”.

“I immediately Whatsapped Luca and we immediately started working on it (and reached out to our other co-authors who are experts in filtered dark energy/modified gravity patterns).”

For the purposes of their study, the team led by Dr. Vagnozzi and Dr. Visinelli reviewed data published by the XENON Collaboration, a DM research team made up of 135 researchers from 22 institutions around the world. At the heart of their experiment is a 3,500 kg (7,715 lb) detector of ultra-radio-pure liquid xenon housed in a 10 m (32.8 ft) tank of water. Located at the INFN Laboratori Nazionali del Gran Sasso, XENON is also the most sensitive dark matter (DM) experiment ever performed.

In 2020, the Collaboration published the results of its experimental campaign (2016 to 2018), which showed an unexpected rate of electronic recoil events. According to the collaboration, this did not constitute a detection of DM but could be explained by a tiny residual quantity of tritium in the experiment, the existence of a new particle (such as the solar axion), or an unexplained property of the neutrinos.

Upper PMT Matrix

The upper PMT network with all the electrical cables. Credit: XENON Dark Matter Project

For the purposes of their study, however, the team led by Vagnozzi and Visinelli speculated that this may have been the first direct detection of DE. Said Vagnozzi:

“In our model, dark energy has special properties: its mass term is related to the density of the environment, so denser materials would shield the effects of dark energy, while denser environments light such as intergalactic space would allow for long range dark energy.

“In this model called the ‘chameleon’, quanta of dark energy are produced in the region of the Sun in which the electromagnetic field is strongest, the tachocline, which is the region in which the transport of energy to the interior of the Sun changes from radiative to convection.The high energy density of the electromagnetic radiation in the region allows a strong coupling with the chameleon field and its production.

If true, this would mean that experiments around the world currently focused on dark matter research could also be devoted to the hunt for dark energy. To that end, Dr. Vagnozzi and Dr. Visinelli hope that this study will spark interest in particle models of ED and that the search for these elusive particles can be conducted in parallel with ongoing DM research. At the very least, these experiments will test theories about ED that go beyond the LCDM model, helping scientists narrow down the list of candidates. Says Dr. Visinelli:

“Many other experiments designed for Dark Matter may also contain information about these chameleons, and we hope that the design of future setups for this research will be considered. An independent test using cosmological data crossed with the predictions of the chameleon model would also be necessary. As for us, we plan to refine our paper’s calculations using a solar model, study chameleon production in massive stars, and get in touch with experimentalists for updates.

Illustris dark matter simulation

Illustris simulation, showing the distribution of dark matter in 350 million by 300,000 light-years. Galaxies are represented by high density white dots (left) and normal baryonic matter (right). Credit: Markus Haider/Illustris

In a recent paper, Dr. Vagnozzi and Dr. Visinelli conducted a study to examine whether pure elastic scattering between dark energy and baryonic (aka normal) matter could leave a visible imprint in cosmological observations. They determined that this was not likely, at least when applied to observations sensitive to the linear evolution of cosmic structure, such as the cosmic microwave background (CMB) and large-scale structure clustering. at the linear level.

However, Dr. Vagnozzi also works with a Ph.D. student in Munich to extend this study and predict the implications of DE interaction with normal matter. Specifically, they want to examine the effect this would have on the nonlinear clustering of the large-scale structure of the Universe, as well as the structure of galaxies and galaxy clusters. Coupled with large-scale surveys, which will benefit from next-generation telescopes in the years to come, astronomers and cosmologists could be on the verge of shedding light on the “Dark Universe!”

Originally published on Universe Today.

To learn more about this research, read XENON1T Experiment May Have Detected Dark Energy.

Reference: “Direct Dark Energy Detection: XENON1T Excess and Future Prospects” by Sunny Vagnozzi, Luca Visinelli, Philippe Brax, Anne-Christine Davis and Jeremy Sakstein, September 15, 2021, Physical examination D.
DOI: 10.1103/PhysRevD.104.063023

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Wobbling in the history of particle physics – now. Powered by Northrop Grumman https://polkinghorne.org/wobbling-in-the-history-of-particle-physics-now-powered-by-northrop-grumman/ Mon, 18 Oct 2021 07:00:00 +0000 https://polkinghorne.org/wobbling-in-the-history-of-particle-physics-now-powered-by-northrop-grumman/ Particle physics is the quest to discover the fundamental components of the universe by analyzing, cataloging and measuring the particles that combine to create everything. It’s no easy task – the variety and variability of these physical firmaments makes them an ever-changing puzzle that can seem completely impenetrable until a new secret is unlocked. Now, […]]]>

Particle physics is the quest to discover the fundamental components of the universe by analyzing, cataloging and measuring the particles that combine to create everything. It’s no easy task – the variety and variability of these physical firmaments makes them an ever-changing puzzle that can seem completely impenetrable until a new secret is unlocked.

