1982 Vol. 6, No. 1
Display Method: |
Abstract:
In this paper, the design, construction and characteristics of a 70cm streamerchamber system are deseribed. A very fast pulse with rise time 2 ns and duration 10ns has been successfullyobtained by using a four-spark-gap cylindrical Blumlein line with a 25 stage Marxgenerator (up to 600kV) connected to it. The output pulse of the Blumlein line isthen fed to the chamber, via heteromorphic transmission line with pulse shapeminimum distortion. The system are triggered by three-fold large area scintillation counter telescopeto pick up particle of the cosmic ray traversing the sensitive volume of the chamber.The coincidence-counting rate is ～5 particles/min., the resolving time is 10ns, andthe ratio of the true-accidental coincidence is more than 700. The chamber has two 15 cm gaps and is 70 cm long, 50 cm wide, with 30Ω ofcharacteristic impedence. In order to photograph through the electrodes, the central and the ground electrodes towards the cameras are made of 0.2mm diameter beryl-lium-copper wire stands spaced 2 mm apart, with transparency～90%. Pure neon and mixtures of neon-helium gas were used to fill the chamber, oneatmosphere, and a cycling and purifier system were designed to maintain its purity.The gas is passed through type 5A and 13x molecular sieve operated at room andliquid -nitrogen temperature to remove CO2, H2O and O2, N2, respectively. The im-purities of the chamber gas can be reduced to 0.2% within 2hr., at the gas flow rate500 1/hr. All photographs are taken with one or two oscilloscope cameras on 35mm film of28 DIN. A demagnification 30x and a resolution 30 line pairs/mm at the maximumaperture (f/2) are used. The sizes of the visual streamers were estimated about3 to 4 mm in diameter (view along the E field), and 10 to 15 mm long (view perpen-dicular to the E field). The delay time between the penetration of charged particle and the supply of thehigh voltage pulse on the chamber was ～3.5μs. The system was suggested in June1975. The whole facility began to mount and adjust in January 1979, and the strea-mer tracks were seen on July 26, 1979. We plan to make the performance tests, to reduce the delay time of the system,and to improve the chamber suitable for use in high energy accelerator and cosmic-ray experiments in the near future.
In this paper, the design, construction and characteristics of a 70cm streamerchamber system are deseribed. A very fast pulse with rise time 2 ns and duration 10ns has been successfullyobtained by using a four-spark-gap cylindrical Blumlein line with a 25 stage Marxgenerator (up to 600kV) connected to it. The output pulse of the Blumlein line isthen fed to the chamber, via heteromorphic transmission line with pulse shapeminimum distortion. The system are triggered by three-fold large area scintillation counter telescopeto pick up particle of the cosmic ray traversing the sensitive volume of the chamber.The coincidence-counting rate is ～5 particles/min., the resolving time is 10ns, andthe ratio of the true-accidental coincidence is more than 700. The chamber has two 15 cm gaps and is 70 cm long, 50 cm wide, with 30Ω ofcharacteristic impedence. In order to photograph through the electrodes, the central and the ground electrodes towards the cameras are made of 0.2mm diameter beryl-lium-copper wire stands spaced 2 mm apart, with transparency～90%. Pure neon and mixtures of neon-helium gas were used to fill the chamber, oneatmosphere, and a cycling and purifier system were designed to maintain its purity.The gas is passed through type 5A and 13x molecular sieve operated at room andliquid -nitrogen temperature to remove CO2, H2O and O2, N2, respectively. The im-purities of the chamber gas can be reduced to 0.2% within 2hr., at the gas flow rate500 1/hr. All photographs are taken with one or two oscilloscope cameras on 35mm film of28 DIN. A demagnification 30x and a resolution 30 line pairs/mm at the maximumaperture (f/2) are used. The sizes of the visual streamers were estimated about3 to 4 mm in diameter (view along the E field), and 10 to 15 mm long (view perpen-dicular to the E field). The delay time between the penetration of charged particle and the supply of thehigh voltage pulse on the chamber was ～3.5μs. The system was suggested in June1975. The whole facility began to mount and adjust in January 1979, and the strea-mer tracks were seen on July 26, 1979. We plan to make the performance tests, to reduce the delay time of the system,and to improve the chamber suitable for use in high energy accelerator and cosmic-ray experiments in the near future.
Abstract:
We calcnlate the cross section of Axion Production in e+ e- annihilation, andsuggeste that one can search for Axion in the e+e- annihilation experiment using β+Source. The requirements of detectors used in such experiment is alro discussed.
We calcnlate the cross section of Axion Production in e+ e- annihilation, andsuggeste that one can search for Axion in the e+e- annihilation experiment using β+Source. The requirements of detectors used in such experiment is alro discussed.
