id
stringlengths
9
14
submitter
stringlengths
1
56
authors
stringlengths
5
7.68k
title
stringlengths
3
299
comments
stringlengths
1
1.15k
journal-ref
stringlengths
9
298
doi
stringlengths
12
97
report-no
stringlengths
3
341
categories
stringclasses
869 values
license
stringclasses
9 values
orig_abstract
stringlengths
16
2.44k
versions
listlengths
1
39
update_date
stringlengths
10
10
authors_parsed
listlengths
1
565
abstract
stringlengths
13
2.44k
2111.13731
Ismail Soudi
Soeren Schlichting and Ismail Soudi
Splitting rates in QCD plasmas from a non-perturbative determination of the momentum broadening kernel $C(q_{\bot})$
19 pages, 10 figures, pulished version
Phys.Rev.D 105 (2022) 7, 076002
10.1103/PhysRevD.105.076002
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
We exploit a recent non-perturbative determination of the momentum broadening kernel $C(b_{\bot})$ in impact parameter space \cite{Moore:2021jwe}, to determine the momentum space broadening kernel $C(q_{\bot})$ in high-temperature QCD plasmas. We show how to use the non-pertubatively determined kernel $C(q_{\bot})$ to compute the medium-induced splitting rates in a QCD plasma of finite size. We compare the resulting in-medium splitting rates to the results obtained with leading-order and next-to-leading order perturbative determinations of $C(q_{\bot})$, as well as with various approximations of the splitting employed in the literature. Generally, we find that the differences in the splitting rates due to the momentum broadening kernel are larger than the errors associated with approximations of the splitting rate.
[ { "created": "Fri, 26 Nov 2021 19:53:16 GMT", "version": "v1" }, { "created": "Fri, 27 May 2022 12:48:29 GMT", "version": "v2" } ]
2022-05-30
[ [ "Schlichting", "Soeren", "" ], [ "Soudi", "Ismail", "" ] ]
We exploit a recent non-perturbative determination of the momentum broadening kernel $C(b_{\bot})$ in impact parameter space \cite{Moore:2021jwe}, to determine the momentum space broadening kernel $C(q_{\bot})$ in high-temperature QCD plasmas. We show how to use the non-pertubatively determined kernel $C(q_{\bot})$ to compute the medium-induced splitting rates in a QCD plasma of finite size. We compare the resulting in-medium splitting rates to the results obtained with leading-order and next-to-leading order perturbative determinations of $C(q_{\bot})$, as well as with various approximations of the splitting employed in the literature. Generally, we find that the differences in the splitting rates due to the momentum broadening kernel are larger than the errors associated with approximations of the splitting rate.
1409.6970
Zhen-hua Zhao
Yu-Feng Li, Zhen-hua Zhao
Tests of Lorentz and CPT Violation in the Medium Baseline Reactor Antineutrino Experiment
16 pages, 12 figures, version accepted for publication in PRD
Phys. Rev. D 90, 113014 (2014)
10.1103/PhysRevD.90.113014
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Tests of Lorentz and CPT violation in the medium baseline reactor antineutrino experiment are presented in the framework of the Standard Model Extension (SME). Both the spectral distortion and sidereal variation are employed to derive the limits of Lorentz violation (LV) coefficients. We do the numerical analysis of the sensitivity of LV coefficients by taking the Jiangmen Underground Neutrino Observatory (JUNO) as an illustration, which can improve the sensitivity by more than two orders of magnitude compared with the current limits from reactor antineutrino experiments.
[ { "created": "Wed, 24 Sep 2014 14:28:25 GMT", "version": "v1" }, { "created": "Fri, 21 Nov 2014 03:05:24 GMT", "version": "v2" } ]
2015-01-07
[ [ "Li", "Yu-Feng", "" ], [ "Zhao", "Zhen-hua", "" ] ]
Tests of Lorentz and CPT violation in the medium baseline reactor antineutrino experiment are presented in the framework of the Standard Model Extension (SME). Both the spectral distortion and sidereal variation are employed to derive the limits of Lorentz violation (LV) coefficients. We do the numerical analysis of the sensitivity of LV coefficients by taking the Jiangmen Underground Neutrino Observatory (JUNO) as an illustration, which can improve the sensitivity by more than two orders of magnitude compared with the current limits from reactor antineutrino experiments.
2011.00530
David d'Enterria
David d'Enterria and Cynthia Yan
Revised QCD effects on the Z $\to b\bar{b}$ forward-backward asymmetry
12 pages, 3 figs, 3 tables
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The forward-backward (FB) asymmetry of $b$ quarks in $e^+e^-$ collisions at the Z pole measured at LEP, $A_{FB}^{0,b} = 0.0992\pm0.0016$, remains today the electroweak precision observable with the largest disagreement (2.4$\sigma$) with respect to the Standard Model prediction, $(A_{FB}^{0,b})_{_{\rm th}} = 0.1030 \pm 0.0002$. Beyond the dominant statistical uncertainties, QCD effects, such as $b$-quark showering and hadronization, are the leading sources of $A_{FB}^{0,b}$ systematic uncertainty, and have not been revised in the last twenty years. We reassess the QCD uncertainties of the eight original $A_{FB}^{0,b}$ LEP measurements, using modern parton shower PYTHIA-8 and PYTHIA-8 + VINCIA simulations with nine different implementations of soft and collinear radiation as well as of parton fragmentation. Our analysis, combined with NNLO massive $b$-quark corrections independently computed recently, indicates total propagated QCD uncertainties of $\sim$0.7% and $\sim$0.3% for the lepton-charge and jet-charge analyses, respectively, that are about a factor of two smaller than those of the original LEP results. Accounting for such updated QCD effects leads to a new $A_{FB}^{0,b} = 0.0996\pm0.0016$ average, with a data-theory tension slightly reduced from 2.4$\sigma$ to 2.1$\sigma$. Confirmation or resolution of this long-term discrepancy requires a new high-luminosity $e^+e^-$ collider collecting orders-of-magnitude more data at the Z pole to significantly reduce the $A_{FB}^{0,b}$ statistical uncertainties.
[ { "created": "Sun, 1 Nov 2020 15:17:51 GMT", "version": "v1" } ]
2020-11-03
[ [ "d'Enterria", "David", "" ], [ "Yan", "Cynthia", "" ] ]
The forward-backward (FB) asymmetry of $b$ quarks in $e^+e^-$ collisions at the Z pole measured at LEP, $A_{FB}^{0,b} = 0.0992\pm0.0016$, remains today the electroweak precision observable with the largest disagreement (2.4$\sigma$) with respect to the Standard Model prediction, $(A_{FB}^{0,b})_{_{\rm th}} = 0.1030 \pm 0.0002$. Beyond the dominant statistical uncertainties, QCD effects, such as $b$-quark showering and hadronization, are the leading sources of $A_{FB}^{0,b}$ systematic uncertainty, and have not been revised in the last twenty years. We reassess the QCD uncertainties of the eight original $A_{FB}^{0,b}$ LEP measurements, using modern parton shower PYTHIA-8 and PYTHIA-8 + VINCIA simulations with nine different implementations of soft and collinear radiation as well as of parton fragmentation. Our analysis, combined with NNLO massive $b$-quark corrections independently computed recently, indicates total propagated QCD uncertainties of $\sim$0.7% and $\sim$0.3% for the lepton-charge and jet-charge analyses, respectively, that are about a factor of two smaller than those of the original LEP results. Accounting for such updated QCD effects leads to a new $A_{FB}^{0,b} = 0.0996\pm0.0016$ average, with a data-theory tension slightly reduced from 2.4$\sigma$ to 2.1$\sigma$. Confirmation or resolution of this long-term discrepancy requires a new high-luminosity $e^+e^-$ collider collecting orders-of-magnitude more data at the Z pole to significantly reduce the $A_{FB}^{0,b}$ statistical uncertainties.
hep-ph/9509234
Xiang Qian Luo
Q.Z. Chen, S.H. Guo, X.Q. Luo, A. Segui
Spectroscopy and large scale wave functions
4 pages, uses fps.sty, fig1.ps and fig2.ps (appended)
Nucl.Phys.Proc.Suppl. 47 (1996) 274
10.1016/0920-5632(96)00055-2
HLRZ-95-51
hep-ph
null
We discuss the relevance of long wavelength excitations for the low energy spectrum of QCD, and try to develop an efficient method for solving the Schrodinger equation, and for extracting the glueball masses and long wavelength functions of the ground and excited states. Some technical problems appearing in the calculations of SU(3) gauge theory are discussed.
[ { "created": "Wed, 6 Sep 1995 11:02:07 GMT", "version": "v1" } ]
2015-06-25
[ [ "Chen", "Q. Z.", "" ], [ "Guo", "S. H.", "" ], [ "Luo", "X. Q.", "" ], [ "Segui", "A.", "" ] ]
We discuss the relevance of long wavelength excitations for the low energy spectrum of QCD, and try to develop an efficient method for solving the Schrodinger equation, and for extracting the glueball masses and long wavelength functions of the ground and excited states. Some technical problems appearing in the calculations of SU(3) gauge theory are discussed.
1601.07880
Tania Robens
Tania Robens and Tim Stefaniak
LHC Benchmark Scenarios for the Real Higgs Singlet Extension of the Standard Model
23 pages, 9 tables, 4 figures. arXiv admin note: text overlap with arXiv:1501.02234; v2: one subsection, one figure, and some references added, minor errors corrected. Corresponds to published journal version
Eur.Phys.J. C76 (2016) no.5, 268
10.1140/epjc/s10052-016-4115-8
SCIPP 16/03
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present benchmark scenarios for searches for an additional Higgs state in the real Higgs singlet extension of the Standard Model in Run 2 of the LHC. The scenarios are selected such that they fulfill all relevant current theoretical and experimental constraints, but can potentially be discovered at the current LHC run. We take into account the results presented in earlier work and update the experimental constraints from relevant LHC Higgs searches and signal rate measurements. The benchmark scenarios are given separately for the low mass and high mass region, i.e. the mass range where the additional Higgs state is lighter or heavier than the discovered Higgs state at around 125 GeV. They have also been presented in the framework of the LHC Higgs Cross Section Working Group.
[ { "created": "Thu, 28 Jan 2016 19:48:55 GMT", "version": "v1" }, { "created": "Wed, 25 May 2016 11:24:14 GMT", "version": "v2" } ]
2016-05-26
[ [ "Robens", "Tania", "" ], [ "Stefaniak", "Tim", "" ] ]
We present benchmark scenarios for searches for an additional Higgs state in the real Higgs singlet extension of the Standard Model in Run 2 of the LHC. The scenarios are selected such that they fulfill all relevant current theoretical and experimental constraints, but can potentially be discovered at the current LHC run. We take into account the results presented in earlier work and update the experimental constraints from relevant LHC Higgs searches and signal rate measurements. The benchmark scenarios are given separately for the low mass and high mass region, i.e. the mass range where the additional Higgs state is lighter or heavier than the discovered Higgs state at around 125 GeV. They have also been presented in the framework of the LHC Higgs Cross Section Working Group.
1305.5042
Jian Zhou Mr.
Andreas Sch\"afer and Jian Zhou
On the process dependent nuclear $k_\perp$ broadening effect
17 pages, 3 figures
Phys. Rev. D 88, 074012 (2013)
10.1103/PhysRevD.88.074012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the process dependent nuclear $k_\perp$ broadening effect by employing the transverse momentum dependent(TMD) factorization approach in combination with the Mclerran-Venugopalan(MV) model. More specifically, we investigate how the parton transverse momentum distributions are affected by the process dependent gauge links in cold nuclear matter. In particular, our analysis also applies to the polarized cases including the nuclear quark Boer-Mulders function and the linearly polarized gluon distribution. Our main focus is on the nuclear TMDs at intermediate or large x.
[ { "created": "Wed, 22 May 2013 08:07:31 GMT", "version": "v1" } ]
2013-10-30
[ [ "Schäfer", "Andreas", "" ], [ "Zhou", "Jian", "" ] ]
We study the process dependent nuclear $k_\perp$ broadening effect by employing the transverse momentum dependent(TMD) factorization approach in combination with the Mclerran-Venugopalan(MV) model. More specifically, we investigate how the parton transverse momentum distributions are affected by the process dependent gauge links in cold nuclear matter. In particular, our analysis also applies to the polarized cases including the nuclear quark Boer-Mulders function and the linearly polarized gluon distribution. Our main focus is on the nuclear TMDs at intermediate or large x.
1504.01768
Natascia Vignaroli
Natascia Vignaroli
Z-peaked excess from heavy gluon decays to vector-like quarks
23 pp. v2: minor changes, references added
Phys. Rev. D 91, 115009 (2015)
10.1103/PhysRevD.91.115009
MSUHEP-150407
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A 3 sigma excess has been recently announced by ATLAS in events with Z-peaked dilepton pairs, jets, and large transverse missing energy. We interpret this finding in the context of composite Higgs / RS theories. We find that composite Higgs theories with custodial symmetry protection to the $Zb\bar{b}$ coupling predict a significant contribution to $ZZbb$ (and to $hhbb$) final states coming from heavy gluon decays to pairs of bottom-partner vector-like quarks. The heavy gluon to vector-like quarks signal is largely accepted by the ATLAS selection if one of the $Z$ boson in the $ZZbb$ final state decays leptonically and the other to neutrinos. For a bottom partner of $\sim$900 GeV, we find that the ATLAS excess can be reproduced by composite Higgs models, in an experimentally allowed parameter space, for heavy gluon masses roughly in a range 1.87 - 2.15 TeV and for heavy gluon couplings to light quarks within $\sim(0.3-0.65) g_S$. We briefly discuss the implication of this result for future experimental tests.
[ { "created": "Tue, 7 Apr 2015 22:03:52 GMT", "version": "v1" }, { "created": "Tue, 14 Apr 2015 19:14:38 GMT", "version": "v2" } ]
2015-06-17
[ [ "Vignaroli", "Natascia", "" ] ]
A 3 sigma excess has been recently announced by ATLAS in events with Z-peaked dilepton pairs, jets, and large transverse missing energy. We interpret this finding in the context of composite Higgs / RS theories. We find that composite Higgs theories with custodial symmetry protection to the $Zb\bar{b}$ coupling predict a significant contribution to $ZZbb$ (and to $hhbb$) final states coming from heavy gluon decays to pairs of bottom-partner vector-like quarks. The heavy gluon to vector-like quarks signal is largely accepted by the ATLAS selection if one of the $Z$ boson in the $ZZbb$ final state decays leptonically and the other to neutrinos. For a bottom partner of $\sim$900 GeV, we find that the ATLAS excess can be reproduced by composite Higgs models, in an experimentally allowed parameter space, for heavy gluon masses roughly in a range 1.87 - 2.15 TeV and for heavy gluon couplings to light quarks within $\sim(0.3-0.65) g_S$. We briefly discuss the implication of this result for future experimental tests.
0707.3196
Masaharu Iwasaki
Takahiko Fukutome and Masaharu Iwasaki
Effect of Soft Modes on the Shear Viscosity of Quark Matter
8 pages, 11 figures
Prog.Theor.Phys.119:991-1004,2008
10.1143/PTP.119.991
null
hep-ph
null
We calculate shear viscosity of the quark matter at finite temperature and density. If we assume that the quark interacts with the soft mode, which is a collective mode of quark-antiquark pair, the self energy of the quark is calculated by using the quasi-particle random phase approximation. It is shown that its imaginary part is large and the mean free path of the quark is short. With the use of the Kubo formula, the shear viscosity of quark matter becomes small. The Reynolds number of the quark matter is estimated to be about $3\sim 30$. As the temperature increases, the shear viscosity increases gradually for $T>200{\rm MeV}$. Moreover it is shown that the shear viscosity is not sensitive to the chemical potential.
[ { "created": "Sat, 21 Jul 2007 08:30:07 GMT", "version": "v1" } ]
2008-11-26
[ [ "Fukutome", "Takahiko", "" ], [ "Iwasaki", "Masaharu", "" ] ]
We calculate shear viscosity of the quark matter at finite temperature and density. If we assume that the quark interacts with the soft mode, which is a collective mode of quark-antiquark pair, the self energy of the quark is calculated by using the quasi-particle random phase approximation. It is shown that its imaginary part is large and the mean free path of the quark is short. With the use of the Kubo formula, the shear viscosity of quark matter becomes small. The Reynolds number of the quark matter is estimated to be about $3\sim 30$. As the temperature increases, the shear viscosity increases gradually for $T>200{\rm MeV}$. Moreover it is shown that the shear viscosity is not sensitive to the chemical potential.
2211.09637
Michael Edmund Tobar
Michael E. Tobar, Catriona A. Thomson, Benjamin T. McAllister, Maxim Goryachev, Anton Sokolov, Andreas Ringwald
Sensitivity of Resonant Axion Haloscopes to Quantum Electromagnetodynamics
Published Version in Annalen der Physik https://onlinelibrary.wiley.com/doi/epdf/10.1002/andp.202200594
Ann. Phys.(Berlin) 2023, 2200594
10.1002/andp.202200594
null
hep-ph gr-qc hep-ex physics.ins-det quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently interactions between putative axions and magnetic monopoles have been revisited by two of us [arXiv:2205.02605 [hep-ph]]. It has been shown that significant modifications to conventional axion electrodynamics arise due to these interactions, so that the axion-photon coupling parameter space is expanded from one parameter $g_{a\gamma\gamma}$ to three $(g_{a\gamma\gamma},g_{aAB},g_{aBB})$. We implement Poynting theorem to determine how to exhibit sensitivity to $g_{aAB}$ and $g_{aBB}$ using resonant haloscopes, allowing new techniques to search for axions and a possible indirect way to determine if magnetically charged matter exists.
[ { "created": "Thu, 17 Nov 2022 16:38:42 GMT", "version": "v1" }, { "created": "Mon, 24 Apr 2023 07:37:31 GMT", "version": "v2" } ]
2023-04-25
[ [ "Tobar", "Michael E.", "" ], [ "Thomson", "Catriona A.", "" ], [ "McAllister", "Benjamin T.", "" ], [ "Goryachev", "Maxim", "" ], [ "Sokolov", "Anton", "" ], [ "Ringwald", "Andreas", "" ] ]
Recently interactions between putative axions and magnetic monopoles have been revisited by two of us [arXiv:2205.02605 [hep-ph]]. It has been shown that significant modifications to conventional axion electrodynamics arise due to these interactions, so that the axion-photon coupling parameter space is expanded from one parameter $g_{a\gamma\gamma}$ to three $(g_{a\gamma\gamma},g_{aAB},g_{aBB})$. We implement Poynting theorem to determine how to exhibit sensitivity to $g_{aAB}$ and $g_{aBB}$ using resonant haloscopes, allowing new techniques to search for axions and a possible indirect way to determine if magnetically charged matter exists.
1111.6594
Maxim Perelstein
Joshua Berger, Maxim Perelstein, Michael Saelim, Andrew Spray
Boosted Tops from Gluino Decays
5 pages, 3 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Naturalness considerations, together with the non-observation of superpartners of the Standard Model particles at the Large Hadron Collider (LHC) so far, favor supersymmetric (SUSY) models in which third generation squarks are significantly lighter than those of the first two generations. In such models, gluino pair-production is typically the dominant SUSY production process at the LHC, and it often leads to final states with multiple top quarks. Some of these top quarks may be relativistic in the lab frame, in which case their hadronic decays may produce "top jets". We propose that the recently developed techniques for tagging top jets can be used to boost sensitivity of the LHC searches for this scenario. For example, within the simplified model used for this study, we estimate that a search with 2 top-tagged jets can probe gluino masses of up to about 1 TeV at the 7 TeV LHC with 30 inverse fb integrated luminosity.
[ { "created": "Mon, 28 Nov 2011 21:00:06 GMT", "version": "v1" } ]
2011-12-09
[ [ "Berger", "Joshua", "" ], [ "Perelstein", "Maxim", "" ], [ "Saelim", "Michael", "" ], [ "Spray", "Andrew", "" ] ]
Naturalness considerations, together with the non-observation of superpartners of the Standard Model particles at the Large Hadron Collider (LHC) so far, favor supersymmetric (SUSY) models in which third generation squarks are significantly lighter than those of the first two generations. In such models, gluino pair-production is typically the dominant SUSY production process at the LHC, and it often leads to final states with multiple top quarks. Some of these top quarks may be relativistic in the lab frame, in which case their hadronic decays may produce "top jets". We propose that the recently developed techniques for tagging top jets can be used to boost sensitivity of the LHC searches for this scenario. For example, within the simplified model used for this study, we estimate that a search with 2 top-tagged jets can probe gluino masses of up to about 1 TeV at the 7 TeV LHC with 30 inverse fb integrated luminosity.
2311.05509
Oleksandr Zenaiev
M.V. Garzelli, J. Mazzitelli, S.-O. Moch, O. Zenaiev
Top-quark pole mass extraction at NNLO accuracy, from total, single- and double-differential cross sections for $t\bar{t}+X$ production at the LHC
null
JHEP05(2024)321
10.1007/JHEP05(2024)321
DESY-23-179, PSI-PR-23-42
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extract the top-quark mass value in the on-shell renormalization scheme from the comparison of theoretical predictions for $pp \rightarrow t\bar{t} + X$ at next-to-next-to-leading order (NNLO) QCD accuracy with experimental data collected by the ATLAS and CMS collaborations for absolute total, normalized single-differential and double-differential cross-sections during Run 1, Run 2 and the ongoing Run 3 at the Large Hadron Collider (LHC). For the theory computations of heavy-quark pair-production we use the MATRIX framework, interfaced to PineAPPL for the generation of grids of theory predictions, which can be efficiently used a-posteriori during the fit, performed within xFitter. We take several state-of-the-art parton distribution functions (PDFs) as input for the fit and evaluate their associated uncertainties, as well as the uncertainties arising from renormalization and factorization scale variation. Fit uncertainties related to the datasets are also part of the extracted uncertainty of the top-quark mass and turn out to be of similar size as the combined scale and PDF uncertainty. Fit results from different PDF sets agree among each other within 1$\sigma$ uncertainty, whereas some datasets related to $t\bar{t}$ decay in different channels (dileptonic vs. semileptonic) point towards top-quark mass values in slight tension among each other, although still compatible within $2.5 \sigma$ accuracy. Our results are compatible with the PDG 2022 top-quark pole-mass value. Our work opens the road towards more complex simultaneous NNLO fits of PDFs, the strong coupling $\alpha_s(M_Z)$ and the top-quark mass, using the currently most precise experimental data on $t\bar{t} + X$ total and multi-differential cross-sections from the LHC.
[ { "created": "Thu, 9 Nov 2023 16:49:59 GMT", "version": "v1" }, { "created": "Tue, 21 Nov 2023 18:51:25 GMT", "version": "v2" }, { "created": "Wed, 29 May 2024 21:19:35 GMT", "version": "v3" } ]
2024-05-31
[ [ "Garzelli", "M. V.", "" ], [ "Mazzitelli", "J.", "" ], [ "Moch", "S. -O.", "" ], [ "Zenaiev", "O.", "" ] ]
We extract the top-quark mass value in the on-shell renormalization scheme from the comparison of theoretical predictions for $pp \rightarrow t\bar{t} + X$ at next-to-next-to-leading order (NNLO) QCD accuracy with experimental data collected by the ATLAS and CMS collaborations for absolute total, normalized single-differential and double-differential cross-sections during Run 1, Run 2 and the ongoing Run 3 at the Large Hadron Collider (LHC). For the theory computations of heavy-quark pair-production we use the MATRIX framework, interfaced to PineAPPL for the generation of grids of theory predictions, which can be efficiently used a-posteriori during the fit, performed within xFitter. We take several state-of-the-art parton distribution functions (PDFs) as input for the fit and evaluate their associated uncertainties, as well as the uncertainties arising from renormalization and factorization scale variation. Fit uncertainties related to the datasets are also part of the extracted uncertainty of the top-quark mass and turn out to be of similar size as the combined scale and PDF uncertainty. Fit results from different PDF sets agree among each other within 1$\sigma$ uncertainty, whereas some datasets related to $t\bar{t}$ decay in different channels (dileptonic vs. semileptonic) point towards top-quark mass values in slight tension among each other, although still compatible within $2.5 \sigma$ accuracy. Our results are compatible with the PDG 2022 top-quark pole-mass value. Our work opens the road towards more complex simultaneous NNLO fits of PDFs, the strong coupling $\alpha_s(M_Z)$ and the top-quark mass, using the currently most precise experimental data on $t\bar{t} + X$ total and multi-differential cross-sections from the LHC.
hep-ph/0608188
Hee-Jung Lee
Hee-Jung Lee, N.I. Kochelev
Instanton interpolating current for $\sigma$--tetraquark
11 pages, 7 figures, final version to be appeared in Phys. Lett. B
Phys.Lett.B642:358-365,2006
10.1016/j.physletb.2006.09.049
SNUTP/06-007
hep-ph hep-ex nucl-ex nucl-th
null
We perform a QCD sum rule analysis for the light scalar meson $\sigma$ ($f_0(600)$) with a tetraquark current related to the instanton picture for QCD vacuum. We demonstrate that instanton current, including equal weights of scalar and pseudoscalar diquark-antidiquarks, leads to a strong cancelation between the contributions of high dimension operators in the operator product expansion (OPE). Furthermore, in the case of this current direct instanton contributions do not spoil the sum rules. Our calculation, obtained from the OPE up to dimension 10 operators, gives the mass of $\sigma$--meson around 780MeV.
