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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1805.11717 | Pasquale Di Bari | Marco Chianese, Pasquale Di Bari, Kareem Farrag and Rome Samanta | Probing relic neutrino decays with 21 cm cosmology | 18 pages. 2 figures; v2: It matches PLB version | null | 10.1016/j.physletb.2018.09.040 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show how 21 cm cosmology can test relic neutrino radiative decays into
sterile neutrinos. Using recent EDGES results, we derive constraints on the
lifetime of the decaying neutrinos. If the EDGES anomaly will be confirmed,
then there are two solutions, one for much longer and one for much shorter
lifetimes than the age of the universe, showing how relic neutrino radiative
decays can explain the anomaly in a simple way. We also show how to combine
EDGES results with those from radio background observations, showing that
potentially the ARCADE 2 excess can be also reproduced together with the EDGES
anomaly within the proposed non-standard cosmological scenario. Our calculation
of the specific intensity at the redshifts probed by EDGES can be also applied
to the case of decaying dark matter and it also corrects a flawed expression
appeared in previous literature.
| [
{
"created": "Tue, 29 May 2018 21:34:25 GMT",
"version": "v1"
},
{
"created": "Thu, 20 Sep 2018 16:28:32 GMT",
"version": "v2"
}
] | 2018-10-29 | [
[
"Chianese",
"Marco",
""
],
[
"Di Bari",
"Pasquale",
""
],
[
"Farrag",
"Kareem",
""
],
[
"Samanta",
"Rome",
""
]
] | We show how 21 cm cosmology can test relic neutrino radiative decays into sterile neutrinos. Using recent EDGES results, we derive constraints on the lifetime of the decaying neutrinos. If the EDGES anomaly will be confirmed, then there are two solutions, one for much longer and one for much shorter lifetimes than the age of the universe, showing how relic neutrino radiative decays can explain the anomaly in a simple way. We also show how to combine EDGES results with those from radio background observations, showing that potentially the ARCADE 2 excess can be also reproduced together with the EDGES anomaly within the proposed non-standard cosmological scenario. Our calculation of the specific intensity at the redshifts probed by EDGES can be also applied to the case of decaying dark matter and it also corrects a flawed expression appeared in previous literature. |
hep-ph/9507217 | Vladimir A. Saleev | V.Saleev | Charm Photoproduction At Large Transverse Momentum And The Charm Content
Of The Photon | LaTeX, 4 pages, 4 figures are not included | null | null | SSU-HEP-95/04 | hep-ph | null | The charm quark photoproduction at large transverse momentum in the resolved
photon interaction via partonic subprocess $\cg$ is studied. It is shown that
at HERA energies the contribution of the charm quark excitation in the photon
in the inclusive charm production at $\pt>5$ GeV/c dominates over the other
resolved photon contribution via the gluon content of the photon and it is
about 30\% of the contribution of the $c\bar c$-pair production via the
photon-gluon fusion mechanism.
| [
{
"created": "Tue, 4 Jul 1995 07:18:56 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Saleev",
"V.",
""
]
] | The charm quark photoproduction at large transverse momentum in the resolved photon interaction via partonic subprocess $\cg$ is studied. It is shown that at HERA energies the contribution of the charm quark excitation in the photon in the inclusive charm production at $\pt>5$ GeV/c dominates over the other resolved photon contribution via the gluon content of the photon and it is about 30\% of the contribution of the $c\bar c$-pair production via the photon-gluon fusion mechanism. |
1911.08495 | Yehonatan Viernik | Elina Fuchs, Marta Losada, Yosef Nir and Yehonatan Viernik | Implications of the upper bound on $\boldsymbol{h\to\mu^+\mu^-}$ on the
baryon asymmetry of the Universe | 5 pages, 1 figure | Phys. Rev. Lett. 124, 181801 (2020) | 10.1103/PhysRevLett.124.181801 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The upper bounds from the ATLAS and CMS experiments on the decay rate of the
Higgs boson to two muons provide the strongest constraint on an imaginary part
of the muon Yukawa coupling. This bound is more than an order of magnitude
stronger than bounds from $\mathcal{CP}$-violating observables, specifically
the electric dipole moment of the electron. It excludes a scenario $-$ which
had been viable prior to these measurements $-$ that a complex muon Yukawa
coupling is the dominant source of the baryon asymmetry. Even with this bound,
the muon source can still contribute ${\cal O}(16\%)$ of the asymmetry.
| [
{
"created": "Tue, 19 Nov 2019 19:00:02 GMT",
"version": "v1"
},
{
"created": "Fri, 20 Dec 2019 11:19:34 GMT",
"version": "v2"
},
{
"created": "Tue, 14 Jul 2020 16:28:01 GMT",
"version": "v3"
}
] | 2020-07-15 | [
[
"Fuchs",
"Elina",
""
],
[
"Losada",
"Marta",
""
],
[
"Nir",
"Yosef",
""
],
[
"Viernik",
"Yehonatan",
""
]
] | The upper bounds from the ATLAS and CMS experiments on the decay rate of the Higgs boson to two muons provide the strongest constraint on an imaginary part of the muon Yukawa coupling. This bound is more than an order of magnitude stronger than bounds from $\mathcal{CP}$-violating observables, specifically the electric dipole moment of the electron. It excludes a scenario $-$ which had been viable prior to these measurements $-$ that a complex muon Yukawa coupling is the dominant source of the baryon asymmetry. Even with this bound, the muon source can still contribute ${\cal O}(16\%)$ of the asymmetry. |
2204.10265 | Victor Baules | Victor Baules and Nobuchika Okada | Experimentally distinguishable origin for electroweak symmetry breaking | 12 pages, 4 figures | null | null | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We consider a classically conformal $U(1)$ gauge extension of the Standard
Model (SM), in which the $U(1)$ gauge symmetry is radiatively broken by the
Coleman-Weinberg mechanism. This breaking triggers the electroweak (EW)
symmetry breaking through a mixed quartic coupling between the $U(1)$ Higgs
field and the SM Higgs doublet. For two Higgs boson mass eigenstates after the
symmetry breaking, $h_1$ (SM-like Higgs boson) and $h_2$ (SM singlet-like Higgs
boson), we calculate the Higgs boson trilinear coupling ($g_{h_{1} h_{2}
h_{2}}$) in the model by setting the Higgs boson mass spectrum to be $M_{h_1} >
2 M_{h_2}$. For a common Higgs mass spectrum and mixing angle between two Higgs
fields, we find that $g_{h_{1} h_{2} h_{2}}$ in the classically conformal model
is highly suppressed compared to that calculated for the conventional Higgs
potential, where the $U(1)$ and EW symmetry breaking originate from the
negative squared masses for the Higgs fields at the tree-level. Thus, this
coupling suppression is a striking nature of the radiative origin of EW
symmetry breaking. We then consider how to distinguish this origin at the
proposed International Linear Collider (ILC) via precise measurements of
anomalous SM Higgs boson couplings and the search for anomalous SM Higgs boson
decay $h_1 \rightarrow h_2 h_2$ followed by $h_2 \to b \bar{b}$. We conclude
that once the anomalous couplings are measured at the ILC, the observation of
the anomalous Higgs boson decay is promising in the conventional Higgs
potential, while this decay process is highly suppressed and undetectable for
the classically conformal model.
| [
{
"created": "Thu, 21 Apr 2022 17:06:40 GMT",
"version": "v1"
}
] | 2022-04-22 | [
[
"Baules",
"Victor",
""
],
[
"Okada",
"Nobuchika",
""
]
] | We consider a classically conformal $U(1)$ gauge extension of the Standard Model (SM), in which the $U(1)$ gauge symmetry is radiatively broken by the Coleman-Weinberg mechanism. This breaking triggers the electroweak (EW) symmetry breaking through a mixed quartic coupling between the $U(1)$ Higgs field and the SM Higgs doublet. For two Higgs boson mass eigenstates after the symmetry breaking, $h_1$ (SM-like Higgs boson) and $h_2$ (SM singlet-like Higgs boson), we calculate the Higgs boson trilinear coupling ($g_{h_{1} h_{2} h_{2}}$) in the model by setting the Higgs boson mass spectrum to be $M_{h_1} > 2 M_{h_2}$. For a common Higgs mass spectrum and mixing angle between two Higgs fields, we find that $g_{h_{1} h_{2} h_{2}}$ in the classically conformal model is highly suppressed compared to that calculated for the conventional Higgs potential, where the $U(1)$ and EW symmetry breaking originate from the negative squared masses for the Higgs fields at the tree-level. Thus, this coupling suppression is a striking nature of the radiative origin of EW symmetry breaking. We then consider how to distinguish this origin at the proposed International Linear Collider (ILC) via precise measurements of anomalous SM Higgs boson couplings and the search for anomalous SM Higgs boson decay $h_1 \rightarrow h_2 h_2$ followed by $h_2 \to b \bar{b}$. We conclude that once the anomalous couplings are measured at the ILC, the observation of the anomalous Higgs boson decay is promising in the conventional Higgs potential, while this decay process is highly suppressed and undetectable for the classically conformal model. |
2211.01421 | Tilman Plehn | Tilman Plehn, Anja Butter, Barry Dillon, Theo Heimel, Claudius Krause,
and Ramon Winterhalder | Modern Machine Learning for LHC Physicists | Further expanded v3, we very much appreciate feedback | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Modern machine learning is transforming particle physics fast, bullying its
way into our numerical tool box. For young researchers it is crucial to stay on
top of this development, which means applying cutting-edge methods and tools to
the full range of LHC physics problems. These lecture notes lead students with
basic knowledge of particle physics and significant enthusiasm for machine
learning to relevant applications. They start with an LHC-specific motivation
and a non-standard introduction to neural networks and then cover
classification, unsupervised classification, generative networks, and inverse
problems. Two themes defining much of the discussion are well-defined loss
functions and uncertainty-aware networks. As part of the applications, the
notes include some aspects of theoretical LHC physics. All examples are chosen
from particle physics publications of the last few years.
| [
{
"created": "Wed, 2 Nov 2022 18:27:27 GMT",
"version": "v1"
},
{
"created": "Sun, 17 Mar 2024 20:25:51 GMT",
"version": "v2"
},
{
"created": "Fri, 12 Apr 2024 06:36:23 GMT",
"version": "v3"
}
] | 2024-04-15 | [
[
"Plehn",
"Tilman",
""
],
[
"Butter",
"Anja",
""
],
[
"Dillon",
"Barry",
""
],
[
"Heimel",
"Theo",
""
],
[
"Krause",
"Claudius",
""
],
[
"Winterhalder",
"Ramon",
""
]
] | Modern machine learning is transforming particle physics fast, bullying its way into our numerical tool box. For young researchers it is crucial to stay on top of this development, which means applying cutting-edge methods and tools to the full range of LHC physics problems. These lecture notes lead students with basic knowledge of particle physics and significant enthusiasm for machine learning to relevant applications. They start with an LHC-specific motivation and a non-standard introduction to neural networks and then cover classification, unsupervised classification, generative networks, and inverse problems. Two themes defining much of the discussion are well-defined loss functions and uncertainty-aware networks. As part of the applications, the notes include some aspects of theoretical LHC physics. All examples are chosen from particle physics publications of the last few years. |
0807.3307 | Alexandre Kisselev | A.V. Kisselev | Gravity effects in inclined air showers induced by cosmic neutrino | 10 pages, 3 figures; 2 figures, 4 references and corrections are
added | Open Astron.J.2:12-15,2009 | 10.2174/1874381100902010012 | null | hep-ph astro-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Randall-Sundrum model with a small curvature is considered in which
five-dimensional Planck scale lies in the TeV region, and a spectrum of
Kaluza-Klein gravitons reminds that in one flat extra dimension. The cross
sections for interactions of ultra-high energy cosmic neutrinos with nucleons
are calculated. It is shown that effects related with massive graviton
excitations can be detected in deeply penetrating inclined air showers induced
by these neutrinos. The expected number of air showers at the Auger Observatory
is estimated as a function of two parameters of the model.
| [
{
"created": "Mon, 21 Jul 2008 16:39:16 GMT",
"version": "v1"
},
{
"created": "Fri, 5 Sep 2008 10:21:37 GMT",
"version": "v2"
},
{
"created": "Tue, 9 Sep 2008 07:34:49 GMT",
"version": "v3"
}
] | 2009-06-22 | [
[
"Kisselev",
"A. V.",
""
]
] | The Randall-Sundrum model with a small curvature is considered in which five-dimensional Planck scale lies in the TeV region, and a spectrum of Kaluza-Klein gravitons reminds that in one flat extra dimension. The cross sections for interactions of ultra-high energy cosmic neutrinos with nucleons are calculated. It is shown that effects related with massive graviton excitations can be detected in deeply penetrating inclined air showers induced by these neutrinos. The expected number of air showers at the Auger Observatory is estimated as a function of two parameters of the model. |
1408.6699 | Andrew Fowlie Dr. | Andrew Fowlie and Luca Marzola | Testing quark mixing in minimal left-right symmetric models with
$b$-tags at the LHC | 14 pages, 4 figures. Matches version published in Nucl.Phys. B.
Expanded descriptions of figures but conclusions unchanged | Nucl.Phys. B889 (2014) 36-45 | 10.1016/j.nuclphysb.2014.10.009 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Motivated by a hint in a CMS search for right-handed $W$-bosons in $eejj$
final states, we propose an experimental test of quark-mixing matrices in a
general left-right symmetric model, based on counting the numbers of $b$-tags
from right-handed $W$-boson hadronic decays. We find that, with our test,
differences between left- and right-handed quark-mixing matrices could be
detected at the LHC with $\sqrt{s}=14$ TeV. With an integrated luminosity of
about $20/\textrm{fb}$, our test is sensitive to right-handed quark-mixing
angles as small as about $30^\circ$ and with $3000/\textrm{fb}$, our test's
sensitivity improves to right-handed mixing angles as small as about
$7.5^\circ$. Our test's sensitivity might be further enhanced by tuning
$b$-tagging efficiency against purity.
| [
{
"created": "Thu, 28 Aug 2014 12:17:45 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Nov 2014 10:53:14 GMT",
"version": "v2"
}
] | 2016-09-19 | [
[
"Fowlie",
"Andrew",
""
],
[
"Marzola",
"Luca",
""
]
] | Motivated by a hint in a CMS search for right-handed $W$-bosons in $eejj$ final states, we propose an experimental test of quark-mixing matrices in a general left-right symmetric model, based on counting the numbers of $b$-tags from right-handed $W$-boson hadronic decays. We find that, with our test, differences between left- and right-handed quark-mixing matrices could be detected at the LHC with $\sqrt{s}=14$ TeV. With an integrated luminosity of about $20/\textrm{fb}$, our test is sensitive to right-handed quark-mixing angles as small as about $30^\circ$ and with $3000/\textrm{fb}$, our test's sensitivity improves to right-handed mixing angles as small as about $7.5^\circ$. Our test's sensitivity might be further enhanced by tuning $b$-tagging efficiency against purity. |
1912.05520 | Jean-Loup Tastet | Jean-Loup Tastet and Inar Timiryasov | Dirac vs. Majorana HNLs (and their oscillations) at SHiP | 37 pages, 13 figures | JHEP04(2020)005 | 10.1007/JHEP04(2020)005 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | SHiP is a proposed high-intensity beam dump experiment set to operate at the
CERN SPS. It is expected to have an unprecedented sensitivity to a variety of
models containing feebly interacting particles, such as Heavy Neutral Leptons
(HNLs). Two HNLs or more could successfully explain the observed neutrino
masses through the seesaw mechanism. If, in addition, they are
quasi-degenerate, they could be responsible for the baryon asymmetry of the
Universe. Depending on their mass splitting, HNLs can have very different
phenomenologies: they can behave as Majorana fermions -- with lepton number
violating (LNV) signatures, such as same-sign dilepton decays -- or as Dirac
fermions with only lepton number conserving (LNC) signatures. In this work, we
quantitatively demonstrate that LNV processes can be distinguished from LNC
ones at SHiP, using only the angular distribution of the HNL decay products.
Accounting for spin correlations in the simulation and using boosted decision
trees for discrimination, we show that SHiP will be able to distinguish
Majorana-like and Dirac-like HNLs in a significant fraction of the currently
unconstrained parameter space. If the mass splitting is of order $10^{-6}$ eV,
SHiP could even be capable of resolving HNL oscillations, thus providing a
direct measurement of the mass splitting. This analysis highlights the
potential of SHiP to not only search for feebly interacting particles, but also
perform model selection.
| [
{
"created": "Wed, 11 Dec 2019 18:44:53 GMT",
"version": "v1"
},
{
"created": "Mon, 6 Apr 2020 15:47:05 GMT",
"version": "v2"
}
] | 2020-04-07 | [
[
"Tastet",
"Jean-Loup",
""
],
[
"Timiryasov",
"Inar",
""
]
] | SHiP is a proposed high-intensity beam dump experiment set to operate at the CERN SPS. It is expected to have an unprecedented sensitivity to a variety of models containing feebly interacting particles, such as Heavy Neutral Leptons (HNLs). Two HNLs or more could successfully explain the observed neutrino masses through the seesaw mechanism. If, in addition, they are quasi-degenerate, they could be responsible for the baryon asymmetry of the Universe. Depending on their mass splitting, HNLs can have very different phenomenologies: they can behave as Majorana fermions -- with lepton number violating (LNV) signatures, such as same-sign dilepton decays -- or as Dirac fermions with only lepton number conserving (LNC) signatures. In this work, we quantitatively demonstrate that LNV processes can be distinguished from LNC ones at SHiP, using only the angular distribution of the HNL decay products. Accounting for spin correlations in the simulation and using boosted decision trees for discrimination, we show that SHiP will be able to distinguish Majorana-like and Dirac-like HNLs in a significant fraction of the currently unconstrained parameter space. If the mass splitting is of order $10^{-6}$ eV, SHiP could even be capable of resolving HNL oscillations, thus providing a direct measurement of the mass splitting. This analysis highlights the potential of SHiP to not only search for feebly interacting particles, but also perform model selection. |
2210.17477 | Matteo Becchetti | Simon Badger, Matteo Becchetti, Ekta Chaubey, Robin Marzucca | Two-loop master integrals for a planar topology contributing to $pp
\rightarrow t\bar{t}j$ | 31 pages, 47 figures, ancillary material attached to the submission.
Version v3 as published in JHEP | null | 10.1007/JHEP01(2023)156 | null | hep-ph hep-th | http://creativecommons.org/licenses/by/4.0/ | We consider the case of a two-loop five-point pentagon-box integral
configuration with one internal massive propagator that contributes to
top-quark pair production in association with a jet at hadron colliders. We
construct the system of differential equations for all the master integrals in
a canonical form where the analytic form is reconstructed from numerical
evaluations over finite fields. We find that the system can be represented as a
sum of d-logarithmic forms using an alphabet of 71 letters. Using high
precision boundary values obtained via the auxiliary mass flow method, a
numerical solution to the master integrals is provided using generalised power
series expansions.
| [
{
"created": "Mon, 31 Oct 2022 17:04:49 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Nov 2022 13:55:20 GMT",
"version": "v2"
},
{
"created": "Thu, 30 Mar 2023 08:12:54 GMT",
"version": "v3"
}
] | 2023-03-31 | [
[
"Badger",
"Simon",
""
],
[
"Becchetti",
"Matteo",
""
],
[
"Chaubey",
"Ekta",
""
],
[
"Marzucca",
"Robin",
""
]
] | We consider the case of a two-loop five-point pentagon-box integral configuration with one internal massive propagator that contributes to top-quark pair production in association with a jet at hadron colliders. We construct the system of differential equations for all the master integrals in a canonical form where the analytic form is reconstructed from numerical evaluations over finite fields. We find that the system can be represented as a sum of d-logarithmic forms using an alphabet of 71 letters. Using high precision boundary values obtained via the auxiliary mass flow method, a numerical solution to the master integrals is provided using generalised power series expansions. |
hep-ph/9804214 | null | J.R. Espinosa (CERN-TH), A. Riotto (CERN-TH) and G.G. Ross (Oxford) | D-term Inflation in Superstring Theories | 19 pages, LaTeX file | Nucl.Phys. B531 (1998) 461-477 | 10.1016/S0550-3213(98)00592-6 | CERN-TH/97-7 | hep-ph astro-ph hep-th | null | An inflationary stage dominated by a $D$-term avoids the slow-roll problem of
inflation in supergravity and may emerge in theories with a non-anomalous or
anomalous U(1) gauge symmetry. The most intriguing and commonly invoked
possibility is that the Fayet-Iliopoulos $D$-term triggering inflation is the
one emerging in superstring theories. We discuss the complications one has to
face when trying to build up a successful $D$-term inflationary scenario in
superstring models. In particular, we show that the ``vacuum shifting''
phenomenon of string theories is usually very efficient even in the early
Universe, thus preventing inflation from taking place. On the other hand, when
$D$-term inflation is free to occur, the presence of a plethora of fields and
several non-anomalous additional abelian symmetries in string theories may help
in reconciling the value of the Fayet-Iliopoulos $D$-term required by the COBE
normalization with the value predicted by string theories. We also show that in
superstring $D$-term inflation gravitinos are likely to pose no cosmological
problem.
| [
{
"created": "Thu, 2 Apr 1998 13:07:57 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Espinosa",
"J. R.",
"",
"CERN-TH"
],
[
"Riotto",
"A.",
"",
"CERN-TH"
],
[
"Ross",
"G. G.",
"",
"Oxford"
]
] | An inflationary stage dominated by a $D$-term avoids the slow-roll problem of inflation in supergravity and may emerge in theories with a non-anomalous or anomalous U(1) gauge symmetry. The most intriguing and commonly invoked possibility is that the Fayet-Iliopoulos $D$-term triggering inflation is the one emerging in superstring theories. We discuss the complications one has to face when trying to build up a successful $D$-term inflationary scenario in superstring models. In particular, we show that the ``vacuum shifting'' phenomenon of string theories is usually very efficient even in the early Universe, thus preventing inflation from taking place. On the other hand, when $D$-term inflation is free to occur, the presence of a plethora of fields and several non-anomalous additional abelian symmetries in string theories may help in reconciling the value of the Fayet-Iliopoulos $D$-term required by the COBE normalization with the value predicted by string theories. We also show that in superstring $D$-term inflation gravitinos are likely to pose no cosmological problem. |
2211.04490 | Rick Gupta | Rick S. Gupta, Joerg Jaeckel and Michael Spannowsky | Probing Poincar\'e Violation | 35 pages, 6 figures, | null | null | IPPP/22/42 | hep-ph hep-ex hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Time and space translation invariance, giving rise to energy and momentum
conservation, are not only amongst the most fundamental but also the most
generally accepted symmetry assumptions in physics. It is nevertheless prudent
to put such assumptions to experimental and observational tests. In this note,
we take the first step in this direction, specifying a simple periodic time
dependence that violates time translation invariance in QED, and setting
phenomenological constraints on it. In addition to observational and
experimental constraints on time varying couplings, we focus on probes of
violation of energy conservation such as spontaneous production of photon and
electron pairs and the $e \to e \gamma$ process. We discuss similarities and
differences to the discussion of time varying fundamental constants and to the
case of a light bosonic dark matter field that usually also causes oscillating
effects.
| [
{
"created": "Tue, 8 Nov 2022 19:00:13 GMT",
"version": "v1"
}
] | 2022-11-10 | [
[
"Gupta",
"Rick S.",
""
],
[
"Jaeckel",
"Joerg",
""
],
[
"Spannowsky",
"Michael",
""
]
] | Time and space translation invariance, giving rise to energy and momentum conservation, are not only amongst the most fundamental but also the most generally accepted symmetry assumptions in physics. It is nevertheless prudent to put such assumptions to experimental and observational tests. In this note, we take the first step in this direction, specifying a simple periodic time dependence that violates time translation invariance in QED, and setting phenomenological constraints on it. In addition to observational and experimental constraints on time varying couplings, we focus on probes of violation of energy conservation such as spontaneous production of photon and electron pairs and the $e \to e \gamma$ process. We discuss similarities and differences to the discussion of time varying fundamental constants and to the case of a light bosonic dark matter field that usually also causes oscillating effects. |
2312.06526 | Adrian Irles | E. Musumeci (1), A. Irles (1), R. Perez-Ramos (2,3), I. Corredoira
(4), E. Sarkisyan-Grinbaum (5,6), V. A. Mitsou (1,7) and M. A. Sanchis-Lozano
(1) ((1) Instituto de F\'isica Corpuscular, CSIC - University of Valencia,
Paterna (Valencia), Spain, (2) DRII-IPSA, Ivry-sur-Seine, France, (3)
Laboratoire de Physique Th \'eorique et Hautes Energies (LPTHE), Sorbonne
Universit\'e et CNRS, Paris Cedex, France, (4) Instituto Galego de F\'isica
de Altas Enerx\`ias (IGFAE, USC), Spain, (5) Experimental Physics Department,
CERN, Geneva, Switzerland, (6) Department of Physics, The University of Texas
at Arlington, Arlington, TX, USA, (7) Physics Division, School of Applied
Mathematical and Physical Sciences, National Technical University of Athens,
Athens, Greece) | Exploring hidden sectors with two-particle angular correlations at
future $e^{+}e^{-}$ colliders | To be submitted to PRL | null | null | IFIC/23-50 | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | Future $e^+e^-$ colliders are called to play a fundamental role in measuring
Standard Model (SM) parameters with unprecedented precision and the discovery
of physics beyond the SM (BSM). This study focus on a QCD-like Hidden Valley
(HV) scenario, with relatively light v-quarks ($\lesssim 100$ GeV), perturbing
the QCD partonic cascade and increasing azimuthal and (pseudo)rapidity
correlations of final-state SM hadrons. Using Pythia8 and detector fast
simulation tools we study $ridge$-$like$ structures arising in the two-particle
angular correlation function, including selection cuts and detector effects.