Abstract:
Usually the study of gauge field is based on the wave function. By discussing thebehaviour of Dirac particles in gravitation, one has a famous difficulty, that is, thewave functions appear as scalars under general coordinate transformations. In thispaper, a method is suggested to constitute the gauge fields directly from algebraicstructures, Lie algebra and Jordan algebra. We introduce a concept called represen-tation group of algebras, the transformations, of wave function are connected with therepresentation group. The global and local representation groups are connected withglobal and local transformations of wave function respectively. According to thismethod we find that it is equivalent to the usual one for all of the problems concernedwith internal freedom as Yang-Mills field etc. For spinors, one can introduce gravi-tation by changing the algebraic structure, one find that the vierbein is unneccessaryand the wave functions transform as spinors corresponding to Dirac theory. Somerelated problems are also discussed.
Usually the study of gauge field is based on the wave function. By discussing thebehaviour of Dirac particles in gravitation, one has a famous difficulty, that is, thewave functions appear as scalars under general coordinate transformations. In thispaper, a method is suggested to constitute the gauge fields directly from algebraicstructures, Lie algebra and Jordan algebra. We introduce a concept called represen-tation group of algebras, the transformations, of wave function are connected with therepresentation group. The global and local representation groups are connected withglobal and local transformations of wave function respectively. According to thismethod we find that it is equivalent to the usual one for all of the problems concernedwith internal freedom as Yang-Mills field etc. For spinors, one can introduce gravi-tation by changing the algebraic structure, one find that the vierbein is unneccessaryand the wave functions transform as spinors corresponding to Dirac theory. Somerelated problems are also discussed.
Abstract:
In the literature, the overlap integral of a transition (e.g. 1-→0-+γ) is usuallywritten asI = ∫d3xeiσx/2φf*(x')φi(x) Using Bethe-Salpeter equation with instantaneous approximation, we arrive at adifferent result which depends obviously on the mass of the quarks. Our result willapproximate the above expression only when the binding energy can be neglected.
In the literature, the overlap integral of a transition (e.g. 1-→0-+γ) is usuallywritten asI = ∫d3xeiσx/2φf*(x')φi(x) Using Bethe-Salpeter equation with instantaneous approximation, we arrive at adifferent result which depends obviously on the mass of the quarks. Our result willapproximate the above expression only when the binding energy can be neglected.
Abstract:
We discuss the CP violation problem of SU(7) models of Grand Unified Theoryincluding four genarations[1,2]. It is shown that if we properly choose the complex phaseangles in quark mass matrix elements, we are able to obtain the CP violation phaseangle which agrees well with the experimental value. If the Higgs potential is pro-perly choosen we find that the strong CP violation parameter θ is equal to zero atthe tree level.
We discuss the CP violation problem of SU(7) models of Grand Unified Theoryincluding four genarations[1,2]. It is shown that if we properly choose the complex phaseangles in quark mass matrix elements, we are able to obtain the CP violation phaseangle which agrees well with the experimental value. If the Higgs potential is pro-perly choosen we find that the strong CP violation parameter θ is equal to zero atthe tree level.
Abstract:
A relativistic equation of motion of a two particle system under the constraints pi2-mi2-U(x2)=0.(i=1,2), where U(x2) is an infinite spherical square well poten-tial, is applied to the SU(4) quark model of mesons. A set of linear mass relations areobtained. Instead of the linear relation between J and M2, the Regge trajectory ob-tained is a relation between pnl2 and M2, where ζnlπ are zeros of the spherical Besselfunctions. The new trajectory seems more satisfactory than the former one.
A relativistic equation of motion of a two particle system under the constraints pi2-mi2-U(x2)=0.(i=1,2), where U(x2) is an infinite spherical square well poten-tial, is applied to the SU(4) quark model of mesons. A set of linear mass relations areobtained. Instead of the linear relation between J and M2, the Regge trajectory ob-tained is a relation between pnl2 and M2, where ζnlπ are zeros of the spherical Besselfunctions. The new trajectory seems more satisfactory than the former one.
Abstract:
Considering ψ (4030) as a semi stable bound state of D*D* instead of exitedstate of J/ψ, the spectra of the J/ψ family can de described by the wave equation of har-monic oscillator with mass squared eigen values. The case is similar with that of the or-dinary mesons. The only difference is that the gap of energy level squared for J/ψfamily is as twice large as the ordinary hadrons. The similar conclusion is also valid tothe γ family with energy level gap 5.6 times larger than the ordinary hadrons. In edition, the mixing of S and D wave induced by tensor force is calculated and the energylevel of ψ(3770) with D wave dominance is obtained.
