Some consequences for LHC experiments from the results of cosmic ray investigations above the knee
A. A. Petrukhin
备注：
Contributed paper to XVI International Symposium on Very High Energy Cosmic Ray Interactions, ISVHECRI 2010, Batavia, IL, USA (28 June - 2 July 2010). 4 pages, 6 figures
Experimental data obtained in cosmic ray investigations at energies above the knee are discussed. All features observed at these energies starting from the knee, changes of mass composition and concluding with various types of unusual events are analysed in the framework of the new hadron interaction model producing blobs of quark gluon matter. Consequences for LHC experiments are considered.
The cosmic ray flux measured by the Telescope Array Low Energy Extension (TALE) exhibits three spectral features: the knee, the dip in the $10^{16}$ eV decade, and the second knee. Here the spectrum has been measured for the first time using fluorescence telescopes, which provide a calorimetric, model-independent result. The spectrum appears to be a rigidity-dependent cutoff sequence, where the knee is made by the hydrogen and helium portions of the composition, the dip comes from the reduction in composition from helium to metals, the rise to the second knee occurs due to intermediate range n…
The knee phenomenon of the cosmic ray spectrum, which plays an important role in studying the acceleration mechanism of cosmic rays, is still an unsolved mystery. We try to reconcile the knee spectra measured by ARGO-YBJ and Tibet-III. A simple broken power-law model fails to explain the experimental data. Therefore a modified broken power-law model with non-linear acceleration effects is adopted, which can describe the sharp knee structure. This model predicts that heavy elements dominate at the knee.
Primary energy spectrum of cosmic rays exhibits a knee at about $3$ PeV where a change in the spectral index occurs. Despite many efforts the origin of such a feature of the spectrum is not satisfactorily solved yet. Here it is proposed that the steepening of the spectrum beyond the knee may be a consequence of mass distribution of progenitor of cosmic ray source. The proposed speculative model can account all the major observed features about cosmic rays without invoking any fine tuning to match flux or spectra at any energy point. The prediction of the proposed model regarding primary compos…
All information about primary cosmic rays above the knee has been obtained from results of EAS investigations. At that, two alternative approaches exist: cosmophysical and nuclear physical. In the frame of the first one, all changes in measured EAS characteristics are explained by the changes in energy spectrum and mass composition of primary cosmic rays. In this paper, the second approach is considered, in frame of which corresponding changes in EAS parameters are explained by changes of interaction model above the knee. Some experimental possibilities of proof of the correctness of the nucle…
In this work we examine with the help of Monte Carlo simulation whether a consistent primary energy spectrum of cosmic rays emerges from both the experimentally observed total charged particles and muon size spectra of cosmic ray extensive air showers considering primary composition may or may not change beyond the knee of the energy spectrum. It is found that EAS-TOP observations consistently infer a knee in the primary energy spectrum provided the primary is pure unchanging iron whereas no consistent primary spectrum emerges from simultaneous use of the KASCADE observed total charged particl…
The nature of the knee in the all-particle spectrum of cosmic rays remains subject of much investigation, especially in the aftermath of recent measurements claiming the detection of a knee-like feature in the spectrum of the light component of cosmic rays at energy $\sim$700 TeV, at odds with the standard picture in which the knee in the all-particle spectrum is dominated by light cosmic rays. Here we investigate the implications of this and other scenarios in terms of the measured flux of atmospheric neutrinos. In particular we discuss the possibility that the spectrum of atmospheric neutrin…
Data from the NUCLEON space observatory give a strong indication of the existence of a new universal cosmic ray "knee", which is observed in all groups of nuclei, including heavy nuclei, near a magnetic rigidity of about 10\,TV. Universality means the same position of the knee in the magnetic rigidity scale for all groups of nuclei. The knee is observed by both methods of measurement of particles energy implemented in the NUCLEON observatory---the calorimetric method and the kinematic method KLEM. This new cosmic ray "knee" is probably connected with the limit of acceleration of cosmic rays by…
Joint constraint on the propagation origin of the cosmic-ray spectral knee from energy spectrum and anisotropy observations
State Key Laboratory of Particle Astrophyics, Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所粒子天体物理国家重点实验室）；School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）；School of Physical Science and Technology, Southwest Jiaotong University（西南交通大学物理科学与技术学院）；TIANFU Cosmic Ray Research Center（天府宇宙线研究中心）
The possibility of estimating the mass composition of primary cosmic rays above the knee of its energy spectrum through the study of high energy gamma rays, muons and neutrinos produced in the interactions of cosmic rays with the solar ambient matter and radiation has been explored. It is found that the theoretical fluxes of TeV gamma rays, muons and neutrinos from a region around $15^{o}$ of the Sun are sensitive to mass composition of cosmic rays in the PeV energy range. The experimental prospects for detection of such TeV gamma rays/neutrinos by future experiments are discussed.