| [
{
"created": "Mon, 11 Dec 2023 17:04:04 GMT",
"version": "v1"
}
] | 2023-12-12 | [
[
"Musumeci",
"E.",
""
],
[
"Irles",
"A.",
""
],
[
"Perez-Ramos",
"R.",
""
],
[
"Corredoira",
"I.",
""
],
[
"Sarkisyan-Grinbaum",
"E.",
""
],
[
"Mitsou",
"V. A.",
""
],
[
"Sanchis-Lozano",
"M. A.",
""
]
] | Future $e^+e^-$ colliders are called to play a fundamental role in measuring Standard Model (SM) parameters with unprecedented precision and the discovery of physics beyond the SM (BSM). This study focus on a QCD-like Hidden Valley (HV) scenario, with relatively light v-quarks ($\lesssim 100$ GeV), perturbing the QCD partonic cascade and increasing azimuthal and (pseudo)rapidity correlations of final-state SM hadrons. Using Pythia8 and detector fast simulation tools we study $ridge$-$like$ structures arising in the two-particle angular correlation function, including selection cuts and detector effects. |
1111.6005 | Jan Hajer | S. Bobrovskyi, F. Br\"ummer, W. Buchmuller and J. Hajer | Searching for light higgsinos with b-jets and missing leptons | 16 pages, 3 figures, 8 tables | null | 10.1007/JHEP01(2012)122 | DESY 11-221 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A recently proposed class of supersymmetric models predicts rather light and
nearly mass-degenerate higgsinos, while the other superparticles are
significantly heavier. In this paper we study the early LHC phenomenology of a
benchmark model of this kind. If the squarks and gluinos, and in particular the
lighter stop, are still light enough to be within reach, then evidence for our
model can be found in hadronic SUSY searches. Moreover, with dedicated searches
it will be possible to distinguish the light higgsino model from generic SUSY
models with a bino LSP. Search channels with b-jets and with isolated leptons
play a crucial role for model discrimination.
| [
{
"created": "Fri, 25 Nov 2011 14:44:26 GMT",
"version": "v1"
}
] | 2015-06-03 | [
[
"Bobrovskyi",
"S.",
""
],
[
"Brümmer",
"F.",
""
],
[
"Buchmuller",
"W.",
""
],
[
"Hajer",
"J.",
""
]
] | A recently proposed class of supersymmetric models predicts rather light and nearly mass-degenerate higgsinos, while the other superparticles are significantly heavier. In this paper we study the early LHC phenomenology of a benchmark model of this kind. If the squarks and gluinos, and in particular the lighter stop, are still light enough to be within reach, then evidence for our model can be found in hadronic SUSY searches. Moreover, with dedicated searches it will be possible to distinguish the light higgsino model from generic SUSY models with a bino LSP. Search channels with b-jets and with isolated leptons play a crucial role for model discrimination. |
2303.14299 | Thomas A. Trainor | Thomas A. Trainor | Systematic analysis of (multi)strange hadron $p_t$ spectra from small
collision systems at the large hadron collider | 21 pages, 13 figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Small collision systems, e.g. $p$-$p$ and $p$-Pb collisions, comprise a
potential reference for more-central A-A collisions with regard to production
(or not) of a thermalized quark-gluon plasma (QGP). Small systems with low
particle densities should evolve according to simple QCD mechanisms including
projectile-nucleon dissociation and dijet production. But it is now claimed
that QGP may appear even in $p$-$p$ collisions based on apparent evidence for
radial flow from shape evolution of $p_t$ spectra and from variation of total
yields for strange and multistrange hadrons relative to statistical models. The
present study confronts such arguments with a detailed analysis of $p_t$
spectra for strange and multistrange hadrons from 5 TeV $p$-Pb collisions and
13 TeV $p$-$p$ collisions via a two-component model (TCM) of hadron production.
Based on previous analysis of lighter hadrons the TCM accurately predicts
spectra for Cascade and Omega hadrons. Significant results include multistrange
hadron spectra dominated by jet fragments, variation of strange-hadron
abundances exaggerated by certain plot formats and spectrum extrapolations, and
detailed relations between ensemble-mean $\bar p_t$ evolution with event charge
density and small shifts of jet fragment distributions on $p_t$. Within the
context of the TCM, $p$-$p$ and $p$-Pb collision systems with comparable jet
contributions are found to be equivalent within data uncertainties. Attribution
of certain data features to radial flow is falsified.
| [
{
"created": "Fri, 24 Mar 2023 23:23:19 GMT",
"version": "v1"
}
] | 2023-03-28 | [
[
"Trainor",
"Thomas A.",
""
]
] | Small collision systems, e.g. $p$-$p$ and $p$-Pb collisions, comprise a potential reference for more-central A-A collisions with regard to production (or not) of a thermalized quark-gluon plasma (QGP). Small systems with low particle densities should evolve according to simple QCD mechanisms including projectile-nucleon dissociation and dijet production. But it is now claimed that QGP may appear even in $p$-$p$ collisions based on apparent evidence for radial flow from shape evolution of $p_t$ spectra and from variation of total yields for strange and multistrange hadrons relative to statistical models. The present study confronts such arguments with a detailed analysis of $p_t$ spectra for strange and multistrange hadrons from 5 TeV $p$-Pb collisions and 13 TeV $p$-$p$ collisions via a two-component model (TCM) of hadron production. Based on previous analysis of lighter hadrons the TCM accurately predicts spectra for Cascade and Omega hadrons. Significant results include multistrange hadron spectra dominated by jet fragments, variation of strange-hadron abundances exaggerated by certain plot formats and spectrum extrapolations, and detailed relations between ensemble-mean $\bar p_t$ evolution with event charge density and small shifts of jet fragment distributions on $p_t$. Within the context of the TCM, $p$-$p$ and $p$-Pb collision systems with comparable jet contributions are found to be equivalent within data uncertainties. Attribution of certain data features to radial flow is falsified. |
2204.13134 | Jonathan Kriewald | J. Kriewald, J. Orloff, E. Pinsard, A. M. Teixeira | Prospects for a flavour violating $Z^\prime$ explanation of $\Delta
a_{\mu,e}$ | 36 pages, 15 figures, v3: minor changes, few clarifications added,
results and conclusions unchanged, matches version published in EPJC | null | 10.1140/epjc/s10052-022-10776-1 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The apparent tensions emerging from the comparison of experimental data of
the anomalous magnetic moments of the muon and electron to the Standard Model
predictions ($\Delta a_{\mu,e}$) could be interpreted as a potential signal of
New Physics. Models encompassing a light vector boson have been known to offer
a satisfactory explanation to $\Delta a_{\mu}$, albeit subject to stringent
experimental constraints. Here we explore a minimal extension of the Standard
Model via a leptophilic vector boson $Z^\prime$, under the hypothesis of
strictly flavour-violating couplings of the latter to leptons. The most
constraining observables to this ad-hoc construction emerge from lepton flavour
universality violation (in $Z$ and $\tau$ decays) and from rare charged lepton
flavour violating transitions. Once these are accommodated, one can saturate
the tensions in $\Delta a_{\mu}$, but $\Delta a_{e}$ is predicted to be
Standard Model-like. We infer prospects for several observables, including
leptonic $Z$ decays and several charged lepton flavour violating processes. We
also discuss potential signatures of the considered $Z^\prime$ at a future muon
collider, emphasising the role of the $\mu^+\mu^- \to\tau^+\tau^- $
forward-backward asymmetry as a key probe of the model.
| [
{
"created": "Wed, 27 Apr 2022 18:04:26 GMT",
"version": "v1"
},
{
"created": "Wed, 6 Jul 2022 16:06:33 GMT",
"version": "v2"
},
{
"created": "Mon, 17 Oct 2022 10:29:54 GMT",
"version": "v3"
}
] | 2022-10-18 | [
[
"Kriewald",
"J.",
""
],
[
"Orloff",
"J.",
""
],
[
"Pinsard",
"E.",
""
],
[
"Teixeira",
"A. M.",
""
]
] | The apparent tensions emerging from the comparison of experimental data of the anomalous magnetic moments of the muon and electron to the Standard Model predictions ($\Delta a_{\mu,e}$) could be interpreted as a potential signal of New Physics. Models encompassing a light vector boson have been known to offer a satisfactory explanation to $\Delta a_{\mu}$, albeit subject to stringent experimental constraints. Here we explore a minimal extension of the Standard Model via a leptophilic vector boson $Z^\prime$, under the hypothesis of strictly flavour-violating couplings of the latter to leptons. The most constraining observables to this ad-hoc construction emerge from lepton flavour universality violation (in $Z$ and $\tau$ decays) and from rare charged lepton flavour violating transitions. Once these are accommodated, one can saturate the tensions in $\Delta a_{\mu}$, but $\Delta a_{e}$ is predicted to be Standard Model-like. We infer prospects for several observables, including leptonic $Z$ decays and several charged lepton flavour violating processes. We also discuss potential signatures of the considered $Z^\prime$ at a future muon collider, emphasising the role of the $\mu^+\mu^- \to\tau^+\tau^- $ forward-backward asymmetry as a key probe of the model. |
2302.06623 | Maximilian Stahlhofen | Piotr Pietrulewicz and Maximilian Stahlhofen | Two-loop bottom mass effects on the Higgs transverse momentum spectrum
in top-induced gluon fusion | 38 pages, 6 figures; v2: journal version | JHEP05(2023)175 | 10.1007/JHEP05(2023)175 | FR-PHENO-2023-03 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute bottom mass ($m_b$) corrections to the transverse momentum ($q_T$)
spectrum of Higgs bosons produced by gluon fusion in the regime $q_T \sim m_b
\ll m_H$ at leading power in $m_b/m_H$ and $q_T/m_H$, where the gluons couple
to the Higgs via a top loop. To this end we calculate the quark mass dependence
of the transverse momentum dependent gluon beam functions (aka gluon TMDPDFs)
at two loops in the framework of SCET. These functions represent the collinear
matrix elements in the factorized gluon-fusion cross section for small $q_T$.
We discuss in detail technical subtleties regarding rapidity regulators and
zero-bin subtractions in the calculation of the virtual corrections present for
massive quarks. Combined with the known soft function for $m_b \neq 0$ our
results allow to determine the resummed Higgs $q_T$ distribution in the
top-induced gluon fusion channel at NNLL$^\prime$ (and eventually N$^3$LL) with
full dependence on $m_b/q_T$. We perform a first phenomenological analysis at
fixed order, where the new corrections to the massless approximation lead to
percent-level effects in the peak region of the Higgs $q_T$ spectrum. Upon
resummation they may thus be relevant for state-of-the-art precision
predictions for the LHC.
| [
{
"created": "Mon, 13 Feb 2023 19:00:00 GMT",
"version": "v1"
},
{
"created": "Wed, 24 May 2023 21:26:19 GMT",
"version": "v2"
}
] | 2023-05-26 | [
[
"Pietrulewicz",
"Piotr",
""
],
[
"Stahlhofen",
"Maximilian",
""
]
] | We compute bottom mass ($m_b$) corrections to the transverse momentum ($q_T$) spectrum of Higgs bosons produced by gluon fusion in the regime $q_T \sim m_b \ll m_H$ at leading power in $m_b/m_H$ and $q_T/m_H$, where the gluons couple to the Higgs via a top loop. To this end we calculate the quark mass dependence of the transverse momentum dependent gluon beam functions (aka gluon TMDPDFs) at two loops in the framework of SCET. These functions represent the collinear matrix elements in the factorized gluon-fusion cross section for small $q_T$. We discuss in detail technical subtleties regarding rapidity regulators and zero-bin subtractions in the calculation of the virtual corrections present for massive quarks. Combined with the known soft function for $m_b \neq 0$ our results allow to determine the resummed Higgs $q_T$ distribution in the top-induced gluon fusion channel at NNLL$^\prime$ (and eventually N$^3$LL) with full dependence on $m_b/q_T$. We perform a first phenomenological analysis at fixed order, where the new corrections to the massless approximation lead to percent-level effects in the peak region of the Higgs $q_T$ spectrum. Upon resummation they may thus be relevant for state-of-the-art precision predictions for the LHC. |
hep-ph/0605195 | Qiuyu Liu | B.L. Chen (1), H.L. Ge (1), C. Giunti (2), Q.Y. Liu (1) ((1) CUST,
Hefei, (2) INFN, Turin & Turin U.) | Testing the Stability of the Solar Neutrino LMA Solution with a Bayesian
Analysis | 13 pages, 15 eps figures | Mod.Phys.Lett. A21 (2006) 2269-2282 | 10.1142/S0217732306021608 | null | hep-ph | null | We analyze with the Bayesian method the solar and KamLAND neutrino data in
terms of neutrino oscillations. We show that Bayesian credible regions with a
flat prior in the tan^2(theta12)--(Delta m^2)_21 plane strongly support the LMA
solution, in agreement with the usual chi-square analysis. Other reasonable
priors are considered in order to test the stability of the LMA solution. We
show that priors which favor small or large values of the mixing angle lead to
minor changes of the allowed LMA region, affecting mainly its large
tan^2(theta12) part.
| [
{
"created": "Wed, 17 May 2006 09:55:59 GMT",
"version": "v1"
}
] | 2009-11-11 | [
[
"Chen",
"B. L.",
""
],
[
"Ge",
"H. L.",
""
],
[
"Giunti",
"C.",
""
],
[
"Liu",
"Q. Y.",
""
]
] | We analyze with the Bayesian method the solar and KamLAND neutrino data in terms of neutrino oscillations. We show that Bayesian credible regions with a flat prior in the tan^2(theta12)--(Delta m^2)_21 plane strongly support the LMA solution, in agreement with the usual chi-square analysis. Other reasonable priors are considered in order to test the stability of the LMA solution. We show that priors which favor small or large values of the mixing angle lead to minor changes of the allowed LMA region, affecting mainly its large tan^2(theta12) part. |
1710.05523 | Ying Zhang | Ying Zhang | An open window to neutrino mass hierarchy at maximal Dirac CP violation | 6 pages, 2 figures and 1 table | null | null | null | hep-ph | http://creativecommons.org/licenses/by-nc-sa/4.0/ | Non-zero leptonic CP phases in the neutrino sector are clear evidence for
physics beyond the Standard Model and have many implications in particle
physics and cosmology. Some clues to maximal Dirac CP violation
$\delta_{CP}=3\pi/2$ are reviewed. An approach to connect the Dirac CP
violation phase and the neutrino mass hierarchy in terms of the measurement of
CP asymmetry is proposed. Under appropriate requirements for baseline distance
and beam energy, the problem of neutrino mass hierarchy can be revealed at
maximal Dirac CP violation. General allowed parameter spaces are investigated,
within which the two unknown neutrino issues, mass hierarchy and Dirac CP
violation, can be solved simultaneously. The abilities of addressing the mass
hierarchy of current long baseline neutrino experiments are also discussed.
| [
{
"created": "Mon, 16 Oct 2017 06:01:20 GMT",
"version": "v1"
}
] | 2017-10-17 | [
[
"Zhang",
"Ying",
""
]
] | Non-zero leptonic CP phases in the neutrino sector are clear evidence for physics beyond the Standard Model and have many implications in particle physics and cosmology. Some clues to maximal Dirac CP violation $\delta_{CP}=3\pi/2$ are reviewed. An approach to connect the Dirac CP violation phase and the neutrino mass hierarchy in terms of the measurement of CP asymmetry is proposed. Under appropriate requirements for baseline distance and beam energy, the problem of neutrino mass hierarchy can be revealed at maximal Dirac CP violation. General allowed parameter spaces are investigated, within which the two unknown neutrino issues, mass hierarchy and Dirac CP violation, can be solved simultaneously. The abilities of addressing the mass hierarchy of current long baseline neutrino experiments are also discussed. |
hep-ph/9209262 | null | H.Y. Cheng, C.Y. Cheung, G.L. Lin, Y.C. Lin, T.M. Yan, and H.L. Yu | Chiral Lagrangians for Radiative Decays of Heavy Hadrons | 30 pages (one figure, available on request), CLNS 92/1158 and
IP-ASTP-13-92 | Phys.Rev. D47 (1993) 1030-1042 | 10.1103/PhysRevD.47.1030 | null | hep-ph | null | The radiative decays of heavy mesons and heavy baryons are studied in a
formalism which incorporates both the heavy quark symmetry and the chiral
symmetry. The chiral Lagrangians for the electromagnetic interactions of heavy
hadrons consist of two pieces: one from gauging electromagnetically the
strong-interaction chiral Lagrangian, and the other from the anomalous magnetic
moment interactions of the heavy baryons and mesons. Due to the heavy quark
spin symmetry, the latter contains only one independent coupling constant in
the meson sector and two in the baryon sector. These coupling constants only
depend on the light quarks and can be calculated in the nonrelativistic quark
model. However, the charm quark is not heavy enough and the contribution from
its magnetic moment must be included. Applications to the radiative decays
$D^\ast \rightarrow D \gamma~,~B^\ast \rightarrow B \gamma~,~ \Xi^\prime_c
\rightarrow \Xi_c \gamma~, \Sigma_c \rightarrow \Lambda_c \gamma$ and $\Sigma_c
\rightarrow \Lambda_c \pi \gamma$ are given. Together with our previous results
on the strong decay rates of $D^\ast \rightarrow D \pi$ and $\Sigma_c
\rightarrow \Lambda_c \pi$, predictions are obtained for the total widths and
branching ratios of $D^\ast$ and $\Sigma_c$. The decays $\Sigma^+_c \rightarrow
\Lambda^+_c \pi^0 \gamma $ and $\Sigma^0_c \rightarrow \Lambda^+_c \pi^- \gamma
$ are discussed to illustrate the important roles played by both the heavy
quark symmetry and the chiral symmetry.
| [
{
"created": "Mon, 21 Sep 1992 19:04:00 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Cheng",
"H. Y.",
""
],
[
"Cheung",
"C. Y.",
""
],
[
"Lin",
"G. L.",
""
],
[
"Lin",
"Y. C.",
""
],
[
"Yan",
"T. M.",
""
],
[
"Yu",
"H. L.",
""
]
] | The radiative decays of heavy mesons and heavy baryons are studied in a formalism which incorporates both the heavy quark symmetry and the chiral symmetry. The chiral Lagrangians for the electromagnetic interactions of heavy hadrons consist of two pieces: one from gauging electromagnetically the strong-interaction chiral Lagrangian, and the other from the anomalous magnetic moment interactions of the heavy baryons and mesons. Due to the heavy quark spin symmetry, the latter contains only one independent coupling constant in the meson sector and two in the baryon sector. These coupling constants only depend on the light quarks and can be calculated in the nonrelativistic quark model. However, the charm quark is not heavy enough and the contribution from its magnetic moment must be included. Applications to the radiative decays $D^\ast \rightarrow D \gamma~,~B^\ast \rightarrow B \gamma~,~ \Xi^\prime_c \rightarrow \Xi_c \gamma~, \Sigma_c \rightarrow \Lambda_c \gamma$ and $\Sigma_c \rightarrow \Lambda_c \pi \gamma$ are given. Together with our previous results on the strong decay rates of $D^\ast \rightarrow D \pi$ and $\Sigma_c \rightarrow \Lambda_c \pi$, predictions are obtained for the total widths and branching ratios of $D^\ast$ and $\Sigma_c$. The decays $\Sigma^+_c \rightarrow \Lambda^+_c \pi^0 \gamma $ and $\Sigma^0_c \rightarrow \Lambda^+_c \pi^- \gamma $ are discussed to illustrate the important roles played by both the heavy quark symmetry and the chiral symmetry. |
hep-ph/0112058 | Sean Fleming | Sean Fleming (Carnegie Mellon University) | Production & Decay of Quarkonium | Invited talk: 9th International Symposium on Heavy Flavor Physics | AIP Conf.Proc. 618 (2002) 405-414 | 10.1063/1.1478859 | null | hep-ph | null | In this talk I review NRQCD predictions for the production of charmonium at
the Tevatron. After a quick presentation of the NRQCD factorization formalism
for production and decay I review some old results and discuss how they compare
to recent data. Following this I discuss some recent work done with Adam
Leibovich and Ira Rothstein.
| [
{
"created": "Tue, 4 Dec 2001 19:18:26 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Fleming",
"Sean",
"",
"Carnegie Mellon University"
]
] | In this talk I review NRQCD predictions for the production of charmonium at the Tevatron. After a quick presentation of the NRQCD factorization formalism for production and decay I review some old results and discuss how they compare to recent data. Following this I discuss some recent work done with Adam Leibovich and Ira Rothstein. |
hep-ph/9305207 | Sergei Khlebnikov | S. Yu. Khlebnikov | Disoriented chiral condensate in (1+1) Lorentz-invariant geometry | 9 pages, LATEX, UCLA/93/TEP/10 | Mod.Phys.Lett. A8 (1993) 1901-1908 | 10.1142/S0217732393001628 | null | hep-ph | null | We consider isospin correlations of pions produced in a relativistic nuclear
collision, using an effective theory of the chiral order parameter. Our theory
has (1+1) Lorentz invariance as appropriate for the central rapidity region. We
argue that in certain regions of space correlations of the chiral order
parameter are described by the fixed point of the (1+1) WZNW model. The
corresponding anomalous dimension determines scaling of the probability to
observe a correlated cluster of pions with the size of this cluster in
rapidity. Though the maximal size of clusters for which this scaling is
applicable is cut off by pion mass, such clusters can still include
sufficiently many particles to make the scaling observable.
| [
{
"created": "Tue, 4 May 1993 00:41:00 GMT",
"version": "v1"
}
] | 2015-06-25 | [
[
"Khlebnikov",
"S. Yu.",
""
]
] | We consider isospin correlations of pions produced in a relativistic nuclear collision, using an effective theory of the chiral order parameter. Our theory has (1+1) Lorentz invariance as appropriate for the central rapidity region. We argue that in certain regions of space correlations of the chiral order parameter are described by the fixed point of the (1+1) WZNW model. The corresponding anomalous dimension determines scaling of the probability to observe a correlated cluster of pions with the size of this cluster in rapidity. Though the maximal size of clusters for which this scaling is applicable is cut off by pion mass, such clusters can still include sufficiently many particles to make the scaling observable. |
2311.01353 | Evgeny Zhemchugov | E. V. Zhemchugov, S. I. Godunov, E. K. Karkaryan, V. A. Novikov, A. N.
Rozanov, M. I. Vysotsky | libepa -- a C++/Python library for calculations of cross sections of
ultraperipheral collisions | 25 pages, 6 figures, 1 table. See the arXiv archive for supplementary
materials (code) | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The library provides a set of C++/Python functions for computing cross
sections of ultraperipheral collisions of high energy particles under the
equivalent photons approximation. Cross sections are represented through
multiple integrals over the phase space. The integrals are calculated through
recurrent application of algorithms for one dimensional integration. The paper
contains an introduction to the theory of ultraperipheral collisions, discusses
the library approach and provides a few examples of calculations.
| [
{
"created": "Thu, 2 Nov 2023 16:01:15 GMT",
"version": "v1"
}
] | 2023-11-03 | [
[
"Zhemchugov",
"E. V.",
""
],
[
"Godunov",
"S. I.",
""
],
[
"Karkaryan",
"E. K.",
""
],
[
"Novikov",
"V. A.",
""
],
[
"Rozanov",
"A. N.",
""
],
[
"Vysotsky",
"M. I.",
""
]
] | The library provides a set of C++/Python functions for computing cross sections of ultraperipheral collisions of high energy particles under the equivalent photons approximation. Cross sections are represented through multiple integrals over the phase space. The integrals are calculated through recurrent application of algorithms for one dimensional integration. The paper contains an introduction to the theory of ultraperipheral collisions, discusses the library approach and provides a few examples of calculations. |
0712.4210 | Andre Sopczak | A. Sopczak, A. Freitas, C. Milstene, M. Schmitt | Precision Measurements of the Stop Quark Mass at the ILC | 4 pages, 4 figures, presented at SUSY'07, Karlsruhe | null | null | null | hep-ph | null | Most supersymmetric models predict new particles within the reach of the next
generation of colliders. For an understanding of the model structure and the
mechanism(s) of electroweak symmetry breaking, it is important to know the
masses of the new particles precisely. The measurement of the mass of the
scalar partner of the top quark (stop) at an e+e- collider is studied. A
relatively light stop is motivated by attempts to explain electroweak
baryogenesis and can play an important role in dark matter annihilation. A
method is presented which makes use of cross-section measurements near the
pair-production threshold as well as at higher center-of-mass energies. It is
shown that this method does not only increase the statistical precision, but
also reduces the influence of systematic uncertainties, which can be important.
Numerical results are presented, based on a realistic event simulation, for two
signal selection strategies: using conventional selection cuts, and using an
Iterative Discriminant Analysis (IDA). While the analysis of stops is
particularly challenging due to the possibility of stop hadronization and
fragmentation, the general procedure could be applied to many precision mass
measurements.
| [
{
"created": "Thu, 27 Dec 2007 10:30:15 GMT",
"version": "v1"
}
] | 2007-12-28 | [
[
"Sopczak",
"A.",
""
],
[
"Freitas",
"A.",
""
],
[
"Milstene",
"C.",
""
],
[
"Schmitt",
"M.",
""
]
] | Most supersymmetric models predict new particles within the reach of the next generation of colliders. For an understanding of the model structure and the mechanism(s) of electroweak symmetry breaking, it is important to know the masses of the new particles precisely. The measurement of the mass of the scalar partner of the top quark (stop) at an e+e- collider is studied. A relatively light stop is motivated by attempts to explain electroweak baryogenesis and can play an important role in dark matter annihilation. A method is presented which makes use of cross-section measurements near the pair-production threshold as well as at higher center-of-mass energies. It is shown that this method does not only increase the statistical precision, but also reduces the influence of systematic uncertainties, which can be important. Numerical results are presented, based on a realistic event simulation, for two signal selection strategies: using conventional selection cuts, and using an Iterative Discriminant Analysis (IDA). While the analysis of stops is particularly challenging due to the possibility of stop hadronization and fragmentation, the general procedure could be applied to many precision mass measurements. |
0706.3909 | Olga Mena Requejo | Olga Mena (INFN, Rome; Rome U.), Sergio Palomares-Ruiz and Silvia
Pascoli (Durham U., IPPP) | Reconstructing WIMP properties with neutrino detectors | 4 pp, 2 figs; revised version accepted for publication with further
discussions and references | Phys.Lett.B664:92-96,2008 | 10.1016/j.physletb.2008.04.059 | IPPP/07/34, DCPT/07/68 | hep-ph astro-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | If the dark matter of the Universe is constituted by weakly interacting
massive particles (WIMP), they would accumulate in the core of astrophysical
objects as the Sun and annihilate into particles of the Standard Model.