Considering ψ (4030) as a semi stable bound state of D*D* instead of exitedstate of J/ψ, the spectra of the J/ψ family can de described by the wave equation of har-monic oscillator with mass squared eigen values. The case is similar with that of the or-dinary mesons. The only difference is that the gap of energy level squared for J/ψfamily is as twice large as the ordinary hadrons. The similar conclusion is also valid tothe γ family with energy level gap 5.6 times larger than the ordinary hadrons. In edition, the mixing of S and D wave induced by tensor force is calculated and the energylevel of ψ(3770) with D wave dominance is obtained.
Abstract:
Within the framework of the Glauber theory, we divide the many particle systeminto two subsystems formed. by the "valence" particles and "sea" particles respective-ly. Then the multiple scattering amplitudes can be divided into "sea","sea","sea","valence", "valence","sea", and "valence","valence" multiple scattering amplitude.For the calculations of these different amplitudes different effective approximatemethods are proposed, Finally, for "sea"."sea". "sea""valence", "valence" "sea"and "valence"."valence" processes, we obatain the respective S-matrices which phy-sically clear and convenient in calculation.
Within the framework of the Glauber theory, we divide the many particle systeminto two subsystems formed. by the "valence" particles and "sea" particles respective-ly. Then the multiple scattering amplitudes can be divided into "sea","sea","sea","valence", "valence","sea", and "valence","valence" multiple scattering amplitude.For the calculations of these different amplitudes different effective approximatemethods are proposed, Finally, for "sea"."sea". "sea""valence", "valence" "sea"and "valence"."valence" processes, we obatain the respective S-matrices which phy-sically clear and convenient in calculation.
Abstract:
By analyzing the experimental data of the hypernuclei, we propose a hypothesisthat the single baryon binding energy satisfies the SU(3) uintary symmetry. By thissuggestion, some experimental facts in this field can be explained and we also proposethe possibility of the existence of excited states of the hyper [1] nuclei. Some propertiesof this [1] hyper-nuclei is also pointed out.
By analyzing the experimental data of the hypernuclei, we propose a hypothesisthat the single baryon binding energy satisfies the SU(3) uintary symmetry. By thissuggestion, some experimental facts in this field can be explained and we also proposethe possibility of the existence of excited states of the hyper [1] nuclei. Some propertiesof this [1] hyper-nuclei is also pointed out.
Abstract:
QCD perturbation theory for confined quarks and gluons (inhadrons) is discussed.Based on the equivalent potential for the quark-gluon interaction derived, the energyshifts of hadrons and hadron mass difference in MIT bag (cavity) model and correcpond-ing approximation of the w. f. with Gassian form are calculated.
QCD perturbation theory for confined quarks and gluons (inhadrons) is discussed.Based on the equivalent potential for the quark-gluon interaction derived, the energyshifts of hadrons and hadron mass difference in MIT bag (cavity) model and correcpond-ing approximation of the w. f. with Gassian form are calculated.
Abstract:
In the I. B. M., when s, d, g bosons are presented, the boson Hamiltonian has thestructure of group U(15). This paper deals with the various chains of subgroups ofgroap U(15). Especially, the following chains:SU(15)
SU(3)SO(3), SU(15)SU(5)SO(5)SO(3), U(15)U(14)SO(5)SO(3).are studied in detail, The formulae of the energy spectra are also given.
In the I. B. M., when s, d, g bosons are presented, the boson Hamiltonian has thestructure of group U(15). This paper deals with the various chains of subgroups ofgroap U(15). Especially, the following chains:SU(15)
SU(3)SO(3), SU(15)SU(5)SO(5)SO(3), U(15)U(14)SO(5)SO(3).are studied in detail, The formulae of the energy spectra are also given.
Abstract:
In this paper semi-microscopic nuclear matter approach is introduced to calculatethe microscopic optical potential. The first and second order mass operator in sym-metric nuclear matter is derived with Skyrme effective interactions and the real andimaginary part of the optical potential for finite nuclei is obtained by applying alocal density approximation. The five kinds of the different parameters of Skyrmeinteractions Ⅱ-Ⅵ are used and compared with the experimental data to study how wellthese Skyrme interactions can work for our purposes. Our results obtained in such asimple way seem to be to some extent comparable with those obtained with "nuclearmatter approach" and "nuclear structure approach" without adjusting the parame-ters of the Skyrme interactions so far.
In this paper semi-microscopic nuclear matter approach is introduced to calculatethe microscopic optical potential. The first and second order mass operator in sym-metric nuclear matter is derived with Skyrme effective interactions and the real andimaginary part of the optical potential for finite nuclei is obtained by applying alocal density approximation. The five kinds of the different parameters of Skyrmeinteractions Ⅱ-Ⅵ are used and compared with the experimental data to study how wellthese Skyrme interactions can work for our purposes. Our results obtained in such asimple way seem to be to some extent comparable with those obtained with "nuclearmatter approach" and "nuclear structure approach" without adjusting the parame-ters of the Skyrme interactions so far.
