AMP
Max results
Sort by Reverse order

Showing 10 of 80 results

Preliminary Observation of Parity Nonconservation in Atomic Thallium

Conti, R. ; Bucksbaum, P. ; Chu, S. ; et al.
Phys.Rev.Lett. 42 (1979) 343-346, 1979.
Inspire Record 136903 DOI 10.17182/hepdata.20786

Parity nonconservation is observed in the 6P122−7P122 transition in thallium. Absorption of circularly polarized 293-nm photons by 6P122 atoms in an E field results in polarization of the 7P122 state through interference of Stark E1 amplitudes with M1 and parity-nonconserving E1 amplitudes M and Ep. Detection of this polarization yields the circular dichroism δ=+(5.2±2.4)×10−3, which agrees in sign and magnitude with theoretical estimates based on the Weinberg-Salam model.

1 data table
Table 1

Used 99.999% pure thallium metal with natural isotopic abundances (29.5% Tl203, 70.5% Tl205). SIG(C+), SIG(C-) are the cross sections for absorption of 293-nm photons, with +,- helicity, respectively. Spin of the Tl nucleus is 1/2. Statistical errors only.


K0(L) K0(S) TRANSMISSION REGENERATION ON DEUTERONS AND NEUTRONS IN A MOMENTUM RANGE OF 10-GEV/C - 50-GEV/C

The BERLIN-BUDAPEST-DUBNA-PRAGUE-SERPUKHOV-SOFIYA-TBILISI collaboration Albrecht, K.-F. ; Birulev, V.K. ; Genchev, V. ; et al.
Nucl.Phys.B 158 (1979) 29-38, 1979.
Inspire Record 145094 DOI 10.17182/hepdata.34627

The energy dependence of the K L 0 -K S 0 transmission regeneration amplitudes on deuterons and neutrons in the momentum region 10–50 GeV/ c is determined. The moduli of the modified transmission amplitudes are momentum dependent. These dependences are fitted by the expression A j p − nj , where A j and n j ( j = d, n) are constants: A d =2.88 ±0.04 mb , n d =0.546±0.030, for deuterons , A n =1.97 ±0.14 mb , n n =0.530±0.019, for neutrons , The amplitude phases do not depend on the kaon momentum and are equal to ϕ d = (−130.9 ± 2.7)° ϕ n = (−132.3 ± 1.7)°. The mean value of the ratio of the total cross-section differences for K 0 and K 0 interactions with neutrons and protons is determined. The residues of the partial ω and ϱ amplitudes, which contribute to the kaon-nucleon interaction amplitudes, are also obtained.

2 data tables
Table 1

FORWARD CROSS SECTION, AMPLITUDE AND PHASE FOR K0 REGENERATION.

Table 2

(AK0 - K0) TOTAL CROSS SECTION DIFFERENCES.


Coherent $K$(s) Regeneration on Protons From 30-{GeV}/$c$ to 130-{GeV}/$c$

Bock, G.J. ; Aronson, S.H. ; Freudenreich, K. ; et al.
Phys.Rev.Lett. 42 (1979) 350, 1979.
Inspire Record 7461 DOI 10.17182/hepdata.20779

Precise measurements att=0 of the KLp→KSp amplitude (modulus and phase) were made. Over 50000 Kπ2 decays along with normalizing Kμ3 events were detected behind a 7.2-m-long liquid-hydrogen regenerator. The momentum dependence of the modulus and phase are presented, and the results are combined with those of other experiments to extract the relevant parameters of ω exchange.

2 data tables
Table 1

RESULTS USING ETA+- = 2.15E-3.

Table 2

RESULTS USING ETA+- = 2.27E-3.