[ { "created": "Thu, 17 Aug 2006 07:10:01 GMT", "version": "v1" }, { "created": "Wed, 23 Aug 2006 05:35:13 GMT", "version": "v2" }, { "created": "Wed, 4 Oct 2006 06:37:42 GMT", "version": "v3" } ]
2008-11-26
[ [ "Lee", "Hee-Jung", "" ], [ "Kochelev", "N. I.", "" ] ]
We perform a QCD sum rule analysis for the light scalar meson $\sigma$ ($f_0(600)$) with a tetraquark current related to the instanton picture for QCD vacuum. We demonstrate that instanton current, including equal weights of scalar and pseudoscalar diquark-antidiquarks, leads to a strong cancelation between the contributions of high dimension operators in the operator product expansion (OPE). Furthermore, in the case of this current direct instanton contributions do not spoil the sum rules. Our calculation, obtained from the OPE up to dimension 10 operators, gives the mass of $\sigma$--meson around 780MeV.
hep-ph/9702421
null
Yuval Grossman and Howard E. Haber
Sneutrino Mixing Phenomena
12 pages, revtex + axodraw, 1 figure included. Minor changes
Phys.Rev.Lett. 78 (1997) 3438-3441
10.1103/PhysRevLett.78.3438
SLAC-PUB-7423, SCIPP 97/02
hep-ph
null
In any model with nonzero Majorana neutrino masses, the sneutrino and antisneutrino of the supersymmetric extended theory mix. We outline the conditions under which sneutrino-antisneutrino mixing is experimentally observable. The mass-splitting of the sneutrino mass eigenstates and sneutrino oscillation phenomena are considered.
[ { "created": "Tue, 25 Feb 1997 21:47:42 GMT", "version": "v1" }, { "created": "Thu, 6 Mar 1997 18:26:33 GMT", "version": "v2" } ]
2009-10-30
[ [ "Grossman", "Yuval", "" ], [ "Haber", "Howard E.", "" ] ]
In any model with nonzero Majorana neutrino masses, the sneutrino and antisneutrino of the supersymmetric extended theory mix. We outline the conditions under which sneutrino-antisneutrino mixing is experimentally observable. The mass-splitting of the sneutrino mass eigenstates and sneutrino oscillation phenomena are considered.
hep-ph/0107015
Yuri V. Kovchegov
Yuri V. Kovchegov (U. of Washington), Mark Strikman (Penn State U.)
Ioffe Time in Double Logarithmic Approximation
13 pages, 1 figure
Phys.Lett.B516:314-320,2001
10.1016/S0370-2693(01)00953-4
NT@UW-01-015
hep-ph nucl-th
null
We analyze the light cone (Ioffe) time structure of the gluon distribution function in the double logarithmic approximation. We show that due to QCD evolution Ioffe equation is modified. The characteristic light cone time of the gluons does not increase as fast with increasing energy (decreasing Bjorken x) as predicted by the parton distributions exhibiting Bjorken scaling due to the increase of the transverse momenta of the gluons in the DGLAP ladder.
[ { "created": "Mon, 2 Jul 2001 21:34:43 GMT", "version": "v1" }, { "created": "Wed, 25 Jul 2001 01:13:26 GMT", "version": "v2" } ]
2014-11-17
[ [ "Kovchegov", "Yuri V.", "", "U. of Washington" ], [ "Strikman", "Mark", "", "Penn State U." ] ]
We analyze the light cone (Ioffe) time structure of the gluon distribution function in the double logarithmic approximation. We show that due to QCD evolution Ioffe equation is modified. The characteristic light cone time of the gluons does not increase as fast with increasing energy (decreasing Bjorken x) as predicted by the parton distributions exhibiting Bjorken scaling due to the increase of the transverse momenta of the gluons in the DGLAP ladder.
hep-ph/9803448
Yuichiro Kiyo
Yuichiro Kiyo, Jiro Kodaira and Hiroshi Tochimura
The Small $x$ Behavior of $g_1$ in the Resummed Approach
9 pages, ps figures included, sprocl.sty, psfig.sty, and here.sty are required. Invited talk presented at the International Symposium on ``QCD Corrections and New Physics'' October 27-29, 1997 Hiroshima, Japan
null
null
HUPD-9808
hep-ph
null
The double logarithmic terms $\alpha_{s} \ln^{2}x $ are important to predict precisely the small $x$ behavior of the spin structure function $g_{1}$. We numerically analyze the evolution of the flavor non-singlet $g_{1}$ including the all-order resummed effect of these terms. It is pointed out that the next-to-leading logarithmic corrections produce an unexpectedly large suppression factor over the experimentally accessible range of $x$ and $Q^{2}$. This implies that the next-to-leading logarithmic contributions are very important in order to obtain a definite prediction.
[ { "created": "Wed, 25 Mar 1998 17:10:07 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kiyo", "Yuichiro", "" ], [ "Kodaira", "Jiro", "" ], [ "Tochimura", "Hiroshi", "" ] ]
The double logarithmic terms $\alpha_{s} \ln^{2}x $ are important to predict precisely the small $x$ behavior of the spin structure function $g_{1}$. We numerically analyze the evolution of the flavor non-singlet $g_{1}$ including the all-order resummed effect of these terms. It is pointed out that the next-to-leading logarithmic corrections produce an unexpectedly large suppression factor over the experimentally accessible range of $x$ and $Q^{2}$. This implies that the next-to-leading logarithmic contributions are very important in order to obtain a definite prediction.
0807.2951
Elena Accomando
E. Accomando, S. De Curtis, D. Dominici and L. Fedeli (Florence U. & INFN, Florence)
The four site Higgsless model at the LHC
To appear in the proceedings of the "Incontri di Fisica delle Alte Energie" (IFAE 2008), Bologna, 26-28 March 2008
Nuovo Cim.B123:809-811,2008
10.1393/ncb/i2008-10609-4
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the four-site Higgsless model, which predicts the existence of four charged and two neutral extra gauge bosons, $W_{1,2}^\pm$ and $Z_{1,2}$. In contrast to other Higgsless models, characterized by fermiophobic extra gauge bosons, here sizeable fermion-boson couplings are allowed by the electroweak precision data. We thus analyse the prospects of detecting the new predicted particles in the mostly favored Drell-Yan channel at the LHC.
[ { "created": "Fri, 18 Jul 2008 13:59:58 GMT", "version": "v1" } ]
2010-11-11
[ [ "Accomando", "E.", "", "Florence U. &\n INFN, Florence" ], [ "De Curtis", "S.", "", "Florence U. &\n INFN, Florence" ], [ "Dominici", "D.", "", "Florence U. &\n INFN, Florence" ], [ "Fedeli", "L.", "", "Florence U. &\n INFN, Florence" ] ]
We consider the four-site Higgsless model, which predicts the existence of four charged and two neutral extra gauge bosons, $W_{1,2}^\pm$ and $Z_{1,2}$. In contrast to other Higgsless models, characterized by fermiophobic extra gauge bosons, here sizeable fermion-boson couplings are allowed by the electroweak precision data. We thus analyse the prospects of detecting the new predicted particles in the mostly favored Drell-Yan channel at the LHC.
hep-ph/9504426
Tao Han
J. Bagger, V. Barger, K. Cheung, J. Gunion, T. Han, G. A. Ladinsky, R. Rosenfeld, C.--P. Yuan
LHC Analysis of the Strongly Interacting $WW$ System: Gold-Plated Modes
14 pages, LaTeX, final version (with minor changes) to appear in Phys. Rev. D; postscript file available via anonymous ftp at ftp://ucdhep.ucdavis.edu/han/sews/paper_ww.ps and figure files separated as figs.uu or *.ps
Phys.Rev.D52:3878-3889,1995
10.1103/PhysRevD.52.3878
JHU-TIPAC-95012, MADPH-95-877, CPP-95-3, DOE-ER40757-063, UCD-95-08, MSUHEP-50305, IFUSP/P-1141
hep-ph
null
We study the gold-plated purely leptonic signal and background rates at the LHC for the $ZZ,$ $W^{+}W^-,$ $W^\pm Z$ and $W^\pm W^\pm$ final states associated with strongly interacting electroweak symmetry breaking. We work at an energy of $\sqrt s = 14$ TeV, and develop a combination of back-to-back leptonic, central-jet-vetoing and forwaring cuts that suppresses the Standard-Model backgrounds. We find that the LHC with an annual luminosity of 100 fb$^{-1}$ will achieve a reasonably good sensitivity to the physics of strongly interacting electroweak symmetry breaking.
[ { "created": "Fri, 28 Apr 1995 23:54:01 GMT", "version": "v1" }, { "created": "Tue, 18 Jul 1995 07:22:48 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bagger", "J.", "" ], [ "Barger", "V.", "" ], [ "Cheung", "K.", "" ], [ "Gunion", "J.", "" ], [ "Han", "T.", "" ], [ "Ladinsky", "G. A.", "" ], [ "Rosenfeld", "R.", "" ], [ "Yuan", "C. --P.", "" ] ]
We study the gold-plated purely leptonic signal and background rates at the LHC for the $ZZ,$ $W^{+}W^-,$ $W^\pm Z$ and $W^\pm W^\pm$ final states associated with strongly interacting electroweak symmetry breaking. We work at an energy of $\sqrt s = 14$ TeV, and develop a combination of back-to-back leptonic, central-jet-vetoing and forwaring cuts that suppresses the Standard-Model backgrounds. We find that the LHC with an annual luminosity of 100 fb$^{-1}$ will achieve a reasonably good sensitivity to the physics of strongly interacting electroweak symmetry breaking.
1506.05994
She-Sheng Xue
She-Sheng Xue
Vectorlike $W^\pm$-boson coupling at TeV and third family fermion masses
The revised version to appear in Phys. Rev. D. The title has been modified. 23 pages and 5 figures
Phys. Rev. D 93, 073001 (2016)
10.1103/PhysRevD.93.073001
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the third fermion family and gauge symmetry of the Standard Model, we study the quark-quark, lepton-lepton and quark-lepton four-fermion operators in an effective theory at high energies. These operators have nontrivial contributions to the Schwinger-Dyson equations for fermion self-energy functions and the $W^\pm$-boson coupling vertex. As a result, the top-quark mass is generated via the spontaneous symmetry breaking of $\langle\bar t t \rangle$-condensate and the $W^\pm$-boson coupling becomes approximately vectorlike at TeV scale. The bottom-quark, tau-lepton and tau-neutrino masses are generated via the explicit symmetry breaking of $W^\pm$-contributions and quark-lepton interactions. Their masses and Yukawa couplings are functions of the top-quark mass and Yukawa coupling. We qualitatively show the hierarchy of fermion masses and Yukawa couplings of the third fermion family. We also discuss the possible collider signatures due to the vectorlike (parity-restoration) feature of $W^\pm$-boson coupling at high energies.
[ { "created": "Thu, 18 Jun 2015 17:26:15 GMT", "version": "v1" }, { "created": "Fri, 4 Sep 2015 07:48:42 GMT", "version": "v2" }, { "created": "Tue, 22 Mar 2016 10:36:38 GMT", "version": "v3" } ]
2016-04-20
[ [ "Xue", "She-Sheng", "" ] ]
In the third fermion family and gauge symmetry of the Standard Model, we study the quark-quark, lepton-lepton and quark-lepton four-fermion operators in an effective theory at high energies. These operators have nontrivial contributions to the Schwinger-Dyson equations for fermion self-energy functions and the $W^\pm$-boson coupling vertex. As a result, the top-quark mass is generated via the spontaneous symmetry breaking of $\langle\bar t t \rangle$-condensate and the $W^\pm$-boson coupling becomes approximately vectorlike at TeV scale. The bottom-quark, tau-lepton and tau-neutrino masses are generated via the explicit symmetry breaking of $W^\pm$-contributions and quark-lepton interactions. Their masses and Yukawa couplings are functions of the top-quark mass and Yukawa coupling. We qualitatively show the hierarchy of fermion masses and Yukawa couplings of the third fermion family. We also discuss the possible collider signatures due to the vectorlike (parity-restoration) feature of $W^\pm$-boson coupling at high energies.
hep-ph/9810283
Kiselev Valery V.
V.V. Kiselev, A.I. Onishchenko
Two-loop anomalous dimensions for currents of baryons with two heavy quarks in NRQCD
Latex file, 13 page, 1 postscript figure
null
null
IHEP 98-64
hep-ph
null
We present analytical results on the two-loop anomalous dimensions of currents for baryons, containing two heavy quarks $J = [Q^{iT}C\Gamma\tau Q^j]\Gamma' q^k\epsilon_{ijk}$ with arbitrary Dirac matrices $\Gamma$ and $\Gamma'$ in the framework of NRQCD in the leading order over both the relative velocity of heavy quarks and the inverse heavy quark mass. It is shown, that in this approximation the anomalous dimensions do not depend on the Dirac structure of the current under consideration.
[ { "created": "Thu, 8 Oct 1998 04:54:41 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kiselev", "V. V.", "" ], [ "Onishchenko", "A. I.", "" ] ]
We present analytical results on the two-loop anomalous dimensions of currents for baryons, containing two heavy quarks $J = [Q^{iT}C\Gamma\tau Q^j]\Gamma' q^k\epsilon_{ijk}$ with arbitrary Dirac matrices $\Gamma$ and $\Gamma'$ in the framework of NRQCD in the leading order over both the relative velocity of heavy quarks and the inverse heavy quark mass. It is shown, that in this approximation the anomalous dimensions do not depend on the Dirac structure of the current under consideration.
hep-ph/9510433
Csaba Boros
C.Boros
New results of the Berliner relativistic quark model
Plenary talk given at the VI. International Workshop on Spin Phenomena in High Energy Physics, Protvino, Russia September 18-23
null
null
FUB-HEP/95-16
hep-ph
null
It is pointed out that the recently measured left-right asymmetries in inclusive pion and lambda hyperon production processes are in very good agreement with the relativistic quark model, proposed some time ago. Further predictions based on this model for hyperon productions, for lepton pair productions and for W/Z-boson productions are also presented.
[ { "created": "Fri, 27 Oct 1995 14:44:49 GMT", "version": "v1" } ]
2007-05-23
[ [ "Boros", "C.", "" ] ]
It is pointed out that the recently measured left-right asymmetries in inclusive pion and lambda hyperon production processes are in very good agreement with the relativistic quark model, proposed some time ago. Further predictions based on this model for hyperon productions, for lepton pair productions and for W/Z-boson productions are also presented.
1610.04501
Tord Riemann
T. Riemann (Koenigs Wusterhausen)
S-matrix approach to the Z resonance
10 pages, Proceedings of 39th International Conference of Theoretical Physics: Matter to the Deepest, Recent Developments in Physics of Fundamental Interactions, 13-18 September 2015, Ustron, Poland; presented also at the FCC-ee meeting, February 2015, Pisa; at CALC, July 2015, JINR, Dubna; at HEPKIT, October 2015, KIT, Karlsruhe. Note added on 14 October 2016
Acta Phys. Polon. B46 (2015) no.11, 2235
10.5506/APhysPolB.46.2235
KW 15-001
hep-ph
http://creativecommons.org/licenses/by-sa/4.0/
The proposed $e^+e^-$-collider FCC-ee aims at an unprecedented accuracy for $e^+e^-$ collisions into fermion pairs at the $Z$ peak, based on about $10^{13}$ events. The S-matrix approach to the $Z$ boson line shape allows the model-independent quantitative description of the reaction $e^+e^- \to {\bar f}f$ around the $Z$ peak in terms of few parameters, among them the mass $M_Z$ and width $\Gamma_Z$ of the $Z$-boson. While weak and strong corrections remain "black", a careful theoretical description of the photonic interactions is mandatory. I introduce the method and describe applications and the analysis tool SMATASY/ZFITTER.
[ { "created": "Fri, 14 Oct 2016 15:32:19 GMT", "version": "v1" } ]
2016-10-17
[ [ "Riemann", "T.", "", "Koenigs Wusterhausen" ] ]
The proposed $e^+e^-$-collider FCC-ee aims at an unprecedented accuracy for $e^+e^-$ collisions into fermion pairs at the $Z$ peak, based on about $10^{13}$ events. The S-matrix approach to the $Z$ boson line shape allows the model-independent quantitative description of the reaction $e^+e^- \to {\bar f}f$ around the $Z$ peak in terms of few parameters, among them the mass $M_Z$ and width $\Gamma_Z$ of the $Z$-boson. While weak and strong corrections remain "black", a careful theoretical description of the photonic interactions is mandatory. I introduce the method and describe applications and the analysis tool SMATASY/ZFITTER.
2209.13741
Joris Vergeest
Bartosz Dziewit, Marek Zralek, Joris Vergeest and Piotr Chaber
A method to explore flavor symmetries of the 3HDM and their implications on lepton masses and mixing
arXiv admin note: text overlap with arXiv:2203.03514
Symmetry 2022, 14(9), 185
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present a method to identify symmetry groups of the Yukawa sector of the three-Higgs-doublet model and to determine the implication that the symmetry has on the lepton masses and mixing. The method can accommodate different hypotheses about the group representation assignments, and thus support the exploration of candidate symmetry groups. For one particular representation selection scheme we apply the computer-implemented method to scan all discrete groups of order less than 1035. It can be proven that none of these groups defines a flavor symmetry that implies masses and neutrino mixing angles consistent with the experimental lepton data, although several cases are found that are partially or approximately consistent.
[ { "created": "Tue, 27 Sep 2022 23:24:45 GMT", "version": "v1" } ]
2022-09-29
[ [ "Dziewit", "Bartosz", "" ], [ "Zralek", "Marek", "" ], [ "Vergeest", "Joris", "" ], [ "Chaber", "Piotr", "" ] ]
We present a method to identify symmetry groups of the Yukawa sector of the three-Higgs-doublet model and to determine the implication that the symmetry has on the lepton masses and mixing. The method can accommodate different hypotheses about the group representation assignments, and thus support the exploration of candidate symmetry groups. For one particular representation selection scheme we apply the computer-implemented method to scan all discrete groups of order less than 1035. It can be proven that none of these groups defines a flavor symmetry that implies masses and neutrino mixing angles consistent with the experimental lepton data, although several cases are found that are partially or approximately consistent.
hep-ph/0207279
Bodenm\"uller
H. Fritzsch
Mesons, Quarks and Leptons
15 pages
null
null
LMU 08/01
hep-ph
null
The QCD anomaly leads to an abnormal mixing and mass pattern for the pseudoscalar mesons. Furthermore it is responsible for the quality of isospin symmetry in the meson spectrum. Similarities between the large mixing angles among the neutral 0^-+ mesons and the large mixing angles observed in neutrino oscillations are pointed out.
[ { "created": "Tue, 23 Jul 2002 13:04:32 GMT", "version": "v1" } ]
2007-05-23
[ [ "Fritzsch", "H.", "" ] ]
The QCD anomaly leads to an abnormal mixing and mass pattern for the pseudoscalar mesons. Furthermore it is responsible for the quality of isospin symmetry in the meson spectrum. Similarities between the large mixing angles among the neutral 0^-+ mesons and the large mixing angles observed in neutrino oscillations are pointed out.
1203.4435
Emiliano Molinaro
A. Meroni, E. Molinaro, S. T. Petcov
Revisiting Leptogenesis in a SUSY SU(5) x T' Model of Flavour
14 pages, 1 figure; published version
null
10.1016/j.physletb.2012.03.006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the generation of the baryon asymmetry of the Universe within a SUSY SU(5) x T' model of flavour, which gives rise to realistic masses and mixing patterns for quarks and leptons. The model employs the see-saw mechanism for generation of the light neutrino masses and the baryon asymmetry is produced via leptogenesis. We perform detailed calculations of both the CP violating lepton asymmetries, originating from the decays of the heavy Majorana neutrinos operative in the see-saw mechanism, and of the efficiency factors which account for the lepton asymmetry wash-out processes in the Early Universe. The latter are calculated by solving numerically the system of Boltzmann equations describing the generation and the evolution of the lepton asymmetries. The baryon asymmetry in the model considered is proportional to the J_{CP} factor, which determines the magnitude of CP violation effects in the oscillations of flavour neutrinos. The leptogenesis scale can be sufficiently low, allowing to avoid the potential gravitino problem.
[ { "created": "Tue, 20 Mar 2012 13:43:04 GMT", "version": "v1" } ]
2012-03-21
[ [ "Meroni", "A.", "" ], [ "Molinaro", "E.", "" ], [ "Petcov", "S. T.", "" ] ]
We investigate the generation of the baryon asymmetry of the Universe within a SUSY SU(5) x T' model of flavour, which gives rise to realistic masses and mixing patterns for quarks and leptons. The model employs the see-saw mechanism for generation of the light neutrino masses and the baryon asymmetry is produced via leptogenesis. We perform detailed calculations of both the CP violating lepton asymmetries, originating from the decays of the heavy Majorana neutrinos operative in the see-saw mechanism, and of the efficiency factors which account for the lepton asymmetry wash-out processes in the Early Universe. The latter are calculated by solving numerically the system of Boltzmann equations describing the generation and the evolution of the lepton asymmetries. The baryon asymmetry in the model considered is proportional to the J_{CP} factor, which determines the magnitude of CP violation effects in the oscillations of flavour neutrinos. The leptogenesis scale can be sufficiently low, allowing to avoid the potential gravitino problem.
1303.1822
Jihn E. Kim
Jihn E. Kim
Natural Higgs-flavor-democracy solution of the mu problem of supersymmetry and the QCD axion
null
null
10.1103/PhysRevLett.111.031801
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the hierarchically small mu term in supersymmetric theories is a consequence of two identical pairs of Higgs doublets taking a democratic form for their mass matrix. We briefly discuss the discrete symmetry S2xS2 toward the democratic mass matrix. Then, we show that there results an approximate Peccei-Quinn symmetry and hence the value mu is related to the axion decay constant.
[ { "created": "Thu, 7 Mar 2013 21:00:06 GMT", "version": "v1" }, { "created": "Fri, 28 Jun 2013 06:07:58 GMT", "version": "v2" } ]
2017-03-22
[ [ "Kim", "Jihn E.", "" ] ]
We show that the hierarchically small mu term in supersymmetric theories is a consequence of two identical pairs of Higgs doublets taking a democratic form for their mass matrix. We briefly discuss the discrete symmetry S2xS2 toward the democratic mass matrix. Then, we show that there results an approximate Peccei-Quinn symmetry and hence the value mu is related to the axion decay constant.
hep-ph/0111044
Alessandro Drago
M.Anselmino, V.Barone, A.Drago and F.Murgia
Non-Standard Time Reversal for Particle Multiplets and the Spin-Flavor Structure of Hadrons
2 pages, proceedings of "The Spin Structure of the Proton", ECT - Trento, July 2001. Eds. S Bass, A De Roeck and A Deshpande
Nucl.Phys.Proc.Suppl. 105 (2002) 132-133
10.1016/S0920-5632(01)01967-3
null
hep-ph
null
We show that a system of quarks interacting with chiral fields provides a physical representation of a ``non-standard'' time reversal for particle multiplets proposed by Weinberg. As an application, we argue that, if the internal structure of hadrons is described by a chiral lagrangian, the so-called time-reversal-odd quark distribution functions might not be forbidden by time-reversal invariance.
[ { "created": "Mon, 5 Nov 2001 18:34:59 GMT", "version": "v1" } ]
2009-11-07
[ [ "Anselmino", "M.", "" ], [ "Barone", "V.", "" ], [ "Drago", "A.", "" ], [ "Murgia", "F.", "" ] ]
We show that a system of quarks interacting with chiral fields provides a physical representation of a ``non-standard'' time reversal for particle multiplets proposed by Weinberg. As an application, we argue that, if the internal structure of hadrons is described by a chiral lagrangian, the so-called time-reversal-odd quark distribution functions might not be forbidden by time-reversal invariance.
1205.6628
Ulf-G. Mei{\ss}ner
I. T. Lorenz, H.-W. Hammer, Ulf-G. Mei{\ss}ner
The size of the proton - closing in on the radius puzzle
4 pages, 2 figures, fit improved, small modifications, section on continued fractions modified, conclusions on the proton charge radius unchanged, version accepted for publication in European Physical Journal A
Eur. Phys. J. A, 48 11 (2012) 151
10.1140/epja/i2012-12151-1
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the recent electron-proton scattering data from Mainz using a dispersive framework that respects the constraints from analyticity and unitarity on the nucleon structure. We also perform a continued fraction analysis of these data. We find a small electric proton charge radius, r_E^p = 0.84_{-0.01}^{+0.01} fm, consistent with the recent determination from muonic hydrogen measurements and earlier dispersive analyses. We also extract the proton magnetic radius, r_M^p = 0.86_{-0.03}^{+0.02} fm, consistent with earlier determinations based on dispersion relations.
