Scientists approved a blueprint for the next two decades of particle physics in the U.S. on Friday. It aims to restore American primacy in high energy particle physics.
The new strategy calls on physicists to begin laying the groundwork for a revolutionary particle collider that could be built on American soil. The machine would collide tiny, point-like muons, which resemble electrons but are more massive. Muons provide more bang for the buck than the protons used in the Large Hadron Collider at CERN, and would push the search for new forces and particles deeper than ever into the unknown.
The siting of such a project, perhaps at the Fermi National Accelerator Laboratory in Illinois, would restore American particle physics to a position of pre-eminence that was ceded to Europe in 1993 when Congress canceled the giant Superconducting Super Collider. But it will take at least 10 years to demonstrate that the muon collider could work and how much it would cost.
“This is our muon shot,” the committee, charged with outlining a vision for the next decade of American particle physics, said in a report titled “Exploring the Quantum Universe: Pathways to Innovation and Discovery in Particle Physics.” It was presented and discussed at a meeting in Washington, D.C., on Thursday and Friday, and will be discussed further at Fermilab next week.
The report also highlighted a need to invest in next-generation experiments probing the nature of subatomic particles called neutrinos; the cosmic microwave background, relic radiation from the Big Bang; and dark matter, the gravitational glue holding galaxies together. The panel also recommended participating in a future facility in either Europe or Japan, dedicated to studying the Higgs boson, the discovery of which in 2012 was key for understanding how other particles get their mass.
“The size of the universe we now see as 14 billion light-years across was actually smaller than the size of a nucleus” early in cosmic time, said Hitoshi Murayama, a physicist at the University of California, Berkeley, who led the committee. “So our field is actually not just looking for the fundamental constituents, but getting a bigger picture of how the universe works as whole.”
The committee, formally known as the Particle Physics Project Prioritization Panel, or P5, was tasked by the U.S. Department of Energy and the National Science Foundation to lay out a road map for the future of the field. The three-year process began by soliciting input from the particle physics community at large, and the final report will serve as a recommendation for what national agencies should prioritize over the next decade.
The last P5 report, “Building for Discovery: Strategic Plan for U.S. Particle Physics in the Global Context,” was published in 2014 on the heels of the Higgs boson discovery. That was a tremendous success for the Standard Model, a suite of quantum equations that explains everything that scientists know and test in the laboratory about the forces and particles in nature, and which has reaped numerous Nobel Prizes for its originators.
But the Standard Model has nothing to say about gravity and thus about black holes or the “dark energy” that is pushing the universe apart. Nor does it explain dark matter, the invisible matter swaddling galaxies. Nor, for that matter, does it explain the Higgs.
In the last decade, physicists have made little progress on these fronts. They have failed to identify dark matter, and some of their most popular hypotheses, particularly a notion called supersymmetry, are on the verge of being ruled out.
The process of building a report for the next decade included the Seattle Snowmass Summer Study in 2022, for which physicists submitted hundreds of papers proposing future initiatives in the field. A summary of the study was compiled into a 700-page book. “I characterize this really as democracy at work,” Dr. Murayama said, referring to it as a “bottom-up” process.
Sally Seidel, a physicist at the University of New Mexico and chair of the Department of Energy’s High Energy Physics Advisory Panel, described the process as “a remarkable display of curiosity” that brought together thousands of researchers. “I cannot recall a more exciting time to explore particle physics,” she wrote in an email.
Recommendations by the P5 committee took into account two budget scenarios given to them by the U.S. Department of Energy. In one “base line” case the department’s budget is expected to rise by 3 percent a year, basically keeping up with inflation. In this scenario, the committee emphasized pursuing major projects like a system of telescopes in Chile and Antarctica to study the cosmic microwave background, the realization of an offshore Higgs factory and a scaled-up version of IceCube, an observatory frozen in the ice of the South Pole that captures neutrinos from exotic sources in the universe.
With this budget scenario, there would also be room to support the vision for a particle collider based in the United States.
Particle colliders like the CERN machine get their oomph from Einstein’s revelation that energy and mass are interchangeable. The more energy released in a collision, the more massive the particles that can be made. Because protons are messy bags of smaller particles known as quarks and gluons, smashing them together releases only a fraction of the proton’s total energy. Muons, on the other hand, are elementary; with no internal constituents (as far as scientists know), their collisions harness more energetic results.
