Model-independent Z' searches at modern colliders

The model-independent constraints on the Abelian Z' couplings from the LEP data are applied to estimate the Z' production in experiments at hadron colliders. The Z' contribution to the Drell-Yan process at modern hadron colliders is analyzed. The results are compared with model-dependent predictions and present experimental data from the Tevatron and the LHC. The lower bounds on the Z' mass are derived and the Z' discovery limit in the LHC experiments is found.С помощью модельно-независимых ограничений на константы связи абелевого Z'-бозона получены оценки процессов рождения Z' в экспериментах на адронных коллайдерах. Изучен вклад Z'-бозона в процесс Дрелла-Яна. Проведено сравнение полученных результатов с модельно-зависимыми предсказаниями и экспериментальными данными ускорителей Tevatron и LHC. Получена нижняя граница значения массы Z'-бозона, а также предельные значения массы, при которых Z' будет обнаружен в эксперименте LHC.За допомогою модельно-незалежних обмежень констант зв’язку абелевого Z'-бозона отримано оцінки процесів народження Z'-бозона в експериментах на гадронних колайдерах. Досліджено внесок Z' в процес Дрелла-Яна. Виконано порівняння отриманих результатів з модельно-залежними результатами та експериментальними даними прискорювачів Tevatron та LHC. Отримана нижня границя маси Z'-бозона, а також граничні значення маси, при яких Z'-бозон буде знайдено в експериментах LHC

Identification of extra neutral gauge bosons at the International Linear Collider

Heavy neutral gauge bosons, Z's, are predicted by many theoretical schemes of physics beyond the Standard Model, and intensive searches for their signatures will be performed at present and future high energy colliders. It is quite possible that Z's are heavy enough to lie beyond the discovery reach expected at the CERN Large Hadron Collider LHC, in which case only indirect signatures of Z' exchanges may occur at future colliders, through deviations of the measured cross sections from the Standard Model predictions. We here discuss in this context the foreseeable sensitivity to Z's of fermion-pair production cross sections at an e^+e^- linear collider, especially as regards the potential of distinguishing different Z' models once such deviations are observed. Specifically, we assess the discovery and identification reaches on Z' gauge bosons pertinent to the E_6, LR, ALR and SSM classes of models, that should be attained at the planned International Linear Collider (ILC). With the high experimental accuracies expected at the ILC, the discovery and the identification reaches on the Z' models under consideration could be increased substantially. In particular, the identification among the different models could be achieved for values of Z' masses in the discovery (but beyond the identification) reach of the LHC. An important role in enhancing such reaches is played by the electron (and possibly the positron) longitudinally polarized beams. Also, although the purely leptonic processes are experimentally cleaner, the measurements of c- and b-quark pair production cross sections are found to carry important, and complementary, information on these searches.Comment: 21 page

Observation Of Very High Energy Cosmic-ray Families In Emulsion Chambers At High Mountain Altitudes (i)

