TY - JOUR

T1 - Monochromatization of $e^+e^-$ colliders with a large crossing angle

AU - Telnov, V. I.

PY - 2024

Y1 - 2024

N2 - The relative center-of-mass energy spread at $e^+e^-$ colliders is about 10^{-3}, which is much larger than the widths of narrow resonances produced in the s-channel in $e^+e^-$ collisions. This circumstance greatly lowers the resonance production rates of J/Psi, Upsilon(1S), Upsilon(2S), Upsilon(3S) and makes it extremely difficult to observe resonance production of the Higgs boson. Thus, a significant reduction of the center-of-mass energy spread would open up great opportunities in the search for new physics in rare decays of narrow resonances, the search for new narrow states with small $\Gamma_{e^+e^-}$, the study of true muonium and tauonium, etc. The existing monochromatization scheme is only suitable for head-on collisions, while $e^+e^-$ colliders with crossing angles (the so-called Crab Waist collision scheme) can provide significantly higher luminosity due to reduced collision effects. In this paper, we propose a new monochromatization method for colliders with a large crossing angle. The contribution of the beam energy spread to the spread of the center-of-mass energy is canceled by introducing an appropriate energy-angle correlation at the interaction point; $\sigma_W/W \sim (3-5)10^{-6}$ appears possible. Limitations of the proposed method are also considered.

AB - The relative center-of-mass energy spread at $e^+e^-$ colliders is about 10^{-3}, which is much larger than the widths of narrow resonances produced in the s-channel in $e^+e^-$ collisions. This circumstance greatly lowers the resonance production rates of J/Psi, Upsilon(1S), Upsilon(2S), Upsilon(3S) and makes it extremely difficult to observe resonance production of the Higgs boson. Thus, a significant reduction of the center-of-mass energy spread would open up great opportunities in the search for new physics in rare decays of narrow resonances, the search for new narrow states with small $\Gamma_{e^+e^-}$, the study of true muonium and tauonium, etc. The existing monochromatization scheme is only suitable for head-on collisions, while $e^+e^-$ colliders with crossing angles (the so-called Crab Waist collision scheme) can provide significantly higher luminosity due to reduced collision effects. In this paper, we propose a new monochromatization method for colliders with a large crossing angle. The contribution of the beam energy spread to the spread of the center-of-mass energy is canceled by introducing an appropriate energy-angle correlation at the interaction point; $\sigma_W/W \sim (3-5)10^{-6}$ appears possible. Limitations of the proposed method are also considered.

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85206341288&origin=inward&txGid=972ba1dcb680fcb0f77737f33573a972

UR - http://arxiv.org/abs/2008.13668

UR - https://www.mendeley.com/catalogue/73d100a6-7022-3db8-8790-10cd2f417708/

U2 - 10.1142/S0217732324400029

DO - 10.1142/S0217732324400029

M3 - Article

JO - Modern Physics Letters A

JF - Modern Physics Letters A

SN - 0217-7323

M1 - 2440002

ER -