Now, new research on the muon – a small electron-like particle 200 times heavier than its negatively charged cousin – could pave the way for the particle’s next pivot: oscillations.

Standard operation procedure

To help make sense of the universe and how it works, scientists created the Standard Model. It was not an easy task either. As SciTechDaily notes, while the electron was discovered in 1897, the last element in the current framework – the Higgs boson – wasn’t confirmed until 2012.

The model makes it possible to reconcile three of the four fundamental forces: electromagnetism, the strong nuclear force and the weak nuclear force. It also highlights the role of quarks and leptons as the building blocks of all matter, including the familiar trio of protons, neutrons and electrons. Work on the Standard Model has shown that photons play a role in the transport of electromagnetism, while the strong force relies on gluons to ensure the stability of atomic nuclei and the weak force exploits W and Z bosons. to drive the powerful nuclear processes that keep stars burning for billions of years. year.

However, despite its usefulness, the standard model has a blind spot: gravity. While the model does an excellent job of describing which particles underlie the other three fundamental forces, gravity is conspicuously absent. This is because scientists have never been able to link a specific particle to the creation and distribution of gravity. While it plays a vital role in the workings of our universe – whether it’s counteracting the expansive tendencies of nuclear reactions within our sun or keeping our feet firmly planted on planet Earth – this apparently appealing operation simple has historically resisted deep understanding.

But new muon measurements could change all that.

Crack the code

What is important to remember from scientists – and particle physicists in particular – is that they are never satisfied with the status quo. Although the Standard Model provides a starting point for understanding the universe, obvious shortcomings in the current framework mean there is still work to be done. In practice, this work involves finding new approaches to potentially breaking the model by conducting experiments, taking measurements, and then comparing the results to what the model predicts.

The challenge? For years, the model has found the right answers, much to the frustration of physicists who know something is missing. Repeated experiments using different particle approaches have produced precise measurement after precise measurement – ​​so far. Recent follow-up work on earlier muon experiments using more advanced equipment suggests a crack in the current model and raises hope that scientists may finally have found the key to a new revolution in particle physics.

Meet the muon

So what exactly is a muon? Think electron, but heavier. Much heavier – 200 times heavier, in fact. As Science Daily notes, muons and electrons “are essentially tiny magnets with their own magnetic field.” However, unlike electrons, muons are much less stable, existing only a few millionths of a second before decaying. It is also difficult to observe muons, even during their brief stay here, because the vacuum they occupy is not empty.

“It’s your cappuccino-foam version of a vacuum, where there are virtual particles appearing and disappearing all the time,” Lawrence Gibbons, who led the Cornell team involved in the new research, told Science Daily. “And that turns out to affect the strength of a muon’s magnetic field.”

Through work at CERN in 1959, followed by more precise experiments in 1966 and 1969, and then another round at Brookhaven National Laboratory in 1999, the researchers finally found something: a disconnect between the observed magnetic measurements and predicted when the muons made their way into this void. New efforts at Fermilab with more precise and advanced equipment have confirmed these findings – and could pave the way for a much more massive muon impact.

Let’s Get Physics-al

Work at CERN, Brookhaven and Fermilab all focus on the same thing: the g-2 value of the muon, which represents the amount it “wobbles” via vacuum interactions. As Jessica Esquivel, a particle physicist at Fermilab, notes, this oscillation is called the precession frequency.

“When muons enter a magnetic field, they precess or spin like a top,” she told Vox.

To measure precession, efforts at Fermilab used a powerful particle accelerator – capable of creating 20 times more muons than those previously used at CERN – to shoot an intense beam of muons into highly sensitive detectors, which measured their precession frequency. As the Standard Model predicts, this precession occurs when muons collide with virtual particles, which Esquivel describes as “a kind of ghosting of real particles.”

