$\"kham_pha_khoa_hoc\"$ <\/p>\n

1. Kh\u00e1m ph\u00e1 ra \u201ch\u1ea1t c\u1ee7a ch\u00faa\u201d<\/strong><\/p>\n

Kh\u00e1m ph\u00e1 n\u1ed5i b\u1eadt nh\u1ea5t trong n\u0103m 2012 \u0111\u01b0\u1ee3c t\u1ea1p ch\u00ed Science b\u00ecnh ch\u1ecdn l\u00e0 vi\u1ec7c c\u00e1c nh\u00e0 khoa h\u1ecdc \u0111\u00e3 ch\u1ee9ng minh s\u1ef1 t\u1ed3n t\u1ea1i c\u1ee7a boson Higgs b\u1eb1ng th\u1ef1c nghi\u1ec7m. S\u1ef1 b\u00ed \u1ea9n c\u0169ng nh\u01b0 t\u1ea7m quan tr\u1ecdng c\u1ee7a h\u1ea1t Higgs \u0111\u00e3 khi\u1ebfn gi\u1edbi khoa h\u1ecdc \u0111\u1eb7t t\u00ean cho lo\u1ea1i h\u1ea1t n\u00e0y l\u00e0 \u201ch\u1ea1t c\u1ee7a Ch\u00faa\u201d.<\/p>\n

Nhi\u1ec1u n\u0103m qua, h\u00e0ng t\u1ec9 USD \u0111\u00e3 \u0111\u01b0\u1ee3c \u0111\u1ed5 ra v\u00e0 h\u00e0ng ch\u1ee5c ngh\u00ecn nh\u00e0 v\u1eadt l\u00fd \u0111\u00e3 lao v\u00e0o truy t\u00ecm h\u1ea1t Higgs. V\u00e0 trong n\u0103m 2012, Trung t\u00e2m Nghi\u00ean c\u1ee9u H\u1ea1t nh\u00e2n ch\u00e2u \u00c2u (CERN) \u0111\u00e3 ti\u1ebfn h\u00e0nh th\u00ed nghi\u1ec7m tr\u00ean m\u00e1y gia t\u1ed1c l\u1edbn, n\u01a1i c\u00e1c h\u1ea1t proton va v\u00e0o nhau v\u1edbi t\u1ed1c \u0111\u1ed9 g\u1ea7n b\u1eb1ng t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng, sinh ra nh\u1eefng m\u1ea3nh v\u1ee1 h\u1ea1 nguy\u00ean t\u1eed \u0111\u01b0\u1ee3c quan s\u00e1t k\u1ef9 c\u00e0ng nh\u1eb1m t\u00ecm d\u1ea5u hi\u1ec7u t\u1ed3n t\u1ea1i c\u1ee7a h\u1ea1t Higgs. Hai nh\u00f3m th\u00ed nghi\u1ec7m \u0111\u1ed9c l\u1eadp c\u1ee7a CERN \u0111\u00e3 t\u00ecm th\u1ea5y lo\u1ea1i h\u1ea1t m\u1edbi c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng x\u1ea5p x\u1ec9 125 Gigaelectronvolt (GeV – m\u1ed9t proton c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng kho\u1ea3ng 0,938 GeV). C\u1ea3 hai th\u00f4ng b\u00e1o k\u1ebft qu\u1ea3 c\u1ee7a h\u1ecd \u0111\u1ea1t m\u1ee9c \u201c5 sigma\u201d, ngh\u0129a l\u00e0 ch\u1ec9 c\u00f3 0,00006% c\u01a1 h\u1ed9i kh\u00e1m ph\u00e1 c\u1ee7a h\u1ecd sai l\u1ea1c.<\/p>\n

