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2109.13426
Andrew Fowlie Assoc. Prof.
Andrew Fowlie
Comment on "Accumulating Evidence for the Associate Production of a Neutral Scalar with Mass around 151 GeV"
2 pages + refs, 1 figure. added further discussion of LEE. closely matches version accepted for publication in Phys.Lett.B
null
10.1016/j.physletb.2022.136936
null
hep-ph physics.data-an
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A recent paper [2109.02650] accumulates evidence for a new fundamental particle by combining several CMS and ATLAS searches for the Standard Model Higgs boson. The putative particle is a neutral scalar, $S$, with a mass of about 151 GeV. The reported significances are $5.1\sigma$ local and $4.8\sigma$ global. This nearly reaches the $5\sigma$ threshold for a discovery in high-energy physics. In this brief note we cast doubt on the strength of the evidence for a new particle. After taking into account the fact that signals were fitted to six different channels, we find that the significances are only $4.1\sigma$ local and $3.5\sigma$ global. The code and instructions for reproducing our calculations are available at https://github.com/andrewfowlie/accumulating_evidence.
[ { "created": "Tue, 28 Sep 2021 01:31:45 GMT", "version": "v1" }, { "created": "Fri, 28 Jan 2022 02:05:39 GMT", "version": "v2" } ]
2022-02-03
[ [ "Fowlie", "Andrew", "" ] ]
A recent paper [2109.02650] accumulates evidence for a new fundamental particle by combining several CMS and ATLAS searches for the Standard Model Higgs boson. The putative particle is a neutral scalar, $S$, with a mass of about 151 GeV. The reported significances are $5.1\sigma$ local and $4.8\sigma$ global. This nearly reaches the $5\sigma$ threshold for a discovery in high-energy physics. In this brief note we cast doubt on the strength of the evidence for a new particle. After taking into account the fact that signals were fitted to six different channels, we find that the significances are only $4.1\sigma$ local and $3.5\sigma$ global. The code and instructions for reproducing our calculations are available at https://github.com/andrewfowlie/accumulating_evidence.
hep-ph/0402275
A. D. Polosa
L. Maiani, F. Piccinini, A.D. Polosa, V. Riquer
J/psi Absorption in Heavy Ion Collisions
12 pages, 7 figures
Nucl.Phys. A741 (2004) 273-286
10.1016/j.nuclphysa.2004.05.019
null
hep-ph nucl-th
null
We present a new calculation of the pi-J/psi dissociation cross sections within the Constituent Quark-Meson Model recently introduced. To discuss the absorption of J/psi in heavy-ion collisions, we assume the J/psi to be produced inside a thermalized pion gas, as discussed by Bjorken, and introduce the corrections due to absorption by nuclear matter as well. We fit the absorption length of the J/psi to the data obtained at the CERN SPS by the NA50 Collaboration for Pb-Pb collisions. Collisions of lower centrality allow us to determine the temperature and the energy density of the pion gas. For both these quantities we find values close to those indicated by lattice gauge calculations for the transition to a quark-gluon plasma. A simple extrapolation to more central collisions, which takes into account the increase of the energy deposited due to the increased nucleon flux, fails to reproduce the break in J/psi absorption indicated by NA50, thus lending support to the idea that an unconfined quark-gluon phase may have been produced. This conclusion could be sharpened by analysing in a similar way, as a function of centrality, other observables such as strange particle production.
[ { "created": "Thu, 26 Feb 2004 12:09:55 GMT", "version": "v1" } ]
2009-11-10
[ [ "Maiani", "L.", "" ], [ "Piccinini", "F.", "" ], [ "Polosa", "A. D.", "" ], [ "Riquer", "V.", "" ] ]
We present a new calculation of the pi-J/psi dissociation cross sections within the Constituent Quark-Meson Model recently introduced. To discuss the absorption of J/psi in heavy-ion collisions, we assume the J/psi to be produced inside a thermalized pion gas, as discussed by Bjorken, and introduce the corrections due to absorption by nuclear matter as well. We fit the absorption length of the J/psi to the data obtained at the CERN SPS by the NA50 Collaboration for Pb-Pb collisions. Collisions of lower centrality allow us to determine the temperature and the energy density of the pion gas. For both these quantities we find values close to those indicated by lattice gauge calculations for the transition to a quark-gluon plasma. A simple extrapolation to more central collisions, which takes into account the increase of the energy deposited due to the increased nucleon flux, fails to reproduce the break in J/psi absorption indicated by NA50, thus lending support to the idea that an unconfined quark-gluon phase may have been produced. This conclusion could be sharpened by analysing in a similar way, as a function of centrality, other observables such as strange particle production.
hep-ph/9610521
Masanori Hirai
M. Hirai, S. Kumano, and M. Miyama
Numerical solution of NLO Q^2 evolution equations for spin-dependent structure functions
4 pages, Latex with epsf.sty, epsfig.sty, and wrapfig.sty 3 eps figures. Talk given at the 12th International Symposium on High-Energy Spin Physics. Amsterdam, The Netherlands, September 10-14, 1996. Complete postscript file including the figures is available at ftp://ftp.cc.saga-u.ac.jp/pub/paper/riko/quantum1 or at http://www.cc.saga-u.ac.jp/saga-u/riko/physics/quantum1/structure.html Email:96sm18, kumanos, 96td25@cc.saga-u.ac.jp
null
null
SAGA-HE-109-96
hep-ph nucl-th
null
Numerical solution of DGLAP $Q^2$ evolution equations is studied for polarized parton distributions by using a ``brute-force" method. NLO contributions to splitting functions are recently calculated,and they are included in our analysis. Numerical results in polarized parton distributions and in the structure function $g_1$ are shown. In particular, we discuss how numerical accuracy depends on number of steps in the variable $x$ and in $Q^2$.
[ { "created": "Tue, 29 Oct 1996 09:04:15 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hirai", "M.", "" ], [ "Kumano", "S.", "" ], [ "Miyama", "M.", "" ] ]
Numerical solution of DGLAP $Q^2$ evolution equations is studied for polarized parton distributions by using a ``brute-force" method. NLO contributions to splitting functions are recently calculated,and they are included in our analysis. Numerical results in polarized parton distributions and in the structure function $g_1$ are shown. In particular, we discuss how numerical accuracy depends on number of steps in the variable $x$ and in $Q^2$.
hep-ph/9604390
null
J.Matias (University of Padova)
The effective chiral lagrangian of the MSM at one and two loop order
34 pages, LaTeX, 10 figures (also available upon request)
Nucl.Phys. B478 (1996) 90-122
10.1016/0550-3213(96)00388-4
DFPD 96/TH/18
hep-ph
null
The formalism of the matching conditions between transverse connected Green functions is extended to include the two next to leading corrections, namely the two-loop $M_{H}^{2}$ and the one-loop $1/M_{H}^{2}$ contributions to the coefficients of the electroweak chiral lagrangian which are relevant to the LEP1 physics: $a_{0}$, ${\hat a}_{1}$ and ${\hat a}_{8}$. We derive general expressions for these three coefficients in terms of just bare gauge boson self-energies. By means of the screening theorem, it is shown that the same expressions can be used to get directly from a MSM calculation, the leading Higgs mass contribution to these coefficients at each loop order. In a more general framework, we solve the problems concerning the loss of gauge invariance and the inclusion of only gauge invariant operators by proposing a new formulation of the matching conditions at two and higher loop order. As an example of the usefulness of using an electroweak chiral lagrangian to parametrize the MSM, we will give a simple proof of an extra screening for the renormalized photon self-energy in the on-shell scheme at all orders. In addition it is shown the automatic cancellation of the unphysical $M_{H}^4$ terms in the other gauge boson self-energies at two-loops in this scheme. Finally we will apply the obtained electroweak chiral lagrangian to compute the different Higgs mass contributions to the bosonic part of $\Delta \rho$, $\Delta r$ and $\Delta \kappa$, analyzing carefully the hierarchy between corrections.
[ { "created": "Tue, 23 Apr 1996 19:14:44 GMT", "version": "v1" } ]
2009-10-28
[ [ "Matias", "J.", "", "University of Padova" ] ]
The formalism of the matching conditions between transverse connected Green functions is extended to include the two next to leading corrections, namely the two-loop $M_{H}^{2}$ and the one-loop $1/M_{H}^{2}$ contributions to the coefficients of the electroweak chiral lagrangian which are relevant to the LEP1 physics: $a_{0}$, ${\hat a}_{1}$ and ${\hat a}_{8}$. We derive general expressions for these three coefficients in terms of just bare gauge boson self-energies. By means of the screening theorem, it is shown that the same expressions can be used to get directly from a MSM calculation, the leading Higgs mass contribution to these coefficients at each loop order. In a more general framework, we solve the problems concerning the loss of gauge invariance and the inclusion of only gauge invariant operators by proposing a new formulation of the matching conditions at two and higher loop order. As an example of the usefulness of using an electroweak chiral lagrangian to parametrize the MSM, we will give a simple proof of an extra screening for the renormalized photon self-energy in the on-shell scheme at all orders. In addition it is shown the automatic cancellation of the unphysical $M_{H}^4$ terms in the other gauge boson self-energies at two-loops in this scheme. Finally we will apply the obtained electroweak chiral lagrangian to compute the different Higgs mass contributions to the bosonic part of $\Delta \rho$, $\Delta r$ and $\Delta \kappa$, analyzing carefully the hierarchy between corrections.
1602.07540
Hungchong Kim
Hungchong Kim, K. S. Kim, Myung-Ki Cheoun, Daisuke Jido, Makoto Oka
Testing the tetraquark structure for the $X$ resonances in low-lying region
8 pages, substantially revised, more references are added, the version to be published in EPJA
null
10.1140/epja/i2016-16184-0
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Assuming four-quark structure for the $X$ resonances in low-lying region, we calculate their masses using the color-spin interaction. In specific, the hyperfine masses of the color-spin interaction are calculated for the possible states in spin-0, spin-1, spin-2 channels. The two states in spin-0 channel as well as the two states in spin-1 channel are diagonalized in order to generate the physical hyperfine masses. By matching the difference in hyperfine masses with the splitting in corresponding hadron masses and using the $X(3872)$ mass as an input, we estimate the masses corresponding to the states $J^{PC}=0^{++}, 1^{+-},2^{++}$. We find the masses of two states in $1^{+-}$ are close to those of $X(3823)$, $X(3900)$, and the mass of the $2^{++}$ state is close to that of $X(3940)$. For them, the discrepancies are about $\sim 10$ MeV. This may suggest that the quantum numbers of the controversial states are $X(3823)=1^{+-}, X(3900)=1^{+-}, X(3940)=2^{++}$. In this work, we use the same inputs parameters, the constituent quark masses and the strength of the color-spin interaction, that have been adopted in the previous work on the $D$ or $B$-meson excited states. There, it was shown that the four-quark structure can be manifested in their excited states. Thus, our results in this work provide a consistent treatment on open- and hidden-charm mesons as far as the four-quark model is concerned.
[ { "created": "Wed, 24 Feb 2016 14:58:14 GMT", "version": "v1" }, { "created": "Thu, 25 Feb 2016 09:09:57 GMT", "version": "v2" }, { "created": "Mon, 6 Jun 2016 10:04:17 GMT", "version": "v3" } ]
2016-07-20
[ [ "Kim", "Hungchong", "" ], [ "Kim", "K. S.", "" ], [ "Cheoun", "Myung-Ki", "" ], [ "Jido", "Daisuke", "" ], [ "Oka", "Makoto", "" ] ]
Assuming four-quark structure for the $X$ resonances in low-lying region, we calculate their masses using the color-spin interaction. In specific, the hyperfine masses of the color-spin interaction are calculated for the possible states in spin-0, spin-1, spin-2 channels. The two states in spin-0 channel as well as the two states in spin-1 channel are diagonalized in order to generate the physical hyperfine masses. By matching the difference in hyperfine masses with the splitting in corresponding hadron masses and using the $X(3872)$ mass as an input, we estimate the masses corresponding to the states $J^{PC}=0^{++}, 1^{+-},2^{++}$. We find the masses of two states in $1^{+-}$ are close to those of $X(3823)$, $X(3900)$, and the mass of the $2^{++}$ state is close to that of $X(3940)$. For them, the discrepancies are about $\sim 10$ MeV. This may suggest that the quantum numbers of the controversial states are $X(3823)=1^{+-}, X(3900)=1^{+-}, X(3940)=2^{++}$. In this work, we use the same inputs parameters, the constituent quark masses and the strength of the color-spin interaction, that have been adopted in the previous work on the $D$ or $B$-meson excited states. There, it was shown that the four-quark structure can be manifested in their excited states. Thus, our results in this work provide a consistent treatment on open- and hidden-charm mesons as far as the four-quark model is concerned.
1208.2537
Yannis Burnier
Y. Burnier, D. E. Kharzeev, J. Liao, H.-U. Yee
From the chiral magnetic wave to the charge dependence of elliptic flow
Contains 12 pages, 6 figures, written as a proceeding for the talk of Y. Burnier at the conference "P and CP-odd Effects in Hot and Dense Matter 2012" held in BNL
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The quark-gluon plasma formed in heavy ion collisions contains charged chiral fermions evolving in an external magnetic field. At finite density of electric charge or baryon number (resulting either from nuclear stopping or from fluctuations), the triangle anomaly induces in the plasma the Chiral Magnetic Wave (CMW). The CMW first induces a separation of the right and left chiral charges along the magnetic field; the resulting dipolar axial charge density in turn induces the oppositely directed vector charge currents leading to an electric quadrupole moment of the quark-gluon plasma. Boosted by the strong collective flow, the electric quadrupole moment translates into the charge dependence of the elliptic flow coefficients, so that $v_2(\pi^+) < v_2(\pi^-)$ (at positive net charge). Using the latest quantitative simulations of the produced magnetic field and solving the CMW equation, we make further quantitative estimates of the produced $v_2$ splitting and its centrality dependence. We compare the results with the available experimental data.
[ { "created": "Mon, 13 Aug 2012 09:53:44 GMT", "version": "v1" } ]
2012-08-14
[ [ "Burnier", "Y.", "" ], [ "Kharzeev", "D. E.", "" ], [ "Liao", "J.", "" ], [ "Yee", "H. -U.", "" ] ]
The quark-gluon plasma formed in heavy ion collisions contains charged chiral fermions evolving in an external magnetic field. At finite density of electric charge or baryon number (resulting either from nuclear stopping or from fluctuations), the triangle anomaly induces in the plasma the Chiral Magnetic Wave (CMW). The CMW first induces a separation of the right and left chiral charges along the magnetic field; the resulting dipolar axial charge density in turn induces the oppositely directed vector charge currents leading to an electric quadrupole moment of the quark-gluon plasma. Boosted by the strong collective flow, the electric quadrupole moment translates into the charge dependence of the elliptic flow coefficients, so that $v_2(\pi^+) < v_2(\pi^-)$ (at positive net charge). Using the latest quantitative simulations of the produced magnetic field and solving the CMW equation, we make further quantitative estimates of the produced $v_2$ splitting and its centrality dependence. We compare the results with the available experimental data.
hep-ph/0308008
Gino Isidori
Gerhard Buchalla, Giancarlo D'Ambrosio, Gino Isidori
Extracting short-distance physics from K_{L,S} -> pi0 e+ e- decays
24 pages, 6 figures; v2: minor modifications, published version
Nucl.Phys.B672:387-408,2003
10.1016/j.nuclphysb.2003.09.010
null
hep-ph
null
We present a new analysis of the rare decay K_L -> pi0 e+ e- taking into account important experimental progress that has recently been achieved in measuring K_L -> pi0 gamma gamma and K_S -> pi0 e+ e-. This includes a brief review of the direct CP-violating component, a calculation of the indirect CP-violating contribution, which is now possible after the measurement of K_S -> pi0 e+ e-, and a re-analysis of the CP conserving part. The latter is shown to be negligible, based on experimental input from K_L -> pi0 gamma gamma, a more general treatment of the form factor entering the dispersive contribution, and on a comparison with the CP violating rate, which can now be estimated reliably. We predict B(K_L -> pi0 e+ e-) = (3.2 +1.2 -0.8) 10^{-11} in the Standard Model, dominated by CP violation with a sizable contribution (~40%) from the direct effect, largely through interference with the indirect one. Methods to deal with the severe backgrounds for K_L -> pi0 e+ e- using Dalitz-plot analysis and time-dependent K_L-K_S interference are also briefly discussed.
[ { "created": "Fri, 1 Aug 2003 09:40:39 GMT", "version": "v1" }, { "created": "Tue, 4 Nov 2003 12:30:35 GMT", "version": "v2" } ]
2009-10-09
[ [ "Buchalla", "Gerhard", "" ], [ "D'Ambrosio", "Giancarlo", "" ], [ "Isidori", "Gino", "" ] ]
We present a new analysis of the rare decay K_L -> pi0 e+ e- taking into account important experimental progress that has recently been achieved in measuring K_L -> pi0 gamma gamma and K_S -> pi0 e+ e-. This includes a brief review of the direct CP-violating component, a calculation of the indirect CP-violating contribution, which is now possible after the measurement of K_S -> pi0 e+ e-, and a re-analysis of the CP conserving part. The latter is shown to be negligible, based on experimental input from K_L -> pi0 gamma gamma, a more general treatment of the form factor entering the dispersive contribution, and on a comparison with the CP violating rate, which can now be estimated reliably. We predict B(K_L -> pi0 e+ e-) = (3.2 +1.2 -0.8) 10^{-11} in the Standard Model, dominated by CP violation with a sizable contribution (~40%) from the direct effect, largely through interference with the indirect one. Methods to deal with the severe backgrounds for K_L -> pi0 e+ e- using Dalitz-plot analysis and time-dependent K_L-K_S interference are also briefly discussed.
1105.0656
Bipin singh Koranga
K.Chaturvedi, Bipin Singh Koranga and Vinod Kumar
Analytic Calculation of Neutrino Mass Eigenvalues
10 pages
null
10.1007/s10773-011-0942-4
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Implicaion of the neutrino oscillation search for the neutrino mass square difference and mixing are discussed. We have considered the effective majorana mass m_{ee}, related for \beta\beta_{0\nu}decay. We find limits for neutrino mass eigen value m_{i} in the different neutrino mass spectrum,which explain the different neutrino data.
[ { "created": "Tue, 3 May 2011 19:13:18 GMT", "version": "v1" } ]
2015-05-28
[ [ "Chaturvedi", "K.", "" ], [ "Koranga", "Bipin Singh", "" ], [ "Kumar", "Vinod", "" ] ]
Implicaion of the neutrino oscillation search for the neutrino mass square difference and mixing are discussed. We have considered the effective majorana mass m_{ee}, related for \beta\beta_{0\nu}decay. We find limits for neutrino mass eigen value m_{i} in the different neutrino mass spectrum,which explain the different neutrino data.
hep-ph/0101348
Martin A. Kimber
M.A. Kimber, A.D. Martin and M.G. Ryskin
Unintegrated parton distributions
LaTeX, 19 pages including 5 figures, submitted to Phys. Rev. D
Phys.Rev.D63:114027,2001
10.1103/PhysRevD.63.114027
IPPP/01/05 DCPT/01/10
hep-ph
null
We describe how to calculate the parton distributions $f_a(x, k_t^2, \mu^2)$, unintegrated over the parton transverse momentum $k_t$, from auxiliary functions $h_a(x, k_t^2)$, which satisfy single-scale evolution equations. The formalism embodies both DGLAP and BFKL contributions, and accounts for the angular ordering which comes from coherence effects in gluon emission. We check that the unintegrated distributions give the measured values of the deep inelastic structure function $F_2(x, Q^2)$.
[ { "created": "Wed, 31 Jan 2001 13:29:02 GMT", "version": "v1" } ]
2014-11-17
[ [ "Kimber", "M. A.", "" ], [ "Martin", "A. D.", "" ], [ "Ryskin", "M. G.", "" ] ]
We describe how to calculate the parton distributions $f_a(x, k_t^2, \mu^2)$, unintegrated over the parton transverse momentum $k_t$, from auxiliary functions $h_a(x, k_t^2)$, which satisfy single-scale evolution equations. The formalism embodies both DGLAP and BFKL contributions, and accounts for the angular ordering which comes from coherence effects in gluon emission. We check that the unintegrated distributions give the measured values of the deep inelastic structure function $F_2(x, Q^2)$.
hep-ph/9912548
Juerg Gasser
J. Gasser
Chiral perturbation theory
10 pages (LaTex), 1 figure embedded with epsfig.sty. Uses espcrc2.sty. Invited talk given at the QCD Euroconference 99, Montpellier, 7-13th July, 1999. The present article contains additional references as compared to the version that will appear in the proceedings
Nucl.Phys.Proc.Suppl.86:257-266,2000
10.1016/S0920-5632(00)00573-9
BUTP-99/32
hep-ph
null
I present an outline of chiral perturbation theory and discuss some recent developments in the field.
[ { "created": "Thu, 30 Dec 1999 18:17:16 GMT", "version": "v1" } ]
2008-11-26
[ [ "Gasser", "J.", "" ] ]
I present an outline of chiral perturbation theory and discuss some recent developments in the field.
1412.2703
Jianwei Qiu
Jian-Wei Qiu
Electron-Ion Collider - taking us to the next QCD frontier
8 pages, 4 figures, accepted contribution to the proceedings of "The QCD Evolution 2014 workshop", May 12-16, 2014, Santa Fe, NM
null
10.1142/S2010194515600204
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk, I demonstrate that the proposed Electron-Ion Collider (EIC) will be an ideal and unique future facility to address many overarching questions about QCD and strong interaction physics at one place. The EIC will be the world's first polarized electron-proton (and light ion), as well as the first electron-nucleus collider at flexible collision energies. With its high luminosity and beam polarization, the EIC distinguishes itself from HERA and the other fixed target electron-hadron facilities around the world. The EIC is capable of taking us to the next QCD frontier to explore the glue that binds us all.
[ { "created": "Mon, 8 Dec 2014 19:05:12 GMT", "version": "v1" } ]
2015-06-23
[ [ "Qiu", "Jian-Wei", "" ] ]
In this talk, I demonstrate that the proposed Electron-Ion Collider (EIC) will be an ideal and unique future facility to address many overarching questions about QCD and strong interaction physics at one place. The EIC will be the world's first polarized electron-proton (and light ion), as well as the first electron-nucleus collider at flexible collision energies. With its high luminosity and beam polarization, the EIC distinguishes itself from HERA and the other fixed target electron-hadron facilities around the world. The EIC is capable of taking us to the next QCD frontier to explore the glue that binds us all.
2301.06208
Wei-Liang Qian
Wei-Liang Qian, Hong-Hao Ma, Shao-Yu Yin and Ping Wang
On thermodynamically consistent quasiparticle model at finite chemical potential
12 pages, 5 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We explore the quasiparticle model at finite chemical potential related to Ru-Keng Su's distinguished contributions to the topic. Besides, we discuss recent developments in the model, and in particular, one argues that the effective mass of the quasiparticle might attain a specific form as a function of momentum, in addition to its dependence on temperature and chemical potential. Unlike the approaches based on the properties of underlying symmetry or renormalization group, the momentum dependence emerges as a special solution to an integro-differential equation resulting from the underlying thermodynamic consistency. Moreover, this special solution to the problem is shown to be more general than previously explored in the literature. Instead of fitting to the lattice QCD data at vanishing chemical potential, in this work, we adopt a ``bottom-up'' approach by assuming some analytic ansatzes that are manifestly thermodynamically consistent. The remaining physical quantities are subsequently derived, and possible implications are also addressed.
[ { "created": "Sun, 15 Jan 2023 23:14:43 GMT", "version": "v1" } ]
2023-01-18
[ [ "Qian", "Wei-Liang", "" ], [ "Ma", "Hong-Hao", "" ], [ "Yin", "Shao-Yu", "" ], [ "Wang", "Ping", "" ] ]
We explore the quasiparticle model at finite chemical potential related to Ru-Keng Su's distinguished contributions to the topic. Besides, we discuss recent developments in the model, and in particular, one argues that the effective mass of the quasiparticle might attain a specific form as a function of momentum, in addition to its dependence on temperature and chemical potential. Unlike the approaches based on the properties of underlying symmetry or renormalization group, the momentum dependence emerges as a special solution to an integro-differential equation resulting from the underlying thermodynamic consistency. Moreover, this special solution to the problem is shown to be more general than previously explored in the literature. Instead of fitting to the lattice QCD data at vanishing chemical potential, in this work, we adopt a ``bottom-up'' approach by assuming some analytic ansatzes that are manifestly thermodynamically consistent. The remaining physical quantities are subsequently derived, and possible implications are also addressed.
hep-ph/0110364
Tilman Plehn
T.Plehn (UW Madison), S.Su (Caltech), D.Zeppenfeld (UW Madison)
VLHC Predictions for H to tau tau in Weak Boson Fusion
Contribution to Snowmass 2001
eConf C010630 (2001) E405
null
MADPH-01-1246, CALT-68-2356
hep-ph
null
Higgs production in weak boson fusion with subsequent decay H to tau tau to e mu p_T_miss provides a means to measure Higgs Yukawa couplings and Higgs interactions to weak bosons. The potential precision of cross section measurements at a VLHC is investigated.