“We have photons going in and out and they’re just kind of like there, but not really there,” she told Vox. However, despite this recurring strangeness, these virtual particles have a physical impact on muon oscillations.

But this is where it gets really weird: Experiments at Fermilab confirm that muons flicker more than they should, according to the Standard Model. Even more exciting? Scientists don’t know why.

Stumbling our way forward

The lack of certainty here is what makes these experimental results so interesting. According to the Standard Model, g-2 muon values ​​are explainable using actual particle interactions and should produce predictable results. However, Fermilab’s efforts suggest that something else is causing this additional oscillation – something outside the current functional framework, as Esquivel and his colleagues told Vox.

And while there have been discussions about this “breaking” of the Standard Model before, it’s more about filling in the details where the data was clearly missing. Esquivel likens it to adding elements to the periodic table.

“Even back then,” she tells Vox, “they had places where they knew an item had to go, but they hadn’t been able to see it yet. That’s basically where we are now. In practice, this movement of muons opens the door to a multitude of potential operations on the particles.This unexpected oscillation could be caused by an interaction with dark matter or long-predicted dark energy particles, or it could help establish a particle-based link with the peripheral fourth fundamental gravitational force.

Esquivel simply explains the impact of this measurement of movement: “It’s once in a lifetime. We are looking for new physics and we are so close that we can taste it. A meal of muons, an extra oscillation – it happens!

Being at the forefront of change, especially in space, physics and engineering, has been part of the Northrop Grumman culture for generations. Click here to search for jobs in these areas of scientific innovation.

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A physics experiment may have uncovered the mysterious force behind the expansion of the universe https://polkinghorne.org/a-physics-experiment-may-have-uncovered-the-mysterious-force-behind-the-expansion-of-the-universe/ Mon, 27 Sep 2021 07:00:00 +0000 https://polkinghorne.org/a-physics-experiment-may-have-uncovered-the-mysterious-force-behind-the-expansion-of-the-universe/ Representative image. | Photo credit: iStock Images What the universe is made up of at the most fundamental levels is a question that continues to both fascinate and frustrate scientists. The discovery of atoms, once thought to be nature’s smallest building blocks, paved the way for further study of subatomic particles such as electrons, protons […]]]>

Representative image. | Photo credit: iStock Images

What the universe is made up of at the most fundamental levels is a question that continues to both fascinate and frustrate scientists. The discovery of atoms, once thought to be nature’s smallest building blocks, paved the way for further study of subatomic particles such as electrons, protons and neutrons, which were found to be themselves made of particles. even smaller.

As our understanding of these particles grew, the Standard Model of particle physics was born. But after looking around the universe and measuring how widely galaxies are distributed and interact with each other, we soon realized that everything described in the Standard Model was only 5% of the matter in the universe.

What is the rest made up of, you ask? Well, we don’t really know, but about 27% of the universe, scientists are convinced, appears to be made up of something called dark matter – matter that doesn’t reflect any light but behaves similarly to normal matter. , exerting a force of gravity on everything around it.

As for the elements that make up the remaining 68% of the universe, our first clue came in the 1990s when scientists discovered that distant supernovae were fainter than their models had predicted. As more and more evidence came in, a new form of energy was theorized, one that exhibits properties that no other type of matter or radiation possesses – dark energy.

There’s next to nothing we can truly determine about the true nature of dark energy, but the measurements reveal one thing: it is remarkably uniform and constant across the universe, behaving fundamentally differently than other types of energy. energy.

It seems to be driving the expansion of the universe but, curiously, even as the volume of the universe increases, the energy density (of dark energy) remains constant. It is almost as if there is something uniformly present in space, the nature of which does not depend on anything residing in space. This prompted scientists to understand that dark energy could be a vast field that pervades the entire universe or even an inherent feature of spacetime itself.

A less explored theory though is that dark energy could be made up of particles we haven’t yet discovered, and that’s where the XENON1T experiment comes in. The XENON series of experiments were originally intended to search for theoretical dark matter particles that scientists call WIMPs. (massive particles interacting weakly).