High-energy neutrinos would be produced in the annihilations, both directly and
via the subsequent decay of leptons, quarks and bosons. While Cherenkov
neutrino detectors/telescopes can only count the number of neutrinos above some
threshold energy, we study how, by exploiting their energy resolution, large
magnetized iron calorimeter and, possibly, liquid argon and totally active
scintillator detectors, planned for future long baseline neutrino experiments,
have the capability of reconstructing the neutrino spectrum and might provide
information on the dark matter properties. In particular, for a given value of
the WIMP mass, we show that a future iron calorimeter could break the
degeneracy between the WIMP-proton cross section and the annihilation branching
ratios, present for Cherenkov detectors, and constrain their values with good
accuracy.
| [
{
"created": "Wed, 27 Jun 2007 18:48:18 GMT",
"version": "v1"
},
{
"created": "Thu, 26 Jun 2008 17:18:45 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Mena",
"Olga",
"",
"INFN, Rome; Rome U."
],
[
"Palomares-Ruiz",
"Sergio",
"",
"Durham U., IPPP"
],
[
"Pascoli",
"Silvia",
"",
"Durham U., IPPP"
]
] | If the dark matter of the Universe is constituted by weakly interacting massive particles (WIMP), they would accumulate in the core of astrophysical objects as the Sun and annihilate into particles of the Standard Model. High-energy neutrinos would be produced in the annihilations, both directly and via the subsequent decay of leptons, quarks and bosons. While Cherenkov neutrino detectors/telescopes can only count the number of neutrinos above some threshold energy, we study how, by exploiting their energy resolution, large magnetized iron calorimeter and, possibly, liquid argon and totally active scintillator detectors, planned for future long baseline neutrino experiments, have the capability of reconstructing the neutrino spectrum and might provide information on the dark matter properties. In particular, for a given value of the WIMP mass, we show that a future iron calorimeter could break the degeneracy between the WIMP-proton cross section and the annihilation branching ratios, present for Cherenkov detectors, and constrain their values with good accuracy. |
hep-ph/9503302 | Xerxes Tata | Xerxes Tata | Recent Developments in supersymmetry Search Strategies | Talk presented at the 11th Dep't of Atomic Energy Symposium,
Visvabharati University, Santiniketan, India. 19 pages. World_sci.sty
attached after Latex file; Figures may be obtained by regular mail or fax
from the Author. | null | null | UH-511-820-95 | hep-ph | null | After a quick review of the framework for phenomenological analyses of
supersymmetry, we summarize current limits on supersymmetric particle masses
and discuss strategies for their searches at the Fermilab Tevatron and the LHC.
We also discuss the sense in which such searches as well as those that may be
carried out at LEP complement one another. Finally, we touch upon the prospects
for more ambitious measurements such as those of sparticle masses and
couplings. Such measurements could (a) help pin down model parameters, (b)
perhaps, serve to test our ideas of physics at very high energy, and (c)
provide the most direct test of supersymmetry.
| [
{
"created": "Sat, 11 Mar 1995 22:10:53 GMT",
"version": "v1"
}
] | 2016-09-01 | [
[
"Tata",
"Xerxes",
""
]
] | After a quick review of the framework for phenomenological analyses of supersymmetry, we summarize current limits on supersymmetric particle masses and discuss strategies for their searches at the Fermilab Tevatron and the LHC. We also discuss the sense in which such searches as well as those that may be carried out at LEP complement one another. Finally, we touch upon the prospects for more ambitious measurements such as those of sparticle masses and couplings. Such measurements could (a) help pin down model parameters, (b) perhaps, serve to test our ideas of physics at very high energy, and (c) provide the most direct test of supersymmetry. |
1503.00009 | Hou Keong Lou | Timothy Cohen, Mariangela Lisanti, Hou Keong Lou | Semi-visible Jets: Dark Matter Undercover at the LHC | 5 pages, 3 figures. v3: Supplementary material and references added.
Model changed from scalar to fermionic dark quarks and figures updated
accordingly. Conclusions unchanged | Phys. Rev. Lett. 115, 171804 (2015) | 10.1103/PhysRevLett.115.171804 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The dark matter may be a composite particle that is accessible via a weakly
coupled portal. If these hidden-sector states are produced at the Large Hadron
Collider (LHC), they would undergo a QCD-like shower. This would result in a
spray of stable invisible dark matter along with unstable states that decay
back to the Standard Model. Such "semi-visible" jets arise, for example, when
their production and decay are driven by a leptophobic $Z'$ resonance; the
resulting signature is characterized by significant missing energy aligned
along the direction of one of the jets. These events are vetoed by the current
suite of searches employed by the LHC, resulting in low acceptance. This Letter
will demonstrate that the transverse mass---computed using the final-state jets
and the missing energy---provides a powerful discriminator between the signal
and the QCD background. Assuming that the $Z'$ couples to the Standard Model
quarks with the same strength as the $Z^0$, the proposed search can discover
(exclude) $Z'$ masses up to 2.5 TeV (3.5 TeV) with 100 fb$^{-1}$ of 14 TeV data
at the LHC.
| [
{
"created": "Fri, 27 Feb 2015 21:01:27 GMT",
"version": "v1"
},
{
"created": "Fri, 27 Mar 2015 19:02:31 GMT",
"version": "v2"
},
{
"created": "Tue, 14 Jul 2015 20:23:59 GMT",
"version": "v3"
}
] | 2015-10-28 | [
[
"Cohen",
"Timothy",
""
],
[
"Lisanti",
"Mariangela",
""
],
[
"Lou",
"Hou Keong",
""
]
] | The dark matter may be a composite particle that is accessible via a weakly coupled portal. If these hidden-sector states are produced at the Large Hadron Collider (LHC), they would undergo a QCD-like shower. This would result in a spray of stable invisible dark matter along with unstable states that decay back to the Standard Model. Such "semi-visible" jets arise, for example, when their production and decay are driven by a leptophobic $Z'$ resonance; the resulting signature is characterized by significant missing energy aligned along the direction of one of the jets. These events are vetoed by the current suite of searches employed by the LHC, resulting in low acceptance. This Letter will demonstrate that the transverse mass---computed using the final-state jets and the missing energy---provides a powerful discriminator between the signal and the QCD background. Assuming that the $Z'$ couples to the Standard Model quarks with the same strength as the $Z^0$, the proposed search can discover (exclude) $Z'$ masses up to 2.5 TeV (3.5 TeV) with 100 fb$^{-1}$ of 14 TeV data at the LHC. |
hep-ph/0512055 | Shouhua Zhu | Shou-hua Zhu | Detecting an invisible Higgs boson at Fermilab Tevatron and CERN LHC | 4 Revtex pages including 2 figures | Eur.Phys.J.C47:833-837,2006 | 10.1140/epjc/s2006-02607-6 | null | hep-ph hep-ex | null | In this paper, we study the observability of an invisible Higgs boson at
Fermilab Tevatron and CERN LHC through the production channel $ q \bar{q} \to Z
H \to \ell^+\ell^-+ \ptmiss $, where $\ptmiss$ is reconstructed from the
$\ell^+\ell^-$ with $\ell=e$ or $\mu$. A new strategy is proposed to eliminate
the largest irreducible background, namely $ q \bar{q} \to Z(\to \ell^+\ell^-)
Z(\to \nu \bar\nu)$. This strategy utilizes the precise measurements of $ q
\bar{q} \to Z(\to \ell^+\ell^-) Z(\to \ell^+\ell^-)$. For $m_H=120$ GeV and
with luminosity $30 fb^{-1}$ at Tevatron, a $5\sigma$ observation of the
invisible Higgs boson is possible. For $m_H=114 \sim 140$ GeV with only $10
fb^{-1}$ luminosity at LHC, a discovery signal over $5\sigma$ can be achieved.
| [
{
"created": "Mon, 5 Dec 2005 02:30:31 GMT",
"version": "v1"
},
{
"created": "Wed, 14 Dec 2005 03:21:24 GMT",
"version": "v2"
},
{
"created": "Fri, 27 Jan 2006 08:30:18 GMT",
"version": "v3"
}
] | 2009-01-07 | [
[
"Zhu",
"Shou-hua",
""
]
] | In this paper, we study the observability of an invisible Higgs boson at Fermilab Tevatron and CERN LHC through the production channel $ q \bar{q} \to Z H \to \ell^+\ell^-+ \ptmiss $, where $\ptmiss$ is reconstructed from the $\ell^+\ell^-$ with $\ell=e$ or $\mu$. A new strategy is proposed to eliminate the largest irreducible background, namely $ q \bar{q} \to Z(\to \ell^+\ell^-) Z(\to \nu \bar\nu)$. This strategy utilizes the precise measurements of $ q \bar{q} \to Z(\to \ell^+\ell^-) Z(\to \ell^+\ell^-)$. For $m_H=120$ GeV and with luminosity $30 fb^{-1}$ at Tevatron, a $5\sigma$ observation of the invisible Higgs boson is possible. For $m_H=114 \sim 140$ GeV with only $10 fb^{-1}$ luminosity at LHC, a discovery signal over $5\sigma$ can be achieved. |
0709.0065 | Alejandro Cabo | Alejandro Cabo Montes de Oca | Renormalized Wick expansion for a modified PQCD | 13 pages, one figure | Eur.Phys.J.C55:85-93,2008 | 10.1140/epjc/s10052-008-0565-y | ICTP Preprint IC/2007/083 August (2007) | hep-ph | null | The renormalization scheme for the Wick expansion of a modified version of
the perturbative QCD introduced in previous works is discussed. Massless QCD is
considered, by implementing the usual multiplicative scaling of the gluon and
quark wave functions and vertices. However, also massive quark and gluon
counter-terms are allowed in this mass less theory since the condensates are
expected to generate masses. A natural set of expansion parameters of the
physical quantities is introduced: the coupling itself and to masses $m_q$ and
$m_g$ associated to quarks and gluons respectively. This procedure allows to
implement a dimensional transmutation effect through these new mass scales. A
general expression for the new generating functional in terms of the mass
parameters $m_q$ and $m_g$ is obtained in terms of integrals over arbitrary but
constant gluon or quark fields in each case. Further, the one loop potential,
is evaluated in more detail in the case when only the quark condensate is
retained. This lowest order result again indicates the dynamical generation of
quark condensates in the vacuum.
| [
{
"created": "Sat, 1 Sep 2007 14:21:12 GMT",
"version": "v1"
}
] | 2014-11-18 | [
[
"de Oca",
"Alejandro Cabo Montes",
""
]
] | The renormalization scheme for the Wick expansion of a modified version of the perturbative QCD introduced in previous works is discussed. Massless QCD is considered, by implementing the usual multiplicative scaling of the gluon and quark wave functions and vertices. However, also massive quark and gluon counter-terms are allowed in this mass less theory since the condensates are expected to generate masses. A natural set of expansion parameters of the physical quantities is introduced: the coupling itself and to masses $m_q$ and $m_g$ associated to quarks and gluons respectively. This procedure allows to implement a dimensional transmutation effect through these new mass scales. A general expression for the new generating functional in terms of the mass parameters $m_q$ and $m_g$ is obtained in terms of integrals over arbitrary but constant gluon or quark fields in each case. Further, the one loop potential, is evaluated in more detail in the case when only the quark condensate is retained. This lowest order result again indicates the dynamical generation of quark condensates in the vacuum. |
hep-ph/9705370 | D. P. Roy | D.P. Roy | New Physics from HERA? | LaTeX file (7 pages), 3 figures available on request, Made minor
stylistic changes and added a reference | null | null | TIFR/TH/97-24 | hep-ph | null | The H1 and ZEUS experiments at the HERA $e^\pm p$ collider at Hamburg have
recently reported some anomalous hard-scattering events, which could be
indicative of new physics beyond the standard model. I have tried to discuss in
a nonspecialist language the significance of this result for particle physics
along with its interpretation in terms of the currently popular extensions of
the standard model.
| [
{
"created": "Wed, 21 May 1997 11:26:13 GMT",
"version": "v1"
},
{
"created": "Tue, 27 May 1997 11:52:37 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Roy",
"D. P.",
""
]
] | The H1 and ZEUS experiments at the HERA $e^\pm p$ collider at Hamburg have recently reported some anomalous hard-scattering events, which could be indicative of new physics beyond the standard model. I have tried to discuss in a nonspecialist language the significance of this result for particle physics along with its interpretation in terms of the currently popular extensions of the standard model. |
hep-ph/0409295 | Makoto Oka | Makoto Oka | QCD Sum Rules of Pentaquarks | Invited talk presented at the PENTAQUARK04 at SPring-8 in July 20-23,
2004 | null | 10.1142/9789812701855_0049 | null | hep-ph | null | QCD sum rule is applied to the pentaquark spectroscopy. It is concluded that
no positive parity state is seen in low energy region, while there may exist
negative parity states at around 1.5 GeV. Choice of interpolating local
operators and relation to the lattice calculations are discussed.
| [
{
"created": "Sat, 25 Sep 2004 12:06:33 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Oka",
"Makoto",
""
]
] | QCD sum rule is applied to the pentaquark spectroscopy. It is concluded that no positive parity state is seen in low energy region, while there may exist negative parity states at around 1.5 GeV. Choice of interpolating local operators and relation to the lattice calculations are discussed. |
hep-ph/9907472 | Andreas Vogt | W.L. van Neerven, A. Vogt (Leiden University) | NNLO evolution of deep-inelastic structure functions: the non-singlet
case | 29 pages, LaTeX, 13 eps-figures | Nucl.Phys.B568:263-286,2000 | 10.1016/S0550-3213(99)00668-9 | INLO-PUB 14/99 | hep-ph | null | We study the next-to-next-to-leading order (NNLO) evolution of flavour
non-singlet quark densities and structure functions in massless perturbative
QCD. Present information on the corresponding three-loop splitting functions is
used to derive parametrizations of these quantities, including Bjorken-x
dependent estimates of their residual uncertainties. Compact expressions are
also provided for the exactly known, but rather involved two-loop coefficient
functions. The size of the NNLO corrections and their effect on the stability
under variations of the renormalization scale are investigated. The residual
uncertainty of the three-loop splitting functions does not lead to appreciable
effects for x > 10^-2. Inclusion of the NNLO contributions reduces the main
theoretical uncertainty of alpha_s determinations from non-singlet scaling
violations by more than a factor of two.
| [
{
"created": "Fri, 23 Jul 1999 13:09:28 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"van Neerven",
"W. L.",
"",
"Leiden University"
],
[
"Vogt",
"A.",
"",
"Leiden University"
]
] | We study the next-to-next-to-leading order (NNLO) evolution of flavour non-singlet quark densities and structure functions in massless perturbative QCD. Present information on the corresponding three-loop splitting functions is used to derive parametrizations of these quantities, including Bjorken-x dependent estimates of their residual uncertainties. Compact expressions are also provided for the exactly known, but rather involved two-loop coefficient functions. The size of the NNLO corrections and their effect on the stability under variations of the renormalization scale are investigated. The residual uncertainty of the three-loop splitting functions does not lead to appreciable effects for x > 10^-2. Inclusion of the NNLO contributions reduces the main theoretical uncertainty of alpha_s determinations from non-singlet scaling violations by more than a factor of two. |
1111.3354 | S.Rick Gupta | Rick S. Gupta | Probing Quartic Neutral Gauge Boson Couplings using diffractive photon
fusion at the LHC | 37 pages, 6 figures | null | 10.1103/PhysRevD.85.014006 | CERN-PH-TH/2011-284; MCTP-11-40 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A complete list of operators contributing at the lowest order to Quartic
Neutral Gauge Boson Couplings involving photons and Z-bosons, is presented. We
show that, for the couplings we consider, the lowest order contribution is from
dimension 8 operators in the case when a light Higgs is present and from
dimension 6 operators in the higgsless case where electroweak symmetry is
non-linearly realized. We also show that these operators are generated by
exchange of the Kaluza-Klein partners of the graviton in extra-dimensional
models. We then explore the possibility of probing these couplings in the
diffractive photon fusion processes pp(\gamma\gamma \to \gamma\gamma)pp and
pp(\gamma\gamma \to ZZ)pp at the 14 TeV LHC. We find that the \gamma \gamma
\gamma \gamma-coupling can be probed most sensitively and values as small as
1/(1.8 TeV)^{4} can be measured. For the \gamma\gamma ZZ-coupling, values as
small as 1/(850 GeV)^{4} and 1/(1.9 TeV)^2 can be probed in the light Higgs and
higgsless cases respectively, which is an improvement by orders of magnitude
over existing limits.
| [
{
"created": "Mon, 14 Nov 2011 20:48:22 GMT",
"version": "v1"
}
] | 2013-05-30 | [
[
"Gupta",
"Rick S.",
""
]
] | A complete list of operators contributing at the lowest order to Quartic Neutral Gauge Boson Couplings involving photons and Z-bosons, is presented. We show that, for the couplings we consider, the lowest order contribution is from dimension 8 operators in the case when a light Higgs is present and from dimension 6 operators in the higgsless case where electroweak symmetry is non-linearly realized. We also show that these operators are generated by exchange of the Kaluza-Klein partners of the graviton in extra-dimensional models. We then explore the possibility of probing these couplings in the diffractive photon fusion processes pp(\gamma\gamma \to \gamma\gamma)pp and pp(\gamma\gamma \to ZZ)pp at the 14 TeV LHC. We find that the \gamma \gamma \gamma \gamma-coupling can be probed most sensitively and values as small as 1/(1.8 TeV)^{4} can be measured. For the \gamma\gamma ZZ-coupling, values as small as 1/(850 GeV)^{4} and 1/(1.9 TeV)^2 can be probed in the light Higgs and higgsless cases respectively, which is an improvement by orders of magnitude over existing limits. |
2112.03920 | Robert McGehee | Gilly Elor, Robert McGehee, Aaron Pierce | Maximizing Direct Detection with Highly Interactive Particle Relic Dark
Matter | 5+3 pages, 3 figures. v2: published in PRL with minor revisions | Phys. Rev. Lett. 130, 031803 (2023) | 10.1103/PhysRevLett.130.031803 | LCTP-21-26, MITP-21-044 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We estimate the maximum direct detection cross section for sub-GeV dark
matter (DM) scattering off nucleons. For DM masses in the range $10 \text{ keV
}- 100 \text{ MeV}$, cross sections greater than $10^{-36}$- $10^{-30}
\,\text{cm}^2$ seem implausible. We present a DM candidate which realizes this
maximum cross section: HighlY interactive ParticlE Relics (HYPERs). After
HYPERs freeze-in, a dark sector phase transition decreases the mediator's mass.
This increases the HYPER's direct detection cross section without impacting its
abundance or measurements of Big Bang Nucleosynthesis and the Cosmic Microwave
Background.
| [
{
"created": "Tue, 7 Dec 2021 19:00:00 GMT",
"version": "v1"
},
{
"created": "Fri, 20 Jan 2023 22:08:40 GMT",
"version": "v2"
}
] | 2023-01-24 | [
[
"Elor",
"Gilly",
""
],
[
"McGehee",
"Robert",
""
],
[
"Pierce",
"Aaron",
""
]
] | We estimate the maximum direct detection cross section for sub-GeV dark matter (DM) scattering off nucleons. For DM masses in the range $10 \text{ keV }- 100 \text{ MeV}$, cross sections greater than $10^{-36}$- $10^{-30} \,\text{cm}^2$ seem implausible. We present a DM candidate which realizes this maximum cross section: HighlY interactive ParticlE Relics (HYPERs). After HYPERs freeze-in, a dark sector phase transition decreases the mediator's mass. This increases the HYPER's direct detection cross section without impacting its abundance or measurements of Big Bang Nucleosynthesis and the Cosmic Microwave Background. |
1507.01132 | Kamel Khelifa-Kerfa | Kamel Khelifa-Kerfa, Yazid Delenda | Eikonal gluon radiation at finite-Nc beyond 2 loops | To appear in the proceedings of the XXIII International Workshop on
Deep-Inelastic Scattering and Related Subjects, April 27 - May 1, 2015,
Dallas, Texas, USA | POS(DIS2015)143 | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present first calculations of QCD matrix-elements in perturbation theory
at finite Nc beyond 2 loops in the eikonal approximation for e+ e- annihilation
processes. For the emission of n soft energy-ordered gluons we solve both the
colour and kinematic structures at a given order in perturbation theory by
means of a Mathematica program that relies solely on a recently developed
Mathematica code, ColorMath, that evaluates the trace of products of colour
matrices. At large Nc, our squared amplitudes reduce to those already known in
the literature.
| [
{
"created": "Sat, 4 Jul 2015 17:54:50 GMT",
"version": "v1"
}
] | 2015-07-07 | [
[
"Khelifa-Kerfa",
"Kamel",
""
],
[
"Delenda",
"Yazid",
""
]
] | We present first calculations of QCD matrix-elements in perturbation theory at finite Nc beyond 2 loops in the eikonal approximation for e+ e- annihilation processes. For the emission of n soft energy-ordered gluons we solve both the colour and kinematic structures at a given order in perturbation theory by means of a Mathematica program that relies solely on a recently developed Mathematica code, ColorMath, that evaluates the trace of products of colour matrices. At large Nc, our squared amplitudes reduce to those already known in the literature. |
1804.02636 | Xing-Gang Wu | Shi Bu, Xing-Gang Wu, Jian-Ming Shen, and Jun Zeng | Properties of the Free Energy Density Using the Principle of Maximum
Conformality | 7 pages, 4 figures | Chin. Phys. C 42 (2018) 083105 | 10.1088/1674-1137/42/8/083105 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a detailed study on the properties of the free energy density at
the high temperature by applying the principle of maximum conformality (PMC)
scale-setting method within the effective field theory. The PMC utilizes the
renormalization group equation recursively to identify the occurrence and
pattern of the non-conformal $\{\beta_i\}$-terms, and determines the optimal
renormalization scale at each order. Our analysis shows that a more accurate
free energy density up to $g_s^5$-order level without renormalization scale
dependence can be achieved by applying the PMC. We also observe that by using a
smaller factorization scale around the effective parameter $m_E$, the PMC
prediction shall be consistent with the Lattice QCD prediction derived at the
low temperature.
| [
{
"created": "Sun, 8 Apr 2018 06:26:39 GMT",
"version": "v1"
}
] | 2018-07-31 | [
[
"Bu",
"Shi",
""
],
[
"Wu",
"Xing-Gang",
""
],
[
"Shen",
"Jian-Ming",
""
],
[
"Zeng",
"Jun",
""
]
] | We present a detailed study on the properties of the free energy density at the high temperature by applying the principle of maximum conformality (PMC) scale-setting method within the effective field theory. The PMC utilizes the renormalization group equation recursively to identify the occurrence and pattern of the non-conformal $\{\beta_i\}$-terms, and determines the optimal renormalization scale at each order. Our analysis shows that a more accurate free energy density up to $g_s^5$-order level without renormalization scale dependence can be achieved by applying the PMC. We also observe that by using a smaller factorization scale around the effective parameter $m_E$, the PMC prediction shall be consistent with the Lattice QCD prediction derived at the low temperature. |
1503.01773 | Nicholas Rodd Mr | Gilly Elor, Nicholas L. Rodd and Tracy R. Slatyer | Multi-Step Cascade Annihilations of Dark Matter and the Galactic Center
Excess | 18 pages, 15 figures, 2 tables; comments welcome. Updated to
published version | Phys. Rev. D 91, 103531 (2015) | 10.1103/PhysRevD.91.103531 | MIT-CTP/4647 | hep-ph astro-ph.CO astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | If dark matter is embedded in a non-trivial dark sector, it may annihilate
and decay to lighter dark-sector states which subsequently decay to the
Standard Model. Such scenarios - with annihilation followed by cascading
dark-sector decays - can explain the apparent excess GeV gamma-rays identified
in the central Milky Way, while evading bounds from dark matter direct
detection experiments. Each 'step' in the cascade will modify the observable
signatures of dark matter annihilation and decay, shifting the resulting
photons and other final state particles to lower energies and broadening their
spectra. We explore, in a model-independent way, the effect of multi-step
dark-sector cascades on the preferred regions of parameter space to explain the
GeV excess. We find that the broadening effects of multi-step cascades can
admit final states dominated by particles that would usually produce too
sharply peaked photon spectra; in general, if the cascades are hierarchical
(each particle decays to substantially lighter particles), the preferred mass
range for the dark matter is in all cases 20-150 GeV. Decay chains that have
nearly-degenerate steps, where the products are close to half the mass of the
progenitor, can admit much higher DM masses. We map out the region of
mass/cross-section parameter space where cascades (degenerate, hierarchical or
a combination) can fit the signal, for a range of final states. In the current
work, we study multi-step cascades in the context of explaining the GeV excess,
but many aspects of our results are general and can be extended to other
applications.
| [
{
"created": "Thu, 5 Mar 2015 21:00:13 GMT",
"version": "v1"
},
{
"created": "Sat, 6 Jun 2015 16:08:08 GMT",
"version": "v2"
}
] | 2015-06-09 | [
[
"Elor",
"Gilly",
""
],
[
"Rodd",
"Nicholas L.",
""
],
[
"Slatyer",
"Tracy R.",
""
]
] | If dark matter is embedded in a non-trivial dark sector, it may annihilate and decay to lighter dark-sector states which subsequently decay to the Standard Model. Such scenarios - with annihilation followed by cascading dark-sector decays - can explain the apparent excess GeV gamma-rays identified in the central Milky Way, while evading bounds from dark matter direct detection experiments. Each 'step' in the cascade will modify the observable signatures of dark matter annihilation and decay, shifting the resulting photons and other final state particles to lower energies and broadening their spectra. We explore, in a model-independent way, the effect of multi-step dark-sector cascades on the preferred regions of parameter space to explain the GeV excess. We find that the broadening effects of multi-step cascades can admit final states dominated by particles that would usually produce too sharply peaked photon spectra; in general, if the cascades are hierarchical (each particle decays to substantially lighter particles), the preferred mass range for the dark matter is in all cases 20-150 GeV. Decay chains that have nearly-degenerate steps, where the products are close to half the mass of the progenitor, can admit much higher DM masses. We map out the region of mass/cross-section parameter space where cascades (degenerate, hierarchical or a combination) can fit the signal, for a range of final states. In the current work, we study multi-step cascades in the context of explaining the GeV excess, but many aspects of our results are general and can be extended to other applications. |
hep-ph/9909553 | Hong soon-tae | Soon-Tae Hong | Strange Form Factors of Octet and Decuplet Baryons | 5 pages, Talk given at the 12th Nuclear Physics Summer School and
Symposium and the 11th International Light-Cone Workshop "New Directions in
QCD," 21-25 June 1999, Kyungju, Korea | AIP Conf.Proc.494:423-426,1999 | 10.1063/1.1301691 | null | hep-ph | null | The strange form factors of baryon octet are evaluated, in the chiral models
with the general chiral SU(3) group structure, to yield the theoretical
predictions comparable to the recent experimental data of SAMPLE Collaboration
and to study the spin symmetries. Other model predictions are also briefly
reviewed to compare with our results and then the strange form factors of
baryon octet and decuplet are predicted.
| [
{
"created": "Wed, 29 Sep 1999 14:36:12 GMT",
"version": "v1"
}
] | 2010-12-13 | [
[
"Hong",
"Soon-Tae",
""
]
] | The strange form factors of baryon octet are evaluated, in the chiral models with the general chiral SU(3) group structure, to yield the theoretical predictions comparable to the recent experimental data of SAMPLE Collaboration and to study the spin symmetries. Other model predictions are also briefly reviewed to compare with our results and then the strange form factors of baryon octet and decuplet are predicted. |
1503.06671 | Igor Strakovsky | V. E. Tarasov (ITEP), W. J. Briscoe (GW), M. Dieterle (Basel U.), B.
