共查询到20条相似文献,搜索用时 31 毫秒
1.
J. Fischer 《Zeitschrift fur Physik C Particles and Fields》1987,36(2):273-281
Predictions based on axiomatic field theory are obtained from the assumption that the difference between thepp and thep \(\bar p\) elastic scattering observed at the CERN ISR is caused by an “odderon-like” term in the scattering amplitude. A wide class of amplitudes violating the Pomeranchuk relation is considered. Contrary to common opinion, severe restrictions on the high-energy behaviour of the phase of the crossing-odd amplitude are shown to follow for the whole class. Less pronounced but still visible consequences follow for the phases of thepp andp \(\bar p\) amplitudes separately. We derive the corresponding high-energy bounds and correlations using the general frame of analyticity, crossing symmetry and unitarity. As a special case, the maximal odderon amplitude is discussed. 相似文献
2.
We attempt to impose elastic unitarity on the forward π-π scattering using the Veneziano Amplitude together with a crossing symmetric subtraction term as an input. TheN/D method is used and thep, ? mesons are interpreted as CDD poles. The self consistency requirement led to the evalutation of the low energy parameters and theS andP-wave phase shifts. The values of the scattering lengths obtained area 0 0 =0.084m π ?1 ,a 2 0 =?0.024m π ?1 ,a 1 1 =0.047m π ?3 . 相似文献
3.
T. F. Hoang 《Zeitschrift fur Physik C Particles and Fields》1994,63(2):269-273
The similarity of rapidity distributions of hadrons frompp and $\bar p$ p withe + e ?→π±+... implies a scaling forE cm, reflecting the quark-quark interaction of particle production by $\bar p$ /p+p. This scaling relates the meson multiplicity fromh+p→m $\bar m$ +... to the Fermi-Landau law $n_{ch} = a\sqrt {E_{cm} } $ fore + e ? collisions, without free-parameters, threshold energy being taken into account including the mass of quarks constituent of the projectile and the target, the coefficient behaves like bremsstrahlung a~1/m 2. 相似文献
4.
J. Allday J. R. Fry P. Mason G. D. Patel F. Meijers W. J. Metzger C. De Marzo M. De Palma C. Favuzzi G. Maggi F. Posa A. Ranieri G. Selvaggi P. Spinelli P. Malecki K. Olkiewicz P. Stopa I. Derado V. Eckardt J. Fent P. Freund H. J. Gebauer A. Manz K. P. Pretzl N. Schmitz P. Seyboth J. Seyerlein G. Wolf NA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1988,40(1):29-39
The results of an analysis of streamer chamber data from the NA5 experiment are presented. Topological cross sections forpp and \(\bar p\) p interactions and strange neutral particle production at 200 GeV/c have been measured and ( \(\bar p\) p?pp) difference cross sections have been determined. Multiplicity moments were calculated. 相似文献
5.
6.
T. F. Hoang 《Zeitschrift fur Physik C Particles and Fields》1993,60(3):535-540
The rest-frame of secondaries frompp collisions determined by the covariant Boltzmann factor is found to be independent of the massm of the secondary. In this frame, the hadron production behaves like bremsstrahlung:n(m)~W * (m)/m 2,W * (m) being the available energy. This multiplicity law fitsp+p→m+? at 400 GeV/c of NA 27 Collaboration without free-parameters. Extended top-nucleus and heavy-ion collisions, assuming a mean-free-path of collision between the incident and the target nucleon to be ~2.80 fm and 1.63 fm respectively, it accounts forn(K ?) and \(n(\bar \Lambda )\) of CERN-SPS experiments and theK ?/π? ratio of BNL experiments. 相似文献
7.
