Neutrino barbashi: definition, Properties, bayanin. neutrino oscillations - shi ...

Neutrino - wani na farko barbashi cewa ya yi kama da electron, amma ba ta da wutar lantarki. Yana yana da matukar kananan taro, wanda zai iya zama ko sifili. Daga taro na neutrino dogara a kan gudun. Bambanci a lokacin isowa da barbashi katako ne 0,0006% (± 0,0012%). A shekarar 2011, aka kafa shi a lokacin Opera gwaji cewa gudu ya wuce gudun haske neutrinos, amma mai zaman kanta da wannan kwarewa da ya ba ta tabbatar.

A elusive barbashi

Wannan shi ne daya daga cikin na kowa barbashi a sararin samaniya. Tun da shi interacts sosai kadan da al'amarin, shi ne wuce yarda da wuya a gane. Electrons da neutrinos ba su shiga a cikin karfi da makaman nukiliya da karfi, amma daidai shiga a cikin rauni. Barbashi da ciwon irin kaddarorin da aka kira leptons. Bugu da kari ga electron (positron da antiparticle), kira da cajin leptons muon (200 electron taro), tau (3500 electron taro), kuma su antiparticle. Suna da ake kira: electron, muon da tau neutrinos. Kowace daga cikinsu yana antimaterial bangaren, da ake kira mai antineutrino.

Muon da tau, kamar wani electron, da rakiyar barbashi. Yana muon da tau neutrinos. Iri uku na barbashi daban-daban daga juna. Alal misali, lokacin da muon neutrinos hulɗa tare da manufa, da suka ko da yaushe nuna muons kuma ba tau ko electrons. A dauki na barbashi, ko da yake electrons da electron neutrinos aka halitta da kuma hallaka, su ware Naira Miliyan Xari zauna canzawa. Wannan hujja take kaiwa zuwa wani rabuwa leptons cikin iri uku, kowanne daga abin da ya mallaka a caje leptons da rakiyar neutrino.

Don gane da wannan barbashi ake bukata a manya-manyan da kuma sosai m gane. Matsayin mai mulkin, tare da low makamashi neutrinos zai yi tafiya domin da yawa haske shekaru da hulda da al'amarin. Saboda haka, duk ƙasa gwaje-gwajen da su dõgara a kan ji na karamin sulusi da murabba'i cewa interacts da Registrars m size. Alal misali, a cikin wani neutrino Observatory Sudbury, dauke da 1,000 ton na nauyi ruwa ya wuce ta injimin gano illa game da 1012 da hasken rana neutrinos da na biyu. Kuma same kawai 30 a kowace rana.

Tarihi na samu

Wolfgang Pauli farko tsara da wanzuwar barbashi a 1930. A wannan lokacin, akwai wani matsala, domin ya zama kamar ma cewa makamashi da kuma mai kusurwa lokacinta ba adana a cikin beta lalace. Amma Pauli ya nuna cewa, idan akwai ba, wanda ake jefarwa neutrinos hulda tsaka tsaki barbashi, da samar da makamashi kiyayewa dokar za a kiyaye. Italian likita Enrico Fermi a 1934 ɓullo da ka'idar beta lalata, da kuma ya ba ta sunan barbashi.

Duk da dukan tsinkaya domin shekaru 20, neutrinos ba za a iya gano gwaje saboda ta raunana hulda da al'amarin. Saboda barbashi an electrically caje, ba su yi aiki da electromagnetic sojojin, kuma, saboda haka, ba su sa ionization na abu. Bugu da ƙari, suka amsa tare da abu kawai ta hanyar rauni interactions kadan karfi. Saboda haka, su ne mafi iya shiga subatomic barbashi iya wucewa ta hanyar wata babbar lamba na kwayoyin halitta ba tare da haddasa wani dauki. Kawai 1 zuwa biliyan 10 na wadannan barbashi tafiya ta hanyar da masana'anta da nesa daidaita da diamita na Duniya, ya mayar da protons ko neutron.