Characteristics of cosmic-ray hadronic interactions in the 1015 - 1017 eV range are studied by observing a total of 429 cosmic-ray families of visible energy greater than 100 TeV found in emulsion chamber experiments at high mountain altitudes, Chacaltaya (5200 m above sea level) and the Pamirs (4300 m above sea level). Extensive comparisons were made with simulated families based on models so far proposed, concentrating on the relation between the observed family flux and the behaviour of high-energy showers in the families, hadronic and electromagnetic components. It is concluded that there must be global change in characteristics of hadronic interactions at around 1016 eV deviating from thise known in the accelerator energy range, specially in the forwardmost angular region of the collision. A detailed study of a new shower phenomenon of small-pT particle emissions, pT being of the order of 10 MeV/c, is carried out and its relation to the origin of huge "halo" phenomena associated with extremely high energy families is discussed as one of the possibilities. General characteristics of such super-families are surveyed. © 1992.3702365431Borisov, (1981) Nucl. Phys., 191 BBaybrina, (1984) Trudy FIAN 154, p. 1. , [in Russian], Nauka, MoscowLattes, Hadronic interactions of high energy cosmic-ray observed by emulsion chambers (1980) Physics Reports, 65, p. 151Hasegawa, ICR-Report-151-87-5 (1987) presented at FNAL CDF Seminar, , Inst. for Cosmic Ray Research, Univ. of TokyoCHACALTAYA Emulsion Chamber Experiment (1971) Progress of Theoretical Physics Supplement, 47, p. 1Yamashita, Ohsawa, Chinellato, (1984) Proc. 3rd Int. Symp. on Cosmic Rays and Particle Physics, p. 30. , Tokyo, 1984, Inst. for Cosmic Ray Research, Univ. of Tokyo(1984) Proc. 3rd Int. Symp. on Cosmic Rays and Particle Physics, p. 1. , Tokyo, 1984Baradzei, (1984) Proc. 3rd Int. Symp. on Cosmic Rays and Particle Physics, p. 136. , Tokyo, 1984Yamashita, (1985) J. Phys. Soc. Jpn., 54, p. 529Bolisov, (1984) Proc. 3rd Int. Symp. on Cosmic rays and Particle Physics, p. 248. , Tokyo, 1984, Inst. for Cosmic Ray Research, Univ. of TokyoTamada, Tomaszewski, (1988) Proc. 5th Int. Symp. on Very High Energy Cosmic-Ray Interactions, p. 324. , Lodz, 1988, Inst. for Cosmic Ray Research, Univ. of Tokyo, PolandHasegawa, (1989) ICR-Report-197-89-14, , Inst. for Cosmic Ray Research, Univ. of TokyoCHACALTAYA Emulsion Chamber Experiment (1971) Progress of Theoretical Physics Supplement, 47, p. 1Okamoto, Shibata, (1987) Nucl. Instrum. Methods, 257 A, p. 155Zhdanov, (1980) FIAN preprint no. 45, , Lebedev Physical Institute, MoscowSemba, Gross Features of Nuclear Interactions around 1015eV through Observation of Gamma Ray Families (1983) Progress of Theoretical Physics Supplement, 76, p. 111Nikolsky, (1975) Izv. Akad. Nauk. USSR Ser. Fis., 39, p. 1160Burner, Energy spectra of cosmic rays above 1 TeV per nucleon (1990) The Astrophysical Journal, 349, p. 25Takahashi, (1990) 6th Int. Symp. on Very High Energy Cosmic-ray Interactions, , Tarbes, FranceRen, (1988) Phys. Rev., 38 D, p. 1404Alner, The UA5 high energy simulation program (1987) Nuclear Physics B, 291 B, p. 445Bozzo, Measurement of the proton-antiproton total and elastic