IPAC2019 - Classification: MC1: Circular and Linear Colliders / A02 Lepton Colliders

Paper	Title	Page
MOZPLS1	Particle Physics at the High Energy Frontier with the Next Electron-Positron Collider
	H. Aihara University of Tokyo, Tokyo, Japan
	After discovering the Higgs boson and the recent studies at the Large Hadron Collider at CERN, high precision measurements at a future electron-positron collider are proposed as the best way to further test the validity of the Standard Model. In particular, the complete knowledge of the initial state and the low background environment of an electron-positron collider allows for superior event reconstruction, enabling detailed measurements of the properties of the Higgs boson. These measurements will allow us to discriminate among the new physics models proposed to resolve several inconsistencies in the Standard Model, thereby improving our understanding of particle physics at the most fundamental scale and paving the way for the future of the field. The physics programme of a future electron-positron collider will be presented outlining the relative merits of the linear and circular collider projects currently under consideration in the community.
	Slides MOZPLS1 [9.287 MB]
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MOPGW068	Crosstalk of Beam-Beam Effect and Longitudinal Impedance at CEPC	247
	Y. Zhang, N. Wang, C.H. Yu IHEP, Beijing, People’s Republic of China C.T. Lin University of Chinese Academy of Sciences, Beijing, People’s Republic of China
	Funding: Project 11775238 supported by NSFC In conventional e⁺e⁻ storage ring colliders, we only use lengthend bunch length in beam-beam simulation instead of considering impedance directly. It is no problem since the longitudinal dynamics is not sensitive to beam-beam interaction. But it is different since the bunch will also be lengthend during beam-beam interaction by beamstrahlung effect. It is very natural and more self-consistent to consider the longitudinal impedance in the beam-beam simulation. The simulation shows that the working point region of stable collision is slightly shifted by the longitudinal impedance. It is found that the vertical coherent oscillation may decreases the beam-beam limit with impedance at some working point.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW068
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPMP003	Positron Source for FCC-ee	424
	I. Chaikovska, R. Chehab, A. Faus-Golfe, Y. Han LAL, Orsay, France A. Apyan ANSL, Yerevan, Armenia Y. Enomoto, K. Furukawa, T. Kamitani, F. Miyahara, M. Satoh, Y. Seimiya, T. Suwada KEK, Ibaraki, Japan P.V. Martyshkin BINP SB RAS, Novosibirsk, Russia S. Ogur, K. Oide, Y. Papaphilippou, L. Rinolfi, P. Sievers, F. Zimmermann CERN, Geneva, Switzerland
	The FCC-ee is a high-luminosity, high-precision circular collider to be constructed in a new 100 km tunnel in the Geneva area. The physics case is well established and the FCC-ee operation is foreseen at 91 GeV (Z-pole), 160 GeV (W pair production threshold), 240 GeV (Higgs resonance) and 365 GeV (t-tbar threshold). Due to the large 6D production emittance and important thermal load in the production target, the positron injector, in particular the positron source, is one of the key elements of the FCC-ee, requiring special attention. To ensure high reliability of the positron source, conventional and hybrid targets are currently under study. The final choice of the positron target will be made based on the estimated performances. In this framework, we present a preliminary design of the FCC-ee positron source, with detailed simulation studies of positron production, capture and primary acceleration.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP003
About •	paper received ※ 03 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPMP006	Magnetic Measurement With Single Stretched Wire Method on SuperKEKB Final Focus Quadrupoles	432
	Y. Arimoto, K. Egawa, T. Kawamoto, M. Masuzawa, Y. Ohsawa, N. Ohuchi, R. Ueki, X. Wang, H. Yamaoka, Z.G. Zong KEK, Ibaraki, Japan J. DiMarco, J.M. Nogiec, G. Velev Fermilab, Batavia, Illinois, USA
	Superconducting-final-focus-quadrupole magnet system (QCS) were installed on an interaction region (IR) of SuperKEKB on Feb. 2017. The QCS consists of eight quadrupole magnets and four compensation solenoids; these magnets are contained in the two cryostats and are installed into Belle II detector which generates a solenoid field of 1.5 T. We determined the quadrupole centers with respect to accelerator beam lines with a single stretched wire (SSW) method. Here the results of the magnetic measurement with SSW are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP006
About •	paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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MOPMP012	Concepts of Longitudinally Polarized Electron and Positron Colliding Beams in the Circular Electron Positron Collider	445
	Z. Duan, J. Gao, X.P. Li, D. Wang, Y. Wang, W.H. Xia, Q.J. Xu, C.H. Yu, Y. Zhang IHEP, Beijing, People’s Republic of China
	Funding: Work supported by National Key Research and Development Program of China (No.2018YFA0404300). This paper reports some preliminary study into the imple- mentation of longitudinally polarized e⁺/e⁻ colliding beams in the Circular Electron Positron Collider, at a center of mass energy of 91 GeV as a Z factory and energies beyond.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP012
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPMP035	Effect of Emittance Constraints on Monochromatization at the Future Circular e⁺e⁻ Collider	516
	M.A. Valdivia García, F. Zimmermann CERN, Meyrin, Switzerland
	Direct s-channel Higgs production in e+e− collisions is of interest if the collision energy spread can be comparable to the natural width of the standard model Higgs boson. At the Future Circular e⁺e⁻ Collider (FCC-ee), a monochromatization scheme could be employed in order to reduce the collision energy spread to the target value. This may be achieved by introducing a non-zero horizontal dispersion of opposite sign for the two colliding beams at the interaction point. In this case, the beamstrahlung increases the horizontal emittance in addition to energy spread and bunch length. The vertical emittance could either be tuned to a certain minimum value, possibly limited by the diagnostics resolution, or it could scale linearly with the horizontal emittance. For the FCC-ee at 62.5 GeV beam energy, we optimize the IP optics and beam parameters, considering these two different assumptions for the vertical emittance. We derive the maximum achievable luminosity as a function of collision energy spread for either case.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP035
About •	paper received ※ 16 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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WEYYPLM1	Status of Early SuperKEKB Phase-3 Commissioning	2255
	A. Morita KEK, Ibaraki, Japan
	SuperKEKB is an asymmetric energy electron-positron collider for B-meson physics experiment. The beam collision with 3mm vertical beta function at the interaction point is confirmed during prior beam commissioning until July 2018. The next beam commissioning with the inner silicon vertex detectors so called "phase-3 commissioning" will start in March 2019. In the early part of next phase-3 commissioning, we plan to try the collision operation with over 1A stored beam current in order to exceed 1 x 10³⁴ cm^-2 s^-1 luminosity. We will report the preliminary results of the early stage of the SuperKEKB phase-3 commissioning.
	Slides WEYYPLM1 [2.570 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEYYPLM1
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