Krusche (Basel U.), A. E. Kudryavtsev (ITEP/GW), M. Ostrick (JGU), I. I.
Strakovsky (GW) | On the Extraction of Cross Sections for pi0 and eta Photoproduction off
Neutrons from Deuteron Data | 16 pages, 5 figures; v2 fixed several minor typos | null | 10.1134/S1063778816020186 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the procedure of extracting the photoproduction cross section for
neutral pseudoscalar mesons off neutrons from deuteron data. The main statement
is that the final-state interaction (FSI) corrections for the proton and
neutron target are in general not equal, but for pi0 production there are
special cases were they have to be identical and there are large regions in the
parameter space of incident photon energy and pion polar angle, \theta^*, where
they happen to be quite similar. The corrections for both target nucleons are
practically identical for $\pi_0$ production in the energy range of the
Delta(1232)3/2+ resonance due to the specific isospin structure of this
excitation. Also above the $\Delta$-isobar range large differences between
proton and neutron correction factors are only predicted for extreme forward
angles ($\theta^*$ < 20 deg), but the results are similar for larger angles.
Numerical results for the gp-->pi0p and gn-->pi0n correction factors are
discussed. Also the model description for the available data on the
differential gd-->pi0pn cross sections are given.
| [
{
"created": "Mon, 23 Mar 2015 14:56:59 GMT",
"version": "v1"
},
{
"created": "Tue, 24 Mar 2015 18:42:49 GMT",
"version": "v2"
}
] | 2016-11-18 | [
[
"Tarasov",
"V. E.",
"",
"ITEP"
],
[
"Briscoe",
"W. J.",
"",
"GW"
],
[
"Dieterle",
"M.",
"",
"Basel U."
],
[
"Krusche",
"B.",
"",
"Basel U."
],
[
"Kudryavtsev",
"A. E.",
"",
"ITEP/GW"
],
[
"Ostrick",
"M.",
"",
"JGU"
],
[
"Strakovsky",
"I. I.",
"",
"GW"
]
] | We discuss the procedure of extracting the photoproduction cross section for neutral pseudoscalar mesons off neutrons from deuteron data. The main statement is that the final-state interaction (FSI) corrections for the proton and neutron target are in general not equal, but for pi0 production there are special cases were they have to be identical and there are large regions in the parameter space of incident photon energy and pion polar angle, \theta^*, where they happen to be quite similar. The corrections for both target nucleons are practically identical for $\pi_0$ production in the energy range of the Delta(1232)3/2+ resonance due to the specific isospin structure of this excitation. Also above the $\Delta$-isobar range large differences between proton and neutron correction factors are only predicted for extreme forward angles ($\theta^*$ < 20 deg), but the results are similar for larger angles. Numerical results for the gp-->pi0p and gn-->pi0n correction factors are discussed. Also the model description for the available data on the differential gd-->pi0pn cross sections are given. |
hep-ph/0006141 | Jeno E. Kontros | J. Kontros, K. Kontros, A. Lengyel | Pomeron models and exchange degeneracy of the Regge trajectories | 6 pages, LaTeX, 5 figures | null | null | null | hep-ph | null | Two models for the Pomeron, supplemented by exchange degenerate sub-leading
Regge trajectories, are fitted to the forward scattering data for a number of
reactions. By considering new Pomeron models, we extend the recent results of
the COMPAS group, being consistent with our predecessors.
| [
{
"created": "Tue, 13 Jun 2000 18:13:02 GMT",
"version": "v1"
},
{
"created": "Fri, 14 Jul 2000 21:37:24 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Kontros",
"J.",
""
],
[
"Kontros",
"K.",
""
],
[
"Lengyel",
"A.",
""
]
] | Two models for the Pomeron, supplemented by exchange degenerate sub-leading Regge trajectories, are fitted to the forward scattering data for a number of reactions. By considering new Pomeron models, we extend the recent results of the COMPAS group, being consistent with our predecessors. |
2310.07796 | Fernando Alvarado | Fernando Alvarado, Di An, Luis Alvarez-Ruso and Stefan Leupold | Light quark mass dependence of nucleon electromagnetic form factors in
dispersively modified chiral perturbation theory | 27 pages, 13 figures. It contains supplementary material "anc" | null | null | null | hep-ph hep-lat hep-th nucl-th | http://creativecommons.org/licenses/by/4.0/ | The nucleon isovector electromagnetic form factors are calculated up to
next-to-next-to-leading order by combining relativistic chiral perturbation
theory (ChPT) of pion, nucleon, and $\Delta$(1232) with dispersion theory. We
specifically address the light-quark mass dependence of the form factors,
achieving a good description of recent Lattice QCD results over a range of $Q^2
< 0.6$ GeV$^2$ and $M_{\pi} < 350$ MeV. For the Dirac form factor, the
combination of ChPT and dispersion theory outperforms the pure dispersive and
pure ChPT descriptions. For the Pauli form factor, the combined calculation
leads to results comparable to the purely dispersive ones. The anomalous
magnetic moment and the Dirac and Pauli radii are extracted.
| [
{
"created": "Wed, 11 Oct 2023 18:31:34 GMT",
"version": "v1"
},
{
"created": "Fri, 15 Dec 2023 09:07:44 GMT",
"version": "v2"
}
] | 2023-12-18 | [
[
"Alvarado",
"Fernando",
""
],
[
"An",
"Di",
""
],
[
"Alvarez-Ruso",
"Luis",
""
],
[
"Leupold",
"Stefan",
""
]
] | The nucleon isovector electromagnetic form factors are calculated up to next-to-next-to-leading order by combining relativistic chiral perturbation theory (ChPT) of pion, nucleon, and $\Delta$(1232) with dispersion theory. We specifically address the light-quark mass dependence of the form factors, achieving a good description of recent Lattice QCD results over a range of $Q^2 < 0.6$ GeV$^2$ and $M_{\pi} < 350$ MeV. For the Dirac form factor, the combination of ChPT and dispersion theory outperforms the pure dispersive and pure ChPT descriptions. For the Pauli form factor, the combined calculation leads to results comparable to the purely dispersive ones. The anomalous magnetic moment and the Dirac and Pauli radii are extracted. |
hep-ph/0312231 | Andrew Akeroyd | A.G. Akeroyd, Marco A. Diaz, Francisco J. Pacheco | Double fermiophobic Higgs boson production at the LHC and LC | 19 pages, 9 figures, expanded discussion, fig.1 changed slightly,
version to appear in Phys.Rev.D | Phys.Rev.D70:075002,2004 | 10.1103/PhysRevD.70.075002 | KIAS-P03080, UCCHEP/24-03 | hep-ph | null | We consider the phenomenology of a fermiophobic Higgs boson (h_f) at the
Large Hadron Collider (LHC) and a e+e- Linear Collider (LC). At both machines
the standard production mechanisms which rely on the coupling h_fVV (V=W,Z) can
be very suppressed at large tan beta. In such cases the complementary channels
pp to H^\pm h_f, A^0 h_f and e+e- to A^0 h_f offer promising cross-sections.
Together with the potentially large branching ratios for H^\pm to h_fW* and A^0
to h_fZ*, these mechanisms would give rise to double h_f production, leading to
signatures of gamma gamma gamma gamma, gamma gamma VV and VVVV.
| [
{
"created": "Wed, 17 Dec 2003 06:32:53 GMT",
"version": "v1"
},
{
"created": "Thu, 26 Aug 2004 01:53:01 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Akeroyd",
"A. G.",
""
],
[
"Diaz",
"Marco A.",
""
],
[
"Pacheco",
"Francisco J.",
""
]
] | We consider the phenomenology of a fermiophobic Higgs boson (h_f) at the Large Hadron Collider (LHC) and a e+e- Linear Collider (LC). At both machines the standard production mechanisms which rely on the coupling h_fVV (V=W,Z) can be very suppressed at large tan beta. In such cases the complementary channels pp to H^\pm h_f, A^0 h_f and e+e- to A^0 h_f offer promising cross-sections. Together with the potentially large branching ratios for H^\pm to h_fW* and A^0 to h_fZ*, these mechanisms would give rise to double h_f production, leading to signatures of gamma gamma gamma gamma, gamma gamma VV and VVVV. |
1701.04561 | Chao-Hsi Chang | Xu-Chang Zheng, Chao-Hsi Chang, Tai-Fu Feng, Zan Pan | The NLO QCD corrections to $B_c$($B_c^*$) production around $Z$ pole at
an $e^+e^-$ collider | 11 pages, 10 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Production of the $B_c$ and $B_c^*$ mesons at $Z$-factory (an $e^+e^-$
collider running at energies around $Z$ pole) is calculated up-to the
next-to-leading order (NLO) QCD corrections. The results show that the
dependence of the total cross sections on the renormalization scale $\mu$ is
reduced by the corrections, and the NLO corrections enhance the production
cross section by $52\%$($33\%$) when the renormalization scale is taken at
$\mu=2m_b$. For experimental observations of the $B_c$ and $B_c^*$ mesons, the
differential cross sections for the production are also analyzed up-to the NLO
accuracy.
| [
{
"created": "Tue, 17 Jan 2017 08:20:23 GMT",
"version": "v1"
},
{
"created": "Mon, 13 Mar 2017 04:28:20 GMT",
"version": "v2"
},
{
"created": "Sat, 15 Jul 2017 13:46:32 GMT",
"version": "v3"
}
] | 2017-07-18 | [
[
"Zheng",
"Xu-Chang",
""
],
[
"Chang",
"Chao-Hsi",
""
],
[
"Feng",
"Tai-Fu",
""
],
[
"Pan",
"Zan",
""
]
] | Production of the $B_c$ and $B_c^*$ mesons at $Z$-factory (an $e^+e^-$ collider running at energies around $Z$ pole) is calculated up-to the next-to-leading order (NLO) QCD corrections. The results show that the dependence of the total cross sections on the renormalization scale $\mu$ is reduced by the corrections, and the NLO corrections enhance the production cross section by $52\%$($33\%$) when the renormalization scale is taken at $\mu=2m_b$. For experimental observations of the $B_c$ and $B_c^*$ mesons, the differential cross sections for the production are also analyzed up-to the NLO accuracy. |
hep-ph/0302188 | Heather E. Logan | Tao Han, Heather E. Logan, Bob McElrath, and Lian-Tao Wang | Loop induced decays of the Little Higgs: H --> gg, gamma gamma | 16 pages, 7 figures; v2: note added to comment on a related paper,
submitted to PLB; v3: mistake corrected in yt, yT and yWL in Eq.4; Figs 3-7,
Table 1, and numbers in conclusions updated | Phys.Lett. B563 (2003) 191-202; Erratum-ibid. B603 (2004) 257-259 | 10.1016/S0370-2693(03)00657-9 | MADPH-03-1319 | hep-ph | null | We analyze the loop induced decays of the Higgs boson into pairs of gluons
and photons in the Littlest Higgs model. We find that the deviation of the
partial widths for these decays relative to their Standard Model values scales
with 1/f^2, where f ~ TeV is the mass scale of the new heavy particles in the
model. For f = 1 TeV, Gamma(H -> gg) is reduced by 6-10% and Gamma(H -> gamma
gamma) is reduced by 5-7% compared to their Standard Model values. While the
LHC and a linear e+e- collider would be sensitive to these deviations only for
relatively low values of f <~ 650 GeV, a photon collider could probe the
deviation in Gamma(H -> gamma gamma) up to f <~ 1.1 (0.7) TeV at the 2 (5)
sigma level.
| [
{
"created": "Thu, 20 Feb 2003 18:02:47 GMT",
"version": "v1"
},
{
"created": "Fri, 7 Mar 2003 23:41:14 GMT",
"version": "v2"
},
{
"created": "Thu, 7 Oct 2004 22:31:02 GMT",
"version": "v3"
}
] | 2010-04-05 | [
[
"Han",
"Tao",
""
],
[
"Logan",
"Heather E.",
""
],
[
"McElrath",
"Bob",
""
],
[
"Wang",
"Lian-Tao",
""
]
] | We analyze the loop induced decays of the Higgs boson into pairs of gluons and photons in the Littlest Higgs model. We find that the deviation of the partial widths for these decays relative to their Standard Model values scales with 1/f^2, where f ~ TeV is the mass scale of the new heavy particles in the model. For f = 1 TeV, Gamma(H -> gg) is reduced by 6-10% and Gamma(H -> gamma gamma) is reduced by 5-7% compared to their Standard Model values. While the LHC and a linear e+e- collider would be sensitive to these deviations only for relatively low values of f <~ 650 GeV, a photon collider could probe the deviation in Gamma(H -> gamma gamma) up to f <~ 1.1 (0.7) TeV at the 2 (5) sigma level. |
hep-ph/0507066 | J. A. R. Cembranos | J. A. R. Cembranos, A. Dobado and A. L. Maroto | Dark matter clues in the muon anomalous magnetic moment | 4 pages, 3 figures, REVTeX 4 | Phys.Rev.D73:057303,2006 | 10.1103/PhysRevD.73.057303 | UCI-TR-2005-28 | hep-ph astro-ph | null | We study the possibility to explain the non-baryonic dark matter abundance
and improve the present fits on the muon anomalous magnetic moment through the
same new physics. The only viable way to solve simultaneously both problems
which is known to date is by using supersymmetric theories. However in this
work we show that massive brane fluctuations (branons) in large
extra-dimensions models can provide a more economical alternative to
supersymmetry. This is so because the low-energy branon physics depends
effectively on only three parameters. Next collider experiments, such as LHC or
ILC, will be sensitive to branon phenomenology in the natural parameter region
where the theory is able to account for the two effects.
| [
{
"created": "Wed, 6 Jul 2005 06:22:38 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Cembranos",
"J. A. R.",
""
],
[
"Dobado",
"A.",
""
],
[
"Maroto",
"A. L.",
""
]
] | We study the possibility to explain the non-baryonic dark matter abundance and improve the present fits on the muon anomalous magnetic moment through the same new physics. The only viable way to solve simultaneously both problems which is known to date is by using supersymmetric theories. However in this work we show that massive brane fluctuations (branons) in large extra-dimensions models can provide a more economical alternative to supersymmetry. This is so because the low-energy branon physics depends effectively on only three parameters. Next collider experiments, such as LHC or ILC, will be sensitive to branon phenomenology in the natural parameter region where the theory is able to account for the two effects. |
hep-ph/0302050 | Robert L. Thews | R. L. Thews (University of Arizona) | Quarkonium Formation from Uncorrelated Quark-Antiquark Pairs | To be published in "Hard Probes in Heavy Ion Collisions at the LHC,
CERN report | null | null | null | hep-ph nucl-ex nucl-th | null | The goal of this section is to assess the possibility that quarkonium
production rates may be enhanced in nucleus-nucleus interactions at the LHC
relative to that predicted by extrapolation of processes thought to be dominant
at lower energy. This enhancement could follow from the effects of incoherent
recombination mechanisms involving uncorrelated pairs of heavy quarks and
antiquarks which result from multiple pair production. Two different approaches
have been considered: statistical hadronization and kinetic formation. Updated
predictions relevant to Pb+Pb collisions at the LHC are given.
| [
{
"created": "Fri, 7 Feb 2003 00:16:15 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Thews",
"R. L.",
"",
"University of Arizona"
]
] | The goal of this section is to assess the possibility that quarkonium production rates may be enhanced in nucleus-nucleus interactions at the LHC relative to that predicted by extrapolation of processes thought to be dominant at lower energy. This enhancement could follow from the effects of incoherent recombination mechanisms involving uncorrelated pairs of heavy quarks and antiquarks which result from multiple pair production. Two different approaches have been considered: statistical hadronization and kinetic formation. Updated predictions relevant to Pb+Pb collisions at the LHC are given. |
hep-ph/0605047 | Mikhail Shaposhnikov | Mikhail Shaposhnikov | A possible symmetry of the $\nu$MSM | 16 pages, extended version, to appear in Nucl. Phys. B | Nucl.Phys.B763:49-59,2007 | 10.1016/j.nuclphysb.2006.11.003 | CERN-PH-TH/2006-079 | hep-ph astro-ph hep-th | null | To explain the dark matter and the baryon asymmetry of the Universe, the
parameters of the $\nu$MSM (an extension of the Minimal Standard Model by three
singlet neutrinos with masses smaller than the electroweak scale) must be
fine-tuned: one of the masses should be in the ${\cal O} (10)$ keV region to
provide a candidate for the dark-matter particle, while two other masses must
be almost the same to enhance the CP-violating effects in the sterile neutrino
oscillations leading to the baryon asymmetry. We show that a specifically
defined global lepton-number symmetry, broken on the level of ${\cal O}
(10^{-4})$ leads to the required pattern of sterile neutrino masses being
consistent with the data on neutrino oscillations. Moreover, the existence of
this symmetry allows to fix the flavour structure of couplings of singlet
fermions to the particles of the Standard Model and indicates that their masses
are likely to be smaller than ${\cal O} (1)$ GeV, opening a possibility of
their search in decays of charmed, beauty and even $K$ or $\pi$-mesons.
| [
{
"created": "Thu, 4 May 2006 16:32:14 GMT",
"version": "v1"
},
{
"created": "Wed, 8 Nov 2006 09:47:59 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Shaposhnikov",
"Mikhail",
""
]
] | To explain the dark matter and the baryon asymmetry of the Universe, the parameters of the $\nu$MSM (an extension of the Minimal Standard Model by three singlet neutrinos with masses smaller than the electroweak scale) must be fine-tuned: one of the masses should be in the ${\cal O} (10)$ keV region to provide a candidate for the dark-matter particle, while two other masses must be almost the same to enhance the CP-violating effects in the sterile neutrino oscillations leading to the baryon asymmetry. We show that a specifically defined global lepton-number symmetry, broken on the level of ${\cal O} (10^{-4})$ leads to the required pattern of sterile neutrino masses being consistent with the data on neutrino oscillations. Moreover, the existence of this symmetry allows to fix the flavour structure of couplings of singlet fermions to the particles of the Standard Model and indicates that their masses are likely to be smaller than ${\cal O} (1)$ GeV, opening a possibility of their search in decays of charmed, beauty and even $K$ or $\pi$-mesons. |
hep-ph/0601240 | Artem Lipatov | A.V. Lipatov, N.P. Zotov | Beauty photoproduction at HERA: kt-factorization versus experimental
data | 29 pages, 15 figures, 2 tables | Phys.Rev.D73:114018,2006 | 10.1103/PhysRevD.73.114018 | null | hep-ph | null | We present calculations of the beauty photoproduction at HERA collider in the
framework of the kt-factorization approach. Both direct and resolved photon
contributions are taken into account. The unintegrated gluon densities in a
proton and in a photon are obtained from the full CCFM, from unified BFKL-DGLAP
evolution equations as well as from the Kimber-Martin-Ryskin prescription. We
investigate different production rates (both inclusive and associated with
hadronic jets) and compare our theoretical predictions with the recent
experimental data taken by the H1 and ZEUS collaborations. Special attention is
put on the x_{\gamma}^{obs} variable which is sensitive to the relative
contributions to the beauty production cross section.
| [
{
"created": "Sat, 28 Jan 2006 10:20:47 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Lipatov",
"A. V.",
""
],
[
"Zotov",
"N. P.",
""
]
] | We present calculations of the beauty photoproduction at HERA collider in the framework of the kt-factorization approach. Both direct and resolved photon contributions are taken into account. The unintegrated gluon densities in a proton and in a photon are obtained from the full CCFM, from unified BFKL-DGLAP evolution equations as well as from the Kimber-Martin-Ryskin prescription. We investigate different production rates (both inclusive and associated with hadronic jets) and compare our theoretical predictions with the recent experimental data taken by the H1 and ZEUS collaborations. Special attention is put on the x_{\gamma}^{obs} variable which is sensitive to the relative contributions to the beauty production cross section. |
hep-ph/9501243 | null | P.Ramond (Inst for Fundamental Theory, U Florida, Gainesville) | Probing for the Roots of the Standard Model | Lecture at the Oskar Klein Centenary Symposium. 13 pages, macros
included. | null | null | UFIFT-HEP-95-2 | hep-ph | null | The differences between the $N=0$ and $N=1$ standard models are emphasized in
formulating their short distance extension. We sketch methods to reproduce many
of the small numbers in the model in terms of scale ratios, applying see-saw
like ideas to the breaking of chiral symmetries. We sketch how the $N=1$
standard model, outfitted with an extra family Abelian symmetry to reproduce
the mass hierarchies, naturally fits superstring models, by making use of
generic non-renormalizable operators.
| [
{
"created": "Mon, 9 Jan 1995 16:46:47 GMT",
"version": "v1"
}
] | 2016-09-01 | [
[
"Ramond",
"P.",
"",
"Inst for Fundamental Theory, U Florida, Gainesville"
]
] | The differences between the $N=0$ and $N=1$ standard models are emphasized in formulating their short distance extension. We sketch methods to reproduce many of the small numbers in the model in terms of scale ratios, applying see-saw like ideas to the breaking of chiral symmetries. We sketch how the $N=1$ standard model, outfitted with an extra family Abelian symmetry to reproduce the mass hierarchies, naturally fits superstring models, by making use of generic non-renormalizable operators. |
1211.0371 | Biswajit Adhikary | Biswajit Adhikary and Probir Roy | Neutrino Yukawa textures within type-I see-saw | invited review article, to appear in a special issue on neutrinos in
the journal Advances in High Energy Physics (AHEP) | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The arbitrariness of Yukawa couplings can be reduced by the imposition of
some flavor symmetries and/or by the realization of texture zeros. We review
neutrino Yukawa textures with zeros within the framework of the type-I seesaw
with three heavy right chiral neutrinos and in the basis where the latter and
the charged leptons are mass diagonal. An assumed non-vanishing mass of every
ultralight neutrino and the observed non-decoupling of any neutrino generation
allow a maximum of four zeros in the Yukawa coupling matrix $Y_\nu$ in family
space. There are seventy two such textures. We show that the requirement of an
exact $\mu\tau$ symmetry, coupled with the observational constraints, reduces
these seventy two allowed textures to only four corresponding to just two
different forms of the light neutrino mass matrix $M_{\nu A}/M_{\nu B}$,
resulting in an inverted/normal mass ordering. The effect of each of these on
measurable quantities can be described, apart from an overall factor of the
neutrino mass scale, in terms of two real parameters and a phase angle all of
which are within very constrained ranges. The masses and Majorana phases of
ultralight neutrinos are predicted within definite ranges with $3\sigma$
laboratory and cosmological observational inputs. The rate for $0\nu\beta\beta$
decay, though generally below the reach of planned experiments, could approach
it in some parameteric regions. Within the same framework, we also study Yukawa
textures with a fewer number of zeros, but with exact $\mu\tau$ symmetry. We
further formulate the detailed scheme of the explicit breaking of $\mu\tau$
symmetry in terms of three small parameters for allowed four zero textures. The
observed sizable mixing between the first and third generations of neutrinos is
shown to follow for a suitable choice of these symmetry breaking parameters.
| [
{
"created": "Fri, 2 Nov 2012 05:39:12 GMT",
"version": "v1"
}
] | 2012-11-05 | [
[
"Adhikary",
"Biswajit",
""
],
[
"Roy",
"Probir",
""
]
] | The arbitrariness of Yukawa couplings can be reduced by the imposition of some flavor symmetries and/or by the realization of texture zeros. We review neutrino Yukawa textures with zeros within the framework of the type-I seesaw with three heavy right chiral neutrinos and in the basis where the latter and the charged leptons are mass diagonal. An assumed non-vanishing mass of every ultralight neutrino and the observed non-decoupling of any neutrino generation allow a maximum of four zeros in the Yukawa coupling matrix $Y_\nu$ in family space. There are seventy two such textures. We show that the requirement of an exact $\mu\tau$ symmetry, coupled with the observational constraints, reduces these seventy two allowed textures to only four corresponding to just two different forms of the light neutrino mass matrix $M_{\nu A}/M_{\nu B}$, resulting in an inverted/normal mass ordering. The effect of each of these on measurable quantities can be described, apart from an overall factor of the neutrino mass scale, in terms of two real parameters and a phase angle all of which are within very constrained ranges. The masses and Majorana phases of ultralight neutrinos are predicted within definite ranges with $3\sigma$ laboratory and cosmological observational inputs. The rate for $0\nu\beta\beta$ decay, though generally below the reach of planned experiments, could approach it in some parameteric regions. Within the same framework, we also study Yukawa textures with a fewer number of zeros, but with exact $\mu\tau$ symmetry. We further formulate the detailed scheme of the explicit breaking of $\mu\tau$ symmetry in terms of three small parameters for allowed four zero textures. The observed sizable mixing between the first and third generations of neutrinos is shown to follow for a suitable choice of these symmetry breaking parameters. |
0912.3997 | Kyriakos Tamvakis | J. Rizos and K. Tamvakis | Hierarchical Neutrino Masses and Mixing in Flipped-SU(5) | 10 pages | Phys.Lett.B685:67-71,2010 | 10.1016/j.physletb.2010.01.038 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the problem of neutrino masses and mixing in the framework of
flipped SU(5). The right-handed neutrino mass, generated through the operation
of a seesaw mechanism by a sector of gauge singlets, leads naturally, at a
subsequent level, to the standard seesaw mechanism resulting into three light
neutrino states with masses of the desired phenomenological order of magnitude.