PRODUCTION AND DECAY ANGULAR DISTRIBUTIONS OF THE Y* (1385) IN THE LINE REVERSED REACTIONS: pi+ p ---> K+ Y* (1385) AND K- p ---> pi- Y* (1385) AT 11.5-GeV/c

Cautis, C.V. ; Ballam, Joseph ; Bouchez, J. ; et al.
Nucl.Phys.B 156 (1979) 507-531, 1979.
Inspire Record 133382 DOI 10.17182/hepdata.34679

We have measured in a single experimental setup, the differential cross sections and decay angular distributions of the Y ∗ (1385) produced in the two line-reversed reactions: π + p → K + Y ∗+ (1385) (279 events/ω b ) and K − p → π − Y ∗+ (1385) (190 events/ωb) at 11.5 GeV/ c . The data have been derived from a triggered bubble-chamber experiment using the SLAC Hybrid Facility. We find the differential cross sections and Y ∗ polarizations for the two reactions to be in agreement with exchange-degeneracy predictions, if kinematic differences are taken into account. The Stodolsky-Sakurai and additive quark model predictions are in agreement with the main features of the decay angular distributions of the Y ∗ (1385), except for small violations at low momentum transfer, which can be associated with a finite helicity non-flip contribution in the forward direction.

6 data tables
Table 1

Axis error includes +- 10/10 contribution.

Table 2

THESE FINAL DIFFERENTIAL CROSS SECTIONS ARE INCLUDED IN THE RECORD OF J. BALLAM ET AL., PRL 41, 676 (1978).

Table 3

TRANSVERSITY AMPLITUDES FOR SIG(1385P13)+ PRODUCTION. THE IMAGINARY PARTS OF T(11) AND T(-1-1) WERE ARBITRARILY FIXED AT ZERO.

More…

Precise Coherent $K_S$ Regeneration Amplitudes for C, Al, Cu, {SN} and Pb Nuclei From 20-{GeV}/$c$ to 140-{GeV}/$c$ and Their Interpretation

Gsponer, A. ; Hoffnagle, J. ; Molzon, W.R. ; et al.
Phys.Rev.Lett. 42 (1979) 13, 1979.
Inspire Record 6964 DOI 10.17182/hepdata.20800

We have determined the coherent KS regeneration amplitudes on various nuclei, from 20 to 140 GeV/c, using a particularly systematics-free technique. Our results are well represented by |(f−f¯)k|=2.23A0.758p−0.614 mb. This p dependence corresponds to an effective "nuclear" intercept ``αω(0)''=0.386±0.009, whereas the elementary value is αω(0)=0.44±0.01. Comparisons are made with data below 25 GeV/c, and with optical-model predictions. The latter work only if "αω(0)" is postulated to hold for the elementary amplitudes.

1 data table
Table 1

No description provided.


Observation of Nonconservation of Parity in Atomic Transitions

Barkov, L.M. ; Zolotorev, M.S. ;
JETP Lett. 27 (1978) 357, 1978.
Inspire Record 129724 DOI 10.17182/hepdata.39779

None

1 data table
Table 1

OPTICAL ROTATION ANGLE DUE TO PARITY NONCONSERVING INTERACTIONS.


A Study of Noncharge Exchange anti-K0 pi- Production in the Reaction K- p --> anti-K0 pi- p at 4.2-GeV/c

The AMSTERDAM-CERN-NIJMEGEN-OXFORD collaboration Engelen, J.J ; Holwerda, M.J. ; Kittel, E.W. ; et al.
Nucl.Phys.B 134 (1978) 14-30, 1978.
Inspire Record 134670 DOI 10.17182/hepdata.35138

The K π − system produced in the reaction K p → K 0 π − p at 4.2 GeV/ c is studied using high-statistics bubble-chamber data. The spin-parity structure is analysed as a function of the K 0 π − mass up to 1.52 GeV. Production of K ∗ (890) and K ∗ (1420) is observed in helicity-0 and helicity-1 states. Contributions of natural and unnatural parity exchange are present. Considerable S-wave production is observed over the whole mass region considered. We also study the t ′ dependence of the K ∗ (890) and K ∗ (1420) amplitudes. A comparison of our results on K ∗ (890) production with the results of an analysis of charge-exchange K ∗ (890) production, allows the separation of I = 0 and I = 1 exchange amplitudes. Some qualitative remarks are made concerning K ∗ (1420) production.