A muon collider is one of three options being considered as the successor to CERN’s Large Hadron Collider, which is currently the largest collider in the world and is expected to dominate particle physics for the next decade. China and CERN have each explored building a new collider 60 miles or so in circumference, which would reach collision energies of 100 trillion electron volts compared with the Large Hadron Collider’s 14 trillion, opening up vistas of energy and time.
Another possibility, which in principle could be performed on a table top rather than in miles of underground tunnels, is called wake field acceleration, in which the particle is propelled like a surfer on waves of highly ionized gas, a plasma.
Toyoko Orimoto, a physicist at Northeastern University, found these recommendations ambitious and exciting. “The next 10 years are going to be a very thrilling time for particle physics,” she said.
The report also considered a grimmer budget scenario consisting of only a 2 percent yearly increase in funds, which would amount to an effective cut in support. In that case, the committee said, the United States would have to abandon hopes of hosting a next-generation dark-matter experiment in a new underground laboratory in South Dakota and scratch planned upgrades to the already-expensive, ongoing construction of the Deep Underground Neutrino Experiment, or DUNE, further diminishing the nation’s leadership in those areas.
“The U.S. will have to cede leadership in certain areas in particle physics,” said Karsten Heeger, a physicist at Yale University who is the P5 deputy chair. “That would be an impact that would be felt in the field, and beyond.”
Failing all of that, the report urges the federal government to stay the course on projects to which it is already committed, including cranking up the luminosity, or collision rates, of the Large Hadron Collider for deeper studies of the Higgs and other rare phenomena; continuing construction of the Vera C. Rubin Observatory, a telescope in Chile designed to create time-lapse movies of the cosmos; and a limited version of DUNE.
“They did what they had to do,” Lisa Randall, a physicist at Harvard who was not part of the P5 committee, said, producing a hopeful vision for the future while preparing to weather what could be fraught budgets right now.
Michael Turner, a retired cosmologist from the University of Chicago, and Maria Spiropulu of the California Institute of Technology, who are leading a related study for the National Academy of Sciences, called it “a bold plan” in a joint emailed statement.
Because the lifetimes of these projects span decades, the committee emphasized support for early-career scientists who will eventually take over the projects. “They are the future,” Dr. Murayama said.
Up-and-coming physicists are excited about the endorsement. “As someone who still has the better part of her career in front of her, this is the kind of field I want to be a part of,” said Tova Holmes, a physicist at the University of Tennessee who has been working on muon collider designs. “One with big ambitions that tries new things, develops new technologies and believes in its own potential.”
The committee will pivot its focus to gaining support for the plan, both within and outside of the physics community. In particular, Dr. Murayama hoped it would grab the attention of staff members who communicate with members of Congress about how to vote on the department’s budget.
“Basic research is a tough sell,” Dr. Murayama said. “It’s not an immediate benefit to society.” But the payoff is worth it, he added: Particle physics has led to revolutions in medical applications, materials science, and even the creation of iPhones and the World Wide Web.
But according to Dr. Murayama, the benefits transcend the impact the field has on society. “Particle physics is really at the heart of what we are, who we are,” he said, adding that all of us, physicist or not, “would like to understand why we exist, where we came from and where we’re going.”
The post Particle Physicists Agree on a Road Map for the Next Decade appeared first on New York Times.
