Browsing by Author "S.B. Beri"

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Charged charm production in proton-emulsion interactions at 400 GeV/c
(Springer-Verlag, 1985) T. Aziz; S. Ahmad; H. Ahrar; S.B. Beri; V.S. Bhatia; S.N. Ganguli; S.K. Gupta; V.K. Gupta; A. Gurtu; G.L. Kaul; Manjit Kaur; A.R. Khan; S. Kumar; P.K. Malhotra; L.K. Mangotra; I.S. Mittra; Y. Prakash; N.K. Rao; M. Shafi; M. Shyam; G. Singh; S.K. Tuli
A study of charged charm production is made at 400 GeV incident energy of protons in nuclear emulsion. A total of 7005 primary stars have been scrutinized to look for charm particle decays in the forward cone within a decay distance of 100-1,000 μm (3,056 stars) and 100-2,000 μm (3,949 stars). In all 10 charm candidates decaying to 3 charged particles plus neutrals have been observed. Background due to secondary interactions for events of such topology is estimated to be ≈3. Background due to strange particle decays is estimated to be negligible. The rest of the events are attributed to Λc+ and D± decays. This leads to a value of 91±35 μb/nucleon for the total charged charm production cross section. Using production cross section for D± from other experiments we obtain Λc+ production cross section as 62±27 μb/nucleon. Two cases of pair production of charm have been seen. © 1985 Springer-Verlag.
Neutral charm production in 400 GeV proton-emulsion interactions
(Springer-Verlag, 1984) T. Aziz; S. Ahmad; H. Ahrar; S.B. Beri; V.S. Bhatia; S.N. Ganguli; S.K. Gupta; V.K. Gupta; A. Gurtu; M. Irfan; R.R. Joseph; G.L. Kaul; Manjit Kaur; S. Kumar; P.K. Malhotra; L.K. Mangotra; I.S. Mittra; Y. Prakash; N.K. Rao; M. Shafi; M. Shyam; S.K. Tuli
A search has been carried out for neutral charm production in 5,108 proton-emulsion interactions at 400 GeV/c. Nine charm candidates have been observed in our fiducial volume which extends from 100 μm-1,000 μm in the forward cone. One of these is a 4-prong and the others are 2-prong events with opening angle>10 mrad and momenta of both decay tracks>150 MeV/c. Search for associated charm decays was made in an extended fiducial volume around the primary stars of these nine candidates. This yielded two neutral 2-prong events, one associated with the 4-prong and the other with a 2-prong candidate. All unassociated candidates are consistent with being backgrounds due to Ks, Λ decays, neutral interactions and γ conversions whereas the background to associated events is negligible. Based on the two associated decays the inclusive cross section for D0, -0 production is determined as 27±20 μb/nucleon. Detailed measurements on the 4-prong candidate lead to the identification of one decay track as an electron and another as a kaon. This is interpreted as a semi-leptonic, Cabbibo favoured D0/D-0 decay. © 1984 Springer-Verlag.
Search for anomalous fragments in 1.8A-GeV Ar40 reactions in nuclear emulsions
(1985) R. Bhanja; R. Joseph; S.K. Tuli; S.B. Beri; V.S. Bhatia; G. Kaur; M. Kaur; I.S. Mittra; K.B. Bhalla; A. Bharti; S. Lokanathan; S.K. Gupta; V.K. Gupta; G.L. Kaul; V. Kumar; L.K. Mangotra; Y. Prakash; N.K. Rao; S. Sankhydhar; S. Satti; G. Claesson; S. Garpman; N.Y. Herrström; B. Jakobsson; I. Lund; B. Norén; A. Oskarsson; I. Otterlund; S. Persson; M.M. Sherif; K. Söderström
Results are presented from an investigation of the mean free path in nuclear emulsion of multiply charged fragments, produced by 1.8A-GeV argon nuclei. Charge identification of 6965 fragments with charges Z2, producing 2192 secondary interactions, has been made. No dependence of the mean free path on the distance from the preceding collision is observed and thus our result is consistent with the nonexistence of anomalons. © 1985 The American Physical Society.
Search for anomalous interaction mean free paths of charge, 2≦Z≦18 projectile fragments in emulsions exposed to 1.8 A GeV40Ar ions
(Springer-Verlag, 1987) S.B. Beri; K.B. Bhalla; R. Bhanja; A. Bharti; V.S. Bhatia; G. Claesson; S. Garpman; S.K. Gupta; V.K. Gupta; N.Y. Herrstrom; B. Jakobsson; R. Joseph; G.L. Kaul; G. Kaur; M. Kaur; S. Kitroo; V. Kumar; S. Lokanathan; I. Lund; L.K. Mangotra; I.S. Mitra; S. Mookerjee; B. Norén; A. Oskarsson; I. Otterlund; Y. Prakash; S. Persson; N.K. Rao; S. Sankhyadhar; S. Satti; M.M. Sherif; K. Söderström; S.K. Tuli
40Ar-emulsion interactions are studied, to investigate the question of anomalons, in two G- 5 emulsion stacks. In about 4600 primary interactions, projectile fragments of Z≧2 for all generations have been followed until they interact or leave the stack. After careful estimation of charges of these fragments, variation of their mean free paths is studied as a function of distance from the preceding interaction. Generation effect, Nh dependence and production angle effect are investigated. In addition multi-chain events are analysed separately. Our results do not show anomalons at the 6% level and are consistent with non-occurrence of anomalons. However, this experiment is not sensitive enough to rule out anomalons (with a mfp of the order of 2 to 3 cm) produced at about 1% (or less) level. © 1987 Springer-Verlag.