A karshe, a shekara ta 1956, wata ƙungiya daga American lissafin kimiyya, jagorancin Frederick Reines ruwaito da samu na electron antineutrino. A gwaje-gwajen da shi antineutrinos radiated nukiliya reactor, maida martani da wani proton, forming neutrons da positrons. Musamman (da kuma rare) makamashi sa hannu na karshen da-kayayyakin da aka shaida akan wanzuwar na barbashi.

Bude cajin leptons muons aka masomin m ganewa na biyu da irin neutrinos - muon. Su ganewa aka za'ayi a 1962 a kan tushen da sakamakon da gwajin a barbashi totur. High-makamashi muons lalata neutrinos kafa ta pi-mesons da kuma directed zuwa injimin gano illa don haka da cewa shi yiwuwa a jarraba su dauki da abu. Duk da cewa su ne wadanda ba amsawa, kazalika da sauran iri gaɓũɓuwa, an gano cewa, a cikin rare lokuta a lõkacin da suka amsa tare da protons ko neutrons, muons, neutrinos muons, amma ba electrons. A 1998, Amirka lissafin kimiyya Leon Lederman, Melvin Schwartz da Dzhek Shteynberger aka bayar da Nobel Prize a kimiyyar lissafi domin ganewa na muon-neutrinos.

A cikin tsakiyar 1970s, da neutrino kimiyyar lissafi tsiwirwirinsu wani irin cajin leptons - tau. Tau-neutrino da tau-antineutrinos aka hade da wannan na uku cajin lepton. A shekarar 2000, lissafin kimiyya a National totur Laboratory. Enrico Fermi ruwaito farko gwaji shaidar kasancewar wannan irin barbashi.

nauyi

All iri neutrinos da taro, wanda shi ne da yawa kasa da cewa su abokan caje. Alal misali, gwaje-gwajen nuna cewa, taro na electron-neutrino dole ne kasa da 0,002% na electron taro da kuma Naira Miliyan Xari da talakawa na uku iri ya zama kasa da 0,48 EV. A tunani na shekaru masu yawa da cewa taro na barbashi ne sifili, ko da yake babu tursasawa msar tambayar shaida, me ya sa shi ya zama wannan hanya. Sa'an nan, a 2002, da Sudbury Neutrino Observatory aka samu da farko kai tsaye shaida cewa electron neutrinos jefarwa da makaman nukiliya a cikin halayen da zuciyar rãnã, muddin suka wuce, ta hanyar da shi, canja da irin. Irin wannan "oscillations" neutrino yiwu idan daya ko fiye daga cikin barbashi da kananan taro. Da karatu da hulda da cosmic haskoki a cikin yanayin duniya ma nuna gaban taro, amma kara gwaje-gwajen da ake bukata don more daidai ayyana shi.

kafofin

Halitta kafofin na neutrinos - a rediyoaktif lalata da abubuwa a cikin ƙasa, wanda aka jefarwa a manyan kwarara daga low-makamashi electron-antineutrino. Supernovae ne ma advantageously neutrino sabon abu, tun wadannan barbashi iya kawai shiga hyperdense abu kafa a wata rugujewa star. kawai karamin sashi na makamashi ne tuba zuwa ga haske. Lissafi nuna cewa game da 2% na makamashin hasken rana - makamashi neutrinos kafa a halayen da thermonuclear fe. Shi ne wata ila cewa mafi yawan duhu al'amari na duniya da aka yi sama da neutrinos samar a lokacin Big Bang.

kimiyyar lissafi matsaloli

Areas alaka neutrino astrophysics, da kuma bambancin da hanzari gwamnatin. Yanzu al'amurran da suka shafi cewa jawo hankalin babban adadin gwaji da kuma ka'idojin kokari, wadannan:

• Mene ne daban-daban neutrino talakawa?
• Ta yaya suka shafi cosmology, Big Bang?
• suka oscillate?
• Can daya irin neutrino jũya a cikin wani matsayin da suka yi tafiya ta hanyar al'amarin da sarari?
• Shin neutrinos fundamentally daban-daban da su daga antiparticles?
• Yadda Stars durkushe don samar da wani supernova?
• Mene ne muhimmancin neutrinos a cosmology?