Wanasayansi wa Marekani wamekubaliana na mpango wa miaka 20 ijayo ya sayansi ya chembe za nyuklia. Lengo lake ni kurudisha cheo cha kwanza cha Marekani katika fizikia ya chembe za nishati ya juu. Mfumo huo mpya unawaomba wanasayansi wa fizikia kuanza kuweka msingi wa mashine ya kuangusha chembechembe ambayo inaweza kujengwa nchini Marekani. Mashine hiyo ingegongana na muoni ndogo-ndogo, zinazofanana na elektroni lakini zenye uzito mkubwa zaidi. Muoni ni mojawapo ya chembe za nyuklia zinazotumiwa katika mashine ya kuunganisha nyuklia ya CERN, na zinasaidia kuendeleza utafiti wa nyuklia mpya. "Kutengenezwa kwa mradi huo, labda katika Maabara ya Kitaifa ya Fermi Accelerator huko Illinois, kungerudisha fizikia ya chembe za chembe za Amerika katika nafasi ya kipaumbele ambayo ilitolewa kwa Ulaya mnamo 1993 wakati Bunge lilipofutilia mbali Superconducting Collider kubwa.""" Lakini itachukua angalau miaka 10 kuonyesha kwamba kiunganishi cha muon kinaweza kufanya kazi na ni kiasi gani cha gharama. "Hii ni risasi yetu ya muon, ""kamati hiyo, iliyowajibika kwa kuelezea maono kwa muongo ujao wa fizikia ya chembe za Amerika, ilisema katika ripoti iliyoitwa ""Kuchunguza Ulimwengu wa Quantum: Njia za Ubunifu na Ugunduzi katika Fizikia ya Chembe za Chembe"" Ilitolewa na kujadiliwa katika mkutano huko Washington, DC, Alhamisi na Ijumaa, na itajadiliwa zaidi katika Fermilab wiki ijayo." Ripoti hiyo pia ilionyesha haja ya kuwekeza katika majaribio ya kizazi kijacho ya kuchunguza asili ya chembechembe za subatomic zinazoitwa neutrinos, asili ya cosmic microwave, mionzi ya mabaki kutoka kwa Big Bang, na nyenzo nyeusi, gundi ya mvuto inayounganisha galaksi. "Kundi hilo pia lilipendekeza kushiriki katika kituo cha baadaye katika Ulaya au Japan, kujitolea kusoma Higgs boson, ambayo ugunduzi katika 2012 ilikuwa muhimu kwa kuelewa jinsi chembe nyingine kupata wingi wao. """ """Ukubwa wa ulimwengu ambao sasa tunauona kama miaka ya mwanga bilioni 14 kwa kipenyo ulikuwa mdogo kuliko ukubwa wa nyuklia mapema katika wakati wa ulimwengu,"" alisema Hitoshi Murayama, mwanafizikia wa Chuo Kikuu cha California, Berkeley, ambaye aliongoza kamati hiyo." "Kwa hivyo, uwanja wetu sio tu kutafuta vipengele vya msingi, lakini kupata picha kubwa ya jinsi ulimwengu unavyofanya kazi kwa ujumla. "" - Kamati ya Uteuzi wa Utaratibu wa Mradi wa Fizikia ya Chembe, au P5, ilipewa kazi na Idara ya Nishati ya Marekani na Shirika la Sayansi la Kitaifa kuweka ramani ya barabara kwa siku zijazo za uwanja huo." Utaratibu wa miaka mitatu ulianza kwa kuomba maoni kutoka kwa jamii ya fizikia ya chembe kwa ujumla, na ripoti ya mwisho itatumika kama pendekezo kwa kile mashirika ya kitaifa yanapaswa kuweka kipaumbele katika muongo ujao. P5: Ujenzi kwa ajili ya Ugunduzi: Mpango wa Mkakati kwa ajili ya Marekani "Kutoka kwa kitabu chake ""Particle Physics in the Global Context"" cha mwaka 2014 na ""The Higgs boson"" cha mwaka 2014." Hii ni mafanikio makubwa kwa Standard Model, seti ya equations quantum kwamba anaelezea kila kitu wanasayansi kujua na mtihani katika maabara kuhusu nguvu na chembe katika asili, na ambayo imepata tuzo nyingi za Nobel kwa ajili ya waanzilishi wake. Lakini Mfano wa Kiwango hauna chochote cha kusema kuhusu mvuto na kwa hiyo kuhusu mashimo meusi au "nishati nyeusi" ambayo inaisukuma