Author: Manabu Moritsu
Publisher: Springer
ISBN: 9811000123
Category : Science
Languages : en
Pages : 132
Book Description
This theses reports on an experimental search for an exotic hadron, Θ+(1540) pentaquark, which is a genuine exotic hadron with a five-quark system of uuddsbar. The results of this book support that the existence of Θ+ was strongly constrained. The Θ+ pentaquark was searched for via the π- p → K- X reaction using a beam momentum of 2.01 GeV/c at the J-PARC hadron experimental facility, taking advantage of high-statistics and high-resolution compared with previous experiments, some of which claimed the evidence of Θ+. In order to realize a good missing-mass resolution of 2 MeV, the beam spectrometer and superconducting kaon spectrometer were constructed. No clear peak was observed in the missing mass spectrum of the π- p → K- X reaction, and the upper limit of the production cross section was found to be less than 0.28 μb/sr at the 90% confidence level in a mass region of 1500–1560 MeV/c2. This upper limit is an order of magnitude smaller than that of the previous KEK experiment. Compared with a theoretical calculation using the effective Lagrangian approach, the decay width of Θ+ was evaluated. The upper limits on the decay width were estimated to be 0.36 and 1.9 MeV for the Θ+ spin-parity of 1/2+ and 1/2-, respectively. These are quite small for a width of ordinary hadron resonances, and the existence of Θ+ was strongly constrained and is doubtful.
Search for the Pentaquark Θ+ via the π−p → K−X Reaction at J-PARC
Author: Manabu Moritsu
Publisher: Springer
ISBN: 9811000123
Category : Science
Languages : en
Pages : 132
Book Description
This theses reports on an experimental search for an exotic hadron, Θ+(1540) pentaquark, which is a genuine exotic hadron with a five-quark system of uuddsbar. The results of this book support that the existence of Θ+ was strongly constrained. The Θ+ pentaquark was searched for via the π- p → K- X reaction using a beam momentum of 2.01 GeV/c at the J-PARC hadron experimental facility, taking advantage of high-statistics and high-resolution compared with previous experiments, some of which claimed the evidence of Θ+. In order to realize a good missing-mass resolution of 2 MeV, the beam spectrometer and superconducting kaon spectrometer were constructed. No clear peak was observed in the missing mass spectrum of the π- p → K- X reaction, and the upper limit of the production cross section was found to be less than 0.28 μb/sr at the 90% confidence level in a mass region of 1500–1560 MeV/c2. This upper limit is an order of magnitude smaller than that of the previous KEK experiment. Compared with a theoretical calculation using the effective Lagrangian approach, the decay width of Θ+ was evaluated. The upper limits on the decay width were estimated to be 0.36 and 1.9 MeV for the Θ+ spin-parity of 1/2+ and 1/2-, respectively. These are quite small for a width of ordinary hadron resonances, and the existence of Θ+ was strongly constrained and is doubtful.
Publisher: Springer
ISBN: 9811000123
Category : Science
Languages : en
Pages : 132
Book Description
This theses reports on an experimental search for an exotic hadron, Θ+(1540) pentaquark, which is a genuine exotic hadron with a five-quark system of uuddsbar. The results of this book support that the existence of Θ+ was strongly constrained. The Θ+ pentaquark was searched for via the π- p → K- X reaction using a beam momentum of 2.01 GeV/c at the J-PARC hadron experimental facility, taking advantage of high-statistics and high-resolution compared with previous experiments, some of which claimed the evidence of Θ+. In order to realize a good missing-mass resolution of 2 MeV, the beam spectrometer and superconducting kaon spectrometer were constructed. No clear peak was observed in the missing mass spectrum of the π- p → K- X reaction, and the upper limit of the production cross section was found to be less than 0.28 μb/sr at the 90% confidence level in a mass region of 1500–1560 MeV/c2. This upper limit is an order of magnitude smaller than that of the previous KEK experiment. Compared with a theoretical calculation using the effective Lagrangian approach, the decay width of Θ+ was evaluated. The upper limits on the decay width were estimated to be 0.36 and 1.9 MeV for the Θ+ spin-parity of 1/2+ and 1/2-, respectively. These are quite small for a width of ordinary hadron resonances, and the existence of Θ+ was strongly constrained and is doubtful.
Understanding the Origin of Matter
Author: David Blaschke
Publisher:
ISBN: 9788303095497
Category : Electronic books
Languages : en
Pages : 0
Book Description
This book aims at providing a solid basis for the education of the next generation of researchers in hot, dense QCD (Quantum ChromoDynamics) matter. This is a rapidly growing field at the interface of the smallest, i.e. subnuclear physics, and the largest scales, namely astrophysics and cosmology. The extensive lectures presented here are based on the material used at the training school of the European COST action THOR (Theory of hot matter in relativistic heavy-ion collisions). The book is divided in three parts covering ultrarelativistic heavy-ion collisions, several aspects related to QCD, and simulations of QCD and heavy-ion collisions. The scientific tools and methods discussed provide graduate students with the necessary skills to understand the structure of matter under extreme conditions of high densities, temperatures, and strong fields in the collapse of massive stars or a few microseconds after the big bang. In addition to the theory, the set of lectures presents hands-on material that includes an introduction to simulation programs for heavy-ion collisions, equations of state, and transport properties.
Publisher:
ISBN: 9788303095497
Category : Electronic books
Languages : en
Pages : 0
Book Description
This book aims at providing a solid basis for the education of the next generation of researchers in hot, dense QCD (Quantum ChromoDynamics) matter. This is a rapidly growing field at the interface of the smallest, i.e. subnuclear physics, and the largest scales, namely astrophysics and cosmology. The extensive lectures presented here are based on the material used at the training school of the European COST action THOR (Theory of hot matter in relativistic heavy-ion collisions). The book is divided in three parts covering ultrarelativistic heavy-ion collisions, several aspects related to QCD, and simulations of QCD and heavy-ion collisions. The scientific tools and methods discussed provide graduate students with the necessary skills to understand the structure of matter under extreme conditions of high densities, temperatures, and strong fields in the collapse of massive stars or a few microseconds after the big bang. In addition to the theory, the set of lectures presents hands-on material that includes an introduction to simulation programs for heavy-ion collisions, equations of state, and transport properties.