共查询到20条相似文献,搜索用时 31 毫秒
1.
Klaus Mönig 《Pramana》2007,69(6):1181-1184
The photon collider is an option at the ILC. In this note detector issues are discussed that are relevant for the change from
the e
+
e
− mode of the ILC to the γγ mode.
相似文献
2.
V. I. Telnov 《Pramana》2007,69(6):1177-1179
One of the interaction regions at the linear colliders should be compatible both with e
+
e
− and γγ, γe modes of operation. In this paper, the differences in requirements and possible design solutions are discussed.
相似文献
3.
We examine the sensitivity of eγ colliders (based on e
+
e
− linear colliders of c.m. energy 500 GeV) to the anomalous couplings of the Higgs to W-boson via the process e
−
γ → νWH. This has the advantage over e
+
e
− collider in being able to dissociate WWH vertex from ZZH. We are able to construct several dynamical variables which may be used to constrain the various couplings in the WWH vertex.
相似文献
4.
We have performed a detailed study of the power losses in the post-collision extraction line of a TeV e
+
e
− collider with a crossing angle of 20 mrad at the interaction point. Five cases were considered: four luminosity configurations
for ILC and one for CLIC. For all of them, the strong beam-beam effects at the interaction point lead to an emittance growth
for the outgoing beam, as well as to the production of beamstrahlung photons and e
+
e
− coherent pairs. The power losses along the extraction line, which are due to energy deposition by a fraction of the disrupted
beam, of the beamstrahlung photons and of the coherent pairs, were estimated in the case of ideal collisions, as well as with
a vertical position or angular offset at the interaction point.
相似文献
5.
Gautam Bhattacharyya 《Pramana》2007,69(5):903-907
We consider the UED scenario and study the detectability of the first KK electron-positron pair at the ILC. A few hundred
GeV KK electron decays into a nearly degenerate KK photon, which carries away missing energy, and the standard electron. The
mass splitting between the KK electron and KK photon is controlled by the bulk-and brane-induced radiative corrections. We
look for the signal event e
+
e
− + large missing energy for √s = 1 TeV and observe that with a few hundred fb−1 luminosity the signal can be deciphered from the standard model background. We briefly outline how the UED signals may be
distinguished from the supersymmetric signals.
This talk is based on a work the author did with Paramita Dey, Anirban Kundu and Amitava Raychaudhuri [1]. 相似文献
6.
S. I. Eidelman G. V. Fedotovich E. A. Kuraev A. L. Sibidanov 《The European Physical Journal C - Particles and Fields》2011,71(6):1597
Monte-Carlo generator with photon jets radiation in collinear regions for the process e
+
e
−→γγ is described in detail. Radiative corrections in the first order of α are treated exactly. Large leading logarithmic corrections coming from collinear regions are taken into account in all orders
of α by applying the Structure Function approach. Theoretical precision of the cross section with radiative corrections is estimated
to be 0.2%. This process is considered as an additional tool to measure luminosity in forthcoming experiments with the CMD-3
detector at the e
+
e
− collider VEPP-2000. 相似文献
7.
Saurabh D Rindani 《Pramana》2006,67(4):579-596
The talk described the prospects of studying standard model parameters as well as scenarios beyond the standard model, like
the minimal supersymmetric standard model, theories with extra dimensions and theories with extra neutral gauge bosons, at
a future linear e
+
e
− collider. 相似文献
8.
S. Heinemeyer 《Pramana》2007,69(5):727-733
The international linear e
+
e
− collider (ILC) could go into operation in the second half of the upcoming decade. Experimental analyses and theory calculations
for the physics at the ILC are currently performed. We review recent progress, as presented at the LCWS06 in Bangalore, India,
in the fields of Higgs boson physics and top/QCD. Also the area of loop calculations, necessary to achieve the required theory
precision, is included.
相似文献
9.
K. Mawatari B. Oexl Y. Takaesu 《The European Physical Journal C - Particles and Fields》2011,71(11):1783
Light gravitino productions in association with a neutralino (selectron) in e
+
e
− (e
−
γ) collisions are restudied in a scenario that the lightest supersymmetric particle is a gravitino and the produced neutralino
(selectron) promptly decays into a photon (electron) and a gravitino. We explicitly give the helicity amplitudes for the production
processes by using the effective goldstino interaction Lagrangian, and present the cross sections with different collision
energies and mass spectra. We also examine selection efficiencies by kinematical cuts and beam polarizations for the signal
and background processes, and show that the energy and angular distributions of the photon (electron) can explore the mass
of the t-channel exchange particle as well as the mass of the decaying particle at a future e
+
e
− (e
−
γ) collider. 相似文献
10.