[ { "created": "Sun, 28 Oct 2001 21:25:09 GMT", "version": "v1" } ]
2007-05-23
[ [ "Plehn", "T.", "", "UW Madison" ], [ "Su", "S.", "", "Caltech" ], [ "Zeppenfeld", "D.", "", "UW Madison" ] ]
Higgs production in weak boson fusion with subsequent decay H to tau tau to e mu p_T_miss provides a means to measure Higgs Yukawa couplings and Higgs interactions to weak bosons. The potential precision of cross section measurements at a VLHC is investigated.
hep-ph/9707406
Anatoly A. Bolokhov
A.A. Bolokhov (1), M.V. Polyakov (2) and S.G. Sherman (2) ((1) St. Petersburg State University, (2) St. Petersburg Nuclear Physics Institute)
Phenomenological $ \pi N \to \pi \pi N $ Amplitude and Analysis of Low Energy Data on Total Cross Sections and 1--D Distributions
58 pages, Latex, 10 Postscript figures, uses epsf.sty
Eur.Phys.J. A1 (1998) 317-336
10.1007/s100500050066
SPbU-IP-97-13
hep-ph
null
We develop the phenomenological amplitude of the $\pi N \to \pi \pi N$ reaction describing the exchanges of $\Delta$ and $N_{*}$ along with the OPE mechanism. The contribution of the latter contains 4 independent low energy parameters (up to $O(k^{4})$ order). The terms of the polynomial background are added to stand for far resonances and for contact terms originating from the off-mass-shell interactions. These terms are introduced with the account of isotopic, crossing, $ C $, $ P $ and $ T $ symmetries of strong interactions. The data consisting of total cross sections in the energy region $ 0.300 \le P_{Lab} \le 500 $~MeV/c and 1D distributions from the bubble-chamber experiments for three reaction channels were undergoing fittings to determine free parameters of the amplitude. The best solutions are characterized by $ \chi^{2}_{DF} = $ 1.16. At the considered energies the isobar exchanges are found to be more important than OPE. The obtained solutions reveal the need in more precise data and/or in polarization measurements because of large correlations of isobar parameters with the OPE ones. The theoretical solutions were used for modeling the Chew-Low extrapolation and the Olsson-Turner threshold approach. It is shown that the noncritical application of the former results in 100% theoretical errors, the extracted values being in fact the random numbers. The results of the Olsson-Turner method are characterised by significant systematic errors coming from unknown details of isobar physics.
[ { "created": "Mon, 21 Jul 1997 16:03:50 GMT", "version": "v1" } ]
2015-06-25
[ [ "Bolokhov", "A. A.", "" ], [ "Polyakov", "M. V.", "" ], [ "Sherman", "S. G.", "" ] ]
We develop the phenomenological amplitude of the $\pi N \to \pi \pi N$ reaction describing the exchanges of $\Delta$ and $N_{*}$ along with the OPE mechanism. The contribution of the latter contains 4 independent low energy parameters (up to $O(k^{4})$ order). The terms of the polynomial background are added to stand for far resonances and for contact terms originating from the off-mass-shell interactions. These terms are introduced with the account of isotopic, crossing, $ C $, $ P $ and $ T $ symmetries of strong interactions. The data consisting of total cross sections in the energy region $ 0.300 \le P_{Lab} \le 500 $~MeV/c and 1D distributions from the bubble-chamber experiments for three reaction channels were undergoing fittings to determine free parameters of the amplitude. The best solutions are characterized by $ \chi^{2}_{DF} = $ 1.16. At the considered energies the isobar exchanges are found to be more important than OPE. The obtained solutions reveal the need in more precise data and/or in polarization measurements because of large correlations of isobar parameters with the OPE ones. The theoretical solutions were used for modeling the Chew-Low extrapolation and the Olsson-Turner threshold approach. It is shown that the noncritical application of the former results in 100% theoretical errors, the extracted values being in fact the random numbers. The results of the Olsson-Turner method are characterised by significant systematic errors coming from unknown details of isobar physics.
hep-ph/9610325
null
S. Ishida, M. Y. Ishida, H. Takahashi, T. Ishida, K. Takamatsu and T. Tsuru
An Analysis of \pi\pi-Scattering Phase Shift and Existence of \sigma(555) particle
22 pages, Latex with Prog. Theor. Phys. format PTPTEX.sty, 4 EPS figures
Prog.Theor.Phys.95:745-766,1996
10.1143/PTP.95.745
NUP-A-95-13, KEK Preprint 95-183 (November 22, 1995)
hep-ph
null
In most of the Nambu:Jona-Lasinio(NJL)-type models, realizing the hidden chiral symmetry, the existence of a scalar particle \sigma is needed with a mass m_\sigma=2 m_q, as a partner of the Nambu-Goldstone boson \pi. However, the results of many analyses on \pi\pi phase-shift thus far made have been negative for its existence. In this paper we re-analyze the phase-shift, applying a new method, the interfering amplitude method, which treats the T-matrix directly and describes multi-resonances in conformity with the unitarity. As a result, the existence of \sigma has been strongly suggested from the behavior of the \pi\pi-->\pi\pi phase shift between the \pi\pi- and the KK- thresholds, with mass = 553.3 +- 0.5_{st} MeV and width= 242.6 +- 1.2_{st} MeV. The most crucial point in our analysis is the introduction of a negative background phase, possibly reflecting a ``repulsive core" in \pi\pi interactions. The properties of f_0(980) are also investigated from data including those over the KK threshold. Its mass is obtained as 993.2 +- 6.5_{st} +- 6.9_{sys} MeV. Its width is about a hundred MeV, although this depends largely on the treatment of the elasticity and the \pi\pi-->KK phase shift, both of which may have large experimental uncertainties.
[ { "created": "Thu, 10 Oct 1996 23:56:38 GMT", "version": "v1" } ]
2008-11-26
[ [ "Ishida", "S.", "" ], [ "Ishida", "M. Y.", "" ], [ "Takahashi", "H.", "" ], [ "Ishida", "T.", "" ], [ "Takamatsu", "K.", "" ], [ "Tsuru", "T.", "" ] ]
In most of the Nambu:Jona-Lasinio(NJL)-type models, realizing the hidden chiral symmetry, the existence of a scalar particle \sigma is needed with a mass m_\sigma=2 m_q, as a partner of the Nambu-Goldstone boson \pi. However, the results of many analyses on \pi\pi phase-shift thus far made have been negative for its existence. In this paper we re-analyze the phase-shift, applying a new method, the interfering amplitude method, which treats the T-matrix directly and describes multi-resonances in conformity with the unitarity. As a result, the existence of \sigma has been strongly suggested from the behavior of the \pi\pi-->\pi\pi phase shift between the \pi\pi- and the KK- thresholds, with mass = 553.3 +- 0.5_{st} MeV and width= 242.6 +- 1.2_{st} MeV. The most crucial point in our analysis is the introduction of a negative background phase, possibly reflecting a ``repulsive core" in \pi\pi interactions. The properties of f_0(980) are also investigated from data including those over the KK threshold. Its mass is obtained as 993.2 +- 6.5_{st} +- 6.9_{sys} MeV. Its width is about a hundred MeV, although this depends largely on the treatment of the elasticity and the \pi\pi-->KK phase shift, both of which may have large experimental uncertainties.
hep-ph/0606180
Yann Mambrini
Y. Mambrini
Signals from Galactic Center and Supergravity Models
6 pages, 3 figures, contributed to 41st Rencontres de Moriond on Electroweak Interactions and Unified Theories, La Thuile, Aosta Valley, Italy, 11-18 Mar 2006
null
null
null
hep-ph
null
We analyse the effect of the compression of the dark matter due to the infall of baryons to the galactic center on the gamma-ray flux. In addition, we also consider the effect of non-universal supersymmetric soft terms. This analysis shows that neutralino dark matter annihilation can give rise to signals largely reachable by future experiments like GLAST. This is a remarkable result if we realise that direct detection experiments will only be able to cover a small region of the parameter space. We have also studied the recent HESS data implying a neutralino heavier than 12 TeV. Because of such a heavy neutralino, it is not natural to find solutions in the SUGRA framework. Nevertheless we have carried out a quite model-independent analysis, and found the conditions required on the particle physics side to fit the HESS data thanks to dark matter annihilation.
[ { "created": "Fri, 16 Jun 2006 12:20:29 GMT", "version": "v1" } ]
2007-05-23
[ [ "Mambrini", "Y.", "" ] ]
We analyse the effect of the compression of the dark matter due to the infall of baryons to the galactic center on the gamma-ray flux. In addition, we also consider the effect of non-universal supersymmetric soft terms. This analysis shows that neutralino dark matter annihilation can give rise to signals largely reachable by future experiments like GLAST. This is a remarkable result if we realise that direct detection experiments will only be able to cover a small region of the parameter space. We have also studied the recent HESS data implying a neutralino heavier than 12 TeV. Because of such a heavy neutralino, it is not natural to find solutions in the SUGRA framework. Nevertheless we have carried out a quite model-independent analysis, and found the conditions required on the particle physics side to fit the HESS data thanks to dark matter annihilation.
hep-ph/0503132
Ruth Britto
Ruth Britto, Evgeny Buchbinder, Freddy Cachazo, Bo Feng
One-Loop Amplitudes Of Gluons In SQCD
49 pages, 4 figures, harvmac. v2: references added, typos fixed. v3: corrections to 3-mass-triangle coefficients, footnote 6 added, acknowledgments added. v4: a typo in formulas for the 3-mass-triangle coefficient is corrected, acknowledgments added
Phys.Rev.D72:065012,2005
10.1103/PhysRevD.72.065012
null
hep-ph hep-th
null
One-loop amplitudes of gluons in supersymmetric Yang-Mills are four-dimensional cut-constructible. This means that they can be determined from their unitarity cuts. We present a new systematic procedure to explicitly carry out any finite unitarity cut integral. The procedure naturally separates the contributions from bubble, triangle and box scalar integrals. This technique allows the systematic calculation of N=1 amplitudes of gluons. As an application we compute all next-to-MHV six-gluon amplitudes in N=1 super-Yang-Mills.
[ { "created": "Mon, 14 Mar 2005 19:32:55 GMT", "version": "v1" }, { "created": "Fri, 26 Aug 2005 13:38:16 GMT", "version": "v2" }, { "created": "Tue, 21 Feb 2006 16:43:32 GMT", "version": "v3" }, { "created": "Sat, 18 Mar 2006 20:43:30 GMT", "version": "v4" } ]
2009-07-09
[ [ "Britto", "Ruth", "" ], [ "Buchbinder", "Evgeny", "" ], [ "Cachazo", "Freddy", "" ], [ "Feng", "Bo", "" ] ]
One-loop amplitudes of gluons in supersymmetric Yang-Mills are four-dimensional cut-constructible. This means that they can be determined from their unitarity cuts. We present a new systematic procedure to explicitly carry out any finite unitarity cut integral. The procedure naturally separates the contributions from bubble, triangle and box scalar integrals. This technique allows the systematic calculation of N=1 amplitudes of gluons. As an application we compute all next-to-MHV six-gluon amplitudes in N=1 super-Yang-Mills.
hep-ph/9711351
Jean Letessier
Jean Letessier, Johann Rafelski, Ahmed Tounsi
Hot hadronic matter and strange anti-baryons
10 pages, LaTeX, 1 postscript figures
Phys.Lett.B292:417-423,1992
10.1016/0370-2693(92)91197-H
null
hep-ph nucl-th
null
We demonstrate that both quark-gluon plasma (QGP) and hadronic gas (HG) models of the central fireball created in S -> W collisions at 200 GeV A are possible sources of the recently observed strange (anti-) baryons. From the theoretical point of view, the HG interpretation we attempt remains more obscure because of the high fireball temperature required. The thermal properties of the fireball as determined by the particle ratios, are natural for the QGP state. We show that the total particle multiplicity emerging from the central rapidity region allows to distinguish between the two scenarios.
[ { "created": "Tue, 18 Nov 1997 00:25:43 GMT", "version": "v1" } ]
2010-11-01
[ [ "Letessier", "Jean", "" ], [ "Rafelski", "Johann", "" ], [ "Tounsi", "Ahmed", "" ] ]
We demonstrate that both quark-gluon plasma (QGP) and hadronic gas (HG) models of the central fireball created in S -> W collisions at 200 GeV A are possible sources of the recently observed strange (anti-) baryons. From the theoretical point of view, the HG interpretation we attempt remains more obscure because of the high fireball temperature required. The thermal properties of the fireball as determined by the particle ratios, are natural for the QGP state. We show that the total particle multiplicity emerging from the central rapidity region allows to distinguish between the two scenarios.
1909.00490
Miguel Fiolhais
Andrea Ferroglia, Miguel C. N. Fiolhais, Emanuel Gouveia, Ant\'onio Onofre
The Role of the $t{\bar t}h$ Rest Frame in Direct Top-Quark Yukawa Coupling Measurements
15 pages, 14 figures
Phys. Rev. D 100, 075034 (2019)
10.1103/PhysRevD.100.075034
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper studies new possibilities to directly measure a hypothetical $CP$-odd (pseudoscalar) component in the top-quark Yukawa coupling. In particular, the role of the $t{\bar t} h$ center-of-mass rest frame in the associated production of a top pair and a $h$ boson at the LHC is explored. The $h$ boson is assumed to have both a $CP$-even (scalar) and a $CP$-odd coupling to the top quark. The relative strength of the scalar and pseudoscalar components is regulated by an angle $\alpha$. Observables sensitive to the nature of the top-quark Yukawa coupling are proposed. These observables are defined in terms of the transverse and longitudinal projections of $t$, $\bar{t}$ and $h$ momenta with respect to the beam axis in the $t{\bar t} h$ rest frame. Distributions differential with respect to those observables are evaluated up to NLO in QCD. These distributions are found to be sensitive to the $CP$ nature of the coupling. Dileptonic final states of the $t{\bar t} h$ system (with $h\rightarrow b\bar b$) are used, after fast DELPHES detector simulation and full event reconstruction through a kinematic fit, as a case study to test the observables' sensitivity to the $CP$ nature of the coupling. Confidence levels are presented as a function of the total integrated LHC luminosity for the case of exclusion of a pure $CP$-odd coupling against the Standard Model $CP$-even hypothesis. By using observables evaluated in the $t{\bar t} h$ system, the luminosity needed to directly probe the $CP$ properties of the top-quark Yukawa coupling at the High-Luminosity run of the LHC can be decreased by a few hundred inverse femtobarns, when compared to analyses that use observables in the laboratory rest frame. In addition, transverse momentum distributions of the $h$ boson and top quarks are found to provide no more discriminant power than a counting experiment.
[ { "created": "Sun, 1 Sep 2019 23:28:03 GMT", "version": "v1" } ]
2019-10-29
[ [ "Ferroglia", "Andrea", "" ], [ "Fiolhais", "Miguel C. N.", "" ], [ "Gouveia", "Emanuel", "" ], [ "Onofre", "António", "" ] ]
This paper studies new possibilities to directly measure a hypothetical $CP$-odd (pseudoscalar) component in the top-quark Yukawa coupling. In particular, the role of the $t{\bar t} h$ center-of-mass rest frame in the associated production of a top pair and a $h$ boson at the LHC is explored. The $h$ boson is assumed to have both a $CP$-even (scalar) and a $CP$-odd coupling to the top quark. The relative strength of the scalar and pseudoscalar components is regulated by an angle $\alpha$. Observables sensitive to the nature of the top-quark Yukawa coupling are proposed. These observables are defined in terms of the transverse and longitudinal projections of $t$, $\bar{t}$ and $h$ momenta with respect to the beam axis in the $t{\bar t} h$ rest frame. Distributions differential with respect to those observables are evaluated up to NLO in QCD. These distributions are found to be sensitive to the $CP$ nature of the coupling. Dileptonic final states of the $t{\bar t} h$ system (with $h\rightarrow b\bar b$) are used, after fast DELPHES detector simulation and full event reconstruction through a kinematic fit, as a case study to test the observables' sensitivity to the $CP$ nature of the coupling. Confidence levels are presented as a function of the total integrated LHC luminosity for the case of exclusion of a pure $CP$-odd coupling against the Standard Model $CP$-even hypothesis. By using observables evaluated in the $t{\bar t} h$ system, the luminosity needed to directly probe the $CP$ properties of the top-quark Yukawa coupling at the High-Luminosity run of the LHC can be decreased by a few hundred inverse femtobarns, when compared to analyses that use observables in the laboratory rest frame. In addition, transverse momentum distributions of the $h$ boson and top quarks are found to provide no more discriminant power than a counting experiment.
1102.4693
Michael Kr\"amer
Philip Bechtle, Klaus Desch, Herbi K. Dreiner, Michael Kr\"amer, Ben O'Leary, Carsten Robens, Bj\"orn Sarrazin, and Peter Wienemann
What if the LHC does not find supersymmetry in the sqrt(s)=7 TeV run?
4 pages, 4 figures
Phys.Rev.D84:011701,2011
10.1103/PhysRevD.84.011701
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the implications for supersymmetry from an assumed absence of any signal in the first period of LHC data taking at 7 TeV center-of-mass energy and with 1 to 7 fb^(-1) of integrated luminosity. We consider the zero-lepton plus four jets and missing transverse energy signature, and perform a combined fit of low-energy measurements, the dark matter relic density constraint and potential LHC exclusions within a minimal supergravity model. A non-observation of supersymmetry in the first period of LHC data taking would still allow for an acceptable description of low-energy data and the dark matter relic density in terms of minimal supergravity models, but would exclude squarks and gluinos with masses below 1 TeV.
[ { "created": "Wed, 23 Feb 2011 09:18:39 GMT", "version": "v1" } ]
2011-08-09
[ [ "Bechtle", "Philip", "" ], [ "Desch", "Klaus", "" ], [ "Dreiner", "Herbi K.", "" ], [ "Krämer", "Michael", "" ], [ "O'Leary", "Ben", "" ], [ "Robens", "Carsten", "" ], [ "Sarrazin", "Björn", "" ], [ "Wienemann", "Peter", "" ] ]
We investigate the implications for supersymmetry from an assumed absence of any signal in the first period of LHC data taking at 7 TeV center-of-mass energy and with 1 to 7 fb^(-1) of integrated luminosity. We consider the zero-lepton plus four jets and missing transverse energy signature, and perform a combined fit of low-energy measurements, the dark matter relic density constraint and potential LHC exclusions within a minimal supergravity model. A non-observation of supersymmetry in the first period of LHC data taking would still allow for an acceptable description of low-energy data and the dark matter relic density in terms of minimal supergravity models, but would exclude squarks and gluinos with masses below 1 TeV.
0805.2296
Alexey Vladimirov
O.N.Soldatenko, A.N.Vall, A.A.Vladimirov
Unitarization of elastic amplitude on SO_mu(2.1) group
12 pages, 3 figures
Eur.Phys.J.A38:71-76,2008
10.1140/epja/i2008-10641-3
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We obtain the solution of the unitarity equation for the elastic processes in terms of the expansion coefficients of the amplitude as a function on the SO_mu(2.1) group. This approach is a generalization of the eikonal representation to the case of small impact parameters and large transverse momenta. We show how the unitarity relation is modified when the contributions of the backward scattering are taken into account. We discuss the simplest models of the profile functions in the following cases: full reflection, full absorption and the combination of these two cases.
[ { "created": "Thu, 15 May 2008 13:14:18 GMT", "version": "v1" } ]
2010-08-05
[ [ "Soldatenko", "O. N.", "" ], [ "Vall", "A. N.", "" ], [ "Vladimirov", "A. A.", "" ] ]
We obtain the solution of the unitarity equation for the elastic processes in terms of the expansion coefficients of the amplitude as a function on the SO_mu(2.1) group. This approach is a generalization of the eikonal representation to the case of small impact parameters and large transverse momenta. We show how the unitarity relation is modified when the contributions of the backward scattering are taken into account. We discuss the simplest models of the profile functions in the following cases: full reflection, full absorption and the combination of these two cases.
1101.6047
Ulrich Nierste
Jennifer Girrbach, Sebastian Jager, Markus Knopf, Waldemar Martens, Ulrich Nierste, Christian Scherrer, Soren Wiesenfeldt
Flavor Physics in an SO(10) Grand Unified Model
44 pages, 5 figures. Footnote and references added, minor changes, Fig. 2 corrected; journal version
JHEP 06 (2011) 044
10.1007/JHEP06(2011)044
TTP10-52, SFB/CPP-10-132
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In supersymmetric grand-unified models, the lepton mixing matrix can possibly affect flavor-changing transitions in the quark sector. We present a detailed analysis of a model proposed by Chang, Masiero and Murayama, in which the near-maximal atmospheric neutrino mixing angle governs large new b -> s transitions. Relating the supersymmetric low-energy parameters to seven new parameters of this SO(10) GUT model, we perform a correlated study of several flavor-changing neutral current (FCNC) processes. We find the current bound on B(tau -> mu gamma) more constraining than B(B -> X_s gamma). The LEP limit on the lightest Higgs boson mass implies an important lower bound on tan beta, which in turn limits the size of the new FCNC transitions. Remarkably, the combined analysis does not rule out large effects in B_s-B_s-bar mixing and we can easily accomodate the large CP phase in the B_s-B_s-bar system which has recently been inferred from a global analysis of CDF and DO data. The model predicts a particle spectrum which is different from the popular Constrained Minimal Supersymmetric Standard Model (CMSSM). B(tau -> mu gamma) enforces heavy masses, typically above 1 TeV, for the sfermions of the degenerate first two generations. However, the ratio of the third-generation and first-generation sfermion masses is smaller than in the CMSSM and a (dominantly right-handed) stop with mass below 500 GeV is possible.
[ { "created": "Mon, 31 Jan 2011 18:45:40 GMT", "version": "v1" }, { "created": "Tue, 31 May 2011 18:09:14 GMT", "version": "v2" }, { "created": "Thu, 23 Jun 2011 13:39:36 GMT", "version": "v3" } ]
2015-05-27
[ [ "Girrbach", "Jennifer", "" ], [ "Jager", "Sebastian", "" ], [ "Knopf", "Markus", "" ], [ "Martens", "Waldemar", "" ], [ "Nierste", "Ulrich", "" ], [ "Scherrer", "Christian", "" ], [ "Wiesenfeldt", "Soren", "" ] ]
In supersymmetric grand-unified models, the lepton mixing matrix can possibly affect flavor-changing transitions in the quark sector. We present a detailed analysis of a model proposed by Chang, Masiero and Murayama, in which the near-maximal atmospheric neutrino mixing angle governs large new b -> s transitions. Relating the supersymmetric low-energy parameters to seven new parameters of this SO(10) GUT model, we perform a correlated study of several flavor-changing neutral current (FCNC) processes. We find the current bound on B(tau -> mu gamma) more constraining than B(B -> X_s gamma). The LEP limit on the lightest Higgs boson mass implies an important lower bound on tan beta, which in turn limits the size of the new FCNC transitions. Remarkably, the combined analysis does not rule out large effects in B_s-B_s-bar mixing and we can easily accomodate the large CP phase in the B_s-B_s-bar system which has recently been inferred from a global analysis of CDF and DO data. The model predicts a particle spectrum which is different from the popular Constrained Minimal Supersymmetric Standard Model (CMSSM). B(tau -> mu gamma) enforces heavy masses, typically above 1 TeV, for the sfermions of the degenerate first two generations. However, the ratio of the third-generation and first-generation sfermion masses is smaller than in the CMSSM and a (dominantly right-handed) stop with mass below 500 GeV is possible.
hep-ph/9512293
Yongbin He
Yong-Bin He, Wei-Qin Chao and Chong-Shou Gao
Different Nuclear Dependence of $J/\psi$ and $\psi^{\prime}$ Production in p-A and A-p Collisions
12 pages(REVTeX), 3 uuencoded figures
null
null
CCAST-95-10
hep-ph
null
While presently available p-A data observe that the nuclear dependence of $J/\psi$ and $\psi^{\prime}$ production is the same within errors, we show that different nuclear dependence of $J/\psi$ and $\psi^{\prime}$ production in the kinematic region uncovered by the present p-A data can be predicted based on two different nuclear absorption scenarios. It is found that the predicted production ratio $\sigma (\psi^{\prime})/\sigma (J/\psi)$ at positive $x_F$ in A-p collisions is mainly determined by nuclear absorption, and hence allows direct experimental test of nuclear absorption scenarios.
[ { "created": "Wed, 13 Dec 1995 07:05:23 GMT", "version": "v1" } ]
2007-05-23
[ [ "He", "Yong-Bin", "" ], [ "Chao", "Wei-Qin", "" ], [ "Gao", "Chong-Shou", "" ] ]
While presently available p-A data observe that the nuclear dependence of $J/\psi$ and $\psi^{\prime}$ production is the same within errors, we show that different nuclear dependence of $J/\psi$ and $\psi^{\prime}$ production in the kinematic region uncovered by the present p-A data can be predicted based on two different nuclear absorption scenarios. It is found that the predicted production ratio $\sigma (\psi^{\prime})/\sigma (J/\psi)$ at positive $x_F$ in A-p collisions is mainly determined by nuclear absorption, and hence allows direct experimental test of nuclear absorption scenarios.
hep-ph/9610533
G. Wu
Guo-Hong Wu and John N. Ng (TRIUMF)
T-Violation in $K^+ \to \mu^+ \nu \gamma$ Decay And Supersymmetry
Revtex, 29 pages including 4 epsf figures
Phys.Rev.D55:2806-2816,1997
10.1103/PhysRevD.55.2806
TRI-PP-96-57
hep-ph hep-ex
null
Measurement of the transverse muon polarization $P^{\bot}_{\mu}$ in the $K^+ \rightarrow \mu^+\nu\gamma$ decay will be attempted for the first time at the ongoing KEK E246 experiment and also at a proposed BNL experiment. We provide a general analysis of how $P^{\bot}_{\mu}$ is sensitive to the physical $CP$-violating phases in new physics induced four-Fermi interactions, and then we calculate the dominant contributions to $P^{\bot}_{\mu}$ from squark family mixings in generic supersymmetric models. Estimates of the upper bounds on $P^{\bot}_{\mu}$ are also given. It is found that a supersymmetry-induced right-handed quark current from $W$ boson exchange gives an upper limit on $P^{\bot}_{\mu}$ as large as a few per cent, whereas with charged-Higgs-exchange induced pseudoscalar interaction, $P^{\bot}_{\mu}$ is no larger than a few tenths of a per cent. Possible correlations between the muon polarization measurements in $K^+ \rightarrow \mu^+\nu\gamma$ and $K^+ \rightarrow \pi^0\mu^+\nu$ decays are discussed, and distinctive patterns of this correlation from squark family-mixings and from the three-Higgs-doublet model are noted.