[ { "created": "Wed, 30 May 2012 10:55:49 GMT", "version": "v1" }, { "created": "Mon, 29 Oct 2012 08:52:49 GMT", "version": "v2" } ]
2012-11-07
[ [ "Lorenz", "I. T.", "" ], [ "Hammer", "H. -W.", "" ], [ "Meißner", "Ulf-G.", "" ] ]
We analyze the recent electron-proton scattering data from Mainz using a dispersive framework that respects the constraints from analyticity and unitarity on the nucleon structure. We also perform a continued fraction analysis of these data. We find a small electric proton charge radius, r_E^p = 0.84_{-0.01}^{+0.01} fm, consistent with the recent determination from muonic hydrogen measurements and earlier dispersive analyses. We also extract the proton magnetic radius, r_M^p = 0.86_{-0.03}^{+0.02} fm, consistent with earlier determinations based on dispersion relations.
hep-ph/0103036
Zhang Zhao-xi
Chao-Hsi Chang, Yu-Qi Chen, Guo-Li Wang and Hong-Shi Zong
Decays of the Meson $B_c$ to a $P$-Wave Charmonium State $\chi_c$ or $h_c$
24 pages, 3 figures, the replacement for improving the presentation and adding references
Phys.Rev.D65:014017,2002
10.1103/PhysRevD.65.014017
null
hep-ph
null
The semileptonic decays, $B_{c}{\longrightarrow}{\chi_c}(h_c)+{\ell}+{{\nu}}_{\ell}$, and the two-body nonleptonic decays, $B_{c}{\longrightarrow}{\chi_c}(h_c)+h$, (here $\chi_c$ and $h_c$ denote $(c\bar c[^3P_J])$ and $(c\bar c[^1P_1])$ respectively, and $h$ indicates a meson) were computed. All of the form factors appearing in the relevant weak-current matrix elements with $B_c$ as its initial state and a $P$-wave charmonium state as its final state for the decays were precisely formulated in terms of two independent overlapping-integrations of the wave-functions of $B_c$ and the $P$-wave charmonium and with proper kinematics factors being `accompanied'. We found that the decays are quite sizable, so they may be accessible in Run-II at Tevatron and in the foreseen future at LHC, particularly, when BTeV and LHCB, the special detectors for B-physics, are borne in mind. In addition, we also pointed out that the decays $B_c\to h_c+...$ may potentially be used as a fresh window to look for the $h_c$ charmonium state, and the cascade decays, $B_c\to \chi_c[^3P_{1,2}]+l+\nu_l$ ($B_c\to \chi_c[^3P_{1,2}]+h$) with one of the radiative decays $\chi_c[^3P_{1,2}] \to J/\psi+\gamma$ being followed accordingly, may affect the observations of $B_c$ meson through the decays $B_{c}\to {J/\psi}+{l}+\nu_{l}$ ($B_c\to J/\psi+h$) substantially.
[ { "created": "Sat, 3 Mar 2001 10:45:01 GMT", "version": "v1" }, { "created": "Mon, 7 May 2001 03:43:00 GMT", "version": "v2" } ]
2011-03-23
[ [ "Chang", "Chao-Hsi", "" ], [ "Chen", "Yu-Qi", "" ], [ "Wang", "Guo-Li", "" ], [ "Zong", "Hong-Shi", "" ] ]
The semileptonic decays, $B_{c}{\longrightarrow}{\chi_c}(h_c)+{\ell}+{{\nu}}_{\ell}$, and the two-body nonleptonic decays, $B_{c}{\longrightarrow}{\chi_c}(h_c)+h$, (here $\chi_c$ and $h_c$ denote $(c\bar c[^3P_J])$ and $(c\bar c[^1P_1])$ respectively, and $h$ indicates a meson) were computed. All of the form factors appearing in the relevant weak-current matrix elements with $B_c$ as its initial state and a $P$-wave charmonium state as its final state for the decays were precisely formulated in terms of two independent overlapping-integrations of the wave-functions of $B_c$ and the $P$-wave charmonium and with proper kinematics factors being `accompanied'. We found that the decays are quite sizable, so they may be accessible in Run-II at Tevatron and in the foreseen future at LHC, particularly, when BTeV and LHCB, the special detectors for B-physics, are borne in mind. In addition, we also pointed out that the decays $B_c\to h_c+...$ may potentially be used as a fresh window to look for the $h_c$ charmonium state, and the cascade decays, $B_c\to \chi_c[^3P_{1,2}]+l+\nu_l$ ($B_c\to \chi_c[^3P_{1,2}]+h$) with one of the radiative decays $\chi_c[^3P_{1,2}] \to J/\psi+\gamma$ being followed accordingly, may affect the observations of $B_c$ meson through the decays $B_{c}\to {J/\psi}+{l}+\nu_{l}$ ($B_c\to J/\psi+h$) substantially.
1002.4538
Sylvie Flores
M. Martini (IPNL, Cea/Dam), M. Ericson (IPNL, CERN), G. Chanfray (IPNL), J. Marteau (IPNL)
Neutrino and antineutrino quasielastic interactions with nuclei
null
Physical Review C 81 (2010) 045502
10.1103/PhysRevC.81.045502
CERN-PH-TH/2010-046, LYCEN 2010-03
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the interaction of neutrinos and antineutrinos with nuclei. We explore in particular the role played by the multinucleon excitations which can contaminate the quasielastic cross section. For neutrinos the multinucleon term produces a sizable increase of the quasielastic cross section. Part of the effect arises from tensor correlations. For antineutrinos this influence is smaller owing to the axial-vector interference which increases the relative importance of the terms which are not affected by these multinucleon excitations.
[ { "created": "Wed, 24 Feb 2010 12:49:03 GMT", "version": "v1" } ]
2012-08-21
[ [ "Martini", "M.", "", "IPNL, Cea/Dam" ], [ "Ericson", "M.", "", "IPNL, CERN" ], [ "Chanfray", "G.", "", "IPNL" ], [ "Marteau", "J.", "", "IPNL" ] ]
We investigate the interaction of neutrinos and antineutrinos with nuclei. We explore in particular the role played by the multinucleon excitations which can contaminate the quasielastic cross section. For neutrinos the multinucleon term produces a sizable increase of the quasielastic cross section. Part of the effect arises from tensor correlations. For antineutrinos this influence is smaller owing to the axial-vector interference which increases the relative importance of the terms which are not affected by these multinucleon excitations.
hep-ph/0611201
Baier
V. N. Baier
Forty years of acting electron-positron colliders
32 pages, 5 figures
null
null
null
hep-ph
null
Around forty years passed from the beginning of operation of the first electron-positron colliding beam facility VEPP-2 in Institute of Nuclear Physics (INP), Novosibirsk. Here I described development of electron-positron colliding beam project in INP, as well as advance of similar projects of the first generation at LAL, Orsay and at LNF, Frascati.
[ { "created": "Wed, 15 Nov 2006 09:31:25 GMT", "version": "v1" } ]
2007-05-23
[ [ "Baier", "V. N.", "" ] ]
Around forty years passed from the beginning of operation of the first electron-positron colliding beam facility VEPP-2 in Institute of Nuclear Physics (INP), Novosibirsk. Here I described development of electron-positron colliding beam project in INP, as well as advance of similar projects of the first generation at LAL, Orsay and at LNF, Frascati.
hep-ph/9802295
Hiroshi Nunokawa
Hiroshi Nunokawa
Supernova Bounds on Neutrino Properties: a mini-review
Latex file, 8 pages, 11 ps figures, Talk given in Valencia 97: International Workshop on "Physics Beyond the Standard Model: from Theory to Experiment" Oct. 13-17, 1997, Valencia, Spain
null
null
FTUV/98-15, IFIC/98-15
hep-ph astro-ph
null
This talk summarizes our recent work which studied the impact of resonant neutrino conversion induced by some non-standard neutrino properties beyond mass and mixing, such as neutrino magnetic moment, lepton-flavor non-universality as well as flavor changing neutral current interactions in SUSY models with broken R parity, on supernova physics.
[ { "created": "Tue, 10 Feb 1998 23:04:35 GMT", "version": "v1" } ]
2007-05-23
[ [ "Nunokawa", "Hiroshi", "" ] ]
This talk summarizes our recent work which studied the impact of resonant neutrino conversion induced by some non-standard neutrino properties beyond mass and mixing, such as neutrino magnetic moment, lepton-flavor non-universality as well as flavor changing neutral current interactions in SUSY models with broken R parity, on supernova physics.
hep-ph/9805373
Apostolos Pilaftsis
Apostolos Pilaftsis (MPI, Munich)
Higgs Scalar-Pseudoscalar Mixing in the Minimal Supersymmetric Standard Model
17 pages, LaTeX, 3 encapsulated figures included
Phys.Lett.B435:88-100,1998
10.1016/S0370-2693(98)00771-0
MPI-PhT/98-38
hep-ph
null
In the minimal supersymmetric Standard Model, the heaviest CP-even Higgs boson H and the CP-odd Higgs scalar A are predicted to be almost degenerate in mass at the tree level, for the wide kinematic range M_A > 2M_Z and \tan\beta \ge 2. However, if large soft-CP-violating Yukawa interactions involving scalar quarks of the third generation are present in the theory, then the CP invariance of the Higgs potential can be maximally broken beyond the Born approximation, and the high degree of mass degeneracy between H and A may be lifted through a sizeable HA mixing. After taking the CP-odd tadpole renormalization of the A boson into account, we find that the small mass difference M_H - M_A, which is about 1% of the A-boson mass at the tree level, can be substantially enhanced to the 25% level at the one-loop order. We also find that the loop-induced mixing between the lightest CP-even Higgs boson h and the A boson may be of comparable size to M_h. We briefly discuss the main phenomenological implications of the predicted hA and HA mixings for the general Higgs-boson mass spectrum and for CP-violating observables at collider and lower energies.
[ { "created": "Tue, 19 May 1998 10:04:41 GMT", "version": "v1" } ]
2011-01-27
[ [ "Pilaftsis", "Apostolos", "", "MPI, Munich" ] ]
In the minimal supersymmetric Standard Model, the heaviest CP-even Higgs boson H and the CP-odd Higgs scalar A are predicted to be almost degenerate in mass at the tree level, for the wide kinematic range M_A > 2M_Z and \tan\beta \ge 2. However, if large soft-CP-violating Yukawa interactions involving scalar quarks of the third generation are present in the theory, then the CP invariance of the Higgs potential can be maximally broken beyond the Born approximation, and the high degree of mass degeneracy between H and A may be lifted through a sizeable HA mixing. After taking the CP-odd tadpole renormalization of the A boson into account, we find that the small mass difference M_H - M_A, which is about 1% of the A-boson mass at the tree level, can be substantially enhanced to the 25% level at the one-loop order. We also find that the loop-induced mixing between the lightest CP-even Higgs boson h and the A boson may be of comparable size to M_h. We briefly discuss the main phenomenological implications of the predicted hA and HA mixings for the general Higgs-boson mass spectrum and for CP-violating observables at collider and lower energies.
hep-ph/9806435
Kacper Zalewski
A. Bialas and K. Zalewski (Jagellonian University, Cracow, Poland)
Bose-Einstein condensation and independent production of pions
10 pages Latex, one figure as an EPS file
Phys.Lett. B436 (1998) 153-157
10.1016/S0370-2693(98)00837-5
null
hep-ph
null
The influence of the HBT effect on the momentum spectra of independently produced pions is studied using the method developed earlier for discussion of multiplicity distributions. It is shown that in this case all the spectra and multiparticle correlation functions are expressible in terms of one function of two momenta. It is also shown that at the critical point all pions are attracted into one quantum state and thus form a Bose-Einstein condensate.
[ { "created": "Mon, 22 Jun 1998 10:35:45 GMT", "version": "v1" } ]
2009-10-31
[ [ "Bialas", "A.", "", "Jagellonian University, Cracow, Poland" ], [ "Zalewski", "K.", "", "Jagellonian University, Cracow, Poland" ] ]
The influence of the HBT effect on the momentum spectra of independently produced pions is studied using the method developed earlier for discussion of multiplicity distributions. It is shown that in this case all the spectra and multiparticle correlation functions are expressible in terms of one function of two momenta. It is also shown that at the critical point all pions are attracted into one quantum state and thus form a Bose-Einstein condensate.
hep-ph/0403183
Stephen West
Thomas Hambye, John March-Russell, Stephen M. West
TeV scale resonant leptogenesis from supersymmetry breaking
10 Pages latex, version for JHEP
JHEP 0407 (2004) 070
10.1088/1126-6708/2004/07/070
OUTP-04/09
hep-ph
null
We propose a model of TeV-scale resonant leptogenesis based upon recent models of the generation of light neutrino masses from supersymmetry-breaking effects with TeV-scale right-handed (rhd) neutrinos, $N_i$. The model leads to naturally large cosmological lepton asymmetries via the resonant behaviour of the one-loop self-energy contribution to $N_i$ decay. Our model addresses the primary problems of previous phenomenological studies of low-energy leptogenesis: a rational for TeV-scale rhd neutrinos with small Yukawa couplings so that the out-of equilibrium condition for $N_i$ decay is satisfied; the origin of the tiny, but non-zero mass splitting required between at least two $N_i$ masses; and the necessary non-trivial breaking of flavour symmetries in the rhd neutrino sector. The low mass-scale of the rhd neutrinos and their superpartners, and the TeV-scale $A$-terms automatically contained within the model offer opportunities for partial direct experimental tests of this leptogenesis mechanism at future colliders.
[ { "created": "Tue, 16 Mar 2004 18:58:09 GMT", "version": "v1" }, { "created": "Thu, 2 Sep 2004 12:43:32 GMT", "version": "v2" } ]
2009-11-10
[ [ "Hambye", "Thomas", "" ], [ "March-Russell", "John", "" ], [ "West", "Stephen M.", "" ] ]
We propose a model of TeV-scale resonant leptogenesis based upon recent models of the generation of light neutrino masses from supersymmetry-breaking effects with TeV-scale right-handed (rhd) neutrinos, $N_i$. The model leads to naturally large cosmological lepton asymmetries via the resonant behaviour of the one-loop self-energy contribution to $N_i$ decay. Our model addresses the primary problems of previous phenomenological studies of low-energy leptogenesis: a rational for TeV-scale rhd neutrinos with small Yukawa couplings so that the out-of equilibrium condition for $N_i$ decay is satisfied; the origin of the tiny, but non-zero mass splitting required between at least two $N_i$ masses; and the necessary non-trivial breaking of flavour symmetries in the rhd neutrino sector. The low mass-scale of the rhd neutrinos and their superpartners, and the TeV-scale $A$-terms automatically contained within the model offer opportunities for partial direct experimental tests of this leptogenesis mechanism at future colliders.
1301.4965
Bruce Mellado
A. Djouadi, R.M. Godbole, B. Mellado and K. Mohan
Probing the spin-parity of the Higgs boson via jet kinematics in vector boson fusion
15 pages, 5 figures
Physics Letters B 723 (2013), pp. 307-313
10.1016/j.physletb.2013.04.060
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Determining the spin and the parity quantum numbers of the recently discovered Higgs-like boson at the LHC is a matter of great importance. In this paper, we consider the possibility of using the kinematics of the tagging jets in Higgs production via the vector boson fusion (VBF) process to test the tensor structure of the Higgs-vector boson ($HVV$) interaction and to determine the spin and CP properties of the observed resonance. We show that an anomalous $HVV$ vertex, in particular its explicit momentum dependence, drastically affects the rapidity between the two scattered quarks and their transverse momenta and, hence, the acceptance of the kinematical cuts that allow to select the VBF topology. The sensitivity of these observables to different spin-parity assignments, including the dependence on the LHC center of mass energy, are evaluated. In addition, we show that in associated Higgs production with a vector boson some kinematical variables, such as the invariant mass of the system and the transverse momenta of the two bosons and their separation in rapidity, are also sensitive to the spin--parity assignments of the Higgs--like boson.
[ { "created": "Mon, 21 Jan 2013 19:15:15 GMT", "version": "v1" }, { "created": "Mon, 10 Jun 2013 20:08:30 GMT", "version": "v2" } ]
2015-06-12
[ [ "Djouadi", "A.", "" ], [ "Godbole", "R. M.", "" ], [ "Mellado", "B.", "" ], [ "Mohan", "K.", "" ] ]
Determining the spin and the parity quantum numbers of the recently discovered Higgs-like boson at the LHC is a matter of great importance. In this paper, we consider the possibility of using the kinematics of the tagging jets in Higgs production via the vector boson fusion (VBF) process to test the tensor structure of the Higgs-vector boson ($HVV$) interaction and to determine the spin and CP properties of the observed resonance. We show that an anomalous $HVV$ vertex, in particular its explicit momentum dependence, drastically affects the rapidity between the two scattered quarks and their transverse momenta and, hence, the acceptance of the kinematical cuts that allow to select the VBF topology. The sensitivity of these observables to different spin-parity assignments, including the dependence on the LHC center of mass energy, are evaluated. In addition, we show that in associated Higgs production with a vector boson some kinematical variables, such as the invariant mass of the system and the transverse momenta of the two bosons and their separation in rapidity, are also sensitive to the spin--parity assignments of the Higgs--like boson.
hep-ph/9512279
null
D.V.Anchishkin, W.A.Zajc, G.M.Zinovjev
Coulomb Final State Interaction in Pion Interferometry for the Processes of High Multiplicity
9 pages, LaTeX file and 5 uuencoded gzipped PostScript figures (Fig. No.2 contains Fig.2a and Fig.2b)
null
null
Preprint University of Jyvaskyla, JYFL 14/95
hep-ph
null
The corrections for two pion correlations due to electromagnetic final state interactions at high secondary multiplicities are investigated. It is shown that these result in a noticeable deviation from the standard Gamov factor. This conclusion changes drastically in a model of the pion system with expansion. The critical parameter which determines the size of these effects is found to be the ratio of the relative velocity of detected pions to the velocity of the pair center-of-mass (in the fireball rest frame). In particular, when this parameter is much less than unity the pion pair escapes the initial high density region promptly and the distortion of the mutual Coulomb potential is weak.
[ { "created": "Mon, 11 Dec 1995 19:28:00 GMT", "version": "v1" }, { "created": "Tue, 12 Dec 1995 12:54:00 GMT", "version": "v2" } ]
2008-02-03
[ [ "Anchishkin", "D. V.", "" ], [ "Zajc", "W. A.", "" ], [ "Zinovjev", "G. M.", "" ] ]
The corrections for two pion correlations due to electromagnetic final state interactions at high secondary multiplicities are investigated. It is shown that these result in a noticeable deviation from the standard Gamov factor. This conclusion changes drastically in a model of the pion system with expansion. The critical parameter which determines the size of these effects is found to be the ratio of the relative velocity of detected pions to the velocity of the pair center-of-mass (in the fireball rest frame). In particular, when this parameter is much less than unity the pion pair escapes the initial high density region promptly and the distortion of the mutual Coulomb potential is weak.
0812.4092
Qiang Zhao
Qiang Zhao, Gang Li, and Chao-Hsi Chang
Further insights into the "$\rho\pi$ puzzle"
7 pages, 2 figures, proceeding of "The Conference on Interdisciplinary Fields of Particle Physics, Nuclear Physics and Cosmology", Aug. 2-4, 2008, Yunnan, China
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Based on a systematic investigation of $J/\psi(\psi^\prime)\to VP$, where $V$ and $P$ stand for light vector and pseudoscalar mesons, we identify the role played by the electromagnetic (EM) transitions and intermediate meson loop transitions, which are essential ingredients for understanding the $J/\psi$ and $\psi^\prime$ couplings to $VP$. We show that on the one hand, the EM transitions have relatively larger interferences in $\psi^\prime\to \rho\pi$ and $K^*\bar{K}+c.c.$ as explicitly shown by vector meson dominance (VMD). On the other hand, the strong decay of $\psi^\prime$ receives relatively larger destructive interferences from the intermediate meson loop transitions. By identifying these mechanisms in an overall study of $J/\psi(\psi^\prime)\to VP$, we provide a coherent understanding of the so-called "$\rho\pi$ puzzle".
[ { "created": "Mon, 22 Dec 2008 04:51:12 GMT", "version": "v1" } ]
2008-12-24
[ [ "Zhao", "Qiang", "" ], [ "Li", "Gang", "" ], [ "Chang", "Chao-Hsi", "" ] ]
Based on a systematic investigation of $J/\psi(\psi^\prime)\to VP$, where $V$ and $P$ stand for light vector and pseudoscalar mesons, we identify the role played by the electromagnetic (EM) transitions and intermediate meson loop transitions, which are essential ingredients for understanding the $J/\psi$ and $\psi^\prime$ couplings to $VP$. We show that on the one hand, the EM transitions have relatively larger interferences in $\psi^\prime\to \rho\pi$ and $K^*\bar{K}+c.c.$ as explicitly shown by vector meson dominance (VMD). On the other hand, the strong decay of $\psi^\prime$ receives relatively larger destructive interferences from the intermediate meson loop transitions. By identifying these mechanisms in an overall study of $J/\psi(\psi^\prime)\to VP$, we provide a coherent understanding of the so-called "$\rho\pi$ puzzle".
hep-ph/9604304
Jan Pisut
Jan Ftacnik (Bratislava),Jan Pisut (Clermont-Ferrand and Bratislava), Neva Pisutova (Bratislava)
Contribution of intermediate stage gluons to J/Psi suppression in Lead-Lead collisions at 158 AGeV
17 pp,Latex, 1 Table in Latex,1 Fig. in Latex, amended computations, conclusions unchanged, instead of "pre- equilibrium gluons" we refer to less ambiguous "intermediate stage gluons"
null
null
Revised version, Comenius University Bratislava, preprint
hep-ph
null
We point out that dissociation of J/Psi by partons (mostly gluons) present in the intermediate stage of heavy-ion collisions can explain J/Psi suppression observed recently by the NA-50 Collaboration at the CERN-SPS in Pb-Pb interactions. Suppression by intermediate stage gluons represents an additional multiplicative factor to that given by Gerschel-Hufner mechanism. The agreement with data on J/Psi suppression both in light- ions induced nuclear collisions and in Pb-Pb interactions requires that the life-time of intermediate gluons increases with nucleon numbers of colliding nuclei. In our model the energy density of intermediate stage gluons in Pb-Pb collisions approaches for a short time the critical density.
[ { "created": "Fri, 12 Apr 1996 13:28:41 GMT", "version": "v1" }, { "created": "Tue, 29 Oct 1996 22:03:57 GMT", "version": "v2" } ]
2016-09-01
[ [ "Ftacnik", "Jan", "", "Bratislava" ], [ "Pisut", "Jan", "", "Clermont-Ferrand and Bratislava" ], [ "Pisutova", "Neva", "", "Bratislava" ] ]
We point out that dissociation of J/Psi by partons (mostly gluons) present in the intermediate stage of heavy-ion collisions can explain J/Psi suppression observed recently by the NA-50 Collaboration at the CERN-SPS in Pb-Pb interactions. Suppression by intermediate stage gluons represents an additional multiplicative factor to that given by Gerschel-Hufner mechanism. The agreement with data on J/Psi suppression both in light- ions induced nuclear collisions and in Pb-Pb interactions requires that the life-time of intermediate gluons increases with nucleon numbers of colliding nuclei. In our model the energy density of intermediate stage gluons in Pb-Pb collisions approaches for a short time the critical density.
hep-ph/9906400
Shaouly Bar-Shalom
David Atwood, Shaouly Bar-Shalom, Amarjit Soni
Gauge Boson - Gauge Boson Scattering in Theories with Large Extra Dimensions
27 pages, plain latex, 7 figures embadded in the text using epsfig
Phys.Rev. D61 (2000) 054003
10.1103/PhysRevD.61.054003
UCRHEP-T258,BNL-HET-99/13
hep-ph
null
We consider the scattering amplitudes of the form V_1 V_2 -> V_3 V_4, where V_i=\gamma, Z, W or g(=gluon) are the Standard Model gauge bosons, due to graviton exchange in Kaluza-Klein theories with large extra dimensions. This leads to a number of experimentally viable signatures at high energy leptonic and hadronic colliders. We discuss the observability or future limits on the scale of the gravitational interactions (m_D), that may be obtained at an e+e- Next Linear Collider (NLC) and at the LHC, by studying some of these type of gauge boson scattering processes. We find that the attainable limits through these type of processes are: m_D > 3 TeV at the NLC and m_D > 6 TeV at the LHC.
[ { "created": "Wed, 16 Jun 1999 22:08:50 GMT", "version": "v1" }, { "created": "Thu, 20 Jan 2000 11:51:37 GMT", "version": "v2" } ]
2009-10-31
[ [ "Atwood", "David", "" ], [ "Bar-Shalom", "Shaouly", "" ], [ "Soni", "Amarjit", "" ] ]
We consider the scattering amplitudes of the form V_1 V_2 -> V_3 V_4, where V_i=\gamma, Z, W or g(=gluon) are the Standard Model gauge bosons, due to graviton exchange in Kaluza-Klein theories with large extra dimensions. This leads to a number of experimentally viable signatures at high energy leptonic and hadronic colliders. We discuss the observability or future limits on the scale of the gravitational interactions (m_D), that may be obtained at an e+e- Next Linear Collider (NLC) and at the LHC, by studying some of these type of gauge boson scattering processes. We find that the attainable limits through these type of processes are: m_D > 3 TeV at the NLC and m_D > 6 TeV at the LHC.