R. Göttgens J. M. Kohli P. Sixel U. Gensch H. Vogt Y. Goldschmidt-Clermont D. R. O. Morrison R. T. Ross S. Squarcia J. Chwastowski M. W. Krasny L. Suszycki W. Zielinski P. Girtler D. Kuhn K. W. J. Barnham P. R. S. Wright M. Zomorrodian D. I. Patalakha A. M. Moissev J. MacNaughton F. Mandl M. Markytan J. Mittendorfer M. Bardadin-Otwinowska A. Jachołkowska M. Szczekowski 《Zeitschrift fur Physik C Particles and Fields》1983,19(4):283-290
The inclusive proton diffraction dissociation cross sections in 16, 32, and 110 GeV/cK ? p interactions are determined from the spike nearx=1 in the inclusive negative particle spectra and are compared to those obtained inK?p interactions using other selection methods at various energies. The same procedure is applied to events containing aV 0 in order to obtain the cross section for diffractive \(s\bar s\) production. While the total cross section for proton diffraction is found to be approximately constant in the energy range studied here, proton diffraction yielding an \(s\bar s - pair\) is found to increase significantly. In particular it is almost constant at 85 μb forΛ 0 and Σ production but for \(NK\bar K\) it rises from zero at 16 GeV.c to about 200 μb at 110 GeV/c. From the result for \(s\bar s\) diffractive production an estimate for the \(c\bar c\) diffractive production cross section of approximately 1–10 μb at 110 GeV/c is obtained. 相似文献
8.
B. M. Whyman P. Johnson P. Mason H. Muirhead G. D. Patel G. W. van Apeldoorn D. Harting D. J. Holthuizen B. J. Pijlgroms M. M. H. M. Rijssenbeek 《Zeitschrift fur Physik C Particles and Fields》1982,12(3):203-216
We present results on inclusive baryon and meson resonance production in \(\bar pp\) interactions at 7.3 GeV/c. Total inclusive and semi-inclusive cross sections are given for Δ(1232),∑ *(1385), ?0,f andK *±(892) production. For the meson resonances separation into annihilation and non-annihilation components has been made, the annihilation component being dominant at this energy. We find that the energy dependence of inclusive cross sections for ?0 production inpp interactions and \(\bar pp\) non-annihilations shows a type of scaling behaviour previously reported for ?, ψ, ψ′ and ? production inpp interactions.Δ ++, ?0 andK *± production are studied in terms of Feynmanx,y * andp T 2 . For the vector mesons we compare they * andx dependences with the predictions of simple quark models. 相似文献
9.
The prototype of a $\bar{K}$ nuclear cluster, K ???pp, has been investigated using effective $\bar{K}N$ potentials based on chiral SU(3) dynamics. Variational calculation shows a bound state solution with shallow binding energy B(K ???pp)?=?20±3 MeV and broad mesonic decay width $\Gamma(\bar{K}NN \rightarrow \pi Y N)=40$ –70 MeV. The $\bar{K}N(I=0)$ pair in the K ???pp system exhibits a similar structure as the Λ(1405). We have also estimated the dispersive correction, p-wave $\bar{K}N$ interaction, and two-nucleon absorption width. 相似文献
10.
N. V. Shevchenko 《Few-Body Systems》2014,55(8-10):745-748
A chiral-motivated \({\bar{K}N - \pi\Sigma - \pi\Lambda}\) potential was constructed and used in Faddeev calculations of different characteristics of \({\bar{K}NN - \pi\Sigma N}\) system. First of all, binding energy and width of the K ? pp quasi-bound state were newly obtained. The low-energy K ? d scattering amplitudes, including scattering length, together with the 1s level shift and width of kaonic deuterium were calculated. Comparison with the results obtained with the phenomenological \({\bar{K}N - \pi\Sigma}\) potential demonstrates that the chiral-motivated potential gives more shallow K ? pp state, while the characteristics of K ? d system are less sensitive to the form of \({\bar{K}N}\) interaction. 相似文献
11.
A. Breakstone R. Campanini H. B. Crawley G. M. Dallavalle K. Doroba D. Drijard F. Fabbri A. Firestone H. G. Fischer H. Frehse W. Geist R. Gokieli M. Gorbics P. Hanke M. Heiden W. Herr P. G. Innocenti E. E. Kluge J. W. Lamsa T. Lohse W. T. Meyer G. Mornacchi T. Nakada M. Panter A. Putzer K. Rauschnabel F. Rimondi R. Sosnowski M. Szczekowski O. Ullaland D. Wegener 《Zeitschrift fur Physik C Particles and Fields》1984,21(4):321-325
Inclusive cross sections forΔ ++ production inpp interactions at different ISR energies are presented. The differential cross sectiondσ/dx forΔ ++ production is found to be approximately independent of Feynmanx. No strong energy dependence is seen over the ISR energy range. The topological cross sections ofΔ ++ at \(\sqrt s = 62\) GeV show an appreciable contribution from non-diffractive production mechanisms. An upper limit for theΔ 0 production cross section is determined. 相似文献
12.