In this framework we study simple Ansatze for the singlet couplings for which
hierarchical neutrino masses emerge naturally, parametrized in terms of the
Cabbibo parameter. The resulting neutrino mixing matrices are characterized by
a hierarchical structure, in which theta-(13) is always predicted to be the
smallest. Finally, we discuss a possible factorized parametrization of the
neutrino mass that, in addition to Cabbibo mixing, encodes also mixing due to
the singlet sector.
| [
{
"created": "Sun, 20 Dec 2009 10:28:06 GMT",
"version": "v1"
}
] | 2010-04-30 | [
[
"Rizos",
"J.",
""
],
[
"Tamvakis",
"K.",
""
]
] | We consider the problem of neutrino masses and mixing in the framework of flipped SU(5). The right-handed neutrino mass, generated through the operation of a seesaw mechanism by a sector of gauge singlets, leads naturally, at a subsequent level, to the standard seesaw mechanism resulting into three light neutrino states with masses of the desired phenomenological order of magnitude. In this framework we study simple Ansatze for the singlet couplings for which hierarchical neutrino masses emerge naturally, parametrized in terms of the Cabbibo parameter. The resulting neutrino mixing matrices are characterized by a hierarchical structure, in which theta-(13) is always predicted to be the smallest. Finally, we discuss a possible factorized parametrization of the neutrino mass that, in addition to Cabbibo mixing, encodes also mixing due to the singlet sector. |
1703.10916 | Dimitrios Karamitros | Dimitrios Karamitros | A Fermionic bi-Doublet Effective Field Theory for Dark Matter | 14 pages. To appear in the Proceedings of Corfu Summer Institute 2016
"School and Workshops on Elementary Particle Physics and Gravity" September
2016 Corfu, Greece | null | null | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study an effective field theory which includes the Standard Model extended
by a Dark Sector consisting of two fermionic $SU(2)_{L}$-doublets. A $Z_2$
parity guarantees that, after electroweak symmetry breaking, the lightest
neutral particle is stable, acting as a WIMP. The dark sector interacts with
the Higgs and gauge bosons through renormalizable and non-renormalizable $d=5$
operators. We find that a WIMP with a mass around the electroweak scale, i.e.
accessible at the LHC, is consistent with collider and astrophysical data only
when non-trivial magnetic dipole interactions with the gauge bosons exist.
| [
{
"created": "Fri, 31 Mar 2017 14:34:56 GMT",
"version": "v1"
}
] | 2017-04-03 | [
[
"Karamitros",
"Dimitrios",
""
]
] | We study an effective field theory which includes the Standard Model extended by a Dark Sector consisting of two fermionic $SU(2)_{L}$-doublets. A $Z_2$ parity guarantees that, after electroweak symmetry breaking, the lightest neutral particle is stable, acting as a WIMP. The dark sector interacts with the Higgs and gauge bosons through renormalizable and non-renormalizable $d=5$ operators. We find that a WIMP with a mass around the electroweak scale, i.e. accessible at the LHC, is consistent with collider and astrophysical data only when non-trivial magnetic dipole interactions with the gauge bosons exist. |
hep-ph/9902298 | D. P. Roy | D.P. Roy | SUSY and SUGRA Signatures at Hadron Colliders | Invited Talk at the 13th Intl. Conf. on Hadron Collider Physics,
Mumbai, India 14-20 January 1999, 9 pages, latex, including 5 eps figures | null | null | TIFR/TH/99-05 | hep-ph | null | After a brief introduction to SUSY I discuss the missing-p_T signature for
superparticles from R-parity conservation and the multilepton signature, which
follows from their cascade decay. The GUT and SUGRA constraints on the SUSY
mass parameters are discussed along with the resulting SUSY signals at LHC.
Finally I consider the effect of relaxing the SUGRA constraint on these
signals.
| [
{
"created": "Wed, 10 Feb 1999 12:47:45 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Roy",
"D. P.",
""
]
] | After a brief introduction to SUSY I discuss the missing-p_T signature for superparticles from R-parity conservation and the multilepton signature, which follows from their cascade decay. The GUT and SUGRA constraints on the SUSY mass parameters are discussed along with the resulting SUSY signals at LHC. Finally I consider the effect of relaxing the SUGRA constraint on these signals. |
0805.1603 | Rui Santos | Abdesslam Arhrib, Rachid Benbrik, R.B. Guedes and R. Santos | Search for a light fermiophobic Higgs boson produced via gluon fusion at
Hadron Colliders | 9 pages, 13 figures | Phys.Rev.D78:075002,2008 | 10.1103/PhysRevD.78.075002 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this study, we propose new Higgs production mechanisms with multi-photon
final states in the fermiophobic limit of the Two Higgs Doublet Model. The
processes are: gg -> hh, gg -> H h followed by H -> h h and gg -> A h followed
by A -> h Z. In the fermiophobic limit, gg -> h h and gg -> A h -> h h Z would
give rise to 4 photon signature while gg -> H h -> h h h can give a 6 photon
final state. We show that both the Fermilab Tevatron and CERN's Large Hadron
Collider can probe a substantial slice of the parameter space in this
fermiophobic scenario of the Two Higgs Doublet Model. If observed the above
processes can give some information on the triple Higgs couplings involved.
| [
{
"created": "Mon, 12 May 2008 10:17:28 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Arhrib",
"Abdesslam",
""
],
[
"Benbrik",
"Rachid",
""
],
[
"Guedes",
"R. B.",
""
],
[
"Santos",
"R.",
""
]
] | In this study, we propose new Higgs production mechanisms with multi-photon final states in the fermiophobic limit of the Two Higgs Doublet Model. The processes are: gg -> hh, gg -> H h followed by H -> h h and gg -> A h followed by A -> h Z. In the fermiophobic limit, gg -> h h and gg -> A h -> h h Z would give rise to 4 photon signature while gg -> H h -> h h h can give a 6 photon final state. We show that both the Fermilab Tevatron and CERN's Large Hadron Collider can probe a substantial slice of the parameter space in this fermiophobic scenario of the Two Higgs Doublet Model. If observed the above processes can give some information on the triple Higgs couplings involved. |
1110.6452 | Muneyuki Ishida | Vernon Barger and Muneyuki Ishida | Randall-Sundrum Reality at the LHC | 14 page including 5 figures | null | 10.1016/j.physletb.2012.01.073 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The radion is expected to be the first signal of the Randall-Sundrum (RS)
model. We explore the possibility of finding it in the ongoing Higgs searches
at the LHC. The little RS model (LRS), which has a fundamental scale at about
1000 TeV, is excluded over wide ranges of the radion mass from the latest $WW$
and gamma gamma data by ATLAS and CMS.
| [
{
"created": "Fri, 28 Oct 2011 20:06:07 GMT",
"version": "v1"
},
{
"created": "Wed, 2 Nov 2011 00:07:58 GMT",
"version": "v2"
},
{
"created": "Tue, 6 Mar 2012 19:10:07 GMT",
"version": "v3"
}
] | 2015-06-03 | [
[
"Barger",
"Vernon",
""
],
[
"Ishida",
"Muneyuki",
""
]
] | The radion is expected to be the first signal of the Randall-Sundrum (RS) model. We explore the possibility of finding it in the ongoing Higgs searches at the LHC. The little RS model (LRS), which has a fundamental scale at about 1000 TeV, is excluded over wide ranges of the radion mass from the latest $WW$ and gamma gamma data by ATLAS and CMS. |
hep-ph/9504348 | "V. A." Khoze | VALERY A. KHOZE | ON MEASURING THE $\gamma \gamma$ WIDTH OF THE INTERMEDIATE- MASS HIGGS
AT A PHOTON LINEAR COLLIDER | 7 pages, LATEX file, hard copies of 2 figs. availabl upon request | null | null | Talk at the Photon'95, Sheffield, April 8-15, 1995 | hep-ph | null | The identification of the intermediate-mass Higgs process $\gamma \gamma
\rightarrow H \rightarrow b\overline{b}$ will be one of the most important
goals of a future photon linear collider. Backgrounds from the continuum
$\gamma \gamma \rightarrow c\overline{c}, b\overline{b}$ leading-order
processes can be suppressed by using polarized photon beams in the $J_z = 0$
initial-state. The radiative processes $\gamma \gamma \rightarrow c\overline{c}
g, b\overline{b} g$ can mimic the two-jet topology of the Higgs signal and
provide the dominant background in the $J_z = 0$ channel. Particularly
problematic is the $\gamma \gamma \rightarrow c\overline{c} g \rightarrow 2$
jets process. The effects of imposing additional cuts are investigated and it
is shown that the radiative background could be reduced to a manageable level.
| [
{
"created": "Thu, 20 Apr 1995 14:13:36 GMT",
"version": "v1"
}
] | 2009-09-25 | [
[
"KHOZE",
"VALERY A.",
""
]
] | The identification of the intermediate-mass Higgs process $\gamma \gamma \rightarrow H \rightarrow b\overline{b}$ will be one of the most important goals of a future photon linear collider. Backgrounds from the continuum $\gamma \gamma \rightarrow c\overline{c}, b\overline{b}$ leading-order processes can be suppressed by using polarized photon beams in the $J_z = 0$ initial-state. The radiative processes $\gamma \gamma \rightarrow c\overline{c} g, b\overline{b} g$ can mimic the two-jet topology of the Higgs signal and provide the dominant background in the $J_z = 0$ channel. Particularly problematic is the $\gamma \gamma \rightarrow c\overline{c} g \rightarrow 2$ jets process. The effects of imposing additional cuts are investigated and it is shown that the radiative background could be reduced to a manageable level. |
0905.0633 | Joerg Jaeckel | Felix Bruemmer, Joerg Jaeckel and Valentin V. Khoze | Magnetic Mixing -- Electric Minicharges from Magnetic Monopoles | 17 pages, 1 figure | JHEP 0906:037,2009 | 10.1088/1126-6708/2009/06/037 | IPPP/09/36; DCPT/09/72 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Many extensions of the Standard Model require the existence of a "hidden"
sector. We consider settings where the hidden sector in the infrared contains a
U(1) gauge factor with magnetic monopoles, for instance 't Hooft-Polyakov
monopoles of an underlying non-abelian gauge group. In the presence of CP
violation these monopoles acquire an electric charge in the hidden sector due
to the Witten effect. We show that quite generally they also acquire (small)
electric charges under the visible electromagnetic gauge group. This is a
result of "magnetic mixing" which, as we show, often arises as a natural
partner of kinetic mixing. Both kinetic and magnetic mixing are naturally
induced radiatively even if the low-energy U(1)s arise from a single
non-abelian gauge group. We argue that the hidden sector monopoles can be light
and their electric minicharges could thus be testable in current and near
future low-energy experiments.
| [
{
"created": "Tue, 5 May 2009 15:53:49 GMT",
"version": "v1"
}
] | 2009-06-23 | [
[
"Bruemmer",
"Felix",
""
],
[
"Jaeckel",
"Joerg",
""
],
[
"Khoze",
"Valentin V.",
""
]
] | Many extensions of the Standard Model require the existence of a "hidden" sector. We consider settings where the hidden sector in the infrared contains a U(1) gauge factor with magnetic monopoles, for instance 't Hooft-Polyakov monopoles of an underlying non-abelian gauge group. In the presence of CP violation these monopoles acquire an electric charge in the hidden sector due to the Witten effect. We show that quite generally they also acquire (small) electric charges under the visible electromagnetic gauge group. This is a result of "magnetic mixing" which, as we show, often arises as a natural partner of kinetic mixing. Both kinetic and magnetic mixing are naturally induced radiatively even if the low-energy U(1)s arise from a single non-abelian gauge group. We argue that the hidden sector monopoles can be light and their electric minicharges could thus be testable in current and near future low-energy experiments. |
1701.06932 | Abdulkadir Senol | H. Denizli, A. Senol, A. Yilmaz, I. T. Cakir, H. Karadeniz, O. Cakir | Top quark FCNC couplings at future circular hadron electron colliders | 11 pages, 4 Figures, 4 Tables, to appear in Phys. Rev. D | Phys. Rev. D 96, 015024 (2017) | 10.1103/PhysRevD.96.015024 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A study of single top quark production via flavor changing neutral current
interactions at $tq\gamma$ vertices is performed at future circular hadron
electron collider. The signal cross sections for the processes $e^{-}p\to
e^{-}W^{\pm}q+X$ and $e^{-}p\to e^{-}W^{\pm}bq+X$ in the collision of electron
beam with energy $E_e=$ 60 GeV and proton beam with energy $E_p=$ 50 TeV are
calculated. In the analysis, the invariant mass distributions of three jets
reconstructing top quark mass, requiring one b-tagged jet and other two jets
reconstructing the $W$ mass are used to count signal and background events
after all selection cuts. The upper limits on the anomalous flavor changing
neutral current $tq\gamma$ couplings are found to be $\lambda_q < $ 0.01 at
future circular hadron electron collider for $L_{int}=100$ fb$^{-1}$ with the
fast simulation of detector effects. Signal significance depending on the
couplings $\lambda_q$ is analyzed and an enhanced sensitivity is found to the
branching ratio BR($t\to q\gamma$) at the future circular hadron electron
collider when compared to the current experimental results.
| [
{
"created": "Tue, 24 Jan 2017 15:33:32 GMT",
"version": "v1"
},
{
"created": "Wed, 26 Jul 2017 20:07:44 GMT",
"version": "v2"
}
] | 2017-07-28 | [
[
"Denizli",
"H.",
""
],
[
"Senol",
"A.",
""
],
[
"Yilmaz",
"A.",
""
],
[
"Cakir",
"I. T.",
""
],
[
"Karadeniz",
"H.",
""
],
[
"Cakir",
"O.",
""
]
] | A study of single top quark production via flavor changing neutral current interactions at $tq\gamma$ vertices is performed at future circular hadron electron collider. The signal cross sections for the processes $e^{-}p\to e^{-}W^{\pm}q+X$ and $e^{-}p\to e^{-}W^{\pm}bq+X$ in the collision of electron beam with energy $E_e=$ 60 GeV and proton beam with energy $E_p=$ 50 TeV are calculated. In the analysis, the invariant mass distributions of three jets reconstructing top quark mass, requiring one b-tagged jet and other two jets reconstructing the $W$ mass are used to count signal and background events after all selection cuts. The upper limits on the anomalous flavor changing neutral current $tq\gamma$ couplings are found to be $\lambda_q < $ 0.01 at future circular hadron electron collider for $L_{int}=100$ fb$^{-1}$ with the fast simulation of detector effects. Signal significance depending on the couplings $\lambda_q$ is analyzed and an enhanced sensitivity is found to the branching ratio BR($t\to q\gamma$) at the future circular hadron electron collider when compared to the current experimental results. |
hep-ph/9407348 | Michael A. Doncheski | Michael A. Doncheski, Stephen Godfrey and K. Andrew Peterson | Probing the Heavy Quark Content of the Photon Using b Tagging at High
Energy $e\gamma$ and $e^+e^-$ Colliders | 15 pages, LaTeX, 10 postscript files; extensive modifications from
previous version | Phys.Rev. D55 (1997) 183-189 | 10.1103/PhysRevD.55.183 | OCIP/C-94-2 | hep-ph | null | We suggest a method for probing the quark content of the photon using $b$
tagging at high energy $e^+e^-$ and $e\gamma$ colliders. We find that heavy
quark tagging provides a sensitive and effective probe of the quark content of
the photon especially in the low $x$-region where the various models differ the
most. This process is complementary to others that have been studied in the
literature and can contribute to more precise determinations of quark and gluon
distributions inside the photon.
| [
{
"created": "Thu, 21 Jul 1994 13:26:31 GMT",
"version": "v1"
},
{
"created": "Thu, 3 Oct 1996 23:26:18 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Doncheski",
"Michael A.",
""
],
[
"Godfrey",
"Stephen",
""
],
[
"Peterson",
"K. Andrew",
""
]
] | We suggest a method for probing the quark content of the photon using $b$ tagging at high energy $e^+e^-$ and $e\gamma$ colliders. We find that heavy quark tagging provides a sensitive and effective probe of the quark content of the photon especially in the low $x$-region where the various models differ the most. This process is complementary to others that have been studied in the literature and can contribute to more precise determinations of quark and gluon distributions inside the photon. |
hep-ph/9803428 | Gudrun Hiller | A. Ali and G. Hiller (DESY, Hamburg) | Perturbative QCD- and Power-Corrected Hadron Spectra and Spectral
Moments in the Decay $B \to X_s \ell^+ \ell^-$ | 44 pages, 15 figure (require epsf.sty);, March 1998; Several typos
and composition errors corrected; four references added; no change in
formulae or results | Phys.Rev.D58:074001,1998 | 10.1103/PhysRevD.58.074001 | DESY 98-030 | hep-ph | null | We compute the leading order (in $\alpha_s$) perturbative QCD and power
($1/m_b^2)$ corrections to the hadronic invariant mass and hadron energy
spectra in the decay $B \to X_s \ell^+ \ell^-$ in standard model. This is done
both by using the heavy quark expansion technique (HQET) and a perturbative-QCD
improved Fermi motion (FM) model which takes into account $B$-meson
wave-function effects. The corrections in the hadron energy ($E_H$) spectrum
are found to be small over a good part of this spectrum in both the methods.
However, the expansion in $1/m_b$ in HQET fails near the lower kinematic
end-point and at the $c\bar{c}$ threshold. The hadronic invariant mass ($S_H$)
spectrum is calculable only over a limited range $S_H > \bar{\Lambda}m_B$ in
the heavy quark expansion, where $\bar{\Lambda} \simeq m_B-m_b$. We also
present results for the first two hadronic moments $< S_H^n>$ and $< E_H^n>$,
$n=1,2$, working out their sensitivity on the HQET and FM model parameters. For
equivalent values of these parameters, the moments in these methods are
remarkably close to each other. Using the FM model, we study the effect of the
experimental cuts, used recently by the CLEO collaboration in searching for the
decay $B \to X_s \ell^+ \ell^-$, on the hadron spectra and hadronic invariant
mass moments. The constraints following from assumed values of $< S_H^n>$ on
the HQET parameters $\lambda_1$ and $\bar{\Lambda}$ are worked out. Data from
the forthcoming B facilities could be used to measure the short-distance
contribution in $B \to X_s \ell^+ \ell^-$ and determine the HQET parameters
$\lambda_1$ and $\bar{\Lambda}$. This could be combined with complementary
constrains in $B \to X \ell \nu_\ell$ to determine them precisely.
| [
{
"created": "Mon, 23 Mar 1998 19:24:09 GMT",
"version": "v1"
},
{
"created": "Fri, 27 Mar 1998 10:39:14 GMT",
"version": "v2"
}
] | 2011-01-27 | [
[
"Ali",
"A.",
"",
"DESY, Hamburg"
],
[
"Hiller",
"G.",
"",
"DESY, Hamburg"
]
] | We compute the leading order (in $\alpha_s$) perturbative QCD and power ($1/m_b^2)$ corrections to the hadronic invariant mass and hadron energy spectra in the decay $B \to X_s \ell^+ \ell^-$ in standard model. This is done both by using the heavy quark expansion technique (HQET) and a perturbative-QCD improved Fermi motion (FM) model which takes into account $B$-meson wave-function effects. The corrections in the hadron energy ($E_H$) spectrum are found to be small over a good part of this spectrum in both the methods. However, the expansion in $1/m_b$ in HQET fails near the lower kinematic end-point and at the $c\bar{c}$ threshold. The hadronic invariant mass ($S_H$) spectrum is calculable only over a limited range $S_H > \bar{\Lambda}m_B$ in the heavy quark expansion, where $\bar{\Lambda} \simeq m_B-m_b$. We also present results for the first two hadronic moments $< S_H^n>$ and $< E_H^n>$, $n=1,2$, working out their sensitivity on the HQET and FM model parameters. For equivalent values of these parameters, the moments in these methods are remarkably close to each other. Using the FM model, we study the effect of the experimental cuts, used recently by the CLEO collaboration in searching for the decay $B \to X_s \ell^+ \ell^-$, on the hadron spectra and hadronic invariant mass moments. The constraints following from assumed values of $< S_H^n>$ on the HQET parameters $\lambda_1$ and $\bar{\Lambda}$ are worked out. Data from the forthcoming B facilities could be used to measure the short-distance contribution in $B \to X_s \ell^+ \ell^-$ and determine the HQET parameters $\lambda_1$ and $\bar{\Lambda}$. This could be combined with complementary constrains in $B \to X \ell \nu_\ell$ to determine them precisely. |
1912.04163 | Essodjolo Kpatcha | Essodjolo Kpatcha, Inaki Lara, Daniel E. Lopez-Fogliani, Carlos Munoz,
Natsumi Nagata | Explaining muon $g-2$ data in the $\mu\nu$SSM | Version published in EPJC. A compiling issue has been resolved in
Fig. 11. 39 pages, 14 figures, 3 tables. Analyses of the scalar sector of the
{\mu}{\nu}SSM in arXiv:1907.02092 and arXiv:1910.08062 are used | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyze the anomalous magnetic moment of the muon $g-2$ in the
$\mu\nu$SSM. This $R$-parity violating model solves the $\mu$ problem
reproducing simultaneously neutrino data, only with the addition of
right-handed neutrinos. In the framework of the $\mu\nu$SSM, light left
muon-sneutrino and wino masses can be naturally obtained driven by neutrino
physics. This produces an increase of the dominant chargino-sneutrino loop
contribution to muon $g-2$, solving the gap between the theoretical computation
and the experimental data. To analyze the parameter space, we sample the
$\mu\nu$SSM using a likelihood data-driven method, paying special attention to
reproduce the current experimental data on neutrino and Higgs physics, as well
as flavor observables such as $B$ and $\mu$ decays. We then apply the
constraints from LHC searches for events with multi-leptons + MET on the viable
regions found. They can probe these regions through chargino-chargino,
chargino-neutralino and neutralino-neutralino pair production. We conclude that
significant regions of the parameter space of the $\mu\nu$SSM can explain muon
$g-2$ data.
| [
{
"created": "Fri, 6 Dec 2019 18:57:45 GMT",
"version": "v1"
},
{
"created": "Wed, 7 Oct 2020 14:07:08 GMT",
"version": "v2"
},
{
"created": "Wed, 13 Jan 2021 14:19:36 GMT",
"version": "v3"
}
] | 2021-01-14 | [
[
"Kpatcha",
"Essodjolo",
""
],
[
"Lara",
"Inaki",
""
],
[
"Lopez-Fogliani",
"Daniel E.",
""
],
[
"Munoz",
"Carlos",
""
],
[
"Nagata",
"Natsumi",
""
]
] | We analyze the anomalous magnetic moment of the muon $g-2$ in the $\mu\nu$SSM. This $R$-parity violating model solves the $\mu$ problem reproducing simultaneously neutrino data, only with the addition of right-handed neutrinos. In the framework of the $\mu\nu$SSM, light left muon-sneutrino and wino masses can be naturally obtained driven by neutrino physics. This produces an increase of the dominant chargino-sneutrino loop contribution to muon $g-2$, solving the gap between the theoretical computation and the experimental data. To analyze the parameter space, we sample the $\mu\nu$SSM using a likelihood data-driven method, paying special attention to reproduce the current experimental data on neutrino and Higgs physics, as well as flavor observables such as $B$ and $\mu$ decays. We then apply the constraints from LHC searches for events with multi-leptons + MET on the viable regions found. They can probe these regions through chargino-chargino, chargino-neutralino and neutralino-neutralino pair production. We conclude that significant regions of the parameter space of the $\mu\nu$SSM can explain muon $g-2$ data. |
1602.00937 | Ya-ping Xie | Ya-ping Xie and Xurong Chen | The coherent cross section of vector mesons in ultraperipheral PbPb
collisions at the LHC | null | null | 10.1140/epjc/s10052-016-4170-1 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The coherent cross section of $J/\psi$, $\rho$, $\phi$ are computed in dipole
model in the ultraperipheral PbPb collisions, the IP-Sat and IIM model are
applied in the calculation of the differential cross section of the dipole
scattering off the nucleon, three kinds of forward vector meson wave functions
are used in the overlap. The prediction of $J/\psi$ and $\rho$ is compared with
the experimental data of the ALICE Collaboration, and the prediction of $\phi$
is also given in this paper.
| [
{
"created": "Tue, 2 Feb 2016 14:22:16 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Mar 2016 13:04:09 GMT",
"version": "v2"
}
] | 2021-01-13 | [
[
"Xie",
"Ya-ping",
""
],
[
"Chen",
"Xurong",
""
]
] | The coherent cross section of $J/\psi$, $\rho$, $\phi$ are computed in dipole model in the ultraperipheral PbPb collisions, the IP-Sat and IIM model are applied in the calculation of the differential cross section of the dipole scattering off the nucleon, three kinds of forward vector meson wave functions are used in the overlap. The prediction of $J/\psi$ and $\rho$ is compared with the experimental data of the ALICE Collaboration, and the prediction of $\phi$ is also given in this paper. |
hep-ph/0205249 | Anna M. Stasto | A.M. Stasto | Saturation at low x and nonlinear evolution | 12 pages, 5 figures, talk given at the Epiphany Conference, Cracow,
3-6 January 2002 | Acta Phys.Polon. B33 (2002) 1571-1582 | null | null | hep-ph | null | In this talk the results of the analytical and numerical analysis of the
nonlinear Balitsky-Kovchegov equation are presented. The characteristic BFKL
diffusion into infrared regime is suppressed by the generation of the
saturation scale. We identify the scaling and linear regimes for the solution.