1802.06344
Eugene Levin
Carlos Contreras (UTFSM), Eugene Levin (Tel Aviv U,/UTFSM), Rodrigo Meneses (U.de Valparaiso) and Irina Potashnikova (UTFSM)
CGC/saturation approach: an impact-parameter dependent model for diffraction production in DIS
20pp. 14 figures in eps format
null
10.1140/epjc/s10052-018-5957-z
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the paper we discussed the evolution equations for diffractive production in the framework of CGC/saturation approach, and found the analytical solutions for several kinematic regions. The most impressive features of these solutions are, that diffractive production does not exibit geometric scaling behaviour i.e. being a function of one variable. Based on these solutions, we suggest an impact parameter dependent saturation model, which is suitable for describing diffraction production both deep in the saturation region, and in the vicinity of the saturation scale. Using the model we attempted to fit the combined data on diffraction production from H1 and ZEUS collaborations. We found that we are able describe both $x_\pom$ and $\beta$ dependence, as well as $Q$ behavior of the measured cross sections. In spite of the sufficiently large $\chi^2/d.o.f.$ we believe that our description provides an initial impetus to find a fit of the experimental data, based on the solution of the CGC/saturation equation, rather than on describing the diffraction system in simplistic manner, assuming that only quark-antiquark pair and one extra gluons, are produced.
[ { "created": "Sun, 18 Feb 2018 07:38:47 GMT", "version": "v1" } ]
2018-07-04
[ [ "Contreras", "Carlos", "", "UTFSM" ], [ "Levin", "Eugene", "", "Tel Aviv U,/UTFSM" ], [ "Meneses", "Rodrigo", "", "U.de Valparaiso" ], [ "Potashnikova", "Irina", "", "UTFSM" ] ]
In the paper we discussed the evolution equations for diffractive production in the framework of CGC/saturation approach, and found the analytical solutions for several kinematic regions. The most impressive features of these solutions are, that diffractive production does not exibit geometric scaling behaviour i.e. being a function of one variable. Based on these solutions, we suggest an impact parameter dependent saturation model, which is suitable for describing diffraction production both deep in the saturation region, and in the vicinity of the saturation scale. Using the model we attempted to fit the combined data on diffraction production from H1 and ZEUS collaborations. We found that we are able describe both $x_\pom$ and $\beta$ dependence, as well as $Q$ behavior of the measured cross sections. In spite of the sufficiently large $\chi^2/d.o.f.$ we believe that our description provides an initial impetus to find a fit of the experimental data, based on the solution of the CGC/saturation equation, rather than on describing the diffraction system in simplistic manner, assuming that only quark-antiquark pair and one extra gluons, are produced.
2407.21789
Elmar P. Biernat
Alfred Stadler, Elmar P. Biernat, Vasco Valverde
A simple high-accuracy method for solving bound-state equations with the Cornell potential in momentum space
null
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a simple, high-accuracy method for solving bound-state integral equations in momentum space with singular kernels. For the case of the linear-confining potential, the associated Cauchy-principal-value singularity is removed by subtraction. Derivatives of the wave function that appear as a result of the subtraction technique are approximated by means of interpolating functions. The resulting non-singular integral equation is solved using the Nystr\"om method. The results show excellent agreement with exactly known energy eigenvalues. By further increasing the number of integration points and the order of the Lagrange interpolation, results with extremely high accuracy can be achieved.
[ { "created": "Wed, 31 Jul 2024 17:57:43 GMT", "version": "v1" } ]
2024-08-01
[ [ "Stadler", "Alfred", "" ], [ "Biernat", "Elmar P.", "" ], [ "Valverde", "Vasco", "" ] ]
We present a simple, high-accuracy method for solving bound-state integral equations in momentum space with singular kernels. For the case of the linear-confining potential, the associated Cauchy-principal-value singularity is removed by subtraction. Derivatives of the wave function that appear as a result of the subtraction technique are approximated by means of interpolating functions. The resulting non-singular integral equation is solved using the Nystr\"om method. The results show excellent agreement with exactly known energy eigenvalues. By further increasing the number of integration points and the order of the Lagrange interpolation, results with extremely high accuracy can be achieved.
hep-ph/0408053
Andrea Banfi
Andrea Banfi
Dijet rates with symmetric cuts
4 pages, 1 figure; talk presented at DIS 2004, Strbske Pleso, Slovakia, April 2004
null
null
NIKHEF-2004-009
hep-ph
null
We show that a resummation of infrared logarithms is needed to obtain a sensible theoretical description of dijet rates when symmetric cuts are applied to the transverse energies of both jets. We also present the next-to-leading logarithmic (NLL) resummation we carried out for DIS production of two jets selected with the cone algorithm.
[ { "created": "Wed, 4 Aug 2004 12:45:04 GMT", "version": "v1" } ]
2007-05-23
[ [ "Banfi", "Andrea", "" ] ]
We show that a resummation of infrared logarithms is needed to obtain a sensible theoretical description of dijet rates when symmetric cuts are applied to the transverse energies of both jets. We also present the next-to-leading logarithmic (NLL) resummation we carried out for DIS production of two jets selected with the cone algorithm.
1805.12533
Jos\'e Francisco Zurita
David Curtin, Kaustubh Deshpande, Oliver Fischer and Jose Zurita
Probing BSM physics with electron-proton colliders
5 pages, 3 figures, talk at the 26th International Workshop on Deep-Inelastic Scattering and Related Topics (DIS 2018)
null
null
TTP18-025
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk I will illustrate with two examples (Higgsino dark matter and Exotic Higgs decays) how electron-proton colliders present unique opportunities to probe BSM scenarios where proton-proton colliders fall short due to the experimental difficulties in reconstructing the signal due to the large hadronic backgrounds. The leit-motiv of these examples are long-lived particles (LLPs), which have received recently a lot of attention from both the experimental and theoretical communities. We find that the proposed $e^-p$ colliders can be competitive against their more energetic $pp$ incarnations for lifetimes between a millimeter and a micron, depending on the physics scenario under consideration.
[ { "created": "Thu, 31 May 2018 16:07:44 GMT", "version": "v1" }, { "created": "Wed, 4 Jul 2018 14:13:44 GMT", "version": "v2" } ]
2018-07-05
[ [ "Curtin", "David", "" ], [ "Deshpande", "Kaustubh", "" ], [ "Fischer", "Oliver", "" ], [ "Zurita", "Jose", "" ] ]
In this talk I will illustrate with two examples (Higgsino dark matter and Exotic Higgs decays) how electron-proton colliders present unique opportunities to probe BSM scenarios where proton-proton colliders fall short due to the experimental difficulties in reconstructing the signal due to the large hadronic backgrounds. The leit-motiv of these examples are long-lived particles (LLPs), which have received recently a lot of attention from both the experimental and theoretical communities. We find that the proposed $e^-p$ colliders can be competitive against their more energetic $pp$ incarnations for lifetimes between a millimeter and a micron, depending on the physics scenario under consideration.
1111.0516
Vladimir Zoller
R. Fiore and V. R. Zoller
UHE Neutrinos: Fusing gluons within diffraction cone
6 pages, 2 figures, Talk at the "Low-x" meeting, 2-7 June 2011 Santiago de Compostela
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Currently available estimates of the gluon-fusion effect in ultra-high energy neutrino-nucleon interactions as well as in DIS on protons suffer from uncertainty in defining the scattering profile function $\Gamma(b)$. Indeed, the area, $S$, in the impact parameter space populated with interacting gluons varies by a factor of $4 - 5$ from one analysis to another. To get rid of uncertainties we specify the dipole-nucleon partial-wave amplitude $\Gamma(b)$ which meets the restrictions imposed by both the total dipole-nucleon cross section and the small angle elastic scattering amplitude. The area $S$ becomes a well defined quantity proportional to the diffraction cone slope. We solve numerically the non-linear color dipole BFKL equation and evaluate the UHE neutrino-nucleon total cross section. Our finding is that the saturation is a rather weak effect, $\lsim 25%$, up to $E_{\nu}\sim 10^{12}$ GeV.
[ { "created": "Wed, 2 Nov 2011 14:38:38 GMT", "version": "v1" } ]
2011-11-03
[ [ "Fiore", "R.", "" ], [ "Zoller", "V. R.", "" ] ]
Currently available estimates of the gluon-fusion effect in ultra-high energy neutrino-nucleon interactions as well as in DIS on protons suffer from uncertainty in defining the scattering profile function $\Gamma(b)$. Indeed, the area, $S$, in the impact parameter space populated with interacting gluons varies by a factor of $4 - 5$ from one analysis to another. To get rid of uncertainties we specify the dipole-nucleon partial-wave amplitude $\Gamma(b)$ which meets the restrictions imposed by both the total dipole-nucleon cross section and the small angle elastic scattering amplitude. The area $S$ becomes a well defined quantity proportional to the diffraction cone slope. We solve numerically the non-linear color dipole BFKL equation and evaluate the UHE neutrino-nucleon total cross section. Our finding is that the saturation is a rather weak effect, $\lsim 25%$, up to $E_{\nu}\sim 10^{12}$ GeV.
1211.7165
Helen Matskevich
S. M. Gerasyuta and E. E. Matskevich
Low-lying hypernuclei in the relativistic quark-gluon model
8 pages. arXiv admin note: substantial text overlap with arXiv:1211.0667; and text overlap with arXiv:1206.5219 by other authors
null
10.1103/PhysRevD.87.116006
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Low-lying hypernuclei $ ^3_{\Lambda}H$, $ ^3_{\Sigma}H$, $ ^3_{\Lambda}He$, $ ^3_{\Sigma}He$ are described by the relativistic nine-quark equations in the framework of the dispersion relation technique. The approximate solutions of these equations using the method based on the extraction of leading singularities of the amplitudes are obtained. The relativistic nine-quark amplitudes of hypernuclei, including the quarks of three flavors ($u$, $d$, $s$) are calculated. The poles of these amplitudes determine the masses of hypernuclei. The mass of state $ ^3_{\Lambda}H$ with the isospin I=0 and the spin-parity $J^P=\frac{1}{2}^+$ is equal to $M=2991\, MeV$.
[ { "created": "Fri, 30 Nov 2012 07:10:20 GMT", "version": "v1" }, { "created": "Wed, 6 Mar 2013 06:45:53 GMT", "version": "v2" } ]
2015-06-12
[ [ "Gerasyuta", "S. M.", "" ], [ "Matskevich", "E. E.", "" ] ]
Low-lying hypernuclei $ ^3_{\Lambda}H$, $ ^3_{\Sigma}H$, $ ^3_{\Lambda}He$, $ ^3_{\Sigma}He$ are described by the relativistic nine-quark equations in the framework of the dispersion relation technique. The approximate solutions of these equations using the method based on the extraction of leading singularities of the amplitudes are obtained. The relativistic nine-quark amplitudes of hypernuclei, including the quarks of three flavors ($u$, $d$, $s$) are calculated. The poles of these amplitudes determine the masses of hypernuclei. The mass of state $ ^3_{\Lambda}H$ with the isospin I=0 and the spin-parity $J^P=\frac{1}{2}^+$ is equal to $M=2991\, MeV$.
hep-ph/0102099
Alexander Studenikin
M. Dvornikov, A.Studenikin
Parametric Resonance of Neutrino Oscillations in Electromagnetic Wave
The enlarged version of contribution to the Proceedings of the Third International Workshop on New Worlds in Astroparticle Physics (Faro, 2000)
null
10.1142/9789812811035_0012
null
hep-ph
null
Within the Lorentz invariant formalizm for description of neutrino evolution in electromagnetic fields and matter we consider neutrino spin oscillations in the circular polarized electromagnetic wave, the amplitude of which is a modulated function of time. It is shown for the first time that the parametric resonance of neutrino oscillations can occur in such a system.
[ { "created": "Thu, 8 Feb 2001 15:45:50 GMT", "version": "v1" }, { "created": "Fri, 16 Feb 2001 15:21:55 GMT", "version": "v2" }, { "created": "Tue, 10 Apr 2001 13:41:43 GMT", "version": "v3" } ]
2016-11-03
[ [ "Dvornikov", "M.", "" ], [ "Studenikin", "A.", "" ] ]
Within the Lorentz invariant formalizm for description of neutrino evolution in electromagnetic fields and matter we consider neutrino spin oscillations in the circular polarized electromagnetic wave, the amplitude of which is a modulated function of time. It is shown for the first time that the parametric resonance of neutrino oscillations can occur in such a system.
hep-ph/9412390
W. S. Hou
Wei-Shu Hou and Gwo-Guang Wong
Perspective on Quark Mass and Mixing Relations
10 pages, ReVtex, no figures
Phys.Rev.D52:5269-5272,1995
10.1103/PhysRevD.52.5269
NTUTH-94-21
hep-ph
null
Recent data indicate that $V_{ub}\cong \lambda^4 \cong (0.22)^4$, while $m_t$ seems to be $174$ GeV. The relations $m_d/m_s\sim m_s/m_b \sim \delta \sim \lambda^2 \simeq \vert V_{cb}\vert$ and $m_u/m_c\sim m_c/m_t \sim \delta^2 \sim \lambda^4 \sim \vert V_{ub}\vert$ suggest that %a plausible clean separation of the %origin of the quark mixing matrix: the down type sector is responsible for $\vert V_{us}\vert$ and $\vert V_{cb}\vert$, while $V_{ub}$ comes from the up type sector. Five to six parameters might suffice to account for the ten quark mass and mixing parameters, resulting in specific power series representations for the mass matrices. In this picture, $\delta$ seems to be the more sensible expansion parameter, while $\lambda \cong \sqrt{m_d/m_s} \sim \sqrt{\delta}$ is tied empirically to $(M_d)_{11} = 0$.
[ { "created": "Sat, 31 Dec 1994 01:09:16 GMT", "version": "v1" } ]
2010-11-01
[ [ "Hou", "Wei-Shu", "" ], [ "Wong", "Gwo-Guang", "" ] ]
Recent data indicate that $V_{ub}\cong \lambda^4 \cong (0.22)^4$, while $m_t$ seems to be $174$ GeV. The relations $m_d/m_s\sim m_s/m_b \sim \delta \sim \lambda^2 \simeq \vert V_{cb}\vert$ and $m_u/m_c\sim m_c/m_t \sim \delta^2 \sim \lambda^4 \sim \vert V_{ub}\vert$ suggest that %a plausible clean separation of the %origin of the quark mixing matrix: the down type sector is responsible for $\vert V_{us}\vert$ and $\vert V_{cb}\vert$, while $V_{ub}$ comes from the up type sector. Five to six parameters might suffice to account for the ten quark mass and mixing parameters, resulting in specific power series representations for the mass matrices. In this picture, $\delta$ seems to be the more sensible expansion parameter, while $\lambda \cong \sqrt{m_d/m_s} \sim \sqrt{\delta}$ is tied empirically to $(M_d)_{11} = 0$.
0708.2905
Roman Nevzorov
C.D. Froggatt, R. Nevzorov, H.B. Nielsen
Enhanced Higgs boson production and avoidance of CP-violation and FCNC in the MPP inspired 2HDM
Talk given at the 2007 Europhysics Conference on High Energy Physics, Manchester, England, 19-25 July 2007, CERN preprint number added, references updated
J.Phys.Conf.Ser.110:062010,2008
10.1088/1742-6596/110/6/062010
CERN-PH-TH/2007-193
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The multiple point principle (MPP) can be used to suppress non--diagonal flavour transitions and CP violation in the two Higgs doublet extension of the standard model. We discuss the quasi--fixed point scenario in the MPP inspired two Higgs doublet model which leads to the enhanced production of Higgs particles at the LHC if the MPP scale is low.
[ { "created": "Tue, 21 Aug 2007 19:42:45 GMT", "version": "v1" }, { "created": "Tue, 21 Aug 2007 20:02:36 GMT", "version": "v2" }, { "created": "Thu, 19 Jun 2008 18:58:31 GMT", "version": "v3" } ]
2008-11-26
[ [ "Froggatt", "C. D.", "" ], [ "Nevzorov", "R.", "" ], [ "Nielsen", "H. B.", "" ] ]
The multiple point principle (MPP) can be used to suppress non--diagonal flavour transitions and CP violation in the two Higgs doublet extension of the standard model. We discuss the quasi--fixed point scenario in the MPP inspired two Higgs doublet model which leads to the enhanced production of Higgs particles at the LHC if the MPP scale is low.
hep-ph/0612191
Robert D. Pisarski
Robert D. Pisarski
Fuzzy Bags and Wilson Lines
9 pages, 2 figures, PTPTeX. Based upon a talk given at Yukawa International Seminar (YKIS) 2006, ``New Frontiers in QCD -- Exotic Hadrons and Hadronic Matter''
Prog.Theor.Phys.Suppl.168:276-284,2007
10.1143/PTPS.168.276
null
hep-ph
null
I start with an elementary observation about the pressure in the deconfined phase of a SU(3) gauge theory without quarks. This suggests a ``fuzzy'' bag model for the analogous pressure in QCD, with dynamical quarks. I then sketch how the deconfined phase might be described using an effective theory of Wilson lines. To leading order in weak coupling, the effective electric field appears in a form familiar from the lattice theory of Banks and Ukawa.
[ { "created": "Fri, 15 Dec 2006 12:33:01 GMT", "version": "v1" } ]
2008-11-26
[ [ "Pisarski", "Robert D.", "" ] ]
I start with an elementary observation about the pressure in the deconfined phase of a SU(3) gauge theory without quarks. This suggests a ``fuzzy'' bag model for the analogous pressure in QCD, with dynamical quarks. I then sketch how the deconfined phase might be described using an effective theory of Wilson lines. To leading order in weak coupling, the effective electric field appears in a form familiar from the lattice theory of Banks and Ukawa.
1211.3052
C\'edric Weiland
A. Abada, D. Das, A.M. Teixeira, A. Vicente and C. Weiland
Tree-level lepton universality violation in the presence of sterile neutrinos: impact for $R_K$ and $R_\pi$
9 pages, 2 eps figures
null
10.1007/JHEP02(2013)048
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a tree-level enhancement to the violation of lepton flavour universality in light meson decays arising from modified $W \ell \nu$ couplings in the standard model minimally extended by sterile neutrinos. Due to the presence of additional mixings between the active (left-handed) neutrinos and the new sterile states, the deviation from unitarity of the leptonic mixing matrix intervening in charged currents might lead to a tree-level enhancement of $R_{P} = \Gamma (P \to e \nu) / \Gamma (P \to \mu \nu)$, with $P=K, \pi$. We illustrate these enhancements in the case of the inverse seesaw model, showing that one can saturate the current experimental bounds on $\Delta r_{K}$ (and $\Delta r_{\pi}$), while in agreement with the different experimental and observational constraints.
[ { "created": "Tue, 13 Nov 2012 17:09:48 GMT", "version": "v1" }, { "created": "Sun, 25 Nov 2012 18:20:07 GMT", "version": "v2" } ]
2015-06-12
[ [ "Abada", "A.", "" ], [ "Das", "D.", "" ], [ "Teixeira", "A. M.", "" ], [ "Vicente", "A.", "" ], [ "Weiland", "C.", "" ] ]
We consider a tree-level enhancement to the violation of lepton flavour universality in light meson decays arising from modified $W \ell \nu$ couplings in the standard model minimally extended by sterile neutrinos. Due to the presence of additional mixings between the active (left-handed) neutrinos and the new sterile states, the deviation from unitarity of the leptonic mixing matrix intervening in charged currents might lead to a tree-level enhancement of $R_{P} = \Gamma (P \to e \nu) / \Gamma (P \to \mu \nu)$, with $P=K, \pi$. We illustrate these enhancements in the case of the inverse seesaw model, showing that one can saturate the current experimental bounds on $\Delta r_{K}$ (and $\Delta r_{\pi}$), while in agreement with the different experimental and observational constraints.
1606.00476
Erez Raicher
Erez Raicher, Shalom Eliezer, and Arie Zigler
Non-Linear Compton Scattering in a Strong Rotating Electric Field
17 pages, 9 figures
Phys. Rev. A 94, 062105 (2016)
10.1103/PhysRevA.94.062105
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The non-linear Compton scattering rate in a rotating electric field is explicitly calculated for the first time. For this purpose, a novel solution to the Klein-Gordon equation in the presence of a rotating electric field is applied. An analytical expression for the emission rate is obtained, as well as a simplified approximation adequate for emplementation in kinetic codes. The spectrum is numerically calculated for nowadays optical and X-ray laser parameters. The results are compared to the standard Volkov-Ritus rate for a particle in a plane wave, which is commonly assumed to be valid for a rotating electric field under certain conditions. Subsequent deviations between the two models, both in the radiated power and the spectral shape, are demonstrated. First, the typical number of photons participating in the scattering process is much smaller compared to the Volkov-Ritus rate, resulting in up to an order of magnitude lower emitted power. Furthermore, our model predicts a discrete harmonics spectrum for electrons with low asymptotic momentum compared to the field amplitude. This discrete structure is a clear imprint of the electric field frequency, as opposed to the Volkov-Ritus rate which reduces to the constant crossed field rate for the physical conditions under consideration. Our model predictions can be tested with present-days laser facilities.
[ { "created": "Wed, 1 Jun 2016 21:29:49 GMT", "version": "v1" } ]
2016-12-14
[ [ "Raicher", "Erez", "" ], [ "Eliezer", "Shalom", "" ], [ "Zigler", "Arie", "" ] ]
The non-linear Compton scattering rate in a rotating electric field is explicitly calculated for the first time. For this purpose, a novel solution to the Klein-Gordon equation in the presence of a rotating electric field is applied. An analytical expression for the emission rate is obtained, as well as a simplified approximation adequate for emplementation in kinetic codes. The spectrum is numerically calculated for nowadays optical and X-ray laser parameters. The results are compared to the standard Volkov-Ritus rate for a particle in a plane wave, which is commonly assumed to be valid for a rotating electric field under certain conditions. Subsequent deviations between the two models, both in the radiated power and the spectral shape, are demonstrated. First, the typical number of photons participating in the scattering process is much smaller compared to the Volkov-Ritus rate, resulting in up to an order of magnitude lower emitted power. Furthermore, our model predicts a discrete harmonics spectrum for electrons with low asymptotic momentum compared to the field amplitude. This discrete structure is a clear imprint of the electric field frequency, as opposed to the Volkov-Ritus rate which reduces to the constant crossed field rate for the physical conditions under consideration. Our model predictions can be tested with present-days laser facilities.
hep-ph/9302221
Bruce Campbell
B.A. Campbell, S. Davidson, J. Ellis, And K.A. Olive
On the Baryon, Lepton-Flavour and Right-Handed Electron Asymmetries of the Universe
LATEX File with 12 pages, one figure (not included); published in Phys. Lett B297 (1992) p118
Phys.Lett.B297:118-124,1992
10.1016/0370-2693(92)91079-O
null
hep-ph
null
Non-perturbative electroweak effects, in thermal equilibrium in the early universe, have the potential to erase the baryon asymmetry of the universe, unless it is encoded in a B-L asymmetry, or in some "accidentally" conserved quantity. We first consider the possibility that the BAU may be regenerated from lepton flavour asymmetries even when initially $B-L = 0$. We show that provided some, but {\it not} all the lepton flavours are violated by ${\Delta}L{\neq}0$ interactions in equilibrium, the BAU may be regenerated without lepton mass effects. We next examine the possibility of encoding the baryon asymmetry in a primordial asymmetry for the right-handed electron, which due to its weak Yukawa interaction only comes into chemical equilibrium as the sphalerons are falling out of equilibrium. This would also raise the possibility of preserving an initial baryon asymmetry when $B-L = 0$.
[ { "created": "Fri, 5 Feb 1993 02:11:58 GMT", "version": "v1" } ]
2009-09-11
[ [ "Campbell", "B. A.", "" ], [ "Davidson", "S.", "" ], [ "Ellis", "J.", "" ], [ "Olive", "And K. A.", "" ] ]
Non-perturbative electroweak effects, in thermal equilibrium in the early universe, have the potential to erase the baryon asymmetry of the universe, unless it is encoded in a B-L asymmetry, or in some "accidentally" conserved quantity. We first consider the possibility that the BAU may be regenerated from lepton flavour asymmetries even when initially $B-L = 0$. We show that provided some, but {\it not} all the lepton flavours are violated by ${\Delta}L{\neq}0$ interactions in equilibrium, the BAU may be regenerated without lepton mass effects. We next examine the possibility of encoding the baryon asymmetry in a primordial asymmetry for the right-handed electron, which due to its weak Yukawa interaction only comes into chemical equilibrium as the sphalerons are falling out of equilibrium. This would also raise the possibility of preserving an initial baryon asymmetry when $B-L = 0$.
hep-ph/0305018
Masafumi Kurachi
Masayasu Harada, Masafumi Kurachi and Koichi Yamawaki
Meson masses in large Nf QCD from the Bethe-Salpeter equation
33 pages, 16 figures. Typos are corrected. Minor corrections and references are added. Version to appear in Phys. Rev. D
Phys.Rev. D68 (2003) 076001
10.1103/PhysRevD.68.076001
DPNU-03-09
hep-ph
null
We solve the homogeneous Bethe-Salpeter (HBS) equation for the scalar, pseudoscalar, vector, and axial-vector bound states of quark and anti-quark in large Nf QCD with the improved ladder approximation in the Landau gauge. The quark mass function in the HBS equation is obtained from the Schwinger-Dyson (SD) equation in the same approximation for consistency with the chiral symmetry. Amazingly, due to the fact that the two-loop running coupling of large Nf QCD is explicitly written in terms of an analytic function, large Nf QCD turns out to be the first example in which the SD equation can be solved in the complex plane and hence the HBS equation directly in the time-like region. We find that approaching the chiral phase transition point from the broken phase, the scalar, vector, and axial-vector meson masses vanish to zero with the same scaling behavior, all degenerate with the massless pseudoscalar meson. This may suggest a new type of manifestation of the chiral symmetry restoration in large Nf QCD.
