Shvinger effekti

Shvinger effekti taxmin qilingan fizik hodisa bo'lib, bunda modda kuchli elektr maydon tomonidan yaratilgan. U, shuningdek, Sauter-Schwinger effekti, Shvinger mexanizmi yoki Shvinger juft ishlab chiqarish deb ataladi. Bu kvant elektrodinamikasining (KED) bashorati bo'lib, unda elektr maydonining mavjudligida elektron - pozitron juftlari o'z-o'zidan paydo bo'ladi va shu bilan elektr maydonining parchalanishiga olib keladi. Effekt dastlab 1931-yilda Fritz Sauter tomonidan taklif qilingan^[1] va keyingi muhim ishni 1936-yilda Verner Heisenberg va Hans Geynrix Eyler amalga oshirgan^[2], ammo 1951-yilgacha Julian Shvinger to'liq nazariy tavsif bergan edi.^[3]

Shvinger effektini elektr maydon mavjudligida vakuumli parchalanish deb hisoblash mumkin. Vakuumli parchalanish tushunchasi biror narsa yo'qdan yaratilganligini ko'rsatsa ham, fizik saqlanish qonunlariga rioya qilinadi. Buni tushunish uchun elektronlar va pozitronlar bir-birining antizarralari bo'lib, qarama-qarshi elektr zaryadidan tashqari bir xil xususiyatlarga ega.

Energiyani tejash uchun elektron-pozitron juftligi hosil bo'lganda elektr maydoni energiyani yo'qotadi. Unga teng miqdorda 2 $m_{\text{e}}$ c², bu yerda $m_{\text{e}}$ elektronning tinchlikdagi massasi va $c$ yorug'lik tezligidir. Elektr zaryadi saqlanib qoladi, chunki elektron-pozitron juftligi zaryad neytraldir. Chiziqli va burchak impulslari saqlanib qoladi, chunki har bir juftlikda elektron va pozitron qarama-qarshi tezlik va spinlar bilan yaratilgan. Darhaqiqat, elektron va pozitron tinch (yaqin) holatda yaratilishi va keyinchalik elektr maydoni tomonidan bir-biridan tezlashishi kutiladi.^[4]

Matematik tavsifi[tahrir | manbasini tahrirlash]

Bu tavsif birinchi bo'lib Shvinger tomonidan hisoblab chiqilgan va yetakchi (bir-loop) tartibida teng bo'lib, u quyidagicha ifodalanadi:

\Gamma ={\frac {(eE)^{2}}{4\pi ^{3}c\hbar ^{2}}}\sum _{n=1}^{\infty }{\frac {1}{n^{2}}}\mathrm {e} ^{-{\frac {\pi m^{2}c^{3}n}{eE\hbar }}}

bu yerda $m$ elektronning massasi, $e$ elementar zaryad hisoblanadi va $E$ elektr maydon kuchidir. Ushbu formulani Teylor seriyasida kengaytirib bo'lmaydi $e^{2}$ , bu ta'sirning noxush xususiyatini ko'rsatadi. Feynman diagrammalari nuqtai nazaridan, Shvinger juftligini ishlab chiqarish tezligini quyida ko'rsatilgan cheksiz diagramma to'plamini yig'ish orqali olish mumkin, ularda bitta elektron halqa va har qanday miqdordagi tashqi foton oyoqlari mavjud, ularning har biri nol energiyaga ega.

The Schwinger effect has never been observed due to the extremely strong electric-field strengths required. Pair production takes place exponentially slowly when the electric field strength is much below the Schwinger limit, corresponding to approximately 7018100000000000000♠10¹⁸ V/m. With current and planned laser facilities, this is an unfeasibly strong electric-field strength, so various mechanisms have been proposed to speed up the process and thereby reduce the electric-field strength required for its observation.

Juft ishlab chiqarish tezligi vaqtga bog'liq bo'lgan elektr maydonlarida sezilarli darajada oshishi mumkin^[5]^[6]^[7] va shuning uchun Ekstremal yorug'lik infratuzilmasi kabi yuqori intensiv lazer tajribalari tomonidan olib borilmoqda.^[8] Yana bir imkoniyat - kuchli elektr maydonini ishlab chiqaradigan yuqori zaryadlangan yadroni kiritish.^[9]

Elektromagnit ikkilikka ko'ra, magnit maydondagi xuddi shu mexanizm magnit monopollarni hosil qilishi kerak, agar ular mavjud bo'lsa. Katta adron kollayderi yordamida olib borilgan qidiruv monopollarni aniqlay olmadi va tahlil monopol massasining pastki chegarasi 7001750000000000000♠75 GeV/c² ni tashkil etdi.7001750000000000000♠75 GeV/c² 95% ishonch darajasida.^[10]

Manbalar[tahrir | manbasini tahrirlash]