We also study the impact of subleading corrections onto the nonlinear
evolution.
| [
{
"created": "Wed, 22 May 2002 14:22:52 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Stasto",
"A. M.",
""
]
] | In this talk the results of the analytical and numerical analysis of the nonlinear Balitsky-Kovchegov equation are presented. The characteristic BFKL diffusion into infrared regime is suppressed by the generation of the saturation scale. We identify the scaling and linear regimes for the solution. We also study the impact of subleading corrections onto the nonlinear evolution. |
2003.07366 | Marco Chianese Dr | Marco Chianese, Bowen Fu, Stephen F. King | Impact of Higgs portal on gravity-mediated production of superheavy dark
matter | 14 pages, 5 figures. Updated to match version published in JCAP | JCAP06(2020)019 | 10.1088/1475-7516/2020/06/019 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the so-called Planckian Interacting Dark Matter (PIDM) scenario,
superheavy dark matter particles are produced after inflation by
gravity-mediated interactions through the freeze-in mechanism. In the minimal
PIDM model, the absence of any additional direct coupling with Standard Model
particles is assumed. However, for scalar dark matter particles there is no
symmetry that suppresses the Higgs portal coupling. In this paper, we therefore
study the impact of a non-zero interaction with the Higgs field on the PIDM
paradigm for scalar dark matter. In particular, we fully explore the model
parameter space in order to identify the allowed regions where the correct dark
matter abundance is achieved. Moreover, we provide the threshold value for the
Higgs portal coupling below which the corresponding production processes are
sub-dominant and the minimal PIDM scenario is preserved. For a benchmark scalar
dark matter mass of $10^{15}$ GeV, we find that the Higgs portal coupling has
to be smaller than $5.1 \times 10^{-8}$ ($1.1 \times 10^{-7}$) for
instantaneous (non-instantaneous) reheating.
| [
{
"created": "Mon, 16 Mar 2020 18:00:01 GMT",
"version": "v1"
},
{
"created": "Tue, 9 Jun 2020 08:29:54 GMT",
"version": "v2"
}
] | 2020-06-11 | [
[
"Chianese",
"Marco",
""
],
[
"Fu",
"Bowen",
""
],
[
"King",
"Stephen F.",
""
]
] | In the so-called Planckian Interacting Dark Matter (PIDM) scenario, superheavy dark matter particles are produced after inflation by gravity-mediated interactions through the freeze-in mechanism. In the minimal PIDM model, the absence of any additional direct coupling with Standard Model particles is assumed. However, for scalar dark matter particles there is no symmetry that suppresses the Higgs portal coupling. In this paper, we therefore study the impact of a non-zero interaction with the Higgs field on the PIDM paradigm for scalar dark matter. In particular, we fully explore the model parameter space in order to identify the allowed regions where the correct dark matter abundance is achieved. Moreover, we provide the threshold value for the Higgs portal coupling below which the corresponding production processes are sub-dominant and the minimal PIDM scenario is preserved. For a benchmark scalar dark matter mass of $10^{15}$ GeV, we find that the Higgs portal coupling has to be smaller than $5.1 \times 10^{-8}$ ($1.1 \times 10^{-7}$) for instantaneous (non-instantaneous) reheating. |
hep-ph/9707369 | Gabriel Lopez | M. Beuthe, G. Lopez Castro and J. Pestieau | Field theory approach to K0-K0bar and B0-B0bar systems | Latex, 19 pages | Int.J.Mod.Phys. A13 (1998) 3587-3600 | 10.1142/S0217751X98001682 | UCL-IPT-97-09 | hep-ph | null | Quantum field theory provides a consistent framework to deal with unstable
particles. We present here an approach based on field theory to describe the
production and decay of unstable $K^0-\bar{K^0}$ and $B^0-\bar{B^0}$ mixed
systems. The formalism is applied to compute the time evolution amplitudes of
$K^0$ and $\bar{K^0}$ studied in DAPHNE and CPLEAR experiments. We also
introduce a new set of parameters that describe CP violation in $ K \to \pi\pi$
decays without recourse to isospin decomposition of the decay amplitudes.
| [
{
"created": "Thu, 17 Jul 1997 10:15:10 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Beuthe",
"M.",
""
],
[
"Castro",
"G. Lopez",
""
],
[
"Pestieau",
"J.",
""
]
] | Quantum field theory provides a consistent framework to deal with unstable particles. We present here an approach based on field theory to describe the production and decay of unstable $K^0-\bar{K^0}$ and $B^0-\bar{B^0}$ mixed systems. The formalism is applied to compute the time evolution amplitudes of $K^0$ and $\bar{K^0}$ studied in DAPHNE and CPLEAR experiments. We also introduce a new set of parameters that describe CP violation in $ K \to \pi\pi$ decays without recourse to isospin decomposition of the decay amplitudes. |
hep-ph/9601286 | null | Maria J.Herrero | Introduction To The Symmetry Breaking Sector | 45 pages, Latex, figures not included . Hard copys of figures
available on request | null | null | FTUAM/Jan/1996/1 | hep-ph hep-ex | null | The basic ingredients of the Spontaneous Symmetry Breaking Phenomenon and of
the Higgs Mechanism are reviewed in these lectures of pedagogical character.
Some relevant topics related with the breaking $\gs \rightarrow U(1)_{\rm em}$
are selected and discussed here. A brief survey of the experimental Higgs
particle searches and the theoretical limits on $\mh$ are also presented. The
main features of the most popular models of symmetry breaking beyond the
Standard Model are briefly considered. It includes a short summary of the Higgs
Sector in the Minimal SUSY Model, the basic ideas of Technicolor models and a
brief introduction to Strongly Interacting Scalar sectors and to the Effective
Chiral Lagrangian Approach to the Electroweak Theory.
| [
{
"created": "Wed, 17 Jan 1996 19:00:47 GMT",
"version": "v1"
}
] | 2009-09-25 | [
[
"Herrero",
"Maria J.",
""
]
] | The basic ingredients of the Spontaneous Symmetry Breaking Phenomenon and of the Higgs Mechanism are reviewed in these lectures of pedagogical character. Some relevant topics related with the breaking $\gs \rightarrow U(1)_{\rm em}$ are selected and discussed here. A brief survey of the experimental Higgs particle searches and the theoretical limits on $\mh$ are also presented. The main features of the most popular models of symmetry breaking beyond the Standard Model are briefly considered. It includes a short summary of the Higgs Sector in the Minimal SUSY Model, the basic ideas of Technicolor models and a brief introduction to Strongly Interacting Scalar sectors and to the Effective Chiral Lagrangian Approach to the Electroweak Theory. |
hep-ph/0702184 | Alejandro Ibarra | Wilfried Buchmuller, Laura Covi, Koichi Hamaguchi, Alejandro Ibarra,
Tsutomu Yanagida | Gravitino Dark Matter in R-Parity Breaking Vacua | 18 pages. Typos corrected | JHEP 0703:037,2007 | 10.1088/1126-6708/2007/03/037 | DESY 06-244, UT-07-03 | hep-ph astro-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that in the case of small R-parity and lepton number breaking
couplings, primordial nucleosynthesis, thermal leptogenesis and gravitino dark
matter are naturally consistent for gravitino masses m_{3/2} \gsim 5 GeV. We
present a model where R-parity breaking is tied to B-L breaking, which predicts
the needed small couplings. The metastable next-to-lightest superparticle has a
decay length that is typically larger than a few centimeters, with
characteristic signatures at the LHC. The photon flux produced by relic
gravitino decays may be part of the apparent excess in the extragalactic
diffuse gamma-ray flux obtained from the EGRET data for a gravitino mass
m_{3/2} \sim 10 GeV. In this case, a clear signal can be expected from GLAST in
the near future.
| [
{
"created": "Mon, 19 Feb 2007 14:55:59 GMT",
"version": "v1"
},
{
"created": "Mon, 27 Oct 2008 07:34:11 GMT",
"version": "v2"
}
] | 2010-04-06 | [
[
"Buchmuller",
"Wilfried",
""
],
[
"Covi",
"Laura",
""
],
[
"Hamaguchi",
"Koichi",
""
],
[
"Ibarra",
"Alejandro",
""
],
[
"Yanagida",
"Tsutomu",
""
]
] | We show that in the case of small R-parity and lepton number breaking couplings, primordial nucleosynthesis, thermal leptogenesis and gravitino dark matter are naturally consistent for gravitino masses m_{3/2} \gsim 5 GeV. We present a model where R-parity breaking is tied to B-L breaking, which predicts the needed small couplings. The metastable next-to-lightest superparticle has a decay length that is typically larger than a few centimeters, with characteristic signatures at the LHC. The photon flux produced by relic gravitino decays may be part of the apparent excess in the extragalactic diffuse gamma-ray flux obtained from the EGRET data for a gravitino mass m_{3/2} \sim 10 GeV. In this case, a clear signal can be expected from GLAST in the near future. |
1602.06112 | Antonio Rodr\'iguez S\'anchez | A. Rodr\'iguez-S\'anchez, M. Gonz\'alez-Alonso, A. Pich | Updated determination of chiral couplings and vacuum condensates from
hadronic tau decay data | 25 pages, 8 figures, Preprint numbers: IFIC/16-08 FTUV/16-0219 | Phys. Rev. D 94, 014017 (2016) | 10.1103/PhysRevD.94.014017 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyze the lowest spectral moments of the left-right two-point
correlation function, using all known short-distance constraints and the
recently updated ALEPH V-A spectral function from tau decays. This information
is used to determine the low-energy couplings L10 and C87 of chiral
perturbation theory and the lowest-dimensional contributions to the Operator
Product Expansion of the left-right correlator. A detailed statistical analysis
is implemented to assess the theoretical uncertainties, including violations of
quark-hadron duality.
| [
{
"created": "Fri, 19 Feb 2016 11:14:54 GMT",
"version": "v1"
}
] | 2016-07-20 | [
[
"Rodríguez-Sánchez",
"A.",
""
],
[
"González-Alonso",
"M.",
""
],
[
"Pich",
"A.",
""
]
] | We analyze the lowest spectral moments of the left-right two-point correlation function, using all known short-distance constraints and the recently updated ALEPH V-A spectral function from tau decays. This information is used to determine the low-energy couplings L10 and C87 of chiral perturbation theory and the lowest-dimensional contributions to the Operator Product Expansion of the left-right correlator. A detailed statistical analysis is implemented to assess the theoretical uncertainties, including violations of quark-hadron duality. |
hep-ph/9607288 | Ezio Maina | A. Ballestrero, E. Maina and M. Pizzio (U. of Torino and INFN-Torino) | $b \bar b W^+ W^-$ production at hadron colliders. Top signal and
irreducible backgrounds | 13 LaTex pages, 2 figs using feynman.sty, 5 ps figures | Phys.Lett.B387:411-418,1996 | 10.1016/0370-2693(96)01048-9 | DFTT 32/96 | hep-ph | null | We compute complete tree level matrix elements for $gg , q \bar q \rightarrow
b \bar b W^+W^-$. We analyze the irreducible backgrounds to top signal at the
Tevatron and at the LHC. Their contribution to the total cross section is about
$5 \%$ at the LHC, due to single resonant channels. Several distributions with
contributions from signal and backgrounds are presented.
| [
{
"created": "Thu, 11 Jul 1996 08:20:34 GMT",
"version": "v1"
}
] | 2008-12-22 | [
[
"Ballestrero",
"A.",
"",
"U. of Torino and INFN-Torino"
],
[
"Maina",
"E.",
"",
"U. of Torino and INFN-Torino"
],
[
"Pizzio",
"M.",
"",
"U. of Torino and INFN-Torino"
]
] | We compute complete tree level matrix elements for $gg , q \bar q \rightarrow b \bar b W^+W^-$. We analyze the irreducible backgrounds to top signal at the Tevatron and at the LHC. Their contribution to the total cross section is about $5 \%$ at the LHC, due to single resonant channels. Several distributions with contributions from signal and backgrounds are presented. |
1507.05543 | Fabio Siringo | Fabio Siringo | Perturbation theory of non-perturbative QCD | null | null | null | null | hep-ph hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Perturbation theory is shown to be working in the IR limit of pure SU(3)
Yang-Mills theory in Landau gauge by an unconventional setting of the
perturbative expansion. A dynamical mass is predicted for the gluon and the
lattice data are reproduced fairly well by a second-order expansion, without
any free parameter. The effective running coupling is small in the IR and the
approximation can be improved by inclusion of higher order terms.
| [
{
"created": "Mon, 20 Jul 2015 15:52:54 GMT",
"version": "v1"
}
] | 2015-07-21 | [
[
"Siringo",
"Fabio",
""
]
] | Perturbation theory is shown to be working in the IR limit of pure SU(3) Yang-Mills theory in Landau gauge by an unconventional setting of the perturbative expansion. A dynamical mass is predicted for the gluon and the lattice data are reproduced fairly well by a second-order expansion, without any free parameter. The effective running coupling is small in the IR and the approximation can be improved by inclusion of higher order terms. |
1112.5122 | Mario da Silva | M. L. L. da Silva, M. V. T. Machado | Investigating photoproduction of scalar mesons at medium energies | 4 pages, 3 figures, 2 tables. Version to be published in Physical
Review C | null | 10.1103/PhysRevC.86.015209 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this letter we study the photoproduction of scalar mesons in the
intermediate energies considering distinct mixing scenarios in the description
of meson physical states. The differential and integrated total cross section
are computed for the cases of the mesons a_0(980), f_0(1500) and f_0(1710)
focusing the GlueX energy regime with photon energy equal to 9 GeV. Our results
indicate that light-quark scalar meson photoproduction is well suited for
studying hybrid mesons structure.
| [
{
"created": "Wed, 21 Dec 2011 18:25:04 GMT",
"version": "v1"
},
{
"created": "Thu, 19 Jul 2012 17:40:08 GMT",
"version": "v2"
}
] | 2013-05-30 | [
[
"da Silva",
"M. L. L.",
""
],
[
"Machado",
"M. V. T.",
""
]
] | In this letter we study the photoproduction of scalar mesons in the intermediate energies considering distinct mixing scenarios in the description of meson physical states. The differential and integrated total cross section are computed for the cases of the mesons a_0(980), f_0(1500) and f_0(1710) focusing the GlueX energy regime with photon energy equal to 9 GeV. Our results indicate that light-quark scalar meson photoproduction is well suited for studying hybrid mesons structure. |
0706.3135 | Helen Matskevich | S.M. Gerasyuta and E.E. Matskevich | Excited $(70,L^+)$ baryon resonances in the relativistic quark model | latex, 23 pages, 3 figures | Phys.Rev.D76:116004,2007 | 10.1103/PhysRevD.76.116004 | null | hep-ph | null | The masses of positive parity $(70,0^+)$ and $(70,2^+)$ nonstrange and
strange baryons are calculated in the relativistic quark model. The
relativistic three-quark equations of the $(70,L^+)$ multiplets are found 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 amplitude are obtained. The calculated mass values of the
$(70,L^+)$ multiplets are in good agreement with the experimental ones.
| [
{
"created": "Thu, 21 Jun 2007 12:19:11 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Gerasyuta",
"S. M.",
""
],
[
"Matskevich",
"E. E.",
""
]
] | The masses of positive parity $(70,0^+)$ and $(70,2^+)$ nonstrange and strange baryons are calculated in the relativistic quark model. The relativistic three-quark equations of the $(70,L^+)$ multiplets are found 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 amplitude are obtained. The calculated mass values of the $(70,L^+)$ multiplets are in good agreement with the experimental ones. |
2402.19417 | Yu Hamada | Minoru Eto, Yu Hamada, Ryusuke Jinno, Muneto Nitta, and Masatoshi
Yamada | Neutrino zeromodes on electroweak strings in light of topological
insulators | 43 pages, 8 figures; v2: typos corrected, refs added, and some minor
changes | JHEP 06 (2024) 062 | 10.1007/JHEP06(2024)062 | KEK-TH-2592, DESY-24-003, RESCEU-2/24, YGHP-24-01 | hep-ph cond-mat.mes-hall hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We examine neutrino zeromode solutions on the electroweak $Z$-string and
their effect on the stability of the string in the standard model and its
extensions. We propose using topological invariants constructed from the
momentum (and real) space topology of Green's functions, often used for
investigating edge modes in condensed matter physics. We analyze the standard
model and then examine type-I and type-II extensions of the neutrino sector as
well as their hybrid. Based on this analysis, we also comment on proposals in
the literature to stabilize the $Z$-string.
| [
{
"created": "Thu, 29 Feb 2024 18:15:16 GMT",
"version": "v1"
},
{
"created": "Fri, 7 Jun 2024 11:23:57 GMT",
"version": "v2"
}
] | 2024-07-19 | [
[
"Eto",
"Minoru",
""
],
[
"Hamada",
"Yu",
""
],
[
"Jinno",
"Ryusuke",
""
],
[
"Nitta",
"Muneto",
""
],
[
"Yamada",
"Masatoshi",
""
]
] | We examine neutrino zeromode solutions on the electroweak $Z$-string and their effect on the stability of the string in the standard model and its extensions. We propose using topological invariants constructed from the momentum (and real) space topology of Green's functions, often used for investigating edge modes in condensed matter physics. We analyze the standard model and then examine type-I and type-II extensions of the neutrino sector as well as their hybrid. Based on this analysis, we also comment on proposals in the literature to stabilize the $Z$-string. |
0805.1752 | Ted Rogers | J. C. Collins and T. C. Rogers | The Gluon Distribution Function and Factorization in Feynman Gauge | 15 pages, 31 figures | Phys.Rev.D78:054012,2008 | 10.1103/PhysRevD.78.054012 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A complication in proving factorization theorems in Feynman gauge is that
individual graphs give a super-leading power of the hard scale when all the
gluons inducing the hard scattering are longitudinally polarized. With the aid
of an example in gluon-mediated deep inelastic scattering, we show that,
although the super-leading terms cancel after a sum over graphs, there is a
residual non-zero leading term from longitudinally polarized gluons. This is
due to the non-zero transverse momenta of the gluons in the target. The
non-cancellation, due to the non-Abelian property of the gauge group, is
necessary to obtain the correct form of the gluon distribution function as a
gauge-invariant matrix element.
| [
{
"created": "Mon, 12 May 2008 21:51:49 GMT",
"version": "v1"
},
{
"created": "Wed, 3 Sep 2008 12:21:09 GMT",
"version": "v2"
}
] | 2009-11-13 | [
[
"Collins",
"J. C.",
""
],
[
"Rogers",
"T. C.",
""
]
] | A complication in proving factorization theorems in Feynman gauge is that individual graphs give a super-leading power of the hard scale when all the gluons inducing the hard scattering are longitudinally polarized. With the aid of an example in gluon-mediated deep inelastic scattering, we show that, although the super-leading terms cancel after a sum over graphs, there is a residual non-zero leading term from longitudinally polarized gluons. This is due to the non-zero transverse momenta of the gluons in the target. The non-cancellation, due to the non-Abelian property of the gauge group, is necessary to obtain the correct form of the gluon distribution function as a gauge-invariant matrix element. |
hep-ph/9711408 | Michael Spira | Michael Spira | Squark and Gluino Production at Hadron Colliders | 13 pages, latex, 9 figures, Contribution to the proceedings of the
International Workshop on Quantum Effects in the MSSM, 9--13 September 1997,
Barcelona, Spain | null | null | CERN-TH/97-325 | hep-ph | null | The theoretical status of squark and gluino production at present and future
hadron colliders is reviewed. I shall concentrate on the evaluation of SUSY-QCD
corrections to the production cross sections and their phenomenological
implications.
| [
{
"created": "Thu, 20 Nov 1997 18:01:21 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Spira",
"Michael",
""
]
] | The theoretical status of squark and gluino production at present and future hadron colliders is reviewed. I shall concentrate on the evaluation of SUSY-QCD corrections to the production cross sections and their phenomenological implications. |
2012.01214 | Emidio Gabrielli | Marco Fabbrichesi and Emidio Gabrielli | Searching for the dark sector in two-body anti-muon decay with the
polarization of monochromatic positrons | 7 pages, 4 figures. Same as published version, new results included,
a few typos corrected | Phys. Rev. D 104, 015039 (2021) | 10.1103/PhysRevD.104.015039 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The $\mu^+ \to e^+ X$ decay, where $X$ is a dark sector boson, provides one
of the strongest available bounds on the scale of dark sector interactions. The
$X$ boson can be an axion or a dark photon. We show that the concurrent
determination of the anti-muon and positron polarizations makes possible to
distinguish with a confidence level of 99% between the two dark sector portals
with as few as 6 observed events in the case of the massless dark photon.
Instead, the massive spin-1, dimension 4 dark portal cannot be distinguished
from the axion-like case. We also discuss the possibility that the $X$ boson be
a massive spin-2 particle.
| [
{
"created": "Wed, 2 Dec 2020 13:55:34 GMT",
"version": "v1"
},
{
"created": "Wed, 22 Sep 2021 18:26:27 GMT",
"version": "v2"
}
] | 2021-09-24 | [
[
"Fabbrichesi",
"Marco",
""
],
[
"Gabrielli",
"Emidio",
""
]
] | The $\mu^+ \to e^+ X$ decay, where $X$ is a dark sector boson, provides one of the strongest available bounds on the scale of dark sector interactions. The $X$ boson can be an axion or a dark photon. We show that the concurrent determination of the anti-muon and positron polarizations makes possible to distinguish with a confidence level of 99% between the two dark sector portals with as few as 6 observed events in the case of the massless dark photon. Instead, the massive spin-1, dimension 4 dark portal cannot be distinguished from the axion-like case. We also discuss the possibility that the $X$ boson be a massive spin-2 particle. |
1005.3457 | Peter Zeiler Skands | Peter Zeiler Skands | Tuning Monte Carlo Generators: The Perugia Tunes | 46 pages | Phys.Rev.D82:074018,2010 | 10.1103/PhysRevD.82.074018 | MCnet/10/08, CERN-PH-TH/2010-113 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present 9 new tunes of the pT-ordered shower and underlying-event model in
PYTHIA 6.4. These "Perugia" tunes update and supersede the older "S0" family.