[ { "created": "Fri, 2 May 2003 11:00:28 GMT", "version": "v1" }, { "created": "Wed, 24 Sep 2003 10:45:57 GMT", "version": "v2" } ]
2009-11-10
[ [ "Harada", "Masayasu", "" ], [ "Kurachi", "Masafumi", "" ], [ "Yamawaki", "Koichi", "" ] ]
We solve the homogeneous Bethe-Salpeter (HBS) equation for the scalar, pseudoscalar, vector, and axial-vector bound states of quark and anti-quark in large Nf QCD with the improved ladder approximation in the Landau gauge. The quark mass function in the HBS equation is obtained from the Schwinger-Dyson (SD) equation in the same approximation for consistency with the chiral symmetry. Amazingly, due to the fact that the two-loop running coupling of large Nf QCD is explicitly written in terms of an analytic function, large Nf QCD turns out to be the first example in which the SD equation can be solved in the complex plane and hence the HBS equation directly in the time-like region. We find that approaching the chiral phase transition point from the broken phase, the scalar, vector, and axial-vector meson masses vanish to zero with the same scaling behavior, all degenerate with the massless pseudoscalar meson. This may suggest a new type of manifestation of the chiral symmetry restoration in large Nf QCD.
1904.06732
Alexander Berezhnoy
A. V. Berezhnoy, I. N. Belov, A. K. Likhoded, and A. V. Luchinsky
$B_c$ excitations at LHC experiments
18 pages, 4 figures, typos fixed, two figures with Bc(P) decays changed
Mod. Phys. Lett. A. 34 (2019) 1950331
10.1142/S0217732319503310
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The $2S$ $B_c$ states observed by ATLAS, CMS and LHCb Collaborations are discussed. The observation perspectives of $B_c^*$, $2P$ wave, $3P$ wave and $D$ wave states of $B_c$ at LHC experiments are estimated.
[ { "created": "Sun, 14 Apr 2019 17:54:29 GMT", "version": "v1" }, { "created": "Wed, 15 May 2019 20:32:14 GMT", "version": "v2" } ]
2019-09-17
[ [ "Berezhnoy", "A. V.", "" ], [ "Belov", "I. N.", "" ], [ "Likhoded", "A. K.", "" ], [ "Luchinsky", "A. V.", "" ] ]
The $2S$ $B_c$ states observed by ATLAS, CMS and LHCb Collaborations are discussed. The observation perspectives of $B_c^*$, $2P$ wave, $3P$ wave and $D$ wave states of $B_c$ at LHC experiments are estimated.
hep-ph/9411346
Anna Jadczyk
Ludwik Turko
Hadronic Matter with Internal Symmetries and its Consequences: An Expanding Hadronic Gas
7 pages, 2 figures - uucoded file of figures appended at the end, separated from the paper by lines with many dashes
null
null
null
hep-ph
null
We consider an ideal gas of massive hadrons in thermal and chemical equilibrium. The gas expands longitudinally in accordance with Bjorken law. Strangeness and baryon number conservation is taken into account. This gas has different features as compared to the pion gas.
[ { "created": "Mon, 21 Nov 1994 10:44:56 GMT", "version": "v1" } ]
2009-09-25
[ [ "Turko", "Ludwik", "" ] ]
We consider an ideal gas of massive hadrons in thermal and chemical equilibrium. The gas expands longitudinally in accordance with Bjorken law. Strangeness and baryon number conservation is taken into account. This gas has different features as compared to the pion gas.
2309.16236
Sam Van Thurenhout
S. Van Thurenhout
Basis transformation properties of anomalous dimensions for hard exclusive processes
39 pages, LaTeX, 2 figures, journal version
Nucl.Phys.B 1000 (2024) 116464
10.1016/j.nuclphysb.2024.116464
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
When considering the renormalization of composite operators for the description of hard exclusive scattering processes, two types of operator basis called the derivative basis and the Gegenbauer basis are often used in the literature. In this work we set up the explicit similarity transformations between these two bases, both for quark and gluon operators. This way, one can use the properties of both bases to their advantage in the computation of the operator anomalous dimensions, which describe the scale dependence of non-perturbative non-forward parton distributions. We provide several applications of our framework. As an application of the gluon transformation formula, we compute the one-loop non-forward purely gluonic anomalous dimension matrix. For the rest of the applications we focus on the transformation formula of the quark operator. We derive the Gegenbauer anomalous dimensions, in the limit of a large number of quark flavors $n_f$, to all orders in the strong coupling $\alpha_s$, extending the computation previously performed in the derivative basis. Next a numeric calculation of the two-loop anomalous dimensions in the derivative basis beyond the leading-color limit is presented. Finally, we discuss a novel way of validating existing computations of the conformal anomaly based on the leading-color anomalous dimensions in the derivative basis.
[ { "created": "Thu, 28 Sep 2023 08:20:55 GMT", "version": "v1" }, { "created": "Wed, 14 Feb 2024 06:49:55 GMT", "version": "v2" } ]
2024-02-15
[ [ "Van Thurenhout", "S.", "" ] ]
When considering the renormalization of composite operators for the description of hard exclusive scattering processes, two types of operator basis called the derivative basis and the Gegenbauer basis are often used in the literature. In this work we set up the explicit similarity transformations between these two bases, both for quark and gluon operators. This way, one can use the properties of both bases to their advantage in the computation of the operator anomalous dimensions, which describe the scale dependence of non-perturbative non-forward parton distributions. We provide several applications of our framework. As an application of the gluon transformation formula, we compute the one-loop non-forward purely gluonic anomalous dimension matrix. For the rest of the applications we focus on the transformation formula of the quark operator. We derive the Gegenbauer anomalous dimensions, in the limit of a large number of quark flavors $n_f$, to all orders in the strong coupling $\alpha_s$, extending the computation previously performed in the derivative basis. Next a numeric calculation of the two-loop anomalous dimensions in the derivative basis beyond the leading-color limit is presented. Finally, we discuss a novel way of validating existing computations of the conformal anomaly based on the leading-color anomalous dimensions in the derivative basis.
hep-ph/0701193
Rohini Godbole Professor
Rohini M. Godbole
Moderately light charged Higgs in \cp MSSM and NMSSM
LaTeX, six pages, four figures. Talk presented at the IPM School and Conference on Lepton Hadron Physics, Tehran, May 2006
ECONFC0605151:0016,2006
null
IISc-CHEP/2/07
hep-ph
null
In this talk I discuss some aspects of the phenomenology of a moderately light charged Higgs ($H^\pm$) with a mass $\gts 130$ GeV, lighter than the top quark, at the LHC. A charged Higgs in this mass range is still allowed in next-to-minimal Supersymmetric Standard Model (NMSSM) at low $\tan \beta$ as well as in CP-violating (\cp) Minimal Supersymmetric Standard Model (MSSM) for a certain choice of \cp parameters, still respecting all the LEP-II bounds. In both the cases, the $H^\pm$ has a large branching ratio in the $W^\pm \phi$ channel, where $\phi$ denotes a generic Higgs which is dominantly pseudoscalar and hence may be substantially lighter than the LEP-II mass bound. This $\phi$ decays dominantly into a $b \bar b$ pair. Thus production of $H^\pm$ in the top decay gives a striking $t \bar t$ signal at the LHC, where one of the top quarks decays into the $bb \bar b W$ channel, via $t \to b H^\pm, H^\pm \to \phi$ and $\phi \to b \bar b$. The characteristic correlation between the $b \bar b$, $b \bar b W$ and $b b \bar b W$ invariant mass peaks helps reduce the Standard Model (SM) background very effectively. For these low values of $\tan \beta$ the $H^\pm \to \tau \nu_\tau $ channel does not provide any reach for the $H^\pm$. Thus this is a signal for both a light charged $H^\pm$ and a light $\phi$, which is mostly pseudoscalar in nature and decays dominantly into a $b \bar b$ pair.
[ { "created": "Tue, 23 Jan 2007 15:58:06 GMT", "version": "v1" } ]
2008-11-26
[ [ "Godbole", "Rohini M.", "" ] ]
In this talk I discuss some aspects of the phenomenology of a moderately light charged Higgs ($H^\pm$) with a mass $\gts 130$ GeV, lighter than the top quark, at the LHC. A charged Higgs in this mass range is still allowed in next-to-minimal Supersymmetric Standard Model (NMSSM) at low $\tan \beta$ as well as in CP-violating (\cp) Minimal Supersymmetric Standard Model (MSSM) for a certain choice of \cp parameters, still respecting all the LEP-II bounds. In both the cases, the $H^\pm$ has a large branching ratio in the $W^\pm \phi$ channel, where $\phi$ denotes a generic Higgs which is dominantly pseudoscalar and hence may be substantially lighter than the LEP-II mass bound. This $\phi$ decays dominantly into a $b \bar b$ pair. Thus production of $H^\pm$ in the top decay gives a striking $t \bar t$ signal at the LHC, where one of the top quarks decays into the $bb \bar b W$ channel, via $t \to b H^\pm, H^\pm \to \phi$ and $\phi \to b \bar b$. The characteristic correlation between the $b \bar b$, $b \bar b W$ and $b b \bar b W$ invariant mass peaks helps reduce the Standard Model (SM) background very effectively. For these low values of $\tan \beta$ the $H^\pm \to \tau \nu_\tau $ channel does not provide any reach for the $H^\pm$. Thus this is a signal for both a light charged $H^\pm$ and a light $\phi$, which is mostly pseudoscalar in nature and decays dominantly into a $b \bar b$ pair.
0708.2588
Hong-Jian He
Hong-Jian He, Yu-Ping Kuang, Yong-Hui Qi, Bin Zhang (Tsinghua), Alexander Belyaev, R. Sekhar Chivukula, Neil D. Christensen, Alexander Pukhov, Elizabeth H. Simmons (MSU)
LHC Signatures of New Gauge Bosons in the Minimal Higgsless Model
5pp, Rapid Communication of PRD (in Press). Minor clarifications to stress the importance and broad interest of this work. (All results un-changed.)
Phys.Rev.D78:031701,2008
10.1103/PhysRevD.78.031701
TUHEP-TH-07162, MSUHEP-070817
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the LHC signatures of new gauge bosons in the gauge-invariant minimal Higgsless model. It predicts an extra pair of W_1 and Z_1 bosons which can be as light as ~400GeV and play a key role in the delay of unitarity violation. We analyze the W_1 signals in pp --> W_0Z_0Z_0 --> jj4\ell and pp --> jj W_0Z_0 --> jj3\ell\nu processes at the LHC, including the complete electroweak and QCD backgrounds. We reveal the complementarity between these two channels for discovering the W_1 boson, and demonstrate the LHC discovery potential over the full range of allowed W_1 mass.
[ { "created": "Mon, 20 Aug 2007 06:28:06 GMT", "version": "v1" }, { "created": "Tue, 1 Jul 2008 17:11:45 GMT", "version": "v2" } ]
2008-11-26
[ [ "He", "Hong-Jian", "", "Tsinghua" ], [ "Kuang", "Yu-Ping", "", "Tsinghua" ], [ "Qi", "Yong-Hui", "", "Tsinghua" ], [ "Zhang", "Bin", "", "Tsinghua" ], [ "Belyaev", "Alexander", "", "MSU" ], [ "Chivukula", "R. Sekhar", "", "MSU" ], [ "Christensen", "Neil D.", "", "MSU" ], [ "Pukhov", "Alexander", "", "MSU" ], [ "Simmons", "Elizabeth H.", "", "MSU" ] ]
We study the LHC signatures of new gauge bosons in the gauge-invariant minimal Higgsless model. It predicts an extra pair of W_1 and Z_1 bosons which can be as light as ~400GeV and play a key role in the delay of unitarity violation. We analyze the W_1 signals in pp --> W_0Z_0Z_0 --> jj4\ell and pp --> jj W_0Z_0 --> jj3\ell\nu processes at the LHC, including the complete electroweak and QCD backgrounds. We reveal the complementarity between these two channels for discovering the W_1 boson, and demonstrate the LHC discovery potential over the full range of allowed W_1 mass.
hep-ph/0105078
Daoneng Gao
Giancarlo D'Ambrosio and Dao-Neng Gao
The diquark model: New Physics effects for charm and kaon decays
LaTeX, 12 pages and 2 eps figures. Minor changes, paper accepted by Physics Letters B
Phys.Lett.B513:123-129,2001
10.1016/S0370-2693(01)00666-9
INFNNA-IV-2001/12, DSFNA-IV-2001/12
hep-ph
null
Motivated by diquark exchange, we construct a class of extensions of the standard model. These models can generate large CP conserving and CP violating contributions to the doubly Cabbibo suppressed decays D^0\to K^+\pi^- without affecting D^0-\overline{D^0} mixing, contrary to what is usually believed in the literature. We find an interesting specific realization of these models, which has the LR chiral structure and can induce novel density \times density operators. It is new for non-leptonic kaon decays, and particularly, may provide a possible solution to the \Delta I=1/2 rule and direct CP violation, without inducing large flavour changing neutral currents.
[ { "created": "Wed, 9 May 2001 17:49:40 GMT", "version": "v1" }, { "created": "Tue, 29 May 2001 08:43:11 GMT", "version": "v2" } ]
2014-11-17
[ [ "D'Ambrosio", "Giancarlo", "" ], [ "Gao", "Dao-Neng", "" ] ]
Motivated by diquark exchange, we construct a class of extensions of the standard model. These models can generate large CP conserving and CP violating contributions to the doubly Cabbibo suppressed decays D^0\to K^+\pi^- without affecting D^0-\overline{D^0} mixing, contrary to what is usually believed in the literature. We find an interesting specific realization of these models, which has the LR chiral structure and can induce novel density \times density operators. It is new for non-leptonic kaon decays, and particularly, may provide a possible solution to the \Delta I=1/2 rule and direct CP violation, without inducing large flavour changing neutral currents.
hep-ph/0310044
Enrique Ruiz Arriola
E. Ruiz Arriola (Departamento de Fisica Moderna, Universidad de Granada, Granada, Spain), Wojciech Broniowski (The H. Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Cracow, Poland)
The Spectral Quark Model and Light Cone Phenomenology
Talk Presented at "Light Cone Workshop: Hadrons and Beyond", 5th-9th August 2003, University of Durham (U.K.) 6 pages, 2 figures
null
null
null
hep-ph
null
Chiral quark models offer a practical and simple tool to describe covariantly both low and high energy phenomenology in combination with QCD evolution. This can be done in full harmony with chiral symmetry and electromagnetic gauge invariance. We review the recently proposed spectral quark model where all these constraints are implemented.
[ { "created": "Fri, 3 Oct 2003 08:53:49 GMT", "version": "v1" }, { "created": "Mon, 6 Oct 2003 07:47:21 GMT", "version": "v2" } ]
2007-05-23
[ [ "Arriola", "E. Ruiz", "", "Departamento de Fisica Moderna, Universidad de\n Granada, Granada, Spain" ], [ "Broniowski", "Wojciech", "", "The H. Niewodniczanski\n Institute of Nuclear Physics, Polish Academy of Sciences, Cracow, Poland" ] ]
Chiral quark models offer a practical and simple tool to describe covariantly both low and high energy phenomenology in combination with QCD evolution. This can be done in full harmony with chiral symmetry and electromagnetic gauge invariance. We review the recently proposed spectral quark model where all these constraints are implemented.
1612.03914
Wouter Dekens
V. Cirigliano, W. Dekens, J. de Vries, and E. Mereghetti
An $\epsilon'$ improvement from right-handed currents
17 pages
null
10.1016/j.physletb.2017.01.037
LA-UR-16-28961, NIKHEF 2016-056
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent lattice QCD calculations of direct CP violation in $K_L \to \pi \pi$ decays indicate tension with the experimental results. Assuming this tension to be real, we investigate a possible beyond-the-Standard Model explanation via right-handed charged currents. By using chiral perturbation theory in combination with lattice QCD results, we accurately calculate the modification of $\epsilon'/\epsilon$ induced by right-handed charged currents and extract values of the couplings that are necessary to explain the discrepancy, pointing to a scale around $10^2$ TeV. We find that couplings of this size are not in conflict with constraints from other precision experiments, but next-generation hadronic electric dipole moment searches (such as neutron and ${}^{225}$Ra) can falsify this scenario. We work out in detail a direct link, based on chiral perturbation theory, between CP violation in the kaon sector and electric dipole moments induced by right-handed currents which can be used in future analyses of left-right symmetric models.
[ { "created": "Mon, 12 Dec 2016 21:00:03 GMT", "version": "v1" } ]
2017-01-25
[ [ "Cirigliano", "V.", "" ], [ "Dekens", "W.", "" ], [ "de Vries", "J.", "" ], [ "Mereghetti", "E.", "" ] ]
Recent lattice QCD calculations of direct CP violation in $K_L \to \pi \pi$ decays indicate tension with the experimental results. Assuming this tension to be real, we investigate a possible beyond-the-Standard Model explanation via right-handed charged currents. By using chiral perturbation theory in combination with lattice QCD results, we accurately calculate the modification of $\epsilon'/\epsilon$ induced by right-handed charged currents and extract values of the couplings that are necessary to explain the discrepancy, pointing to a scale around $10^2$ TeV. We find that couplings of this size are not in conflict with constraints from other precision experiments, but next-generation hadronic electric dipole moment searches (such as neutron and ${}^{225}$Ra) can falsify this scenario. We work out in detail a direct link, based on chiral perturbation theory, between CP violation in the kaon sector and electric dipole moments induced by right-handed currents which can be used in future analyses of left-right symmetric models.
hep-ph/0409362
Dmitri Diakonov
Dmitri Diakonov and Victor Petrov
Baryons as Fock states of 3,5,... quarks
20 p., 6 figs
Annalen Phys.13:637-650,2004
10.1002/andp.200410106
JLAB-THY-04-275
hep-ph
null
We present a generating functional producing quark wave functions of all Fock states in the octet, decuplet and antidecuplet baryons in the mean field approximation, both in the rest and infinite momentum frames. In particular, for the usual octet and decuplet baryons we get the SU(6)-symmetric wave functions for their 3-quark component but with specific corrections from relativism and from additional quark-antiquark pairs. For the exotic antidecuplet baryons we obtain the 5-quark wave function.
[ { "created": "Thu, 30 Sep 2004 19:53:42 GMT", "version": "v1" } ]
2014-11-18
[ [ "Diakonov", "Dmitri", "" ], [ "Petrov", "Victor", "" ] ]
We present a generating functional producing quark wave functions of all Fock states in the octet, decuplet and antidecuplet baryons in the mean field approximation, both in the rest and infinite momentum frames. In particular, for the usual octet and decuplet baryons we get the SU(6)-symmetric wave functions for their 3-quark component but with specific corrections from relativism and from additional quark-antiquark pairs. For the exotic antidecuplet baryons we obtain the 5-quark wave function.
hep-ph/9508235
Denis Perret-Gallix
Denis Perrer-Gallix (LAPP, IN2P3-CNRS)
Towards a Complete Feynman Diagrams Automatic Computation System
12 pages, Invited talk at the AIHENP-95 workshop
Int.J.Mod.Phys.C6:531-540,1995
10.1142/S0129183195000393
LAPP-EXP-95.06
hep-ph
null
Complete Feynman diagram automatic computation systems are now coming of age after many years of development. They are made available to the high energy physics community through user-friendly interfaces. Theorists and experimentalists can benefit from these powerful packages for speeding up time consuming calculations and for preparing event generators. The general architecture of these packages is presented and the current development of the one-loop diagrams extension is discussed. A rapid description of the prominent packages and tools is then proposed. Finally, the necessity for defining a standardization scheme is heavily stressed for the benefit of developers and users.
[ { "created": "Fri, 4 Aug 1995 18:24:59 GMT", "version": "v1" } ]
2011-04-15
[ [ "Perrer-Gallix", "Denis", "", "LAPP, IN2P3-CNRS" ] ]
Complete Feynman diagram automatic computation systems are now coming of age after many years of development. They are made available to the high energy physics community through user-friendly interfaces. Theorists and experimentalists can benefit from these powerful packages for speeding up time consuming calculations and for preparing event generators. The general architecture of these packages is presented and the current development of the one-loop diagrams extension is discussed. A rapid description of the prominent packages and tools is then proposed. Finally, the necessity for defining a standardization scheme is heavily stressed for the benefit of developers and users.
2106.05298
Mathias Pierre
Enrique Fernandez-Martinez, Mathias Pierre, Emanuelle Pinsard and Salvador Rosauro-Alcaraz
Inverse Seesaw, dark matter and the Hubble tension
22 pages, 2 figures
null
10.1140/epjc/s10052-021-09760-y
IFT-UAM/CSIC-21-64
hep-ph astro-ph.CO hep-th
http://creativecommons.org/licenses/by/4.0/
We consider the inverse Seesaw scenario for neutrino masses with the approximate Lepton number symmetry broken dynamically by a scalar with Lepton number two. We show that the Majoron associated to the spontaneous symmetry breaking can alleviate the Hubble tension through its contribution to $\Delta N_\text{eff}$ and late decays to neutrinos. Among the additional fermionic states required for realizing the inverse Seesaw mechanism, sterile neutrinos at the keV-MeV scale can account for all the dark matter component of the Universe if produced via freeze-in from the decays of heavier degrees of freedom.
[ { "created": "Wed, 9 Jun 2021 18:00:06 GMT", "version": "v1" } ]
2021-11-17
[ [ "Fernandez-Martinez", "Enrique", "" ], [ "Pierre", "Mathias", "" ], [ "Pinsard", "Emanuelle", "" ], [ "Rosauro-Alcaraz", "Salvador", "" ] ]
We consider the inverse Seesaw scenario for neutrino masses with the approximate Lepton number symmetry broken dynamically by a scalar with Lepton number two. We show that the Majoron associated to the spontaneous symmetry breaking can alleviate the Hubble tension through its contribution to $\Delta N_\text{eff}$ and late decays to neutrinos. Among the additional fermionic states required for realizing the inverse Seesaw mechanism, sterile neutrinos at the keV-MeV scale can account for all the dark matter component of the Universe if produced via freeze-in from the decays of heavier degrees of freedom.
1202.4221
Premomoy Ghosh
Premomoy Ghosh
Negative binomial multiplicity distribution in proton-proton collisions in limited pseudorapidity intervals at LHC up to sqrt (s) = 7 TeV and the clan model
9 pages 8 figures. Accepted for publication in Physical Review D
null
10.1103/PhysRevD.85.054017
null
hep-ph hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Experiments at the Large Hadron Collider (LHC) have measured multiplicity distributions in proton-proton collisions at a new domain of center-of-mass energy ($\sqrt {s}$) in limited pseudorapidity intervals. We analyze multiplicity distribution data of proton-proton collisions at LHC energies as measured by the Compact Muon Solenoid (CMS) experiment in terms of characteristic parameters of the Negative Binomial Distribution (NBD) function that has played a significant role in describing multiplicity distribution data of particle production in high energy physics experiments, in the pre-LHC energy-range, in various kinds of collisions for a wide range of collision energy and for different kinematic ranges. Beside a single NBD, we apply the formalism of weighted superposition of two NBDs to examine if the multiplicity distribution data of CMS could be better explained. The weighted superposition of two NBDs indeed explain the distribution data better at the highest available LHC energy and in large interval of phase space. The two-NBD formalism further reveals that the energy invariance of the multiplicity distribution of the "soft" component of particle production in hadronic collisions is valid at LHC also, as it is at RHIC and Tevatron. We analyze the data further in terms of clan parameters in the framework of the two-NBD model.
[ { "created": "Mon, 20 Feb 2012 04:54:24 GMT", "version": "v1" } ]
2015-06-04
[ [ "Ghosh", "Premomoy", "" ] ]
Experiments at the Large Hadron Collider (LHC) have measured multiplicity distributions in proton-proton collisions at a new domain of center-of-mass energy ($\sqrt {s}$) in limited pseudorapidity intervals. We analyze multiplicity distribution data of proton-proton collisions at LHC energies as measured by the Compact Muon Solenoid (CMS) experiment in terms of characteristic parameters of the Negative Binomial Distribution (NBD) function that has played a significant role in describing multiplicity distribution data of particle production in high energy physics experiments, in the pre-LHC energy-range, in various kinds of collisions for a wide range of collision energy and for different kinematic ranges. Beside a single NBD, we apply the formalism of weighted superposition of two NBDs to examine if the multiplicity distribution data of CMS could be better explained. The weighted superposition of two NBDs indeed explain the distribution data better at the highest available LHC energy and in large interval of phase space. The two-NBD formalism further reveals that the energy invariance of the multiplicity distribution of the "soft" component of particle production in hadronic collisions is valid at LHC also, as it is at RHIC and Tevatron. We analyze the data further in terms of clan parameters in the framework of the two-NBD model.