Sunanda Banerjee 《Pramana》2000,55(1-2):85-100
Several studies have been made to the hadronic final states in e
+
e
− collisions at LEP. Studies of the annihilation process at LEP2 have given rise to results on jet rate, event shape, heavy
flavour production, inclusive momentum spectra, Bose-Einstein correlation and colour reconnection effects. Event shape studies
have given rise to accurate determination of the strong coupling constant α
s using O (α
s
2
) with resummed leading and next-to-leading log calculation and also with power law corrections. Studies of 2-photon processes
have yielded results on γγ cross-section, heavy flavour production, photon structure function and γ*γ* scattering. 相似文献
11.
We review high-energy scattering processes that are sensitive to the hadronic structure of the photon, describing theoretical
predictions as well as recent experimental results. These processes include deep-inelastic electron-photon scattering ate
+
e
− colliders; and the production of jets, heavy quarks and isolated photons in the collision of real photons ate
+
e
− colliders, as well as in photon-photon collisions atep colliders. We also comment on minijet based calculations of totalγp andγγ cross-sections, and discuss the possibility that future lineare
+
e
− colliders might produce very large photon fluxes due to the beamstrahlung phenomenon; in the most extreme cases, we predict
more than one hadronicγγ event to occur at every bunch crossing. 相似文献
12.
Fawzi Boudjema 《Pramana》1998,51(1-2):249-271
The physics at the plannede
+
e
- colliders is discussed around three main topics corresponding to different manifestations of symmetry breaking:W physics in the no Higgs scenario, studies of the properties of the Higgs and precision tests of SUSY. A comparison with the
LHC is made for all these cases. The γγ mode of the linear collider will also be reviewed. 相似文献
13.
M. N. Achasov A. V. Bozhenok A. D. Bukin D. A. Bukin S. V. Burdin T. V. Dimova S. I. Dolinsky V. P. Druzhinin M. S. Dubrovin I. A. Gaponenko V. B. Golubev V. N. Ivanchenko A. A. Korol S. V. Koshuba A. P. Lysenko E. V. Pakhtusova V. V. Shary Yu. M. Shatunov V. A. Sidorov Z. K. Silagadze S. I. Serednyakov A. A. Valishev Yu. V. Usov 《JETP Letters》1998,67(10):777-780
Results from the Spherical Nonmagnetic Detector (SND) on Δ(1232) isobar electroproduction in the collisions of beam electrons
(positrons) and residual gas nuclei in the VEPP-2M e
+
e
− collider are presented. On the basis of the data obtained the expected counting rate of this process in future high-luminosity
e
+
e
− colliders (φ, c-τ, and b factories) is estimated.
Pis’ma Zh. éksp. Teor. Fiz. 67, No. 10, 737–740 (25 May 1998)
Published in English in the original Russian journal. Edited by Steve Torstveit. 相似文献
14.
D. Habs B. M. Hegelich J. Schreiber P. G. Thirolf 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,55(2):253-264
The use is suggested of a laser-accelerated dense electron sheet with
an energy of (E=[(g)\tilde] mc2E=\tilde{\gamma} mc^2) as a relativistic mirror to reflect coherently a second
laser with photon energy ħω, generating by the Doppler boost
high-energy γ photons with $
\hbar \omega ' = 4\tilde \gamma ^2 \hbar \omega
$
\hbar \omega ' = 4\tilde \gamma ^2 \hbar \omega
and
short duration [A. Einstein, Annalen der Physik 17, 891 (1905); D. Habs et al., Appl. Phys. B 93, 349 (2008)]. Two of these counter-propagating
γ beams are focused by the parabolically shaped electron sheets into the
interaction region with small, close to diffraction-limited, spot size.
Comparing the new nγ-mγ collider with former proposed
γγ collider schemes we achieve the conversion of many
photon-pairs in a small space-time volume to matter-antimatter particles,
while in the other discussed setups only two isolated, much more
high-energetic photons will be converted, reaching in the
new approach much higher energy densities and temperatures.
With a γ-field strength somewhat below the Schwinger limit we can
reach this complete conversion of the γ bunch energy into
e+e- or quark-antiquark q[`(q)]q\bar{q}-plasmas.
For a Bose-Einstein condensate (BEC) [A. Einstein, Physikalisch-mathematische Klasse (Berlin) 22, 261 (1924); A. Einstein, Physikalisch-mathematische Klasse (Berlin) 22, 3 (1925); A. Griffin, D.W. Snoke, S. Stringari, Bose-Einstein Condensation (Cambridge University Press, 1995)] final state or for the Cooper pair ground state at higher densities [A.J. Leggett, Quantum Liquids, Oxford Graduate Texts (Oxford University Press, 2006)] the strong induced transition
into this coherent state is of special interest for single-cycle γ
pulses. Due to annihilation these cold coherent states are very
short-lived. For γ beams with photon energies
of 1–10 keV the rather cold e+e--plasma or
e+e--BEC expands to a cold dense aggregate of positronium (Ps)
atoms, where the production of Ps molecules is discussed.