[ { "created": "Tue, 29 Oct 1996 20:20:26 GMT", "version": "v1" } ]
2014-11-17
[ [ "Wu", "Guo-Hong", "", "TRIUMF" ], [ "Ng", "John N.", "", "TRIUMF" ] ]
Measurement of the transverse muon polarization $P^{\bot}_{\mu}$ in the $K^+ \rightarrow \mu^+\nu\gamma$ decay will be attempted for the first time at the ongoing KEK E246 experiment and also at a proposed BNL experiment. We provide a general analysis of how $P^{\bot}_{\mu}$ is sensitive to the physical $CP$-violating phases in new physics induced four-Fermi interactions, and then we calculate the dominant contributions to $P^{\bot}_{\mu}$ from squark family mixings in generic supersymmetric models. Estimates of the upper bounds on $P^{\bot}_{\mu}$ are also given. It is found that a supersymmetry-induced right-handed quark current from $W$ boson exchange gives an upper limit on $P^{\bot}_{\mu}$ as large as a few per cent, whereas with charged-Higgs-exchange induced pseudoscalar interaction, $P^{\bot}_{\mu}$ is no larger than a few tenths of a per cent. Possible correlations between the muon polarization measurements in $K^+ \rightarrow \mu^+\nu\gamma$ and $K^+ \rightarrow \pi^0\mu^+\nu$ decays are discussed, and distinctive patterns of this correlation from squark family-mixings and from the three-Higgs-doublet model are noted.
hep-ph/9502303
Peter Suranyi
H.Hamidian (3), G. Semenoff (1), P. Suranyi (3), L.C.R. Wijewardhana (2, 3) ((1) University of British Columbia, (2) Uppsala University, (3) University of Cincinnati)
New Universality Classes for Quantum Critical Behavior
LaTeX, 9 pages, 1 tarred and uuencoded postscript figure. The new version contains information on the asymptotic dependence of the critical number of fermion species on $N_F$
Phys.Rev.Lett. 74 (1995) 4976-4979
10.1103/PhysRevLett.74.4976
null
hep-ph hep-th
null
We use the epsilon expansion to explore a new universality class of second order quantum phase transitions associated with a four-dimensional Yukawa field theory coupled to a traceless Hermitean matrix scalar field. We argue that this class includes four-fermi models in $2<D<4$ dimensions with $SU(N_F)\times U(N)$ symmetry and a U(N) scalar, $SU(N_F)$ iso-vector 4-fermi coupling. The epsilon expansion indicates that there is a second order phase transition for $N\geq N^*(N_F)$, where $N^*(N_F)\simeq.27N_F$ if $N_F\to\infty$.
[ { "created": "Tue, 14 Feb 1995 22:22:28 GMT", "version": "v1" }, { "created": "Wed, 15 Feb 1995 15:39:21 GMT", "version": "v2" }, { "created": "Thu, 27 Apr 1995 21:35:28 GMT", "version": "v3" } ]
2009-10-28
[ [ "Hamidian", "H.", "" ], [ "Semenoff", "G.", "" ], [ "Suranyi", "P.", "" ], [ "Wijewardhana", "L. C. R.", "" ] ]
We use the epsilon expansion to explore a new universality class of second order quantum phase transitions associated with a four-dimensional Yukawa field theory coupled to a traceless Hermitean matrix scalar field. We argue that this class includes four-fermi models in $2<D<4$ dimensions with $SU(N_F)\times U(N)$ symmetry and a U(N) scalar, $SU(N_F)$ iso-vector 4-fermi coupling. The epsilon expansion indicates that there is a second order phase transition for $N\geq N^*(N_F)$, where $N^*(N_F)\simeq.27N_F$ if $N_F\to\infty$.
2204.09029
Jose Alonso Carpio Dumler
Jose Alonso Carpio and Kohta Murase
Simulating neutrino echoes induced by secret neutrino interactions
20 pages, 8 figures. v2 is the version accepted for publication in JCAP
JCAP 02 (2023) 042
10.1088/1475-7516/2023/02/042
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New neutrino interactions beyond the Standard Model (BSM) have been of much interest in not only particle physics but also cosmology and astroparticle physics. We numerically investigate the time delay distribution of astrophysical neutrinos that interact with the cosmic neutrino background. Using the Monte Carlo method, we develop a framework that enables us to simulate the time-dependent energy spectra of high-energy neutrinos that experience even multiple scatterings en route and to handle the sharp increase in the cross section at the resonance energy. As an example, we focus on the case of secret neutrino interactions with a scalar mediator. While we find the excellent agreement between analytical and simulation results for small optical depths, our simulations enable us to study even optically-thick cases that are not described by the simplest analytic estimates. Our simulations are used to understand effects of cosmological redshifts, neutrino spectra and flavors. The developments will be useful for probing BSM neutrino interactions with not only current neutrino detectors such as IceCube and Super-Kamiokande but also future neutrino detectors such as IceCube-Gen2 and Hyper-Kamiokande.
[ { "created": "Tue, 19 Apr 2022 17:43:52 GMT", "version": "v1" }, { "created": "Wed, 18 Jan 2023 02:32:40 GMT", "version": "v2" } ]
2023-02-24
[ [ "Carpio", "Jose Alonso", "" ], [ "Murase", "Kohta", "" ] ]
New neutrino interactions beyond the Standard Model (BSM) have been of much interest in not only particle physics but also cosmology and astroparticle physics. We numerically investigate the time delay distribution of astrophysical neutrinos that interact with the cosmic neutrino background. Using the Monte Carlo method, we develop a framework that enables us to simulate the time-dependent energy spectra of high-energy neutrinos that experience even multiple scatterings en route and to handle the sharp increase in the cross section at the resonance energy. As an example, we focus on the case of secret neutrino interactions with a scalar mediator. While we find the excellent agreement between analytical and simulation results for small optical depths, our simulations enable us to study even optically-thick cases that are not described by the simplest analytic estimates. Our simulations are used to understand effects of cosmological redshifts, neutrino spectra and flavors. The developments will be useful for probing BSM neutrino interactions with not only current neutrino detectors such as IceCube and Super-Kamiokande but also future neutrino detectors such as IceCube-Gen2 and Hyper-Kamiokande.
hep-ph/0010205
Renard Fernand Michel
M. Beccaria, F.M. Renard and C. Verzegnassi
Top quark production at future lepton colliders in the asymptotic regime
20 pages and 13 figures. e-mail: renard@lpm.univ-montp2.fr
Phys.Rev. D63 (2001) 053013
10.1103/PhysRevD.63.053013
PM/00-39
hep-ph
null
The production of a tt(bar) pair from lepton-antilepton annihilation is considered for values of the center of mass energy much larger than the top mass, typically of the few TeV size. In this regime a number of simplifications occurs that allows to derive the leading asymptotic terms of various observables using the same theoretical description that was used for light quark production. Explicit examples are shown for the Standard Model and the Minimal Supersymmetric Standard Model cases.
[ { "created": "Wed, 18 Oct 2000 12:52:27 GMT", "version": "v1" } ]
2009-10-31
[ [ "Beccaria", "M.", "" ], [ "Renard", "F. M.", "" ], [ "Verzegnassi", "C.", "" ] ]
The production of a tt(bar) pair from lepton-antilepton annihilation is considered for values of the center of mass energy much larger than the top mass, typically of the few TeV size. In this regime a number of simplifications occurs that allows to derive the leading asymptotic terms of various observables using the same theoretical description that was used for light quark production. Explicit examples are shown for the Standard Model and the Minimal Supersymmetric Standard Model cases.
0710.0563
Stefano Nicotri
Stefano Nicotri
Newly observed charmed states: the case of X(3872)
LaTeX, 5 pages, 2 figures, talk given at IFAE 2007, Naples, Italy, 11-13 April
null
null
BARI-TH-07-573
hep-ph
null
I briefly review the properties of the hidden charm meson X(3872), discussing some puzzling aspects concerning its theoretical interpretation.
[ { "created": "Tue, 2 Oct 2007 16:40:11 GMT", "version": "v1" } ]
2007-10-03
[ [ "Nicotri", "Stefano", "" ] ]
I briefly review the properties of the hidden charm meson X(3872), discussing some puzzling aspects concerning its theoretical interpretation.
2002.05174
Oleksii Matsedonskyi
Oleksii Matsedonskyi and Geraldine Servant
High-Temperature Electroweak Symmetry Non-Restoration from New Fermions and Implications for Baryogenesis
23 pages, 8 figures, v2: published in JHEP with minor corrections
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The strength of electroweak symmetry breaking may substantially differ in the early Universe compared to the present day value. In the Standard Model, the Higgs vacuum expectation value (vev) vanishes and electroweak symmetry gets restored at temperatures above $\sim 160$ GeV due to the Higgs field interactions with the high-temperature plasma. It was however shown that new light singlet scalar fields may change this behaviour. The key feature is the non-standard dependence on the Higgs vev of the new particles mass which can vanish at large Higgs vev, inducing a negative correction to the Higgs thermal mass, leading to electroweak symmetry non-restoration at high temperature. We show that such an effect can also be induced by new singlet fermions which on the other hand have the advantage of not producing unstable directions in the scalar potential at tree level, nor bringing additional severe hierarchy problems. As temperature drops, such a high-temperature breaking phase may continuously evolve into the zero-temperature breaking phase or the two phases can be separated by a temporary phase of restored symmetry. We discuss how our construction can naturally arise in motivated models of new physics, such as Composite Higgs. This is particularly relevant for baryogenesis, as it opens a whole class of possibilities in which the baryon asymmetry can be produced during a high temperature phase transition, while not being erased later by sphalerons.
[ { "created": "Wed, 12 Feb 2020 19:00:13 GMT", "version": "v1" }, { "created": "Tue, 1 Sep 2020 10:49:07 GMT", "version": "v2" } ]
2020-09-02
[ [ "Matsedonskyi", "Oleksii", "" ], [ "Servant", "Geraldine", "" ] ]
The strength of electroweak symmetry breaking may substantially differ in the early Universe compared to the present day value. In the Standard Model, the Higgs vacuum expectation value (vev) vanishes and electroweak symmetry gets restored at temperatures above $\sim 160$ GeV due to the Higgs field interactions with the high-temperature plasma. It was however shown that new light singlet scalar fields may change this behaviour. The key feature is the non-standard dependence on the Higgs vev of the new particles mass which can vanish at large Higgs vev, inducing a negative correction to the Higgs thermal mass, leading to electroweak symmetry non-restoration at high temperature. We show that such an effect can also be induced by new singlet fermions which on the other hand have the advantage of not producing unstable directions in the scalar potential at tree level, nor bringing additional severe hierarchy problems. As temperature drops, such a high-temperature breaking phase may continuously evolve into the zero-temperature breaking phase or the two phases can be separated by a temporary phase of restored symmetry. We discuss how our construction can naturally arise in motivated models of new physics, such as Composite Higgs. This is particularly relevant for baryogenesis, as it opens a whole class of possibilities in which the baryon asymmetry can be produced during a high temperature phase transition, while not being erased later by sphalerons.
hep-ph/0403210
Shi-Lin Zhu
A. Zhang, Y.-R. Liu, P.-Z. Huang, W.-Z. Deng, X.-L. Chen, Shi-Lin Zhu
$J^P={1/2}^-$ Pentaquarks in Jaffe and Wilczek's Diquark Model
null
High Energy Phys.Nucl.Phys. 29 (2005) 250
null
null
hep-ph hep-ex hep-lat nucl-ex nucl-th
null
If Jaffe and Wilczek's diquark picture for $\Theta_5$ pentaquark is correct, there should also exist a $SU_F$(3) pentaquark octet and singlet with no orbital excitation between the diquark pair, hence $J^P={1/2}^-$. These states are lighter than the $\Theta_5$ anti-decuplet and lie close to the orbitally excited (L=1) three-quark states in the conventional quark model. We calculate their masses and magnetic moments and discuss their possible strong decays using the chiral Lagrangian formalism. Among them two pentaquarks with nucleon quantum numbers may be narrow. Selection rules of strong decays are derived. We propose the experimental search of these nine additional $J^P={1/2}^-$ baryon states. Especially there are two additional $J^P={1/2}^-$ $\Lambda$ baryons around $\Lambda (1405)$. We also discuss the interesting possibility of interpreting $\Lambda (1405)$ as a pentaquark. The presence of these additional states will provide strong support of the diquark picture for the pentaquarks. If future experimental searches fail, one has to re-evaluate the relevance of this picture for the pentaquarks.
[ { "created": "Fri, 19 Mar 2004 13:09:06 GMT", "version": "v1" }, { "created": "Sat, 20 Mar 2004 06:38:12 GMT", "version": "v2" }, { "created": "Tue, 23 Mar 2004 00:30:22 GMT", "version": "v3" } ]
2007-05-23
[ [ "Zhang", "A.", "" ], [ "Liu", "Y. -R.", "" ], [ "Huang", "P. -Z.", "" ], [ "Deng", "W. -Z.", "" ], [ "Chen", "X. -L.", "" ], [ "Zhu", "Shi-Lin", "" ] ]
If Jaffe and Wilczek's diquark picture for $\Theta_5$ pentaquark is correct, there should also exist a $SU_F$(3) pentaquark octet and singlet with no orbital excitation between the diquark pair, hence $J^P={1/2}^-$. These states are lighter than the $\Theta_5$ anti-decuplet and lie close to the orbitally excited (L=1) three-quark states in the conventional quark model. We calculate their masses and magnetic moments and discuss their possible strong decays using the chiral Lagrangian formalism. Among them two pentaquarks with nucleon quantum numbers may be narrow. Selection rules of strong decays are derived. We propose the experimental search of these nine additional $J^P={1/2}^-$ baryon states. Especially there are two additional $J^P={1/2}^-$ $\Lambda$ baryons around $\Lambda (1405)$. We also discuss the interesting possibility of interpreting $\Lambda (1405)$ as a pentaquark. The presence of these additional states will provide strong support of the diquark picture for the pentaquarks. If future experimental searches fail, one has to re-evaluate the relevance of this picture for the pentaquarks.
hep-ph/9702313
Charles Picciotto
C. E. Picciotto
K+ to pi-mu+mu+ and doubly-charged Higgs
8 pages, RevTex, Figure1 is PS
Phys.Rev. D56 (1997) 1612-1614
10.1103/PhysRevD.56.1612
null
hep-ph
null
The rate for the lepton-number-violating decay K+ to pi- mu+mu+ is calculated in a model which incorporates doubly-charged Higgs bosons. We find that for reasonable values of the parameters the decay branching ratio may be as large as 2E-16. Although this is a discouragingly small number, it is of the same order of magnitude as the rate mediated by massive Majorana neutrinos.
[ { "created": "Wed, 12 Feb 1997 09:17:28 GMT", "version": "v1" } ]
2009-10-30
[ [ "Picciotto", "C. E.", "" ] ]
The rate for the lepton-number-violating decay K+ to pi- mu+mu+ is calculated in a model which incorporates doubly-charged Higgs bosons. We find that for reasonable values of the parameters the decay branching ratio may be as large as 2E-16. Although this is a discouragingly small number, it is of the same order of magnitude as the rate mediated by massive Majorana neutrinos.
0903.4345
Keith Hamilton
Keith Hamilton, Peter Richardson, Jon Tully
A Positive-Weight Next-to-Leading Order Monte Carlo Simulation for Higgs Boson Production
43 pages. Citations added and Tevatron limits updated (JHEP version)
JHEP 0904:116,2009
10.1088/1126-6708/2009/04/116
MCNET/09/08, IPPP/09/20
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article we describe simulations of Higgs boson production via the gluon fusion and Higgs-strahlung processes, using the positive weight next-to-leading-order (NLO) matching scheme, POWHEG, in the Herwig++ 2.3 event generator. This formalism consistently incorporates the full NLO corrections to these processes within the parton shower simulation, without the production of negative weight events. These simulations include a full implementation of the truncated shower required to correctly model soft emissions in an angular-ordered parton shower. We present a thorough validation of these simulations, comparing them to other methods and calculations. The results obtained for the gluon fusion process corroborate, and provide detailed explanations for, findings reported by Alioli et al (arXiv:0812.0578) using an independent POWHEG simulation, neglecting truncated shower effects, released at the same time as our code.
[ { "created": "Wed, 25 Mar 2009 17:51:15 GMT", "version": "v1" }, { "created": "Tue, 31 Mar 2009 14:59:58 GMT", "version": "v2" }, { "created": "Mon, 11 May 2009 13:18:35 GMT", "version": "v3" } ]
2009-05-20
[ [ "Hamilton", "Keith", "" ], [ "Richardson", "Peter", "" ], [ "Tully", "Jon", "" ] ]
In this article we describe simulations of Higgs boson production via the gluon fusion and Higgs-strahlung processes, using the positive weight next-to-leading-order (NLO) matching scheme, POWHEG, in the Herwig++ 2.3 event generator. This formalism consistently incorporates the full NLO corrections to these processes within the parton shower simulation, without the production of negative weight events. These simulations include a full implementation of the truncated shower required to correctly model soft emissions in an angular-ordered parton shower. We present a thorough validation of these simulations, comparing them to other methods and calculations. The results obtained for the gluon fusion process corroborate, and provide detailed explanations for, findings reported by Alioli et al (arXiv:0812.0578) using an independent POWHEG simulation, neglecting truncated shower effects, released at the same time as our code.
1109.1375
Binur Shaykhatdenov
A.V. Kotikov, V.G. Krivokhizhin, B.G. Shaikhatdenov
Effect of the analytic and frozen coupling constants in QCD up to NNLO from DIS data
28pp, 7 figs, contribution to the Proceedings of XLV PNPI Winter School held in Roschino (Russia) on 28 feb - 5 March, 2011
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We give a short review of our recent analysis [1] of the deep inelastic scattering data (provided by BCDMS, SLAC, NMC) on F2 structure function in the non-singlet approximation with up to next-to-next-to-leading-order accuracy and analytic and frozen modifications of the strong coupling constant featuring no unphysical singularity (the Landau pole). Improvement of agreement between theory and experiment, with respect to the case of the standard perturbative definition of the strong coupling constant considered recently in [2], was observed.
[ { "created": "Wed, 7 Sep 2011 07:41:43 GMT", "version": "v1" } ]
2011-09-08
[ [ "Kotikov", "A. V.", "" ], [ "Krivokhizhin", "V. G.", "" ], [ "Shaikhatdenov", "B. G.", "" ] ]
We give a short review of our recent analysis [1] of the deep inelastic scattering data (provided by BCDMS, SLAC, NMC) on F2 structure function in the non-singlet approximation with up to next-to-next-to-leading-order accuracy and analytic and frozen modifications of the strong coupling constant featuring no unphysical singularity (the Landau pole). Improvement of agreement between theory and experiment, with respect to the case of the standard perturbative definition of the strong coupling constant considered recently in [2], was observed.
2403.03972
Marianne Moore
Marianne Moore and Tracy R. Slatyer
On the cosmology and terrestrial signals of sexaquark dark matter
27 pages + appendices, 14 figures, v2: version accepted for publication
Phys. Rev. D 110 (2024) 2, 023515
10.1103/PhysRevD.110.023515
MIT-CTP/5685
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the hypothesis that sexaquarks, hypothetical stable six-quark states, could be a significant component of the dark matter. We expand on previous studies of sexaquark cosmology, accounting for the possibility that some relevant interaction cross sections might be strongly suppressed below expectations based on dimensional analysis. We update direct-detection constraints on stable sexaquarks comprising a subdominant fraction of the dark matter, as well as limits on the annihilation of an antisexaquark component from Super-Kamiokande. We argue that the scenario where sexaquarks comprise a $O(1)$ fraction of the dark matter would require either a suppression of $O(10^{-19})$ in sexaquark interactions with baryons, combined with a very high yield of net sexaquark number from the quark-hadron transition, or else a very strong suppression of the cross section for antisexaquark annihilation on nucleons (24+ orders of magnitude below the QCD scale). Independently, we find that a sexaquark component comprising more than $O(10^{-3})$ of the dark matter can be excluded from direct-detection bounds, unless its scattering cross section is severely suppressed compared to the expected scale of strong and even electromagnetic interactions.
[ { "created": "Wed, 6 Mar 2024 19:00:00 GMT", "version": "v1" }, { "created": "Thu, 25 Jul 2024 04:00:31 GMT", "version": "v2" } ]
2024-07-26
[ [ "Moore", "Marianne", "" ], [ "Slatyer", "Tracy R.", "" ] ]
We investigate the hypothesis that sexaquarks, hypothetical stable six-quark states, could be a significant component of the dark matter. We expand on previous studies of sexaquark cosmology, accounting for the possibility that some relevant interaction cross sections might be strongly suppressed below expectations based on dimensional analysis. We update direct-detection constraints on stable sexaquarks comprising a subdominant fraction of the dark matter, as well as limits on the annihilation of an antisexaquark component from Super-Kamiokande. We argue that the scenario where sexaquarks comprise a $O(1)$ fraction of the dark matter would require either a suppression of $O(10^{-19})$ in sexaquark interactions with baryons, combined with a very high yield of net sexaquark number from the quark-hadron transition, or else a very strong suppression of the cross section for antisexaquark annihilation on nucleons (24+ orders of magnitude below the QCD scale). Independently, we find that a sexaquark component comprising more than $O(10^{-3})$ of the dark matter can be excluded from direct-detection bounds, unless its scattering cross section is severely suppressed compared to the expected scale of strong and even electromagnetic interactions.
0905.4347
Abdulkadir Senol
O. Cakir, A. Senol and A. T. Tasci
Single Production of Fourth Family $t'$ Quarks at LHeC
9 pages, 8 figures
Europhys.Lett.88:11002,2009
10.1209/0295-5075/88/11002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the single production of fourth-family $t'$ quarks via the process $ep\to t'\nu$ at Large Hadron electron Collider (LHeC). We calculate the background and signal cross sections for the mass range 300-800 GeV. It is shown that the LHeC can discover single $t'$ quark up to the mass of 800 GeV for the optimized mixing parameters.
[ { "created": "Wed, 27 May 2009 07:31:15 GMT", "version": "v1" } ]
2009-10-26
[ [ "Cakir", "O.", "" ], [ "Senol", "A.", "" ], [ "Tasci", "A. T.", "" ] ]
We study the single production of fourth-family $t'$ quarks via the process $ep\to t'\nu$ at Large Hadron electron Collider (LHeC). We calculate the background and signal cross sections for the mass range 300-800 GeV. It is shown that the LHeC can discover single $t'$ quark up to the mass of 800 GeV for the optimized mixing parameters.
hep-ph/9911542
Stephen J. Puglia
S.J. Puglia, M.J. Ramsey-Musolf
Baryon Octet magnetic moments in $\chi$PT: More on the importance of the Decuplet
17 pages, 2 figures. Includes axodraw.sty needed for figures Minor typos corrected
Phys.Rev. D62 (2000) 034010
10.1103/PhysRevD.62.034010
null
hep-ph
null
We address the impact of treating the decuplet of spin-3/2 baryons as an explicit degree of freedom in the chiral expansion of the magnetic moments of the octet of spin-1/2 baryons. We carry out a complete calculation of the octet moments to O(1/\lamchic), including decuplet contributions to the chiral loops. In contrast to results of previous analyses, we find that inclusion of the decuplet preserves the convergence behavior of the chiral expansion implied by power counting arguments.
[ { "created": "Tue, 30 Nov 1999 23:49:45 GMT", "version": "v1" }, { "created": "Wed, 15 Dec 1999 19:37:38 GMT", "version": "v2" } ]
2009-10-31
[ [ "Puglia", "S. J.", "" ], [ "Ramsey-Musolf", "M. J.", "" ] ]
We address the impact of treating the decuplet of spin-3/2 baryons as an explicit degree of freedom in the chiral expansion of the magnetic moments of the octet of spin-1/2 baryons. We carry out a complete calculation of the octet moments to O(1/\lamchic), including decuplet contributions to the chiral loops. In contrast to results of previous analyses, we find that inclusion of the decuplet preserves the convergence behavior of the chiral expansion implied by power counting arguments.
hep-ph/9405384
null
Alessandro Ballestrero, Ezio Maina and Stefano Moretti (U. of Torino, Italy)
Heavy Quark Production at $e^+ e^-$ Colliders in Multijet Events and a New Method of Computing Helicity Amplitudes
LateX, 6 pag + 2 figs uucompressed
null
null
null
hep-ph
null
Heavy quark production in multijet events at $e^+e^-$ colliders is studied at tree level. Total production rates are given and compared with the corresponding results for massless quarks. A new method of computing helicity amplitudes is briefly sketched. Talk presented at the XXIXth Rencontres de Moriond, QCD and High Energy Hadronic Interactions, Meribel, France, March 19-26 1994.
[ { "created": "Thu, 26 May 1994 09:09:40 GMT", "version": "v1" } ]
2009-09-25
[ [ "Ballestrero", "Alessandro", "", "U. of Torino,\n Italy" ], [ "Maina", "Ezio", "", "U. of Torino,\n Italy" ], [ "Moretti", "Stefano", "", "U. of Torino,\n Italy" ] ]
Heavy quark production in multijet events at $e^+e^-$ colliders is studied at tree level. Total production rates are given and compared with the corresponding results for massless quarks. A new method of computing helicity amplitudes is briefly sketched. Talk presented at the XXIXth Rencontres de Moriond, QCD and High Energy Hadronic Interactions, Meribel, France, March 19-26 1994.
1806.08361
Jaime Hern\'andez-S\'anchez Dr.
S.P. Das, J. Hernandez-Sanchez, S. Moretti, A. Rosado
Prospects for discovering a light charged Higgs boson within the NMSSM at the FCC-eh collider
16 pages, 9 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the prospects of observing relatively light charged Higgs bosons ($h^{\pm}$) in their decays via $h^{-} \to s \bar c + s \bar u$ at the upcoming Future Circular Collider in hadron-electron mode (FCC-eh) with $\sqrt s \approx 3.5$ TeV. Assuming that the intermediate Higgs boson ($h_2$) is Standard Model (SM)-like, we study the production of $e^- b \to \nu_e h^{-} b$ (also $b$ could be $\bar b$ in both initial and final states) in the framework of the Next-to-Minimal Supersymmetric Standard Model (NMSSM). We consider constraints from Dark Matter (DM), super-particle and the Higgs boson data. The charged Higgs boson decays into light flavors leads to a three-jets with missing transverse energy signal with one $b$-tagged jet. Our results show that light charged Higgs bosons with mass close to, e.g., 114(121) GeV have the maximal significance of 3.2(1.8)$\sigma$, upon using normal cut based selections and after 1 ab$^{-1}$ of luminosity. However, we further adopt an optimization technique to enhance the latter to 4.4 (2.2)$\sigma$, respectively.