ulimwengu mbali. Wala haionyeshi jambo jeusi, jambo lisiloonekana linalofunika magalaksi. Wala, kwa habari hiyo, haionyeshi Higgs. Katika mwongo uliopita, wanasayansi wamefanya maendeleo machache katika mambo hayo. "Wanafunzi hawajaweza kutambua ""dutu nyeusi"" na baadhi ya nadharia zao maarufu, hasa nadharia inayoitwa ""supersymmetry,"" ziko karibu kuondolewa." Katika utafiti wa mwaka wa 2022, Seattle Snowmass Summer Study, wataalamu wa fizikia waliwasilisha mamia ya karatasi zinazopendekeza mipango ya baadaye katika uwanja huo. Maelezo ya utafiti huo yalichapishwa katika kitabu chenye kurasa 700. "Mimi hufafanua hii kweli kama demokrasia kazini", Daktari Murayama alisema, akirejelea kama mchakato wa "chini-juu". Sally Seidel, mwanafizikia katika Chuo Kikuu cha New Mexico na mwenyekiti wa Idara ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati ya Nishati. "Siwezi kukumbuka wakati wa kusisimua zaidi kuchunguza fizikia ya chembe", aliandika katika barua pepe. """P5C imependekeza kuunda bajeti ya nchi mbili ambazo hazina bajeti, na pia imependekeza kuunda bajeti ya nchi mbili ambazo hazina bajeti, na kuanzisha bajeti ya nchi mbili ambazo hazina bajeti." Katika kesi moja ya "mstari wa msingi" bajeti ya idara inatarajiwa kuongezeka kwa asilimia 3 kwa mwaka, kimsingi kuendelea na mfumuko wa bei. Katika hali hii, kamati hiyo ilisisitiza kufuatilia miradi mikubwa kama mfumo wa darubini huko Chile na Antaktika kusoma nyuma ya cosmic microwave, utambuzi wa kiwanda cha Higgs cha pwani na toleo la upanuzi wa IceCube, kituo cha uchunguzi kilichohifadhiwa kwenye barafu ya Ncha ya Kusini ambacho kinakamata neutrino kutoka vyanzo vya kigeni katika ulimwengu. Kwa hali hii ya bajeti, pia kutakuwa na nafasi ya kuunga mkono maono ya collider ya chembe iliyoko Marekani. Vifaa vya kushambulia chembechembe kama vile mashine ya CERN vinapata nguvu zao kutokana na ufunuo wa Einstein kwamba nishati na wingi vinaweza kubadilishana. Kadiri nishati inavyotolewa katika mgongano, ndivyo chembe zenye uzito mkubwa zaidi zinavyoweza kutokezwa. Kwa sababu protoni ni mifuko ya chembe ndogo inayoitwa quark na gluon, kuzipiga pamoja hutokeza sehemu ndogo tu ya nishati ya protoni. Muoni, kwa upande mwingine, ni za msingi; bila vipengele vya ndani (kwa kadiri wanasayansi wanavyojua), mgongano wao hutumia matokeo yenye nguvu zaidi. Kiwanda cha kuunganisha vipimo vya muoni (MUC) ni mojawapo ya vifaa vitatu vinavyotarajiwa kuwa mrithi wa kiwanda cha kuunganisha vipimo vya CERN (Large Hadron Collider), ambacho kwa sasa ni kiwanda kikubwa zaidi duniani na kinatarajiwa kutawala fizikia ya chembe katika muongo ujao. China na CERN zimechunguza kujenga collider mpya ya kilomita 60 au zaidi kwa mduara, ambayo itafikia nishati ya mgongano wa volti za elektroniki za trilioni 100 ikilinganishwa na 14 trilioni ya Large Hadron Collider, ikifungua maono ya nishati na wakati. "Uwezekano mwingine, ambao kwa kanuni unaweza kufanyika juu ya meza badala ya katika maili ya handaki chini ya ardhi, inaitwa ""kuongeza kasi ya uwanja wa kufuatilia,"" ambapo chembe ni propelled kama surfer juu ya mawimbi ya gesi ionized sana, plasma." Toyoko Orimoto, mwanafizikia wa Chuo Kikuu cha Northeastern, aliona mapendekezo hayo kuwa yenye kutamaniwa na yenye kusisimua. "Miaka kumi ijayo itakuwa wakati wa