Зависимость среднего поперечного импульса лидирующих

реклама
Çàâèñèìîñòü ñðåäíåãî ïîïåðå÷íîãî èìïóëüñà ëèäèðóþùèõ àäðîíîâ
îò êèíåìàòè÷åñêèõ ïåðåìåííûõ ïîëóèíêëþçèâíîé ðåàêöèè ðîæäåíèÿ
àäðîíîâ â ãëóáîêî íåóïðóãîì ðàññåÿíèè ïîçèòðîíîâ íà íóêëîíàõ
À. À. Æãóí, Ñ. È. Ìàíàåíêîâ
Àííîòàöèÿ
Ñ ïîìîùüþ ñïåêòðîìåòðà HERMES íà óñêîðèòåëå HERA (DESY, Ãåðìàíèÿ) èçìåðÿëîñü ðîæäåíèå ëèäèðóþùèõ àäðîíîâ â ãëóáîêî íåóïðóãîì ðàññåÿíèè ïîçèòðîíîâ íà íóêëîíàõ. Áûëè ïîëó÷åíû çàâèñèìîñòè ñðåäíåãî ïîïåðå÷íîãî èìïóëüñà àäðîíîâ îò z, õB è W 2. Áûëî íàéäåíî, ÷òî ïðè
z > 0.6 ñðåäíèé ïîïåðå÷íûé èìïóëüñ ëèäèðóþùèõ àäðîíîâ çàâèñèò îò çàðÿäà àäðîíà.
Abstract
Semi-inclusive production of the leading positive and negative pions (hadrons) and K 0S has been
studied using the HERMES spectrometer. Dependences of the mean transverse momentum P⊥
of the produced hadrons on z, XB and W 2 have been analyzed. It has been found that at z > 0.6 P⊥ starts
to be sensitive to the charge of the produced hadron.
Ïðåïðèíò ¹2448, 6.11.2001 ã.
E-mail: ant@rec03.pnpi.spb.ru
Manifest Calculation and the Finiteness of the Superstring Feynman Diagrams
G. S. Danilov
Àííîòàöèÿ
Ìíîãîïåòëåâûå àìïëèòóäû çàìêíóòîé, îðèåíòèðîâàííîé ñóïåðñòðóíû ïðåäñòàâëåíû êîíå÷íîìåðíûìè èíòåãðàëàìè îò ÿâíûõ ôóíêöèé, âû÷èñëåííûõ ÷åðåç ïàðàìåòðû ñóïåðãðóïïû Øîòêè è
êîîðäèíàòû âåðøèí âçàèìîäåéñòâèÿ íà ñóïåðìíîãîîáðàçèè. Îáëàñòü èíòåãðèðîâàíèÿ ïîëíîñòüþ îïðåäåëÿåòñÿ ëîêàëüíûìè ñèììåòðèÿìè àìïëèòóäû è óíèòàðíîñòüþ. Êðîìå SL(2) ñèììåòðèè, ãðóïïà âêëþ÷àåò ñóïåðãðóïïó Øîòêè è òå èçîìîðôèçìû ìåæäó íàáîðàìè áàçèñíûõ ïðåîáðàçîâàíèé, êîòîðûå íå ìåíÿþò ìàòðèöó ïåðèîäîâ. Ìíîãîïåòëåâûå àìïëèòóäû ïîëó÷åíû ñâîáîäíûìè îò ðàñõîäèìîñòåé. Çàíóëåíèå 0-,1-,2- è 3-òî÷å÷íûõ àìïëèòóä óñòàíîâëåíî. Ïîêàçàíî
èñ÷åçíîâåíèå àìïëèòóä èçëó÷åíèÿ ïðîäîëüíîãî êàëèáðîâî÷íîãî áîçîíà.
Abstract
The multi-loop amplitudes for the closed, oriented superstring are represented by finite dimensional
integrals of explicit functions calculated in terms of the super-Schottky group parameters and interaction
vertex coordinates on the supermanifold. The integration region is given by the group of the local
symmetries of the amplitude and the unitarity. It is shown that, besides the SL(2) group, super-Schottky
group and modular one, the total group of the local symmetries includes an isomorphism between sets
of the forming group transformations, the period matrix to be the same. The calculation of the integrals
over singular configurations is developed preserving all the local symmetries of the amplitude,
the amplitudes being free from divergences. The nullification of the 0-, 1-, 2- and 3-point amplitudes
of massless states is verified. Vanishing the amplitudes for a longitudinal gauge boson is argued.