[ { "created": "Thu, 21 Jun 2018 18:00:01 GMT", "version": "v1" } ]
2018-06-25
[ [ "Das", "S. P.", "" ], [ "Hernandez-Sanchez", "J.", "" ], [ "Moretti", "S.", "" ], [ "Rosado", "A.", "" ] ]
We analyze the prospects of observing relatively light charged Higgs bosons ($h^{\pm}$) in their decays via $h^{-} \to s \bar c + s \bar u$ at the upcoming Future Circular Collider in hadron-electron mode (FCC-eh) with $\sqrt s \approx 3.5$ TeV. Assuming that the intermediate Higgs boson ($h_2$) is Standard Model (SM)-like, we study the production of $e^- b \to \nu_e h^{-} b$ (also $b$ could be $\bar b$ in both initial and final states) in the framework of the Next-to-Minimal Supersymmetric Standard Model (NMSSM). We consider constraints from Dark Matter (DM), super-particle and the Higgs boson data. The charged Higgs boson decays into light flavors leads to a three-jets with missing transverse energy signal with one $b$-tagged jet. Our results show that light charged Higgs bosons with mass close to, e.g., 114(121) GeV have the maximal significance of 3.2(1.8)$\sigma$, upon using normal cut based selections and after 1 ab$^{-1}$ of luminosity. However, we further adopt an optimization technique to enhance the latter to 4.4 (2.2)$\sigma$, respectively.
1502.03541
Hyung Do Kim
Dongjin Chway, Tae Hyun Jung and Hyung Do Kim
Unstable Particles near Threshold
5 pages, 4 figures
null
10.3938/jkps.69.16
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore physics of unstable particles when mother particle mass is around the sum of its daughter particle masses. In this case, the conventional wave function renormalization factor is ill-defined. We propose a simple resolution of the threshold singularity problem which still allows the use of narrow width approximation by defining branching ratio in terms of spectral density. The resonance peak and shape is different for different decay channels and no single decay width can be assigned to the unstable particles. Non-exponential decay happens in all time scales.
[ { "created": "Thu, 12 Feb 2015 05:22:18 GMT", "version": "v1" } ]
2016-08-03
[ [ "Chway", "Dongjin", "" ], [ "Jung", "Tae Hyun", "" ], [ "Kim", "Hyung Do", "" ] ]
We explore physics of unstable particles when mother particle mass is around the sum of its daughter particle masses. In this case, the conventional wave function renormalization factor is ill-defined. We propose a simple resolution of the threshold singularity problem which still allows the use of narrow width approximation by defining branching ratio in terms of spectral density. The resonance peak and shape is different for different decay channels and no single decay width can be assigned to the unstable particles. Non-exponential decay happens in all time scales.
hep-ph/9804314
Zhukovsky Vladimir
P.A. Eminov, K.V. Zhukovskii, K.G. Levtchenko
Production of Higgs with Z--boson by an electron in external fields
17 pages, LaTeX, 1 eps figure
null
null
Preprint MSU Faculty of Physics 7/98
hep-ph
null
The rate of associative production of Higgs and $Z$--bosons by charged leptons in the field of a plane electromagnetic wave of arbitrary intensity and in the constant crossed field is obtained. The cross section is examined as a function of particle energies and external field intensities for various values of the Higgs boson mass. It is shown, that the photoproduction cross section increases logarithmically at super high energies up to the values, that essentially exceed the cross section of the reaction $e^+e^-\to ZH,$ which, at present, is considered as the most probable channel of Higgs boson production.
[ { "created": "Fri, 17 Apr 1998 10:16:30 GMT", "version": "v1" } ]
2007-05-23
[ [ "Eminov", "P. A.", "" ], [ "Zhukovskii", "K. V.", "" ], [ "Levtchenko", "K. G.", "" ] ]
The rate of associative production of Higgs and $Z$--bosons by charged leptons in the field of a plane electromagnetic wave of arbitrary intensity and in the constant crossed field is obtained. The cross section is examined as a function of particle energies and external field intensities for various values of the Higgs boson mass. It is shown, that the photoproduction cross section increases logarithmically at super high energies up to the values, that essentially exceed the cross section of the reaction $e^+e^-\to ZH,$ which, at present, is considered as the most probable channel of Higgs boson production.
hep-ph/0210374
Borut Bajc
Borut Bajc, Pavel Fileviez Perez and Goran Senjanovic
Minimal supersymmetric SU(5) theory and proton decay: where do we stand?
latex, 9 pages, talk given by B.B. at Beyond the Desert 02, Oulu, Finland, 2-7 June 2002, to appear in the proceedings
null
null
null
hep-ph
null
We review the situation regarding d=5 proton decay in the minimal supersymmetric SU(5) GUT. The minimal theory is defined as the theory with the minimal matter and Higgs content all the way up to the Planck scale; of course, this allows for the possible presence of Planck induced physics. It can be said that either higher dimensional operators must be present or/and some fine-tuning of O(1%) of the Higgs mass must be tolerated in order to save the theory.
[ { "created": "Mon, 28 Oct 2002 12:22:16 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bajc", "Borut", "" ], [ "Perez", "Pavel Fileviez", "" ], [ "Senjanovic", "Goran", "" ] ]
We review the situation regarding d=5 proton decay in the minimal supersymmetric SU(5) GUT. The minimal theory is defined as the theory with the minimal matter and Higgs content all the way up to the Planck scale; of course, this allows for the possible presence of Planck induced physics. It can be said that either higher dimensional operators must be present or/and some fine-tuning of O(1%) of the Higgs mass must be tolerated in order to save the theory.
hep-ph/9908249
Judith McGovern
Judith A. McGovern and Michael C. Birse
Nothing anomalous about two-loop HBCPT: consistency with the LET for spin-dependent Compton scattering
Minor typos corrected. 7 pages RevTeX, 1 eps figure
Phys.Rev.D61:017503,2000
10.1103/PhysRevD.61.017503
null
hep-ph nucl-th
null
The leading order contributions of processes involving anomalous pion-photon vertices to forward spin-dependent Compton scattering from nucleons are considered in heavy-baryon chiral perturbation theory. These all involve the exchange of three pions between one or two photons and the nucleon, and hence are two-loop processes. We find that the sum of these processes vanishes in the manner predicted by the low energy theorem of Low, Gell-Mann and Goldberger as the photon energy goes to zero. This provides the first consistency test of two-loop HBCPT.
[ { "created": "Wed, 4 Aug 1999 11:02:24 GMT", "version": "v1" }, { "created": "Thu, 23 Dec 1999 14:19:08 GMT", "version": "v2" } ]
2008-11-26
[ [ "McGovern", "Judith A.", "" ], [ "Birse", "Michael C.", "" ] ]
The leading order contributions of processes involving anomalous pion-photon vertices to forward spin-dependent Compton scattering from nucleons are considered in heavy-baryon chiral perturbation theory. These all involve the exchange of three pions between one or two photons and the nucleon, and hence are two-loop processes. We find that the sum of these processes vanishes in the manner predicted by the low energy theorem of Low, Gell-Mann and Goldberger as the photon energy goes to zero. This provides the first consistency test of two-loop HBCPT.
1811.12482
Knut Dundas Mor{\aa}
E. Aprile, J. Aalbers, F. Agostini, M. Alfonsi, L. Althueser, F. D. Amaro, M. Anthony, V. C. Antochi, F. Arneodo, L. Baudis, B. Bauermeister, M. L. Benabderrahmane, T. Berger, P. A. Breur, A. Brown, A. Brown, E. Brown, S. Bruenner, G. Bruno, R. Budnik, C. Capelli, J. M. R. Cardoso, D. Cichon, D. Coderre, A. P. Colijn, J. Conrad, J. P. Cussonneau, M. P. Decowski, P. de Perio, P. Di Gangi, A. Di Giovanni, S. Diglio, A. Elykov, G. Eurin, J. Fei, A. D. Ferella, A. Fieguth, W. Fulgione, A. Gallo Rosso, M. Galloway, F. Gao, M. Garbini, L. Grandi, Z. Greene, C. Hasterok, E. Hogenbirk, J. Howlett, M. Iacovacci, R. Itay, F. Joerg, B. Kaminsky, S. Kazama, A. Kish, G. Koltman, A. Kopec, H. Landsman, R. F. Lang, L. Levinson, Q. Lin, S. Lindemann, M. Lindner, F. Lombardi, J. A. M. Lopes, E. L\'opez Fune, C. Macolino, J. Mahlstedt, A. Manfredini, F. Marignetti, T. Marrod\'an Undagoitia, J. Masbou, D. Masson, S. Mastroianni, M. Messina, K. Micheneau, K. Miller, A. Molinario, K. Mor{\aa}, M. Murra, J. Naganoma, K. Ni, U. Oberlack, K. Odgers, B. Pelssers, F. Piastra, J. Pienaar, V. Pizzella, G. Plante, R. Podviianiuk, N. Priel, H. Qiu, D. Ram\'irez Garc\'ia, S. Reichard, B. Riedel, A. Rizzo, A. Rocchetti, N. Rupp, J. M. F. dos Santos, G. Sartorelli, N. \v{S}ar\v{c}evi\'c, M. Scheibelhut, S. Schindler, J. Schreiner, D. Schulte, M. Schumann, L. Scotto Lavina, M. Selvi, P. Shagin, E. Shockley, M. Silva, H. Simgen, C. Therreau, D. Thers, F. Toschi, G. Trinchero, C. Tunnell, N. Upole, M. Vargas, O. Wack, H. Wang, Z. Wang, Y. Wei, C. Weinheimer, C. Wittweg, J. Wulf, J. Ye, Y. Zhang, T. Zhu, J. P. Zopounidis, M. Hoferichter, P. Klos, J. Men\'endez, A. Schwenk
First results on the scalar WIMP-pion coupling, using the XENON1T experiment
null
Phys. Rev. Lett. 122, 071301 (2019)
10.1103/PhysRevLett.122.071301
INT-PUB-18-058
hep-ph astro-ph.CO hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present first results on the scalar WIMP-pion coupling from 1 t$\times$yr of exposure with the XENON1T experiment. This interaction is generated when the WIMP couples to a virtual pion exchanged between the nucleons in a nucleus. In contrast to most non-relativistic operators, these pion-exchange currents can be coherently enhanced by the total number of nucleons, and therefore may dominate in scenarios where spin-independent WIMP-nucleon interactions are suppressed. Moreover, for natural values of the couplings, they dominate over the spin-dependent channel due to their coherence in the nucleus. Using the signal model of this new WIMP-pion channel, no significant excess is found, leading to an upper limit cross section of $6.4\times10^{-46}$ cm$^2$ (90 % confidence level) at 30 GeV/c$^2$ WIMP mass.
[ { "created": "Thu, 29 Nov 2018 20:57:18 GMT", "version": "v1" }, { "created": "Fri, 22 Feb 2019 13:16:54 GMT", "version": "v2" } ]
2019-02-25
[ [ "Aprile", "E.", "" ], [ "Aalbers", "J.", "" ], [ "Agostini", "F.", "" ], [ "Alfonsi", "M.", "" ], [ "Althueser", "L.", "" ], [ "Amaro", "F. D.", "" ], [ "Anthony", "M.", "" ], [ "Antochi", "V. C.", "" ], [ "Arneodo", "F.", "" ], [ "Baudis", "L.", "" ], [ "Bauermeister", "B.", "" ], [ "Benabderrahmane", "M. L.", "" ], [ "Berger", "T.", "" ], [ "Breur", "P. A.", "" ], [ "Brown", "A.", "" ], [ "Brown", "A.", "" ], [ "Brown", "E.", "" ], [ "Bruenner", "S.", "" ], [ "Bruno", "G.", "" ], [ "Budnik", "R.", "" ], [ "Capelli", "C.", "" ], [ "Cardoso", "J. M. R.", "" ], [ "Cichon", "D.", "" ], [ "Coderre", "D.", "" ], [ "Colijn", "A. P.", "" ], [ "Conrad", "J.", "" ], [ "Cussonneau", "J. P.", "" ], [ "Decowski", "M. P.", "" ], [ "de Perio", "P.", "" ], [ "Di Gangi", "P.", "" ], [ "Di Giovanni", "A.", "" ], [ "Diglio", "S.", "" ], [ "Elykov", "A.", "" ], [ "Eurin", "G.", "" ], [ "Fei", "J.", "" ], [ "Ferella", "A. D.", "" ], [ "Fieguth", "A.", "" ], [ "Fulgione", "W.", "" ], [ "Rosso", "A. Gallo", "" ], [ "Galloway", "M.", "" ], [ "Gao", "F.", "" ], [ "Garbini", "M.", "" ], [ "Grandi", "L.", "" ], [ "Greene", "Z.", "" ], [ "Hasterok", "C.", "" ], [ "Hogenbirk", "E.", "" ], [ "Howlett", "J.", "" ], [ "Iacovacci", "M.", "" ], [ "Itay", "R.", "" ], [ "Joerg", "F.", "" ], [ "Kaminsky", "B.", "" ], [ "Kazama", "S.", "" ], [ "Kish", "A.", "" ], [ "Koltman", "G.", "" ], [ "Kopec", "A.", "" ], [ "Landsman", "H.", "" ], [ "Lang", "R. F.", "" ], [ "Levinson", "L.", "" ], [ "Lin", "Q.", "" ], [ "Lindemann", "S.", "" ], [ "Lindner", "M.", "" ], [ "Lombardi", "F.", "" ], [ "Lopes", "J. A. M.", "" ], [ "Fune", "E. López", "" ], [ "Macolino", "C.", "" ], [ "Mahlstedt", "J.", "" ], [ "Manfredini", "A.", "" ], [ "Marignetti", "F.", "" ], [ "Undagoitia", "T. Marrodán", "" ], [ "Masbou", "J.", "" ], [ "Masson", "D.", "" ], [ "Mastroianni", "S.", "" ], [ "Messina", "M.", "" ], [ "Micheneau", "K.", "" ], [ "Miller", "K.", "" ], [ "Molinario", "A.", "" ], [ "Morå", "K.", "" ], [ "Murra", "M.", "" ], [ "Naganoma", "J.", "" ], [ "Ni", "K.", "" ], [ "Oberlack", "U.", "" ], [ "Odgers", "K.", "" ], [ "Pelssers", "B.", "" ], [ "Piastra", "F.", "" ], [ "Pienaar", "J.", "" ], [ "Pizzella", "V.", "" ], [ "Plante", "G.", "" ], [ "Podviianiuk", "R.", "" ], [ "Priel", "N.", "" ], [ "Qiu", "H.", "" ], [ "García", "D. Ramírez", "" ], [ "Reichard", "S.", "" ], [ "Riedel", "B.", "" ], [ "Rizzo", "A.", "" ], [ "Rocchetti", "A.", "" ], [ "Rupp", "N.", "" ], [ "Santos", "J. M. F. dos", "" ], [ "Sartorelli", "G.", "" ], [ "Šarčević", "N.", "" ], [ "Scheibelhut", "M.", "" ], [ "Schindler", "S.", "" ], [ "Schreiner", "J.", "" ], [ "Schulte", "D.", "" ], [ "Schumann", "M.", "" ], [ "Lavina", "L. Scotto", "" ], [ "Selvi", "M.", "" ], [ "Shagin", "P.", "" ], [ "Shockley", "E.", "" ], [ "Silva", "M.", "" ], [ "Simgen", "H.", "" ], [ "Therreau", "C.", "" ], [ "Thers", "D.", "" ], [ "Toschi", "F.", "" ], [ "Trinchero", "G.", "" ], [ "Tunnell", "C.", "" ], [ "Upole", "N.", "" ], [ "Vargas", "M.", "" ], [ "Wack", "O.", "" ], [ "Wang", "H.", "" ], [ "Wang", "Z.", "" ], [ "Wei", "Y.", "" ], [ "Weinheimer", "C.", "" ], [ "Wittweg", "C.", "" ], [ "Wulf", "J.", "" ], [ "Ye", "J.", "" ], [ "Zhang", "Y.", "" ], [ "Zhu", "T.", "" ], [ "Zopounidis", "J. P.", "" ], [ "Hoferichter", "M.", "" ], [ "Klos", "P.", "" ], [ "Menéndez", "J.", "" ], [ "Schwenk", "A.", "" ] ]
We present first results on the scalar WIMP-pion coupling from 1 t$\times$yr of exposure with the XENON1T experiment. This interaction is generated when the WIMP couples to a virtual pion exchanged between the nucleons in a nucleus. In contrast to most non-relativistic operators, these pion-exchange currents can be coherently enhanced by the total number of nucleons, and therefore may dominate in scenarios where spin-independent WIMP-nucleon interactions are suppressed. Moreover, for natural values of the couplings, they dominate over the spin-dependent channel due to their coherence in the nucleus. Using the signal model of this new WIMP-pion channel, no significant excess is found, leading to an upper limit cross section of $6.4\times10^{-46}$ cm$^2$ (90 % confidence level) at 30 GeV/c$^2$ WIMP mass.
hep-ph/0010237
Jon Rosner
Michael Gronau and Jonathan L. Rosner
U-Spin Symmetry in Doubly Cabibbo-Suppressed Charmed Meson Decays
Two references updated, to appear in Phys. Lett. B
Phys.Lett.B500:247-253,2001
10.1016/S0370-2693(01)00080-6
null
hep-ph
null
We prove a U-spin amplitude triangle relation among doubly Cabibbo-suppressed (DCS) charmed meson decays, $D^0\to K^+\pi^-, D^0 \to K^0\pi^0$ and $D^+_s \to K^0 K^+$, congruent to an isospin relation among corresponding Cabibbo-favored (CF) decays. U-spin breaking in relative phases between CF and DCS amplitudes affects time-dependent studies of $D^0-\od$ mixing. Comparison of final state phase patterns in DCS and CF amplitude triangles, which can shed some light on these phases, is carried out in a phenomenological framework incorporating resonance contributions.
[ { "created": "Fri, 20 Oct 2000 15:16:51 GMT", "version": "v1" }, { "created": "Sun, 22 Oct 2000 09:30:17 GMT", "version": "v2" }, { "created": "Thu, 2 Nov 2000 16:14:16 GMT", "version": "v3" }, { "created": "Wed, 10 Jan 2001 12:54:44 GMT", "version": "v4" } ]
2014-11-17
[ [ "Gronau", "Michael", "" ], [ "Rosner", "Jonathan L.", "" ] ]
We prove a U-spin amplitude triangle relation among doubly Cabibbo-suppressed (DCS) charmed meson decays, $D^0\to K^+\pi^-, D^0 \to K^0\pi^0$ and $D^+_s \to K^0 K^+$, congruent to an isospin relation among corresponding Cabibbo-favored (CF) decays. U-spin breaking in relative phases between CF and DCS amplitudes affects time-dependent studies of $D^0-\od$ mixing. Comparison of final state phase patterns in DCS and CF amplitude triangles, which can shed some light on these phases, is carried out in a phenomenological framework incorporating resonance contributions.
1905.02148
Johannes Bl\"umlein
Johannes Bl\"umlein
Large scale analytic calculations in quantum field theories
25 pages Latex, 1 style file
null
null
DESY 18-216, DO-TH 18/28
hep-ph hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a survey on the mathematical structure of zero- and single scale quantities and the associated calculation methods and function spaces in higher order perturbative calculations in relativistic renormalizable quantum field theories.
[ { "created": "Mon, 6 May 2019 17:02:07 GMT", "version": "v1" } ]
2019-05-07
[ [ "Blümlein", "Johannes", "" ] ]
We present a survey on the mathematical structure of zero- and single scale quantities and the associated calculation methods and function spaces in higher order perturbative calculations in relativistic renormalizable quantum field theories.
hep-ph/0105125
A. Perez-Lorenzana
Rouzbeh Allahverdi, Anupam Mazumdar and A. P\'erez-Lorenzana
Final reheating temperature on a single brane
11 pages, no figures. Major changes. Bounds on brane tension removed
Phys.Lett.B516:431-438,2001
10.1016/S0370-2693(01)00967-4
TUM-HEP-416/01
hep-ph astro-ph gr-qc hep-th
null
We make a generic remark on thermal history of a single brane cosmology in models with an infinitely large single extra dimension. We point out that the reheat temperature of the Universe is bounded by an excess production of gravitons from the thermal bath. The actual bound is given by the brane tension. If the initial temperature of the Universe is larger than this bound, then an efficient graviton production shall prevail. However, the brane cools down gradually as the Kaluza-Klein gravitons take the energy in excess away from the brane. The cooling continues until the radiation dominated phase is restored, which occurs before the Big Bang Nucleosynthesis. We argue whatsoever be the early evolution of the Universe, the final radiation dominated phase always starts after the Universe transits from non-conventional era to the standard cosmological era.
[ { "created": "Mon, 14 May 2001 16:05:37 GMT", "version": "v1" }, { "created": "Fri, 13 Jul 2001 16:16:21 GMT", "version": "v2" } ]
2008-11-26
[ [ "Allahverdi", "Rouzbeh", "" ], [ "Mazumdar", "Anupam", "" ], [ "Pérez-Lorenzana", "A.", "" ] ]
We make a generic remark on thermal history of a single brane cosmology in models with an infinitely large single extra dimension. We point out that the reheat temperature of the Universe is bounded by an excess production of gravitons from the thermal bath. The actual bound is given by the brane tension. If the initial temperature of the Universe is larger than this bound, then an efficient graviton production shall prevail. However, the brane cools down gradually as the Kaluza-Klein gravitons take the energy in excess away from the brane. The cooling continues until the radiation dominated phase is restored, which occurs before the Big Bang Nucleosynthesis. We argue whatsoever be the early evolution of the Universe, the final radiation dominated phase always starts after the Universe transits from non-conventional era to the standard cosmological era.
hep-ph/0407112
Walter Grimus
W. Grimus, A.S. Joshipura, S. Kaneko, L. Lavoura, M. Tanimoto
Lepton mixing angle $\theta_{13} = 0$ with a horizontal symmetry $D_4$
13 pages, one figure
JHEP 0407 (2004) 078
10.1088/1126-6708/2004/07/078
UWThPh-2004-14
hep-ph
null
We discuss a model for the lepton sector based on the seesaw mechanism and on a $D_4$ family symmetry. The model predicts the mixing angle $\theta_{13}$ to vanish. The solar mixing angle $\theta_{12}$ is free--it will in general be large if one does not invoke finetuning. The model has an enlarged scalar sector with three Higgs doublets, together with two real scalar gauge singlets $\chi_i$ ($ i = 1, 2$) which have vacuum expectation values < \chi_i >_0$ at the seesaw scale. The atmospheric mixing angle $\theta_{23}$ is given by $\tan \theta_{23} = <\chi_2>_0$ /<\chi_1>_0$, and it is maximal if the Lagrangian is $D_4$-invariant; but $D_4$ may be broken softly, by a term of dimension two in the scalar potential, and then < \chi_2_0$ becomes different from < \chi_1_0$. Thus, the strength of the soft $D_4$ breaking controls the deviation of $\theta_{23}$ from $\pi / 4$. The model predicts a normal neutrino mass spectrum ($m_3 > m_2 > m_1$) and allows successful leptogenesis if $m_1 \sim 4 \times 10^{-3} \mathrm{eV}$; these properties of the model are independent of the presence and strength of the soft $D_4$ breaking.
[ { "created": "Fri, 9 Jul 2004 12:07:17 GMT", "version": "v1" } ]
2009-11-10
[ [ "Grimus", "W.", "" ], [ "Joshipura", "A. S.", "" ], [ "Kaneko", "S.", "" ], [ "Lavoura", "L.", "" ], [ "Tanimoto", "M.", "" ] ]
We discuss a model for the lepton sector based on the seesaw mechanism and on a $D_4$ family symmetry. The model predicts the mixing angle $\theta_{13}$ to vanish. The solar mixing angle $\theta_{12}$ is free--it will in general be large if one does not invoke finetuning. The model has an enlarged scalar sector with three Higgs doublets, together with two real scalar gauge singlets $\chi_i$ ($ i = 1, 2$) which have vacuum expectation values < \chi_i >_0$ at the seesaw scale. The atmospheric mixing angle $\theta_{23}$ is given by $\tan \theta_{23} = <\chi_2>_0$ /<\chi_1>_0$, and it is maximal if the Lagrangian is $D_4$-invariant; but $D_4$ may be broken softly, by a term of dimension two in the scalar potential, and then < \chi_2_0$ becomes different from < \chi_1_0$. Thus, the strength of the soft $D_4$ breaking controls the deviation of $\theta_{23}$ from $\pi / 4$. The model predicts a normal neutrino mass spectrum ($m_3 > m_2 > m_1$) and allows successful leptogenesis if $m_1 \sim 4 \times 10^{-3} \mathrm{eV}$; these properties of the model are independent of the presence and strength of the soft $D_4$ breaking.
hep-ph/0504128
Antoni Szczurek
Tomasz Pietrycki and Antoni Szczurek
Resolved photon and multi-component model for $\gamma^*$p and $\gamma^* \gamma^*$ scattering at high energies
23 pages, 10 figures
Eur.Phys.J.C44:103-110,2005
10.1140/epjc/s2005-02351-5
null
hep-ph
null
We generalize our previous model for $\gamma^* p$ scattering to $\gamma \gamma$ scattering. In the latter case the number of components naturally grows. When using the model parameters from our previous $\gamma^* p$ analysis the model cross section for $\gamma \gamma$ scattering is larger than the corresponding LEP2 experimental data by more than a factor of two. However, performing a new simultaneous fit to $\gamma^* p$ and $\gamma \gamma$ total cross section we can find an optimal set of parameters to describe both processes. We propose new measures of factorization breaking for $\gamma^* \gamma^*$ collisions and present results for our new model.