Thousands of feet below Italy’s Gran Sasso mountain is a sensor-lined tank of 3.2 metric tons of pure xenon (chemically inert), forming a detector of unknown particles that can fly through the tank, causing ripples. The idea is that as these WIMPs move through xenon, they may occasionally hit a xenon nucleus, causing a brief flash of light that could be detected – what is called nuclear recoil.

But after years of not detecting nuclear recoil, scientists realized they could recalibrate their detector to look for electron recoil – phenomena where unknown particles collide with electrons rather than nuclei. of xenon. The researchers studied the first year’s worth of XENON1T data expecting to find 232 such setbacks – all caused by background contamination. But the experiment gave 285 – an excess of 53. It was confusing. What were these additional signals?

These findings have now led scientists to formulate three theories. The first of these – and obviously the most mundane – is that the result was an experimental hazard likely to wither away with improved accuracy and stats. The second is that some sort of unaccounted background contamination – possibly tritium in the water – may be causing these excess electron recoils.

The third, of which scientists say they are 95% certain, is the first-ever detection of an unknown type of dark energy particle that would require contortions of current particle physics theory. It’s clearly the most exotic of the three theories, but it may draw attention to a particular idea known as chameleon dark energy – a notion of a particle whose density is obscured in regions of the matter-rich spaces, but more noticeable in emptier regions. .

At the moment, however, this is only conjecture. A 95% confidence interval in physics is, after all, far from sufficient, and it is entirely possible that as the experimental framework refines, these findings may never happen again. But if substantiated, it would represent a giant step towards answering one of the greatest existential questions that have plagued humanity.

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A particle physics experiment could have directly observed dark energy https://polkinghorne.org/a-particle-physics-experiment-could-have-directly-observed-dark-energy/ Wed, 22 Sep 2021 07:00:00 +0000 https://polkinghorne.org/a-particle-physics-experiment-could-have-directly-observed-dark-energy/ About 25 years ago, astrophysicists noticed something very interesting about the Universe. The fact that it was expanding had been known since the 1920s, thanks to the observation of Edwin Hubble. But thanks to the observations that astronomers made with the space observatory that bore his name (the The Hubble Space Telescope), they began to […]]]>

About 25 years ago, astrophysicists noticed something very interesting about the Universe. The fact that it was expanding had been known since the 1920s, thanks to the observation of Edwin Hubble. But thanks to the observations that astronomers made with the space observatory that bore his name (the The Hubble Space Telescope), they began to notice how the rate of cosmic expansion was accelerating!

This led to the theory that the Universe is filled with an invisible and mysterious force, known as dark energy (DE). Decades after its proposal, scientists are still trying to pin down this elusive force that accounts for about 70% of the Universe’s energy budget. According to a recent study by an international team of researchers, the XENON1T experiment may have already detected this elusive force, opening new possibilities for future ED research.

The research was led by Dr Sunny Vagnozzi, a researcher at the Kavli Institute of Cosmology (KICC) at the University of Cambridge, and Dr Luca Visinelli, a Fellowship for Innovation (FELLINI) researcher (who is maintained with the support of the Marie Bourse Sklodowska-Curie) at the National Institute of Nuclear Physics (INFN) in Frascati, Italy. They were joined by researchers from the Institute for Theoretical Physics (IPhT), the University of Cambridge and the University of Hawaii.

Both DM and DE are part of the Lambda Cold Dark Matter (LCDM) model of cosmology, which posits that the Universe is filled with cold, slow-moving (DM) particles that interact with normal matter via the force of gravity alone. Lambda represents DE, which accelerates the expansion of the Universe. Since they are only discerned by observing their effect on the large-scale structure of the Universe, conventional thought holds that none of the forces interact with normal matter via electromagnetism or the weak or strong nuclear force. .

However, some DM theories posit that there is some level of interaction with visible matter, which researchers are actively testing. However, instead of more test results, astrophysicists and cosmologists still don’t know how DE fits into the physical laws that govern the Universe. Candidates so far include a modification of Einstein’s general relativity (GR), the presence of a new field, or a cosmological constant (CC). As Dr. Visinelli told Universe Today via email:

“For this reason, dark energy is perhaps even more mysterious than dark matter. We are seeing the effects of dark energy across a number of observations, starting with the seminal work on 1A supernovae in as standard candles. Assuming that dark energy is indeed a field, the quanta associated with it would be extremely light and carry very little energy. This is the reason why very little work has been done on this type of searches.