cross sections at the CERN SPS collider (1984) Physics Letters B, 147 B, p. 392Wrotniak, (1985) Proc. 19th Cosmic-Ray Conf. La Jolla, 1985, 6, p. 56. , NASA Conference Publication, Washington, D.CWrotniak, (1985) Proc. 19th Cosmic-Ray Conf. La Jolla, 1985, 6, p. 328. , NASA Conference Publication, Washington, D.CMukhamedshin, (1984) Trudy FIAN, 154, p. 142. , Nauka, Moscow, [in Russian]Dunaevsky, Pluta, Slavatinsky, (1988) Proc. 5th Int. Symp. on Very High Energy Cosmic-Ray Interactions, p. 143. , Lodz, 1988, Inst. of Physics, Univ. of Lodz, PolandKaidalov, Ter-Martirosyan, (1987) Proc. 20th Int. Cosmic-Ray Conf., Moscow, 1987, 5, p. 141. , Nauka, MoscowShabelsky, (1985) preprints LNPI-1113Shabelsky, (1986) preprints LNPI-1224, , Leningrad [in Russian]Hillas, (1979) Proc. 16th Int. Cosmic-Ray Conf., Kyoto, 6, p. 13. , Inst. for Cosmic Ray Research, Univ. of TokyoBorisov, (1987) Phys. Lett., 190 B, p. 226Hasegawa, Tamada, (1990) 6th Int. Symp. on Very High Energy Cosmic-Ray Interactions, , Tarbes, FranceSemba, Gross Features of Nuclear Interactions around 1015eV through Observation of Gamma Ray Families (1983) Progress of Theoretical Physics Supplement, p. 111Ren, (1988) Phys. Rev., 38 D, p. 1404Dynaevsky, Zimin, (1988) Proc. 5th Int. Symp. on Very High Energy Cosmic-Ray Interaction, p. 93. , Lodz, 1988, Inst. of Physics, Univ. of Lodz, PolandDynaevsky, (1990) Proc. 6th Int. Symp. on Very High Energy Cosmic-Ray Interactions, , Tarbes, France(1989) FIAN preprint no. 208, , Lebedev Physical Institute, Moscow(1990) Proc. 21st Int. Cosmic-Ray Conf., Adelaide, 8, p. 259. , Dept. Physics and Mathematical Physics, Univ. of Adelaide, AustraliaHasegawa, (1990) ICR-Report-216-90-9, , Inst. for Cosmic-Ray Research, Univ. of TokyoTamada, (1990) Proc. 21st Int. Cosmic-Ray Conf., Adelaide, 1990, 8. , Dept. Physics and Mathematical Physics, Univ. of Adelaide, AustraliaTamada, (1990) ICR-Report-216-90-9(1981) Proc. 17th Int. Cosmic-Ray Conf., Paris, 5, p. 291(1990) Proc. Int. Cosmic-Ray Conf., Adelaide, 1990, 8, p. 267. , Dept. Physics and Mathematical Physics, Univ. of Adelaide, Australia(1989) Inst. Nucl. Phys. 89-67/144, , preprint, Inst. Nucl. Phys., Moscow State UnivSmilnova, (1988) Proc. 5th Int. Sym. on Very High Energy Cosmic-Ray Interactions, p. 42. , Lodz, 1988, Inst. of Physics, Univ. of Lodz, PolandGoulianos, (1986) Proc. Workshop of Particle Simulation at High Energies, , University of Wisconsin, Madison, USAIvanenko, (1983) Proc. 18th Int. Cosmic-Ray Conf., Bangalore, 1983, 5, p. 274. , Tata Inst. Fundamental Research, Bombay, IndiaIvanenko, (1984) Proc. Int. Symp. on Cosmic-Rays and Particle Physics, p. 101. , Tokyo, 1984, Inst. for Cosmic Ray Research, Univ. of Tokyo(1988) 5th Int. Symp. on Very High Energy Cosmic-Ray Interactions, p. 180. , Lodz, 1988, Inst. of Physics, Univ. of Lodz, Poland(1990) Proc. 21st Int. Cosmic-Ray Conf., Adelaide, 1990, 8, p. 251. , Dept. Physics and Mathematical Physics, Univ. of Adelaide, Australia(1991) Izv. AN USSR No. 4, , to be publishedNikolsky, Shaulov, Cherdyntseva, (1990) FIAN preprint no. 140, , Lebedev Physical Institute, Moscow, [in Russian](1987) Proc. 20th Int. Cosmic-Ray Conf., Moscow, 1987, 5, p. 326. , Nauka, Mosco