2102.05366
Jan Sch\"utte-Engel
Jan Sch\"utte-Engel, David J. E. Marsh, Alexander J. Millar, Akihiko Sekine, Francesca Chadha-Day, Sebastian Hoof, Mazhar Ali, Kin-Chung Fong, Edward Hardy, and Libor \v{S}mejkal
Axion Quasiparticles for Axion Dark Matter Detection
78 pages + appendices, v2: reference list extended, added one more case to fig 23
null
10.1088/1475-7516/2021/08/066
IPPP/20/78, NORDITA-2021-007
hep-ph cond-mat.mes-hall cond-mat.mtrl-sci cond-mat.str-el
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has been suggested that certain antiferromagnetic topological insulators contain axion quasiparticles (AQs), and that such materials could be used to detect axion dark matter (DM). The AQ is a longitudinal antiferromagnetic spin fluctuation coupled to the electromagnetic Chern-Simons term, which, in the presence of an applied magnetic field, leads to mass mixing between the AQ and the electric field. The electromagnetic boundary conditions and transmission and reflection coefficients are computed. A model for including losses into this system is presented, and the resulting linewidth is computed. It is shown how transmission spectroscopy can be used to measure the resonant frequencies and damping coefficients of the material, and demonstrate conclusively the existence of the AQ. The dispersion relation and boundary conditions permit resonant conversion of axion DM into THz photons in a material volume that is independent of the resonant frequency, which is tuneable via an applied magnetic field. A parameter study for axion DM detection is performed, computing boost amplitudes and bandwidths using realistic material properties including loss. The proposal could allow for detection of axion DM in the mass range between 1 and 10 meV using current and near future technology.
[ { "created": "Wed, 10 Feb 2021 10:11:47 GMT", "version": "v1" }, { "created": "Mon, 6 Sep 2021 19:23:46 GMT", "version": "v2" } ]
2021-09-08
[ [ "Schütte-Engel", "Jan", "" ], [ "Marsh", "David J. E.", "" ], [ "Millar", "Alexander J.", "" ], [ "Sekine", "Akihiko", "" ], [ "Chadha-Day", "Francesca", "" ], [ "Hoof", "Sebastian", "" ], [ "Ali", "Mazhar", "" ], [ "Fong", "Kin-Chung", "" ], [ "Hardy", "Edward", "" ], [ "Šmejkal", "Libor", "" ] ]
It has been suggested that certain antiferromagnetic topological insulators contain axion quasiparticles (AQs), and that such materials could be used to detect axion dark matter (DM). The AQ is a longitudinal antiferromagnetic spin fluctuation coupled to the electromagnetic Chern-Simons term, which, in the presence of an applied magnetic field, leads to mass mixing between the AQ and the electric field. The electromagnetic boundary conditions and transmission and reflection coefficients are computed. A model for including losses into this system is presented, and the resulting linewidth is computed. It is shown how transmission spectroscopy can be used to measure the resonant frequencies and damping coefficients of the material, and demonstrate conclusively the existence of the AQ. The dispersion relation and boundary conditions permit resonant conversion of axion DM into THz photons in a material volume that is independent of the resonant frequency, which is tuneable via an applied magnetic field. A parameter study for axion DM detection is performed, computing boost amplitudes and bandwidths using realistic material properties including loss. The proposal could allow for detection of axion DM in the mass range between 1 and 10 meV using current and near future technology.
hep-ph/9807252
Jacek Wosiek
A. Bialas, W. Czyz and J. Wosiek (Jagellonian University)
Studying thermodynamics in heavy ion collisions
12 pages, LaTeX with two eps figures
Acta Phys.Polon. B30 (1999) 107-117
null
TPJU-15/98
hep-ph
null
We discuss the possibility to measure entropy of the system created in heavy ion collisions using the Ma coincidence method.
[ { "created": "Mon, 6 Jul 1998 08:31:17 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bialas", "A.", "", "Jagellonian University" ], [ "Czyz", "W.", "", "Jagellonian University" ], [ "Wosiek", "J.", "", "Jagellonian University" ] ]
We discuss the possibility to measure entropy of the system created in heavy ion collisions using the Ma coincidence method.
hep-ph/0109238
Jonathan L. Rosner
Michael Gronau and Jonathan L. Rosner
Implications of CP Asymmetry Limits for $B \to K \pi$ and $B \to \pi \pi$
16 pages, LaTeX, 3 figures, revised version to be published in Phys. Rev. D. References added and updated
Phys.Rev.D65:013004,2002; Erratum-ibid.D65:079901,2002
10.1103/PhysRevD.65.013004 10.1103/PhysRevD.65.079901
TECHNION-PH-2001-35, EFI 01-42
hep-ph
null
Recent experimental limits for the direct CP asymmetries in $B^0 \to K^+ \pi^-$, $B^+ \to K^+ \pi^0$, $B^+ \to K^0 \pi^+$, and $B^0 \to \pi^+ \pi^-$, and for the indirect CP asymmetry in $B^0 \to \pi^+ \pi^-$, are combined with information on CP-averaged branching ratios to shed light on weak and strong phases. At present such bounds favor $\gamma \ge 60^\circ$ at the $1 \sigma$ level. The prospects for further improvements are discussed.
[ { "created": "Tue, 25 Sep 2001 17:18:21 GMT", "version": "v1" }, { "created": "Mon, 15 Oct 2001 20:15:00 GMT", "version": "v2" } ]
2014-11-17
[ [ "Gronau", "Michael", "" ], [ "Rosner", "Jonathan L.", "" ] ]
Recent experimental limits for the direct CP asymmetries in $B^0 \to K^+ \pi^-$, $B^+ \to K^+ \pi^0$, $B^+ \to K^0 \pi^+$, and $B^0 \to \pi^+ \pi^-$, and for the indirect CP asymmetry in $B^0 \to \pi^+ \pi^-$, are combined with information on CP-averaged branching ratios to shed light on weak and strong phases. At present such bounds favor $\gamma \ge 60^\circ$ at the $1 \sigma$ level. The prospects for further improvements are discussed.
1402.7188
Takeshi Araki
Takeshi Araki, Eiichi Takasugi
Effects on sin\theta_{12} from perturbation of the neutrino mixing matrix with the partially degenerated neutrino masses
v1: 14 pages, 6 figures; v2: minor changes, references added, 16 pages, 6 figures
null
10.1093/ptep/ptu053
MISC-2014-02
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a situation where the leading-order neutrino mass matrix is derived by a theoretical ansatz and reproduces the experimental data well, but not completely. Then, the next stage is to try to fully reproduce the data by adding small perturbation terms. In this paper, we obtain the analytical method to diagonalize the perturbed mass matrix and find a consistency condition that parameters should satisfy not to change \sin\theta_{12} much. This condition could cause parameter tuning and plays a crucial role in relating the added perturbation terms with the prediction analytically, in particular, for the case of the partially quasi-degenerated neutrino masses (m_2 \simeq m_1) where neutrinoless double beta decays would be observed in the phase-II experiments.
[ { "created": "Fri, 28 Feb 2014 10:34:58 GMT", "version": "v1" }, { "created": "Fri, 9 May 2014 08:19:22 GMT", "version": "v2" } ]
2016-06-21
[ [ "Araki", "Takeshi", "" ], [ "Takasugi", "Eiichi", "" ] ]
We consider a situation where the leading-order neutrino mass matrix is derived by a theoretical ansatz and reproduces the experimental data well, but not completely. Then, the next stage is to try to fully reproduce the data by adding small perturbation terms. In this paper, we obtain the analytical method to diagonalize the perturbed mass matrix and find a consistency condition that parameters should satisfy not to change \sin\theta_{12} much. This condition could cause parameter tuning and plays a crucial role in relating the added perturbation terms with the prediction analytically, in particular, for the case of the partially quasi-degenerated neutrino masses (m_2 \simeq m_1) where neutrinoless double beta decays would be observed in the phase-II experiments.
1403.4284
Andrzej Czarnecki
Yi Liang, Paul L. McGrath and Andrzej Czarnecki
Anomalous magnetic moment of the positronium ion
7 pages
null
10.1088/1367-2630/16/6/063045
Alberta Thy 6-14
hep-ph physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We determine the gyromagnetic factor of the positronium ion, a three-body system consisting of two electrons and a positron, including first relativistic corrections. We find that the g-factor is modified by a term -0.51(1)alpha^2, exceeding 15 times the alpha^2 correction for a free electron. We compare this effect with analogous results found previously in atomic positronium and in hydrogen-like ions.
[ { "created": "Mon, 17 Mar 2014 22:04:29 GMT", "version": "v1" } ]
2015-06-19
[ [ "Liang", "Yi", "" ], [ "McGrath", "Paul L.", "" ], [ "Czarnecki", "Andrzej", "" ] ]
We determine the gyromagnetic factor of the positronium ion, a three-body system consisting of two electrons and a positron, including first relativistic corrections. We find that the g-factor is modified by a term -0.51(1)alpha^2, exceeding 15 times the alpha^2 correction for a free electron. We compare this effect with analogous results found previously in atomic positronium and in hydrogen-like ions.
2211.06347
John Hardin
J.M.Hardin
Wilks's Theorem, Global Fits, and Neutrino Oscillations
Updates addressing reviewer comments
2024 Eur. J. Phys. 45 025806
10.1088/1361-6404/ad261d
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Tests of models for new physics appearing in neutrino experiments often involve global fits to a quantum mechanical effect called neutrino oscillations. This paper introduces students to methods commonly used in these global fits starting from an understanding of more conventional fitting methods using log-likelihood and $\chi^2$ minimization. Specifically, we discuss how the $\Delta\chi^2$, which compares the $\chi^2$ of the fit with the new physics to the $\chi^2$ of the Standard Model prediction, is often interpreted using Wilks's theorem. This paper uses toy models to explore the properties of $\Delta\chi^2$ as a test statistic for oscillating functions. The statistics of such models are shown to deviate from Wilks's theorem. Tests for new physics also often examine data subsets for "tension" called the "parameter goodness of fit". In this paper, we explain this approach and use toy models to examine the validity of the probabilities from this test also. Although we have chosen a specific scenario -- neutrino oscillations -- to illustrate important points, students should keep in mind that these points are widely applicable when fitting multiple data sets to complex functions.
[ { "created": "Fri, 11 Nov 2022 16:48:15 GMT", "version": "v1" }, { "created": "Thu, 8 Aug 2024 15:05:00 GMT", "version": "v2" } ]
2024-08-09
[ [ "Hardin", "J. M.", "" ] ]
Tests of models for new physics appearing in neutrino experiments often involve global fits to a quantum mechanical effect called neutrino oscillations. This paper introduces students to methods commonly used in these global fits starting from an understanding of more conventional fitting methods using log-likelihood and $\chi^2$ minimization. Specifically, we discuss how the $\Delta\chi^2$, which compares the $\chi^2$ of the fit with the new physics to the $\chi^2$ of the Standard Model prediction, is often interpreted using Wilks's theorem. This paper uses toy models to explore the properties of $\Delta\chi^2$ as a test statistic for oscillating functions. The statistics of such models are shown to deviate from Wilks's theorem. Tests for new physics also often examine data subsets for "tension" called the "parameter goodness of fit". In this paper, we explain this approach and use toy models to examine the validity of the probabilities from this test also. Although we have chosen a specific scenario -- neutrino oscillations -- to illustrate important points, students should keep in mind that these points are widely applicable when fitting multiple data sets to complex functions.
1005.1938
Shamayita Ray Dr.
Shamayita Ray (Cornell U., LEPP)
Renormalization group evolution of neutrino masses and mixing in seesaw models: A review
54 pages. Invited review submitted to IJMPA
Int.J.Mod.Phys.A25:4339-4384,2010
10.1142/S0217751X10049839
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider different extensions of the standard model which can give rise to the small active neutrino masses through seesaw mechanisms, and their mixing. These tiny neutrino masses are generated at some high energy scale by the heavy seesaw fields which then get sequentially decoupled to give an effective dimension-5 operator. The renormalization group evolution of the masses and the mixing parameters of the three active neutrinos in the high energy as well as the low energy effective theory is reviewed in this article.
[ { "created": "Tue, 11 May 2010 20:27:52 GMT", "version": "v1" } ]
2015-03-17
[ [ "Ray", "Shamayita", "", "Cornell U., LEPP" ] ]
We consider different extensions of the standard model which can give rise to the small active neutrino masses through seesaw mechanisms, and their mixing. These tiny neutrino masses are generated at some high energy scale by the heavy seesaw fields which then get sequentially decoupled to give an effective dimension-5 operator. The renormalization group evolution of the masses and the mixing parameters of the three active neutrinos in the high energy as well as the low energy effective theory is reviewed in this article.
1512.03364
Francesco Giovanni Celiberto
F. Caporale, Francesco Giovanni Celiberto, G. Chachamis, A. Sabio Vera
Multi-Regge kinematics and azimuthal angle observables for inclusive four-jet production
13 pages, 4 figures
null
10.1140/epjc/s10052-016-3963-6
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We evaluate differential cross sections for production of four jets in multi-Regge kinematics at a hadron collider. The main focus lies on azimuthal angle dependences. As in previous studies, the ratios of correlation functions of products of cosines of azimuthal angle differences among the tagged jets offer us the cleanest quantities to compare with experimental data. The calculations are based on the jet production from a single BFKL ladder with a convolution of three BFKL Green functions where we always have two forward/backward jets tagged in the final state. We also demand the tagging of two further jets in more central regions of the detectors with a relative separation in rapidity from each other, plus the inclusive production of an arbitrary number of mini-jets. We show that dependences on the transverse momenta and rapidity of the two central jets can be a distinct signal of the onset of BFKL dynamics.
[ { "created": "Thu, 10 Dec 2015 18:40:00 GMT", "version": "v1" }, { "created": "Wed, 25 Jan 2017 18:25:16 GMT", "version": "v2" } ]
2017-01-26
[ [ "Caporale", "F.", "" ], [ "Celiberto", "Francesco Giovanni", "" ], [ "Chachamis", "G.", "" ], [ "Vera", "A. Sabio", "" ] ]
We evaluate differential cross sections for production of four jets in multi-Regge kinematics at a hadron collider. The main focus lies on azimuthal angle dependences. As in previous studies, the ratios of correlation functions of products of cosines of azimuthal angle differences among the tagged jets offer us the cleanest quantities to compare with experimental data. The calculations are based on the jet production from a single BFKL ladder with a convolution of three BFKL Green functions where we always have two forward/backward jets tagged in the final state. We also demand the tagging of two further jets in more central regions of the detectors with a relative separation in rapidity from each other, plus the inclusive production of an arbitrary number of mini-jets. We show that dependences on the transverse momenta and rapidity of the two central jets can be a distinct signal of the onset of BFKL dynamics.
hep-ph/9701232
Tomohiro Matsuda
Tomohiro Matsuda
A natural solution to the $\mu$-problem in dynamical supergravity model
6 pages, Latex, accepted for publication in Phys.Rev.D
Phys.Rev. D58 (1998) 035004
10.1103/PhysRevD.58.035004
UT-766
hep-ph
null
The Higgs mixing term coefficient $\mu$ is calculated in the supersymmetric theory which possesses a non-anomalous $U(1)_{R}$ symmetry in the limit of global supersymmetry. In this model, supersymmetry is assumed to be broken by gaugino condensation in the hidden sector when the supergravity effects are turned on. The soft breaking terms in the visible sector and the $\mu$ term of order the weak scale are produced in a simple manner.
[ { "created": "Tue, 7 Jan 1997 03:48:26 GMT", "version": "v1" }, { "created": "Thu, 10 Jul 1997 02:37:03 GMT", "version": "v2" }, { "created": "Tue, 21 Oct 1997 02:56:00 GMT", "version": "v3" }, { "created": "Wed, 29 Apr 1998 05:32:59 GMT", "version": "v4" } ]
2009-10-30
[ [ "Matsuda", "Tomohiro", "" ] ]
The Higgs mixing term coefficient $\mu$ is calculated in the supersymmetric theory which possesses a non-anomalous $U(1)_{R}$ symmetry in the limit of global supersymmetry. In this model, supersymmetry is assumed to be broken by gaugino condensation in the hidden sector when the supergravity effects are turned on. The soft breaking terms in the visible sector and the $\mu$ term of order the weak scale are produced in a simple manner.
1008.3638
Dmitri Antonov
D. Antonov, J.E.F.T. Ribeiro, A.V. Nefediev
QCD relics from the early Universe
30 pages, 4 figures
null
null
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We suggest the possibility of creation in the early Universe of stable domains of radius a few kilometers wide, formed by coherently excited states of $\pi$-mesons. Such domains appear dark to an external observer, since the decay rate of the said coherent pionic states into photons is vanishingly small. The related thermal insulation of the domains from the outer world could have allowed them to survive till present days. The estimated maximum radius and the period of rotation of such objects turn out to be compatible with those of certain pulsars.
[ { "created": "Sat, 21 Aug 2010 15:18:00 GMT", "version": "v1" } ]
2010-08-24
[ [ "Antonov", "D.", "" ], [ "Ribeiro", "J. E. F. T.", "" ], [ "Nefediev", "A. V.", "" ] ]
We suggest the possibility of creation in the early Universe of stable domains of radius a few kilometers wide, formed by coherently excited states of $\pi$-mesons. Such domains appear dark to an external observer, since the decay rate of the said coherent pionic states into photons is vanishingly small. The related thermal insulation of the domains from the outer world could have allowed them to survive till present days. The estimated maximum radius and the period of rotation of such objects turn out to be compatible with those of certain pulsars.
hep-ph/0011161
null
Tao Huang, Zuo-Hong Li, Xiang-Yao Wu
Improved approach to the heavy-to-light form factors in the light-cone QCD sum
New version to appear in PRD
null
10.1103/PhysRevD.63.094001
null
hep-ph
null
A systematic analysis shows that the main uncertainties in the form factors are due to the twist-3 wave functions of the light mesons in the light-cone QCD sum rules. We propose an improved approach, in which the twist-3 wave functions doesn't make any contribution and therefore the possible pollution by them can be avoided, to re-examine $B \to \pi$ semileptonic form factors. Also, a comparison between the previous and our results from the light-cone QCD sum rules is made. Our method will be beneficial to the precise extracting of $\mid{V_{ub}}\mid$ from the experimental data on the processes $B \to \pi \ell \widetilde{\nu_\ell}$.
[ { "created": "Mon, 13 Nov 2000 03:37:02 GMT", "version": "v1" }, { "created": "Tue, 20 Mar 2001 13:40:19 GMT", "version": "v2" } ]
2009-10-31
[ [ "Huang", "Tao", "" ], [ "Li", "Zuo-Hong", "" ], [ "Wu", "Xiang-Yao", "" ] ]
A systematic analysis shows that the main uncertainties in the form factors are due to the twist-3 wave functions of the light mesons in the light-cone QCD sum rules. We propose an improved approach, in which the twist-3 wave functions doesn't make any contribution and therefore the possible pollution by them can be avoided, to re-examine $B \to \pi$ semileptonic form factors. Also, a comparison between the previous and our results from the light-cone QCD sum rules is made. Our method will be beneficial to the precise extracting of $\mid{V_{ub}}\mid$ from the experimental data on the processes $B \to \pi \ell \widetilde{\nu_\ell}$.
1703.04759
Nikita Blinov
Nikita Blinov and Anson Hook
Particle Asymmetries from Quantum Statistics
Minor changes to match journal version
Phys. Rev. D 95, 095014 (2017)
10.1103/PhysRevD.95.095014
SLAC-PUB-16936
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a class of baryogenesis models where the Lagrangian in the visible sector is Charge-Parity (CP) invariant and a baryon asymmetry is produced only when quantum statistics is taken into account. The CP symmetry is broken by matter effects, namely the assumption that the primordial plasma contains another asymmetric species, such as dark matter. Out-of-equilibrium baryon number violating decays can then generate an asymmetry through Bose enhancement and/or Pauli blocking of certain decay channels.
[ { "created": "Tue, 14 Mar 2017 22:14:32 GMT", "version": "v1" }, { "created": "Mon, 22 May 2017 17:13:29 GMT", "version": "v2" } ]
2017-05-24
[ [ "Blinov", "Nikita", "" ], [ "Hook", "Anson", "" ] ]
We consider a class of baryogenesis models where the Lagrangian in the visible sector is Charge-Parity (CP) invariant and a baryon asymmetry is produced only when quantum statistics is taken into account. The CP symmetry is broken by matter effects, namely the assumption that the primordial plasma contains another asymmetric species, such as dark matter. Out-of-equilibrium baryon number violating decays can then generate an asymmetry through Bose enhancement and/or Pauli blocking of certain decay channels.
hep-ph/0201024
Gilberto Tavares Velasco
F. Larios, M.A. Perez, G. Tavares-Velasco
Constraints on neutrino-photon interactions from rare Z decays
11 pages, 5 figures, elsart format
Phys.Lett. B531 (2002) 231-236
10.1016/S0370-2693(02)01494-6
null
hep-ph
null
It is shown that the rare decays $Z \to \nu \bar{nu} \gamma$ and $Z \to \nu \bar{\nu} \gamma \gamma$ are useful to put model-independent bounds on neutrino-one-photon and neutrino-two-photon interactions. The results are then used to constrain the $\tau$ neutrino magnetic moment and the double radiative decay $\nu_j \to \nu_i \gamma \gamma$. It is found that the decay $Z \to \nu \bar{nu} \gamma$ gives a more stringent bound on the $\tau$ neutrino magnetic moment than that obtained from $Z \to \nu \bar{\nu} \gamma \gamma$; the latter decay in turn gives limits on the neutrino-two-photon interaction that are less stringent than those obtained for a sterile neutrino $\nu_s$ from the analysis of $\nu_\mu N \to \nu_s N$ conversion.
[ { "created": "Fri, 4 Jan 2002 21:54:31 GMT", "version": "v1" } ]
2009-11-07
[ [ "Larios", "F.", "" ], [ "Perez", "M. A.", "" ], [ "Tavares-Velasco", "G.", "" ] ]
It is shown that the rare decays $Z \to \nu \bar{nu} \gamma$ and $Z \to \nu \bar{\nu} \gamma \gamma$ are useful to put model-independent bounds on neutrino-one-photon and neutrino-two-photon interactions. The results are then used to constrain the $\tau$ neutrino magnetic moment and the double radiative decay $\nu_j \to \nu_i \gamma \gamma$. It is found that the decay $Z \to \nu \bar{nu} \gamma$ gives a more stringent bound on the $\tau$ neutrino magnetic moment than that obtained from $Z \to \nu \bar{\nu} \gamma \gamma$; the latter decay in turn gives limits on the neutrino-two-photon interaction that are less stringent than those obtained for a sterile neutrino $\nu_s$ from the analysis of $\nu_\mu N \to \nu_s N$ conversion.
hep-ph/0506134
Olena Linnyk
O. Linnyk, K. Gallmeister, S. Leupold, U. Mosel
Prediction for the transverse momentum distribution of Drell-Yan dileptons at GSI-PANDA
4 pages, 7 figures, RevTex; the published version: typos corrected, minor changes to the text
Phys.Rev.D73:037502,2006
10.1103/PhysRevD.73.037502
null
hep-ph nucl-th
null
We predict the triple differential cross section of the Drell-Yan process (pbar p -> l^+l^-X) in the kinematical regimes relevant for the upcoming PANDA experiment, using a model that accounts for quark virtuality as well as primordial transverse momentum. We find a cross section magnitude of up to 10 nb in the low mass region. A measurement with 10% accuracy is desirable in order to constrain the partonic transverse momentum dispersion and the spectral function width within +-50 MeV and to study their evolution with M and sqrt(s).
[ { "created": "Tue, 14 Jun 2005 12:25:47 GMT", "version": "v1" }, { "created": "Mon, 24 Oct 2005 13:36:51 GMT", "version": "v2" }, { "created": "Fri, 17 Mar 2006 17:56:02 GMT", "version": "v3" } ]
2008-11-26
[ [ "Linnyk", "O.", "" ], [ "Gallmeister", "K.", "" ], [ "Leupold", "S.", "" ], [ "Mosel", "U.", "" ] ]
We predict the triple differential cross section of the Drell-Yan process (pbar p -> l^+l^-X) in the kinematical regimes relevant for the upcoming PANDA experiment, using a model that accounts for quark virtuality as well as primordial transverse momentum. We find a cross section magnitude of up to 10 nb in the low mass region. A measurement with 10% accuracy is desirable in order to constrain the partonic transverse momentum dispersion and the spectral function width within +-50 MeV and to study their evolution with M and sqrt(s).