Their work is based on new research that goes beyond the standard LCDM model of cosmology to consider that DE interacts with light by affecting its properties (i.e. polarization, color, direction ). However, these interactions could be subject to screening mechanisms that prevent local experiments from detecting them. In this model, it is predicted that dark energy quanta can be produced in the Sun.

The XENON1T detector, shown below. Credit: XENOX Collaboration.

As Dr. Vagnozzi explained, the possible connection between screening and dark energy first came to him when he was taking a shower one day:

“I remember it was June 20 and I was taking a shower and thinking about solar axions (without) explaining XENON, and I realized the obvious solution was screening, because that would stop production in the denser stars. The screening is usually associated with dark energy and/or altered gravity patterns, and it just clicked.

I immediately WhatsApped Luca and we started working on it immediately (and reached out to our other co-authors who are experts in dark energy/modified gravity patterns).

For the purposes of their study, the team led by Dr. Vagnozzi and Dr. Visinelli reviewed data published by the XENON Collaboration, a DM research team made up of 135 researchers from 22 institutions around the world. At the heart of their experiment is a 3,500 kg (7,715 lb) detector of ultra-radio-pure liquid xenon housed in a 10 m (32.8 ft) tank of water. Located at the INFN Laboratori Nazionali del Gran Sasso, XENON is also the most sensitive dark matter (DM) experiment ever performed.

In 2020, the Collaboration published the results of its experimental campaign (2016 to 2018), which showed an unexpected rate of electronic recoil events. According to the collaboration, this did not constitute a detection of DM but could be explained by a tiny residual quantity of tritium in the experiment, the existence of a new particle (such as the solar axion), or an unexplained property of the neutrinos.

The upper PMT network with all the electrical cables. Credit: XENON Dark Matter Project

However, for the purposes of their study, the team led by Vagnozzi and Visinelli speculated that this may have been the first direct detection of DE. Said Vagnozzi:

“In our model, dark energy has special properties: its mass term is related to the density of the environment, so denser materials would shield the effects of dark energy, while denser environments light such as intergalactic space would allow for long range dark energy.

“In this model called “chameleon”, dark energy quanta are produced in the region of the Sun in which the electromagnetic field is strongest, the tachocline, which is the region in which the transport of energy to the interior of the Sun goes from the radiative transition to the convection.The high energy density of the electromagnetic radiation in the region allows a strong coupling with the chameleon field and its production.

If true, this would mean that experiments around the world currently focused on dark matter research could also be devoted to the hunt for dark energy. To that end, Dr. Vagnozzi and Dr. Visinelli hope that this study will spark interest in particle models of ED and that the search for these elusive particles can be conducted in parallel with ongoing DM research. At the very least, these experiments will test theories about ED that go beyond the LCDM model, helping scientists narrow the list of candidates. Says Dr. Visinelli:

“Many other experiments designed for Dark Matter may also contain information about these chameleons, and we hope that the design of future setups for this research will be considered. An independent test using cosmological data crossed with the predictions of the chameleon model would also be necessary. As for us, we plan to refine our paper’s calculations using a solar model, study chameleon production in massive stars, and get in touch with experimentalists for updates.

Illustris simulation, showing the distribution of dark matter in 350 million by 300,000 light-years. Galaxies are represented by high density white dots (left) and normal baryonic matter (right). Credit: Markus Haider/Illustris

In a recent paper, Dr. Vagnozzi and Dr. Visinelli conducted a study to examine whether pure elastic scattering between dark energy and baryonic (aka normal) matter could leave a visible imprint in cosmological observations. They determined that this was not likely, at least when applied to observations sensitive to the linear evolution of cosmic structure, such as the cosmic microwave background (CMB) and large-scale structure clustering. at the linear level.

However, Dr. Vagnozzi also works with a Ph.D. student in Munich to extend this study and predict the implications of DE interaction with normal matter. Specifically, they want to examine the effect this would have on the nonlinear clustering of the large-scale structure of the Universe, as well as the structure of galaxies and galaxy clusters. Coupled with large-scale surveys, which will benefit from next-generation telescopes in the years to come, astronomers and cosmologists could be on the verge of shedding light on the “dark universe”!

Further reading: physical examination D

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