U. Gensch R. Klein H. J. Schreiber M. Walter H. Graessler D. Kuhn D. R. O. Morrison F. Triantis R. Barloutaud C. Cochet D. Denegri M. L. Faccini-Turluer A. Givernaud E. P. Kistenev A. A. Minaenko D. I. Patalakha E. Kozlovsky J. Macnaughton France-Soviet Union Collaboration CERN-Soviet Union Collaboration 《Zeitschrift fur Physik C Particles and Fields》1979,2(1):7-10
Antilambda production is studied inK ? p interactions at 32 GeV/c. Both total and differential cross sections are presented. The inclusive \(\bar \Lambda \) production cross section amounts to 109±7 μb. A remarkable energy dependence is observed, σ( \(\bar \Lambda \) ) increasing by a factor of four between 14.3 and 32 GeV/c. Thep ⊥ 2 distribution exhibits an exponential fall-off with a slope of 3.3±0.2 (GeV/c)?2. Most of the \(\bar \Lambda \) 's are emitted in the forward hemisphere. The invariantx distribution increases between 14.3 and 32 GeV/c. Data are presented for \(\bar \Lambda \) production inK - p→Λ \(\bar \Lambda \) +X K - p→ \(\bar \Lambda \) K n +X, andK - p→ \(\bar \Lambda \) p+X. 相似文献
13.
A. N. Shelkovenko 《Zeitschrift fur Physik C Particles and Fields》1989,43(4):683-692
Following the arguments of QCD, a proposed model takes into account the significant difference ofpp andp \(\bar p\) elasticd σ/dt discovered at the ISR. An expression forC-odd exchange is discussed and comparison with data is made. Starting from the ISR energies, the model is shown to describe well the data in a wide range of transverse momenta 0≦?t≦10 (GeV/c)2 (including the Coulomb-nuclear interference region). Several peculiar predictions of the model will be testable in the TeV energy range and beyond. 相似文献
14.
C. Kourkoumelis L. K. Resvanis T. A. Filippas E. Fokitis A. M. Chops S. Iwata R. B. Palmer D. C. Rahm P. Rehak I. Stumer C. W. Fabjan T. Fields D. Lissauer I. Mannelli P. Mouzourakis A. Nappi W. J. Willis 《Zeitschrift fur Physik C Particles and Fields》1980,5(2):95-104
The inclusive cross-section for π0 production near 90° inpp collisions at the CERN Intersecting Storage Rings has been studied for thep T range 3<p T <16GeV/c at four different centre-of-mass energies ( \(\sqrt s = 30.6\) , 44.8, 52.7, and 62.8 GeV). In this experiment the two photons from the π0→yy decay were resolved and measured separately forp T values up to 10 GeV/c. Results indicate an agreement with thep T ?8 behaviour for the lower values ofp T and a slower decrease of the cross-section for the higher values ofp T . The high-p T data deviate from the scaling expressionp T ?n F(x T ), which holds for the lowerp T values (p T <8GeV/c). 相似文献
15.
A phenomenological model is presented which regards the system after collision as a single entity that emits hadrons directly. The evolution of this entity gives a new two parameter distribution which fits the high energypp, \(\bar pp\) ,e + e ?, π+ p andK + p data reasonably well. The entity emits hadrons along the rapidity axis and exhibits intermittency behaviour under certain conditions. 相似文献
16.