1108.5178
Jing Shao
Gordon Kane, Jing Shao, Scott Watson and Hai-Bo Yu
The Baryon-Dark Matter Ratio Via Moduli Decay After Affleck-Dine Baryogenesis
12 pages, no figure. v2: references added
null
10.1088/1475-7516/2011/11/012
MCTP-11-33
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Low-scale supersymmetry breaking in string motivated theories implies the presence of O(100) TeV scale moduli, which generically lead to a significant modification of the history of the universe prior to Big Bang Nucleosynthesis. Such an approach implies a non-thermal origin for dark matter resulting from scalar decay, where the lightest supersymmetric particle can account for the observed dark matter relic density. We study the further effect of the decay on the baryon asymmetry of the universe, and find that this can satisfactorily address the problem of the over-production of the baryon asymmetry by the Affleck-Dine mechanism in the MSSM. Remarkably, there is a natural connection between the baryon and dark matter abundances today, which leads to a solution of the `Cosmic Coincidence Problem'.
[ { "created": "Thu, 25 Aug 2011 20:00:16 GMT", "version": "v1" }, { "created": "Wed, 7 Sep 2011 18:37:54 GMT", "version": "v2" } ]
2015-05-30
[ [ "Kane", "Gordon", "" ], [ "Shao", "Jing", "" ], [ "Watson", "Scott", "" ], [ "Yu", "Hai-Bo", "" ] ]
Low-scale supersymmetry breaking in string motivated theories implies the presence of O(100) TeV scale moduli, which generically lead to a significant modification of the history of the universe prior to Big Bang Nucleosynthesis. Such an approach implies a non-thermal origin for dark matter resulting from scalar decay, where the lightest supersymmetric particle can account for the observed dark matter relic density. We study the further effect of the decay on the baryon asymmetry of the universe, and find that this can satisfactorily address the problem of the over-production of the baryon asymmetry by the Affleck-Dine mechanism in the MSSM. Remarkably, there is a natural connection between the baryon and dark matter abundances today, which leads to a solution of the `Cosmic Coincidence Problem'.
hep-ph/9503246
Joannis Papavassiliou
JOANNIS PAPAVASSILIOU and KOSTAS PHILIPPIDES
GAUGE INVARIANCE AND ANOMALOUS GAUGE BOSON COUPLINGS
Latex with all special macros included, 5 pages, no figures To appear in the Conference Proceedings for BEYOND THE STANDARD MODEL IV, Granlibakken, Lake Tahoe, Dec 13-18, 1994, hosted by Davis Institute for High Energy Physics. Talk presented By J. Papavassiliou.
null
null
null
hep-ph
null
Using the S--matrix pinch technique we obtain to one loop order, gauge independent $\gamma W^-W^+$ and $Z W^-W^+$ vertices in the context of the standard model, with all incoming momenta off--shell. We show that the vertices so constructed satisfy simple QED--like Ward identities. These gauge invariant vertices give rise to expressions for the magnetic dipole and electric quadrupole form factors of the W gauge boson, which, unlike previous treatments, satisfy the crucial properties of infrared finiteness and perturbative unitarity.
[ { "created": "Mon, 6 Mar 1995 21:46:10 GMT", "version": "v1" } ]
2016-09-01
[ [ "PAPAVASSILIOU", "JOANNIS", "" ], [ "PHILIPPIDES", "KOSTAS", "" ] ]
Using the S--matrix pinch technique we obtain to one loop order, gauge independent $\gamma W^-W^+$ and $Z W^-W^+$ vertices in the context of the standard model, with all incoming momenta off--shell. We show that the vertices so constructed satisfy simple QED--like Ward identities. These gauge invariant vertices give rise to expressions for the magnetic dipole and electric quadrupole form factors of the W gauge boson, which, unlike previous treatments, satisfy the crucial properties of infrared finiteness and perturbative unitarity.
2107.00859
Danny Marfatia
Danny Marfatia, Po-Yan Tseng
Correlated gravitational wave and microlensing signals of macroscopic dark matter
16 pages, 7 figures, 1 table. Version to appear in JHEP
JHEP 2111:068 (2021)
10.1007/JHEP11(2021)068
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Fermion dark matter particles can aggregate to form extended dark matter structures via a first-order phase transition in which the particles get trapped in the false vacuum. We study Fermi balls created in a phase transition induced by a generic quartic thermal effective potential. We show that for Fermi balls of mass, $3\times 10^{-12}M_\odot \lesssim M_{\rm FB} \lesssim 10^{-5}M_\odot$, correlated observations of gravitational waves produced during the phase transition (at SKA/THEIA/$\mu$Ares), and gravitational microlensing caused by Fermi balls (at Subaru-HSC), can be made.
[ { "created": "Fri, 2 Jul 2021 06:28:42 GMT", "version": "v1" }, { "created": "Thu, 28 Oct 2021 16:19:25 GMT", "version": "v2" } ]
2021-11-11
[ [ "Marfatia", "Danny", "" ], [ "Tseng", "Po-Yan", "" ] ]
Fermion dark matter particles can aggregate to form extended dark matter structures via a first-order phase transition in which the particles get trapped in the false vacuum. We study Fermi balls created in a phase transition induced by a generic quartic thermal effective potential. We show that for Fermi balls of mass, $3\times 10^{-12}M_\odot \lesssim M_{\rm FB} \lesssim 10^{-5}M_\odot$, correlated observations of gravitational waves produced during the phase transition (at SKA/THEIA/$\mu$Ares), and gravitational microlensing caused by Fermi balls (at Subaru-HSC), can be made.
1402.4079
Emilia Lewandowska
Krzysztof Golec-Biernat, Emilia Lewandowska
How to impose initial conditions for QCD evolution of double parton distributions?
7 pages, version accepted for publication in Phys. Rev. D
Phys. Rev. D 90, 014032 (2014)
10.1103/PhysRevD.90.014032
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Double parton distribution functions (DPDFs) are used in the QCD description of double parton scattering. The DPDFs evolve with hard scales through QCD evolution equations which obey nontrivial momentum and valence quark number sum rules. We describe an attempt to construct initial conditions for the evolution equations which exactly fulfil these sum rules and discuss its shortcomings. We also discuss the factorization of the DPDFs into a product of two single parton distribution functions at small values of the parton momentum fractions.
[ { "created": "Mon, 17 Feb 2014 17:41:44 GMT", "version": "v1" }, { "created": "Mon, 7 Apr 2014 15:05:27 GMT", "version": "v2" }, { "created": "Wed, 16 Jul 2014 11:41:42 GMT", "version": "v3" } ]
2014-07-30
[ [ "Golec-Biernat", "Krzysztof", "" ], [ "Lewandowska", "Emilia", "" ] ]
Double parton distribution functions (DPDFs) are used in the QCD description of double parton scattering. The DPDFs evolve with hard scales through QCD evolution equations which obey nontrivial momentum and valence quark number sum rules. We describe an attempt to construct initial conditions for the evolution equations which exactly fulfil these sum rules and discuss its shortcomings. We also discuss the factorization of the DPDFs into a product of two single parton distribution functions at small values of the parton momentum fractions.
1706.06138
Qin Chang
Qin Chang, Xiao-Nan Li, Xin-Qiang Li and Jun-Feng Sun
Study of the weak annihilation contributions in charmless $B_s\to VV$ decays
31 pages, 4 figures, 6 tables
null
10.1140/epjc/s10052-017-4980-9
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, in order to probe the spectator-scattering and weak annihilation contributions in charmless $B_s\to VV$ (where $V$ stands for a light vector meson) decays, we perform the $\chi^2$-analyses for the end-point parameters within the QCD factorization framework, under the constraints from the measured $\bar B_{s}\to$$\rho^0\phi$, $\phi K^{*0}$, $\phi \phi$ and $K^{*0}\bar K^{*0}$ decays. The fitted results indicate that the end-point parameters in the factorizable and nonfactorizable annihilation topologies are non-universal, which is also favored by the charmless $B\to PP$ and $PV$ (where $P$ stands for a light pseudo-scalar meson) decays observed in the previous work. Moreover, the abnormal polarization fractions $f_{L,\bot}(\bar B_{s}\to K^{*0}\bar K^{*0})=(20.1\pm7.0)\%\,,(58.4\pm8.5)\%$ measured by the LHCb collaboration can be reconciled through the weak annihilation corrections. However, the branching ratio of $\bar B_{s}\to\phi K^{*0}$ decay exhibits a tension between the data and theoretical result, which dominates the contributions to $\chi_{\rm min}^2$ in the fits. Using the fitted end-point parameters, we update the theoretical results for the charmless $B_s\to VV$ decays, which will be further tested by the LHCb and Belle-II experiments in the near future.
[ { "created": "Mon, 19 Jun 2017 18:55:25 GMT", "version": "v1" } ]
2017-08-02
[ [ "Chang", "Qin", "" ], [ "Li", "Xiao-Nan", "" ], [ "Li", "Xin-Qiang", "" ], [ "Sun", "Jun-Feng", "" ] ]
In this paper, in order to probe the spectator-scattering and weak annihilation contributions in charmless $B_s\to VV$ (where $V$ stands for a light vector meson) decays, we perform the $\chi^2$-analyses for the end-point parameters within the QCD factorization framework, under the constraints from the measured $\bar B_{s}\to$$\rho^0\phi$, $\phi K^{*0}$, $\phi \phi$ and $K^{*0}\bar K^{*0}$ decays. The fitted results indicate that the end-point parameters in the factorizable and nonfactorizable annihilation topologies are non-universal, which is also favored by the charmless $B\to PP$ and $PV$ (where $P$ stands for a light pseudo-scalar meson) decays observed in the previous work. Moreover, the abnormal polarization fractions $f_{L,\bot}(\bar B_{s}\to K^{*0}\bar K^{*0})=(20.1\pm7.0)\%\,,(58.4\pm8.5)\%$ measured by the LHCb collaboration can be reconciled through the weak annihilation corrections. However, the branching ratio of $\bar B_{s}\to\phi K^{*0}$ decay exhibits a tension between the data and theoretical result, which dominates the contributions to $\chi_{\rm min}^2$ in the fits. Using the fitted end-point parameters, we update the theoretical results for the charmless $B_s\to VV$ decays, which will be further tested by the LHCb and Belle-II experiments in the near future.
hep-ph/9606470
Dirk Graudenz
Dirk Graudenz (CERN)
Charged-Meson Production and Scaling Violations of Fragmentation Functions in Deeply Inelastic Scattering at HERA
10 pages (Latex); figures are included via epsfig. A style file derived from ``elsart.sty'' is included, as well as the ``elsart12.sty'' file. The AMSTEX fonts are required
Phys.Lett. B406 (1997) 178-183
10.1016/S0370-2693(97)00667-9
CERN-TH/96-155
hep-ph
null
We compare recent experimental results for one-particle-inclusive processes in deeply inelastic scattering at HERA with theoretical predictions in next-to-leading-order QCD perturbation theory, and study the factorization scale dependence of cross sections and charged multiplicities. In the future, for the HERA machine running at design luminosity, scaling violations of fragmentation functions permit the measurement of the strong coupling constant. We estimate the size of the statistical error of $\alpha_s$ that can be achieved, and study the theoretical error due to the various parton density parametrizations and due to the factorization scale dependence.
[ { "created": "Fri, 28 Jun 1996 10:21:26 GMT", "version": "v1" } ]
2009-10-28
[ [ "Graudenz", "Dirk", "", "CERN" ] ]
We compare recent experimental results for one-particle-inclusive processes in deeply inelastic scattering at HERA with theoretical predictions in next-to-leading-order QCD perturbation theory, and study the factorization scale dependence of cross sections and charged multiplicities. In the future, for the HERA machine running at design luminosity, scaling violations of fragmentation functions permit the measurement of the strong coupling constant. We estimate the size of the statistical error of $\alpha_s$ that can be achieved, and study the theoretical error due to the various parton density parametrizations and due to the factorization scale dependence.
hep-ph/9405245
Ed Stoeffhaas
V.Barger, M.S.Berger, P.Ohmann and R.J.N.Phillips
Multilepton SUSY signals from R-parity violation at the Tevatron
12 pages. Uses Revtex style files (available through hep-ph). 5 postscript figures included (uufiled). RAL-94-047, MAD/PH/831
Phys.Rev.D50:4299-4305,1994
10.1103/PhysRevD.50.4299
null
hep-ph
null
The expected trilepton signals from $p \bar p \to \chi^\pm_1\chi^0_2 \to (\chi^0_1\ell^\pm\nu) (\chi^0_1\ell'^+\ell'^-) $ will be converted into hadronically quiet multilepton signals, if the two final $\chi^0_1$ have leptonic $R$-parity-violating (RPV) decays $\chi^0_1 \to \ell \ell' \nu$. We make illustrative calculations of the acceptance for these spectacular RPV signals, and point out that distinctive multilepton signals are possible even when the $R$-conserving trilepton signals are blocked by the ``spoiler mode" $\chi^0_2 \to h^0 \chi^0_1$. Other channels such as $p\bar p\to \chi_1^\pm \chi_2^0 \to (\chi_1^0\ell^\pm\nu) (\chi_1^0\nu\nu)$, $p\bar p\to \chi_1^\pm \chi_1^0 \to (\chi_1^0\ell\nu)\chi_1^0$ and $p\bar p\to\chi_1^+\chi_1^-\to(\chi_1^0\ell^+\nu)(\chi_1^0\ell'^-\nu)$ can also give quiet multileptons from RPV. We investigate these signals in the context of supersymmetric models with radiative electroweak symmetry breaking, using examples in the low-$\tan\beta$ $\lambda_t$ fixed-point region.
[ { "created": "Fri, 6 May 1994 20:44:43 GMT", "version": "v1" } ]
2009-09-25
[ [ "Barger", "V.", "" ], [ "Berger", "M. S.", "" ], [ "Ohmann", "P.", "" ], [ "Phillips", "R. J. N.", "" ] ]
The expected trilepton signals from $p \bar p \to \chi^\pm_1\chi^0_2 \to (\chi^0_1\ell^\pm\nu) (\chi^0_1\ell'^+\ell'^-) $ will be converted into hadronically quiet multilepton signals, if the two final $\chi^0_1$ have leptonic $R$-parity-violating (RPV) decays $\chi^0_1 \to \ell \ell' \nu$. We make illustrative calculations of the acceptance for these spectacular RPV signals, and point out that distinctive multilepton signals are possible even when the $R$-conserving trilepton signals are blocked by the ``spoiler mode" $\chi^0_2 \to h^0 \chi^0_1$. Other channels such as $p\bar p\to \chi_1^\pm \chi_2^0 \to (\chi_1^0\ell^\pm\nu) (\chi_1^0\nu\nu)$, $p\bar p\to \chi_1^\pm \chi_1^0 \to (\chi_1^0\ell\nu)\chi_1^0$ and $p\bar p\to\chi_1^+\chi_1^-\to(\chi_1^0\ell^+\nu)(\chi_1^0\ell'^-\nu)$ can also give quiet multileptons from RPV. We investigate these signals in the context of supersymmetric models with radiative electroweak symmetry breaking, using examples in the low-$\tan\beta$ $\lambda_t$ fixed-point region.
0812.1337
Matthias Steinhauser
K.G. Chetyrkin, B.A. Kniehl, M. Steinhauser
Strong-Coupling Constant at Three Loops in Momentum Subtraction Scheme
17 pages, 5 figures
Nucl.Phys.B814:231-245,2009
10.1016/j.nuclphysb.2009.01.026
DESY 08-184, SFB/CPP-08-92, TTP08-50
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we compute the three-loop corrections to the $\beta$ function in a momentum subtraction (MOM) scheme with a massive quark. The calculation is performed in the background field formalism applying asymptotic expansions for small and large momenta. Special emphasis is devoted to the relation between the coupling constant in the MOM and $\overline{\rm{MS}}$ schemes as well as their ability to describe the phenomenon of decoupling. It is demonstrated by an explicit comparison that the $\overline{\rm{MS}}$ scheme can be consistently used to relate the values of the MOM-scheme strong-coupling constant in the energy regions higher and lower than the massive-quark production threshold. This procedure obviates the necessity to know the full mass dependence of the MOM $\beta$ function and clearly demonstrates the equivalence of both schemes for the description of physics outside the threshold region.
[ { "created": "Sun, 7 Dec 2008 11:17:40 GMT", "version": "v1" } ]
2010-04-23
[ [ "Chetyrkin", "K. G.", "" ], [ "Kniehl", "B. A.", "" ], [ "Steinhauser", "M.", "" ] ]
In this paper we compute the three-loop corrections to the $\beta$ function in a momentum subtraction (MOM) scheme with a massive quark. The calculation is performed in the background field formalism applying asymptotic expansions for small and large momenta. Special emphasis is devoted to the relation between the coupling constant in the MOM and $\overline{\rm{MS}}$ schemes as well as their ability to describe the phenomenon of decoupling. It is demonstrated by an explicit comparison that the $\overline{\rm{MS}}$ scheme can be consistently used to relate the values of the MOM-scheme strong-coupling constant in the energy regions higher and lower than the massive-quark production threshold. This procedure obviates the necessity to know the full mass dependence of the MOM $\beta$ function and clearly demonstrates the equivalence of both schemes for the description of physics outside the threshold region.
1209.0297
Konstantin Matchev
Stefan Ask, Neil D. Christensen, Claude Duhr, Christophe Grojean, Stefan Hoeche, Konstantin Matchev, Olivier Mattelaer, Stephen Mrenna, Andreas Papaefstathiou, Myeonghun Park, Maxim Perelstein, and Peter Skands
From Lagrangians to Events: Computer Tutorial at the MC4BSM-2012 Workshop
58 pages, 1 figure
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is a written account of the computer tutorial offered at the Sixth MC4BSM workshop at Cornell University, March 22-24, 2012. The tools covered during the tutorial include: FeynRules, LanHEP, MadGraph, CalcHEP, Pythia 8, Herwig++, and Sherpa. In the tutorial, we specify a simple extension of the Standard Model, at the level of a Lagrangian. The software tools are then used to automatically generate a set of Feynman rules, compute the invariant matrix element for a sample process, and generate both parton-level and fully hadronized/showered Monte Carlo event samples. The tutorial is designed to be self-paced, and detailed instructions for all steps are included in this write-up. Installation instructions for each tool on a variety of popular platforms are also provided.
[ { "created": "Mon, 3 Sep 2012 10:34:58 GMT", "version": "v1" } ]
2012-09-04
[ [ "Ask", "Stefan", "" ], [ "Christensen", "Neil D.", "" ], [ "Duhr", "Claude", "" ], [ "Grojean", "Christophe", "" ], [ "Hoeche", "Stefan", "" ], [ "Matchev", "Konstantin", "" ], [ "Mattelaer", "Olivier", "" ], [ "Mrenna", "Stephen", "" ], [ "Papaefstathiou", "Andreas", "" ], [ "Park", "Myeonghun", "" ], [ "Perelstein", "Maxim", "" ], [ "Skands", "Peter", "" ] ]
This is a written account of the computer tutorial offered at the Sixth MC4BSM workshop at Cornell University, March 22-24, 2012. The tools covered during the tutorial include: FeynRules, LanHEP, MadGraph, CalcHEP, Pythia 8, Herwig++, and Sherpa. In the tutorial, we specify a simple extension of the Standard Model, at the level of a Lagrangian. The software tools are then used to automatically generate a set of Feynman rules, compute the invariant matrix element for a sample process, and generate both parton-level and fully hadronized/showered Monte Carlo event samples. The tutorial is designed to be self-paced, and detailed instructions for all steps are included in this write-up. Installation instructions for each tool on a variety of popular platforms are also provided.
1902.00886
Jorge L\'opez
William K Brooks and Jorge L\'opez
Propagation of QCD Color through Strongly Interacting Systems
4 pages, 3 figures; proceedings for the Eighth International Conference on Quarks and Nuclear Physics (QNP2018), Tsukuba, Japan. https://www-conf.kek.jp/qnp2018/
null
10.7566/JPSCP.26.024008
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The propagation of QCD color through atomic nuclei is studied via a new analysis using a geometric model of semi-inclusive deep inelastic scattering. The experimental data were previously published by the HERMES Collaboration and consisted of the multiplicity ratio observable (2007) and the transverse momentum broadening observable (2010). We perform a simultaneous fit of these two observables to estimate (1) the color lifetime of the quark, (2) quark energy loss, (3) the $\hat{q}$ transport coefficient, and (4) the cross section for hadronic interaction with the medium. We present preliminary results for this fit.
[ { "created": "Sun, 3 Feb 2019 12:20:38 GMT", "version": "v1" }, { "created": "Thu, 8 Aug 2019 02:24:01 GMT", "version": "v2" } ]
2020-01-08
[ [ "Brooks", "William K", "" ], [ "López", "Jorge", "" ] ]
The propagation of QCD color through atomic nuclei is studied via a new analysis using a geometric model of semi-inclusive deep inelastic scattering. The experimental data were previously published by the HERMES Collaboration and consisted of the multiplicity ratio observable (2007) and the transverse momentum broadening observable (2010). We perform a simultaneous fit of these two observables to estimate (1) the color lifetime of the quark, (2) quark energy loss, (3) the $\hat{q}$ transport coefficient, and (4) the cross section for hadronic interaction with the medium. We present preliminary results for this fit.
hep-ph/0206289
Igor Shovkovy
V. P. Gusynin, V. A. Miransky and I. A. Shovkovy
Comment on ``Electron Mass Operator in a Strong Magnetic Field and Dynamical Chiral Symmetry Breaking"
2 pages, REVTeX
Phys.Rev.Lett. 90 (2003) 089101
10.1103/PhysRevLett.90.089101
null
hep-ph
null
This is a comment on the paper ``Electron Mass Operator in a Strong Magnetic Field and Dynamical Chiral Symmetry Breaking" by A. V. Kuznetsov and N. V. Mikheev [Phys. Rev. Lett. 89 (2002) 011601]. We show that the main conclusions of the paper are incorrect.
[ { "created": "Thu, 27 Jun 2002 17:41:06 GMT", "version": "v1" } ]
2009-11-07
[ [ "Gusynin", "V. P.", "" ], [ "Miransky", "V. A.", "" ], [ "Shovkovy", "I. A.", "" ] ]
This is a comment on the paper ``Electron Mass Operator in a Strong Magnetic Field and Dynamical Chiral Symmetry Breaking" by A. V. Kuznetsov and N. V. Mikheev [Phys. Rev. Lett. 89 (2002) 011601]. We show that the main conclusions of the paper are incorrect.
1201.4741
Ali Alavi
S. A. Alavi, A. Abbasnezhad
Can Gravity Distinguish between Dirac and Majorana Neutrinos?
23 pages, 18 diagrams, 3 Figures, Replaced with the version published in Gravitation and Cosmology
Gravitation and Cosmology July 2016, Volume 22, Issue 3, pp 288-298
10.1134/S0202289316030038
null
hep-ph astro-ph.HE gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The interaction of neutrinos with gravitational fields in the weak field regime at one loop to the leading order has been studied by Menon and Thalappilil. They deduced some theoretical differences between the Majorana and Dirac neutrinos. Then they proved that, in spite of these theoretical differences, as far as experiments are concerned, they would be virtually indistinguishable. We study the interaction of neutrinos with weak gravitational fields to the second order (at two loops). We show that there appear new neutrino gravitational form factors which were absent in the first-order calculations, so from a theoretical point of view there are more differences between the two kinds of neutrinos than in the first order, but we show that likewise they are indistinguishable experimentally.
[ { "created": "Mon, 23 Jan 2012 15:24:46 GMT", "version": "v1" }, { "created": "Sun, 21 Jun 2015 10:06:03 GMT", "version": "v2" }, { "created": "Sun, 14 Aug 2016 06:47:49 GMT", "version": "v3" } ]
2016-08-16
[ [ "Alavi", "S. A.", "" ], [ "Abbasnezhad", "A.", "" ] ]
The interaction of neutrinos with gravitational fields in the weak field regime at one loop to the leading order has been studied by Menon and Thalappilil. They deduced some theoretical differences between the Majorana and Dirac neutrinos. Then they proved that, in spite of these theoretical differences, as far as experiments are concerned, they would be virtually indistinguishable. We study the interaction of neutrinos with weak gravitational fields to the second order (at two loops). We show that there appear new neutrino gravitational form factors which were absent in the first-order calculations, so from a theoretical point of view there are more differences between the two kinds of neutrinos than in the first order, but we show that likewise they are indistinguishable experimentally.
2209.07906
Artur E. Semushin
Artur E. Semushin, Evgeny Yu. Soldatov
Study of corrections for anomalous coupling limits due to the possible background BSM contributions
13 pages, 4 figures, 4 tables. Published in Symmetry
Symmetry 14 (2022) 10,2082
10.3390/sym14102082
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
The search of the anomalous couplings is one of the possible ways to find any deviation from the Standard Model. The effective field theory is used to parameterize the anomalous couplings in the Lagrangian with the operators of higher dimensions, constructed from the SM fields. In the classical way, the limits on the Wilson coefficients of these operators are set based on beyond the Standard Model contributions induced for signal process, whereas the ones induced for background processes are assumed to be negligible. This article provides a study of the corrections to the limits on Wilson coefficients by accounting beyond the Standard Model contributions induced for background processes. The studies of $Z(\nu\bar{\nu})\gamma jj$ and $W(\ell\nu)\gamma jj$ productions in $pp$ collisions with $\sqrt{s}=13$ TeV and conditions of the ATLAS experiment at the LHC are used as example. Cases of collected during Run II and expected from Run III integrated luminosities of 139 fb$^{-1}$ and 300 fb$^{-1}$ are considered. The expected 95% CL limits on coefficients $f_\text{T0}/\Lambda^4$, $f_\text{T5}/\Lambda^4$, $f_\text{M0}/\Lambda^4$ and $f_\text{M2}/\Lambda^4$ are obtained both in classical way and in the way, where the corrections from background anomalous contributions are applied. Corrected one-dimensional limits from $Z(\nu\bar{\nu})\gamma jj$ and $W(\ell\nu)\gamma jj$ productions are up to 9.1% and 4.4% (depending on operator) tighter than the classical ones respectively. Corrected combined limits are up to 3.0% (depending on operator) tighter than the classical ones. Corrections to two-dimensional limits are also obtained, corrected contours are more stringent, than the classical ones, and the maximal improvement is of 17.2%.