[ { "created": "Fri, 15 Apr 2005 14:46:46 GMT", "version": "v1" } ]
2009-01-07
[ [ "Pietrycki", "Tomasz", "" ], [ "Szczurek", "Antoni", "" ] ]
We generalize our previous model for $\gamma^* p$ scattering to $\gamma \gamma$ scattering. In the latter case the number of components naturally grows. When using the model parameters from our previous $\gamma^* p$ analysis the model cross section for $\gamma \gamma$ scattering is larger than the corresponding LEP2 experimental data by more than a factor of two. However, performing a new simultaneous fit to $\gamma^* p$ and $\gamma \gamma$ total cross section we can find an optimal set of parameters to describe both processes. We propose new measures of factorization breaking for $\gamma^* \gamma^*$ collisions and present results for our new model.
hep-ph/0307261
Stephane Peigne
Stephane Peigne
Universality-breaking effects in DIS and Drell-Yan
6 pages, 1 figure, talk given at DIS 2003, St. Petersburg, 23-27 April 2003
null
null
LAPTH-Conf-991/03
hep-ph
null
Several properties of high energy hadronic collisions are illustrated by comparing DIS and the Drell-Yan process within a scalar QED model. Diffraction and transverse momentum broadening within the target system are found to be non-universal. Here these effects are simply due to the Coulomb phase shift in the Drell-Yan production amplitude.
[ { "created": "Mon, 21 Jul 2003 13:11:53 GMT", "version": "v1" } ]
2007-05-23
[ [ "Peigne", "Stephane", "" ] ]
Several properties of high energy hadronic collisions are illustrated by comparing DIS and the Drell-Yan process within a scalar QED model. Diffraction and transverse momentum broadening within the target system are found to be non-universal. Here these effects are simply due to the Coulomb phase shift in the Drell-Yan production amplitude.
0711.2046
Kaushik Bhattacharya
Alberto Bravo Garcia, Kaushik Bhattacharya, Sarira Sahu
Neutrino self-energy in a magnetized charge-symmetric medium
6 pages, 1 figure. To appear in the conference proceedings of the XI Mexican workshop on particles and fields 2007
AIPConf.Proc.1026:121-126,2008
10.1063/1.2965033
null
hep-ph
null
In this talk we present the calculation of the neutrino self-energy in presence of a magnetized medium. The magnetized medium consists of electrons, positrons, neutrinos and a uniform classical magnetic field. The background magnetic field is assumed to be weak compared to the $W$-Boson mass as a consequence of which only linear order corrections in the field are included in the $W$ boson propagator. The electron propagator consists all order corrections in the background field. Our calculation is specifically suited for situations where the background plasma may be CP symmetric.
[ { "created": "Tue, 13 Nov 2007 18:43:10 GMT", "version": "v1" }, { "created": "Fri, 21 Dec 2007 20:07:37 GMT", "version": "v2" } ]
2008-11-26
[ [ "Garcia", "Alberto Bravo", "" ], [ "Bhattacharya", "Kaushik", "" ], [ "Sahu", "Sarira", "" ] ]
In this talk we present the calculation of the neutrino self-energy in presence of a magnetized medium. The magnetized medium consists of electrons, positrons, neutrinos and a uniform classical magnetic field. The background magnetic field is assumed to be weak compared to the $W$-Boson mass as a consequence of which only linear order corrections in the field are included in the $W$ boson propagator. The electron propagator consists all order corrections in the background field. Our calculation is specifically suited for situations where the background plasma may be CP symmetric.
1308.2186
Mauricio Martinez
N\'estor Armesto, Hao Ma, Mauricio Martinez, Yacine Mehtar-Tani, Carlos A. Salgado
Coherence phenomena between initial and final state radiation in a dense QCD medium
33 pages, 2 figures. Fix typos and updated references. Discussion in the introduction updated. Accepted for publication in JHEP
JHEP 1312:052, 2013
10.1007/JHEP12(2013)052
CERN-PH-TH/2013-171
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we investigate medium modifications to the interference pattern between initial and final state radiation. We compute single gluon production off a highly energetic parton that undergoes a hard scattering and subsequently crosses a dense QCD medium of finite size. We extend our previous studies obtained at first order in opacity by providing general results for multiple soft scatterings and their specific formulation within the harmonic oscillator approximation. We show that there is a gradual onset of decoherence between the initial and final state radiation due to multiple scatterings, that opens the phase space for large angle emissions. By examining the multiplicity of produced gluons, we observe a potentially large double logarithmic enhancement for dense media and small opening angles. This result points to a possible modification of the evolution equations due to a QCD medium of finite size. We briefly comment on the phenomenological consequences of this setup in high-energy nuclear collisions.
[ { "created": "Fri, 9 Aug 2013 17:02:16 GMT", "version": "v1" }, { "created": "Fri, 22 Nov 2013 20:12:54 GMT", "version": "v2" } ]
2013-12-17
[ [ "Armesto", "Néstor", "" ], [ "Ma", "Hao", "" ], [ "Martinez", "Mauricio", "" ], [ "Mehtar-Tani", "Yacine", "" ], [ "Salgado", "Carlos A.", "" ] ]
In this work we investigate medium modifications to the interference pattern between initial and final state radiation. We compute single gluon production off a highly energetic parton that undergoes a hard scattering and subsequently crosses a dense QCD medium of finite size. We extend our previous studies obtained at first order in opacity by providing general results for multiple soft scatterings and their specific formulation within the harmonic oscillator approximation. We show that there is a gradual onset of decoherence between the initial and final state radiation due to multiple scatterings, that opens the phase space for large angle emissions. By examining the multiplicity of produced gluons, we observe a potentially large double logarithmic enhancement for dense media and small opening angles. This result points to a possible modification of the evolution equations due to a QCD medium of finite size. We briefly comment on the phenomenological consequences of this setup in high-energy nuclear collisions.
0810.2082
Igor Lokhtin P.
I.P.Lokhtin, L.V.Malinina, S.V.Petrushanko, A.M.Snigirev, I.Arsene, K.Tywoniuk
Recent developments on HYDJET/PYQUEN event generators and novel jet quenching observables at LHC
Talk given at International Workshop "High-pT physics at LHC" (Tokaj, Hungary, March 16-19, 2008); 8 pages; prepared using LaTeX package for publication in Proceedings of Science (PoS)
PoS HIGH-pTLHC08:002,2008
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent developments on PYQUEN, HYDJET and HYDJET++ event generators are presented. The partonic energy loss model PYQUEN is implemented as the modification of the "standard" jet event obtained with the generator of hadron-hadron interactions PYTHIA. HYDJET and HYDJET++ are the Monte-Carlo event generators for the simulation of relativistic heavy ion AA collisions considered as a superposition of the soft, hydro-type state and the hard, multi-parton fragmentation. HYDJET++ model is the development and continuation of HYDJET generator, and it includes more detailed treatment of the "thermal" hadronic state generated on the chemical and thermal freeze-out hypersurfaces (represented by the parameterization of relativistic hydrodynamics with preset freeze-out conditions), collective flow effects and decays of hadronic resonances. Some applications of above models to novel jet quenching observables are discussed.
[ { "created": "Sun, 12 Oct 2008 10:38:31 GMT", "version": "v1" } ]
2010-02-09
[ [ "Lokhtin", "I. P.", "" ], [ "Malinina", "L. V.", "" ], [ "Petrushanko", "S. V.", "" ], [ "Snigirev", "A. M.", "" ], [ "Arsene", "I.", "" ], [ "Tywoniuk", "K.", "" ] ]
The recent developments on PYQUEN, HYDJET and HYDJET++ event generators are presented. The partonic energy loss model PYQUEN is implemented as the modification of the "standard" jet event obtained with the generator of hadron-hadron interactions PYTHIA. HYDJET and HYDJET++ are the Monte-Carlo event generators for the simulation of relativistic heavy ion AA collisions considered as a superposition of the soft, hydro-type state and the hard, multi-parton fragmentation. HYDJET++ model is the development and continuation of HYDJET generator, and it includes more detailed treatment of the "thermal" hadronic state generated on the chemical and thermal freeze-out hypersurfaces (represented by the parameterization of relativistic hydrodynamics with preset freeze-out conditions), collective flow effects and decays of hadronic resonances. Some applications of above models to novel jet quenching observables are discussed.
0906.1476
Cristina Volpe
Cristina Volpe
Low energy neutrino scattering : from fundamental interaction studies to astrophysics
6 pages, Proceedings to the 45th Winter School in Theoretical Physics "Neutrino Interactions: from Theory to Monte Carlo Simulations", Ladek-Zdroj, Poland, February 2--11, 2009
Acta Phys.Polon.B40:2545-2550,2009
null
null
hep-ph astro-ph.SR hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutrino scattering at low energies is essential for a variety of timely applications potentially having fundamental implications, e.g. unraveling unknown neutrino properties, such as the third neutrino mixing angle, the detection of the diffuse supernova neutrino background, or of cosmological neutrinos and furnishing a new constraint to double-beta decay calculations. Here we discuss some applications, the present status and the perspectives.
[ { "created": "Mon, 8 Jun 2009 12:19:16 GMT", "version": "v1" } ]
2010-01-15
[ [ "Volpe", "Cristina", "" ] ]
Neutrino scattering at low energies is essential for a variety of timely applications potentially having fundamental implications, e.g. unraveling unknown neutrino properties, such as the third neutrino mixing angle, the detection of the diffuse supernova neutrino background, or of cosmological neutrinos and furnishing a new constraint to double-beta decay calculations. Here we discuss some applications, the present status and the perspectives.
hep-ph/0010152
Yee J. Ng
Y. Jack Ng (University of North Carolina), D.-S. Lee (National Dong Hwa University), M.C. Oh (UNC), and H. van Dam (UNC)
Energy-momentum uncertainties as possible origin of threshold anomalies in UHECR and TeV-gamma ray events
minor changes in text and references
Phys.Lett. B507 (2001) 236-240
10.1016/S0370-2693(01)00436-1
null
hep-ph astro-ph gr-qc hep-th
null
A threshold anomaly refers to a theoretically expected energy threshold that is not observed experimentally. Here we offer an explanation of the threshold anomalies encountered in the ultra-high energy cosmic ray events and the TeV-gamma ray events, by arguing that energy-momentum uncertainties due to quantum gravity, too small to be detected in low-energy regime, can affect particle kinematics so as to raise or even eliminate the energy thresholds. A possible modification of the energy-momentum dispersion relation, giving rise to time-of-flight differences between photons of different energies from gamma ray bursts, is also discussed.
[ { "created": "Sun, 15 Oct 2000 19:34:33 GMT", "version": "v1" }, { "created": "Tue, 24 Oct 2000 16:33:01 GMT", "version": "v2" } ]
2009-10-31
[ [ "Ng", "Y. Jack", "", "University of North Carolina" ], [ "Lee", "D. -S.", "", "National Dong\n Hwa University" ], [ "Oh", "M. C.", "", "UNC" ], [ "van Dam", "H.", "", "UNC" ] ]
A threshold anomaly refers to a theoretically expected energy threshold that is not observed experimentally. Here we offer an explanation of the threshold anomalies encountered in the ultra-high energy cosmic ray events and the TeV-gamma ray events, by arguing that energy-momentum uncertainties due to quantum gravity, too small to be detected in low-energy regime, can affect particle kinematics so as to raise or even eliminate the energy thresholds. A possible modification of the energy-momentum dispersion relation, giving rise to time-of-flight differences between photons of different energies from gamma ray bursts, is also discussed.
hep-ph/0007194
Jon Rosner
Jonathan L. Rosner
Theoretical Issues in the Tevatron Era
18 pages, LaTeX, no figures, invited talk presented at Symposium in Celebration of the Fixed-Target Program with the Tevatron, Fermilab, June 2, 2000, to be published in Comments on Modern Physics. References updated
Comments Nucl.Part.Phys.A2:328-345,2002
null
EFI 2000-24
hep-ph
null
The Fermilab Tevatron's operation for fixed-target physics from its start in 1983 until the end of fixed-target running in 2000 was marked by extraordinary peoductivity and variety. Some of the changing theoretal issues associated with this program are reviewed.
[ { "created": "Tue, 18 Jul 2000 19:28:23 GMT", "version": "v1" }, { "created": "Thu, 10 Aug 2000 19:44:54 GMT", "version": "v2" }, { "created": "Thu, 20 Jun 2002 15:32:00 GMT", "version": "v3" } ]
2014-11-17
[ [ "Rosner", "Jonathan L.", "" ] ]
The Fermilab Tevatron's operation for fixed-target physics from its start in 1983 until the end of fixed-target running in 2000 was marked by extraordinary peoductivity and variety. Some of the changing theoretal issues associated with this program are reviewed.
hep-ph/0506216
Yuval Grossman
Yuval Grossman, Can Kilic, Jesse Thaler, Devin G. E. Walker
Neutrino Constraints on Spontaneous Lorentz Violation
27 pages, 1 figure
Phys.Rev. D72 (2005) 125001
10.1103/PhysRevD.72.125001
null
hep-ph
null
We study the effect of spontaneous Lorentz violation on neutrinos. We consider two kinds of effects: static effects, where the neutrino acquires a Lorentz-violating dispersion relation, and dynamic effects, which arise from the interactions of the neutrino with the Goldstone boson of spontaneous Lorentz violation. Static effects are well detailed in the literature. Here, special emphasis is given to the novel dynamic effect of Goldstone-Cerenkov radiation, where neutrinos moving with respect to a preferred rest frame can spontaneously emit Goldstone bosons. We calculate the observable consequences of this process and use them to derive experimental bounds from SN1987A and the CMBR. The bounds derived from dynamic effects are complementary to - and in many cases much stronger than - those obtained from static effects.
[ { "created": "Wed, 22 Jun 2005 18:20:38 GMT", "version": "v1" } ]
2013-05-29
[ [ "Grossman", "Yuval", "" ], [ "Kilic", "Can", "" ], [ "Thaler", "Jesse", "" ], [ "Walker", "Devin G. E.", "" ] ]
We study the effect of spontaneous Lorentz violation on neutrinos. We consider two kinds of effects: static effects, where the neutrino acquires a Lorentz-violating dispersion relation, and dynamic effects, which arise from the interactions of the neutrino with the Goldstone boson of spontaneous Lorentz violation. Static effects are well detailed in the literature. Here, special emphasis is given to the novel dynamic effect of Goldstone-Cerenkov radiation, where neutrinos moving with respect to a preferred rest frame can spontaneously emit Goldstone bosons. We calculate the observable consequences of this process and use them to derive experimental bounds from SN1987A and the CMBR. The bounds derived from dynamic effects are complementary to - and in many cases much stronger than - those obtained from static effects.
hep-ph/0508059
Bo Feng
Chi-Yi Chen, You-Gen Shen and Bo Feng
Spontaneous Leptogenesis in Brans-Dicke Cosmology
9 pages Revetex4. First submission on Thu, 25 Nov 2004, HP&NP in press
HighEnergyPhys.Nucl.Phys.29:1033-1040,2005
null
null
hep-ph astro-ph gr-qc hep-th
null
The role of the auxiliary scalar field $\phi$ of Brans-Dicke theory played in baryon number asymmetry is discussed in this paper. We consider a derivative coupling of this gravitational scalar field to the baryon current ${J^{\mu}}_B$ or the current of the baryon number minus lepton number ${J^{\mu}}_{B-L}$ based on a series of works of R. Morganstern about the Brans-Dicke cosmology. We find that the spontaneous baryogenesis by this coupling is capable to yield a sufficient baryon asymmetry $n_B/s\sim 10^{10} $ for the time of the grand unification is in a little advanced. In addition, Davoudiasl et al have recently introduced a new type of interaction between the Ricci scalar $R$ and the bayon current $J^{\mu}$, $\partial_{\mu}R J^{\mu}$ and also proposed a mechanism for baryogenesis, the gravitational baryogenesis. However, the Einstein equation tell us that $\dot{R}=0$ in the radiation-dominated epoch of the standard FRW cosmology. In this paper we reconsider the feasibility of having gravitational baryongenesis with such a form of interaction in radiation-filled Brans-Dicke cosmology. We will show that $\dot{R}$ does not vanish in this case and the required baryon number asymmetry can also be achieved.
[ { "created": "Thu, 4 Aug 2005 17:44:02 GMT", "version": "v1" } ]
2016-09-06
[ [ "Chen", "Chi-Yi", "" ], [ "Shen", "You-Gen", "" ], [ "Feng", "Bo", "" ] ]
The role of the auxiliary scalar field $\phi$ of Brans-Dicke theory played in baryon number asymmetry is discussed in this paper. We consider a derivative coupling of this gravitational scalar field to the baryon current ${J^{\mu}}_B$ or the current of the baryon number minus lepton number ${J^{\mu}}_{B-L}$ based on a series of works of R. Morganstern about the Brans-Dicke cosmology. We find that the spontaneous baryogenesis by this coupling is capable to yield a sufficient baryon asymmetry $n_B/s\sim 10^{10} $ for the time of the grand unification is in a little advanced. In addition, Davoudiasl et al have recently introduced a new type of interaction between the Ricci scalar $R$ and the bayon current $J^{\mu}$, $\partial_{\mu}R J^{\mu}$ and also proposed a mechanism for baryogenesis, the gravitational baryogenesis. However, the Einstein equation tell us that $\dot{R}=0$ in the radiation-dominated epoch of the standard FRW cosmology. In this paper we reconsider the feasibility of having gravitational baryongenesis with such a form of interaction in radiation-filled Brans-Dicke cosmology. We will show that $\dot{R}$ does not vanish in this case and the required baryon number asymmetry can also be achieved.
2401.11211
Yong Zhang
Yong Zhang and Peng Ru
Squeezed correlations of bosons with nonzero widths for expanding sources
8 pages, 6 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We explore the squeezed back-to-back correlation (SBBC) and investigate how the squeezing effect influences the Hanbury Brown-Twiss (HBT) interferometry using an expanding Gaussian source with non-zero width. The SBBC and HBT of $D^0$ and $\phi$ mesons with finite in-medium widths are studied. The expanding flow of the source may enhance the SBBC strength of $D^0{\bar D}^0$ and $\phi\phi$ in the low momentum region but suppress the SBBC in the larger momentum region. The squeezing effect suppresses the influence of flow on the HBT radii, which is significant for two identical bosons with large pair momentum or with large mass. Due to the squeezing effect, the relationship between the HBT radii and the pair momentum exhibits non-flow behavior for $D^0D^0$ pair. Likewise, non-flow behavior also appears in the HBT radii of $\phi\phi$ with large pair momentum. This phenomenon may bring new insights for studying the squeezing effect.
[ { "created": "Sat, 20 Jan 2024 11:28:09 GMT", "version": "v1" } ]
2024-01-23
[ [ "Zhang", "Yong", "" ], [ "Ru", "Peng", "" ] ]
We explore the squeezed back-to-back correlation (SBBC) and investigate how the squeezing effect influences the Hanbury Brown-Twiss (HBT) interferometry using an expanding Gaussian source with non-zero width. The SBBC and HBT of $D^0$ and $\phi$ mesons with finite in-medium widths are studied. The expanding flow of the source may enhance the SBBC strength of $D^0{\bar D}^0$ and $\phi\phi$ in the low momentum region but suppress the SBBC in the larger momentum region. The squeezing effect suppresses the influence of flow on the HBT radii, which is significant for two identical bosons with large pair momentum or with large mass. Due to the squeezing effect, the relationship between the HBT radii and the pair momentum exhibits non-flow behavior for $D^0D^0$ pair. Likewise, non-flow behavior also appears in the HBT radii of $\phi\phi$ with large pair momentum. This phenomenon may bring new insights for studying the squeezing effect.
2306.03524
Subhadeep Roy
Subhadeep Roy, Tulika Tripathy, Sadhana Dash
Multiplicity and Transverse Spherocity dependence of $\langle p_{\rm T} \rangle$ fluctuations of charged particles in p$-$p collisions at $\sqrt{s}$ = 7 and 13 TeV
8 pages, 16 figures
null
null
null
hep-ph nucl-ex
http://creativecommons.org/licenses/by/4.0/
The multiplicity dependence of event-by-event fluctuations in mean transverse momentum, $\langle p_{\rm T} \rangle$, of charged particles has been studied in p$-$p collisions at $\sqrt{s}$ = 7 TeV and 13 TeV using the PYTHIA 8 event generator. The charged particles were selected in kinematic range of $0.15 < p_{\rm T}<2$ GeV$/c$ and $|\eta| < 0.8$. The dynamical fluctuations would indicate towards the correlated emission of particles. The measurements in A$-$A and p$-$p collisions has shown a decrease in the strength of $ \langle p_{\rm T} \rangle$ fluctuations with the average charged particle multiplicity. The effects of various microscopic processes like color reconnection and multi-partonic interactions has been studied. A minimal dependency on the collision energy is also observed. Furthermore, the fluctuation observables are investigated in the intervals of transverse spherocity in order to comprehend the relative contributions resulting from hard scattering and underlying events. The present study would act as a baseline for future measurements in A$-$A as well as p$-$p collisions at the LHC.
[ { "created": "Tue, 6 Jun 2023 09:18:44 GMT", "version": "v1" } ]
2023-06-07
[ [ "Roy", "Subhadeep", "" ], [ "Tripathy", "Tulika", "" ], [ "Dash", "Sadhana", "" ] ]
The multiplicity dependence of event-by-event fluctuations in mean transverse momentum, $\langle p_{\rm T} \rangle$, of charged particles has been studied in p$-$p collisions at $\sqrt{s}$ = 7 TeV and 13 TeV using the PYTHIA 8 event generator. The charged particles were selected in kinematic range of $0.15 < p_{\rm T}<2$ GeV$/c$ and $|\eta| < 0.8$. The dynamical fluctuations would indicate towards the correlated emission of particles. The measurements in A$-$A and p$-$p collisions has shown a decrease in the strength of $ \langle p_{\rm T} \rangle$ fluctuations with the average charged particle multiplicity. The effects of various microscopic processes like color reconnection and multi-partonic interactions has been studied. A minimal dependency on the collision energy is also observed. Furthermore, the fluctuation observables are investigated in the intervals of transverse spherocity in order to comprehend the relative contributions resulting from hard scattering and underlying events. The present study would act as a baseline for future measurements in A$-$A as well as p$-$p collisions at the LHC.
1401.8291
Benedict v. Harling
Tony Gherghetta, Benedict von Harling, Anibal D. Medina, Michael A. Schmidt
The price of being SM-like in SUSY
29 pages, 6 figures
null
10.1007/JHEP04(2014)180
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the tuning in supersymmetric models associated with the constraints from collider measurements of the Higgs couplings to fermions and gauge bosons. In supersymmetric models, a CP-even state with SM Higgs couplings mixes with additional, heavier CP-even states, causing deviations in the Higgs couplings from SM values. These deviations are reduced as the heavy states are decoupled with large soft masses, thereby exacerbating the tuning associated with the electroweak scale. This new source of tuning is different from that derived from collider limits on stops, gluinos and Higgsinos. It can be offset with large tan beta in the MSSM, however this compensating effect is limited in the NMSSM with a large Higgs-singlet coupling due to restrictions on large tan beta from electroweak precision tests. We derive a lower bound on this tuning and show that the level of precision of Higgs coupling measurements at the LHC will probe naturalness in the NMSSM at the few-percent level. This is comparable to the tuning derived from superpartner limits in models with a low messenger scale and split families. Instead the significant improvement in sensitivity of Higgs coupling measurements at the ILC will allow naturalness in these models to be constrained at the per-mille level, beyond any tuning derived from direct superpartner limits.
[ { "created": "Fri, 31 Jan 2014 20:47:08 GMT", "version": "v1" } ]
2015-06-18
[ [ "Gherghetta", "Tony", "" ], [ "von Harling", "Benedict", "" ], [ "Medina", "Anibal D.", "" ], [ "Schmidt", "Michael A.", "" ] ]
We compute the tuning in supersymmetric models associated with the constraints from collider measurements of the Higgs couplings to fermions and gauge bosons. In supersymmetric models, a CP-even state with SM Higgs couplings mixes with additional, heavier CP-even states, causing deviations in the Higgs couplings from SM values. These deviations are reduced as the heavy states are decoupled with large soft masses, thereby exacerbating the tuning associated with the electroweak scale. This new source of tuning is different from that derived from collider limits on stops, gluinos and Higgsinos. It can be offset with large tan beta in the MSSM, however this compensating effect is limited in the NMSSM with a large Higgs-singlet coupling due to restrictions on large tan beta from electroweak precision tests. We derive a lower bound on this tuning and show that the level of precision of Higgs coupling measurements at the LHC will probe naturalness in the NMSSM at the few-percent level. This is comparable to the tuning derived from superpartner limits in models with a low messenger scale and split families. Instead the significant improvement in sensitivity of Higgs coupling measurements at the ILC will allow naturalness in these models to be constrained at the per-mille level, beyond any tuning derived from direct superpartner limits.
2310.18810
Gustavo Xavier Antunes Petronilo Msc.