MOZPLS1

Particle Physics at the High Energy Frontier with the Next Electron-Positron Collider

H. Aihara
University of Tokyo, Tokyo, Japan

After discovering the Higgs boson and the recent studies at the Large Hadron Collider at CERN, high precision measurements at a future electron-positron collider are proposed as the best way to further test the validity of the Standard Model. In particular, the complete knowledge of the initial state and the low background environment of an electron-positron collider allows for superior event reconstruction, enabling detailed measurements of the properties of the Higgs boson. These measurements will allow us to discriminate among the new physics models proposed to resolve several inconsistencies in the Standard Model, thereby improving our understanding of particle physics at the most fundamental scale and paving the way for the future of the field. The physics programme of a future electron-positron collider will be presented outlining the relative merits of the linear and circular collider projects currently under consideration in the community.

Slides MOZPLS1 [9.287 MB]

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW068

Crosstalk of Beam-Beam Effect and Longitudinal Impedance at CEPC

247

Y. Zhang, N. Wang, C.H. Yu
IHEP, Beijing, People’s Republic of China
C.T. Lin
University of Chinese Academy of Sciences, Beijing, People’s Republic of China

Funding: Project 11775238 supported by NSFC
In conventional e⁺e⁻ storage ring colliders, we only use lengthend bunch length in beam-beam simulation instead of considering impedance directly. It is no problem since the longitudinal dynamics is not sensitive to beam-beam interaction. But it is different since the bunch will also be lengthend during beam-beam interaction by beamstrahlung effect. It is very natural and more self-consistent to consider the longitudinal impedance in the beam-beam simulation. The simulation shows that the working point region of stable collision is slightly shifted by the longitudinal impedance. It is found that the vertical coherent oscillation may decreases the beam-beam limit with impedance at some working point.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW068

About •

paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP003

Positron Source for FCC-ee

424

I. Chaikovska, R. Chehab, A. Faus-Golfe, Y. Han
LAL, Orsay, France
A. Apyan
ANSL, Yerevan, Armenia
Y. Enomoto, K. Furukawa, T. Kamitani, F. Miyahara, M. Satoh, Y. Seimiya, T. Suwada
KEK, Ibaraki, Japan
P.V. Martyshkin
BINP SB RAS, Novosibirsk, Russia
S. Ogur, K. Oide, Y. Papaphilippou, L. Rinolfi, P. Sievers, F. Zimmermann
CERN, Geneva, Switzerland