Nuclear Interactions Of Super High Energy Cosmic-rays Observed In Mountain Emulsion Chambers

Here we present a summary of joint discussions on the results of three mountain experiments with large-scale emulsion chambers, at Pamir, Mt. Fuji and Chacaltaya. Observations cover gamma quanta, hadrons and their clusters (called "families"). The following topics are covered, concerning the characteristics of nuclear interactions the energy region 1014-1016 eV: (i) rapid dissipation seen in atmospheric diffusion of high-energy cosmic-rays; (ii) multiplicity and Pt increase in produced pi-mesons in the fragmentation region; (iii) existence of large-Pt jets, (iv) extremely hadron-rich family of the Centauro type; (v) exotic phenomena in the extremely high energy region beyond 1016 eV. © 1981.1911125(1977) Acta Univ. Lodz ser. II, (60)(1973) 13th Int. Cosmic-ray Conf., 3, p. 2228(1975) 14th Int. Cosmic-Ray Conf., 7, p. 2365(1979) AIP Conf. Proc. no. 49, p. 334(1979) 16th Int. Cosmic-ray Conf., 6, p. 344(1979) 16th Int. Cosmic-ray Conf., 7, p. 6816th Int. Cosmic-ray Conf. (1979) 16th Int. Cosmic-ray Conf., 7, p. 284(1979) 16th Int. Cosmic-ray Conf., 7, p. 294(1979) 16th Int. Cosmic-ray Conf., 13, p. 87(1979) 16th Int. Cosmic-ray Conf., 13, p. 92(1979) 16th Int. Cosmic-ray Conf., 13, p. 98(1979) AIP Conf. Proc. no. 49, p. 94(1979) AIP Conf. Proc. no. 49, p. 145(1979) AIP Conf. Proc. no. 49, p. 317(1979) 16th Int. Cosmic-ray Conf., 6, p. 350(1979) 16th Int. Cosmic-ray Conf., 6, p. 356(1979) 16th Int. Cosmic-ray Conf., 6, p. 362Nikolsky, Proc. 9th Int. High-energy Symp. (1978) CSSR, 21. , ToborMiyake, (1978) Proc. 19th Int. Conf. on High-energy physics, p. 433Vernov, (1977) Physica, 3, p. 1601Khristiansen, (1978) JETP Lett., 28, p. 124(1973) 13th Int. Cosmic-ray Conf., 3, p. 2219Izv. Acad. Nauk USSR, ser Phys. (1974) Izv. Acad. Nauk USSR, ser Phys., 38, p. 918(1975) 14th Int. Cosmic-ray Conf., 7, p. 2365(1979) 16th Int. Cosmic-ray Conf., 7, p. 68Dunaevsky, Urysson, Emelyanov, Shorin, Tashimov, (1975) FIAN preprint no. 150Dunaevsky, Urysson, Emelyanov, Shorin, Tashinov, (1979) Acta Univ. Lodz ser. II, (60), p. 199Ivanenko, Kanevskya, Roganova, (1978) JETP Lett., 40, p. 704Ivanenko, Kanevsky, Roganova, (1979) 16th Int. Cosmic-ray Conf., 7, p. 101Ivanenko, Kanevsky, Roganova, (1979) 16th Int. Cosmic-ray Conf., 7, p. 198Wrotniak, (1977) Acta Univ. Lodz ser. II, (60), p. 165Krys, Tomaszevski, Wrotniak, (1979) 16th Int. Cosmic-ray Conf., 7, p. 182Krys, Tomaszevski, Wrotniak, (1979) 16th Int. Cosmic-ray Conf., 7, p. 186Fomin, Kempa, Khristiansen, Levina, Piotrowska, Wdowczyk, (1977) 15th Int. Cosmic-ray Conf., 7, p. 248Fomin, Kempa, Khristiansen, Levina, Piotrowska, Wdowczyk, (1979) 16th Int. Cosmic-ray Conf., 13, p. 82Azimov, Mullazhanov, Yuldashbayev, (1979) 16th Int. Cosmic-ray Conf., 7, p. 262Azimov, Mullazhanov, Yuldashbayev, (1977) Acta Univ. Lodz ser. II, (60), p. 275Kasahara, Torri, Yuda, (1979) 16th Int. Cosmic-ray Conf., 13, p. 70Kasahara, Torii, Yuda, (1979) 16th Int. Cosmic-ray Conf., 13, p. 79Shibata, (1979) 16th Int. Cosmic-ray Conf., 7, p. 176H. Semba, T. Shibata and T. Tabuki, Suppl. Prog. Theor. Phys., to be publishedZhdanov, Roinishvilli, Smorodin, Tomaszevski, (1975) FIAN preprint no. 163Lattes, Fujimoto, Hasegawa, Hadronic interactions of high energy cosmic-ray observed by emulsion chambers (1980) Physics Reports, 65, p. 152Ellsworth, Gaisser, Yodh, (1981) Phys. Rev., 23 D, p. 764Baradzei, Smorodin, (1974) FIAN preprint nos. 103, 104Baradzei, Smorodin, (1977) Acta Univ. Lodz ser. II, (60), p. 51Zhdanov, (1980) FIAN preprint no. 140H. Semba, T. Shibata and T. Tabuki, Suppl. Prog. Theor. Phys., to be publishedShibata, (1980) Phys. Rev., 22 D, p. 100Slavatinsky, (1980) Proc. 7th European Symp. on Cosmic rays, , Leningrad, to be published(1979) AIP Conference Proc. no. 49, p. 145Azimov, Abduzhamilov, Chudakov, (1963) JETP (Sov. Phys.), 45, p. 40713th Int. Cosmic-ray Conf. (1973) 13th Int. Cosmic-ray Conf., 5, p. 326Acharya, Rao, Sivaprasad, Rao, (1979) 16th Int. Cosmic-ray Conf., 6, p. 289Ellsworth, Goodman, Yodh, Gaisser, Stanev, (1981) Phys. Rev., 23 D, p. 771Bariburina, Guseva, Denisova, (1980) Acta Univ. Lodz, 1, p. 9415th Int. Cosmic-ray Conf. (1977) 15th Int. Cosmic-ray Conf., 7, p. 184(1979) AIP Conf. Proc. no. 49, p. 33