M. Abu-Shady, R. R. Luz, G. X. A. Petronilo, A. E. Santana, R. G. G. Amorim
On the Fractional Quark-Antiquark Confinement and Symplectic Quantum Mechanics
11 pages, 3 figures
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using the formalism of generalized fractional derivatives, a two-dimensional non-relativistic meson system is studied. The mesons are interacting by a Cornell potential. The system is formulated in the domain of the symplectic quantum mechanics by means of the generalized fractional Nikiforov-Uvarov method. The corresponding Wigner function and the energy eigenvalues are then derived. The effect of fractional parameters $\alpha$ and $\beta$ with the ground state solution is analyzed through the Wigner function for the charm-anticharm, bottom-antibottom and $b\overline{c}$ mesons. One of the fundamental achievements of such Cornell model is the determination of heavy quarkonia mass spectra. We have computed these masses and the
[ { "created": "Sat, 28 Oct 2023 20:29:02 GMT", "version": "v1" }, { "created": "Mon, 13 Nov 2023 19:41:50 GMT", "version": "v2" }, { "created": "Mon, 15 Jan 2024 14:08:37 GMT", "version": "v3" } ]
2024-01-17
[ [ "Abu-Shady", "M.", "" ], [ "Luz", "R. R.", "" ], [ "Petronilo", "G. X. A.", "" ], [ "Santana", "A. E.", "" ], [ "Amorim", "R. G. G.", "" ] ]
Using the formalism of generalized fractional derivatives, a two-dimensional non-relativistic meson system is studied. The mesons are interacting by a Cornell potential. The system is formulated in the domain of the symplectic quantum mechanics by means of the generalized fractional Nikiforov-Uvarov method. The corresponding Wigner function and the energy eigenvalues are then derived. The effect of fractional parameters $\alpha$ and $\beta$ with the ground state solution is analyzed through the Wigner function for the charm-anticharm, bottom-antibottom and $b\overline{c}$ mesons. One of the fundamental achievements of such Cornell model is the determination of heavy quarkonia mass spectra. We have computed these masses and the
hep-ph/9810245
null
A. Barducci, R. Casalbuoni, R. Gatto, M. Modugno, G. Pettini
Pseudoscalar and scalar meson masses at finite temperature
19 pages, Revtex, 2 Postscript figures
Phys.Rev. D59 (1999) 114024
10.1103/PhysRevD.59.114024
UGVA-DPT 1998/09-1015, DFF-320/09/1998
hep-ph hep-th nucl-th
null
The composite operator formalism is applied to QCD at finite temperature to calculate the masses of scalar and pseudoscalar mesons. In particular the ratio of the sigma mass to the pion mass is an interesting measure of the degree of chiral symmetry breaking at different temperatures. We calculate the temperature T* at which M_sigma(T) < 2M_pi(T), above which the sigma partial width into two pions vanishes. We find T*=0.95T_c (where T_c is the critical temperature for the chiral phase transition), within the full effective potential given by the formalism. We find that an expansion a-la Landau of the effective potential around the critical point in the limit of small quark mass provides for a very good determination of T*.
[ { "created": "Mon, 5 Oct 1998 09:39:32 GMT", "version": "v1" } ]
2009-10-31
[ [ "Barducci", "A.", "" ], [ "Casalbuoni", "R.", "" ], [ "Gatto", "R.", "" ], [ "Modugno", "M.", "" ], [ "Pettini", "G.", "" ] ]
The composite operator formalism is applied to QCD at finite temperature to calculate the masses of scalar and pseudoscalar mesons. In particular the ratio of the sigma mass to the pion mass is an interesting measure of the degree of chiral symmetry breaking at different temperatures. We calculate the temperature T* at which M_sigma(T) < 2M_pi(T), above which the sigma partial width into two pions vanishes. We find T*=0.95T_c (where T_c is the critical temperature for the chiral phase transition), within the full effective potential given by the formalism. We find that an expansion a-la Landau of the effective potential around the critical point in the limit of small quark mass provides for a very good determination of T*.
1304.1589
Masashi Wakamatsu
Masashi Wakamatsu
More on the relation between the two physically inequivalent decompositions of the nucleon spin
Invited Talk at the Third Workshop on the QCD Structure of the Nucleon (QCD N'12), Bilbao, Spain, 22-26 October 2012
null
10.1393/ncc/i2013-11604-5
OU-HET-778
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent controversy on the nucleon spin decomposition problem is critically overviewed. We argue that there exist two and only two physically inequivalent gauge-invariant decompositions of the longitudinal nucleon spin, contrary to the rapidly spreading view in the QCD spin physics community that there are infinitely many decompositions of the nucleon spin.
[ { "created": "Fri, 5 Apr 2013 00:38:47 GMT", "version": "v1" } ]
2022-03-02
[ [ "Wakamatsu", "Masashi", "" ] ]
The recent controversy on the nucleon spin decomposition problem is critically overviewed. We argue that there exist two and only two physically inequivalent gauge-invariant decompositions of the longitudinal nucleon spin, contrary to the rapidly spreading view in the QCD spin physics community that there are infinitely many decompositions of the nucleon spin.
hep-ph/0007311
Kirill Tuchin
K. Tuchin (Tel Aviv U.)
The Pomeron intercept in $\lambda\phi^3$ theory in 4 Minkowski + 1 compact dimensions
9 pages, 3 figures
Phys.Lett. B497 (2001) 111-116
10.1016/S0370-2693(00)01321-6
TAUP-2641-2000
hep-ph
null
We calculate the total cross section for two scalar particles scattering at high energies in $\lambda\phi^3$ theory in five dimensions, four of which are usual Minkowski ones and the fifth is compact. It is shown that the cross section is dominated by exchange of Pomeron whose intercept is larger than in usual four-dimensional case.
[ { "created": "Thu, 27 Jul 2000 10:33:42 GMT", "version": "v1" } ]
2009-10-31
[ [ "Tuchin", "K.", "", "Tel Aviv U." ] ]
We calculate the total cross section for two scalar particles scattering at high energies in $\lambda\phi^3$ theory in five dimensions, four of which are usual Minkowski ones and the fifth is compact. It is shown that the cross section is dominated by exchange of Pomeron whose intercept is larger than in usual four-dimensional case.
0903.5175
Gyulnara Eyyubova
L.V. Bravina, G.Kh.Eyyubova, V.L. Korotkikh, I.P. Lokhtin, L.V. Malinina, S.V. Petrushanko, A.M. Snigirev, E.E. Zabrodin
HYDJET++ simulations and reconstruction of the anisotropic flow in Pb+Pb collisions at the LHC
10 pages, Conference: High-pT Physics at LHC -09, February 4- 7 2009, Prague, Czech Republic
PoS High-pTphysics09:047,2009
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The azimuthal anisotropy of charged particles in heavy ion collisions is an important probe of quark-gluon plasma evolution at early stages. In the present paper the elliptic flow pattern in Pb+Pb collisions at sqrt{s}=5.5 TeV is analyzed for different hadron species in the frameworks of HYDJET++ Monte-Carlo model. The influence of resonance decays on particle flow is investigated. The different methods of elliptic flow reconstruction are compared under LHC conditions.
[ { "created": "Mon, 30 Mar 2009 10:33:35 GMT", "version": "v1" } ]
2014-11-18
[ [ "Bravina", "L. V.", "" ], [ "Eyyubova", "G. Kh.", "" ], [ "Korotkikh", "V. L.", "" ], [ "Lokhtin", "I. P.", "" ], [ "Malinina", "L. V.", "" ], [ "Petrushanko", "S. V.", "" ], [ "Snigirev", "A. M.", "" ], [ "Zabrodin", "E. E.", "" ] ]
The azimuthal anisotropy of charged particles in heavy ion collisions is an important probe of quark-gluon plasma evolution at early stages. In the present paper the elliptic flow pattern in Pb+Pb collisions at sqrt{s}=5.5 TeV is analyzed for different hadron species in the frameworks of HYDJET++ Monte-Carlo model. The influence of resonance decays on particle flow is investigated. The different methods of elliptic flow reconstruction are compared under LHC conditions.
2203.05310
Jorge Portoles
Jorge Portoles (IFIC, Valencia)
Physics of the tau lepton
10 pp, 4 Fig. Lecture given at the XIX Mexican School of Particles and Fields (online; 9-13 August 2021)
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within our present knowledge, the tau is the heaviest lepton and the only one decaying into hadrons, a fact that makes it the source of a very rich phenomenology. It represents the third family of leptons in the Standard Model, a feature that helps its classification but whose real meaning is not asserted yet. The tau lepton provides: i) a clean and unique environment to study both the hadronization of QCD currents, in an energy region populated by resonances, and the phenomenological determination of relevant parameters of the Model; ii) together with the muon, they have a very constrained flavour dynamics (in the absence of neutrino masses) due to an accidental global symmetry of the Standard Model. In consequence, the tau lepton brings an excellent benchmark for the study of QCD at low energies and, at the same time, for the search of new physics.
[ { "created": "Thu, 10 Mar 2022 11:51:03 GMT", "version": "v1" } ]
2022-03-11
[ [ "Portoles", "Jorge", "", "IFIC, Valencia" ] ]
Within our present knowledge, the tau is the heaviest lepton and the only one decaying into hadrons, a fact that makes it the source of a very rich phenomenology. It represents the third family of leptons in the Standard Model, a feature that helps its classification but whose real meaning is not asserted yet. The tau lepton provides: i) a clean and unique environment to study both the hadronization of QCD currents, in an energy region populated by resonances, and the phenomenological determination of relevant parameters of the Model; ii) together with the muon, they have a very constrained flavour dynamics (in the absence of neutrino masses) due to an accidental global symmetry of the Standard Model. In consequence, the tau lepton brings an excellent benchmark for the study of QCD at low energies and, at the same time, for the search of new physics.
2202.11753
Elina Fuchs
Henning Bahl, Elina Fuchs, Sven Heinemeyer, Judith Katzy, Marco Menen, Krisztian Peters, Matthias Saimpert, Georg Weiglein
Constraining the CP structure of Higgs-fermion couplings with a global LHC fit, the electron EDM and baryogenesis
40 pages + references, 18 figures
null
10.1140/epjc/s10052-022-10528-1
CERN-TH-2021-231, DESY-22-033, EFI-22-1, IFT--UAM/CSIC--21-148
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
CP violation in the Higgs couplings to fermions is an intriguing, but not yet extensively explored possibility. We use inclusive and differential LHC Higgs boson measurements to fit the CP structure of the Higgs Yukawa couplings. Starting with simple effective models featuring CP violation in a single Higgs-fermion coupling, we probe well-motivated models with up to nine free parameters. We also investigate the complementarity of LHC constraints with the electron electric dipole moment bound, taking into account the possibility of a modified electron Yukawa coupling, and assess to which extent CP violation in the Higgs-fermion couplings can contribute to the observed baryon asymmetry of the universe. Even after including the recent analysis of angular correlations in $H\to\tau^+\tau^-$ decays, we find that a complex tau Yukawa coupling alone may be able to account for the observed baryon asymmetry, but with large uncertainties in the baryogenesis calculation. A combination of complex top and bottom quark Yukawa couplings yields a result four times larger than the sum of their separate contributions, but remains insufficient to account for the observed baryon asymmetry.
[ { "created": "Wed, 23 Feb 2022 19:26:35 GMT", "version": "v1" } ]
2022-07-27
[ [ "Bahl", "Henning", "" ], [ "Fuchs", "Elina", "" ], [ "Heinemeyer", "Sven", "" ], [ "Katzy", "Judith", "" ], [ "Menen", "Marco", "" ], [ "Peters", "Krisztian", "" ], [ "Saimpert", "Matthias", "" ], [ "Weiglein", "Georg", "" ] ]
CP violation in the Higgs couplings to fermions is an intriguing, but not yet extensively explored possibility. We use inclusive and differential LHC Higgs boson measurements to fit the CP structure of the Higgs Yukawa couplings. Starting with simple effective models featuring CP violation in a single Higgs-fermion coupling, we probe well-motivated models with up to nine free parameters. We also investigate the complementarity of LHC constraints with the electron electric dipole moment bound, taking into account the possibility of a modified electron Yukawa coupling, and assess to which extent CP violation in the Higgs-fermion couplings can contribute to the observed baryon asymmetry of the universe. Even after including the recent analysis of angular correlations in $H\to\tau^+\tau^-$ decays, we find that a complex tau Yukawa coupling alone may be able to account for the observed baryon asymmetry, but with large uncertainties in the baryogenesis calculation. A combination of complex top and bottom quark Yukawa couplings yields a result four times larger than the sum of their separate contributions, but remains insufficient to account for the observed baryon asymmetry.
hep-ph/0512183
Simone Pacetti
R. Baldini Ferroli (BaBar Coll.)
BaBar results on e+e- --> ppbar by means of initial state radiation
Talk given at EPS International Europhysics Conference on High Energy Physics (HEPP-EPS 2005), Lisbon, Portugal, 21-27 Jul 2005. 5 pages, 4 figures
PoS HEP2005:285,2006
null
null
hep-ph
null
BaBar has measured with unprecedented accuracy the e+e- --> ppbar cross section from the threshold up to Q^2 ~ 20 GeV^2/c^4, finding out an unexpected cross section, with plateaux and negative steps. Evidence for a ratio |G_E/G_M|>1 has also been found as well as a sudden variation in |G_M| just above the threshold.
[ { "created": "Wed, 14 Dec 2005 15:34:06 GMT", "version": "v1" } ]
2009-08-07
[ [ "Ferroli", "R. Baldini", "", "BaBar Coll." ] ]
BaBar has measured with unprecedented accuracy the e+e- --> ppbar cross section from the threshold up to Q^2 ~ 20 GeV^2/c^4, finding out an unexpected cross section, with plateaux and negative steps. Evidence for a ratio |G_E/G_M|>1 has also been found as well as a sudden variation in |G_M| just above the threshold.
0909.1369
Kuang-Ta Chao
Bai-Qing Li and Kuang-Ta Chao
Bottomonium Spectrum with Screened Potential
9 pages, Commun. Theor. Phys. (in press)
Commun.Theor.Phys.52:653-661,2009
10.1088/0253-6102/52/4/20
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As a sister work of Ref.[1], we incorporate the color-screening effect due to light quark pair creation into the heavy quark-antiquark potential, and investigate the effects of screened potential on the spectrum of bottomonium. We calculate the masses, electromagnetic decays, and E1 transitions of bottomonium states. We find that the fine splittings between $\chi_{bJ}$ (J=0,1,2) states are in good agreement with experimental data, and the E1 transition rates of $\Upsilon(2S)\to\gamma\chi_{bJ}(1P)$ and $\Upsilon(3S)\to\gamma\chi_{bJ}(2P)$ (J=0,1,2) all agree with data within experimental errors. In particular, the mass of $\Upsilon(6S)$ is lowered down to match that of the $\Upsilon(11020)$, which is smaller than the predictions of the linear potential models by more than 100 MeV. Comparison between charmonium and bottomonium in some related problems is also discussed.
[ { "created": "Tue, 8 Sep 2009 01:41:01 GMT", "version": "v1" } ]
2009-11-30
[ [ "Li", "Bai-Qing", "" ], [ "Chao", "Kuang-Ta", "" ] ]
As a sister work of Ref.[1], we incorporate the color-screening effect due to light quark pair creation into the heavy quark-antiquark potential, and investigate the effects of screened potential on the spectrum of bottomonium. We calculate the masses, electromagnetic decays, and E1 transitions of bottomonium states. We find that the fine splittings between $\chi_{bJ}$ (J=0,1,2) states are in good agreement with experimental data, and the E1 transition rates of $\Upsilon(2S)\to\gamma\chi_{bJ}(1P)$ and $\Upsilon(3S)\to\gamma\chi_{bJ}(2P)$ (J=0,1,2) all agree with data within experimental errors. In particular, the mass of $\Upsilon(6S)$ is lowered down to match that of the $\Upsilon(11020)$, which is smaller than the predictions of the linear potential models by more than 100 MeV. Comparison between charmonium and bottomonium in some related problems is also discussed.
hep-ph/9907459
Alessandro Papa
R. Fiore, A. Flachi, L.L. Jenkovszky, F. Paccanoni, A. Papa
Triple Pomeron and Proton Diffraction Dissociation
21 pages, LaTeX, 4 EPS figures, uses epsf.sty
Phys.Rev. D61 (2000) 034004
10.1103/PhysRevD.61.034004
DFPD 99/TH/31, UNICAL-TH 99/2, BITP-99-3E
hep-ph
null
We consider proton diffraction dissociation in the dipole Pomeron model, where the Pomeron is represented by a double pole in the $J-$plane, and show that unitarity can be satisfied without decoupling of the triple Pomeron vertex. Differential and total diffractive cross sections for the reaction $\bar{p}+p \to \bar{p}+X$ are analyzed and reproduced in this model.
[ { "created": "Thu, 22 Jul 1999 15:18:41 GMT", "version": "v1" } ]
2009-10-31
[ [ "Fiore", "R.", "" ], [ "Flachi", "A.", "" ], [ "Jenkovszky", "L. L.", "" ], [ "Paccanoni", "F.", "" ], [ "Papa", "A.", "" ] ]
We consider proton diffraction dissociation in the dipole Pomeron model, where the Pomeron is represented by a double pole in the $J-$plane, and show that unitarity can be satisfied without decoupling of the triple Pomeron vertex. Differential and total diffractive cross sections for the reaction $\bar{p}+p \to \bar{p}+X$ are analyzed and reproduced in this model.
1312.4004
Yao-Bei Liu
Yao-Bei Liu, Zhen-Jun Xiao
Production and decays of a light $\phi^0$ in the LRTH model under the LHC Higgs data
null
JHEP 1402 (2014) 128
10.1007/JHEP02(2014)128
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we study the production and decays of a light pseudoscalar boson $\phi^0$ with $m_{\phi^0} \leq m_h/2$ appeared in the left-right twin Higgs (LRTH) model, and explore its phenomenological consequences when the latest LHC Higgs data are taken into account. We found that (a) the decay rate $Br(h\to \phi^0\phi^0)$ can be as large as $80\%$ and can suppress significantly the visible $\gamma\gamma$ signal rate, but the latest LHC Higgs data put a strong constraint on it: $Br(h \to \phi^0\phi^0) \leq 30\%$ at $3\sigma$ level; (b) the $p$-value of the LRTH model is around $0.6$, smaller than that of the SM in most of the parameter space and approaches the SM value $0.8$ for a sufficiently large $f$ parameter; (c) the neutral pseudoscalar $\phi^0$ dominantly decay into $b\bar{b}$ and the decay rate $Br(\phi^0\to b\bar{b})$ can be larger than $80\%$ for $m_{\phi^0}\leq 60$ GeV, and the second main decay mode is $\phi^0\to \tau^{+}\tau^{-}$ with a branching ratio about $14\%$; and (d) at the future $e^-e^+$ collider with $\sqrt{s}=250$ GeV, the processes $e^{+}e^{-}\to Zh\to Z(\phi^0\phi^0)\to Z(4b,2b2\tau)$ are promising for discovering such a light pseudoscalar $\phi^0$.
[ { "created": "Sat, 14 Dec 2013 05:17:15 GMT", "version": "v1" }, { "created": "Thu, 17 Nov 2016 01:04:51 GMT", "version": "v2" } ]
2016-11-18
[ [ "Liu", "Yao-Bei", "" ], [ "Xiao", "Zhen-Jun", "" ] ]
In this paper we study the production and decays of a light pseudoscalar boson $\phi^0$ with $m_{\phi^0} \leq m_h/2$ appeared in the left-right twin Higgs (LRTH) model, and explore its phenomenological consequences when the latest LHC Higgs data are taken into account. We found that (a) the decay rate $Br(h\to \phi^0\phi^0)$ can be as large as $80\%$ and can suppress significantly the visible $\gamma\gamma$ signal rate, but the latest LHC Higgs data put a strong constraint on it: $Br(h \to \phi^0\phi^0) \leq 30\%$ at $3\sigma$ level; (b) the $p$-value of the LRTH model is around $0.6$, smaller than that of the SM in most of the parameter space and approaches the SM value $0.8$ for a sufficiently large $f$ parameter; (c) the neutral pseudoscalar $\phi^0$ dominantly decay into $b\bar{b}$ and the decay rate $Br(\phi^0\to b\bar{b})$ can be larger than $80\%$ for $m_{\phi^0}\leq 60$ GeV, and the second main decay mode is $\phi^0\to \tau^{+}\tau^{-}$ with a branching ratio about $14\%$; and (d) at the future $e^-e^+$ collider with $\sqrt{s}=250$ GeV, the processes $e^{+}e^{-}\to Zh\to Z(\phi^0\phi^0)\to Z(4b,2b2\tau)$ are promising for discovering such a light pseudoscalar $\phi^0$.
1603.08470
Alexandros Karam
Alexandros Karam, Kyriakos Tamvakis
Dark matter and neutrino masses from a classically scale-invariant multi-Higgs portal
12 pages, 6 figures, Talk ( based on paper http://arxiv.org/abs/1508.03031 ) given at "School and Workshops on Elementary Particle Physics and Gravity", Corfu Summer Institute, September 2015
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a classically scale-invariant model where the dark matter, neutrino and electroweak mass scales are dynamically generated from dimensionless couplings. The Standard Model gauge sector is extended by a dark $SU(2)_X$ gauge symmetry that is completely broken through a complex scalar doublet via the Coleman-Weinberg mechanism. The three resulting dark vector bosons of equal mass are stable and can play the role of dark matter. We also incorporate right-handed neutrinos which are coupled to a real singlet scalar that communicates with the other scalars through portal interactions. The multi-Higgs sector is analyzed by imposing theoretical and experimental constraints. We compute the dark matter relic abundance and study the possibility of the direct detection of the dark matter candidate from XENON 1T.
[ { "created": "Mon, 28 Mar 2016 18:18:56 GMT", "version": "v1" } ]
2016-03-29
[ [ "Karam", "Alexandros", "" ], [ "Tamvakis", "Kyriakos", "" ] ]
We present a classically scale-invariant model where the dark matter, neutrino and electroweak mass scales are dynamically generated from dimensionless couplings. The Standard Model gauge sector is extended by a dark $SU(2)_X$ gauge symmetry that is completely broken through a complex scalar doublet via the Coleman-Weinberg mechanism. The three resulting dark vector bosons of equal mass are stable and can play the role of dark matter. We also incorporate right-handed neutrinos which are coupled to a real singlet scalar that communicates with the other scalars through portal interactions. The multi-Higgs sector is analyzed by imposing theoretical and experimental constraints. We compute the dark matter relic abundance and study the possibility of the direct detection of the dark matter candidate from XENON 1T.
1509.07167
Sebastian Buchta
Sebastian Buchta
Theoretical foundations and applications of the Loop-Tree Duality in Quantum Field Theories
152 pages, Ph.D. thesis
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Loop-Tree Duality (LTD) is a novel perturbative method in QFT that establishes a relation between loop-level and tree-level scattering amplitudes. This is achieved by directly applying the Residue Theorem to the loop-energy-integration. The result is a sum over all possible single cuts of the Feynman diagram in consideration integrated over a modified phase space. These single-cut integrals, called Dual contributions, are in fact tree-level objects and thus give rise to the opportunity of bringing loop- and tree-contributions together, treating them simultaneously in a common Monte Carlo event generator. Initially introduced for one-loop scalar integrals, the applicability of the LTD has been expanded ever since. In this thesis, we show how to deal with Feynman graphs beyond simple poles by taking advantage of Integration By Parts (IBP) relations. Furthermore, we investigate the cancellation of singularities among Dual contributions as well as between real and virtual corrections. For the first time, a numerical implementation of the LTD was done in the form of a computer program that calculates one-loop scattering diagrams. We present details on the contour deformation employed alongside the results for scalar integrals up to the pentagon- and tensor integrals up to the hexagon-level.
[ { "created": "Wed, 23 Sep 2015 22:05:19 GMT", "version": "v1" } ]
2015-09-25
[ [ "Buchta", "Sebastian", "" ] ]
The Loop-Tree Duality (LTD) is a novel perturbative method in QFT that establishes a relation between loop-level and tree-level scattering amplitudes. This is achieved by directly applying the Residue Theorem to the loop-energy-integration. The result is a sum over all possible single cuts of the Feynman diagram in consideration integrated over a modified phase space. These single-cut integrals, called Dual contributions, are in fact tree-level objects and thus give rise to the opportunity of bringing loop- and tree-contributions together, treating them simultaneously in a common Monte Carlo event generator. Initially introduced for one-loop scalar integrals, the applicability of the LTD has been expanded ever since. In this thesis, we show how to deal with Feynman graphs beyond simple poles by taking advantage of Integration By Parts (IBP) relations. Furthermore, we investigate the cancellation of singularities among Dual contributions as well as between real and virtual corrections. For the first time, a numerical implementation of the LTD was done in the form of a computer program that calculates one-loop scattering diagrams. We present details on the contour deformation employed alongside the results for scalar integrals up to the pentagon- and tensor integrals up to the hexagon-level.
hep-ph/0405140
Jose Ramon Espinosa
J.R. Espinosa (IFT, Madrid)
Novel Opportunities for EW Breaking from Low-Scale SUSY Breaking
6 pages, 3 figures. Talk given at the XXXIXth Rencontres de Moriond on Electroweak Interactions and Unified Theories, La Thuile, Italy, 21-28 Mar 2004
null
null
IFT-UAM/CSIC-04-23
hep-ph
null
In supersymmetric scenarios with a low scale of SUSY breaking [sqrt{F}=O(TeV)] the conventional MSSM Higgs sector can be substantially modified, mainly because the Higgs potential contains additional effective quartic terms. The Higgs spectrum can be dramatically changed, and the lightest state can be much heavier than in usual SUSY scenarios. Novel opportunities for electroweak breaking arise, and the electroweak scale may be obtained in a less fine-tuned way for wide ranges of tan(beta) and the Higgs mass, offering a possible solution to the MSSM fine-tuning problem.
[ { "created": "Fri, 14 May 2004 17:09:18 GMT", "version": "v1" } ]
2007-05-23
[ [ "Espinosa", "J. R.", "", "IFT, Madrid" ] ]
In supersymmetric scenarios with a low scale of SUSY breaking [sqrt{F}=O(TeV)] the conventional MSSM Higgs sector can be substantially modified, mainly because the Higgs potential contains additional effective quartic terms. The Higgs spectrum can be dramatically changed, and the lightest state can be much heavier than in usual SUSY scenarios. Novel opportunities for electroweak breaking arise, and the electroweak scale may be obtained in a less fine-tuned way for wide ranges of tan(beta) and the Higgs mass, offering a possible solution to the MSSM fine-tuning problem.
2210.04465
Pablo G. Ortega
Pablo G. Ortega, David R. Entem, Francisco Fernandez
Strange hidden-charm $P_{\psi s}^\Lambda(4459)$ and $P_{\psi s}^\Lambda(4338)$ pentaquarks and additional $P_{\psi s}^\Lambda$, $P_{\psi s}^\Sigma$ and $P_{\psi ss}^N$ candidates in a quark model approach
8 pages, 1 figure, 7 tables
null
10.1016/j.physletb.2023.137747
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hidden-charm pentaquark-like $P_{\psi s}^\Lambda(4459)^0$ and $P_{\psi s}^\Lambda(4338)$ resonances are studied in a constituent quark model as molecular meson-baryon structures. Such states are found in the $J^P(I)=\frac{1}{2}^-(0)$ channel with masses and widths compatible with the experimental measurements in a coupled-channels calculation with all the parameters constrained from previous studies. Other candidates are explored in the $J^P=\frac{1}{2}^-$, $\frac{3}{2}^-$ and $\frac{5}{2}^-$ channels in the charm and bottom sectors, with isospins $0$ ($P_{\psi s}^\Lambda$ and $P_{\Upsilon s}^\Lambda$) and $1$ ($P_{\psi s}^\Sigma$ and $P_{\Upsilon s}^\Sigma$). Additionally, the formalism is extended to study the $P_{\psi ss}^N$ ($P_{\Upsilon ss}^N$) pentaquarks, where eight candidates are predicted as $\bar D_s \Xi_c$ molecules in $I=\frac{1}{2}$, with $J^P=\frac{1}{2}^-$, $\frac{3}{2}^-$ and $\frac{5}{2}^-$ for the charm sector and nine candidates as $B_s \Xi_b$ for the bottom one.