Ph\u00f2ng th\u00ed nghi\u1ec7m M\u00e1y gia t\u1ed1c Qu\u1ed1c gia Fermi (Fermilab) t\u1ea1i M\u1ef9 c\u0169ng th\u00f4ng b\u00e1o r\u1eb1ng h\u1ecd \u0111\u00e3 t\u00ecm ra nh\u1eefng b\u1eb1ng ch\u1ee9ng cu\u1ed1i c\u00f9ng v\u1ec1 s\u1ef1 t\u1ed3n t\u1ea1i c\u1ee7a h\u1ea1t Higgs sau khi ph\u00e2n t\u00edch d\u1eef li\u1ec7u t\u1eeb h\u00e0ng ngh\u00ecn t\u1ef7 v\u1ee5 va ch\u1ea1m h\u1ea1t trong Tevatron – m\u1ed9t m\u00e1y gia t\u1ed1c h\u1ea1t c\u00f3 c\u00f4ng su\u1ea5t l\u1edbn c\u1ee7a Fermilab.<\/p>\n

N\u1ebfu gi\u1edbi v\u1eadt l\u00fd c\u00f3 th\u1ec3 ch\u1ee9ng minh s\u1ef1 t\u1ed3n t\u1ea1i c\u1ee7a h\u1ea1t Higgs – m\u1ea3nh gh\u00e9p cu\u1ed1i c\u00f9ng trong m\u00f4 h\u00ecnh chu\u1ea9n c\u1ee7a v\u1eadt l\u00fd h\u1ea1t – th\u00ec ph\u00e1t hi\u1ec7n n\u00e0y s\u1ebd l\u00e0 m\u1ed9t trong nh\u1eefng th\u00e0nh t\u1ef1u khoa h\u1ecdc v\u0129 \u0111\u1ea1i nh\u1ea5t trong v\u00f2ng 100 n\u0103m. Ch\u1ee9ng minh \u0111\u01b0\u1ee3c s\u1ef1 t\u1ed3n t\u1ea1i c\u1ee7a h\u1ea1t Higgs, h\u1ecd c\u0169ng s\u1ebd x\u00f3a tan ho\u00e0i nghi v\u1ec1 s\u1ef1 t\u1ed3n t\u1ea1i c\u1ee7a v\u1eadt ch\u1ea5t t\u1ed1i, lo\u1ea1t v\u1eadt ch\u1ea5t c\u00f3 th\u1ec3 chi\u1ebfm t\u1edbi 75% kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a v\u0169 tr\u1ee5. Nh\u01b0ng h\u1ea1t Higgs kh\u00f4ng ch\u1ec9 c\u00f3 \u00fd ngh\u0129a \u0111\u1ed1i v\u1edbi v\u0169 tr\u1ee5 xa x\u00f4i, m\u00e0 c\u00f2n mang \u0111\u1ebfn nhi\u1ec1u l\u1ee3i \u00edch cho cu\u1ed9c s\u1ed1ng tr\u00ean \u0111\u1ecba c\u1ea7u. V\u1edbi h\u1ea1t Higgs, lo\u00e0i ng\u01b0\u1eddi s\u1ebd c\u00f3 th\u00eam m\u1ed9t ngu\u1ed3n n\u0103ng l\u01b0\u1ee3ng m\u1edbi v\u00e0 d\u1ed3i d\u00e0o. Ngo\u00e0i ra h\u1ea1t Higgs c\u00f2n c\u00f3 th\u1ec3 gi\u00fap con ng\u01b0\u1eddi t\u1ea1o n\u00ean nh\u1eefng th\u00e0nh t\u1ef1u c\u00f4ng ngh\u1ec7 \u0111\u1ed9t ph\u00e1 trong giao th\u00f4ng v\u00e0 vi\u1ec5n th\u00f4ng.<\/p>\n