The FCC-ee is a high-luminosity, high-precision circular collider to be constructed in a new 100 km tunnel in the Geneva area. The physics case is well established and the FCC-ee operation is foreseen at 91 GeV (Z-pole), 160 GeV (W pair production threshold), 240 GeV (Higgs resonance) and 365 GeV (t-tbar threshold). Due to the large 6D production emittance and important thermal load in the production target, the positron injector, in particular the positron source, is one of the key elements of the FCC-ee, requiring special attention. To ensure high reliability of the positron source, conventional and hybrid targets are currently under study. The final choice of the positron target will be made based on the estimated performances. In this framework, we present a preliminary design of the FCC-ee positron source, with detailed simulation studies of positron production, capture and primary acceleration.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP003

About •

paper received ※ 03 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP006

Magnetic Measurement With Single Stretched Wire Method on SuperKEKB Final Focus Quadrupoles

432

Y. Arimoto, K. Egawa, T. Kawamoto, M. Masuzawa, Y. Ohsawa, N. Ohuchi, R. Ueki, X. Wang, H. Yamaoka, Z.G. Zong
KEK, Ibaraki, Japan
J. DiMarco, J.M. Nogiec, G. Velev
Fermilab, Batavia, Illinois, USA

Superconducting-final-focus-quadrupole magnet system (QCS) were installed on an interaction region (IR) of SuperKEKB on Feb. 2017. The QCS consists of eight quadrupole magnets and four compensation solenoids; these magnets are contained in the two cryostats and are installed into Belle II detector which generates a solenoid field of 1.5 T. We determined the quadrupole centers with respect to accelerator beam lines with a single stretched wire (SSW) method. Here the results of the magnetic measurement with SSW are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP006

About •

paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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MOPMP012

Concepts of Longitudinally Polarized Electron and Positron Colliding Beams in the Circular Electron Positron Collider

445

Z. Duan, J. Gao, X.P. Li, D. Wang, Y. Wang, W.H. Xia, Q.J. Xu, C.H. Yu, Y. Zhang
IHEP, Beijing, People’s Republic of China

Funding: Work supported by National Key Research and Development Program of China (No.2018YFA0404300).
This paper reports some preliminary study into the imple- mentation of longitudinally polarized e⁺/e⁻ colliding beams in the Circular Electron Positron Collider, at a center of mass energy of 91 GeV as a Z factory and energies beyond.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP012

About •

paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP035

Effect of Emittance Constraints on Monochromatization at the Future Circular e⁺e⁻ Collider

516

M.A. Valdivia García, F. Zimmermann
CERN, Meyrin, Switzerland

Direct s-channel Higgs production in e+e− collisions is of interest if the collision energy spread can be comparable to the natural width of the standard model Higgs boson. At the Future Circular e⁺e⁻ Collider (FCC-ee), a monochromatization scheme could be employed in order to reduce the collision energy spread to the target value. This may be achieved by introducing a non-zero horizontal dispersion of opposite sign for the two colliding beams at the interaction point. In this case, the beamstrahlung increases the horizontal emittance in addition to energy spread and bunch length. The vertical emittance could either be tuned to a certain minimum value, possibly limited by the diagnostics resolution, or it could scale linearly with the horizontal emittance. For the FCC-ee at 62.5 GeV beam energy, we optimize the IP optics and beam parameters, considering these two different assumptions for the vertical emittance. We derive the maximum achievable luminosity as a function of collision energy spread for either case.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP035

About •

paper received ※ 16 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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WEYYPLM1

Status of Early SuperKEKB Phase-3 Commissioning

2255

A. Morita
KEK, Ibaraki, Japan

SuperKEKB is an asymmetric energy electron-positron collider for B-meson physics experiment. The beam collision with 3mm vertical beta function at the interaction point is confirmed during prior beam commissioning until July 2018. The next beam commissioning with the inner silicon vertex detectors so called "phase-3 commissioning" will start in March 2019. In the early part of next phase-3 commissioning, we plan to try the collision operation with over 1A stored beam current in order to exceed 1 x 10³⁴ cm^-2 s^-1 luminosity. We will report the preliminary results of the early stage of the SuperKEKB phase-3 commissioning.

Slides WEYYPLM1 [2.570 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEYYPLM1

About •

paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

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