The data sets used to constrain the models include hadronic Z0 decays at LEP,
Tevatron minimum-bias data at 630, 1800, and 1960 GeV, Tevatron Drell-Yan data
at 1800 and 1960 GeV, and SPS min-bias data at 200, 546, and 900 GeV. In
addition to the central parameter set, called "Perugia 0", we introduce a set
of 8 related "Perugia Variations" that attempt to systematically explore soft,
hard, parton density, and colour structure variations in the theoretical
parameters. Based on these variations, a best-guess prediction of the charged
track multiplicity in inelastic, nondiffractive minimum-bias events at the LHC
is made. Note that these tunes can only be used with PYTHIA 6, not with PYTHIA
8. Note: this report was updated in March 2011 with a new set of variations,
collectively labeled "Perugia 2011", that are optimized for matching
applications and which also take into account some lessons from the early LHC
data. In order not to break the original text, these are described separately
in Appendix B. Note 2: a subsequent "Perugia 2012" update is described in
Appendix C.
| [
{
"created": "Wed, 19 May 2010 14:41:34 GMT",
"version": "v1"
},
{
"created": "Wed, 1 Sep 2010 13:38:27 GMT",
"version": "v2"
},
{
"created": "Wed, 12 Jan 2011 11:07:28 GMT",
"version": "v3"
},
{
"created": "Thu, 5 May 2011 07:23:25 GMT",
"version": "v4"
},
{
"created": "Tue, 15 Apr 2014 16:03:10 GMT",
"version": "v5"
}
] | 2015-03-17 | [
[
"Skands",
"Peter Zeiler",
""
]
] | We present 9 new tunes of the pT-ordered shower and underlying-event model in PYTHIA 6.4. These "Perugia" tunes update and supersede the older "S0" family. The data sets used to constrain the models include hadronic Z0 decays at LEP, Tevatron minimum-bias data at 630, 1800, and 1960 GeV, Tevatron Drell-Yan data at 1800 and 1960 GeV, and SPS min-bias data at 200, 546, and 900 GeV. In addition to the central parameter set, called "Perugia 0", we introduce a set of 8 related "Perugia Variations" that attempt to systematically explore soft, hard, parton density, and colour structure variations in the theoretical parameters. Based on these variations, a best-guess prediction of the charged track multiplicity in inelastic, nondiffractive minimum-bias events at the LHC is made. Note that these tunes can only be used with PYTHIA 6, not with PYTHIA 8. Note: this report was updated in March 2011 with a new set of variations, collectively labeled "Perugia 2011", that are optimized for matching applications and which also take into account some lessons from the early LHC data. In order not to break the original text, these are described separately in Appendix B. Note 2: a subsequent "Perugia 2012" update is described in Appendix C. |
1805.04415 | Heerak Banerjee | Heerak Banerjee, Pritibhajan Byakti and Sourov Roy | Supersymmetric gauged U(1)$_{L_{\mu}-L_{\tau}}$ model for neutrinos and
the muon $(g-2)$ anomaly | v2: 25 pages, 9 figures. Discussion on charged
lepton-flavor-violating processes $l_j\rightarrow l_i\gamma$ added in the
text. Appendix C added on the same. References added. Published Version | Phys. Rev. D 98, 075022 (2018) | 10.1103/PhysRevD.98.075022 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The gauged $U(1)_{L_{\mu}-L_{\tau}}$ model can provide for additional
contributions to the muon anomalous magnetic moment by means of a loop
involving the $Z^{\prime}$ gauge boson. However, the parameter space of such
models is severely constrained if one combines the latest muon $(g-2)$ data
with various neutrino experiments, such as neutrino trident production, $\nu
-e$ and $\nu -q$ elastic scattering, etc. In a supersymmetric
$U(1)_{L_{\mu}-L_{\tau}}$ model, a larger region of parameter space opens up,
thus enabling one to explore otherwise forbidden regions of parameter space in
nonsupersymmetric models involving the new gauge coupling ($g_X$) and the mass
of the $Z^\prime$ gauge boson ($M_{Z^{\prime}}$) . We show that the minimal
model with the minimal supersymmetric Standard Model (MSSM) field content is
strongly disfavored from $Z$-boson decay and neutrino data. We also show that
the nonminimal model with two extra singlet superfields can lead to correct
neutrino masses and mixing involving both tree-level and one-loop
contributions. We find that, in this model, both muon $(g-2)$ and neutrino data
may be simultaneously explained in a parameter region consistent with
experimental observations. In addition, we observe that the muon $(g-2)$
anomaly can be accommodated even with higher values of electroweak sparticle
masses compared to the MSSM. Charged lepton-flavor-violating processes (like
$\mu\rightarrow e\gamma$, $\tau\rightarrow \mu\gamma$, etc.) may have
potentially large branching ratios in this scenario. Depending on the magnitude
of the supersymmetry contribution to these processes, they may constrain
hitherto unconstrained regions of the $M_{Z^{\prime}}-g_X$ parameter space.
However, we find that these branching fractions never exceed their upper bounds
in a region where both muon $(g-2)$ and neutrino oscillation data can be
simultaneously accommodated.
| [
{
"created": "Fri, 11 May 2018 14:21:51 GMT",
"version": "v1"
},
{
"created": "Mon, 5 Nov 2018 13:51:23 GMT",
"version": "v2"
}
] | 2018-11-06 | [
[
"Banerjee",
"Heerak",
""
],
[
"Byakti",
"Pritibhajan",
""
],
[
"Roy",
"Sourov",
""
]
] | The gauged $U(1)_{L_{\mu}-L_{\tau}}$ model can provide for additional contributions to the muon anomalous magnetic moment by means of a loop involving the $Z^{\prime}$ gauge boson. However, the parameter space of such models is severely constrained if one combines the latest muon $(g-2)$ data with various neutrino experiments, such as neutrino trident production, $\nu -e$ and $\nu -q$ elastic scattering, etc. In a supersymmetric $U(1)_{L_{\mu}-L_{\tau}}$ model, a larger region of parameter space opens up, thus enabling one to explore otherwise forbidden regions of parameter space in nonsupersymmetric models involving the new gauge coupling ($g_X$) and the mass of the $Z^\prime$ gauge boson ($M_{Z^{\prime}}$) . We show that the minimal model with the minimal supersymmetric Standard Model (MSSM) field content is strongly disfavored from $Z$-boson decay and neutrino data. We also show that the nonminimal model with two extra singlet superfields can lead to correct neutrino masses and mixing involving both tree-level and one-loop contributions. We find that, in this model, both muon $(g-2)$ and neutrino data may be simultaneously explained in a parameter region consistent with experimental observations. In addition, we observe that the muon $(g-2)$ anomaly can be accommodated even with higher values of electroweak sparticle masses compared to the MSSM. Charged lepton-flavor-violating processes (like $\mu\rightarrow e\gamma$, $\tau\rightarrow \mu\gamma$, etc.) may have potentially large branching ratios in this scenario. Depending on the magnitude of the supersymmetry contribution to these processes, they may constrain hitherto unconstrained regions of the $M_{Z^{\prime}}-g_X$ parameter space. However, we find that these branching fractions never exceed their upper bounds in a region where both muon $(g-2)$ and neutrino oscillation data can be simultaneously accommodated. |
hep-ph/9905428 | Paul Langacker | Paul Langacker | Theoretical Summary, Electroweak Physics | Talk presented at the 17^{th} International Workshop on Weak
Interactions and Neutrinos (WIN 99), Cape Town, South Africa, January 24-30,
1999. 8 pages | null | null | null | hep-ph | null | Aspects of theoretical electroweak physics are summarized, including the
status of electroweak radiative corrections, the hadronic contribution to the
running of alpha, global fits to precision data and their implication for
testing the standard model and constraining new physics, and electroweak
baryogenesis.
| [
{
"created": "Thu, 20 May 1999 21:53:56 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Langacker",
"Paul",
""
]
] | Aspects of theoretical electroweak physics are summarized, including the status of electroweak radiative corrections, the hadronic contribution to the running of alpha, global fits to precision data and their implication for testing the standard model and constraining new physics, and electroweak baryogenesis. |
hep-ph/0402167 | Igor O. Cherednikov | Igor O. Cherednikov | High energy behavior of quark elastic form factors within the Wilson
integral approach: perturbative and nonperturbative contributions | Talk at the XVII International Workshop QFTHEP-2003, Samara-Saratov,
Russia, 4-11 Sept 2003; to be published in the Proceedings. 4 pp., REVTeX | null | null | null | hep-ph | null | The Wilson contour integral approach is applied to resum the soft gluon
radiative correctins to the quark form factors in the Sudakov regime. The
one-loop order results for the quark-photon (color singlet form factor) and
quark-gluon (color non-singlet form factor) vertices are presented. The
explicit expressions for the vacuum averaged contour integrals in $g^2$
accuracy are derived for an arbitrary gauge field. The corresponding one-loop
cusp anomalous dimensions are found in the case of perturbative gluon field in
arbitrary covariant gauge. It is shown that the gauge dependence drops out from
the leading high energy behavior.
| [
{
"created": "Tue, 17 Feb 2004 10:48:45 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Cherednikov",
"Igor O.",
""
]
] | The Wilson contour integral approach is applied to resum the soft gluon radiative correctins to the quark form factors in the Sudakov regime. The one-loop order results for the quark-photon (color singlet form factor) and quark-gluon (color non-singlet form factor) vertices are presented. The explicit expressions for the vacuum averaged contour integrals in $g^2$ accuracy are derived for an arbitrary gauge field. The corresponding one-loop cusp anomalous dimensions are found in the case of perturbative gluon field in arbitrary covariant gauge. It is shown that the gauge dependence drops out from the leading high energy behavior. |
1007.2923 | Anindya Datta | Debajyoti Choudhury, Anindya Datta, Anirban Kundu | Mutual consistency of the MINOS and MiniBooNE Antineutrino Results and
Possible CPT Violation | 7 pages, 3 fugures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Discussing the recent MINOS data on muon anti-neutrino disappearance and the
MiniBooNE data on muon anti-neutrino to electron anti-neutrino oscillation, we
show that the while the respective best fits are inconsistent with each other,
significant overlap of allowed regions does exist. Assuming only three neutrino
species, the data indicates a discrepancy of mass levels and mixing angles
between the neutrino and the antineutrino sectors. We show that the existing
data can be reconciled with a model of explicit CPT violation in the neutrino
sector and estimate the magnitude of the required violation.
| [
{
"created": "Sat, 17 Jul 2010 12:20:23 GMT",
"version": "v1"
}
] | 2010-07-20 | [
[
"Choudhury",
"Debajyoti",
""
],
[
"Datta",
"Anindya",
""
],
[
"Kundu",
"Anirban",
""
]
] | Discussing the recent MINOS data on muon anti-neutrino disappearance and the MiniBooNE data on muon anti-neutrino to electron anti-neutrino oscillation, we show that the while the respective best fits are inconsistent with each other, significant overlap of allowed regions does exist. Assuming only three neutrino species, the data indicates a discrepancy of mass levels and mixing angles between the neutrino and the antineutrino sectors. We show that the existing data can be reconciled with a model of explicit CPT violation in the neutrino sector and estimate the magnitude of the required violation. |
hep-ph/9902375 | Gregory Korchemsky | V.M. Braun, S.E. Derkachov, G.P. Korchemsky and A.N. Manashov | Baryon Distribution Amplitudes in QCD | 75 pages, LaTeX style, 18 figures embedded with epsf.sty | Nucl.Phys. B553 (1999) 355-426 | 10.1016/S0550-3213(99)00265-5 | LPT-Orsay-98-83, NORDITA-99-11-HE, SPbU-IP-99-04 | hep-ph nlin.SI solv-int | null | We develop a new theoretical framework for the description of leading twist
light-cone baryon distribution amplitudes which is based on integrability of
the helicity $\lambda=3/2$ evolution equation to leading logarithmic accuracy.
A physical interpretation is that one can identify a new `hidden' quantum
number which distinguishes components in the $\lambda=3/2$ distribution
amplitudes with different scale dependence. The solution of the corresponding
evolution equation is reduced to a simple three-term recurrence relation. The
exact analytic solution is found for the component with the lowest anomalous
dimension for all moments $N$, and the WKB-type expansion is constructed for
other levels, which becomes asymptotically exact at large $N$. Evolution
equations for the $\lambda=1/2$ distribution amplitudes (e.g. for the nucleon)
are studied as well. We find that the two lowest anomalous dimensions for the
$\lambda=1/2$ operators (one for each parity) are separated from the rest of
the spectrum by a finite `mass gap'. These special states can be interpreted as
scalar diquarks.
| [
{
"created": "Wed, 17 Feb 1999 14:31:27 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Braun",
"V. M.",
""
],
[
"Derkachov",
"S. E.",
""
],
[
"Korchemsky",
"G. P.",
""
],
[
"Manashov",
"A. N.",
""
]
] | We develop a new theoretical framework for the description of leading twist light-cone baryon distribution amplitudes which is based on integrability of the helicity $\lambda=3/2$ evolution equation to leading logarithmic accuracy. A physical interpretation is that one can identify a new `hidden' quantum number which distinguishes components in the $\lambda=3/2$ distribution amplitudes with different scale dependence. The solution of the corresponding evolution equation is reduced to a simple three-term recurrence relation. The exact analytic solution is found for the component with the lowest anomalous dimension for all moments $N$, and the WKB-type expansion is constructed for other levels, which becomes asymptotically exact at large $N$. Evolution equations for the $\lambda=1/2$ distribution amplitudes (e.g. for the nucleon) are studied as well. We find that the two lowest anomalous dimensions for the $\lambda=1/2$ operators (one for each parity) are separated from the rest of the spectrum by a finite `mass gap'. These special states can be interpreted as scalar diquarks. |
1605.04474 | Fred Jegerlehner | M. Benayoun, P. David, L. DelBuono, F. Jegerlehner | A BHLS model based moment analysis of muon g-2, and its use for lattice
QCD evaluations of $a_\mu^{\rm had}$ | 45 pqges, 15 figures | null | null | LPNHE/2016-01, DESY 16-081 | hep-ph hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present an up-to-date analysis of muon $g-2$ evaluations in terms of
Mellin-Barnes moments as they might be useful for lattice QCD calculations of
$a_\mu$. The moments up to 4th order are evaluated directly in terms of
$e^+e^-$--annihilation data and improved within the Hidden Local Symmetry (HLS)
Model, supplied with appropriate symmetry breaking mechanisms. The model
provides a reliable Effective Lagrangian (BHLS) estimate of the two-body
channels plus the $\pi\pi\pi$ channel up to 1.05~GeV, just including the $\phi$
resonance. The HLS piece accounts for 80\% of the contribution to $a_\mu$. The
missing pieces are evaluated in the standard way directly in terms of the data.
We find that the moment expansion converges well in terms of a few moments. The
two types of moments which show up in the Mellin-Barnes representation are
calculated in terms of hadronic cross--section data in the timelike region and
in terms of the hadronic vacuum polarization (HVP) function in the spacelike
region which is accessible to lattice QCD (LQCD). In the Euclidean the first
type of moments are the usual Taylor coefficients of the HVP and we show that
the second type of moments may be obtained as integrals over the appropriately
Taylor truncated HVP function. Specific results for the isovector part of
$a_\mu^{\rm had}$ are determined by means of HLS model predictions in close
relation to $\tau$--decay spectra.
| [
{
"created": "Sat, 14 May 2016 22:00:13 GMT",
"version": "v1"
}
] | 2016-05-20 | [
[
"Benayoun",
"M.",
""
],
[
"David",
"P.",
""
],
[
"DelBuono",
"L.",
""
],
[
"Jegerlehner",
"F.",
""
]
] | We present an up-to-date analysis of muon $g-2$ evaluations in terms of Mellin-Barnes moments as they might be useful for lattice QCD calculations of $a_\mu$. The moments up to 4th order are evaluated directly in terms of $e^+e^-$--annihilation data and improved within the Hidden Local Symmetry (HLS) Model, supplied with appropriate symmetry breaking mechanisms. The model provides a reliable Effective Lagrangian (BHLS) estimate of the two-body channels plus the $\pi\pi\pi$ channel up to 1.05~GeV, just including the $\phi$ resonance. The HLS piece accounts for 80\% of the contribution to $a_\mu$. The missing pieces are evaluated in the standard way directly in terms of the data. We find that the moment expansion converges well in terms of a few moments. The two types of moments which show up in the Mellin-Barnes representation are calculated in terms of hadronic cross--section data in the timelike region and in terms of the hadronic vacuum polarization (HVP) function in the spacelike region which is accessible to lattice QCD (LQCD). In the Euclidean the first type of moments are the usual Taylor coefficients of the HVP and we show that the second type of moments may be obtained as integrals over the appropriately Taylor truncated HVP function. Specific results for the isovector part of $a_\mu^{\rm had}$ are determined by means of HLS model predictions in close relation to $\tau$--decay spectra. |
1004.3266 | Wayne W. Repko | Duane A. Dicus, Shao-Feng Ge and Wayne W. Repko | Neutrino mixing with broken $S_3$ symmetry | Final version. Published in Phys. Rev. D 82, 033005 (2010) | Phys.Rev.D82:033005,2010 | 10.1103/PhysRevD.82.033005 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We explore the consequences of assuming that the neutrino mass matrix is a
linear combination of the matrices of a three dimensional representation of the
group $S_3$ and that it has one zero mass eigenvalue. When implemented, these
two assumptions allow us to express the transformation matrix relating the mass
eigenstates to the flavor eigenstates in terms of a single parameter which we
fit to the available data.
| [
{
"created": "Mon, 19 Apr 2010 18:04:57 GMT",
"version": "v1"
},
{
"created": "Wed, 11 Aug 2010 17:56:01 GMT",
"version": "v2"
}
] | 2014-11-20 | [
[
"Dicus",
"Duane A.",
""
],
[
"Ge",
"Shao-Feng",
""
],
[
"Repko",
"Wayne W.",
""
]
] | We explore the consequences of assuming that the neutrino mass matrix is a linear combination of the matrices of a three dimensional representation of the group $S_3$ and that it has one zero mass eigenvalue. When implemented, these two assumptions allow us to express the transformation matrix relating the mass eigenstates to the flavor eigenstates in terms of a single parameter which we fit to the available data. |
1810.02973 | Dorota Strozik-Kotlorz | D. Kotlorz and S. V. Mikhailov | Optimized determination of the polarized Bjorken sum rule in pQCD | 14 pages, 3 figures | Phys. Rev. D 100, 056007 (2019) | 10.1103/PhysRevD.100.056007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the method of numerical optimization for the perturbative series
using the renormalization group in quantum chromodynamics. We apply our
approach to the perturbation series in $\alpha_s$ for the coefficient function
$C_\text{Bjp}(\alpha_s)$ of the Bjorken sum rule for the polarized deep
inelastic lepton-hadron scattering. We optimize the Bjorken sum rule value,
$\Gamma_1^\text{p-n}$, at the COMPASS, SLAC and JLab kinematics and compare the
obtained results with the experimental measurements and also with the truncated
Bjorken sum rule predictions.
| [
{
"created": "Sat, 6 Oct 2018 10:14:11 GMT",
"version": "v1"
},
{
"created": "Mon, 16 Sep 2019 18:10:06 GMT",
"version": "v2"
}
] | 2019-09-19 | [
[
"Kotlorz",
"D.",
""
],
[
"Mikhailov",
"S. V.",
""
]
] | We present the method of numerical optimization for the perturbative series using the renormalization group in quantum chromodynamics. We apply our approach to the perturbation series in $\alpha_s$ for the coefficient function $C_\text{Bjp}(\alpha_s)$ of the Bjorken sum rule for the polarized deep inelastic lepton-hadron scattering. We optimize the Bjorken sum rule value, $\Gamma_1^\text{p-n}$, at the COMPASS, SLAC and JLab kinematics and compare the obtained results with the experimental measurements and also with the truncated Bjorken sum rule predictions. |
2002.12245 | Liliana Apolin\'ario | Liliana Apolin\'ario | Road map to extracting medium properties: an overview | [v1:] 8 pages, 5 figures, Quark Matter 2019 Proceedings; [v2:]
Reference added; Typos corrected | null | 10.1016/j.nuclphysa.2020.121983 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this manuscript, it is presented an overview of the Quark-Gluon Plasma
properties measured, so far, using hard probes. We will focus on both
quantitative and qualitative properties that have been (or are about to be)
measured, making a link between the theoretical description and experimental
results. Throughout the manuscript, highlights to some of the conferences'
results will be given, but without an extensive overview. A personal opinion of
the most important developments and critical problems that need more work in
the future is presented at the end.
| [
{
"created": "Thu, 27 Feb 2020 16:43:10 GMT",
"version": "v1"
},
{
"created": "Wed, 8 Jul 2020 16:08:54 GMT",
"version": "v2"
}
] | 2021-02-03 | [
[
"Apolinário",
"Liliana",
""
]
] | In this manuscript, it is presented an overview of the Quark-Gluon Plasma properties measured, so far, using hard probes. We will focus on both quantitative and qualitative properties that have been (or are about to be) measured, making a link between the theoretical description and experimental results. Throughout the manuscript, highlights to some of the conferences' results will be given, but without an extensive overview. A personal opinion of the most important developments and critical problems that need more work in the future is presented at the end. |
1808.04982 | Eugene Levin | E. Gotsman (Tel Aviv U.) and E. Levin (Tel Aviv U./UTFSM) | Energy evolution and the Bose-Einstein enhancement for double parton
densities | 19pp. 7 figures in pdf files | Phys. Rev. D 99, 054015 (2019) | 10.1103/PhysRevD.99.054015 | TAUP 3032/18 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper we found that the Bose-Einstein enhancement generates the
strong correlations, which increase with energy in the BFKL evolution. This
increase leads to the double parton densities ( $\Phi$), that are much larger
than the product of the single parton densities ($\phi$). However, numerically,
it turns out that the ratio $\Phi/\phi^2 \propto \Lb 1/x\Rb^{\delta_2}$ with
$\delta_2 \sim \bas/\Lb N^2_c - 1\Rb^{2/3}\,\,\ll\,\,1$ and we do not expect a
large correction for the accessible range of energies. However, for $N_c=3$ it
tuns out that $\delta_2 = 0.07 \Delta_{\rm BFKL}$ where $\Delta_{\rm BFKL}$ is
the intercept of the BFKL Pomeron and we can anticipate an substantial increase
for the range of rapidities $Y \sim 20$.It is shown that all $1/(N^2_c -1)$
corrections to the double parton densities stem from the Bose-Einstein
enhancement.
| [
{
"created": "Wed, 15 Aug 2018 06:41:32 GMT",
"version": "v1"
},
{
"created": "Sun, 19 Aug 2018 07:19:09 GMT",
"version": "v2"
},
{
"created": "Tue, 12 Mar 2019 10:10:22 GMT",
"version": "v3"
}
] | 2019-03-27 | [
[
"Gotsman",
"E.",
"",
"Tel Aviv U."
],
[
"Levin",
"E.",
"",
"Tel Aviv U./UTFSM"
]
] | In this paper we found that the Bose-Einstein enhancement generates the strong correlations, which increase with energy in the BFKL evolution. This increase leads to the double parton densities ( $\Phi$), that are much larger than the product of the single parton densities ($\phi$). However, numerically, it turns out that the ratio $\Phi/\phi^2 \propto \Lb 1/x\Rb^{\delta_2}$ with $\delta_2 \sim \bas/\Lb N^2_c - 1\Rb^{2/3}\,\,\ll\,\,1$ and we do not expect a large correction for the accessible range of energies. However, for $N_c=3$ it tuns out that $\delta_2 = 0.07 \Delta_{\rm BFKL}$ where $\Delta_{\rm BFKL}$ is the intercept of the BFKL Pomeron and we can anticipate an substantial increase for the range of rapidities $Y \sim 20$.It is shown that all $1/(N^2_c -1)$ corrections to the double parton densities stem from the Bose-Einstein enhancement. |
hep-ph/0405231 | Steven Gubser | Steven S. Gubser and Justin Khoury | Scalar self-interactions loosen constraints from fifth force searches | 19 pages, 6 figures. v2: Revised figures and added discussion on
Colorado and Stanford experiments | Phys.Rev. D70 (2004) 104001 | 10.1103/PhysRevD.70.104001 | PUPT-2119 | hep-ph astro-ph hep-th | null | The mass of a scalar field mediating a fifth force is tightly constrained by
experiments. We show, however, that adding a quartic self-interaction for such
a scalar makes most tests much less constraining: the non-linear equation of
motion masks the coupling of the scalar to matter through the chameleon
mechanism. We discuss consequences for fifth force experiments. In particular,
we find that, with quartic coupling of order unity, a gravitational strength
interaction with matter is allowed by current constraints. We show that our
chameleon scalar field results in experimental signatures that could be
detected through modest improvements of current laboratory set-ups.
| [
{
"created": "Mon, 24 May 2004 14:58:30 GMT",
"version": "v1"
},
{
"created": "Tue, 10 Aug 2004 16:29:22 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Gubser",
"Steven S.",
""
],
[
"Khoury",
"Justin",
""
]
] | The mass of a scalar field mediating a fifth force is tightly constrained by experiments. We show, however, that adding a quartic self-interaction for such a scalar makes most tests much less constraining: the non-linear equation of motion masks the coupling of the scalar to matter through the chameleon mechanism. We discuss consequences for fifth force experiments. In particular, we find that, with quartic coupling of order unity, a gravitational strength interaction with matter is allowed by current constraints. We show that our chameleon scalar field results in experimental signatures that could be detected through modest improvements of current laboratory set-ups. |
hep-ph/9707426 | Michael Rueter | Michael Rueter, H.G. Dosch (IHEP, Univ. Heidelberg) | Diffractive color-dipole nucleon scattering | 7 pages, 5 eps-figures, uses epsf | Phys.Rev.D57:4097-4100,1998 | 10.1103/PhysRevD.57.4097 | HD-THEP-97-34 | hep-ph | null | We determine the diffractive scattering amplitude of a color-dipole on a
nucleon using a non-perturbative model of QCD which contains only parameters
taken from low-energy physics. This allows to relate specific features of the
confinement mechanisms with diffractive electro-production processes and
structure functions. The agreement with phenomenological data is satisfactory.
| [
{
"created": "Tue, 22 Jul 1997 15:04:29 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Rueter",
"Michael",
"",
"IHEP, Univ. Heidelberg"
],
[
"Dosch",
"H. G.",
"",
"IHEP, Univ. Heidelberg"
]
] | We determine the diffractive scattering amplitude of a color-dipole on a nucleon using a non-perturbative model of QCD which contains only parameters taken from low-energy physics. This allows to relate specific features of the confinement mechanisms with diffractive electro-production processes and structure functions. The agreement with phenomenological data is satisfactory. |
2211.06847 | Tong Li | Tong Li, Rui-Jia Zhang, Chang-Jie Dai | Solutions to axion electromagnetodynamics and new search strategies of
sub-$\mu$eV axion | 18 pages, 5 figures. Version accepted for publication in JHEP | null | 10.1007/JHEP03(2023)088 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | The Witten effect implies the electromagnetic interactions between axions and
magnetic monopoles. Based on the quantum electromagnetodynamics, a generic
low-energy axion-photon effective field theory was built by introducing two
four-potentials ($A^\mu$ and $B^\mu$) to describe a photon. More anomalous
axion-photon interactions and couplings ($g_{aAA}$, $g_{aBB}$ and $g_{aAB}$)
arise in contrary to the ordinary axion coupling
$g_{a\gamma\gamma}aF^{\mu\nu}\tilde{F}_{\mu\nu}$. As a consequence, the
conventional axion Maxwell equations are further modified. We properly solve
the new axion-modified Maxwell equations and obtain the axion-induced
electromagnetic fields given a static electric or magnetic field. It turns out
that the dominant couplings $g_{aAB}$ and $g_{aBB}$ can be probed in the
presence of external magnetic field and electric field, respectively. The
induced oscillating magnetic fields are always suppressed compared with the
electric fields for the axions with large Compton wavelengths. This is contrary
to the situation in conventional experiments searching for the oscillating
magnetic fields induced by sub-$\mu$eV axions. Thus, we propose new strategies
to measure the new couplings for sub-$\mu$eV axion in haloscope experiments.