[ { "created": "Fri, 16 Sep 2022 13:07:46 GMT", "version": "v1" }, { "created": "Wed, 23 Nov 2022 07:58:27 GMT", "version": "v2" } ]
2022-11-24
[ [ "Semushin", "Artur E.", "" ], [ "Soldatov", "Evgeny Yu.", "" ] ]
The search of the anomalous couplings is one of the possible ways to find any deviation from the Standard Model. The effective field theory is used to parameterize the anomalous couplings in the Lagrangian with the operators of higher dimensions, constructed from the SM fields. In the classical way, the limits on the Wilson coefficients of these operators are set based on beyond the Standard Model contributions induced for signal process, whereas the ones induced for background processes are assumed to be negligible. This article provides a study of the corrections to the limits on Wilson coefficients by accounting beyond the Standard Model contributions induced for background processes. The studies of $Z(\nu\bar{\nu})\gamma jj$ and $W(\ell\nu)\gamma jj$ productions in $pp$ collisions with $\sqrt{s}=13$ TeV and conditions of the ATLAS experiment at the LHC are used as example. Cases of collected during Run II and expected from Run III integrated luminosities of 139 fb$^{-1}$ and 300 fb$^{-1}$ are considered. The expected 95% CL limits on coefficients $f_\text{T0}/\Lambda^4$, $f_\text{T5}/\Lambda^4$, $f_\text{M0}/\Lambda^4$ and $f_\text{M2}/\Lambda^4$ are obtained both in classical way and in the way, where the corrections from background anomalous contributions are applied. Corrected one-dimensional limits from $Z(\nu\bar{\nu})\gamma jj$ and $W(\ell\nu)\gamma jj$ productions are up to 9.1% and 4.4% (depending on operator) tighter than the classical ones respectively. Corrected combined limits are up to 3.0% (depending on operator) tighter than the classical ones. Corrections to two-dimensional limits are also obtained, corrected contours are more stringent, than the classical ones, and the maximal improvement is of 17.2%.
1712.02955
Xian-Qiao Yu
Feng Bo Duan, Xian-Qiao Yu
Study of $B_{c} \rightarrow \psi(2S) K$, $\eta_{c}(2S)K$, $\psi(3770)K$ decays with perturbative QCD approach
12pages, 2 figures
Phys. Rev. D 97, 096008 (2018)
10.1103/PhysRevD.97.096008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the $B_{c}$$\rightarrow$$\psi(2S)$K, $\eta_{c}(2S)$K, $\psi(3770)$K decays with perturbative QCD approach (pQCD) based on $k_T$ factorization. The new orbitally excited charmonium distribution amplitudes $\psi(1^{3}D_{1})$ based on the Schr\"{o}dinger wave function of the $n=1$, $l=2$ state for the harmonic-oscillator potential are employed. By using the corresponding distribution amplitudes, we calculate the branching ratio of $B_{c}$$\rightarrow$$\psi(2S)$K, $\eta_{c}(2S)$K, $\psi(3770)$K decays and the form factors $A_{0,1,2}$ and $V$ for the transition $B_{c}$$\rightarrow$$\psi(1^{3}D_{1})$. We obtain the branching ratio of both $B_{c}$$\rightarrow$$\psi(2S)$K and $B_{c}$$\rightarrow$$\eta_{c}(2S)$K are at the order of $10^{-5}$. The effects of two sets of the S-D mixing angle $\theta=-12^{\circ}$ and $\theta=27^{\circ}$ for the decay $B_{c}$$\rightarrow$$\psi(3770)$K are studied firstly in this paper. Our calculations show that the branching ratio of the decay $B_{c}$$\rightarrow$$\psi(3770)$K can be raised from the order of $10^{-6}$ to the order of $10^{-5}$ at the mixing angle $\theta=-12^{\circ}$, which can be tested by the running LHC-b experiments.
[ { "created": "Fri, 8 Dec 2017 06:21:45 GMT", "version": "v1" }, { "created": "Sat, 19 May 2018 03:48:22 GMT", "version": "v2" } ]
2018-05-23
[ [ "Duan", "Feng Bo", "" ], [ "Yu", "Xian-Qiao", "" ] ]
We study the $B_{c}$$\rightarrow$$\psi(2S)$K, $\eta_{c}(2S)$K, $\psi(3770)$K decays with perturbative QCD approach (pQCD) based on $k_T$ factorization. The new orbitally excited charmonium distribution amplitudes $\psi(1^{3}D_{1})$ based on the Schr\"{o}dinger wave function of the $n=1$, $l=2$ state for the harmonic-oscillator potential are employed. By using the corresponding distribution amplitudes, we calculate the branching ratio of $B_{c}$$\rightarrow$$\psi(2S)$K, $\eta_{c}(2S)$K, $\psi(3770)$K decays and the form factors $A_{0,1,2}$ and $V$ for the transition $B_{c}$$\rightarrow$$\psi(1^{3}D_{1})$. We obtain the branching ratio of both $B_{c}$$\rightarrow$$\psi(2S)$K and $B_{c}$$\rightarrow$$\eta_{c}(2S)$K are at the order of $10^{-5}$. The effects of two sets of the S-D mixing angle $\theta=-12^{\circ}$ and $\theta=27^{\circ}$ for the decay $B_{c}$$\rightarrow$$\psi(3770)$K are studied firstly in this paper. Our calculations show that the branching ratio of the decay $B_{c}$$\rightarrow$$\psi(3770)$K can be raised from the order of $10^{-6}$ to the order of $10^{-5}$ at the mixing angle $\theta=-12^{\circ}$, which can be tested by the running LHC-b experiments.
2106.05331
Rene Poncelet
Michal Czakon, Alexander Mitov, Rene Poncelet
A first next-to-next-to-leading order study of three-jet production at the LHC
5 pages, 6 figures, In the original publication, we have evaluated the two-loop finite remainder function with an incorrect colour factor. The updated version of the paper contains the corrected plots and correspondingly updated statements in the text
Phys. Rev. Lett. 127, 152001 (2021)
10.1103/PhysRevLett.127.152001
Cavendish-HEP-21/09, P3H-21-043, TTK-21-20
hep-ph hep-ex hep-th
http://creativecommons.org/licenses/by/4.0/
Multi-jet rates at hadron colliders provide a unique possibility for probing Quantum Chromodynamics (QCD), the theory of strong interactions. By comparing theory predictions with collider data, one can directly test perturbative QCD, extract fundamental parameters like the strong coupling $\alpha_s$ and search for physics beyond the Standard Model. In this work we calculate, for the first time, the next-to-next-to-leading (NNLO) QCD corrections to typical three-jet observables and to differential three-to-two jet ratios. We demonstrate that the inclusion of the NNLO corrections significantly reduces the dependence of those observables on the factorization and renormalization scales. Besides its phenomenological value, this proof-of-principle computation represents a milestone in perturbative QCD.
[ { "created": "Wed, 9 Jun 2021 18:42:58 GMT", "version": "v1" }, { "created": "Fri, 26 Aug 2022 18:36:42 GMT", "version": "v2" } ]
2022-08-30
[ [ "Czakon", "Michal", "" ], [ "Mitov", "Alexander", "" ], [ "Poncelet", "Rene", "" ] ]
Multi-jet rates at hadron colliders provide a unique possibility for probing Quantum Chromodynamics (QCD), the theory of strong interactions. By comparing theory predictions with collider data, one can directly test perturbative QCD, extract fundamental parameters like the strong coupling $\alpha_s$ and search for physics beyond the Standard Model. In this work we calculate, for the first time, the next-to-next-to-leading (NNLO) QCD corrections to typical three-jet observables and to differential three-to-two jet ratios. We demonstrate that the inclusion of the NNLO corrections significantly reduces the dependence of those observables on the factorization and renormalization scales. Besides its phenomenological value, this proof-of-principle computation represents a milestone in perturbative QCD.
1903.09771
Madhurjya Lalung
M. Lalung, P. Phukan, J. K. Sarma
Small-x analysis on the effect of gluon recombinations inside hadrons in light of the GLR-MQ-ZRS equation
24 pages, 7 figures, new references added, new text added in the Introduction and the Results and Discussion section, Accepted for publication in Nuclear Physics A
Nuclear Physics A 992, 121615 (2019)
10.1016/j.nuclphysa.2019.121615
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present a study of the contribution of antishadowing effects on the gluon distribution functions $G(x,Q^2)$ in light of the Gribov-Levin-Ryskin-Mueller-Qiu, Zhu-Ruan-Shen (GLR-MQ-ZRS) nonlinear equation at small-$x$, where $x$ is the momentum fraction or Bjorken variable and $Q^2$ is the four momentum transfer squared or photon virtuality. In this work, we have solved the GLR-MQ-ZRS nonlinear equation using Regge like the behavior of gluons in the kinematic range of $10^{-2}\leq x \leq 10^{-6}$ and $5\,GeV^2\, \leq Q^2\leq 100\, GeV^2$ respectively. We have obtained the solution of $G(x,Q^2)$ by considering two particular cases: (a) $\alpha_s$ fixed; and (b) the leading order QCD dependency of $\alpha_{s}$ on $Q^2$. A comparative analysis is also performed where we compare the gluon distribution function due to inclusion of the antishadowing effect with that of the gluon distribution without including the antishadowing effect. Our obtained results of $G(x,Q^2)$ are compared with NNPDF3.0, CT14 and PDF4LHC. We also compare our results with the result obtained from the IMParton C++ package. Using the solutions of $G(x,Q^2)$, we have also predicted $x$ and $Q^2$ evolution of the logarithmic derivative of proton's $F_2$ structure function i.e. $dF_2 (x,Q^2)/d\ln Q^2$. We incorporated both the leading order(LO) and next-to-leading order (NLO) QCD contributions of the gluon-quark splitting kernels, in $dF_2 (x,Q^2)/d\ln Q^2$. Our result of $dF_2 (x,Q^2)/d\ln Q^2$ agrees reasonably well with the experimental data recorded by HERA's H1 detector.
[ { "created": "Sat, 23 Mar 2019 06:45:17 GMT", "version": "v1" }, { "created": "Mon, 19 Aug 2019 05:13:26 GMT", "version": "v2" } ]
2019-09-25
[ [ "Lalung", "M.", "" ], [ "Phukan", "P.", "" ], [ "Sarma", "J. K.", "" ] ]
We present a study of the contribution of antishadowing effects on the gluon distribution functions $G(x,Q^2)$ in light of the Gribov-Levin-Ryskin-Mueller-Qiu, Zhu-Ruan-Shen (GLR-MQ-ZRS) nonlinear equation at small-$x$, where $x$ is the momentum fraction or Bjorken variable and $Q^2$ is the four momentum transfer squared or photon virtuality. In this work, we have solved the GLR-MQ-ZRS nonlinear equation using Regge like the behavior of gluons in the kinematic range of $10^{-2}\leq x \leq 10^{-6}$ and $5\,GeV^2\, \leq Q^2\leq 100\, GeV^2$ respectively. We have obtained the solution of $G(x,Q^2)$ by considering two particular cases: (a) $\alpha_s$ fixed; and (b) the leading order QCD dependency of $\alpha_{s}$ on $Q^2$. A comparative analysis is also performed where we compare the gluon distribution function due to inclusion of the antishadowing effect with that of the gluon distribution without including the antishadowing effect. Our obtained results of $G(x,Q^2)$ are compared with NNPDF3.0, CT14 and PDF4LHC. We also compare our results with the result obtained from the IMParton C++ package. Using the solutions of $G(x,Q^2)$, we have also predicted $x$ and $Q^2$ evolution of the logarithmic derivative of proton's $F_2$ structure function i.e. $dF_2 (x,Q^2)/d\ln Q^2$. We incorporated both the leading order(LO) and next-to-leading order (NLO) QCD contributions of the gluon-quark splitting kernels, in $dF_2 (x,Q^2)/d\ln Q^2$. Our result of $dF_2 (x,Q^2)/d\ln Q^2$ agrees reasonably well with the experimental data recorded by HERA's H1 detector.
2204.01655
Fabio L. Braghin
Igor de M. Froldi, Fabio L. Braghin
Classical Yang Mills equations with sources: consequences of specific scalar potentials
33 pages, 29 figures, improved sentences, few references included and some misprints corrected
Ann. of Phys. 444 (2022) 169026
10.1016/j.aop.2022.169026
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Some well known gauge scalar potential very often considered or used in the literature are investigated by means of the classical Yang Mills equations for the $SU(2)$ subgroups of $N_c=3$. By fixing a particular shape for the scalar potential, the resulting vector potentials and the corresponding color-charges sources are found. By adopting the spherical coordinate system, it is shown that spherically symmetric solutions, only dependent on the radial coordinate, are only possible for the Abelian limit, otherwise, there must have angle-dependent component(s). The following solutions for the scalar potential are investigated: the Coulomb potential and a non-spherically symmetric generalization, a linear potential $A_0 (\vec{r}) \sim (\kappa r)$, a Yukawa-type potential $A_0 (\vec{r}) \sim (C e^{-r/r_0}/r)$ and finite spatial regions in which the scalar potential assumes constant values. The corresponding chromo-electric and chromo-magnetic fields, as well as the color-charge densities, are found to have strong deviations from the spherical symmetric configurations. We speculate these types of non-spherically symmetric configurations may contribute (or favor) for the (anisotropic) confinement mechanism since they should favor color charge-anti-charge (or three-color-charge) bound states that are intrinsically non spherically symmetric with (asymmetric) confinement of fluxes. Specific conditions and relations between the parameters of the solutions are also presented.
[ { "created": "Mon, 4 Apr 2022 17:03:58 GMT", "version": "v1" }, { "created": "Mon, 18 Apr 2022 17:37:03 GMT", "version": "v2" } ]
2022-08-02
[ [ "Froldi", "Igor de M.", "" ], [ "Braghin", "Fabio L.", "" ] ]
Some well known gauge scalar potential very often considered or used in the literature are investigated by means of the classical Yang Mills equations for the $SU(2)$ subgroups of $N_c=3$. By fixing a particular shape for the scalar potential, the resulting vector potentials and the corresponding color-charges sources are found. By adopting the spherical coordinate system, it is shown that spherically symmetric solutions, only dependent on the radial coordinate, are only possible for the Abelian limit, otherwise, there must have angle-dependent component(s). The following solutions for the scalar potential are investigated: the Coulomb potential and a non-spherically symmetric generalization, a linear potential $A_0 (\vec{r}) \sim (\kappa r)$, a Yukawa-type potential $A_0 (\vec{r}) \sim (C e^{-r/r_0}/r)$ and finite spatial regions in which the scalar potential assumes constant values. The corresponding chromo-electric and chromo-magnetic fields, as well as the color-charge densities, are found to have strong deviations from the spherical symmetric configurations. We speculate these types of non-spherically symmetric configurations may contribute (or favor) for the (anisotropic) confinement mechanism since they should favor color charge-anti-charge (or three-color-charge) bound states that are intrinsically non spherically symmetric with (asymmetric) confinement of fluxes. Specific conditions and relations between the parameters of the solutions are also presented.
hep-ph/9607475
Dr Philip "R." Page
Philip R. Page
Two Photon Couplings of Hybrid Mesons
15 pages, LaTeX, 2 postscript figures, uses epsf. Rewritten for clarification
Nucl.Phys. B495 (1997) 268-282
10.1016/S0550-3213(97)00191-0
null
hep-ph
null
A new formalism is developed for the two photon production of hybrid mesons via intermediate hadronic decays. In an adiabatic and non-relativistic context with spin 1 pair creation we obtain the first absolute estimates of unmixed hybrid production strengths to be small (0.03 - 3 eV) in relation to experimental meson widths (0.1 - 5 keV). Within this context, two photon experiments at Babar, Cleo II, LEP2 and LHC therefore strongly discriminate between hybrid and conventional meson wave function components, filtering out conventional meson components. Decay widths of unmixed hybrids vanish. Conventional meson two photon widths are roughly in agreement with experiment.
[ { "created": "Wed, 31 Jul 1996 11:23:05 GMT", "version": "v1" }, { "created": "Wed, 9 Apr 1997 22:09:55 GMT", "version": "v2" } ]
2009-10-28
[ [ "Page", "Philip R.", "" ] ]
A new formalism is developed for the two photon production of hybrid mesons via intermediate hadronic decays. In an adiabatic and non-relativistic context with spin 1 pair creation we obtain the first absolute estimates of unmixed hybrid production strengths to be small (0.03 - 3 eV) in relation to experimental meson widths (0.1 - 5 keV). Within this context, two photon experiments at Babar, Cleo II, LEP2 and LHC therefore strongly discriminate between hybrid and conventional meson wave function components, filtering out conventional meson components. Decay widths of unmixed hybrids vanish. Conventional meson two photon widths are roughly in agreement with experiment.
1011.5518
Tong Li
M. Adeel Ajaib, Tong Li, Qaisar Shafi, Kai Wang
NLSP Gluino Search at the Tevatron and early LHC
14 pages, 4 figures and 3 tables, minor modifications made and accepted for publication in JHEP
JHEP 1101:028,2011
10.1007/JHEP01(2011)028
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the collider phenomenology of gluino-bino co-annihilation scenario both at the Tevatron and 7 TeV LHC. This scenario can be realized, for example, in a class of realistic supersymmetric models with non-universal gaugino masses and t-b-\tau Yukawa unification. The NLSP gluino and LSP bino should be nearly degenerate in mass, so that the typical gluino search channels involving leptons or hard jets are not available. Consequently, the gluino can be lighter than various bounds on its mass from direct searches. We propose a new search for NLSP gluino involving multi-b final states, arising from the three-body decay \tilde{g}-> b\bar{b}\tilde{\chi}_1^0. We identify two realistic models with gluino mass of around 300 GeV for which the three-body decay is dominant, and show that a 4.5 \sigma observation sensitivity can be achieved at the Tevatron with an integrated luminosity of 10 fb^{-1}. For the 7 TeV LHC with 50 pb^{-1} of integrated luminosity, the number of signal events for the two models is O(10), to be compared with negligible SM background event.
[ { "created": "Wed, 24 Nov 2010 21:44:54 GMT", "version": "v1" }, { "created": "Wed, 29 Dec 2010 21:53:53 GMT", "version": "v2" } ]
2011-01-27
[ [ "Ajaib", "M. Adeel", "" ], [ "Li", "Tong", "" ], [ "Shafi", "Qaisar", "" ], [ "Wang", "Kai", "" ] ]
We investigate the collider phenomenology of gluino-bino co-annihilation scenario both at the Tevatron and 7 TeV LHC. This scenario can be realized, for example, in a class of realistic supersymmetric models with non-universal gaugino masses and t-b-\tau Yukawa unification. The NLSP gluino and LSP bino should be nearly degenerate in mass, so that the typical gluino search channels involving leptons or hard jets are not available. Consequently, the gluino can be lighter than various bounds on its mass from direct searches. We propose a new search for NLSP gluino involving multi-b final states, arising from the three-body decay \tilde{g}-> b\bar{b}\tilde{\chi}_1^0. We identify two realistic models with gluino mass of around 300 GeV for which the three-body decay is dominant, and show that a 4.5 \sigma observation sensitivity can be achieved at the Tevatron with an integrated luminosity of 10 fb^{-1}. For the 7 TeV LHC with 50 pb^{-1} of integrated luminosity, the number of signal events for the two models is O(10), to be compared with negligible SM background event.
hep-ph/0303080
Andreas Ringwald
Z. Fodor, S. D. Katz, A. Ringwald, H. Tu
Electroweak instantons as a solution to the ultrahigh energy cosmic ray puzzle
14 pages, 7 figures
Phys.Lett. B561 (2003) 191-201
10.1016/S0370-2693(03)00487-8
WUB 03-03, ITP-BUDAPEST 593, DESY 03-022
hep-ph astro-ph
null
We propose a scenario in which a simple power-like primary spectrum for protons with sources at cosmological distances leads to a quantitative description of all the details of the observed cosmic ray spectrum for energies from 10^{17} eV to 10^{21} eV. As usual, the ultrahigh energy protons with energies above E_{GZK} ~ 4 x 10^{19} eV loose a large fraction of their energies by the photoproduction of pions on the cosmic microwave background, which finally decay mainly into neutrinos. In our scenario, these so-called cosmogenic neutrinos interact with nucleons in the atmosphere through Standard Model electroweak instanton-induced processes and produce air showers which are hardly distinguishable from ordinary hadron-initiated air showers. In this way, they give rise to a second contribution to the observed cosmic ray spectrum -- in addition to the one from above mentioned protons -- which reaches beyond E_{GZK}. Since the whole observed spectrum is uniquely determined by a single primary injection spectrum, no fine tuning is needed to fix the ratio of the spectra below and above E_{GZK}. The statistical analysis shows an excellent goodness of this scenario. Possible tests of it range from observations at cosmic ray facilities and neutrino telescopes to searches for QCD instanton-induced processes at HERA.
[ { "created": "Mon, 10 Mar 2003 16:38:56 GMT", "version": "v1" } ]
2009-11-10
[ [ "Fodor", "Z.", "" ], [ "Katz", "S. D.", "" ], [ "Ringwald", "A.", "" ], [ "Tu", "H.", "" ] ]
We propose a scenario in which a simple power-like primary spectrum for protons with sources at cosmological distances leads to a quantitative description of all the details of the observed cosmic ray spectrum for energies from 10^{17} eV to 10^{21} eV. As usual, the ultrahigh energy protons with energies above E_{GZK} ~ 4 x 10^{19} eV loose a large fraction of their energies by the photoproduction of pions on the cosmic microwave background, which finally decay mainly into neutrinos. In our scenario, these so-called cosmogenic neutrinos interact with nucleons in the atmosphere through Standard Model electroweak instanton-induced processes and produce air showers which are hardly distinguishable from ordinary hadron-initiated air showers. In this way, they give rise to a second contribution to the observed cosmic ray spectrum -- in addition to the one from above mentioned protons -- which reaches beyond E_{GZK}. Since the whole observed spectrum is uniquely determined by a single primary injection spectrum, no fine tuning is needed to fix the ratio of the spectra below and above E_{GZK}. The statistical analysis shows an excellent goodness of this scenario. Possible tests of it range from observations at cosmic ray facilities and neutrino telescopes to searches for QCD instanton-induced processes at HERA.
0903.4677
David G. Cerdeno
David G. Cerdeno, Osamu Seto
Right-handed sneutrino dark matter in the NMSSM
LaTeX, 59 pages, 20 figures
JCAP 0908:032,2009
10.1088/1475-7516/2009/08/032
FTUAM 09/5, IFT-UAM/CSIC-09-17, FTPI-MINN-09-14, UMN-TH-2742/09
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the properties of the right-handed sneutrino and its viability as a WIMP dark matter candidate in an extended version of the NMSSM in which a right-handed neutrino superfield is included with a coupling to the singlet Higgs in order to provide non-vanishing Majorana neutrino masses. We perform a systematic study of the parameter space, including LEP constraints and experimental bounds on low-energy observables. We investigate the conditions under which the right-handed sneutrino has the correct relic abundance and the dominant annihilation channels. Next we calculate the theoretical predictions for the sneutrino-proton elastic scattering cross section and compare it with present and future experimental sensitivities. We find that sneutrinos with a mass in the range of 5-200 GeV can reproduce the observed dark matter relic density without being excluded by direct dark matter searches and for natural values of the input parameters. Interestingly, the predicted scattering cross section is generally within the reach of future experiments. Finally, we comment on the possible implications for collider physics.
[ { "created": "Thu, 26 Mar 2009 19:36:17 GMT", "version": "v1" } ]
2009-09-28
[ [ "Cerdeno", "David G.", "" ], [ "Seto", "Osamu", "" ] ]
We study the properties of the right-handed sneutrino and its viability as a WIMP dark matter candidate in an extended version of the NMSSM in which a right-handed neutrino superfield is included with a coupling to the singlet Higgs in order to provide non-vanishing Majorana neutrino masses. We perform a systematic study of the parameter space, including LEP constraints and experimental bounds on low-energy observables. We investigate the conditions under which the right-handed sneutrino has the correct relic abundance and the dominant annihilation channels. Next we calculate the theoretical predictions for the sneutrino-proton elastic scattering cross section and compare it with present and future experimental sensitivities. We find that sneutrinos with a mass in the range of 5-200 GeV can reproduce the observed dark matter relic density without being excluded by direct dark matter searches and for natural values of the input parameters. Interestingly, the predicted scattering cross section is generally within the reach of future experiments. Finally, we comment on the possible implications for collider physics.