[ { "created": "Mon, 10 Oct 2022 07:20:30 GMT", "version": "v1" }, { "created": "Tue, 31 Jan 2023 15:18:41 GMT", "version": "v2" } ]
2023-02-22
[ [ "Ortega", "Pablo G.", "" ], [ "Entem", "David R.", "" ], [ "Fernandez", "Francisco", "" ] ]
Hidden-charm pentaquark-like $P_{\psi s}^\Lambda(4459)^0$ and $P_{\psi s}^\Lambda(4338)$ resonances are studied in a constituent quark model as molecular meson-baryon structures. Such states are found in the $J^P(I)=\frac{1}{2}^-(0)$ channel with masses and widths compatible with the experimental measurements in a coupled-channels calculation with all the parameters constrained from previous studies. Other candidates are explored in the $J^P=\frac{1}{2}^-$, $\frac{3}{2}^-$ and $\frac{5}{2}^-$ channels in the charm and bottom sectors, with isospins $0$ ($P_{\psi s}^\Lambda$ and $P_{\Upsilon s}^\Lambda$) and $1$ ($P_{\psi s}^\Sigma$ and $P_{\Upsilon s}^\Sigma$). Additionally, the formalism is extended to study the $P_{\psi ss}^N$ ($P_{\Upsilon ss}^N$) pentaquarks, where eight candidates are predicted as $\bar D_s \Xi_c$ molecules in $I=\frac{1}{2}$, with $J^P=\frac{1}{2}^-$, $\frac{3}{2}^-$ and $\frac{5}{2}^-$ for the charm sector and nine candidates as $B_s \Xi_b$ for the bottom one.
1001.2944
Xin Liu
Xin Liu and Zhen-Jun Xiao
Branching ratios of $B_c \to A P $ decays in the perturbative QCD approach
1+17 pges, 1 figure, refs. added and some clarifications made, accepted for publication in Phys.Rev.D
Phys.Rev.D81:074017,2010
10.1103/PhysRevD.81.074017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we calculate the branching ratios (BRs) of the 32 charmless hadronic $B_c \to A P$ decays ($A=a_1(1260),b_1(1235),K_1(1270),K_1(1400), f_1(1285),f_1(1420),h_1(1170),h_1(1380)$) by employing the perturbative QCD(pQCD) factorization approach. These considered decay channels can only occur via annihilation type diagrams in the standard model. From the numerical calculations and phenomenological analysis, we found the following results: (a) the pQCD predictions for the BRs of the considered $B_c$ decays are in the range of $10^{-6}$ to $10^{-8}$, while the CP-violating asymmetries are absent because only one type tree operator is involved here; (b) the BRs of $\Delta S= 0$ processes are generally much larger than those of $\Delta S =1$ ones due to the large CKM factor of $|V_{ud}/V_{us}|^2\sim 19$; (c) since the behavior for $^1P_1$ meson is much different from that of $^3P_1$ meson, the BRs of $B_c \to A(^1P_1) P$ decays are generally larger than that of $B_c \to A(^3P_1) P$ decays; (d) the pQCD predictions for the BRs of $B_c \to (K_1(1270), K_1(1400)) \etap $ and $(K_1(1270), K_1(1400)) K$ decays are rather sensitive to the value of the mixing angle $\theta_K$.
[ { "created": "Mon, 18 Jan 2010 02:33:04 GMT", "version": "v1" }, { "created": "Tue, 19 Jan 2010 02:08:11 GMT", "version": "v2" }, { "created": "Wed, 24 Mar 2010 01:20:29 GMT", "version": "v3" } ]
2010-04-22
[ [ "Liu", "Xin", "" ], [ "Xiao", "Zhen-Jun", "" ] ]
In this paper we calculate the branching ratios (BRs) of the 32 charmless hadronic $B_c \to A P$ decays ($A=a_1(1260),b_1(1235),K_1(1270),K_1(1400), f_1(1285),f_1(1420),h_1(1170),h_1(1380)$) by employing the perturbative QCD(pQCD) factorization approach. These considered decay channels can only occur via annihilation type diagrams in the standard model. From the numerical calculations and phenomenological analysis, we found the following results: (a) the pQCD predictions for the BRs of the considered $B_c$ decays are in the range of $10^{-6}$ to $10^{-8}$, while the CP-violating asymmetries are absent because only one type tree operator is involved here; (b) the BRs of $\Delta S= 0$ processes are generally much larger than those of $\Delta S =1$ ones due to the large CKM factor of $|V_{ud}/V_{us}|^2\sim 19$; (c) since the behavior for $^1P_1$ meson is much different from that of $^3P_1$ meson, the BRs of $B_c \to A(^1P_1) P$ decays are generally larger than that of $B_c \to A(^3P_1) P$ decays; (d) the pQCD predictions for the BRs of $B_c \to (K_1(1270), K_1(1400)) \etap $ and $(K_1(1270), K_1(1400)) K$ decays are rather sensitive to the value of the mixing angle $\theta_K$.
1108.1867
Heribert Weigert
Janne Kuokkanen, Kari Rummukainen, and Heribert Weigert
HERA-data in the light of small x evolution with state of the art NLO input
61 pages, 27 figures
null
10.1016/j.nuclphysa.2011.10.006
HIP-2011-23/TH
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Both total and diffractive cross sections from HERA are successfully confronted with JIMWLK evolution equations in the asymptotic pseudo-scaling region. We present a consistent, simultaneous description of both types of cross sections that includes NLO corrections in the form of running coupling and energy conservation corrections. The inclusion of energy conservation corrections allows to match all available data with x below .02 i.e. up to Q^2 of 1200 GeV^2. We discuss the effects of quark masses including charm, contrast asymptotic and pre-asymptotic fit strategies, and survey non-perturbative uncertainties related to impact parameter dependence.
[ { "created": "Tue, 9 Aug 2011 07:10:42 GMT", "version": "v1" } ]
2015-05-30
[ [ "Kuokkanen", "Janne", "" ], [ "Rummukainen", "Kari", "" ], [ "Weigert", "Heribert", "" ] ]
Both total and diffractive cross sections from HERA are successfully confronted with JIMWLK evolution equations in the asymptotic pseudo-scaling region. We present a consistent, simultaneous description of both types of cross sections that includes NLO corrections in the form of running coupling and energy conservation corrections. The inclusion of energy conservation corrections allows to match all available data with x below .02 i.e. up to Q^2 of 1200 GeV^2. We discuss the effects of quark masses including charm, contrast asymptotic and pre-asymptotic fit strategies, and survey non-perturbative uncertainties related to impact parameter dependence.
hep-ph/0405147
Frank Wilczek
Frank Wilczek
Yang-Mills Theory In, Beyond, and Behind Observed Reality
Solicited contribution to the volume ``Fifty Years of Yang-Mills Theory'' (WorldScientific). 12 pp
null
10.1142/9789812567147_0011
null
hep-ph
null
The character of jets is dominated by the influence of intrinsically nonabelian gauge dynamics. These proven insights into fundamental physics ramify in many directions, and are far from being exhausted. I will discuss three rewarding explorations from my own experience, whose point of departure is the hard Yang-Mills interaction, and whose end is not yet in sight. Given an insight so profound and fruitful as Yang and Mills brought us, it is in order to try to consider its broadest implications, which I attempt at the end.
[ { "created": "Mon, 17 May 2004 01:40:49 GMT", "version": "v1" } ]
2016-11-23
[ [ "Wilczek", "Frank", "" ] ]
The character of jets is dominated by the influence of intrinsically nonabelian gauge dynamics. These proven insights into fundamental physics ramify in many directions, and are far from being exhausted. I will discuss three rewarding explorations from my own experience, whose point of departure is the hard Yang-Mills interaction, and whose end is not yet in sight. Given an insight so profound and fruitful as Yang and Mills brought us, it is in order to try to consider its broadest implications, which I attempt at the end.
1104.0496
Jong-Phil Lee
Jong-Phil Lee
Black-hole bombs at the LHC
10 pages, 1 figure, 1 table. More discussions in the Introduction, minor changes; references updated
null
10.1142/S0217732312500381
null
hep-ph hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A particle scattered off by a rotating black hole can be amplified when the system is in the superradiant regime. If the system is surrounded by a mirror which reflects the particle back to the black hole the whole system forms a black-hole bomb, amplifying the original field exponentially. We show in this paper that higher dimensional black holes can also form black-hole bombs at the LHC. For a pion the $e$-folding time for the field amplification is $t_c\sim 10^{-23}-10^{-24}$ sec. If the lifetime of the black hole is long enough compared with $t_c$, we can observe severely amplified fields.
[ { "created": "Mon, 4 Apr 2011 08:48:06 GMT", "version": "v1" }, { "created": "Thu, 21 Apr 2011 10:12:43 GMT", "version": "v2" } ]
2015-05-27
[ [ "Lee", "Jong-Phil", "" ] ]
A particle scattered off by a rotating black hole can be amplified when the system is in the superradiant regime. If the system is surrounded by a mirror which reflects the particle back to the black hole the whole system forms a black-hole bomb, amplifying the original field exponentially. We show in this paper that higher dimensional black holes can also form black-hole bombs at the LHC. For a pion the $e$-folding time for the field amplification is $t_c\sim 10^{-23}-10^{-24}$ sec. If the lifetime of the black hole is long enough compared with $t_c$, we can observe severely amplified fields.
1805.11986
Ping Wang
Fangcheng He and P. Wang
Strange form factors of nucleon with nonlocal chiral effective Lagrangian
12 pages, 6 figures. arXiv admin note: substantial text overlap with arXiv:1711.05896
Phys. Rev. D 98, 036007 (2018)
10.1103/PhysRevD.98.036007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The strange form factors of nucleon are studied with the nonlocal chiral effective Lagrangian. One loop contributions from both octet and decuplet intermediate states are included. The relativistic regulator is obtained by the nonlocal Lagrangian where the gauge link is introduced to guarantee the local gauge symmetry. With the kaon loop, the calculated charge form factor is positive, while the magnetic form factor is negative. The strange magnetic moment is $-0.041^{+0.012}_{-0.014}$ with $\Lambda=0.9 \pm 0.1$ determined from the nucleon electromagnetic form factors. Our results are comparable with the recent lattice simulation.
[ { "created": "Tue, 29 May 2018 13:41:55 GMT", "version": "v1" } ]
2018-08-15
[ [ "He", "Fangcheng", "" ], [ "Wang", "P.", "" ] ]
The strange form factors of nucleon are studied with the nonlocal chiral effective Lagrangian. One loop contributions from both octet and decuplet intermediate states are included. The relativistic regulator is obtained by the nonlocal Lagrangian where the gauge link is introduced to guarantee the local gauge symmetry. With the kaon loop, the calculated charge form factor is positive, while the magnetic form factor is negative. The strange magnetic moment is $-0.041^{+0.012}_{-0.014}$ with $\Lambda=0.9 \pm 0.1$ determined from the nucleon electromagnetic form factors. Our results are comparable with the recent lattice simulation.
2210.15770
Pedro Dedin Neto
Pedro Dedin Neto
Open-Source Numerical Solver for Neutrino Collective Effects -- I: Isotropic Neutrino Gas
16 pages, 10 figures, typo correction in the title
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this paper, we introduce a new open-source code to find numerical solutions for the neutrino evolution considering neutrino-neutrino interactions, which result in the so-called collective effects. We first describe the theoretical background of this type of evolution, explaining the polarization vector formalism in which we implement our numerical code. We then show the results for different neutrino systems. In this first paper, we focus on the case of an isotropic neutrino gas, exploring a mono-energetic scenario and one with a spectral distribution. The resulting code of this work is available at https://github.com/pedrodedin/Neutrino-Collective-Effects.
[ { "created": "Thu, 27 Oct 2022 21:03:27 GMT", "version": "v1" }, { "created": "Fri, 10 Feb 2023 16:35:41 GMT", "version": "v2" } ]
2023-02-13
[ [ "Neto", "Pedro Dedin", "" ] ]
In this paper, we introduce a new open-source code to find numerical solutions for the neutrino evolution considering neutrino-neutrino interactions, which result in the so-called collective effects. We first describe the theoretical background of this type of evolution, explaining the polarization vector formalism in which we implement our numerical code. We then show the results for different neutrino systems. In this first paper, we focus on the case of an isotropic neutrino gas, exploring a mono-energetic scenario and one with a spectral distribution. The resulting code of this work is available at https://github.com/pedrodedin/Neutrino-Collective-Effects.
0805.2267
Lorenzo Magnea
Mrinal Dasgupta, Lorenzo Magnea, Gavin Salam
Analytical studies for non-perturbative QCD of jets at hadron colliders
5 pages, 2 figures; talks presented by M. Dasgupta at the "Rencontres de Moriond on QCD and Hadronic interactions" and by L. Magnea at the "Rencontres de Physique de la Vallee d'Aoste", La Thuile, Italy, 02-03/2008
null
null
MAN/HEP/2008/7, DFTT-9/2008
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by the success of analytical models for non-perturbative effects, used to investigate event shape variables at LEP and HERA, we apply them to a study of jets at hadron colliders such as the Tevatron and the LHC. We find that simple analytical estimates are able to shed considerable light on issues that could previously be tackled only through Monte-Carlo simulations, for example the role of different non-perturbative effects in various jet algorithms. In this context, we also provide testable numerical results for the commonly studied inclusive-jet $p_t$ distribution, and we introduce new observables that could be employed to verify our calculations.
[ { "created": "Thu, 15 May 2008 11:36:37 GMT", "version": "v1" } ]
2008-05-16
[ [ "Dasgupta", "Mrinal", "" ], [ "Magnea", "Lorenzo", "" ], [ "Salam", "Gavin", "" ] ]
Inspired by the success of analytical models for non-perturbative effects, used to investigate event shape variables at LEP and HERA, we apply them to a study of jets at hadron colliders such as the Tevatron and the LHC. We find that simple analytical estimates are able to shed considerable light on issues that could previously be tackled only through Monte-Carlo simulations, for example the role of different non-perturbative effects in various jet algorithms. In this context, we also provide testable numerical results for the commonly studied inclusive-jet $p_t$ distribution, and we introduce new observables that could be employed to verify our calculations.
hep-ph/9408384
Michael Dine
M. Dine, A.E. Nelson and Y. Shirman
Dynamical Supersymmetry Breaking Simplified
(25 pages; also 2 figures in an uuencoded PostScript file) SCIPP 94/21,UW/PT 94-07. Two equations corrected; gluino and squark masses are now nearly equal
Phys. Rev. D 51, 1362 (1995)
10.1103/PhysRevD.51.1362
null
hep-ph
null
We present a model in which supersymmetry is dynamically broken at comparatively low energies. Previous efforts to construct simple models of this sort have been hampered by the presence of axions. The present model, which exploits an observation of Bagger, Poppitz and Randall to avoid this problem, is far simpler than previous constructions. Models of this kind do not suffer from the naturalness difficulties of conventional supergravity models, and make quite definite predictions for physics over a range of scales from $100$'s of GeV to $1000$'s of TeV. Thus ``Renormalizable Visible Sector Models'' are a viable alternative to more conventional approaches. Our approach also yields a viable example of hidden sector dynamical supersymmetry breaking.
[ { "created": "Tue, 30 Aug 1994 01:59:44 GMT", "version": "v1" }, { "created": "Wed, 14 Sep 1994 00:16:18 GMT", "version": "v2" }, { "created": "Mon, 3 Oct 1994 20:14:14 GMT", "version": "v3" } ]
2019-08-17
[ [ "Dine", "M.", "" ], [ "Nelson", "A. E.", "" ], [ "Shirman", "Y.", "" ] ]
We present a model in which supersymmetry is dynamically broken at comparatively low energies. Previous efforts to construct simple models of this sort have been hampered by the presence of axions. The present model, which exploits an observation of Bagger, Poppitz and Randall to avoid this problem, is far simpler than previous constructions. Models of this kind do not suffer from the naturalness difficulties of conventional supergravity models, and make quite definite predictions for physics over a range of scales from $100$'s of GeV to $1000$'s of TeV. Thus ``Renormalizable Visible Sector Models'' are a viable alternative to more conventional approaches. Our approach also yields a viable example of hidden sector dynamical supersymmetry breaking.
hep-ph/9506249
Andras Patkos
A. Patk\'os
Effective Models of the Electroweak Phase Transition
9 pages latex, no figs., to appear in Procs. of PASCOS/Hopkins 1995 Conference
null
null
UUITP-11/95
hep-ph
null
The consecutive integration over the distinct mass scales ${\cal O}(T),{\cal O}(gT)$ leads to a hierarchy of effective models for the electroweak phase transition. Different techniques for the realisation of such strategy are reviewed. Advantages and difficulties resulting from the use of reduced models are discussed.
[ { "created": "Tue, 6 Jun 1995 17:22:13 GMT", "version": "v1" } ]
2007-05-23
[ [ "Patkós", "A.", "" ] ]
The consecutive integration over the distinct mass scales ${\cal O}(T),{\cal O}(gT)$ leads to a hierarchy of effective models for the electroweak phase transition. Different techniques for the realisation of such strategy are reviewed. Advantages and difficulties resulting from the use of reduced models are discussed.
hep-ph/0210322
Makiko Nio
T. Kinoshita and M. Nio
Revised $\alpha^4$ term of lepton $g-2$ from the Feynman diagrams containing an internal light-by-light scattering subdiagram
4 pages, 2 figures. The abstract is modified. The current levels of precision in lepton g-2 are mentioned
Phys.Rev.Lett.90:021803,2003
10.1103/PhysRevLett.90.021803
CLNS 02/1804
hep-ph
null
The $\alpha^4$ contribution to the lepton $g-2$ from a gauge-invariant set of 18 Feynman diagrams containing a light-by-light scattering subdiagram internally has been reevaluated by a method independent of the previous approach. Comparison of two methods revealed a program error in the first version. Correcting this error, the contributions of these 18 diagrams become -0.990 72 (10)$(\alpha/\pi)^4$ and -4.432 43 (58)$(\alpha/\pi)^4$ for the electron and muon $g-2$, respectively. The correction is not large enough to affect the comparison between theory and experiment for the muon $g-2$, but it does alter the inferred value for the fine structure constant $\alpha^{-1}$ by 6 ppb.
[ { "created": "Thu, 24 Oct 2002 07:12:18 GMT", "version": "v1" }, { "created": "Fri, 29 Nov 2002 01:48:21 GMT", "version": "v2" } ]
2008-11-26
[ [ "Kinoshita", "T.", "" ], [ "Nio", "M.", "" ] ]
The $\alpha^4$ contribution to the lepton $g-2$ from a gauge-invariant set of 18 Feynman diagrams containing a light-by-light scattering subdiagram internally has been reevaluated by a method independent of the previous approach. Comparison of two methods revealed a program error in the first version. Correcting this error, the contributions of these 18 diagrams become -0.990 72 (10)$(\alpha/\pi)^4$ and -4.432 43 (58)$(\alpha/\pi)^4$ for the electron and muon $g-2$, respectively. The correction is not large enough to affect the comparison between theory and experiment for the muon $g-2$, but it does alter the inferred value for the fine structure constant $\alpha^{-1}$ by 6 ppb.
1209.0280
Mrinal Kumar Das
Mrinal Kumar Das, Debasish Borah and Rinku Mishra
Quasi-Degenerate Neutrinos in Type II Seesaw Models
Version 2: Typos corrected, texts+tables rearranged, conclusion unchanged. Accepted for publication in Physical Review D
Phys. Rev. D86 095006 (2012)
10.1103/PhysRevD.86.095006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an analysis of normal and inverted hierarchical neutrino mass models within the framework of tri-bi-maximal (TBM) mixing. Considering the neutrinos to be quasi-degenerate (QDN), we study two different neutrino mass models with mass eigenvalues $(m_1, -m_2, m_3)$ and $(m_1, m_2, m_3)$ for both normal hierarchical (NH) and inverted hierarchical (IH) cases. Parameterizing the neutrino mass matrix using best fit oscillation and cosmology data for a QDN scenario, we find the right-handed Majorana mass matrix using type I seesaw formula for two types of Dirac neutrino mass matrices: charged lepton (CL) type and up quark (UQ) type. Incorporating the presence of type II seesaw term which arises naturally in generic left-right symmetric models (LRSM) along with type I term, we compare the predictions for neutrino mass parameters with the experimental values. Within such a framework and incorporating both oscillation as well as cosmology data, we show that QDN scenario of neutrino masses can still survive in nature with some minor exceptions. A viable extension of the standard model with an abelian gauged flavor symmetry is briefly discussed which can give rise to the desired structure of the Dirac and Majorana mass matrices.
[ { "created": "Mon, 3 Sep 2012 09:18:54 GMT", "version": "v1" }, { "created": "Wed, 17 Oct 2012 04:19:47 GMT", "version": "v2" } ]
2012-11-07
[ [ "Das", "Mrinal Kumar", "" ], [ "Borah", "Debasish", "" ], [ "Mishra", "Rinku", "" ] ]
We present an analysis of normal and inverted hierarchical neutrino mass models within the framework of tri-bi-maximal (TBM) mixing. Considering the neutrinos to be quasi-degenerate (QDN), we study two different neutrino mass models with mass eigenvalues $(m_1, -m_2, m_3)$ and $(m_1, m_2, m_3)$ for both normal hierarchical (NH) and inverted hierarchical (IH) cases. Parameterizing the neutrino mass matrix using best fit oscillation and cosmology data for a QDN scenario, we find the right-handed Majorana mass matrix using type I seesaw formula for two types of Dirac neutrino mass matrices: charged lepton (CL) type and up quark (UQ) type. Incorporating the presence of type II seesaw term which arises naturally in generic left-right symmetric models (LRSM) along with type I term, we compare the predictions for neutrino mass parameters with the experimental values. Within such a framework and incorporating both oscillation as well as cosmology data, we show that QDN scenario of neutrino masses can still survive in nature with some minor exceptions. A viable extension of the standard model with an abelian gauged flavor symmetry is briefly discussed which can give rise to the desired structure of the Dirac and Majorana mass matrices.
1609.06685
Roberto Bonciani
Roberto Bonciani, Vittorio Del Duca, Hjalte Frellesvig, Johannes M. Henn, Francesco Moriello, and Vladimir A. Smirnov
Two-loop planar master integrals for Higgs$\to 3$ partons with full heavy-quark mass dependence
46 pages, 5 figures, ancillary files provided
null
10.1007/JHEP12(2016)096
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the analytic computation of all the planar master integrals which contribute to the two-loop scattering amplitudes for Higgs$\to 3$ partons, with full heavy-quark mass dependence. These are relevant for the NNLO corrections to fully inclusive Higgs production and to the NLO corrections to Higgs production in association with a jet, in the full theory. The computation is performed using the differential equations method. Whenever possible, a basis of master integrals that are pure functions of uniform weight is used. The result is expressed in terms of one-fold integrals of polylogarithms and elementary functions up to transcendental weight four. Two integral sectors are expressed in terms of elliptic functions. We show that by introducing a one-dimensional parametrization of the integrals the relevant second order differential equation can be readily solved, and the solution can be expressed to all orders of the dimensional regularization parameter in terms of iterated integrals over elliptic kernels. We express the result for the elliptic sectors in terms of two and three-fold iterated integrals, which we find suitable for numerical evaluations. This is the first time that four-point multiscale Feynman integrals have been computed in a fully analytic way in terms of elliptic functions.
[ { "created": "Wed, 21 Sep 2016 19:06:39 GMT", "version": "v1" } ]
2017-02-01
[ [ "Bonciani", "Roberto", "" ], [ "Del Duca", "Vittorio", "" ], [ "Frellesvig", "Hjalte", "" ], [ "Henn", "Johannes M.", "" ], [ "Moriello", "Francesco", "" ], [ "Smirnov", "Vladimir A.", "" ] ]
We present the analytic computation of all the planar master integrals which contribute to the two-loop scattering amplitudes for Higgs$\to 3$ partons, with full heavy-quark mass dependence. These are relevant for the NNLO corrections to fully inclusive Higgs production and to the NLO corrections to Higgs production in association with a jet, in the full theory. The computation is performed using the differential equations method. Whenever possible, a basis of master integrals that are pure functions of uniform weight is used. The result is expressed in terms of one-fold integrals of polylogarithms and elementary functions up to transcendental weight four. Two integral sectors are expressed in terms of elliptic functions. We show that by introducing a one-dimensional parametrization of the integrals the relevant second order differential equation can be readily solved, and the solution can be expressed to all orders of the dimensional regularization parameter in terms of iterated integrals over elliptic kernels. We express the result for the elliptic sectors in terms of two and three-fold iterated integrals, which we find suitable for numerical evaluations. This is the first time that four-point multiscale Feynman integrals have been computed in a fully analytic way in terms of elliptic functions.
hep-ph/0003089
A. Perez-Lorenzana
R. N. Mohapatra, A. P\'erez-Lorenzana and C. A. de S. Pires
Inflation in Models with Large Extra Dimensions Driven by a Bulk Scalar Field
6 pages, LaTeX file, no figures. Minor changes. Final version to appear in Phys. Rev D
Phys.Rev.D62:105030,2000
10.1103/PhysRevD.62.105030
UMD-PP-00-062
hep-ph astro-ph hep-th
null
We discuss inflation in models with large extra dimensions, driven by a bulk scalar field. The brane inflaton is then a single effective field, obtained from the bulk scalar field by scaling. The self interaction terms of the effective brane inflaton are then naturally suppressed. The picture is consistent with a fundamental string scale in the TeV range without the problem of a superlight inflaton. If hybrid inflation is considered, the right prediction for the density perturbations as observed by COBE can be obtained without any fine tunning. The bulk inflaton then decays preferentially into brane Higgses and reheating follows.