Ïðåïðèíò ¹2449, 13.11.2001 ã., àíãë. òåêñò.
E-mail: danilov@thd.pnpi.spb.ru
ïðåïðèíòû 11.2001 ã.
Íîâûå èíòåðôåðåíöèîííûå ýôôåêòû â îïûòàõ ïî õðàíåíèþ
óëüòðàõîëîäíûõ íåéòðîíîâ è çàïðåò êâàíòîâûõ ñâîéñòâ ÷àñòèö
Ã. Ì. Àìàëüñêèé
Àííîòàöèÿ
Ñäåëàíà îöåíêà âêëàäà âçàèìîäåéñòâèÿ ñ ôîíîíàìè â âåðîÿòíîñòü íåáîëüøîãî óâåëè÷åíèÿ
êèíåòè÷åñêîé ýíåðãèè óëüòðàõîëîäíûõ íåéòðîíîâ ïðè îòðàæåíèè îò ñòåíîê ëîâóøêè, îáíàðóæåííîãî â îïûòàõ ïî èõ õðàíåíèþ â ëîâóøêå. Ïîëó÷åííàÿ âåëè÷èíà â ~ 1010 ðàç ìåíüøå íàáëþäàåìîé â îïûòàõ ñ ÓÕÍ. Ïîêàçàíî, ÷òî ê ýòîé îøèáêå â ïðåäñêàçàíèÿõ ïðèâîäèò ãèïîòåçà î êâàíòîâûõ ñâîéñòâàõ ÷àñòèö, è îáúÿñíåíà âîçìîæíîñòü èñïðàâëåíèÿ òåîðèè áåç èçìåíåíèÿ êâàíòîâîãî
àïïàðàòà. Äîêàçàíà îøèáî÷íîñòü çàïðåòîâ àëüòåðíàòèâíîé èíòåðïðåòàöèè àïïàðàòà è ñôîðìóëèðîâàíà íåïðîòèâîðå÷èâàÿ ñòàòèñòè÷åñêàÿ òåîðèÿ íåðàçëè÷èìûõ âîçìîæíûõ ñîáûòèé, ãäå ïðè÷èíîé âñåõ êâàíòîâûõ ýôôåêòîâ ÿâëÿåòñÿ îãðàíè÷åííàÿ òî÷íîñòü ïðèáîðîâ. Âûÿñíåí íåòðèâèàëüíûé ìåõàíèçì äåïîëÿðèçàöèè è ïîãëîùåíèÿ ÓÕÍ: âûíóæäåííûé ðàñïàä âîçíèêàþùåé èç-çà
âçàèìîäåéñòâèÿ ñ ôîíîíàìè íåðàâíîâåñíîé êîìïîíåíòû ñîñòîÿíèÿ ÓÕÍ. Ïîëó÷åíû êîëè÷åñòâåííûå ïðåäñêàçàíèÿ, êîòîðûå íå ñîäåðæàò íåèçâåñòíûõ ïàðàìåòðîâ è îáúÿñíÿþò âñå èçâåñòíûå
ðåçóëüòàòû îïûòîâ ñ ÓÕÍ.
Abstract
There is estimated a contribution of interaction with phonons in the probability of small increasing
ultracold neutrons energe at their reflection of trap's walls, discovered in experiments of storage of UCN
in trap. Proved theoretical value is smaller in 1010 times then it is observed in experiments with UCN.
It is proved, that this mistake in predictions is caused by hypothesis of quantum properties of particles,
and possibility to correct theory without modification of quantum mechanical apparatus is shown. There
is proved that interdiction of alternative interpretation of apparatus is fault and consistent statistical
theory of indistinguishable possible events is formulated, where all quantum effects are caused by
restricted precision of instruments. Complex mechanism of depolarisation and losses of UCN is
discovered: disintegration of caused by interaction with phonons inequilibrate component of UCN state.
Obtained on this way without unknown parameters quantative predictions agree with all known UCN
experimental results.
Ïðåïðèíò ¹2450, 23.11.2001 ã.
E-mail: amalsky@hep486.pnpi.spb.ru
ïðåïðèíòû 11.2001 ã.
Laue Diffraction Method of a Neutron EDM Search.