Daya daga cikin longstanding matsaloli na musamman sha'awa ne ake kira da hasken rana neutrino matsala. Wannan sunan yana nufin cewa a lokacin da dama terrestrial da gwaje-gwaje a cikin past shekaru 30, ci gaba da lura da barbashi karami fiye zama dole don samar da makamashi radiated da rana. Daya zai yiwu bayani ne oscillation, watau. E. The canji na electron neutrinos zuwa muon ko tau a lokacin tafiya zuwa Earth. To, yãya fiye da wuya a gwada low-makamashi muon ko tau neutrinos, irin wannan canji zai bayyana dalilin da ya sa ba mu ganin dama adadin na barbashi a Duniya.

Fourth Nobel Prize

Nobel Prize a Physics 2015 aka bayar ga Takaaki Kaji kuma Arthur MacDonald ga ganewa na neutrino taro. Wannan shi ne karo na hudu irin wannan lambar yabo hade tare da gwaji ma'aunai na wadannan barbashi. Wani zai iya zama sha'awar wannan tambaya na sa ya kamata mu kula sosai game da wani abu da kawai hulɗa tare da talakawa al'amarin.

Gaskiyar cewa za mu iya gane wadannan ephemeral gaɓũɓuwa, shi ne wasiya ga mutum dabara. Tun da dokoki na jimla makanikai, probabilistic, mun san cewa, duk da cewa kusan dukkan neutrinos ratsa cikin Duniya, wasu daga cikinsu za su yi mu'amala da shi. A injimin gano illa da yake iya isasshe manyan size aka rajista.

A farko wannan na'urar da aka gina a cikin sittin, zurfi a cikin wani mine a South Dakota. A shaft da aka cika a 400 dubu. L tsabtace ruwa. A kan talakawan daya barbashi neutrino kullum interacts da zarra na chlorine, tana mayar da shi zuwa argon. Wuce yarda, Raymond Davis, wanda ya alhakin injimin gano illa, ƙirƙira wani hanya domin ganewa na mahara argon kwayoyin halitta, da kuma hudu bayan shekaru da dama, a 2002, domin wannan ban mamaki injiniya feat ya aka bayar da kyautar Nobel.

sabon ilmin taurari

Saboda neutrinos mu'amala haka weakly, ba za su iya tafiya mai nisa. Sun ba mu da wani hango a cikin wuraren da cewa in ba haka ba za mu taba gani. Neutrinos gano Davis, kafa a sakamakon nukiliya halayen da ya faru a cikin zuciya na rãnã, kuma sun iya barin wannan wuce yarda da m da zafi wurin zama kawai domin ba su hulɗa tare da wasu kwayoyin halitta. Za ka iya har ma gane neutrinos jefarwa daga tsakiyar wani fashe star a nesa na fiye da dubu dari haske-shekara daga Earth.

Bugu da kari, wadannan barbashi sa ya yiwu don tsayar da sararin samaniya a sosai kananan sikelin, da yawa karami bisa ga waɗanda a wanda za a iya duba cikin Manyan Hadron Collider a Geneva, ya gano Higgs boson. Yana da wannan dalilin cewa Nobel kwamitin yanke kyautar Nobel Prize for gano neutrino na wani irin.

m karancin

Lokacin Ray Davis ya lura da hasken rana neutrinos, ya samu ne kawai na uku daga cikin sa ran yawa. Mai lissafin kimiyya yi imani da cewa dalilin wannan ne matalauta sanin astrophysics na Sun: watakila haskaka subsoil model overestimated da adadin samar a cikin neutrino. Duk da haka, domin shekaru masu yawa, ko da bayan da hasken rana model sun inganta, da kasawa zauna. Lissafin kimiyya sun biya da hankali ga wani yiwuwar: matsalar da za a iya alaka da mu fahimta daga wadannan barbashi. Bisa ga ka'idar, sai rinjaye su ba su da nauyi. Amma wasu lissafin kimiyya sun bayar da hujjar cewa a gaskiya da barbashi da wani infinitesimal taro, da kuma wannan taro ya kasance dalilin rashin.