↑ Sauter, Fritz (1931). „Über das Verhalten eines Elektrons im homogenen elektrischen Feld nach der relativistischen Theorie Diracs“. Zeitschrift für Physik (nemischa). 69-jild, № 11–12. Springer Science and Business Media LLC. 742–764-bet. doi:10.1007/bf01339461. ISSN 1434-6001.
↑ Heisenberg, W.; Euler, H. (1936). „Folgerungen aus der Diracschen Theorie des Positrons“. Zeitschrift für Physik (nemischa). 98-jild, № 11–12. Springer Science and Business Media LLC. 714–732-bet. arXiv:physics/0605038. doi:10.1007/bf01343663. ISSN 1434-6001.
↑ Schwinger, Julian (1951-06-01). „On Gauge Invariance and Vacuum Polarization“. Physical Review. 82-jild, № 5. American Physical Society (APS). 664–679-bet. doi:10.1103/physrev.82.664. ISSN 0031-899X.
↑ A.I. Nikishov (1970). „Pair Production by a Constant External Field“. Journal of Experimental and Theoretical Physics. 30-jild. 660-bet.
↑ Brezin, E.; Itzykson, C. (1970-10-01). „Pair Production in Vacuum by an Alternating Field“. Physical Review D. 2-jild, № 7. American Physical Society (APS). 1191–1199-bet. doi:10.1103/physrevd.2.1191. ISSN 0556-2821.
↑ Ringwald, A. (2001). „Pair production from vacuum at the focus of an X-ray free electron laser“. Physics Letters B. 510-jild, № 1–4. Elsevier BV. 107–116-bet. doi:10.1016/s0370-2693(01)00496-8. ISSN 0370-2693.
↑ Popov, V. S. (2001). „Schwinger mechanism of electron–positron pair production by the field of optical and X-ray lasers in vacuum“. Journal of Experimental and Theoretical Physics Letters. 74-jild, № 3. Pleiades Publishing Ltd. 133–138-bet. doi:10.1134/1.1410216. ISSN 0021-3640.
↑ I. C. E. Turcu; et al. (2016). „High field physics and QED experiments at ELI-NP“ (PDF). Romanian Reports in Physics. 68-jild. S145-S231-bet. 2022-07-07da asl nusxadan (PDF) arxivlandi. Qaraldi: 2022-08-06.
↑ Müller, C.; Voitkiv, A. B.; Grün, N. (2003-06-24). „Differential rates for multiphoton pair production by an ultrarelativistic nucleus colliding with an intense laser beam“. Physical Review A. 67-jild, № 6. American Physical Society (APS). 063407-bet. Bibcode:2003PhRvA..67f3407M. doi:10.1103/physreva.67.063407. ISSN 1050-2947.
↑ Acharya, B.; Alexandre, J.; Benes, P.; Bergmann, B.; Bertolucci, S.; et al. (2022-02-02). „Search for magnetic monopoles produced via the Schwinger mechanism“. Nature. 602-jild, № 7895. Springer Science and Business Media LLC. 63–67-bet. doi:10.1038/s41586-021-04298-1. ISSN 0028-0836.

[1] Sauter, Fritz (1931). „Über das Verhalten eines Elektrons im homogenen elektrischen Feld nach der relativistischen Theorie Diracs“. Zeitschrift für Physik (nemischa). 69-jild, № 11–12. Springer Science and Business Media LLC. 742–764-bet. doi:10.1007/bf01339461. ISSN 1434-6001.

[2] Heisenberg, W.; Euler, H. (1936). „Folgerungen aus der Diracschen Theorie des Positrons“. Zeitschrift für Physik (nemischa). 98-jild, № 11–12. Springer Science and Business Media LLC. 714–732-bet. arXiv:physics/0605038. doi:10.1007/bf01343663. ISSN 1434-6001.

[Schwinger-3] Schwinger, Julian (1951-06-01). „On Gauge Invariance and Vacuum Polarization“. Physical Review. 82-jild, № 5. American Physical Society (APS). 664–679-bet. doi:10.1103/physrev.82.664. ISSN 0031-899X.

[4] A.I. Nikishov (1970). „Pair Production by a Constant External Field“. Journal of Experimental and Theoretical Physics. 30-jild. 660-bet.

[5] Brezin, E.; Itzykson, C. (1970-10-01). „Pair Production in Vacuum by an Alternating Field“. Physical Review D. 2-jild, № 7. American Physical Society (APS). 1191–1199-bet. doi:10.1103/physrevd.2.1191. ISSN 0556-2821.

[6] Ringwald, A. (2001). „Pair production from vacuum at the focus of an X-ray free electron laser“. Physics Letters B. 510-jild, № 1–4. Elsevier BV. 107–116-bet. doi:10.1016/s0370-2693(01)00496-8. ISSN 0370-2693.

[7] Popov, V. S. (2001). „Schwinger mechanism of electron–positron pair production by the field of optical and X-ray lasers in vacuum“. Journal of Experimental and Theoretical Physics Letters. 74-jild, № 3. Pleiades Publishing Ltd. 133–138-bet. doi:10.1134/1.1410216. ISSN 0021-3640.

[8] I. C. E. Turcu; et al. (2016). „High field physics and QED experiments at ELI-NP“ (PDF). Romanian Reports in Physics. 68-jild. S145-S231-bet. 2022-07-07da asl nusxadan (PDF) arxivlandi. Qaraldi: 2022-08-06.

[9] Müller, C.; Voitkiv, A. B.; Grün, N. (2003-06-24). „Differential rates for multiphoton pair production by an ultrarelativistic nucleus colliding with an intense laser beam“. Physical Review A. 67-jild, № 6. American Physical Society (APS). 063407-bet. Bibcode:2003PhRvA..67f3407M. doi:10.1103/physreva.67.063407. ISSN 1050-2947.

[10] Acharya, B.; Alexandre, J.; Benes, P.; Bergmann, B.; Bertolucci, S.; et al. (2022-02-02). „Search for magnetic monopoles produced via the Schwinger mechanism“. Nature. 602-jild, № 7895. Springer Science and Business Media LLC. 63–67-bet. doi:10.1038/s41586-021-04298-1. ISSN 0028-0836.

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