Experimental Test of the Method
V. V. Fedorov, E. G. Lapin,
S. Yu. Semenikhin, V. V. Voronin
Àííîòàöèÿ
 ðàáîòå îïèñàí íîâûé ìåòîä ïîèñêà ýëåêòðè÷åñêîãî äèïîëüíîãî ìîìåíòà (ÝÄÌ) íåéòðîíà
ñ èñïîëüçîâàíèåì äèôðàêöèè ïî Ëàóý â íåöåíòðîñèììåòðè÷íîì êðèñòàëëå. Ìåòîä îñíîâàí
íà ýôôåêòå äåïîëÿðèçàöèè ïðîäèôðàãèðîâàâøèõ íåéòðîíîâ êàê â ïðÿìîì, òàê è â îòðàæåííîì
ïó÷êàõ, à òàêæå íà ñóùåñòâåííîì óâåëè÷åíèè âðåìåíè ïðîõîæäåíèÿ íåéòðîíà ÷åðåç êðèñòàëë
ïðè óãëàõ Áðýããà θÂ, áëèçêèõ ê ïðÿìîìó. Ýêñïåðèìåíòàëüíî ïîêàçàíî, ÷òî äëÿ êðèñòàëëà α-êâàðöà ïðè θ = 87° âåëè÷èíà Åτ, îïðåäåëÿþùàÿ ÷óâñòâèòåëüíîñòü ìåòîäà ê ÝÄÌ íåéòðîíà, äîñòèãàåò çíà÷åíèÿ ≈ 2⋅105  ñ/ñì, ÷òî ñðàâíèìî ñ íàèáîëåå òî÷íûì íà íûíåøíèé ìîìåíò ìàãíèòîðåçîíàíñíûì ìåòîäîì, èñïîëüçóþùèì óëüòðàõîëîäíûå íåéòðîíû. Ñ ó÷åòîì âûñîêîé ñâåòîñèëû ìåòîäà åãî ÷óâñòâèòåëüíîñòü ìîæåò äîñòèãàòü ~ 10-25 å ⋅ñì/äåíü äëÿ ðåàëüíî ñóùåñòâóþùèõ êðèñòàëëîâ α-êâàðöà.
Abstract
New method of a search for a neutron electric dipole moment (EDM) using Laue diffraction
in the noncentrosymmetric crystal is proposed. The method is based on the effect of depolarization
of the diffracted neutron beams (direct and reflected) passed through such crystal and on the essential
increasing the neutron passage time through the crystal for the Bragg angles θ close to 90°. Description
of the effect and set-up is given. It is shown experimentally that for α-quartz crystal and θ = 87°
the value of Åτ determining the sensitivity of the method can be ≈ 2⋅105 V s/cm, what is comparable with
the magnetic resonance method using ultracold neutrons (UCN-method). Taking into account
the luminosity of the proposed method, the value of its sensitivity may reach ~ 10-25 e⋅cm per day for
really existing α-quartz crystal.
Ïðåïðèíò ¹2451, 22.11.2001 ã., àíãë. òåêñò.
E-mail: vfedorov@hep486.pnpi.spb.ru
ïðåïðèíòû 11.2001 ã.
!