kusisimua sana kwa fizikia ya chembechembe, ""alisema." Ripoti hiyo pia ilizingatia hali mbaya zaidi ya bajeti inayojumuisha ongezeko la asilimia mbili tu ya kila mwaka katika fedha, ambayo ingekuwa kiasi cha kupunguzwa kwa msaada. "Kama hivyo, kamati hiyo imesema, Marekani ingelazimika kuacha matumaini ya kuandaa jaribio la kizazi kijacho cha ""dutu nyeusi"" katika maabara mpya ya chini ya ardhi huko South Dakota na kukomesha upgrades zilizopangwa kwa ujenzi wa ""Deep Underground Neutrino Experiment"" (DUNE) unaoendelea, na kupunguza zaidi uongozi wa taifa katika maeneo hayo." "Mashirika ya kimataifa ya fizikia yamekuwa yakijaribu kuimarisha uwezo wa kuongoza katika masuala ya fizikia ya chembe ndogo za chembe,"" alisema Karsten Heeger, mwanasayansi wa fizikia katika Chuo Kikuu cha Yale ambaye ni makamu mwenyekiti wa P5. """ "Hii ni kwa sababu ya ""mfano wa kuvutia"" wa uchunguzi wa Higgs na matukio mengine ya nadra, kama vile uchunguzi wa kina wa Higgs na matukio mengine ya nadra, na ujenzi wa Veracruz Rubin Observatory, darubini iliyoundwa nchini Chile kuunda filamu za muda wa cosmos, na ""Dune.""" "Walifanya kile walichopaswa kufanya,"" Lisa Randall, mwanafizikia wa Harvard ambaye hakuwa sehemu ya kamati ya P5, alisema, akitoa maono ya matumaini kwa siku zijazo wakati wa kujitayarisha kukabiliana na kile ambacho kinaweza kuwa bajeti ngumu sasa hivi." Michael Turner, mtaalamu wa ulimwengu aliyestaafu kutoka Chuo Kikuu cha Chicago, na Maria Spiro-Polo, wa Taasisi ya Teknolojia ya California, ambao wanaongoza utafiti unaohusiana na Chuo Kikuu cha Sayansi cha Taifa, waliuita "mpango wa ujasiri" katika taarifa ya pamoja iliyotumwa kwa barua pepe. Kwa sababu maisha ya miradi hii huchukua miongo kadhaa, kamati ilisisitiza msaada kwa wanasayansi wa kazi ya mapema ambao hatimaye watachukua miradi hiyo. "Wao ndio wakati ujao", Dakt. Murayama akasema. Wanafizikia wanaotarajia kuwa wataalamu wanafurahi sana kwa sababu ya utegemezo huo. "Kama mtu ambaye bado ana sehemu bora ya kazi yake mbele yake, hii ni aina ya uwanja nataka kuwa sehemu ya, ""alisema Tova Holmes, mwanafizikia katika Chuo Kikuu cha Tennessee ambaye amekuwa akifanya kazi juu ya miundo ya muon collider." "Kama mtu mwenye tamaa kubwa, anayejaribu mambo mapya, anaendeleza teknolojia mpya na anaamini uwezo wake mwenyewe, kamati hiyo itazingatia kupata msaada kwa mpango huo, ndani na nje ya jamii ya fizikia.""" "Mwanamkubwa Murayama amesema kuwa ""tunaamini kwamba hilo litakuwa jambo la muhimu kwa wafanyakazi ambao wanawasiliana na wabunge kuhusu jinsi ya kupiga kura juu ya bajeti ya idara hiyo.""" "Utafiti wa msingi ni ngumu kuuza", alisema Dakt. Murayama. "Si faida ya papo hapo kwa jamii. ""Lakini malipo ni thamani yake, aliongeza: Fizikia ya chembe imesababisha mapinduzi katika matumizi ya matibabu, sayansi ya vifaa, na hata uundaji wa iPhones na World Wide Web. """ Lakini kulingana na Dakt. Murayama, faida hizo zinazidi athari za uwanja huo kwa jamii. "Fizikia ya chembe ni kweli katika moyo wa kile sisi ni, ambaye sisi ni, "alisema, akiongeza kwamba sisi sote, mwanafizikia au si, "ngependa kuelewa kwa nini tuko, ambapo sisi alikuja kutoka na ambapo sisi ni kwenda. " The post Chembe Wanafizikia kukubaliana juu ya Ramani ya Barabara kwa Decade ijayo alionekana kwanza juu ya New York Times.