The cosmic-ray (CR) knee and the compositions contain abundant information for probing the CR's origin, acceleration and propagation mechanisms, as well as the frontier of the fundamental physics. Realizing that major proposals toward the knee's shape can be divided into two categories: the rigidity-dependent (also Z-dependent) knee and the mass-dependent (also A-dependent) knee, where the former one relates to the acceleration or the propagation mechanisms, and the other one is often associated with the new physics, it is essential to precisely measure the individual compositions. Benefit fro…
X-ray Binaries: a potential dominant contributor to the cosmic ray spectral knee structure
Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；University of Chinese Academy of Sciences（中国科学院大学）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Southwest Jiaotong University（西南交通大学）；Tangshan University（唐山学院）；TIANFU Cosmic Ray Research Center（天府宇宙线研究中心）
This article presents a description of a cosmic rays diffusive propagationmodel of a close point-like flash lamp like source and an approximation ofexperimentally observed spectral irregularity with this model. We show thatthis spectral irregularity can be explained using the presented model andprovide the most probable characteristics of such a source as well as severalobserved and identified sources which can be candidates for this role.
The origin of the knee in cosmic ray spectrum remains to be an unsolved fundamental problem. There are various kinds of models which predict different break positions and the compositions of the knee. In this work, we suggest to use diffuse $γ$-rays and neutrinos as probes to test these models. Based on several typical types of the composition models, the diffuse $γ$-ray and neutrino spectra are calculated, which show distinctive cutoff behaviours at energies from tens of TeV to multi-PeV. The expected flux will be observable by the newly upgraded Tibet-AS$γ$+MD (muon detector) experiment as w…
A Multi-messenger Search for a Nearby Microquasar Contributor to the Cosmic Ray Knee
School of Physical Science and Technology, Southwest Jiaotong University（西南交通大学物理科学与技术学院）；State Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所粒子天体物理国家重点实验室）；University of Chinese Academy of Sciences（中国科学院大学）；TIANFU Cosmic Ray Research Center（天府宇宙线研究中心）
Investigations of the energy spectrum as well as the mass composition of cosmic rays in the energy range of PeVto EeV are important for understanding both, the origin of the galactic and the extragalactic cosmic rays. Recently, three modern experimental installations (KASCADE-Grande, IceTop, Tunka-133), dedicated to investigate this primary energy range, have published new results on the all-particle energy spectrum. In this short review these results are presented and the similarities and differences discussed. In addition, the effects of using different hadronic interaction models for interp…
Primary energy spectral models are tested in the energy range of 1-200 PeV using standardized extensive air shower responses from BASJE-MAS, Tibet, GAMMA and KASCADE scintillation shower arrays. Results point towards the two-component origin of observed cosmic ray energy spectra in the knee region (GAPS spectral model) consisting of a pulsar component superimposed upon rigidity-dependent power law diffuse galactic flux. The two-component energy spectral model accounts for both the sharp knee shower spectral phenomenon and observed irregularity of all-particle energy spectrum in the region of 5…
Cosmic rays around the knee are generally believed to be of galactic origin. Observations on their energy spectrum and chemical composition are important for understanding the acceleration and propagation of these cosmic rays. In addition, it is required to clarify the transition from galactic to extragalactic sources. In this paper, results of recent experiments measuring around the knee will be reviewed along with the detection techniques. The results on the all-particle energy spectrum and composition in the energy range of the knee up to the ankle will be discussed.