Uku-fuskanci barbashi

Bisa ga ka'idar neutrino oscillations, a cikin yanayi, akwai uku daban-daban na su. Idan wani barbashi yana da wani taro, da cewa kamar yadda motsa shi iya wuce daga daya irin zuwa wani. Iri uku - electrons, muons da tau - a cikin hulda da abu za a iya tuba zuwa ga m cajin barbashi (electron da muon tau leptons). "Oscillation" ne saboda jimla makanikai. neutrino irin shi ne ba m. Ya canza a kan lokaci. Neutrinos, wanda ya fara ta zama kamar wani e-mail, za a iya juya a cikin wani muon, sa'an nan a mayar da. Saboda haka, a barbashi, kafa a cikin ainihin rana, a kan hanyar zuwa Earth za a iya tuba a cikin lokaci-lokaci muon neutrinos da kuma mataimakin versa. Tun Davis injimin gano illa iya gane kawai electron-neutrinos, wanda zai iya haifar da wani nukiliya transmutation na chlorine a argon, ya zama kamar ma zai yiwu cewa bace neutrino juya a cikin wasu iri. (Sai dai itace cewa neutrinos oscillate ciki Sun, kuma ba a kan hanyar da Earth).

A Kanad gwaji

Iyakar hanyar gwada wannan ya haifar da wani injimin gano illa cewa aiki ga duk iri uku neutrinos. An fara daga 90s Arthur McDonald na Sarauniya ta University a Ontario, ya jagoranci 'yan wasan, wanda aka za'ayi a cikin wani mine a Sudbury, Ontario. Girkawar ƙunshi ton na nauyi ruwa, bayar da rance da Gwamnatin Canada. Tã ruwa ne rare, amma da sauƙi abin da ke faruwa nau'i na ruwa, cikinsa da hydrogen dauke daya proton aka maye gurbinsu da wa mutum isotope deuterium, wanda qunshi wani proton da wani neutron. Kanad gwamnatin stockpiled nauyi ruwa, m. K. Ana amfani da matsayin coolant a nukiliya reactor. All iri uku neutrinos iya hallaka deuterium ta samar da protons da neutrons, da neutrons sa'an nan kidaya. Gano rajista game da uku sau da lambar idan aka kwatanta da Davis - daidai da adadin da cewa mafi kyau annabta Sun model. Wannan ya nuna cewa electron-neutrinos iya oscillate a cikin wasu iri.

Japan gwaji

Kusan lokaci guda, Takaaki Kadzita daga Jami'ar Tokyo gudanar da wani gagarumin gwaji. A injimin gano illa saka a cikin shaft a Japan rubuta neutrinos zuwa ba daga cikin ciki na rãnã, kuma daga babba yanayi. A proton collisions na cosmic haskoki tare da yanayi na samuwa ne shawa wasu barbashi, ciki har da muon neutrinos. A nawa suka suna tuba zuwa hydrogen nuclei a muons. Gano Kadzity iya ganin barbashi zuwa kashi biyu. Wasu fadi daga sama, ya fito daga cikin yanayi, yayin da wasu suna motsi daga kasa. Yawan barbashi ya daban-daban, da cewa ya yi magana game da su daban-daban yanayi - sun kasance a daban-daban da maki a oscillatory sake zagayowar.

Juyin juya halin a Science

Yana da dukan m, kuma abin mamaki bane, amma me ya sa neutrino oscillations da taro jawo hankalin haka da yawa da hankali? Dalilin shi ne mai sauki. A misali model na na farko barbashi kimiyyar lissafi, ci gaba a kan na karshe shekaru hamsin na karni na ashirin, wanda daidai ya bayyana duk wasu lura a accelerators da sauran gwaje-gwajen, da neutrinos sun zama massless. A gano neutrino taro ya nuna cewa wani abu da ya bace. The Standard Model ba cikakke ba ne. M abubuwa tukuna da za a gano - tare da taimakon Manyan Hadron Collider ko wasu, ya ba tukuna halitta mai rumfa na'ura.