2 data tables
Table 1

No description provided.

Table 2

PARTIAL WAVE ANALYSIS ASSUMING SPIN-COHERENCE TO OBTAIN SPIN-PARITY STRUCTURE AND T DEPENDENCE OF P-WAVE AND D-WAVE AMPLITUDES.


Measurement of the Real Part of the Forward Amplitude in K- n and K+ n Elastic Scattering at 10-GeV/c and a New K+- n Dispersion Relation

Baillon, P. ; Declais, Y. ; Ferro-Luzzi, M. ; et al.
Nucl.Phys.B 134 (1978) 31-48, 1978.
Inspire Record 122470 DOI 10.17182/hepdata.35130

The differential cross section in the very forward direction has been measured for K − and K + scattering (break-up and coherent) on a deuterium target at an incident momentum of 10 GeV/ c . From these measurements and using a model for the scattering and re-scattering effects in deuterium, we have exploited the Coulomb-nuclear interference to deduce the real part of the K ± n scattering amplitude at a momentum transfer t = 0. The measurements are the first ever obtained for the K + n reaction and the first at this energy for the K − n reaction. A comparison has been made between our results and those predicted from dispersion relations. A new dispersion-relation fit including all the existing K ± n values at different energies has been performed.

2 data tables
Table 1

SUM OF COHERENT AND BREAK-UP SCATTERING ON DEUTERIUM.

Table 2

FROM FIT TO D(SIG)/DT OVER -T=0.0018 TO 0.074 GEV**2 ALLOWING FOR COULOMB SCATTERING, DOUBLE SCATTERING, INTERFERENCES AND FERMI MOTION. CORRELATION BETWEEN SLOPE AND RE(AMP)/IM(AMP) IS REFLECTED IN THE GIVEN SYSTEMATIC E RRORS.


Nonstrange Vector Meson Production in K- p Interactions at 4.2-GeV/c

The Amsterdam-CERN-Nijmegen-Oxford collaboration Losty, M.J. ; Holmgren, S.-O. ; Aguilar-Benitez, M. ; et al.
Nucl.Phys.B 133 (1978) 38, 1978.
Inspire Record 121759 DOI 10.17182/hepdata.8294

The vector meson production, hypercharge exchange reactions K − p → ( φ , ω , ϱ ) Λ and ( φ , ϱ ) Σ 0 are studied at 4.2 GeV/ c incident momentum. The data come from a high statistics bubble chamber experiment with a sensitivity of ∼ 120 events/μb. Total and differential cross sections are presented. The vector meson density matrix elements and hyperon polarization are investigated as functions of momentum transfer. Amplitude analyses are performed for all five reactions. The results are compared with duality and quark model predictions, as well as used to test current ideas in two-body phenomenology.

38 data tables
Table 1

ERRORS INCLUDE THE 5 PCT MODEL ERROR BUT NOT THEORETICAL RESONANCE PARAMETRIZATION ERRORS.

Table 2

No description provided.

Table 3

No description provided.

More…

Neutral Kaon Transmission Regeneration on Deuterons and Neutrons in Kaon Momentum Region of 10-GeV/c to 50-GeV/c

The Berlin-Budapest-Dubna-Prague-Serpukhov-Sofiya-Tbilisi collaboration Albrecht, K.F. ; Birulev, V.K. ; Vesztergombi, G. ; et al.
Sov.J.Nucl.Phys. 27 (1978) 199, 1978.
Inspire Record 122158 DOI 10.17182/hepdata.19037

None

4 data tables
Table 1

THE AVERAGE PHASE IS -130.9 +- 2.7 DEG (NO EXPLICIT MOMENTUM DEPENDENCE). USING ABS(ETA+-) = 2.3*10**-3.

Table 2

REGENERATION AMPLITUDE ASSUMING MOMENTUM INDEPENDENT CONSTANT PHASE.

Table 3

CROSS SECTION DIFFERENCES ASSUMING MOMENTUM INDEPENDENT CONSTANT PHASE.

More…