H. Neufeld 《Zeitschrift fur Physik C Particles and Fields》1983,17(2):145-151
The production ofW bosons in electronpositron colliding beams below theW + W ? threshold is discussed. The corresponding reactions \(e^ + e^ - \to l^ \pm W^ \mp \mathop {\nu _l }\limits^{( - )} \) yield total cross-sections of the order of 10?37 cm2 (forl=e) and 10?38 cm2 (forl=μ). The total cross-sections as well as the angular and energy distributions of theW boson in \(e^ + e^ - \to e^ \pm W^ \mp \mathop {\nu _e }\limits^{( - )} \) are sensitive to the magnetic moment of theW. So, with this reaction, not onlyW bosons can be produced but also the gauge nature of the interaction can be tested. The decay \(Z^0 \to l^ \pm W^ \mp \mathop {\nu _l }\limits^{( - )} \) is discussed in view of its observation ine + e ? experiments. Finally the crosssections ofe - p→ν e W - X + are computed. They are of the order of 10?38 cm2 for \(\sqrt s \simeq 200\) GeV. 相似文献
17.
The exclusive reactionpp→ppπ+ π? has been studied using the SFM spectrometer at ISR energies of \(\sqrt s = 24\) and 63 GeV. The cross section in the double pomeron exchange region defined by |x p |>0.9, |y π |<1 is 28±6, 23(+13, ?6) and 29(+29, ?10)μb, respectively. The ππ mass spectrum is dominated by an 1/m ππ 2 part, as expected for pomeron pomeron scattering. In addition, thef(1, 270) resonance is clearly distinguished. There are no further resonance signals, which could be assigned to glueball candidates expected in the 1,000 MeV region. Compared to photon photon scattering, the ratio of continuum tof-resonance production cross sections is significantly larger in pomeron pomeron scattering. 相似文献
18.
T. F. Hoang 《Zeitschrift fur Physik C Particles and Fields》1991,49(2):311-316
The rapidity distributions of inclusive \(e^ + e^ - \to h\bar h + \cdot \cdot \cdot\) of PEP and DESY experiments are analyzed in terms of the covariant partition temperatureT p model. The estimates ofT p * in the fireball system are comparable to the conventional temperature, the energy dependence follows approximately Stefan's law, the radius of the specific volume ralative to the energy density being ~1.18 fm. In the c.m.s. of collision, \(T_p = AW^a (W = \sqrt s in GeV)\) witha=0.60±0.05 andA=0.256±0.006, it is found \(T_p \cong {W \mathord{\left/ {\vphantom {W {\tfrac{3}{2}\left\langle {n_ \pm } \right\rangle }}} \right. \kern-0em} {\tfrac{3}{2}\left\langle {n_ \pm } \right\rangle }}\) . These properties hold also for \(\bar pp\) collision, but not forpp→π?+... 相似文献
19.
A separable representation of theS-wave Paris potential and a phase-shift equivalent Yamaguchi-type potential significantly differing in their off-shell behaviours are used to calculate second-order polarization observables of elastic nucleon-deuteron scattering atE D=10 and 20MeV. Off-shell effects are found that stem from differences in the nuclear interaction in the inner regionr?1.2 fm. Adding approximate Coulomb-distortion contributions to the purely nuclear Faddeev amplitudes proton-deuteron predictions are obtained. Coulomb effects are not found to be negligible. Comparison with experimental data, in particular, the spin-correlation parameterC y,y of the reaction \({}^1\vec H(\vec d,d)^1 H\) forE D=10MeV vector-polarized deuterons and the spin-transfer coefficientsK y y′ ,K x x′ andK z x′ for \({}^2H(\vec p,\vec p)^2 H\) atE p=10MeV, prefer the interaction model that contains an intermediate-range repulsion. 相似文献
20.
H. H. Krause W. Arnold H. Berg J. Ulbricht G. Clausnitzer 《Zeitschrift für Physik A Hadrons and Nuclei》1979,293(4):343-349
The aim of this work was the unambiguous proof of the existence of the Mott-Schwinger interaction. The analyzing power of the \(\vec p - \) 12C elastic scattering was measured in the energy range from 450 to 600 keV for scattering anglesθ Lab=90° and 120° with an overall accuracy up toΔA=1·10?4. The data can be described very well with theR-matrix formalism including Mott-Schwinger interaction. Omitting this interaction large discrepancies occur. 相似文献