The mixed Hydrogen and Helium (H + He) spectrum with a clear steepening at $\sim 700$ TeV has been detected by ARGO-YBJ experiments. In this paper, we demonstrate that the observed H + He spectrum can be well reproduced with the model of cosmic rays escaping from the supernova remnants (SNRs) in our Galaxy. In this model, particles are accelerated in a SNR through a non-linear diffusive shock acceleration mechanism and three components of high energy light nuclei escaped from the SNR are considered. It should be noted that the proton spectrum observed by KASCADE can be also explained by this m…
We investigate the possibility that the cosmic ray (CR) knee is entirely explained by the energy-dependent CR leakage from the Milky Way. We test this hypothesis calculating the trajectories of individual CRs with energies between $E/Z=10^{14}$ eV and $10^{17}$ eV propagating them in the regular and turbulent Galactic magnetic field. We find a knee-like structure of the CR escape time $τ_{\rm esc}(E)$ around $E/Z={\rm few}\times 10^{15}$ eV for a coherence length $l_{\rm c} \simeq 2$ pc of the turbulent field, while the decrease of $τ_{\rm esc}(E)$ slows down around $E/Z\simeq 10^{16}$ eV in m…
We perform a fit to measurements of the cosmic ray spectrum and of the depth of shower maximum in the energy range between $10^{15}$~eV and $10^{18}$~eV. We consider a Galactic component that is a mixture of five representative nuclear species (H, He, N, Si and Fe), for which we adopt rigidity dependent broken power-law spectra, and we allow for an extragalactic component which becomes strongly suppressed for decreasing energies. The relative abundances of the Galactic components at $10^{15}$~eV are taken to be comparable to those determined by direct measurements at $10^{13}$~eV. The main fea…
Nonmonotonic change with energy of the mean logarithmic mass of cosmic rays in the knee region: the mechanism of formation of this feature and sources of particles
Microquasar Remnants as Pevatrons Illuminating the Galactic Cosmic Ray Knee
Key Laboratory of Particle Astrophysics and Experimental Physics Division and Computing Center, Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所粒子天体物理重点实验室及实验物理部计算中心）；TIANFU Cosmic Ray Research Center（天府宇宙线研究中心）；Department of Physics and Astronomy, University of Utah（犹他大学物理与天文系）
Spectral Softenings, Composition Bump, and Anisotropy Transition: A Consistent Picture of Cosmic-Ray Origin Below the Knee
Hebei Normal University（河北师范大学）；Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；University of Wisconsin–Madison（威斯康星大学麦迪逊分校）；TIANFU Cosmic Ray Research Center（天府宇宙线研究中心）；University of Chinese Academy of Sciences（中国科学院大学）
In a comprehensive model of Cosmic Rays (CRs) proposed a decade ago, the energies of the spectral "knees" of the various CR species were predicted to be proportional to mass, rather than charge. The model also predicts the knees to occur at an energy of two to four million times the particle's rest mass. Recent data allow one to verify this prediction, particularly for Fe and lighter-nuclei CRs. But the most stringent test involves the putative knee in the CR electron spectrum, since the mass ratio of electrons to protons (and nuclei) is so very different from their charge ratio(s). Very recen…
The diffuse $γ$-ray emission was measured up to $957$ TeV by the Tibet-AS$γ$ experiment recently. Assuming that it is produced by the hadronic interaction between cosmic ray nuclei and the interstellar medium, it requires that the cosmic ray nuclei should be accelerated well beyond PeV energies. Measurements of the cosmic ray spectra for different species show diverse results at present. The Tibet experiments showed that the spectrum of proton plus helium has an early knee below PeV. If this is correct, the diffuse $γ$-ray emission would suggest an additional component of Galactic cosmic rays …
More than fifty years after the discovery of the knee in the cosmic ray spectra, its physical origin remains a mystery. This is partly due to the ambiguity of the energy spectrum of individual composition. Recently, direct measurements from several balloon/satellite-borne detectors found significant spectral hardenings of cosmic ray nuclei at a few hundred GV rigidities. A joint modeling of the direct and indirect measurements of the cosmic ray spectra may help to understand the experimental systematics and probably the physics of the knee. In this work, we update the phenomenological "poly-go…
Oblique Shocks at Supernova Remnants in Massive Star Clusters: A Model for the Cosmic-Ray Knee Observed by LHAASO
Universidade Estadual de Londrina (UEL)（隆德里纳州立大学）；INAF-Osservatorio Astrofisico di Arcetri（意大利国家天体物理研究所阿切特里天文台）；Universidade Federal do Paraná (UFPR)（巴拉那联邦大学）；Universidade Federal do Espírito Santo (UFES)（圣埃斯皮里图联邦大学）；Universidade Tecnológica do Paraná (UTFPR)（巴拉那技术大学）；Universidade Federal da Integração Latino-Americana (UNILA)（拉丁美洲一体化联邦大学）
A new air-shower core-detector array (YAC : Yangbajing Air-shower Core-detector array) has been developed to measure the primary cosmic-ray composition at the "knee" energies in Tibet, China, focusing mainly on the light components. The prototype experiment (YAC-I) consisting of 16 detectors has been constructed and operated at Yangbajing (4300 m a.s.l.) in Tibet since May 2009. YAC-I is installed in the Tibet-III AS array and operates together. In this paper, we performed a Monte Carlo simulation to check the sensitivity of YAC-I+Tibet-III array to the cosmic-ray light component of cosmic ray…
Two kinds of Galactic source populations could explain the cosmic-ray observation up to the "knee" region
Beihang University（北京航空航天大学）；Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；University of Chinese Academy of Sciences（中国科学院大学）