| [
{
"created": "Sun, 13 Nov 2022 08:31:26 GMT",
"version": "v1"
},
{
"created": "Wed, 1 Mar 2023 13:56:50 GMT",
"version": "v2"
}
] | 2023-04-05 | [
[
"Li",
"Tong",
""
],
[
"Zhang",
"Rui-Jia",
""
],
[
"Dai",
"Chang-Jie",
""
]
] | The Witten effect implies the electromagnetic interactions between axions and magnetic monopoles. Based on the quantum electromagnetodynamics, a generic low-energy axion-photon effective field theory was built by introducing two four-potentials ($A^\mu$ and $B^\mu$) to describe a photon. More anomalous axion-photon interactions and couplings ($g_{aAA}$, $g_{aBB}$ and $g_{aAB}$) arise in contrary to the ordinary axion coupling $g_{a\gamma\gamma}aF^{\mu\nu}\tilde{F}_{\mu\nu}$. As a consequence, the conventional axion Maxwell equations are further modified. We properly solve the new axion-modified Maxwell equations and obtain the axion-induced electromagnetic fields given a static electric or magnetic field. It turns out that the dominant couplings $g_{aAB}$ and $g_{aBB}$ can be probed in the presence of external magnetic field and electric field, respectively. The induced oscillating magnetic fields are always suppressed compared with the electric fields for the axions with large Compton wavelengths. This is contrary to the situation in conventional experiments searching for the oscillating magnetic fields induced by sub-$\mu$eV axions. Thus, we propose new strategies to measure the new couplings for sub-$\mu$eV axion in haloscope experiments. |
hep-ph/9703284 | Timo van Ritbergen | J.A.M. Vermaseren, S.A. Larin, T. van Ritbergen | The 4-loop quark mass anomalous dimension and the invariant quark mass | 11 pages, Latex | Phys.Lett. B405 (1997) 327-333 | 10.1016/S0370-2693(97)00660-6 | UM-TH-97-03, NIKHEF-97-012 | hep-ph | null | We present the analytical calculation of the four-loop quark mass anomalous
dimension in Quantum Chromodynamics within the minimal subtraction scheme. On
the basis of this result we find that the so-called invariant quark mass is a
very good reference mass for the accurate evolution of the running MS-bar quark
mass in phenomenological applications. We also obtain for the first time a
complete 4-th order perturbative QCD expression for a physical quantity, the
total Higgs boson decay rate into hadrons, and analyze the infrared fixed point
for this case.
| [
{
"created": "Mon, 10 Mar 1997 18:06:50 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Vermaseren",
"J. A. M.",
""
],
[
"Larin",
"S. A.",
""
],
[
"van Ritbergen",
"T.",
""
]
] | We present the analytical calculation of the four-loop quark mass anomalous dimension in Quantum Chromodynamics within the minimal subtraction scheme. On the basis of this result we find that the so-called invariant quark mass is a very good reference mass for the accurate evolution of the running MS-bar quark mass in phenomenological applications. We also obtain for the first time a complete 4-th order perturbative QCD expression for a physical quantity, the total Higgs boson decay rate into hadrons, and analyze the infrared fixed point for this case. |
1106.5157 | Bruno Os\'orio Rodrigues | B. Os\'orio Rodrigues, M.E. Bracco and M. Chiapparini | An inspection on the Borel masses relation used in QCD sum rules | 6 pages, 2 figures, Prepared for 11th Hadron Physics | AIP Conf.Proc. 1296 (2010) 302-305 | 10.1063/1.3523191 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work, we studied the Borel masses relation used in QCDSR
calculations. These masses are the parameters of the Borel transform used when
the three point function is calculated. We analised an usual and a more general
linear relations. We concluded that a general linear relation between these
masses provides the best results regarding the standard deviation.
| [
{
"created": "Sat, 25 Jun 2011 18:19:12 GMT",
"version": "v1"
},
{
"created": "Tue, 28 Jun 2011 13:10:45 GMT",
"version": "v2"
}
] | 2011-06-29 | [
[
"Rodrigues",
"B. Osório",
""
],
[
"Bracco",
"M. E.",
""
],
[
"Chiapparini",
"M.",
""
]
] | In this work, we studied the Borel masses relation used in QCDSR calculations. These masses are the parameters of the Borel transform used when the three point function is calculated. We analised an usual and a more general linear relations. We concluded that a general linear relation between these masses provides the best results regarding the standard deviation. |
hep-ph/0212034 | Taekoon Lee | Taekoon Lee | Direct resummation of the leading renormalons in inclusive semileptonic
B decay | 10 pages,3 figures, version to appear in Phys. Lett. B | Phys.Lett. B563 (2003) 93 | 10.1016/S0370-2693(03)00591-4 | null | hep-ph | null | We present a Borel resummation method for the QCD corrections in inclusive,
charmless, semileptonic B meson decay. The renormalon contributions are
resummed to all orders by employing a bilocal expansion of the Borel transform
that accurately accounts for the first infrared renormalons in the Borel plane.
The renormalons in the pole mass and the QCD expansion are resummed separately,
and a precise relation is obtained between a properly defined pole mass and the
${\bar {\rm MS}}$ mass. The inclusive decay rate is calculated to three loop
order using an estimate of the yet unknown NNLO coefficient.
| [
{
"created": "Tue, 3 Dec 2002 07:59:11 GMT",
"version": "v1"
},
{
"created": "Tue, 25 Feb 2003 01:08:02 GMT",
"version": "v2"
},
{
"created": "Tue, 6 May 2003 02:49:52 GMT",
"version": "v3"
}
] | 2009-11-07 | [
[
"Lee",
"Taekoon",
""
]
] | We present a Borel resummation method for the QCD corrections in inclusive, charmless, semileptonic B meson decay. The renormalon contributions are resummed to all orders by employing a bilocal expansion of the Borel transform that accurately accounts for the first infrared renormalons in the Borel plane. The renormalons in the pole mass and the QCD expansion are resummed separately, and a precise relation is obtained between a properly defined pole mass and the ${\bar {\rm MS}}$ mass. The inclusive decay rate is calculated to three loop order using an estimate of the yet unknown NNLO coefficient. |
2205.02810 | Kanat Nurlan | Mikhail K. Volkov, Aleksey A. Pivovarov, Kanat Nurlan | The decays $\tau \to a_{1} \pi \nu_\tau$, $\tau \to K_{1} \pi \nu_\tau$
and $\tau \to K_{1} K \nu_\tau$ in the extended $U(3)\times U(3)$ chiral NJL
model | 8 pages, 4 figures | null | 10.1142/S0217732322501188 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The branching fractions of the decays $\tau \to a_{1} \pi \nu_\tau$, $\tau
\to K_{1} \pi \nu_\tau$ and $\tau \to K_{1} K \nu_\tau$ are calculated in the
framework of the extended $U(3)\times U(3)$ chiral Nambu--Jona-Lasinio model.
There are no experimental data for these decays in the present time, thus the
obtained results are considered as predictions. The comparison of these results
to the theoretical results of other authors is carried out.
| [
{
"created": "Thu, 5 May 2022 17:41:20 GMT",
"version": "v1"
}
] | 2022-09-07 | [
[
"Volkov",
"Mikhail K.",
""
],
[
"Pivovarov",
"Aleksey A.",
""
],
[
"Nurlan",
"Kanat",
""
]
] | The branching fractions of the decays $\tau \to a_{1} \pi \nu_\tau$, $\tau \to K_{1} \pi \nu_\tau$ and $\tau \to K_{1} K \nu_\tau$ are calculated in the framework of the extended $U(3)\times U(3)$ chiral Nambu--Jona-Lasinio model. There are no experimental data for these decays in the present time, thus the obtained results are considered as predictions. The comparison of these results to the theoretical results of other authors is carried out. |
hep-ph/0605282 | Arif Shoshi | Arif I. Shoshi (Bielefeld University), Bo-Wen Xiao (Columbia
University) | Diffractive dissociation including pomeron loops in zero transverse
dimensions | 14 pages, 5 figures; numerous explanations added, matches the
published version | Phys.Rev.D75:054002,2007 | 10.1103/PhysRevD.75.054002 | BI-TP 2006/20, CU-TP-1148 | hep-ph | null | We have recently studied the QCD pomeron loop evolution equations in zero
transverse dimensions [Shoshi:2005pf]. Using the techniques developed in
[Shoshi:2005pf] together with the AGK cutting rules, we present a calculation
of single, double and central diffractive cross sections (for large diffractive
masses and large rapidity gaps) in zero transverse dimensions in which all
dominant pomeron loop graphs are consistently summed. We find that the
diffractive cross sections unitarise at asymptotic energies and that they are
suppressed by powers of alpha_s. Our calculation is expected to expose some of
the diffractive physics in hadron-hadron collisions at high energy.
| [
{
"created": "Fri, 26 May 2006 12:31:44 GMT",
"version": "v1"
},
{
"created": "Sat, 16 Sep 2006 14:32:50 GMT",
"version": "v2"
},
{
"created": "Sat, 10 Feb 2007 02:29:58 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Shoshi",
"Arif I.",
"",
"Bielefeld University"
],
[
"Xiao",
"Bo-Wen",
"",
"Columbia\n University"
]
] | We have recently studied the QCD pomeron loop evolution equations in zero transverse dimensions [Shoshi:2005pf]. Using the techniques developed in [Shoshi:2005pf] together with the AGK cutting rules, we present a calculation of single, double and central diffractive cross sections (for large diffractive masses and large rapidity gaps) in zero transverse dimensions in which all dominant pomeron loop graphs are consistently summed. We find that the diffractive cross sections unitarise at asymptotic energies and that they are suppressed by powers of alpha_s. Our calculation is expected to expose some of the diffractive physics in hadron-hadron collisions at high energy. |
hep-ph/9408216 | Wolfgang Moedritsch | W.Kummer and W.Moedritsch | Rigorous QCD-Potential for the $t\bar{t}$-System at Threshold | 36 pages (mailer uncorrupted version), TUW-94-14 | Z.Phys.C66:225-240,1995 | 10.1007/BF01496596 | null | hep-ph | null | Recent evidence for the top mass in the region of 160 $GeV$ for the first
time provides an opportunity to use the full power of relativistic quantum
field theoretical methods, available also for weakly bound systems. Because of
the large decay width $\G$ of the top quark individual energy-levels in
"toponium" will be unobservable. However, the potential for the $t\bar{t}$
system, based on a systematic expansion in powers of the strong coupling
constant $\a_s$ can be rigorously derived from QCD and plays a central role in
the threshold region. It is essential that the neglect of nonperturbative
(confining) effects is fully justified here for the first time to a large
accuracy, also just {\it because} of the large $\G$. The different
contributions to that potential are computed from real level corrections near
the bound state poles of the $t\bar{t}$-system which for $\G \ne 0$ move into
the unphysical sheet of the complex energy plane. Thus, in order to obtain the
different contributions to that potential we may use the level corrections at
that (complex) pole. Within the relevant level shifts we especially emphasize
the corrections of order $O(\a_s^4 m_t)$ and numerically comparable ones to
that order also from electroweak interactions which may become important as
well.
| [
{
"created": "Tue, 2 Aug 1994 18:23:51 GMT",
"version": "v1"
},
{
"created": "Thu, 4 Aug 1994 12:03:46 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Kummer",
"W.",
""
],
[
"Moedritsch",
"W.",
""
]
] | Recent evidence for the top mass in the region of 160 $GeV$ for the first time provides an opportunity to use the full power of relativistic quantum field theoretical methods, available also for weakly bound systems. Because of the large decay width $\G$ of the top quark individual energy-levels in "toponium" will be unobservable. However, the potential for the $t\bar{t}$ system, based on a systematic expansion in powers of the strong coupling constant $\a_s$ can be rigorously derived from QCD and plays a central role in the threshold region. It is essential that the neglect of nonperturbative (confining) effects is fully justified here for the first time to a large accuracy, also just {\it because} of the large $\G$. The different contributions to that potential are computed from real level corrections near the bound state poles of the $t\bar{t}$-system which for $\G \ne 0$ move into the unphysical sheet of the complex energy plane. Thus, in order to obtain the different contributions to that potential we may use the level corrections at that (complex) pole. Within the relevant level shifts we especially emphasize the corrections of order $O(\a_s^4 m_t)$ and numerically comparable ones to that order also from electroweak interactions which may become important as well. |
1705.06951 | Carlos Tamarit | C. Tamarit | Standard Model - Axion - Seesaw - H portal inflation | 8 pages, 2 figures, Contribution to the proceedings of the 52nd
Rencontres de Moriond conference, Electroweak session, La Thuile (Italy)
2017. v2: References added | null | null | IPPP/17/42 | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Extending the Standard Model with a new complex singlet scalar, right-handed
neutrinos and a vector-like quark allows to simultaneously tackle several
problems in particle physics and cosmology within a constrained framework that
can be falsified by future probes of the cosmic microwave background, as well
as by upcoming axion experiments. This Standard Model - Axion - Seesaw - H
portal inflation theory (SMASH) provides predictive inflation and $H$ boson
stabilization, and can explain baryogenesis, light neutrino masses, dark matter
and the strong CP problem. The model contains a unique new mass scale which
coincides with the axion decay constant, and also sets the scale for
perturbative lepton-number violation processes. Testable predictions include a
minimum value of the tensor-to-scalar ratio of $r\gtrsim 0.004$, a running of
the spectral index $\alpha\gtrsim-8\times10^{-4}$, a change $\delta N_{\rm
eff}\sim 0.03$ in the number of effective relativistic neutrinos, and an axion
mass in the range $50\mu eV\leq m_A \leq 200 \mu eV$.
| [
{
"created": "Fri, 19 May 2017 12:09:14 GMT",
"version": "v1"
},
{
"created": "Wed, 21 Jun 2017 10:24:04 GMT",
"version": "v2"
}
] | 2017-06-22 | [
[
"Tamarit",
"C.",
""
]
] | Extending the Standard Model with a new complex singlet scalar, right-handed neutrinos and a vector-like quark allows to simultaneously tackle several problems in particle physics and cosmology within a constrained framework that can be falsified by future probes of the cosmic microwave background, as well as by upcoming axion experiments. This Standard Model - Axion - Seesaw - H portal inflation theory (SMASH) provides predictive inflation and $H$ boson stabilization, and can explain baryogenesis, light neutrino masses, dark matter and the strong CP problem. The model contains a unique new mass scale which coincides with the axion decay constant, and also sets the scale for perturbative lepton-number violation processes. Testable predictions include a minimum value of the tensor-to-scalar ratio of $r\gtrsim 0.004$, a running of the spectral index $\alpha\gtrsim-8\times10^{-4}$, a change $\delta N_{\rm eff}\sim 0.03$ in the number of effective relativistic neutrinos, and an axion mass in the range $50\mu eV\leq m_A \leq 200 \mu eV$. |
1804.09766 | Cen Zhang | Eleni Vryonidou, Cen Zhang | Dimension-six electroweak top-loop effects in Higgs production and decay | 38 pages, 9 figures, version accepted by JHEP | null | 10.1007/JHEP08(2018)036 | CERN-TH-2018-097 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the next-to-leading order electroweak corrections to Higgs processes
from dimension-six top-quark operators in the Standard Model Effective Field
Theory approach. We consider the major production channels, including $WH$,
$ZH$, and VBF production at the LHC, and $ZH$, VBF production at future lepton
colliders, as well as the major decay channels including $H\to \gamma\gamma,
\gamma Z, Wl\nu,Zll,b\bar b,\mu\mu,\tau\tau$. The results show that within the
current constraints, top-quark operators can shift the signal strength of the
loop-induced processes, i.e. $H\to \gamma\gamma,\gamma Z$, by factors of
$\sim\mathcal{O}(1)-\mathcal{O}(10)$, and that of the tree-level processes,
i.e. all remaining production and decay channels, by $\sim5-10\%$ at the LHC,
and up to $\sim15\%$ at future lepton colliders. This implies that essentially
all Higgs channels have started to become sensitive to top-quark couplings, and
in particular, Higgs observables at high luminosity LHC as well as future
lepton colliders, even below the $t\bar t$ threshold, will improve our
knowledge of top-quark couplings. We derive the sensitivities of Higgs
measurements to top-quark operators at the high luminosity LHC, using
projections for both inclusive and differential measurements. We conclude that
treating the dimension-six top-quark sector and the Higgs/electroweak sector
separately may not continue to be a good strategy. A global analysis combining
Higgs and top-quark measurements is desirable, and our calculation and
implementation provide an automatic and realistic simulation tool for this
purpose.
| [
{
"created": "Wed, 25 Apr 2018 19:32:12 GMT",
"version": "v1"
},
{
"created": "Mon, 1 Oct 2018 08:51:19 GMT",
"version": "v2"
}
] | 2018-10-02 | [
[
"Vryonidou",
"Eleni",
""
],
[
"Zhang",
"Cen",
""
]
] | We study the next-to-leading order electroweak corrections to Higgs processes from dimension-six top-quark operators in the Standard Model Effective Field Theory approach. We consider the major production channels, including $WH$, $ZH$, and VBF production at the LHC, and $ZH$, VBF production at future lepton colliders, as well as the major decay channels including $H\to \gamma\gamma, \gamma Z, Wl\nu,Zll,b\bar b,\mu\mu,\tau\tau$. The results show that within the current constraints, top-quark operators can shift the signal strength of the loop-induced processes, i.e. $H\to \gamma\gamma,\gamma Z$, by factors of $\sim\mathcal{O}(1)-\mathcal{O}(10)$, and that of the tree-level processes, i.e. all remaining production and decay channels, by $\sim5-10\%$ at the LHC, and up to $\sim15\%$ at future lepton colliders. This implies that essentially all Higgs channels have started to become sensitive to top-quark couplings, and in particular, Higgs observables at high luminosity LHC as well as future lepton colliders, even below the $t\bar t$ threshold, will improve our knowledge of top-quark couplings. We derive the sensitivities of Higgs measurements to top-quark operators at the high luminosity LHC, using projections for both inclusive and differential measurements. We conclude that treating the dimension-six top-quark sector and the Higgs/electroweak sector separately may not continue to be a good strategy. A global analysis combining Higgs and top-quark measurements is desirable, and our calculation and implementation provide an automatic and realistic simulation tool for this purpose. |
2206.04540 | Kevin A. Urqu\'ia Calder\'on | Kevin A. Urqu\'ia-Calder\'on, Inar Timiryasov, Oleg Ruchayskiy | Heavy Neutral Leptons -- Advancing into the PeV domain | 29 pages, 11 figures. Updated to JHEP version | J. High Energ. Phys. 2023, 167 (2023) | 10.1007/JHEP08(2023)167 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Heavy neutral leptons (HNLs) are hypothetical particles able to explain
neutrino oscillations and provide a mechanism for generating the baryon
asymmetry of the Universe. Quantum corrections due to such particles give rise
to flavor violating processes in the charged lepton sector. Based on the fact
that these corrections grow with HNL masses, we improve existing constraints by
orders of magnitude in mass and mixing angle. This allows us to probe part of
the parameter space of leptogenesis with multi-TeV HNLs. We also show that one
will be able to infer HNL parameters in a significant portion of the parameter
space for TeV-PeV masses if charged lepton flavor violating signals are
detected.
| [
{
"created": "Thu, 9 Jun 2022 14:38:32 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Aug 2023 09:48:23 GMT",
"version": "v2"
}
] | 2023-08-29 | [
[
"Urquía-Calderón",
"Kevin A.",
""
],
[
"Timiryasov",
"Inar",
""
],
[
"Ruchayskiy",
"Oleg",
""
]
] | Heavy neutral leptons (HNLs) are hypothetical particles able to explain neutrino oscillations and provide a mechanism for generating the baryon asymmetry of the Universe. Quantum corrections due to such particles give rise to flavor violating processes in the charged lepton sector. Based on the fact that these corrections grow with HNL masses, we improve existing constraints by orders of magnitude in mass and mixing angle. This allows us to probe part of the parameter space of leptogenesis with multi-TeV HNLs. We also show that one will be able to infer HNL parameters in a significant portion of the parameter space for TeV-PeV masses if charged lepton flavor violating signals are detected. |
hep-ph/9803385 | Thomas G. Rizzo | Thomas G. Rizzo | Right-Handed Currents in B Decay Revisited | 52 pages, 8 figs, LaTex, typos corrected, references added, slight
augmentation of discussion | Phys.Rev.D58:055009,1998 | 10.1103/PhysRevD.58.055009 | SLAC-PUB-7738 | hep-ph | null | We critically re-examine the case for and against a sizeable right-handed
component in the $b\to c$ charged current coupling with a strength $\xi$
relative to the conventional left-handed current. Using data from CLEO on the
decay $B\to D^*\ell \nu$, as well as our knowledge of $V_{cb}$ extracted from
both inclusive and exclusive processes, we are able to determine the presently
allowed parameter space for $\xi$ via HQET. We then identify several
observables which could be measured at $B$ factories to either strengthen these
constraints or otherwise observe right-handed currents. This parameter space
region is found to be consistent with the low degree of $\Lambda_b$
polarization as determined by ALEPH as well as the measurements of the charged
lepton and neutrino energy spectra from $b$ decay made by L3. We discuss how
future measurements of semileptonic decay distributions may distinguish between
exotic $\Lambda_b$ depolarization mechanisms and the existence of right-handed
currents. Within the parameter space allowed by CLEO, using the Left-Right
Symmetric Model as a guide, we perform a detailed search for specific
sub-regions which can lead to a reduction in both the $B$ semileptonic
branching fraction as well as the the average yield of charmed quarks in $B$
decay. The results provide a concrete realization of an earlier suggestion by
Voloshin but may lead to potential difficulties with certain penguin mediated
decay processes.
| [
{
"created": "Wed, 18 Mar 1998 21:28:21 GMT",
"version": "v1"
},
{
"created": "Fri, 3 Apr 1998 19:10:47 GMT",
"version": "v2"
},
{
"created": "Thu, 30 Apr 1998 22:49:30 GMT",
"version": "v3"
}
] | 2014-11-17 | [
[
"Rizzo",
"Thomas G.",
""
]
] | We critically re-examine the case for and against a sizeable right-handed component in the $b\to c$ charged current coupling with a strength $\xi$ relative to the conventional left-handed current. Using data from CLEO on the decay $B\to D^*\ell \nu$, as well as our knowledge of $V_{cb}$ extracted from both inclusive and exclusive processes, we are able to determine the presently allowed parameter space for $\xi$ via HQET. We then identify several observables which could be measured at $B$ factories to either strengthen these constraints or otherwise observe right-handed currents. This parameter space region is found to be consistent with the low degree of $\Lambda_b$ polarization as determined by ALEPH as well as the measurements of the charged lepton and neutrino energy spectra from $b$ decay made by L3. We discuss how future measurements of semileptonic decay distributions may distinguish between exotic $\Lambda_b$ depolarization mechanisms and the existence of right-handed currents. Within the parameter space allowed by CLEO, using the Left-Right Symmetric Model as a guide, we perform a detailed search for specific sub-regions which can lead to a reduction in both the $B$ semileptonic branching fraction as well as the the average yield of charmed quarks in $B$ decay. The results provide a concrete realization of an earlier suggestion by Voloshin but may lead to potential difficulties with certain penguin mediated decay processes. |
hep-ph/9208206 | null | L. Xiong, E. Shuryak and G. E. Brown | Photon production through $A_1$ resonance in high energy heavy ion
collisions | null | Phys.Rev.D46:3798-3801,1992 | 10.1103/PhysRevD.46.3798 | null | hep-ph | null | Electromagnetic radiation from excited hadronic matter is one of the best
ways to study the properties of the matter.
Considering various processes in the hadronic gas, Kapusta et al
\cite{Kapusta_photons} have found a $\pi\rho \rightarrow \pi\gamma$ reaction
with intermediate virtual pion or rho to be the main source of photons with
energy greater than 0.7 GeV.
However, at temperatures considered T=100-200 MeV, a $\pi\rho$ pair can
easily form an $A_1$(1260) resonance, and we show that this mechanism leads to
the photon production rates exceeding those suggested previously. The paper is
in LATEX, figures available from authors.
| [
{
"created": "Tue, 4 Aug 1992 18:21:04 GMT",
"version": "v1"
}
] | 2010-11-01 | [
[
"Xiong",
"L.",
""
],
[
"Shuryak",
"E.",
""
],
[
"Brown",
"G. E.",
""
]
] | Electromagnetic radiation from excited hadronic matter is one of the best ways to study the properties of the matter. Considering various processes in the hadronic gas, Kapusta et al \cite{Kapusta_photons} have found a $\pi\rho \rightarrow \pi\gamma$ reaction with intermediate virtual pion or rho to be the main source of photons with energy greater than 0.7 GeV. However, at temperatures considered T=100-200 MeV, a $\pi\rho$ pair can easily form an $A_1$(1260) resonance, and we show that this mechanism leads to the photon production rates exceeding those suggested previously. The paper is in LATEX, figures available from authors. |
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