Èçìåðåíèå ïîëíûõ è äèôôåðåíöèàëüíûõ ñå÷åíèé ðåàêöèè π –p → ηn
π-äåòåêòîðà ïîëíîãî ïîãëîùåíèÿ «Crystal Ball»
ñ ïîìîùüþ 4π
Í. Ã. Êîçëåíêî, Â. Â. Àáàåâ, Â. Ñ. Áåêðåíåâ, Ñ. Ï. Êðóãëîâ,
À. À. Êóëáàðäèñ, È. Â. Ëîïàòèí, À. Á. Ñòàðîñòèí, Á. Äðàïåð,
Ñ. Õàéäåí, Ä. Õàääëåñòîí, Ä. Ýéçåíõàóåð, Ê. Ðîáèíñîí,
Ì. Ñàäëåð, Ê. Àëãîâåð, Ð. Êàäìàí, X. Ñïèíêà,
Ä. Ð. Êîìôîðò, Ê. Êðýéã, À. Ô. Ðàìèðåç, Ò. Êàñèÿ,
Ì. Êëàóñ, À. Ìàðóñèê, Ñ. Ìàêäîíàëä, Á. Ì. Ê. Íåôêåíñ,
Í. Ôàèñàíãèòèñàêóë, Ñ. Ïðàõîâ, Ä. Ïðàéñ, Â. Á. Òèïïåíñ,
Ä. Ïåòåðñîí, Â. Ä. Áðèñêî, À. Øàôè, È. Ñòàðàêîâñêèé,
Ã. Ñòóäåíìàåð, Ä. Ì. Ìàíëåé, Ä. Îëìñòåä, Ä. Ïèçëè,
Í. Êíåõò, Ä. Ëîëîñ, 3. Ïàïàíäðåó, È. Ñóïåê, È. Ñëàóñ, À. Ãèáñîí,
Ä. Ãðîñíèê, Ä. Êîòêå, Ð. Ìàíâåéëåð, Ø. Ñòàíèñëàóñ
(Êîëëàáîðàöèÿ Crystal Ball)
Àííîòàöèÿ
Ïðåäñòàâëåíû ïåðâûå ðåçóëüòàòû èçìåðåíèÿ ïîëíûõ è äèôôåðåíöèàëüíûõ ñå÷åíèé ðåàêöèè
π p → η n, ïîëó÷åííûå â 1998 ã. êîëëàáîðàöèåé «Crystal Ball». Íîâûå ýêñïåðèìåíòàëüíûå ðåçóëüòàòû ïî ïîëíûì ñå÷åíèÿì ñðàâíèâàþòñÿ ñ ïðåäñêàçàíèÿìè Ê-ìàòðè÷íîé ìîäåëè ïèîí-íóêëîííîãî ðàññåÿíèÿ. Ïðåäñòàâëåíû äèôôåðåíöèàëüíûå ñå÷åíèÿ äëÿ èìïóëüñîâ 705, 720,
750 ÌýÂ/ñ. Óãëîâîå ðàñïðåäåëåíèå îêîëî ïîðîãà ðåàêöèè (705 ÌýÂ/ñ) îïðåäåëÿåòñÿ âêëàäîì
S-âîëíû, òîãäà êàê, íà÷èíàÿ ñ èìïóëüñà 720 ÌýÂ/ñ, â óãëîâûõ ðàñïðåäåëåíèÿõ ïðîÿâëÿåòñÿ âêëàä
Ð-âîëíû.
–
Abstract
Data on the total and differential cross sections of the reaction π –p → η n, obtained in 1998
by the Crystal Ball Collaboration, are presented. These new experimental results for total cross sections
compared to the predictions of the model of pion-nucleon scattering in the K-matrix approach. Differential
cross sections for momenta 705, 720, 750 MeV/c are presented. It is possible to see that the angular
distribution at momenta near the threshold (705 MeV/c) is consistent with the S-wave dominance.
From the momentum of 720 MeV/c, the P-wave contribution can be found.
Ïðåïðèíò ¹2452, 26.11.2001 ã.
E-mail: kozlenko@pnpi.spb.ru
ïðåïðèíòû 11.2001 ã.
"
Granular Superconductors and Sandpile Model
with Intrinsic Spatial Randomness
S. L. Ginzburg, N. E. Savitskaya
Àííîòàöèÿ
 ðàáîòå ïðåäñòàâëåíà ïðèíöèïèàëüíî íîâàÿ ìîäåëü äëÿ èçó÷åíèÿ ñàìîîðãàíèçîâàííîé êðèòè÷íîñòè, â îñíîâå êîòîðîé ëåæèò ðåàëüíàÿ ôèçè÷åñêàÿ ñèñòåìà – ãðàíóëèðîâàííûé ñâåðõïðîâîäíèê. Ïîêàçàíî, ÷òî ïðåäñòàâëåííàÿ ìîäåëü äåìîíñòðèðóåò ñàìîîðãàíèçîâàííîå ïîâåäåíèå
äàæå â òåõ óñëîâèÿõ, â êîòîðûõ â ðàíåå ïðåäëîæåííûõ ìîäåëÿõ ñàìîîðãàíèçàöèè íå íàáëþäàëîñü.
Abstract
We present a new model for investigation of self-organized criticality, applicable to a real physical
system, a granular superconductor. The model demonstrates self-organized behaviour even in such
circumstances when other models do not.
Ïðåïðèíò ¹2453, 30.11.2001 ã., àíãë. òåêñò.
E-mail: –
ïðåïðèíòû 11.2001 ã.
#
Скачать