[ { "created": "Thu, 9 Mar 2000 21:31:59 GMT", "version": "v1" }, { "created": "Thu, 16 Mar 2000 21:04:37 GMT", "version": "v2" }, { "created": "Wed, 26 Jul 2000 16:18:20 GMT", "version": "v3" }, { "created": "Fri, 1 Sep 2000 20:48:27 GMT", "version": "v4" } ]
2008-11-26
[ [ "Mohapatra", "R. N.", "" ], [ "Pérez-Lorenzana", "A.", "" ], [ "Pires", "C. A. de S.", "" ] ]
We discuss inflation in models with large extra dimensions, driven by a bulk scalar field. The brane inflaton is then a single effective field, obtained from the bulk scalar field by scaling. The self interaction terms of the effective brane inflaton are then naturally suppressed. The picture is consistent with a fundamental string scale in the TeV range without the problem of a superlight inflaton. If hybrid inflation is considered, the right prediction for the density perturbations as observed by COBE can be obtained without any fine tunning. The bulk inflaton then decays preferentially into brane Higgses and reheating follows.
1806.07615
Stefano Morisi
Franco Buccella, Damiano F. G. Fiorillo, Gennaro Miele, Stefano Morisi, Ofelia Pisanti, and Pietro Santorelli
Neutrino phenomenology from leptogenesis
15 pages, 2 figures
null
10.1140/epjc/s10052-018-6299-6
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Assuming a type-I seesaw mechanism for neutrino mass generation and invoking a baryogengesis via leptogenesis scenario, we consider a reasonable hierarchical structure for Dirac neutrino mass matrix, similar to up-type quark mass matrix. These hypotheses imply a relevant connection between high scale CP violation and low energy one. By requiring a compact heavy neutrino mass spectrum, which allows to circumvent Davidson-Ibarra limit, one can obtain an efficient leptogenesis restricting the allowed region for low energy neutrino parameters. Once the oscillating parameters are taken inside a $3\sigma$ range, through the numerical resolution of the leptogenesis Boltzmann equations one gets the following allowed intervals for the lightest neutrino mass and the Dirac CP phase: $-0.90\pi<\delta<-0.75\pi$ and $m_1\sim( 0.002 - 0.004)$ eV.
[ { "created": "Wed, 20 Jun 2018 08:58:34 GMT", "version": "v1" } ]
2018-11-14
[ [ "Buccella", "Franco", "" ], [ "Fiorillo", "Damiano F. G.", "" ], [ "Miele", "Gennaro", "" ], [ "Morisi", "Stefano", "" ], [ "Pisanti", "Ofelia", "" ], [ "Santorelli", "Pietro", "" ] ]
Assuming a type-I seesaw mechanism for neutrino mass generation and invoking a baryogengesis via leptogenesis scenario, we consider a reasonable hierarchical structure for Dirac neutrino mass matrix, similar to up-type quark mass matrix. These hypotheses imply a relevant connection between high scale CP violation and low energy one. By requiring a compact heavy neutrino mass spectrum, which allows to circumvent Davidson-Ibarra limit, one can obtain an efficient leptogenesis restricting the allowed region for low energy neutrino parameters. Once the oscillating parameters are taken inside a $3\sigma$ range, through the numerical resolution of the leptogenesis Boltzmann equations one gets the following allowed intervals for the lightest neutrino mass and the Dirac CP phase: $-0.90\pi<\delta<-0.75\pi$ and $m_1\sim( 0.002 - 0.004)$ eV.
2205.14486
Tania Robens
Tania Robens
TRSM Benchmark Planes -- Snowmass White Paper
14 pages, 7 figures; contribution to Snowmass 2021
null
null
RBI-ThPhys-2022-21
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this whitepaper, I briefly review the Benchmark Planes in the Two-Real-Singlet Model (TRSM), a model that enhances the Standard Model (SM) scalar sector by two real singlets that obey a $\mathbb{Z}_2\,\otimes\,\mathbb{Z}_2'$ symmetry. In this model, all fields acquire a vacuum expectation value, such that the model contains in total 3 CP-even neutral scalars that can interact with each other. All interactions with SM-like particles are inherited from the SM-like doublet via mixing. I remind the readers of the previously proposed benchmark planes, and briefly discuss possible production at future Higgs factories.
[ { "created": "Sat, 28 May 2022 16:59:49 GMT", "version": "v1" } ]
2022-05-31
[ [ "Robens", "Tania", "" ] ]
In this whitepaper, I briefly review the Benchmark Planes in the Two-Real-Singlet Model (TRSM), a model that enhances the Standard Model (SM) scalar sector by two real singlets that obey a $\mathbb{Z}_2\,\otimes\,\mathbb{Z}_2'$ symmetry. In this model, all fields acquire a vacuum expectation value, such that the model contains in total 3 CP-even neutral scalars that can interact with each other. All interactions with SM-like particles are inherited from the SM-like doublet via mixing. I remind the readers of the previously proposed benchmark planes, and briefly discuss possible production at future Higgs factories.
1901.07385
Satoshi Nakamura
S. X. Nakamura (Univ. Science and Technology of China), K. Tsushima (Univ. Cruzeiro do Sul)
$Z_c(4430)$ and $Z_c(4200)$ as triangle singularities
6 pages, 5 figures; published version; one figure on the cutoff-dependence added
Phys. Rev. D 100, 051502 (2019)
10.1103/PhysRevD.100.051502
LFTC-19-5/43
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
$Z_c(4430)$ discovered by the Belle and confirmed by the LHCb in $\bar{B}^0\to\psi(2S)K^-\pi^+$ is generally considered to be a charged charmonium-like state that includes minimally two quarks and two antiquarks. $Z_c(4200)$ found in $\bar{B}^0\to J/\psi K^-\pi^+$ by the Belle is also a good candidate of a charged charmonium-like state. We demonstrate that kinematical singularities in triangle loop diagrams induce a resonance-like behavior that can consistently explain the properties (mass, width, and Argand plot) of $Z_c(4430)$ and $Z_c(4200)$ from the experimental analyses. The triangle diagrams include only experimentally well-established hadrons. Applying this idea to $\Lambda_b^0\to J/\psi p\pi^-$, we also identify triangle singularities that behave like $Z_c(4200)$, but no triangle diagram is available for $Z_c(4430)$. This is consistent with the LHCb's finding that their description of the $\Lambda_b^0\to J/\psi p\pi^-$ data is significantly improved by including a $Z_c(4200)$ contribution while $Z_c(4430)$ seems to hardly contribute. Even though the proposed mechanisms have uncertainty in the absolute strengths which are currently difficult to estimate, they are certainly a compelling alternative to tetraquark-based interpretations of $Z_c(4430)$ and $Z_c(4200)$.
[ { "created": "Tue, 22 Jan 2019 15:04:10 GMT", "version": "v1" }, { "created": "Mon, 9 Sep 2019 15:31:14 GMT", "version": "v2" } ]
2019-09-18
[ [ "Nakamura", "S. X.", "", "Univ. Science and Technology of China" ], [ "Tsushima", "K.", "", "Univ. Cruzeiro do Sul" ] ]
$Z_c(4430)$ discovered by the Belle and confirmed by the LHCb in $\bar{B}^0\to\psi(2S)K^-\pi^+$ is generally considered to be a charged charmonium-like state that includes minimally two quarks and two antiquarks. $Z_c(4200)$ found in $\bar{B}^0\to J/\psi K^-\pi^+$ by the Belle is also a good candidate of a charged charmonium-like state. We demonstrate that kinematical singularities in triangle loop diagrams induce a resonance-like behavior that can consistently explain the properties (mass, width, and Argand plot) of $Z_c(4430)$ and $Z_c(4200)$ from the experimental analyses. The triangle diagrams include only experimentally well-established hadrons. Applying this idea to $\Lambda_b^0\to J/\psi p\pi^-$, we also identify triangle singularities that behave like $Z_c(4200)$, but no triangle diagram is available for $Z_c(4430)$. This is consistent with the LHCb's finding that their description of the $\Lambda_b^0\to J/\psi p\pi^-$ data is significantly improved by including a $Z_c(4200)$ contribution while $Z_c(4430)$ seems to hardly contribute. Even though the proposed mechanisms have uncertainty in the absolute strengths which are currently difficult to estimate, they are certainly a compelling alternative to tetraquark-based interpretations of $Z_c(4430)$ and $Z_c(4200)$.
hep-ph/9612320
null
D. Rainwater, D. Summers, D. Zeppenfeld
Multijet Structure of High E_T Hadronic Collisions
11 pages, RevTeX, Postscript version also available at http://phenom.physics.wisc.edu/pub/preprints/1996/madph-96-978.ps.Z or at ftp://phenom.physics.wisc.edu/pub/preprints/1996/madph-96-978.ps.Z
Phys.Rev.D55:5681-5684,1997
10.1103/PhysRevD.55.5681
MADPH-96-978, CERN-TH/96-334
hep-ph
null
Multijet events at large transverse energy (sum E_T > 420 GeV) and large multijet invariant mass (M_jets > 600 GeV) have been studied by the CDF Collaboration at the Fermilab Tevatron. The observed jet multiplicity distribution can be understood in a QCD inspired exponentiation model, in regions of phase space which require going beyond fixed order perturbation theory.
[ { "created": "Tue, 10 Dec 1996 23:59:30 GMT", "version": "v1" } ]
2014-11-17
[ [ "Rainwater", "D.", "" ], [ "Summers", "D.", "" ], [ "Zeppenfeld", "D.", "" ] ]
Multijet events at large transverse energy (sum E_T > 420 GeV) and large multijet invariant mass (M_jets > 600 GeV) have been studied by the CDF Collaboration at the Fermilab Tevatron. The observed jet multiplicity distribution can be understood in a QCD inspired exponentiation model, in regions of phase space which require going beyond fixed order perturbation theory.
hep-ph/0307107
Amarjit Soni
Amarjit Soni
Lattice Matrix Elements and CP Violation in B and K Physics: Status and Outlook
Invited talk at the 9th International Symposium on Particles, Strings and Cosmology (PASCOS 03), Mumbai (Bombay) India,3-8 Jan 2003
Pramana 62:415-438,2004
10.1007/BF02705099
BNL-HET-03/14
hep-ph
null
Status of lattice calculations of hadron matrix elements along with CP violation in B and in K systems is reviewed. Lattice has provided useful input which, in conjunction with experimenatl data, leads to the conclusion that CP-odd phase in the CKM matrix plays the dominant role in the observed asymmetry in $B \to \psi K_s$. It is now quite likely that any beyond the SM, CP-odd, phase will cause only small deviations in B-physics. Search for the effects of the new phase(s) will consequently require very large data samples as well as very precise theoretical predictions. Clean determination of {\it all} the angles of the unitarity triangle therefore becomes essential. In this regard $B \to K D^0$ processes play a unique role. Regarding K-decays, remarkable progress made by theory with regard to maintenance of chiral symmetry on the lattice is briefly discussed. First application already provide quantitaive information on $B_K$ and the $\Delta I=1/2$ rule. The enhancement in $Re A_0$ appears to arise solely from tree operators, esp. $Q_2$; penguin contribution to $Re A_0$ appears to be very small. However, improved calculations are necessary for $\epsilon^'/epsilon$ as there the contributions of QCD penguins and electroweak penguins largely seem to cancel. There are good reasons, though, to believe that these cancellations will not survive improvements that are now underway. Importance of determining the unitarity triangle purely from K-decays is also emphasized.
[ { "created": "Tue, 8 Jul 2003 04:08:51 GMT", "version": "v1" } ]
2010-11-23
[ [ "Soni", "Amarjit", "" ] ]
Status of lattice calculations of hadron matrix elements along with CP violation in B and in K systems is reviewed. Lattice has provided useful input which, in conjunction with experimenatl data, leads to the conclusion that CP-odd phase in the CKM matrix plays the dominant role in the observed asymmetry in $B \to \psi K_s$. It is now quite likely that any beyond the SM, CP-odd, phase will cause only small deviations in B-physics. Search for the effects of the new phase(s) will consequently require very large data samples as well as very precise theoretical predictions. Clean determination of {\it all} the angles of the unitarity triangle therefore becomes essential. In this regard $B \to K D^0$ processes play a unique role. Regarding K-decays, remarkable progress made by theory with regard to maintenance of chiral symmetry on the lattice is briefly discussed. First application already provide quantitaive information on $B_K$ and the $\Delta I=1/2$ rule. The enhancement in $Re A_0$ appears to arise solely from tree operators, esp. $Q_2$; penguin contribution to $Re A_0$ appears to be very small. However, improved calculations are necessary for $\epsilon^'/epsilon$ as there the contributions of QCD penguins and electroweak penguins largely seem to cancel. There are good reasons, though, to believe that these cancellations will not survive improvements that are now underway. Importance of determining the unitarity triangle purely from K-decays is also emphasized.
2201.04414
Jing Song
Jing Song, L.R.Dai, E.Oset
How much is the compositeness of a bound state constrained by $a$ and $r_0$? The role of the interaction range
null
null
10.1140/epja/s10050-022-00753-3
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an approach that allows one to obtain information on the compositeness of molecular states from combined information of the scattering length of the hadronic components, the effective range, and the binding energy. We consider explicitly the range of the interaction in the formalism and show it to be extremely important to improve on the formula of Weinberg obtained in the limit of very small binding and zero range interaction. The method allows obtaining good information also in cases where the binding is not small. We explicitly apply it to the case of the deuteron and the $D^{*}_{s0}(2317)$ and $D^{*}_{s1}(2460)$ states and determine simultaneously the value of the compositeness within a certain range, as well as get qualitative information on the range of the interaction.
[ { "created": "Wed, 12 Jan 2022 10:58:30 GMT", "version": "v1" }, { "created": "Tue, 7 Jun 2022 18:15:32 GMT", "version": "v2" } ]
2022-08-10
[ [ "Song", "Jing", "" ], [ "Dai", "L. R.", "" ], [ "Oset", "E.", "" ] ]
We present an approach that allows one to obtain information on the compositeness of molecular states from combined information of the scattering length of the hadronic components, the effective range, and the binding energy. We consider explicitly the range of the interaction in the formalism and show it to be extremely important to improve on the formula of Weinberg obtained in the limit of very small binding and zero range interaction. The method allows obtaining good information also in cases where the binding is not small. We explicitly apply it to the case of the deuteron and the $D^{*}_{s0}(2317)$ and $D^{*}_{s1}(2460)$ states and determine simultaneously the value of the compositeness within a certain range, as well as get qualitative information on the range of the interaction.
1608.02671
Omar Gustavo Miranda
B. C. Canas, E. A. Garces, O. G. Miranda, M. Tortola, J. W. F. Valle
The weak mixing angle from low energy neutrino measurements: a global update
11 pages, 5 figures, report no. IFIC/16-59
null
10.1016/j.physletb.2016.08.047
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Taking into account recent theoretical and experimental inputs on reactor fluxes we reconsider the determination of the weak mixing angle from low energy experiments. We perform a global analysis to all available neutrino-electron scattering data from reactor antineutrino experiments, obtaining sin^2(theta_W) = 0.252 \pm 0.030. We discuss the impact of the new theoretical prediction for the neutrino spectrum, the new measurement of the reactor antineutrino spectrum by the Daya Bay collaboration, as well as the effect of radiative corrections. We also reanalyze the measurements of the nu_e-e cross section at accelerator experiments including radiative corrections. By combining reactor and accelerator data we obtain an improved determination for the weak mixing angle, sin^2(theta_W) = 0.254 \pm 0.024.
[ { "created": "Tue, 9 Aug 2016 01:13:55 GMT", "version": "v1" } ]
2016-09-07
[ [ "Canas", "B. C.", "" ], [ "Garces", "E. A.", "" ], [ "Miranda", "O. G.", "" ], [ "Tortola", "M.", "" ], [ "Valle", "J. W. F.", "" ] ]
Taking into account recent theoretical and experimental inputs on reactor fluxes we reconsider the determination of the weak mixing angle from low energy experiments. We perform a global analysis to all available neutrino-electron scattering data from reactor antineutrino experiments, obtaining sin^2(theta_W) = 0.252 \pm 0.030. We discuss the impact of the new theoretical prediction for the neutrino spectrum, the new measurement of the reactor antineutrino spectrum by the Daya Bay collaboration, as well as the effect of radiative corrections. We also reanalyze the measurements of the nu_e-e cross section at accelerator experiments including radiative corrections. By combining reactor and accelerator data we obtain an improved determination for the weak mixing angle, sin^2(theta_W) = 0.254 \pm 0.024.
1211.5550
Paolo Bolzoni
P. Bolzoni
Timelike structure functions and hadron multiplicities
Talk given at the XXI International Baldin Seminar on High Energy Physics Problems,September 10-15, 2012, JINR, Dubna, Russia
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk we discuss the results obtained in the new approach that we recently introduced to consider and include both the perturbative and nonperturbative contributions to the evolution of the gluon and quark avarage multiplicities. We report on our progresses in solving a longstanding puzzle of QCD. The new formalism is motivated by recent important theoretical developments in timelike small-x resummation which are also discussed mostly from an historical point of view. We have extended our global analysis to fit the available data adding the strong coupling constant as a fit parameter. In this way our best fit gives $\alpha_s(M_z)=0.124\pm 0.005$ and for the corresponding $\chi^2$ we have obtained a further improvement.
[ { "created": "Fri, 23 Nov 2012 16:50:57 GMT", "version": "v1" } ]
2012-11-26
[ [ "Bolzoni", "P.", "" ] ]
In this talk we discuss the results obtained in the new approach that we recently introduced to consider and include both the perturbative and nonperturbative contributions to the evolution of the gluon and quark avarage multiplicities. We report on our progresses in solving a longstanding puzzle of QCD. The new formalism is motivated by recent important theoretical developments in timelike small-x resummation which are also discussed mostly from an historical point of view. We have extended our global analysis to fit the available data adding the strong coupling constant as a fit parameter. In this way our best fit gives $\alpha_s(M_z)=0.124\pm 0.005$ and for the corresponding $\chi^2$ we have obtained a further improvement.
1111.1909
Radoslaw Ryblewski
Rados{\l}aw Ryblewski
Flow characteristics and strangeness production in the framework of highly-anisotropic and strongly-dissipative hydrodynamics
Presented at Strangeness in Quark Matter 2011, Sept. 18--24, Cracow, Poland
Acta Physica Polonica B Proceedings Supplement vol. 5 (2012) page 457
10.5506/APhysPolBSupp.5.457
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recently formulated model of highly-anisotropic and strongly dissipative hydrodynamics is used in 3+1 dimensions to describe flow characteristics and strangeness production in Au+Au collisions at the highest RHIC beam energy. Our results show very weak dependence on the initial momentum anisotropy, provided the anisotropic phase lasts no longer than 1 fm/c.
[ { "created": "Tue, 8 Nov 2011 13:57:13 GMT", "version": "v1" } ]
2012-04-16
[ [ "Ryblewski", "Radosław", "" ] ]
The recently formulated model of highly-anisotropic and strongly dissipative hydrodynamics is used in 3+1 dimensions to describe flow characteristics and strangeness production in Au+Au collisions at the highest RHIC beam energy. Our results show very weak dependence on the initial momentum anisotropy, provided the anisotropic phase lasts no longer than 1 fm/c.
hep-ph/0111033
Nikolai Sushilov
S.I.Kruglov
Wave Equation Solutions and Pair Production for Arbitrary Spin Particles
26 pages, LaTeX
Int.J.Theor.Phys.,40:515-536,2001
null
null
hep-ph
null
We investigate the theory of particles with arbitrary spin and magnetic moment in the Lorentz representation (0,s)X(s,0) in an external constant and uniform electromagnetic field. We obtain the density matrix of free particles in pure spin states. The differential probability of pair producing particles with arbitrary spin by an external constant and uniform electromagnetic field is found using the exact solutions. We calculate the imaginary and real parts of the Lagrangian in an electromagnetic field that takes into account the vacuum polarization.
[ { "created": "Sat, 3 Nov 2001 21:47:36 GMT", "version": "v1" } ]
2011-07-19
[ [ "Kruglov", "S. I.", "" ] ]
We investigate the theory of particles with arbitrary spin and magnetic moment in the Lorentz representation (0,s)X(s,0) in an external constant and uniform electromagnetic field. We obtain the density matrix of free particles in pure spin states. The differential probability of pair producing particles with arbitrary spin by an external constant and uniform electromagnetic field is found using the exact solutions. We calculate the imaginary and real parts of the Lagrangian in an electromagnetic field that takes into account the vacuum polarization.
1403.2440
Yue-Liang Wu
Zhuo Liu, Yue-Liang Wu
Leptonic CP Violation and Wolfenstein Parametrization for Lepton Mixing
18 pages, 5 figures, sources of CP-violating phases are clarified, references added
null
10.1016/j.physletb.2014.04.049
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate a general structure of lepton mixing matrix resulting from the SU$_F$(3) gauge family model with an appropriate vacuum structure of SU$_F$(3) symmetry breaking. It is shown that the lepton mixing matrix can be parametrized by using the Wolfenstein parametrization method to characterize its deviation from the tri-bimaximal mixing. A general analysis for the allowed leptonic CP-violating phase $\delta_e$ and the leptonic Wolfenstein parameters $\lambda_e$, $A_e$, $\rho_e$ is carried out based on the observed lepton mixing angles. We demonstrate how the leptonic CP violation correlates to the leptonic Wolfenstein parameters. It is found that the phase $\delta_e$ is strongly constrained and only a large or nearly maximal leptonic CP-violating phase $|\delta_e| \simeq 3\pi/4 \sim \pi/2$ is favorable when $\lambda_e > 0.15 $. In particular, when taking $\lambda_e$ to be the Cabbibo angle $\gl_e\simeq \lambda \simeq 0.225$, a sensible result for leptonic Wolfenstein parameters and CP violation is obtained with $ A_e=1.40$, $\rho_e=0.20$, $\delta_{e}\sim 101.76\;^o$, which is compatible with the one in quark sector. An interesting correlation between leptons and quarks is observed, which indicates a possible common origin of masses and mixing for the charged-leptons and quarks.
[ { "created": "Tue, 11 Mar 2014 00:07:29 GMT", "version": "v1" }, { "created": "Tue, 25 Mar 2014 23:57:19 GMT", "version": "v2" } ]
2015-06-19
[ [ "Liu", "Zhuo", "" ], [ "Wu", "Yue-Liang", "" ] ]
We investigate a general structure of lepton mixing matrix resulting from the SU$_F$(3) gauge family model with an appropriate vacuum structure of SU$_F$(3) symmetry breaking. It is shown that the lepton mixing matrix can be parametrized by using the Wolfenstein parametrization method to characterize its deviation from the tri-bimaximal mixing. A general analysis for the allowed leptonic CP-violating phase $\delta_e$ and the leptonic Wolfenstein parameters $\lambda_e$, $A_e$, $\rho_e$ is carried out based on the observed lepton mixing angles. We demonstrate how the leptonic CP violation correlates to the leptonic Wolfenstein parameters. It is found that the phase $\delta_e$ is strongly constrained and only a large or nearly maximal leptonic CP-violating phase $|\delta_e| \simeq 3\pi/4 \sim \pi/2$ is favorable when $\lambda_e > 0.15 $. In particular, when taking $\lambda_e$ to be the Cabbibo angle $\gl_e\simeq \lambda \simeq 0.225$, a sensible result for leptonic Wolfenstein parameters and CP violation is obtained with $ A_e=1.40$, $\rho_e=0.20$, $\delta_{e}\sim 101.76\;^o$, which is compatible with the one in quark sector. An interesting correlation between leptons and quarks is observed, which indicates a possible common origin of masses and mixing for the charged-leptons and quarks.
1904.02997
Tobias Wistisen
Tobias N. Wistisen and Antonino Di Piazza
Complete treatment of single-photon emission in planar channeling
null
Phys. Rev. D 99, 116010 (2019)
10.1103/PhysRevD.99.116010
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Approximate solutions of the Dirac equation are found for ultrarelativistic particles moving in a periodic potential, which depends only on one coordinate, transverse to the largest component of the momentum of the incoming particle. As an example we employ these solutions to calculate the radiation emission of positrons and electrons trapped in the planar potential found between the (110) planes in Silicon. This allows us to compare with the semi-classical method of Baier, Katkov and Strakhovenko, which includes the effect of spin and photon recoil, but neglects the quantization of the transverse motion. For high-energy electrons, the high-energy part of the angularly integrated photon energy spectrum calculated with the found wave functions differs from the corresponding one calculated with the semi-classical method. However, for lower particle energies it is found that the angularly integrated emission energy spectra obtained via the semi-classical method is in fairly good agreement with the full quantum calculation except that the positions of the harmonic peaks in photon energy and the photon emission angles are shifted.
[ { "created": "Fri, 5 Apr 2019 11:30:41 GMT", "version": "v1" } ]
2019-06-19
[ [ "Wistisen", "Tobias N.", "" ], [ "Di Piazza", "Antonino", "" ] ]
Approximate solutions of the Dirac equation are found for ultrarelativistic particles moving in a periodic potential, which depends only on one coordinate, transverse to the largest component of the momentum of the incoming particle. As an example we employ these solutions to calculate the radiation emission of positrons and electrons trapped in the planar potential found between the (110) planes in Silicon. This allows us to compare with the semi-classical method of Baier, Katkov and Strakhovenko, which includes the effect of spin and photon recoil, but neglects the quantization of the transverse motion. For high-energy electrons, the high-energy part of the angularly integrated photon energy spectrum calculated with the found wave functions differs from the corresponding one calculated with the semi-classical method. However, for lower particle energies it is found that the angularly integrated emission energy spectra obtained via the semi-classical method is in fairly good agreement with the full quantum calculation except that the positions of the harmonic peaks in photon energy and the photon emission angles are shifted.