Abstract:
We discuss the variance of the charge distribution in the heavy ion deep inelasticcollision on the basis of the Langevin equation. In order to explain the difference ofthe initial slope (early stage) of the charge distribution for the different reactionsystems and different bombarding energy, an initial condition of the charge drift inthe early stage of Dic is introduced. It is given by the harmonic or inhamonic motionaround the zero point and closely depends on the nuclear structure and incident energy.The difference of the inertial mass and stiffness parameter may be the one of thereason for the difference of charge transfer. In addition we also analyse the charac-terstic of the inertial mass parameter.
We discuss the variance of the charge distribution in the heavy ion deep inelasticcollision on the basis of the Langevin equation. In order to explain the difference ofthe initial slope (early stage) of the charge distribution for the different reactionsystems and different bombarding energy, an initial condition of the charge drift inthe early stage of Dic is introduced. It is given by the harmonic or inhamonic motionaround the zero point and closely depends on the nuclear structure and incident energy.The difference of the inertial mass and stiffness parameter may be the one of thereason for the difference of charge transfer. In addition we also analyse the charac-terstic of the inertial mass parameter.
Abstract:
In present paper, a non-classical method of obtaining the decay constant andhalf-life of 99mTc was introduced. The results were compared with that obtained bythe classical method of the least square analysis. The half-life by non-classioal me-thod is 6.006±0.004 hours, that by classical method is 6.009±0.005 hours.
In present paper, a non-classical method of obtaining the decay constant andhalf-life of 99mTc was introduced. The results were compared with that obtained bythe classical method of the least square analysis. The half-life by non-classioal me-thod is 6.006±0.004 hours, that by classical method is 6.009±0.005 hours.
Abstract:
As a generalization of the work [1], a general formula on C-G series of U(3)group is given. It is beautiful and effective.
As a generalization of the work [1], a general formula on C-G series of U(3)group is given. It is beautiful and effective.
Abstract:
A simple method of four band mixture describing the high spin states of even-even nuclei is proposed. Multi-band structure is discussed. The spectra and 2J～ω2curves of four even parity bands in Er164 is calculated in this model. The results arefound to be in a reasonable agreement with experimental data.
A simple method of four band mixture describing the high spin states of even-even nuclei is proposed. Multi-band structure is discussed. The spectra and 2J～ω2curves of four even parity bands in Er164 is calculated in this model. The results arefound to be in a reasonable agreement with experimental data.
Abstract:
Inclusive distributions of longitudinal momentum and energy ((S/β) (dσ/dxp)and (S/β) (dσ/dxE)) in a quark jat for e+ e- collidiny is calculated (√S～7GeV), fased onrandomly producing wee quarks and phase-space eonsideration. Excellent fits areobtained. In addition, a two-particle correlation dσ/(dxIEdx2E) is also given, which ex-pects experimental tests.
Inclusive distributions of longitudinal momentum and energy ((S/β) (dσ/dxp)and (S/β) (dσ/dxE)) in a quark jat for e+ e- collidiny is calculated (√S～7GeV), fased onrandomly producing wee quarks and phase-space eonsideration. Excellent fits areobtained. In addition, a two-particle correlation dσ/(dxIEdx2E) is also given, which ex-pects experimental tests.
IF: 3.6
Monthly founded in 1977
Sponsored by:
ISSN 1674-1137 CN 11-5641/O4
Original research articles, Ietters and reviews Covering theory and experiments in the fieids of
- Particle physics
- Nuclear physics
- Particle and nuclear astrophysics
- Cosmology
Author benefits
- A SCOAP3 participating journal - free Open Access publication for qualifying articles
- Average 24 days to first decision
- Fast-track publication for selected articles
- Subscriptions at over 3000 institutions worldwide
- Free English editing on all accepted articles
News
- Chinese Physics C Outstanding Reviewer Award 2023
- Impact factor of Chinese Physics C is 3.6 in 2022
- 2022 CPC Outstanding Reviewer Awards
- The 2023 Chinese New Year-Office closure
- ãChinese Physics CãBEST PAPER AWARDS 2022
Cover Story
- Cover Story (Issue 4, 2024) | Advancing gravitational wave astronomy: AI-enhanced detection and real-time analysis in the presence of glitches
- Cover Story (Issue 3, 2024) | First measurement of the ground-state mass of 22Al helpsto evaluate the ab-initio theory
- Cover Story (Issue 2, 2024) | Quark/gluon taggers light the way to new physics
- Cover story (Issue 6, 2023) ï½Joint constraints on cosmological parameters using future multi-band gravitational wave standard siren observations
- Cover Story (Issue 5, 2023) | Production and decay of polarized hyperon-antihyperon pairs
Advertising