2. Gi\u1ea3i m\u00e3 b\u1ed9 gene ng\u01b0\u1eddi c\u1ed5 x\u01b0a DenisovanS<\/strong><\/p>\n

C\u00e1c nh\u00e0 khoa h\u1ecdc thu\u1ed9c Vi\u1ec7n Nh\u00e2n ch\u1ee7ng h\u1ecdc ti\u1ebfn h\u00f3a Max Planck \u1edf \u0110\u1ee9c trong n\u0103m 2012 \u0111\u00e3 ho\u00e0n th\u00e0nh gi\u1ea3i m\u00e3 b\u1ed9 gene c\u1ee7a lo\u00e0i ng\u01b0\u1eddi c\u1ed5 x\u01b0a Denisovans, t\u1ed5 ti\u00ean c\u1ee7a ch\u00fang ta ng\u00e0y nay. C\u00e1c h\u00f3a th\u1ea1ch trong \u0111\u00f3 bao g\u1ed3m m\u1ed9t m\u1ea9u x\u01b0\u01a1ng ng\u00f3n tay, hai chi\u1ebfc r\u0103ng h\u00e0m c\u1ee7a m\u1ed9t d\u00f2ng d\u00f5i Denisovans \u0111\u00e3 tuy\u1ec7t ch\u1ee7ng, \u0111\u01b0\u1ee3c t\u00ecm th\u1ea5y t\u1ea1i hang Denisovans, mi\u1ec1n Nam Siberia v\u00e0o n\u0103m 2008. M\u1ea3nh x\u01b0\u01a1ng ng\u00f3n tay nh\u1ecf b\u00e9 cho ph\u00e9p c\u00e1c nh\u00e0 khoa h\u1ecdc gi\u1ea3i m\u00e3 to\u00e0n b\u1ed9 b\u1ed9 gene c\u1ee7a ng\u01b0\u1eddi c\u1ed5 Denisovans th\u00f4ng qua k\u1ef9 thu\u1eadt gi\u1ea3i m\u00e3 DNA. Ph\u01b0\u01a1ng ph\u00e1p n\u00e0y cho ph\u00e9p c\u00e1c nh\u00e0 nghi\u00ean c\u1ee9u t\u1ea1o ra b\u1ed9 gene m\u1ed9t c\u00e1ch chi ti\u1ebft v\u00e0 ho\u00e0n ch\u1ec9nh (30X), t\u01b0\u01a1ng t\u1ef1 b\u1ed9 gene c\u1ee7a ng\u01b0\u1eddi hi\u1ec7n \u0111\u1ea1i.<\/p>\n

C\u00e1c nghi\u00ean c\u1ee9u cho th\u1ea5y r\u1eb1ng h\u1ecd Denisovans c\u00f9ng chung s\u1ed1ng v\u1edbi ng\u01b0\u1eddi Neanderthals v\u00e0 lai gi\u1ed1ng v\u1edbi lo\u00e0i ng\u01b0\u1eddi ch\u00fang ta ng\u00e0y nay (t\u00ean khoa h\u1ecdc l\u00e0 Homo sapiens). Sau khi ng\u01b0\u1eddi Neanderthals v\u00e0 Denisovans tuy\u1ec7t ch\u1ee7ng, lo\u00e0i ng\u01b0\u1eddi ch\u00fang ta ng\u00e0y nay th\u1ed1ng tr\u1ecb Tr\u00e1i \u0111\u1ea5t. Nh\u1eefng ng\u01b0\u1eddi \u0111\u1ebfn t\u1eeb \u0110\u00f4ng Nam \u00c1 v\u00e0 Nam M\u1ef9 s\u1edf h\u1eefu nhi\u1ec1u gene c\u1ee7a ng\u01b0\u1eddi Neanderthals h\u01a1n ng\u01b0\u1eddi ch\u00e2u \u00c2u. \u0110i\u1ec1u n\u00e0y cho th\u1ea5y r\u1eb1ng t\u1ed5 ti\u00ean c\u1ed5 x\u01b0a c\u1ee7a h\u1ecd \u0111\u01b0\u1ee3c lai gi\u1ed1ng nhi\u1ec1u h\u01a1n v\u1edbi ng\u01b0\u1eddi Neanderthals.<\/p>\n

Xem ti\u1ebfp t\u1ea1i \u0111\u00e2y<\/em><\/strong><\/a><\/p>\n

\u0110\u1ee9c Ph\u01b0\u1eddng\u00a0 (t\u1ed5ng h\u1ee3p)<\/font><\/span><\/em><\/strong><\/p>\n

(Ngu\u1ed3n: Tia S\u00e1ng, 31\/12\/2012)<\/font><\/font><\/font><\/font><\/span><\/em><\/strong><\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"