For photon energies of 1–10 MeV we discuss the production of
a cold induced π0-BEC followed by the formation of molecules.
For the direct population of higher q[`(q)]q\bar{q} densities we can study
condensates of color-neutral mesons with enhanced population.
For a γγ collider with several-cycle laser pulses
the following cycles heat up the fermion-antifermion
f[`(f)]f\bar{f} system to a certain temperature.
Thus we can reach high energy densities and temperatures of an e+e-γ
plasma, where the production of hadrons in general or the quark-gluon
phase transition can be observed. Within the long-term goal of very
high photon energies of about 1 GeV in the nγ-mγ-collider,
even the electro-weak phase transition or SUSY phase transition
could be reached. 相似文献
15.
The minimal supersymmetric extension of the standard model (MSSM) predicts the existence of new charged and neutral Higgs
bosons. The pair creation of these new particles at the multi-TeV e
+
e
− compact linear collider (CLIC), followed by decays into standard model particles, were simulated along with the corresponding
background. High-energy beam-beam effects such as ISR, beamstrahlung and hadronic background were included. We have investigated
the possibility of using the ratio between the number of events found in various decay channels to determine the MSSM parameter
tan β and we have derived the corresponding statistical error from the uncertainties on the measured cross-sections and Higgs boson
masses.
相似文献
16.
J. Kovermann A. Stahl A. A. Mikhailichenko D. Scott G. A. Moortgat-Pick V. Gharibyan P. Pahl R. Pöschl K. P. Schüler K. Laihem S. Riemann A. Schälicke R. Dollan H. Kolanoski T. Lohse T. Schweizer K. T. McDonald Y. Batygin V. Bharadwaj G. Bower F. -J. Decker C. Hast R. Iverson J. C. Sheppard Z. Szalata D. Walz A. Weidemann G. Alexander E. Reinherz-Aronis S. Berridge W. Bugg Y. Efrimenko 《Pramana》2007,69(6):1165-1169
A longitudinal polarized positron beam is foreseen for the international linear collider (ILC). A proof-of-principle experiment
has been performed in the final focus test beam at SLAC to demonstrate the production of polarized positrons for implementation
at the ILC. The E166 experiment uses a 1 m long helical undulator in a 46.6 GeV electron beam to produce a few MeV photons
with a high degree of circular polarization. These photons are then converted in a thin target to generate longitudinally
polarized e
+ and e
−. The positron polarization is measured using a Compton transmission polarimeter. The data analysis has shown asymmetries
in the expected vicinity of 3.4% and ∼1% for photons and positrons respectively and the expected positron longitudinal polarization
is covering a range from 50% to 90%.
相似文献
17.
The minimal supersymmetric extension of the standard model (MSSM) predicts the existence of new charged and neutral Higgs
bosons. The pair creation of these new particles at the multi-TeV e
+
e
− compact linear collider (CLIC), followed by decays into standard model particles, were simulated along with the corresponding
background. High-energy beam-beam effects such as ISR, beamstrahlung and hadronic background were included. We have investigated
the possibility of using the ratio between the number of events found in various decay channels to determine the MSSM parameter
tan β and we have derived the corresponding statistical error from the uncertainties on the measured cross-sections and Higgs boson
masses.
相似文献
18.
The DAΦNE e
+
e
− collider, the Φ-factory currently operating at the INFN National Laboratories of Frascati (Italy), is the unconventional
playground where the FINUDA Collaboration is successfully carrying on its hypernuclear study program. In view of a possible
machine luminosity upgrade, it has been proposed to add to the present FINUDA spectrometer the γ-ray detection capability. The combined exploitation of the excellent High Purity Germanium detector energy resolution and
of the FINUDA performances will allow the construction of a powerful and really complete experimental setup dedicated to hypernuclear
physics.
for the HyperGamma Collaboration 相似文献
19.
Sudhansu S. Biswal Debajyoti Choudhury Rohini M. Godbole Ritesh K. Singh 《Pramana》2007,69(5):777-782
We examine, in a model independent way, the sensitivity of a linear collider to the couplings of a light Higgs boson to a
pair of gauge bosons, including the possibility of CP violation. We construct several observables that probe the various possible
anomalous couplings. For an intermediate mass Higgs, a collider operating at a center of mass energy of 500 GeV and with an
integrated luminosity of 500 fb−1 is shown to be able to constrain the ZZH vertex at the few per cent level, with even higher sensitivity for some of the couplings. However, lack of sufficient number
of observables as well as contamination from the ZZH vertex limits the precision to which anomalous part of the WWH coupling can be probed.
相似文献
20.
Probir Roy 《Pramana》2007,69(5):895-901
An event-shape analysis of the dileptons in the process e
+
e
− → ℓ+ℓ−
, studied in ILC or CLIC, can clearly discriminate between a supersymmetric or a large extra dimensional (ADD) production
mechanism.
相似文献